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MDK 01.01. Basics of fitting and assembly and electrical work. Section 1 " . Locksmith, fitter and assembly work. »Serov Valery Sergeevich master p / o

Topic. Markup 1. The essence and purpose of markup. 2. Tools, fixtures and materials used for marking. 3. Preparation of surfaces for marking. 4. Rules for performing markup techniques. 5. Typical defects when marking, the reasons for their appearance and methods of prevention. 6. Mechanization of marking works. Study questions:

1. Essence and purpose of marking Marking is an operation of drawing on the surface of a workpiece lines (lines) defining the contours of the part being manufactured, which is part of some technological operations. Depending on the characteristics of the technological process, planar and spatial markings are distinguished. Plane markings are used in the processing of sheet material and profile rolled products, as well as parts on which marking marks are applied in the same plane. Spatial marking is the drawing of scratches on the surfaces of the workpiece, interconnected by mutual arrangement.

2. Tools, fixtures and materials used for marking Fig. 2.1. Scribes: a - one-sided with a ring; b - one-sided with a handle; в - bilateral; d-double-sided with a handle Scribes are the simplest tool for drawing the contour of a part on the surface of the workpiece and represent a rod with a pointed end of the working part.

Continuation of the 2nd question Reismas is used for drawing marks on the vertical plane of the workpiece (Fig. 2.2). Rice. 2.2. Reismas: 1 - vertical scale bar; 2 - scribe, fixed on a vertical stand

Continuation of question 2 Marking compasses are used to draw arcs of circles and dividing segments and angles into equal parts (Fig. 2.3). Rice. 2.3. A marking compass: a - simple; b - spring

Continuation of question 2 Kerners (Fig. 2.4) are made of U7A tool steel. Hardness along the length of the working part (15 ... 30 mm) should be HRC 52 ... 57. Fig. 2.4. Kerner Fig. 2.5. Kerner Yu.V. Kozlovsky: 1 - building; 2 - striker; 3 - impact head; 4 - bushing; 5, 13 - springs; b, 11 - legs; 7.8 - nuts; P, 10 - replaceable needles; 12,14- screws

Continuation of question 2 Fig. 2.6. Tools for applying center holes: a - bell; b, c - center-finder square: 1 - square; 2 - ruler; d - center finder-protractor: 1 - locking screw; 2 - ruler; 3 - square; 4 - protractor

Continuation of question 2 Fig. 2.7. Automatic mechanical center punch: 1 - center punch; .2 - rod; 3,5,6- component parts of the center punch; 4 - flat spring; 7, 11 - springs; 8 - drummer; 9 - shoulder; 10 - biscuit Fig. 2.8. Electric center punch: 1 - sleeve; 2 - rod; 3 - center punch; 4.7 - springs; 5 - coil; b - drummer; 8 - case; 9 - electrical circuit

Continuation of question 2 Fig. 2.9. Special center punch: a - without load; b-with load; 1 - stand; 2 - center punch; 3 - rack; 4 - screw; 5 - legs; b - cargo

Continuation of question 2 Marking plates (Fig. 2.10) are cast from gray cast iron, their working surfaces must be precisely processed. Rice. 2.10. Marking plate: a - on a stand; b - on the table

Continuation of question 2 Marking prisms (Fig. 2.11) are made with one and two prismatic grooves. In terms of accuracy, prisms of normal and increased accuracy are distinguished. Rice. 2.11. Marking prisms: type I - one-sided; type II - four-sided; h, h 1, h 2, h 3, h 4 - depth of V -shaped grooves

Continuation of question 1 When marking stepped shafts, use prisms with a screw support (Fig. 2.12) and prisms with movable cheeks, or adjustable prisms (Fig. 2.13). Rice. 2.12. Screw-supported prism Fig. 2.13. Adjustable prism

Continuation of question 2 Squares with a shelf (Fig. 2.14) are used for both planar and spatial markings. Rice. 2.14. Square with a shelf: a - square; b, c - examples of use

Continuation of question 2 Marking boxes (Fig. 2.15) are used to be installed on them when marking workpieces of complex shape. Rice. 2.15. Marking box: a - general view; b - example of use

Continuation of question 2 Marking wedges (Fig. 2.16) are used when it is necessary to adjust the position of the workpiece to be marked in height within insignificant limits. Rice. 2.16. Marking wedge

Continuation of question 2 Jacks (Fig. 2.17) are used in the same way as adjustable wedges for adjusting and aligning the position of the workpiece to be marked in height, if the part has a sufficiently large mass. Rice. 2.17. Jacks with ball (a) and prismatic (b) support for the workpiece

Continuation of question 2 In order for the marking risks to be clearly visible on the surface of the workpiece to be marked, this surface should be painted. To paint the surfaces to be marked, use: a solution of chalk in water with the addition of wood glue, which ensures reliable adhesion of the coloring composition to the surface of the workpiece to be marked, and a desiccant, which facilitates the rapid drying of this composition; copper sulfate, which is copper sulphate and, as a result of the ongoing chemical reactions, ensures the formation of a thin and durable copper layer on the surface of the workpiece; quick-drying paints and enamels.

3. PREPARATION OF SURFACES FOR MARKING. Preparatory work for marking includes the preparation of dyes, preparation of surfaces for painting and painting itself. Chalk with the addition of wood glue and drier is diluted to the consistency of liquid sour cream. Copper sulfate is dissolved in water in a ratio of 1:10 or solid copper sulfate is used to rub the surface of the workpiece to be marked. Varnishes and enamels are used ready-made. Before painting, the surface to be marked must be cleaned of dirt, dust, traces of scale and degreased. Painting is performed by applying the composition to the surface of the workpiece evenly, in a thin layer. To apply the coloring composition, use a brush and a swab.

Continuation of 3 questions Then markup is performed. First, the base is determined from which the risks will be applied. Marking risks are usually applied in the following order. First all horizontal, then vertical, then oblique, and last but not least - circles, arcs and roundings. After making sure that the markings are correct, all lines are nibbled so that they do not get erased when processing the part. Cores should be shallow and split in half by marking lines. The marking is done in several ways: according to the drawing, according to the template, according to the sample and in place.

4. Rules for performing markup techniques. one . The layer of the coloring compound applied to the surface of the workpiece should be thin, uniform in thickness and completely cover the surface to be marked. 2. When drawing the risks, precisely align the ruler with the original marks on the part and press it tightly against the workpiece. 3. Before taking the risk, you should make sure that the scribe (compass) is well sharpened. 4. The risk of drawing the scribe with one continuous movement along the ruler, do not apply the risk twice in the same place, as this leads to its bifurcation.

Continuation of question 4 5. When punching the marking marks: make sure that the punch is sharpened correctly, re-sharpen if necessary; Perform punching with light hammer blows on the punch so that the depth of the punch is about 0.5 mm. lines of large circles with a diameter of more than 15 mm are numbered evenly in 6 ... 8 places, arcs in mates should be numbered with smaller gaps between grooves than in straight sections; the points of conjugation and intersection of the marks must be numbered; the center of the hole or arc is bent deeper than the line, the hole diameter should be approximately 1.0 mm.

Continuation of question 4 6. When marking a hole or arc, precisely set the compass solution to the required size, firmly fix the compass solution with the clamping screw of the compass arc. When drawing an arc, tilt the compass slightly in the direction of movement. 7. If, when mating straight and curved lines, they do not coincide, paint over the marked place of the part and repeat the markings. 8. When marking using a template (sample), press it tightly against the part, make sure that it does not move during the marking process. 9. When marking the center at the end of a cylindrical part with a center finder (bell), follow the installation of the center finder strictly along the axis of the part, check the marking accuracy with a sliding center finder.

Continuation of question 4 10. When marking the center on the end face of a cylindrical part with a center-finder square, make sure that the shelves of the center-finder fit tightly to the cylindrical part of the part. 11. When marking the center of the hole of the part using a sliding center-finder, observe the perpendicularity of the installation of the wooden block with the plate of the axis of the hole. 12. When marking "from the edge" of the machined part, firmly press the flange of the square with a wide base to the edge of the part. 13. When marking "from the center lines", the dimensions are counted from two control core depressions located at the edges of these lines.

5 . TYPICAL DEFECTS WHEN PERFORMING THE MARKING, THE REASONS OF THEIR APPEARANCE AND METHODS OF PREVENTION Defect Cause Prevention method Double risk The ruler was weakly pressed against the part. The risk was carried out twice in the same place. The marking was carried out with a blunt scribe. Press the ruler tightly against the part, at the risk of making only one time. Sharpen the scribe The core hole is not at risk When setting the center punch, its tip did not get at risk. Punching was done with a blunt center punch. The center punch shifted from the risks before hitting with a hammer. Place the center punch exactly in the recess of the risks, hold it firmly when punching. If necessary, sharpen the center punch. Forked or offset risk of a marked arc or circle. The support (fixed) leg of the compass is blunt. Shallow core depth at the center of a circle or arc. Strong pressing on the movable leg of the compass in the process of marking Make the markings only with a compass with sharply sharpened legs, smooth, not strong movements of the compass, tilting it in the direction of movement

Continuation of question 5 Risks are not linked to each other. Risk ruler is inaccurately established. Displacement of the line during the application of the risks. The size of the compass is inaccurately set; the support leg of the compass jumped out of the core recess while drawing the marks. Follow all marking rules exactly. Hold the straight edge and compasses firmly during the marking process. Scores not parallel or perpendicular to each other. The ruler for risks and arcs is not precisely set. Circular clamping screw loosely attached. Set the ruler exactly according to the initial marks. Press it firmly against the part. Observe the clamping of the compass legs. The angles between the marks do not correspond to the data. The core holes in the initial marks are displaced. The sequence for constructing the corner has been disrupted. The ruler is inaccurately set for the rice and core depressions. Apply core depressions only after the deepening of the risks. Observe the sharpening of the center punch and scribe. Precisely position the ruler along the lines and core holes The marked contour does not match the pattern The template was not pressed tightly to the workpiece surface during marking, as a result of which it shifted when drawing the marking marks. Press the template firmly against the workpiece surface during marking. If possible, fix the template to the workpiece with a clamp

Continuation of question 5 When marking with a scraper, the risk is not straight line The mark to be marked is unstably installed. The gauge needle is loosely attached to the rack. Dirt has gotten on the scribe under the base of the flight Check that the part is firmly installed (without swinging) on ​​the scaffold. Wipe down the screed plate thoroughly before marking. Fasten the marking needle firmly on the gauge rod Centers of holes and cylindrical parts of the parts do not match Poorly defined centers of holes and cylindrical parts of the part Check the center markings

6. MECHANIZATION OF LOCAL WORKS Fig. 2.18. Coordinate marking machine with digital indication (all dimensions are in millimeters): 1 - measuring head; 2 - traverse; 3 - marking sludge; 4 - table; 5 - bed

Continuation of question 6 Fig. 2.19. Coordinate marking machine for small parts (all dimensions are in millimeters): 1 - measuring head; 2 - traverse; 3 - marking needle; 4 - table; 5 - bed

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GBPOU SMT "SORMOVSKY MECHANICAL TECHNICUM NAMED AFTER THE HERO OF THE SOVIET UNION PA SEMENOV" MDK 01.01. "Fundamentals of fitting and assembly and electrical work" THEME: CUTTING OF METAL Developed by VS Serov master p / o, highest category

CUTTING OF METAL 1. Purpose and purpose of plumbing. 2. Tools used in felling. 3. Sharpening of the cutting tool. 4. Basic rules and methods of performing work during felling. 5. Hand-held power tools. 6. Typical defects during felling, the reasons for their appearance and methods of prevention Educational questions:

1. Purpose and purpose of locksmith felling A felling operation is the operation of removing a layer of material from a workpiece, as well as cutting metal (sheet, strip, profile) into parts with cutting tools (chisel, crosscutter or grooving machine using a hammer). The following works are performed by felling: removal of excess layers of material from the surfaces of workpieces (cutting off casting, welded seams, cutting edges for welding, etc.); trimming of edges and burrs on forged and cast blanks; cutting into pieces of sheet material; punching holes in sheet material; cutting oil grooves, etc.

2. TOOLS FOR CUTTING Fig. 1. Locksmith's chisel: a - general view of the chisel and its working part; b - angle of sharpening and action of forces; c - cutting elements during felling; P is the cutting force; w 1, w 2 - components of the cutting force; β, β 1, β 2 - taper angles; γ is the rake angle; a - back angle; δ - cutting angle A metalwork chisel (Fig. 1) consists of three parts: working, middle, impact. As with any cutting, the cutting part of the tool is a wedge (Fig. 1 a).

Continuation of question 2 Kreutzmeisel (Fig. 2) differs from the chisel by a narrower cutting edge. Kreutzmeisel is used for punching grooves, cutting keyways and the like. Rice. 2. Kreutzmeisel Groove (Fig. 3.) is used for cutting out lubricating grooves in bushings and bushings of plain bearings and profile grooves for special purposes. Rice. 3. Grooving

Continuation of question 2 Locksmith hammers (Fig. 4.) are used in felling as an impact tool to create cutting force and are of two types - with a round (Fig. 4, a) and square (Fig. 4, b) striker. Rice. 4. Bench hammers: a - with a round striker; b - with a square striker; c - ways of attaching the handle

3. SHARPENING OF THE CUTTING TOOL The sharpening of the cutting tool is carried out on the sharpening machines Fig. 5. Sharpening machine: a - sharpening machine unit; b - template for control of sharpening angles; 1 - protective screen; 2 - casing; 3 - handyman

4. BASIC RULES AND METHODS OF PERFORMANCE OF WORKS AT CUTTING 1. When cutting sheet and strip metal up to 3 mm thick at the level of the vise jaws, the following rules should be observed: the part of the workpiece that goes into the shavings must be located above the level of the vise jaws; the risk on the workpiece must be exactly at the level of the vise jaws, the workpiece is not skewed; the workpiece should not protrude beyond the right end of the vise jaws; cutting along the vise level with the middle of the cutting edge of the tool, placing it at an angle of 45 ° to the workpiece (Fig. 6 b). The angle of inclination of the chisel, depending on the angle of sharpening of the working part, is from 30 to 35 ° (Fig. 6 a).

Continuation of question 4 Fig. 6. Cutting at the vise level: a and b - the angle of inclination of the chisel, respectively, in the vertical and horizontal planes

Continuation of question 4 2. When cutting strip (sheet) material on a slab (anvil), the following requirements should be met: the cutting edge of the chisel should not be sharpened in a straight line, but with a certain curvature (Fig. 7.); cut sheet material in a straight line, starting from the far edge of the sheet to the front, while the chisel should be located exactly along the marking risk. When cutting, move the sheet so that the impact point is approximately in the middle of the slab; when cutting out a blank of a curved profile from sheet material (Fig. 8.), leave an allowance of 1.0 ... 1.5 mm for its subsequent processing, for example, by filing;

Continuation of 4 questions, cutting the strip along the markings on both sides by about half the thickness of the strip, then break it in a vice or on the edge of the slab (anvil); adjust the impact force depending on the thickness of the material to be cut. Rice. 7. Cutting of sheet material Fig.8. Cutting a blank from sheet material

Continuation of question 4 3. When cutting a metal layer on a wide surface of the part, first, using a cross-cutter, cut grooves with a depth of 1.5 ... 2.0 mm over the entire surface of the part (Fig. 9 a), then chop off the remaining projections with a chisel (Fig. 9 b). Rice. 9. Cutting down material from a wide surface: a - cutting grooves; b - cutting down protrusions

Continuation of question 4 4. Cutting curved grooves on the workpiece with a grooving tool in one or several passes, depending on the material being processed and the requirements for the quality of processing. Adjust the volume of material to be cut by the slope of the groove and the force of impact on the tool. 5. When sharpening the tool, it is necessary to fulfill the following requirements: set the tool-holder of the sharpening machine so that the gap between the tool-hand and the grinding wheel does not exceed 3 mm; press the tool with the cutting part to the periphery of the grinding wheel, while resting on the handguard; periodically cool the tool with water by lowering it into a special container.

Continuation of 4 questions to check the angle of sharpening of the tool according to the template; monitor the symmetry of the tool blade about its axis. 6. When cutting and sharpening cutting tools, the following safety measures must be observed: install a protective screen on the workbench; firmly fix the workpiece in a vice; do not use a hammer, chisel, grooving machine, cracker with a flattened striker; do not use a hammer loosely attached to the handle; cut only with a sharpened tool; use personal protective goggles or a protective screen installed on the machine to avoid eye injuries.

5. HAND MECHANIZED TOOLS Fig. 10 . Manual pneumatic hammer: 1 - handle; 2 - fitting; 3 - starting device; 4 - valve; 5 - air distribution device; b - sleeve; 7 - drummer; 8 - trunk; 9 - chisel shank; 10 - end sleeve By the nature of the main movement, power tools with a reciprocating and rotary movement are distinguished.

Continuation of question 5 Fig. 11. Pneumatic grinder: 1 - spindle; 2 - casing; 3 - case; 4 - trigger; 5 - handle; b - grinding wheel Pneumatic grinding machines are used for cleaning welded seams and preparing surfaces for further processing.

6. TYPICAL DEFECTS AT CUTTING, REASONS OF THEIR APPEARANCE AND METHODS OF PREVENTION Defect Cause Method of prevention Cutting of sheet steel in a vise The chopped off edge of the detail is curved The part is weakly clamped in the vise Firmly fix the part in the vise The sides of the cut part are not aligned parallel. Skewing of the workpiece in the vise Observe the marking rules, precisely position the part in the vise according to the marking risk. "Torn" edge of the part Cutting was performed with too strong blows or a blunt chisel Before cutting, make sure that the chisel is sharpened correctly. Adjust the force of impacts depending on the thickness of the workpiece. The angle of inclination of the chisel must be at least 30 °

Continuation of question 6 Cutting grooves "Ragged" groove edges Incorrect sharpening of the crosscutter Grind the crosscutter with an undercut of the cutting edge Groove depth is not uniform along its length During the felling process, the slope of the crosscutter was not adjusted. Chips at the end of the groove Chamfer on the part is not chopped off Before cutting (especially for brittle metals), it is imperative to cut off a chamfer on the edge of the workpiece at the point of exit of the crosshead

Continuation of question 6 Cutting a layer of metal on a wide surface Rough blockages and hacks on the treated surface The felling was carried out with a blunt chisel. Incorrect chisel positioning during cutting. Uneven force of blows with a hammer on a chisel in the process of cutting It is most rational to cut down the protrusions between the grooves cut earlier by the "herringbone" method. Adjust the thickness of the layer to be removed by tilting the chisel Chips on the edge of the part Chamfers on the part are not chopped off Before cutting the wide surface of the part (especially fragile material), it is imperative to chop off chamfers from all edges of the part

Continuation of question 6 Cutting sheet, strip and bar steel on a plate Indirectly linear edge from a chopped part Violation of the rules for marking a part. The felling was not carried out according to the marking risk. Observe the straightness of the marking risks. Precisely position the chisel at risk. The edge of the chopped part has deep notches and chips. Incorrect sharpening of the chisel. Inaccurate setting of the chisel on the marking line. Cutting was done with too light blows with a "stuck nod" or blunt chisel. For sheet metal cutting, the chisel should be sharpened slightly round. To make the felling with vigorous blows without "tapping". Hold the chisel firmly at risk of marking

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GBPOU SMT "SORMOVSKY MECHANICAL TECHNICUM NAMED AFTER THE HERO OF THE SOVIET UNION P.A. SMYONOVA "MDK 01.01." Fundamentals of fitter-assembly and electrical work "THEME: BENDING OF METAL Developed by VS Serov master p / o, highest category

FLEXIBLE OF METAL 1. The essence and types of bending. 2. Tools, fixtures and materials used in bending. 3. Mechanization during bending. 4. Rules for performing work in manual bending of metal. 5. Typical defects during bending, reasons for their appearance and methods of prevention. Study questions:

1. The essence and types of bending Flexible (bending) is called an operation, as a result of which the workpiece takes the required shape (configuration) and dimensions by stretching the outer layers of the metal and compressing the inner ones. The total length of the workpieces when bending with rounding is calculated according to the following formula: where is the length of the workpiece straight sections; r 1, ...., r n - radii of the corresponding rounding; a 1 ..., and n - bend angles. Bending can be done manually, using various bending devices and using special bending machines.

2. TOOLS, DEVICES AND MATERIALS USED FOR FLEXING Fig. one . Bending on a mandrel: a-c - the sequence of the operation As tools when bending sheet material with a thickness of 0.5 mm, strip and bar material with a thickness of up to 6.0 mm, steel locksmith hammers with square and round strikers weighing from 500 to 1000 g are used , soft hammers, wooden hammers, pliers and round nose pliers.

Continuation of question 2 Fig. 2 Pliers Fig. 3. Round-nose pliers Pliers and round-nose pliers are used when bending profile rolled products with a thickness of less than 0.5 mm and wire.

Continuation of question 2 Fig. 4 . A device for bending the frame of a hacksaw machine: a, b - diagrams of using the device; в - finished frame; 1 - lever; 2 - roller; 3 - blank; 4 - mandrel; A, B - respectively, the upper and lower positions of the lever

Continuation of question 2 Fig. 5 . Device for ring bending Hot bending of pipes is performed after preheating with high frequency currents (HFC), in flame furnaces or forges, with gas acetylene torches or blowtorches, directly at the bending site. Fillers for bending pipes are selected depending on the material of the pipe, its size and the method of bending. Used as fillers: sand or rosin.

3 FLEXIBLE MECHANIZATION Fig. 6. Bending rollers: 1 - drive mechanism; 2 - top roll; 3 - bending sheet; 4 - plate; 5 - bottom roll

Continuation of question 3 Fig. 7. Press brake: a - general view; b - constructive scheme; c - the shape of the bent profile; 1 - slider frame; 2 - punch; 3 - matrix; 4 - lining; 5 - plate

Continuation of question 3 Fig. eight . Roller bending machine: a - three-roller: 1 - handle; 2 - upper roller; 3,4 - pressure rollers; 5 - clamps; b - four-roller: 1 - bed; 2.8 - handles; 3, 5 - leading rollers; 4.7 - pressure rollers; b - blank

Continuation of question 3 Fig. 9 . Machine for bending pipes with heating by high-frequency currents: 1 - bed; 2 - longitudinal feed mechanism; 3 - extension cord; 4 - bent pipe; 5 - sponges; b, 10- carriages; 7 - guide rollers; 8 - inductor holder; 9 - inductor; 11 - pressure roller; 12 - pressure roller carriage; 13 - cross feed screw; 14 - cross feed mechanism; 1 5 - limit switch; 16 - cooling system; 17 - lead screw; 18, 20 - handles; 19 - roller

4. Rules for performing work in manual bending of metal. one . When bending sheet and strip material in a vice, the marking line must be positioned exactly, without distortions, at the level of the vice jaws in the direction of the bend. 2. When bending parts such as corners, brackets of various configurations, hooks, rings and other parts from strips and bars, you should first calculate the length of the elements and the total length of the part sweep, while marking the bending points. 3. In the mass production of parts such as brackets, it is necessary to use mandrels, the dimensions of which correspond to the dimensions of the elements of the part, which excludes the current marking of bending points.

Continuation of question 4 When bending sheet and strip metal in fixtures, you must strictly adhere to the instructions attached to them. 5. When bending gas or water pipes by any method, the seam must be inside the bend.

5. TYPICAL DEFECTS DURING BENDING, REASONS OF THEIR APPEARANCE AND METHODS OF WARNING Defect Causes Method of prevention When bending the corner from the strip, it turned out to be skewed Incorrect fastening of the workpiece in the vice Fasten the strip so that the marking risk is exactly at the level of the vice jaws. Check the perpendicularity of the strip to the vice jaws with a square. The dimensions of the bent part do not correspond to the specified ones. Inaccurate calculation of the reamer, the mandrel is incorrectly selected. Precisely mark the bending points. Use mandrels that exactly match the given dimensions of the part. Dents "(cracks) when bending a pipe with filler The pipe is not packed tightly enough with filler. Place the pipe vertically when filling with filler (dry sand). Tap the pipe from all sides with a hammer.

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GBPOU SMT “SORMOVSKY MECHANICAL TECHNICAL SCHOOL NAMED AFTER THE HERO OF THE SOVIET UNION PA SEMENOV VS Serov, master p / o, highest category MDK 01.01. "Fundamentals of fitter-assembly and electrical work" THEME: METAL REDUCTION

Topic 5. EDITING METAL 1. Essence, purpose and methods of editing. 2. Tools and devices used for dressing. 3. Mechanization during straightening. 4. Basic rules for performing work when editing. 5. Typical defects during straightening, reasons for their appearance and methods of prevention. Study questions:

1. Essence, purpose and methods of straightening Straightening is an operation to straighten bent or warped metal, which can only be subjected to plastic materials: aluminum, steel, copper, brass, titanium. The straightening is carried out on special straightening plates, which are made of cast iron or steel. Editing of small parts can be done on forging anvils. Metal straightening is performed with hammers of various types, depending on the surface condition and material of the part being straightened.

Continuation of 1 question Editing is carried out in several ways: bending, stretching and smoothing. Bending straightening is used when straightening round (rods) and shaped material, which have a sufficiently large cross-section. In this case, hammers with steel strikers are used. Stretch straightening is used when straightening sheet material that has bulges or waviness. This is done with hammers with soft metal strikers or mallets. Flattening is used in cases where the workpiece has a very small thickness. Smoothing is carried out with wooden or metal bars.

2. TOOLS AND DEVICES USED IN THE EDIT Fig. one . Straightening plate On such plates, profile blanks and blanks from sheet and strip material, as well as rods from ferrous and non-ferrous metal are straightened.

Continuation of question 2 Fig. 2. Hammers with soft inserts: a - with prismatic; b - with cylindrical: 1 - pin; 2 - strikers; 3 - handle; 4 - the body of the Sledgehammer are hammers of a large mass (2.0 ... 5.0 kg) and are used to straighten round and profiled rolled products of a large cross-section in cases where the impact force applied by a conventional metalwork hammer is insufficient to straighten the deformed workpiece ...

Continuation of question 2 Mallets are hammers, the striking part of which is made of hard wood, they are ruled by sheet material made of high plasticity metals. A characteristic feature of straightening with mallets is that they practically do not leave marks on the straightened surface. Metal or wooden ironers (made of hard wood: beech, oak, boxwood) are designed for straightening (smoothing) sheet material of small thickness (up to 0.5 mm). This tool, as a rule, does not leave traces in the form of dents during processing.

3. MECHANIZATION WHEN EDITING Fig. 3. Manual press: a - straightening in the centers; b - straightening on prisms The simplest device for mechanizing straightening is a manual press (Fig. 3), with the help of which the straightening of profiled rolled stock and bar material is carried out.

Continuation of question 3 Fig. 4 . Correct machine: a - general view; b - dressing scheme; P - straightening force Fig. 5 . Correct rollers

4. BASIC RULES FOR PERFORMANCE OF WORKS WHEN LEVELING 1. When straightening strip and bar material (round, square or hexagonal section), the straightened part must touch the correct plate or anvil at least two points (Fig. 6). Rice. 6. Straightening of strip and bar material

Continuation of question 4 4. Editing of sheet material with a thickness of 0.5 ... 0.7 mm must be done using wooden mallets - mallets (Fig. 7). 5. When straightening ribbed strips (straightening), as well as sheet material with significant deformations, it is necessary to use the stretching straightening method (Fig. 8). Rice. 7. Editing sheet material with a mallet Fig. eight . Editing a strip that is curved along an edge

Continuation of question 4 6. Editing of strips with a helical bend must be performed in hand-held vise (Fig. 9, b). Rice. 9 . Straightening of a strip with a helical bend: a - a strip with a double bend; b - straightening the strip in hand-held vise

Continuation of question 4 7. Quality control of straightening should be carried out depending on the configuration of the workpiece and its initial state: by "eye" (Fig. 10) - visually, with a ruler, rolling on the plate; "On a pencil" (Fig. 11) - by rotating the straightened shaft in the centers of the manual screw press. 8. When straightening strip and bar material on a plate (anvil), use Fig. 10 . Checking the dressing visually Fig. eleven . Control of the “pencil” dressing with mittens; dressing is carried out with a hammer or a sledgehammer firmly attached to the handle.

6. TYPICAL DEFECTS WHEN CORRECTING, REASONS OF THEIR APPEARANCE AND METHODS OF WARNING Defect Cause Method of prevention After dressing a machined part, there are dents in it. straightening the machined cylindrical parts set on prisms After straightening the sheet material with a mallet or a hammer through a wooden adapter, the sheet is significantly deformed Insufficiently effective straightening methods were used Apply straightening method by stretching the metal along the edges of the bulge, alternating this method with straightening with direct impacts After straightening the strip is not straight along the edge The dressing process is not finished.

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GBPOU SMT "SORMOVSKY MECHANICAL TECHNICUM NAMED AFTER THE HERO OF THE SOVIET UNION PA SEMENOV" MDK 01.01. "Fundamentals of fitter-assembly and electrical installation work" THEME: METAL SAWING Developed by VS Serov master p / o, highest category

SAWING OF METAL 1. The essence and purpose of the operation of filing. 2. Tools used for filing. 3. Devices for filing. 4. Preparation of surfaces, the main types and methods of filing. 5. Rules for manual filing of flat, concave and convex surfaces. 6. Mechanization of work during filing. Tools for the mechanization of filing operations. Rules for performing work with mechanized sawing. 7. Typical defects when filing metal, the reasons for their appearance and methods of prevention. Study questions:

1. Essence and purpose of the filing operation Sawing is an operation to remove a layer of material from the surface of a workpiece using a cutting tool - a file, the purpose of which is to give the workpiece a given shape and size, as well as to ensure a given surface roughness. In plumbing practice, filing is used to process the following surfaces: - flat and curved; - flat, located at an external or internal angle; - flat parallel under a certain size between them; -shaped complex profile. In addition, filing is used to process grooves, grooves and protrusions. Distinguish between rough and final filing.

2. TOOLS USED WHEN SAWING Fig. 1. Types of notches: a - single; 6 - double; c - rasp The main working tools used for filing are files, rasps and needle files.

Continuation of question 2 Fig. 2. Shapes of file teeth: a - notched: β - cutting angle; γ is the rake angle; δ is the taper angle; α is the back angle; b - milled; c - extended Files are classified according to the number of cuts per 10 mm of file length into 6 classes. The notches are numbered from 0 to 5, while the smaller the number of the notch, the greater the distance between the notches and, accordingly, the larger the tooth.

Continuation of question 2 Fig. 3. Cross-sectional shapes of files and processed surfaces: a, b - flat; в - square; g - triangular; d - round; e - semicircular; g - rhombic; h - hacksaw

Continuation of question 2 Fig. 4. Rasps: a - flat blunt-pointed; 6 - flat pointed; c - round; g - semicircular; L is the length of the working part; / is the length of the handle; b is the width of the rasp; h is the thickness of the rasp; d - diameter of the rasp

Continuation of question 2 Fig. 5. Needles: a, b - flat; в - square; d, e - triangular; e - round; g - semicircular; h - olive-shaped; and - rhombic; k - trapezoidal; l - fillet

Continuation of question 2 The profile of the cross-section of the file is selected depending on the shape of the surface to be sawn: flat, flat side of the semicircular - for filing flat and convex curved surfaces; square, flat - for processing grooves, holes and openings of rectangular cross-section; flat, square, flat side of a semicircular - when filing surfaces located at an angle of 90 °; triangular - when filing surfaces located at an angle of more than 60 °; hacksaw, rhombic - for filing surfaces located at an angle of more than 10 °; triangular, round, semicircular, rhombic, square, hacksaw - for sawing holes (depending on their shape).

Continuation of question 2 The length of the file depends on the type of processing and the size of the processed surface and should be: -100 ... 160 mm - for filing thin plates; 160 ... 250 mm - for filing surfaces with a processing length of up to 50 mm; 250 ... 315 mm - with a processing length of up to 100 mm; -315 ... 400 mm - with a processing length of more than 100 mm; -100 ... 200 mm - for sawing holes in parts up to 10 mm thick; -315 ... 400 mm - for rough filing; -100 ... 160 mm - when finishing (files). The number of the cut is selected depending on the requirements for the roughness of the processed surface.

Continuation of question 2 Fig. 6. File handle Fig. 7. Quick-change handle for a file: 1 - sleeve; 2 - spring; 3 - glass; 4- nut; 5 - case

3. Devices for filing Fig. 8. Frame: 1- partition; 2 - working plates; 3 - screws Fig. 9. Plane basting: a - basting; b - basting in a vice with a workpiece; 1,2 - collars; 3 - working plane; 4 - blank

Continuation of question 3 Fig. 10. Sliding parallels a - rectangular; b - corner Fig. 11. Conductor: 1 - conductor; 2 - blank

Continuation of question 3 Fig. 12. Sawing prism: 1 - body; 2 - clamp; 3 -gon; 4 - ruler; 5-threaded hole; A - the guiding plane of the prism

Continuation of question 3 When working with a file, the cut is clogged with sawdust, so the file should be cleaned before further use. The method of cleaning files from sawdust and other processing products depends on the type of material being processed and the condition of the file surface: - after processing wood, rubber and fiber, the file should be immersed in hot water for 10 ... 15 minutes, and then cleaned with a steel scraper brush; - after processing with files of soft materials (lead, copper, aluminum), the notch is cleaned with a crusting brush; - oiled files are rubbed with a piece charcoal, then brushed with a scouring brush. Oil from the file surface can be removed with a caustic soda solution followed by rinsing and cleaning.

4. Preparation of surfaces, main types and methods of filing Preparation of surfaces for filing includes cleaning from oil, dirt, molding sand, scale. Cleaning is carried out with scouring brushes, as well as cutting off the remains of the gating system and bursting with a chisel, followed by cleaning with coarse sandpaper. The oil is removed with various solvents. The position of the worker during filing is most convenient when his body is turned at an angle of 45 ° to the jaws of the vice (Fig. 13, a). The left leg should be extended forward and be at a distance of about 150 ... 200 mm from the front edge of the workbench, and the right leg should be 200 ... 30 mm away from the left so that the angle between the feet is 60 ... 70 ° (Fig. . 13, b).

Continuation of question 4 Fig. 13. The position of the worker: a - the position of the hands and body; b - position of the legs

Continuation of question 4 Fig. 14. Position of hands during filing: a - on the handle; b - on the toe; c - when filing

Continuation of question 4 Fig. 15. Distribution of efforts during filing (balancing) The working stroke during filing is the movement of the file forward from the worker, the return stroke is idle, without pressure. Movement during the working stroke should be uniform, smooth, rhythmic, while both hands should move in a horizontal plane. It is not recommended to tear off the file from the workpiece during the return stroke.

Continuation of question 4 Fig. 16. Gripping the file with a "pinch" Finishing filing is carried out with personal files (No. 2 and 3) with less effort, which ensures the removal of small chips and obtaining a high quality surface. Finishing the surface after processing is carried out to improve its appearance using a personal file, which is taken with a "pinch".

Continuation of question 4 Finishing and grinding is carried out with short personal and velvet files (No. 4 and 5). The pressure on the file during this type of processing should be minimal. Sawing of narrow flat surfaces is carried out, as a rule, transversely, which ensures greater processing productivity. When filing wide flat surfaces, three methods are used: - after each double stroke of the file, it is moved in the transverse direction at a distance slightly less than the width of the file; -the file makes a complex movement forward and to the side across the workpiece; -Cross filing, in which processing is carried out alternately along the diagonals of the treated surface, and then along and across this surface.

5. Rules for manual filing of flat, concave and convex surfaces 1. Before starting work, it is necessary to check the conformity of the configuration and dimensions of the workpiece to the requirements of the drawing. 2. It is necessary to firmly fix the workpiece in a vice. 3. When performing fine finishing operations of filing, it is necessary to use overhead sponges. 4. The file number, length and section should be selected in accordance with the technical requirements for processing.

Continuation of question 5 Rules for filing flat surfaces 1. Choose a filing method, taking into account the surface to be treated: -transverse stroke - for narrow surfaces; - longitudinal stroke - for long surfaces; -Cross-stroke - for wide surfaces; - gripping the file with a "pinch" - for fine filing, finishing under a ruler and under the size of long narrow surfaces; - with the edge of a triangular file - when finishing the inner corner of mating surfaces. 2. A testing tool for checking the flatness of surfaces should be used while filing. 3. It is necessary to start fine filing of a flat surface only after rough filing of this surface is made exactly under the ruler.

Continuation of question 5 4. The checking tool to control the angle between the mating surfaces should be used only after fine filing of the base surface. 5. Use the tool for checking the dimension between parallel surfaces only after finishing filing of the base surface. 6. When checking flatness, angles and dimensions, observe the following rules: -Before checking, it is necessary to clean the treated surface with a broom or a rag, but never by hand; - to check, the workpiece should be released from the vice after processing; - a workpiece with a testing tool should be placed between the eyes and the light source;

Continuation of question 5 - you should not tilt the test (curved) ruler during flatness control using the "light slit" method; - you should not move the testing and measuring tools over the surface of the workpiece in order to avoid their premature wear; - measurements of dimensions should be made only after the surface is well sawn and checked with a ruler; -measurements of the part should be made in three or four places in order to increase the accuracy of measurements. 7. The final processing of flat narrow surfaces should be done with a longitudinal stroke.

Continuation of question 5 When filing curved surfaces, the following rules must be observed: 1. Choose the right file for filing curved surfaces: - flat and semicircular - for convex; -semicircular - for concave ones with a large (more than 20 mm) radius of curvature; - round - for concave ones with a small (up to 20 mm) radius of curvature. 2. Observe the correct coordination of movements and balancing of the file: - when filing a cylindrical roller (rod) fixed horizontally: at the beginning of the working stroke - the toe of the file is lowered down, the handle is raised up; in the middle of the working stroke - the file is located horizontally; at the end of the working stroke - the toe of the file is raised up, the handle is lowered down (Fig. 17, a);

Continuation of question 5 - when filing a cylindrical roller (rod) fixed vertically: at the beginning of the working stroke - the toe of the file is directed to the left; at the end of the working stroke - the toe of the file is directed forward (Fig. 17, b); - when filing a concave surface of a large radius of curvature during the working stroke, it is necessary to shift the file along the surface to the right or left, slightly turning it; - when filing concave surfaces of a small radius of curvature during the working stroke, it is necessary to make a rotational movement with a file; Rice. 17. Sawing a round rod: a - located horizontally; b - located vertically

Continuation of question 5 - finishing (finishing according to the template) of convex and concave surfaces should be done with a longitudinal stroke, holding the file with a "pinch". 4. Convex surfaces of flat parts must first be filed onto a polyhedron with an allowance of 0.5 mm, and then filed according to the marking and template. 5. Finishing should be done only after preliminary (rough) sawing of the surface using a template.

6. Mechanization of work during filing. Rice. 19. Sawing discs Fig. 20. Bora

Continuation of question 6 Fig. 21. Grinding heads: a - semicircular; b - round; c, d, e - conical; e - reverse conical; w - cylindrical

Continuation of question 6 Fig. 22. Electric filing machine with flexible shaft: 1 - chuck; 2- tool; 3.5 pulleys; 4 - belt. 6- flexible shaft. 7-electric motor; 8 - bracket; P - support.

Continuation of question 6 Fig. 23. Pneumatic filing machine: 1 - tool; 2 - cartridge; 3 - piston; 4 - rotary sleeve; 5 - piston box; 6- hose; 7- cover; 8 - trigger

Continuation of question 6 Fig. 24. Sawing machine with an abrasive belt: 1 - bracket; 2 - lamp; 3 - endless abrasive belt; 4 - table; 5 - base; b - power button

Continuation of question 6 Fig. 25. Stationary filing and cleaning machine: a - general view of the machine; b - executive unit; 1 - bed; 2 - casing; 3.5 - brackets; 4 - rack; 6 - stock; 7 - file; 8 - blank; 9 - table; 10, 12 - screws; 11 - starting pedal

Continuation of question 6 Rules for performing work with mechanized filing 1. It is necessary to choose the right tool for mechanized filing of curved surfaces: - cutter-cutter - for removing a large layer of metal or rough cleaning of a rough surface and burrs; -shaped round files - for precise (up to 0.05 mm) surface treatment; - Shaped grinding heads - for final cleaning of processed surfaces. 2. The shape of the tool should be selected depending on the shape of the surface to be treated. 3. Surface treatment with round rotating files must be carried out by fixing them with a shank in the chuck of a manual drilling machine with a power of at least 0.5 kW.

7. TYPICAL DEFECTS WHEN SAWING THE METAL, REASONS OF THEIR APPEARANCE AND METHODS OF WARNING Defect Cause Prevention method "Blockages" in the rear part of the part plane Vise set too high Adjust the height of the vise according to the growth "Blockages" in the front part of the workpiece plane Vise set too high low The same "Blocks" of the filing wide plane of the part Sawing was carried out only in one direction When filing a wide flat surface, successively alternate longitudinal, transverse and cross filing

Continuation of question 7 Defect Cause Prevention method Failed to file mating flat surfaces like charcoal The rules for filing mated flat surfaces were not followed. flat surface The square does not fit tightly to flat surfaces mated at an internal angle Poorly finished corner in mating Finish the corner between mating flat surfaces with the edge of a triangular file or file, make a slot in the corner of mating surfaces Unable to saw flat surfaces parallel but to each other The rules for filing flat surfaces are not observed First, exactly, under the ruler, and cleanly file the reference plane of the part. To make filing of the conjugate plane, alternating from the very beginning of work, regular check of its flatness with a ruler and the size of the rods with a compass. Determine the filing points by the gap between the jaws of the calipers and the surface to be filing, as well as by comparing the measurement results.

Continuation of question 7 Rough final finishing of the sawn-off surface Finishing was carried out with a "wood" file. Wrong surface finishing techniques were used. Surface finishing should be done only with a personal file after high-quality "filing under the surface ruler with a coarser file. Surface finish with a longitudinal stroke, using a file grip with a" pinch "The sawn round bar is not cylindrical (ovality, taper, cut ) Inappropriate sequence of filing and control When filing, more often measure the dimensions of the rod in different places and from different sides.

Continuation of question 7 Defect Cause Method of prevention The sawn curved surface of a flat part does not correspond to the profile of the control template The rules for filing curved linear surfaces of flat parts are not observed When filing convex surfaces, first file onto a polyhedron with a finishing allowance of 0.1 ... 0.2 mm, then finish with a longitudinal stroke, regularly checking the surface with a template. When filing in a curved surface with a small radius of curvature, the diameter of the round file must be less than twice the radius of the recess Sawed mating contour of the workpiece does not match the profile of the test template Incorrect processing sequence Observe the typical processing sequence: first cut flat parallel surfaces, then convex ones. Finish the processing by filing the concave parts of the surface, carefully observing the filing of the mating points. Finish with a longitudinal stroke

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GBPOU SMT "SORMOVSKY MECHANICAL TECHNICUM NAMED AFTER THE HERO OF THE SOVIET UNION PA SEMENOV" Section 1 ". Locksmith, fitter and assembly work. »THEME: CUTTING Developed by VS Serov master p / o, highest category

Sawing and fitting 1. The essence of sawing and fitting. 2. Basic rules for sawing and fitting parts. 3. Typical defects when sawing and fitting parts, the reasons for their appearance and how to prevent them. Study questions:

1. The essence of sawing and fitting Sawing is a type of filing. When sawing, a hole or opening is filed to ensure the specified shape and size after this hole or opening has been previously obtained by drilling, drilling the contour followed by cutting out the jumpers, sawing out an open contour (opening) with a hand hacksaw, punching, etc. quality control of processing (size and configuration) is carried out with special testing tools - templates, workings, inserts, etc. (Fig. 1) along with the use of universal measuring instruments.

Continuation of 1 question Fig. one . Template and insert: a - template; b - production; c - insert Fitting is a locksmith's operation for mutual fitting by filing methods of two mating parts (pairs). Fitted contours of pairs of parts are subdivided into closed (like holes) and open (like openings). One of the parts to be fitted (with a hole, opening) is called an armhole, and the part entering the armhole is called an insert.

2. Basic rules for sawing and fitting parts. Rules for sawing 1. It is rational to determine the method of preliminary formation of the openings and holes to be sawn: in parts up to 5 mm thick - by cutting, and in parts over 5 mm thick - by drilling or reaming, followed by cutting or cutting the bridges. 2. When drilling, reaming, punching out or cutting out bridges, it is necessary to strictly monitor the integrity of the marking lines, leaving a machining allowance of about 1 mm. 3. It is necessary to observe a rational sequence of processing openings and holes: first, process the straight sections of surfaces, and then - the curved sections associated with them.

Continuation of question 2 4. The process of sawing openings and holes should be periodically combined with checking their contours using a control template, insert or working out. 5. The corners of openings or openings must be cleaned with the edge of a file of the appropriate cross-sectional profile (No. 3 or 4) or with file files, checking the quality of the workings. 6. Finish the surface of the holes with a longitudinal stroke. 7. For the final calibration and finishing of the hole, punching, broaching and piercing on a screw or pneumatic press should be used (Fig. 2). Rice. 2. Cylindrical firmware

Continuation of question 2 8. The work should be considered completed when the control template or insert completely, without swinging, enters the opening or hole, and the clearance (gap) between the template (insert, working out) and the sides of the opening (hole) contour is uniform. Fitting rules: 1. Fitting of two parts (pairs) to each other should be carried out in the following order: first, one part of a pair (usually with external contours) is made and finished - an insert, and then it is marked and fitted (fitted ) another mating part is the armhole. 2. The quality of the fit should be checked by the clearance: in the gap between the parts of the pair, the clearance should be uniform. 3. If the contour of the pair of parts - the liner and the armhole - is symmetrical, they should be mated without effort when flanged by 180 °, with a uniform gap.

3. Typical defects when sawing and fitting parts, causes of their appearance and ways of preventing Defect Cause Method of prevention Misalignment of the opening or hole in relation to the base surface of the part Misalignment during drilling or reaming. Insufficient control when sawing Carefully observe the perpendicularity of the tool to the base surface of the workpiece when drilling and reaming the opening (hole). In the process of work, systematically check the perpendicularity of the plane of the opening to be sawn (hole) of the base surface of the part. Non-observance of the shape of the opening (hole) Sawing was carried out without checking the shape of the opening (hole) according to the template (inserts Шу). "Gouges" for the marking when cutting the contour First, cut along the marking (0.5 mm to the marking line). The final processing of the opening (hole) should be carried out with a thorough check of its shape and dimensions with measuring tools or a template (insert)

Continuation of question 3 Mismatch of symmetric contours of the fitted pair (liner and armhole) when they are flipped by 180 ° One of the parts of the pair (counter-pattern) is not made symmetrically. adjoins the other (insert) in the corners Blockages in the corners of the armhole Observe the rules for processing parts. Cut the corners of the armhole with a hacksaw or saw the corners of the armhole with a round file The gap between the parts to be fitted is greater than permissible Violation of the sequencing of the scoop solder Observe the basic rule of fitting: first, finish one part of the pair completely, and then fit the other around it

1. The essence and methods of cutting Cutting is an operation associated with the separation of materials into parts using a hacksaw blade, scissors and other cutting tools. Depending on the tool used, cutting can be carried out with or without chip removal.

2. TOOLS AND DEVICES USED IN CUTTING Fig. one . One-piece hacksaw machine: 1 - machine; 2 - handle; 3 - pins; 4 - hacksaw blade; 5 - head of attachment of the hacksaw blade; b - tension screw with nut Hand-held locksaw hacksaws are intended mainly for cutting high-quality and profile rolled products by hand, as well as for cutting thick sheets and strips, cutting grooves and slots in screw heads, cutting workpieces along the contour and other works.

Continuation of question 2 Fig. 2. Sliding hacksaw machine Fig. 3. Hacksaw blade: a - geometric parameters of the hacksaw blade: γ - rake angle; α is the back angle; β is the angle of sharpening; δ - cutting angle; b - wiring on the tooth; c - wiring along the canvas

Continuation of question 2 Fig. 4 . Manual scissors: a - right; b - with curved blades; c - finger hand scissors (fig. 4) are right and left. On the right scissors, the bevel on the cutting part on each of the halves is on the right side, and on the left - on the left.

Continuation of question 2 Fig. 5 . Geometric parameters of the scissors blades: a - back angle; β is the angle of sharpening; φ is the angle between the blades Fig. 6. Chair scissors

Continuation of question 2 Fig. 7. Power scissors: 1 - knife; 2 - screw; 3 - hinge link; 4 - knurled handle; 5 - handle with a plastic tip; b - axis; 7 - lever; 8 - washer Fig. eight . Desktop manual lever scissors: 1 - base; 2 - handle; 3 - knife; 4 - knife table

Continuation of question 2 Fig. 9 . Pipe cutters: a - roller: 1 - clamp; 2 - screw; 3 - screw lever; 4 - bracket; 5 - bracket; b - cutting rollers; 7 - pipe; b - clamp; в - chain; g - incisal: 1 - pressure screw; 2 - cutting tool; 3 - screw

Rules for performing work when cutting materials. Basic rules for cutting metal with a hacksaw 1. Before starting work, you must check the correct installation and tension of the blade. 2. The cutting line must be marked along the entire perimeter of the bar (strip, parts) with an allowance for subsequent processing of 1 ... 2 mm. 3. The workpiece should be firmly clamped in a vice. 4. Strip and corner material should be cut wide. 5. In the event that the length of the cut on the part exceeds the size from the blade to the frame of the hacksaw, cutting must be done with a blade fixed perpendicular to the plane of the hacksaw (hacksaw with a turned blade). 6. The sheet material should be cut directly with a hacksaw if its thickness is greater than the distance between the three teeth of the hacksaw blade. The thinner material for cutting must be clamped in a vice between the wooden blocks and cut with them.

7. The gas or water pipe must be cut and secured in the pipe clamp. When cutting thin-walled pipes, fasten in a vice, using profile wooden spacers for this. 8. When cutting, the following requirements must be observed: - at the beginning of cutting, tilt the hacksaw away from you by 10 ... 15 °; - when cutting, hold the hacksaw blade in a horizontal position; -in work, use at least three-quarters of the length of the hacksaw blade; - make working movements smoothly, without jerks, approximately 40 ... 50 double strokes per minute; - at the end of the cut, loosen the pressure on the hacksaw and support the cut part with your hand. 9.When checking the size of the cut part according to the drawing, the deviation of the cut from the marking notch should not exceed 1 mm in the larger direction.

Occupational safety rules 1. Do not cut with a blade that is too loose or too tight, as this could break the blade and injure your hands. 2. To avoid breaking the blade and injuring your hands, do not press down hard on the hacksaw when cutting. 3. Do not use a hacksaw with a loose or split handle. 4. When assembling the hacksaw, use pins that fit tightly, without swinging, into the holes of the heads. 5. If the teeth of the hacksaw blade are chipped, stop work and replace the blade with a new one. 6. To prevent the handle from jumping off and injuring the hands during the working movement of the hacksaw, do not hit the front end of the handle on the part being cut. Continuation of 3 questions

Basic rules for cutting sheet metal up to 0.7 mm thick with hand scissors 1. When marking the part to be cut out, it is necessary to provide for an allowance of up to 0.5 mm for subsequent processing. 2. Cutting should be done with sharpened scissors in gloves. 3. Place the sheet to be cut strictly perpendicular to the blades of the scissors. 4. At the end of the cut, the scissors should not be brought together completely to avoid tearing the metal. 5. It is necessary to monitor the condition of the scissors screw axis. If the scissors begin to "crush" the metal, you need to slightly tighten the screw. 6. When cutting material with a thickness of more than 0.5 mm (or when pressing the scissors handles with difficulty), one of the handles must be firmly fixed in a vice. 7. When cutting out a part of a curved shape, for example a circle, the following sequence of actions must be observed: - mark the contour of the part and cut the workpiece with a straight cut with an allowance of 5 ... 6 mm; - cut out the part according to the marking, turning the workpiece clockwise. 8. Cutting should be carried out exactly along the marking line (deviations are allowed no more than 0.5 mm). The maximum gouge in the corners should not be more than 0.5 mm. Continuation of 3 questions

Basic rules for cutting sheet and strip 1. Cutting must be done with gloves to avoid cutting your hands. 2. Cutting sheet material of considerable size (more than 0.5x0.5 m) should be done by two people (one should support the sheet and move it in the direction "away from himself" along the lower knife, the other should press the scissors lever). 3.During work, the material to be cut (sheet, strip) must be placed strictly perpendicular to the plane of the movable knife. 4. At the end of each cut, the knives should not be brought to full compression in order to avoid "tearing" of the cut material. 5. After finishing work, fix the scissor arm with the fixing pin in the lower position. Continuation of 3 questions

Basic rules for cutting pipes with a pipe cutter 1. The cutting line should be marked with chalk around the entire perimeter of the pipe. 2. The pipe must be firmly fixed in a pipe clamp or vise. Fastening the pipe in a vice must be done using profile wooden gaskets. The place of the cut should be located no further than 80 ... 100 mm from the clamping jaws or vice. 3.In the process of cutting, the following requirements must be observed: lubricate the cutting site; - monitor the perpendicularity of the pipe cutter handle to the pipe axis; -Carefully ensure that the cutting discs are located exactly, without skewing, along the cutting line; - do not apply great efforts when turning the screw of the pipe cutter handle to feed the cutting discs; - at the end of cutting, support the pipe cutter with both hands; make sure that the cut piece of pipe does not fall to your feet. Continuation of 3 questions

4. Hand power tool Fig. 10 . Mechanical hacksaw: 1 - drum; 2 - case; 3 - finger; 4 - slider; 5 - bracket; b- hacksaw blade

Continuation of question 4 Fig. eleven . Manual electro-vibration scissors: 1 - eccentric roller; 2 - the body of the cutter head; 3 - case; 4- bracket; 5 - lower knife; 6 - upper knife; 7 - lever; 8 - finger; 9 - connecting rod

5. Stationary equipment for cutting metals Fig. 12 . Stationary mechanical hacksaw: 1 - bed; 2 - table; 3 - vice; 4 - frame; 5 - trunk; 6 - branch pipe of the cooling system; 7 - electric motor; 8 - replaceable nozzles

Continuation of question 5 Fig. thirteen . Universal circular saw: 1 - electric motor; 2, 4,5,9 - handles; 3 - bracket; b - vertical column; 7- bed; 8 - cutting disc

Continuation of question 5 Fig. 14 . Pendulum saw: 1 - bed; 2 - table; 3 - cutting disc; 4 - handle; 5 - pulley; 6 - swinging trunk; 7 - bracket; 8 - support bar

Continuation of question 5 Fig. 15 . Band-saw: 1 - casing; 2 - flywheel; 3 - table; 4 - bed; 5 - cutting blade

Continuation of question 5 Fig. 16. Guillotine shears: 1 - table; 2 - hydraulic clamps; 3 - side guides; 4 - electric motor; 5 - bed; 6 - control pedal; 7 - stand

Continuation of question 5 Fig. 17. Roller shears

Continuation of question 5 Fig. eighteen . Disc shears

Continuation of question 5 Fig. nineteen . Vibrating scissors: 1 - electric motor; 2 - bracket; 3 - emphasis; 4 - the head of the staple; 5 - upper knife; 6- lower knife; 7- table; 8 - bed

5. TYPICAL DEFECTS WHEN CUTTING METAL, THE REASONS OF THEIR APPEARANCE AND METHODS OF PREVENTION Defect Cause Method of prevention Cutting with a hacksaw Skewed cut The blade is loosely tensioned. The cutting was carried out along the cross of the strip or flange of the square. Tension the blade so that it can be pressed tightly with a finger from the side. Cutting the teeth of the blade Wrong blade selection. Defective blade on - blade overheated so that two or three teeth participate in the work. Cut viscous metals (aluminum and its alloys) with blades with a finer tooth, attach thin material between wooden blocks and cut with them Blade breakage Strong pressure on the blade. Weak tension on the tray. The canvas is overstretched. Uneven movement of the hacksaw when cutting Loosen the vertical (lateral) pressure on the hacksaw, especially when working with a new or taut blade. Loosen the pressure on the hacksaw at the end of the cut. Make movements with a hacksaw smoothly, without jerking. Do not try to correct the skewed cut by skewing the knives. If the blade is dull, then it must be replaced.

Continuation of question 6 Cutting with hand scissors When cutting sheet material, the scissors crumple it. Blunt scissors. The hinge of the knives is loosened. Cut only with sharpened scissors. Before starting cutting, check and, if necessary, tighten the hinge of the scissors so that the handles move smoothly, without jamming and swinging. Tears when cutting sheet metal. converged completely, as this leads to "tears" of the metal at the end of the cut

Continuation of question 6 Defect Cause Method of prevention Deviation from the marking line when cutting with electro vibration scissors Failure to observe cutting rules When cutting large sheet material (more than 500x500 mm), rest the sheet with its trailing edge against a stop and perform cutting by moving (giving) the scissors. When cutting blanks with curvilinear contours (especially with small blank sizes), feed by moving the blank Hand injury The work was carried out without gloves.We should work with scissors only in canvas gloves (primarily on the left hand supporting the cut sheet)

Continuation of Question 6: Cutting pipes with a pipe cutter Coarse grips in the places where the pipe is fastened Violation of the rules for fastening pipes Firmly fasten the pipe in the pipe clamp so that it does not turn during the cutting process. When fixing the pipe in a vise, use wooden spacers "Ragged" end of the cut pipe Failure to follow the rules for cutting pipes Precisely position the pipe cutter discs according to the marking marks. During the cutting process, carefully monitor the perpendicularity of the pipe cutter handle to the pipe axis (under this condition, the cutting discs in the pipe do not move and the cutting line does not skew). At each turn of the pipe cutter, tighten its screw no more than half a turn. Liberally lubricate the axles of the cutting discs and the cutting points

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Developed by V.S. Serov master p / o, the highest category MDK 01.01. "Fundamentals of fitter-assembly and electrical installation work"

Lesson topic: Drilling

Purpose: the formation of knowledge and skills in the application of drilling skills Students should be able to: perform basic drilling techniques avoid defects when machining holes comply with the rules of safe work when drilling use theoretical knowledge in practice

Drilling is the formation of holes in a solid material by removing chips with a drill that makes rotational and translational movements about its axis

Drilling is used for: placing fasteners (screws, bolts, etc.) tapping internal threads improving hole quality by countersinking and reaming

Mechanized and manual drilling equipment: vertical drilling machine 2N125L desktop vertical drilling machine 2M112

Mechanized and manual drilling equipment: Radial drilling Electric drill Hand drill machine 2H55

Drilling techniques: Drilling blind holes to a given depth: A - along the sleeve stop B - along the measuring ruler

Drilling techniques: Drilling holes Drilling A- in a plane located A- an incomplete hole with an angle to another plane using an attachment plate B- on a cylindrical surface B- holes in a square B- in hollow parts

Varieties of drills: A, B- spiral, B- with straight grooves, G- perovoe, Druzheinoe, E- single-edged with an internal outlet, Zh- double-edged for deep drilling, Z- for circular drilling, I- centering

Defects when machining holes, causes of their occurrence and methods of prevention Defect Cause Method of prevention Misalignment of the hole Chip penetration under the workpiece. Incorrect linings. Clean the table and workpiece from dirt and chips. Correct or replace linings. Hole offset Drives the drill to the side. Wrong markings when drilling along markings. Check the correct sharpening of the drill. Mark the workpiece correctly. Oversized hole diameter Different length of cutting edges. Offset of the transverse cutting edge. Correctly regrind the drill Increase the depth of the hole Incorrect setting of the stop to the depth Set the stop exactly to the specified cutting depth

Safety rules when drilling Tuck hair under a headgear Carefully fasten the cuffs on the sleeves Do not: 1. Drill a loose workpiece 2. Press down firmly on the drill feed lever 3. Lean close to the drilling site to prevent chips from getting into the eyes 4. Blow off the chips

Lesson assignment Perform: drilling blind holes drilling through holes drilling a shank

Control questions# 1 What is drilling used for? № 2 What equipment is used for drilling? № 3 What drilling techniques do you know? No. 4 How to avoid defects when machining holes? № 5 What safety requirements must be observed when working with power tools for drilling?

Thank you for your attention!

The result of mastering the main professional educational program for MDK 01.01 "Basics of fitter-assembly and electrical work" are the results of the intermediate certification.

Forms of interim certification according to MDK 01.01 "Fundamentals of fitting and assembly and electrical work" is a differentiated test.

For the organization of intermediate attestation, the following has been developed: the content of the funds of assessment tools: texts of tests, a list of questions for computerized testing. Tasks for each form of interim assessment control have response standards and assessment criteria.

Forms of intermediate certification for half a year.

The main professional and general professional competencies, formed during the lessons on MDK 01.01 "Fundamentals of fitting and assembly and electrical work."

PC 1.2. Manufacturing devices for assembly and repair;

The results of the interim certification show the level of mastering professional and general professional competencies.

Indicators of the result of mastering professional and general professional competencies.

Professional competence.	Indicators for assessing the result of mastering professional competencies.
PC 1.1. Perform fitter fit and soldering of parts and assemblies of varying complexity during the assembly process;	Compliance with the algorithm of working methods when describing the technology of locksmith and locksmith - assembly work. Accuracy in determining the tool, fixtures, material required to perform locksmith and locksmith - assembly work. The accuracy of the choice of options for solving problems. Accuracy in defining concepts, formulations. Justification of the choice of solder when connecting wires of different brands by soldering; Justification of the choice of methods and the use of materials for tinning; Demonstration of knowledge of the technology of performing soldering with various solders and tinning;
PC 1.2. Manufacturing fixtures for assembly and repair	Demonstration of practical skills in making fixtures for assembly and repair Justification of the chosen device.
General professional competencies.	Indicators for assessing the result of mastering general professional competencies.
To understand the essence and social significance of your future profession, to show a steady interest in it.	Possession of the culture of thinking, the ability to generalize, analyze, perceive information, set a goal and choose ways to achieve it. Able to improve and develop his intellectual and general cultural level, to achieve moral and physical improvement of his personality
Organize your own activities, based on the goal and ways to achieve it, determined by the leader.	Rationality of planning and organization of activities for the implementation of control tasks. Timeliness of delivery of assignments, reports, etc. Argumentation of the choice of methods of control of their knowledge. Discipline, responsibility. Ability to complete the work. Self-control. Introspection.
Analyze the working situation, carry out current and final control, assessment and correction of their own activities, be responsible for the results of their work.	Demonstration of the ability to make decisions in standard and non-standard situations and take responsibility for them Responsible attitude to the results of their work Demonstration of the ability to independently learn new research methods, to change the scientific and scientific-production profile of their professional activities, to change the socio-cultural and social conditions of activity
Search for information necessary to effectively perform professional tasks.	Demonstration of skills to use normative and reference documents in the process of work
Use information and communication technologies in professional activities.	Demonstration of skills in searching for reference material on the Internet. Skills of working in professional applied programs.
Work in a team, communicate effectively with colleagues, management, clients.	Correct interaction with students, teachers;

Tasks

for the final control for the first half of the year

(differential credit)

Written test

according to MDK 01.01 Basics of fitter-assembly and electrical work

Option 1

1. Name the universal measuring instruments for dimensional control used in plumbing.

2. What is markup?

3. Name the operations performed before marking the part.

4. What operation does the locksmith perform before cutting and sawing material?

5. What is filing?

6. Name the types of drills depending on their design.

7. How is a broken drill removed from a hole in metal?

8. What tools are used to cut a helical surface on the outer cylindrical surface of the part?

9. What are the file handling requirements?

Option 2

1. What holes are used for riveting?

2. What tools, besides scrapers, are used for scraping?

3. Describe the sequence of blackening?

4. Explain the main difference between soft and hard solder.

5. What is the sequence for assembling parts and assemblies?

6. Who is allowed to service lifting and transport mechanisms, cranes and welding equipment?

7. What needs to be done just before you start assembling parts into assembly kits and subassemblies?

8. List the safety rules for grinding.

9. Name simple special dimensional inspection tools used in plumbing.

10. Describe the technology of this contact connection.

Option 3

1. Name the types of markup.

2. What is the difference between flat and spatial markings?

3. What is a marking base?

4. What should be done with the blade if the teeth are broken?

5. Name the filing tool.

6. What elements does the working part of the drill consist of?

7. What tool and when is countersinking performed?

8. Name the tool for tapping holes.

9. How to avoid accidents when filing?

10. Describe the technology of this contact connection.

Option 4

1. Name the types of riveted joints.

2. When is scraping used?

3. What is lapping?

4. What is coloring?

5. In what form is the solder produced?

6. What is machine dismantling?

7. How should the object be prepared for renovation?

8. What is a universal caliper, what is it intended for and what elements does it consist of?

9. What safety rules must be observed during metallization, tinning and soldering, as well as when gluing?

10. Describe the technology of this contact connection.

Option 5

1. What is the difference between flat and spatial markings?

2. What is kerning?

3. How can you cut pipes with a hacksaw?

4. What types are files divided into, depending on their shape?

5. What is drilling and what is it based on?

6. What is the twist drill bit?

7. Name the types of countersinks.

8. What elements does the tap consist of?

9. How should the site be prepared for refurbishment?

10. Describe the technology of this contact connection.

Option 6

1. What should be done before starting scraping?

2. Name the tools and equipment used to obtain permanent metal joints by soldering.

3. What is car repair?

4. Name the types of riveted seams.

5. Describe the specifications for riveted and bolted connections.

6. What is the compass used for

7. Name the methods of spatial marking.

8. What is the layout technique but template?

9. What safety rules should be followed when lapping and finishing surfaces?

10. Describe the technology of this contact connection.

Option 7

1. What should you do when cutting material if the cutting line is at an angle to the surface or the blade is sliding over the material?

2. How are files classified by density and size of notches?

3. Where is drilling used?

4. What determines the value of the angle at the top of the drill?

5. What is a sweep and when is it applied?

6. What is a thread profile?

7. What methods of riveting are used?

8. Name the tool and material used for scraping on paint.

9. What are the basic conditions for dismantling?

10. Describe the technology of this contact connection.

Option 8

1. Name the types of laps.

2. What is soldering?

3. What is tinning and zinc plating?

4. What is machine assembly?

5. What specifications must the axles and shafts and mounted bearings meet?

6 What is a square and in what locksmith operations is it used?

7. What do you need to markup?

8. What is marking accuracy?

9. What tool is used to saw solid materials and why?

10. Describe the technology of this contact connection.

Option 9

1 Name the types of file cuts.

2. What types of processing are used to obtain round holes in the material, depending on the required accuracy?

3. What should be done with a drill if it does not drill well?

4. Name the types and types of sweeps.

5. Name the types of threads depending on the profile.

6. Name the tool used for manual and mechanical riveting.

7. Explain the process of scraping on paint.

8. Name the materials used for lapping.

9. What safety rules should be followed when scraping?

10. Describe the technology of this contact connection.

Option 10

1. What materials, tools and fixtures are required for tinning and galvanizing parts?

2. What tool is used to remove the rolling bearing, gear wheels and pulleys from the shaft?

3. List the technical conditions for mounting the friction and gear mechanisms of the drive.

4. Name the templates frequently used by the locksmith.

5. Name the marking tool and basic tools required for marking.

6. What is the thickness of the sheet cut with different scissors?

7. How are files used depending on their shape?

8. What types of work are performed on drilling machines?

9. How should a machine or equipment be handled to ensure that it is in good working order?

10. Describe the technology of this contact connection.

Option 11

1. When are expandable and adjustable reamers used?

2. How should the threading bar be prepared?

3. What are the disadvantages and advantages of scraping?

4. What is an abrasive mineral and what is it for?

5. Name the types of soldering irons.

6. What is a bearing alloy and where is it used?

7. Name the types of repair of machinery and equipment

8. How are permanent connections disassembled?

9. What should be done before starting drilling?

10. Specify the elements of the power cable.

Option 12

1. List the technical conditions for the assembly of clutches.

2. Name the measuring accessories.

3. Name the measuring instruments for marking

4. What should be the sharpening angle of hand scissors?

5. Name the tools and accessories for drilling.

6. Name drilling defects.

7. What elements does the sweep consist of?

8. Name the reasons for defects when threading.

9. What is the importance of correct and reliable fastening of the material in a vice or fixture during filing?

10. Give the characteristics of the connection of parts

Option 13

1. Name soft solders and their melting points.

2. What is polishing?

3. What determines the choice of bearing alloys, what types of alloys are used?

4. Where is the place of work of the repairman?

5. How are parts or assembly units of detachable joints dismantled?

6. What needs to be done after assembling the machine or mechanism?

7. Name auxiliary locksmith tools and auxiliary materials.

8. What safety rules must be observed when riveting?

9. Name the tools and materials for soldering.

10. Determine the height of the head of the threaded bolt M 12 × 1.25

Option 14

1. Name auxiliary materials for marking.

2. What is called cutting and sawing metal?

3. What else, besides familiar tools and equipment, can you cut the material?

4. How should non-metallic material, artificial or non-metallic materials be fixed to avoid surface damage?

5. Name the maximum diameters of drills that can be used to drill holes in conventional types of drilling machines.

6. What is a drill jig?

7. Name the coolant used when reaming holes in various materials.

8. What is riveting?

9. What is scraping?

10. When repairing, it is necessary to cut a slot in the screws M8 × 1.25 with cylindrical head. Determine the width and depth of the slot.

Option 15

1. What is grinding?

2. Name the brazing alloys and their melting point.

3. How is the liquid bearing alloy obtained?

4. List the tools, equipment and fixtures required for the repair of machinery and equipment.

5. What should be done with the parts after disassembling them?

6. Why should the object be painted after the repair?

7. Explain the purpose and types of wrenches.

8. Name the simple measuring and measuring tools used in plumbing.

9. What operation is performed after inspection of the machine or mechanism?

10. It is necessary to drill 4 holes in the beam for M36 × 4 bolts. Determine the diameter of the holes.

Option 16

1. What should be done after flushing?

2. List the auxiliary materials used in the repair.

3. What is spray metallization and where is it used?

4. Name common means for cleaning and etching surfaces during soldering.

5. What is matting?

6. What is the purpose of grinding?

7. What tools are used for scraping?

8. Name the types of rivets depending on the shape of the head and their area of ​​application.

9. What safety requirements should be followed when working on drilling machines?

10. To lock the oil pump cover, drill holes in the bolts for cotter pins 1.8 mm. Determine the drill diameter.

Option 17

1. What is the purpose of cooling when drilling and what kind of coolants are used?

2. When is the drill ratchet used?

3. What should be the height of the vise and what should be the position of the locksmith when filing?

4. What is a pipe cutter and how to use it?

5. What is the purpose of the puller and what parts does it consist of?

6. On the basis of what is the marking of the part carried out?

7. Name the main parts that make up a hand saw.

8. What is file restoration and what is it based on?

9. What are the safety measures when cutting and sawing material?

10. Rivet two sheets 3 and 5 mm wide. Determine the diameter of the rivets.

Option 18

1. What is a drill?

2. How are holes with a diameter of more than 30 mm made in metal?

3. What is tapping?

4. What are the parts of the rivet?

5. Name the types of scrapers.

6. Name what defects may arise during grinding.

7. What is oxidation?

8. What is zinc chloride and how to use it?

9. Name the assembly views.

10. The truss is riveted with a single-row seam with steel rivets 25 mm in diameter. Determine the rivet pitch

ANSWER STANDARDS

Option 1

1. Name the universal measuring tools for dimensional control used in plumbing.

a folding metal ruler or a metal tape measure, a universal caliper, a normal caliper for external measurements, a normal internal gauge for measuring the diameter, a simple rod depth gauge, a universal goniometer, a square, compasses.

2. What is markup?

Marking is the operation of drawing lines and points on the workpiece to be processed. The outline of lines and points serves as a working boundary for processing.

3. Name the operations performed before marking the part.

cleaning the part from dirt and corrosion, degreasing the part, examining the part in order to detect defects (cracks, cavities, distortions); checking overall dimensions, as well as machining allowances; determination of the marking base; white paint coating of surfaces to be marked and drawn on them with lines and dots; determination of the axis of symmetry.

4. What operation does the locksmith perform before cutting and sawing material?

prepare the material, mark it with a scribe or mark it with nakernivanie.

5. What is filing?

Sawing is the process of removing stock with files, files or rasps. It is based on manual or mechanical removal of a thin layer of material from the treated surface.

6. Name the types of drills depending on their design.

According to the design of the cutting part, drills are divided into feather, with straight flutes, spiral with helical flutes, for deep drilling, centering and special.

7. How is a broken drill removed from a hole in metal?

A broken drill can be removed from the drilled hole by twisting it to the side opposite to the spiral of the broken part, with pliers, if there is a protruding part of the drill. If the broken drill is inside the material, then the part being drilled is heated together with the drill until it becomes red, and then gradually cooled. The released drill can be unscrewed with a special device or drilled with another drill.

8. What tools are used to cut a helical surface on the outer cylindrical surface of the part?

Round split and continuous dies, as well as four- and hexagonal plate dies, plugs for threading pipes.

9. What are the file handling requirements?

Files should be protected from moisture to prevent corrosion, and should not be thrown or placed on other files, tools or metals to prevent damage to the notch. The surface of the files is protected from the ingress of oil or grease, as well as from the ingress of dust from the grinding wheels. A new file should be used first on one side, and after dulling on the other. Personal files and velvet files should not be used for filing soft metals (tin, lead, copper, zinc, aluminum) or brass.

The file should be cleaned with a steel brush during and after work. After finishing work, they put it in a drawer or cabinet.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.

Option 2

1. What holes are used for riveting?

Riveting uses drilled, punched or punched holes.

2. What tools, besides scrapers, are used for scraping?

When scraping, cast iron plates, flat and triangular rulers, prisms, plates in the form of a rectangular parallelepiped, control rollers, and probes are used.

3. Describe the sequence of blackening?

Blackening of a steel part is carried out in the following sequence: surface polishing, degreasing with Viennese lime, rinsing, drying, coating with an etching solution. After coating with an etching solution, the part is dried at a temperature of 100 ° C for several hours, after which it is exposed to steam and hot water. Then it is cleaned wet with a wire brush.

4. Explain the main difference between soft and hard solder.

Soft solders are used for permanent joints and sealing of metals with insignificant requirements for the strength and endurance of the joint in tension and impact, brazing alloys - for permanent and sealed joints of high strength and endurance to tensile and impacts.

5. What is the sequence for assembling parts and assemblies?

The assembly sequence of parts and assemblies should be the opposite of the disassembly sequence. The assembly must be carried out in accordance with the developed technological maps assembly. Proper preparation of parts for assembly speeds up the assembly process itself and improves its quality.

6. Who is allowed to service lifting and transport mechanisms, cranes and welding equipment?

Persons with the necessary qualifications are allowed to service lifting and transport mechanisms, cranes, welding and other equipment. They must be well trained and familiar with the maintenance and operation of this type of equipment, and must also have permission to perform these types of work,

7. What needs to be done just before you start assembling parts into assembly kits and subassemblies?

make an external examination of all parts included in the assembly kit or assembly, make sure that these parts correspond to the assembled assembly or assembly unit and can be installed in the appropriate places. Before assembly, they must be thoroughly rinsed and coated with a thin layer of grease (if necessary). Before assembly, a number of parts defining appearance products must be primed and prepared for painting after assembly.

8. List the safety rules for grinding.

When grinding, it is necessary to select the correct grinding wheel, balance it and set its design speed. Attach the grinding wheel correctly and protect it with a guard. For grinding parts that are held in hands, use a stop located at a distance of 2-3 mm in front of the grinding wheel. Use shatterproof goggles when sanding. Grinding must be carried out in accordance with the instructions for the maintenance of the machine.

9. Name simple special dimensional inspection tools used in plumbing.

Simple special tools for dimensional control include: an angular ruler with a double-sided bevel, a rectangular ruler, a threaded template, a probe, a single-sided assembly plug, a double-sided limit plug, a single-sided limit clamp and a double-sided limit clamp

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 3

1. Name the types of markup.

There are two types of markings: flat and spatial.

2. What is the difference between flat and spatial markings?

3. What is a marking base?

Layout datum is a specific point, axis of symmetry or plane from which, as a rule, all dimensions on a part are measured.

4. What should be done with the blade if the teeth are broken?

interrupt sawing, remove the blade from the frame and grind the chipped teeth, after which you can use the blade further.

5. Name the filing tool.

Sawing can be done with files, files or rasps.

6. What elements does the working part of the drill consist of?

The working part of the drill consists of a guide and a cutting part.

7. What tool and when is countersinking performed?

8. Name the tool for tapping holes.

taps

9. How to avoid accidents when filing?

Pay special attention to the condition of the handle and its correct attachment to the file (the handle is inserted along the axis of the file). When attaching the handle, do not lift the file up. Files without a handle should not be used. Use especially caution when working with small files. Do not grip the end of a long file with your fingers. The material must be secured correctly and firmly.

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 4

1. Name the types of riveted joints.

Riveted connections are: overlapping, butt with one strap, butt with two straps, symmetrically, butt, with two straps, asymmetric

2. When is scraping used?

Scraping is used when it is necessary to remove traces of processing with a file or other tool, as well as when you want to obtain a high degree of accuracy and low surface roughness of machine parts connected to each other.

3. What is lapping?

Lapping is the removal of the thinnest layers of metal by means of fine-grained abrasive powders in a lubricant medium or diamond pastes applied to the surface of the tool (lapping).

4. What is coloring?

Painting is the coating of a surface with a layer of paint or varnish in order to prevent corrosion and give a part or product a presentation.

5. In what form is the solder produced?

Solder is available in the form of sheet, tape, rods, wires, meshes, blocks, foil, grains, powders and solder paste.

6. What is machine dismantling?

Dismantling is the operation of disassembling a machine or equipment into assembly units, assemblies and parts. In this case, the dismantling of the detachable

connections, and in some cases permanent connections,

7. How should the object be prepared for renovation?

Before starting the repair, the object should be cleaned of dirt, grease, if necessary - from old paint (when repairing bodies of cars, wagons, ships, etc.). Machines to be repaired or mechanisms sent for repair to specialized repair enterprises should be exempted from special types of equipment, tools and auxiliary

equipment that cannot be repaired. The transfer of the object for repair is formalized with the appropriate acceptance document, which indicates the type of necessary repair and the completeness of the equipment being handed over for repair.

8. What is a universal caliper, what is it intended for and what elements does it consist of?

The universal vernier caliper is a measuring instrument used for internal and external measurements of length, diameter and depth.

9. What safety rules must be observed during metallization, tinning and soldering, as well as when gluing?

A worker performing metallization, tinning or soldering operations comes into contact with molten metal, acids, alkalis and vapors of various caustic and harmful substances for the body. The rooms in which the above operations are performed must have good ventilation. Workers must wear protective clothing, goggles and gloves. The blowtorch must be technically sound. When pumping fuel, you cannot create high pressure, you should also not add fuel to a heated lamp. Acids and alkalis should be kept in glass bottles, and they must be diluted by adding acids to the water, and not vice versa. The workplace should be free of rags, spilled oil and grease.

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 5

1. What is the difference between flat and spatial markings?

Marking is called flat, when lines and points are drawn on a plane, spatial - when marking lines and points are applied to a geometric body of any configuration.

2. What is kerning?

Beveling is the operation of applying small dots-depressions on the surface of a part.

3. How can you cut pipes with a hacksaw?

Sawing large-diameter pipes must be done with a gradual turn of the pipe. A thin pipe should be clamped in a vise or clamping device along the radius with a slight clamping force. For sawing pipes, use a blade with fine, intact, sharp teeth.

4. What types are files divided into, depending on their shape?

locksmith flat obtuse, round, semicircular, square, triangular, flat pointed, hacksaw, oval, lens, rhombic, round wide, rasps.

5. What is drilling and what is it based on?

Drilling is the execution of a round hole in a product or material using a special cutting tool - a drill, which, during the drilling process, simultaneously has a rotational and translational movement along the axis of the hole being drilled.

6. What is the twist drill bit?

The cutting part of the twist drill consists of two cutting edges connected by a third edge - the so-called transverse bridge.

7. Name the types of countersinks.

Countersinks can be solid cylindrical, conical, shaped, welded with a welded shank, mounted solid and mounted assembled. Countersinks of small diameters are usually made solid, and large diameters - welded or mounted. Tapered countersinks have apex angles of 60 °, 75 °, 90 ° and 120 °.

8. What elements does the tap consist of?

Tap elements - working part, consisting of cutting and gauging parts and shank. The working part has a spiral cut and longitudinal grooves for chip removal. Cutting edges are created at the intersection of spiral cuts and longitudinal grooves for chip removal. The tail section ends with a square head for installation in the cartridge.

9. How should the site be prepared for refurbishment?

The place where the object is being repaired should be cleaned of dirt, metal scrap and shavings, unnecessary material and means of organizing the workplace (bedside tables, racks, roller tables, etc.). The floor must be level and clean, free from grease and oils. The approach or approach to the repair site must be free, and there must be sufficient free space around the object to be repaired so that the repairmen can move freely and place the parts and assemblies removed during dismantling from the object. The room where the repair is to be carried out must have adequate lighting, both natural and artificial sources. The room should have both general and local lighting with a voltage of 220 and 24 V. When repairing large objects, an appropriate point or first-aid kit should be provided at the repair site to provide an ambulance to a worker injured during the repair, as well as fire protection equipment (fire extinguisher, bucket, ax, hook, etc.). When repairing an object in the open air, in addition to the above measures, an awning or overlap should be provided to protect workers from atmospheric precipitation and direct sunlight, and under winter conditions, temporary insulation of the repair site should be provided.

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 6

1. What should be done before starting scraping?

check the degree of unevenness of the surface and places of unevenness to be scraped.

2. Name the tools and equipment used to obtain permanent metal joints by soldering.

with a soldering iron, in a gas flame, soldering in ovens, in a "bath" by a chemical method, autogenous soldering, etc.

3. What is car repair?

The repair of a machine is the restoration of operability, accuracy, power, speed and other parameters of the machine that determine its purpose.

4. Name the types of riveted seams.

Riveted seams are divided into longitudinal, transverse and oblique. They can be single-row, double-row and multi-row (parallel and staggered rivets). Sutures can be complete or incomplete.

5. Describe the specifications for riveted and bolted connections.

use well and correctly made parts, carefully carry out the preparatory and basic operations, use a serviceable and appropriate tool to perform these operations. Depending on the operating conditions of the part, assembly or assembly unit, the nuts in threaded connections must be installed on split washers, cotter pinned, locked, fixed with a bending washer tendril or wire twist.

6. What is the compass used for

The compass is used to draw circles, curved lines, or for sequential transfer of the position of points on the line when marking parts. Distinguish between spring compasses and with a new arc mouth.

7. Name the methods of spatial marking.

Spatial markings can be done on a scribe board using a scribe box, prisms and squares. For spatial marking, prisms are used to rotate the workpiece to be marked (Fig. 9).

8. What is the layout technique but template?

Marking using a template is used in the manufacture of a significant number of identical parts. The template is superimposed on the flat surface of the part and outlined with a scribe along the contour.

9. What safety rules should be followed when lapping and finishing surfaces?

The materials and pastes used for lapping contain, among other substances, those that are harmful and poisonous. Therefore, one should observe

general precautions (as far as possible, do not touch them with your fingers, wash your hands. Tools and machines must be in good technical condition and used in accordance with the instructions for use. Paints must be stored in fireproof boxes. When painting, spraying and polishing, fire safety measures should be taken into account. Protective clothing and a respirator should be worn by the worker, and intensive ventilation should be provided when performing these operations in confined spaces.

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 7

1. What should you do when cutting material if the cutting line is at an angle to the surface or the blade is sliding over the material?

If the cutting line has gone at an angle to the metal surface, you should interrupt cutting from this side and start on the other. To avoid slipping the blade over the material, you need to make the initial cut with a triangular file.

2. How are files classified by density and size of notches?

According to the size and density of the notches, depending on the number of notches per 10 mm of length, the files are divided into burgundy files No. 0 and I, personal No. 2 and 3 and velvet No. 4 and 5.

3. Where is drilling used?

Drilling is primarily used when making holes in parts that are joined during assembly.

4. What determines the value of the angle at the top of the drill?

The value of the angle of inclination of the helical flute of the drill depends

on the type of processed material

5. What is a sweep and when is it applied?

A reamer is a multi-edge cutting tool used to finish machining holes to produce a hole. high degree precision and with a surface of slight roughness. Reamers are subdivided into rough and finish.

6. What is a thread profile?

A thread profile is a contour obtained by cutting a helical surface with a plane passing through the axis of the screw. The thread profile consists of projections and troughs of the threads. The shaft axis is the axis of the helical surface

7. What methods of riveting are used?

Depending on the rivet diameter, needs and type of riveting, manual and mechanical riveting are used. The locking head is obtained by impact riveting and pressure riveting. Impact riveting is universal, but noisy, pressure riveting is of higher quality and noiseless.

8. Name the tool and material used for scraping on paint.

For scraping parts on paint, use a plate or ruler, as well as paint.

As a paint for scraping, a mixture of machine oil with Parisian blue or ultramarine, which has the consistency of a light paste, is used. Sometimes a mixture of engine oil and carbon black is used,

9. What are the basic conditions for dismantling?

Before proceeding with dismantling (disassembly), you need to make an external examination of the repair object or get acquainted with it on the basis of technical documentation (drawings, technical specifications, etc.). After getting acquainted with the object of repair, they begin to disassemble it. Disassembly is carried out in accordance with the sequence specified in the technical documentation (technology and drawing).

First, a machine or mechanism is disassembled into separate assembly units or units, which, in turn, are disassembled into parts. In order to comply with a certain order at workplaces during repairs, each mechanic-repairman must have a metal box of light construction or a basket, into which parts are folded in a certain order when disassembling. This method of dismantling facilitates the preservation of parts, checking their suitability, and protects against possible losses.

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 8

1. Name the types of laps.

Lapping is divided depending on the type of lapping. There are two types of lapping: lapping with an abrasive (penetrating into the lapping surface) abrasive lapping with a non-sharpening abrasive.

In accordance with the specified types of lapping, lapping are divided into manual, machine-hand, machine (mechanical) and assembly.

2. What is soldering?

Soldering is the process of creating a permanent bond between metals using an additive bonding material called brazing alloy, and the brazing alloy is brought to a liquid state during the brazing process. The melting point of the solder is significantly lower than that of the metals being joined.

3. What is tinning and zinc plating?

Tinning is the coating of the surface of metal products with a thin layer of tin or a tin-based alloy. Zinc plating is performed by cold electrolytic or hot coating of metal products with a thin layer of zinc.

4. What is machine assembly?

The assembly of a machine is the operation of connecting parts into assembly units and assemblies in such a way that, after assembly, they make up a machine that is fit for use and meets its official purpose.

5. What specifications must the axles and shafts and mounted bearings meet?

Axles and shafts must be made in accordance with the drawing. Bearing journals must be made in accordance with the established tolerance and the value of the permissible roughness indicated in the drawing, there must be no radial and axial play. Shaft-mounted rolling bearings are not

must have backlash and cracks in the clips. The alignment of the bearings must be maintained. Sleeve bearings must be designed like this

and fitted by scraping so that the bearing with its entire inner surface adheres to the journal surface, and the entire outer surface to the surface of the seat in the housing. The lubrication holes and grooves must be aligned in accordance with the drawing so that the lubricant can reliably and continuously enter the bearings.

6. What is a square and in what locksmith operations is it used?

An angle template, called a square, is used to check or draw corners on the plane of the workpiece.

Squares can be flat (regular and curved) and flat with a wide base. 90 ° square is a steel template for a right angle.

Steel elbows with an angle of 120 °, 45 ° and 60 ° are often used.

7. What do you need to markup?

For flat and spatial marking, a drawing of the part and its blanks, a marking plate, a marking tool and universal marking devices, a measuring tool and auxiliary materials are required.

8. What is marking accuracy?

Marking accuracy is the accuracy of transferring the dimensions of the drawing to the part that is being marked.

9. What tool is used to saw solid materials and why?

Solid materials are usually cut with a mechanical frame saw, band saw or circular saw. Sawing these materials by hand is very laborious and sometimes simply impossible. Mechanical sawing produces a smooth cut.

10. Describe the technology of this contact connection.

• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• The veins are cleaned to a metallic sheen.
• Aluminum conductors are overlapped, connected to their ends with a double twist or made into a ring with round-nose pliers.
• When soldering aluminum conductors, the twist is heated by the flame of a gas burner, while a solder bar is introduced into the flame.
• After heating the conductors to the melting temperature of the solder, rub the groove and the place of twisting on one side with a solder bar. As a result of friction, the oxide film is destroyed, the groove and twist are tinned and filled with solder. Similarly, the other side of the twist is soldered.

Option 9

1 Name the types of file cuts.

Files are available with single cut and double cut

A single cut can be inclined to one side, inclined at intervals, wavy, rasp. When filing soft metal surfaces

2. What types of processing are used to obtain round holes in the material, depending on the required accuracy?

Depending on the required degree of accuracy, the following types of processing are used: drilling, reaming, countersinking, reaming, boring, countersinking, centering.

3. What should be done with a drill if it does not drill well?

If the drill does not drill well, it should be sharpened. Sharpening can be done manually or mechanically. Correct sharpening of the drill makes it possible to obtain the required angles, lengthens the service life of the drill, reduces forces, and also makes it possible to obtain correct holes.

The selection of cutting angles necessary for a given material and sharpening on special sharpening machines for drills ensure that the correct sharpening angles and the position of the transverse edge in the center of the drill are obtained. After sharpening, you can check the sharpening angles using a protractor or template.

4. Name the types and types of sweeps.

There are the following types of reamers: according to the method of use - manual and machine, in shape - with a cylindrical or conical working part, in terms of machining accuracy - rough and finishing, in design - with a cylindrical shank, with a conical (Morse taper) shank and mounted. Attached reamers can be solid, with plug-in knives and floating. Manual reamers can be solid and expandable. Reamers can have simple and helical teeth.

5. Name the types of threads depending on the profile.

Depending on the profile, the threads are divided into: triangular, trapezoidal symmetrical and asymmetrical, rectangular and rounded

6. Name the tool used for manual and mechanical riveting.

For manual riveting, hammers are used to shape the rivet head, crimp, support, clamps and pliers.

For mechanical riveting, pneumatic or electric hammers, riveting tongs, supports for rivet heads, consoles are used. At large industrial enterprises, riveting machines are used - eccentric h hydraulic.

7. Explain the process of scraping on paint.

The paint is applied in a thin layer to a plate or a ruler with a brush or frequent rags, after which the plate or zhvneshsa is applied to the surface of the part intended for scraping. After several circular movements of the plate or the reciprocating movements of the ruler along the part or part on the plate, the part is carefully removed from the plate. Painted spots that appear on the part indicate irregularities protruding on the surface of the part. These irregularities are removed by scraping.

8. Name the materials used for lapping.

Lapping materials are divided into pastes, lapping powders and linen.

Diamond, white and normal electrocorundum, boron carbide, glass, polishing crocus, abrasive mineral, quicklime are used as caricatured powders. Products made of non-ferrous metals and alloys are rubbed in with non-sharpening abrasives.

9. What safety rules should be followed when scraping?

First of all, it is necessary to maintain cleanliness and order around the workplace, otherwise the employee may slip and fall, and ultimately get injured. The tool must be used with care and skill, in between work and after its completion, you need to put the tool in the box. The scraper must always be held so that the cutting edge is facing away from the worker.

The scraper must be well sharpened. When scraping, be sure to remove sharp edges from parts.

10. Describe the technology of this contact connection.

• The ends of the cores are inserted into molds (sleeves) 2 so that the joint of the cores is in the middle of the mold (for cores with ends cut at an angle of 55 °, the gap between the ends is about 2 mm). Detachable molds are fastened with bands made of soft steel wire, molds made of roofing steel - with a lock.
• The place where the veins enter the mold is sealed with a winding made of asbestos cord 7. The molds are installed horizontally to ensure complete filling with solder, protective screens 5 are put on the veins (Appendix 29). When connecting conductors with a cross-section of 120 mm2 or more, it is recommended to additionally install coolers. In this case, the length of the first step of the cable end to be cut increases from 40 to 55 mm.
• The flame of the burner 3 is used to heat the mold (sleeve) with the tinned ends of the conductors inserted into it. At the same time, a stick of solder 4 is introduced into the flame, the melt of which must fill the mold to the top. The molten solder 6 is stirred with a stirrer and slags are removed, then the heating is stopped and the solder is compacted by lightly tapping on the shape.

Option 10

1. What materials, tools and fixtures are required for tinning and galvanizing parts?

For tinning and galvanizing, depending on the part and its purpose, you need to have pure tin, zinc or their alloys, a blowtorch or a gas torch, cleaning agents necessary for degreasing and cleaning surfaces exposed to tinning or galvanizing, baths for melting tin or zinc, wiping material and pliers.

2. What tool is used to remove the rolling bearing, gear wheels and pulleys from the shaft?

Rolling bearings, gear wheels and pulleys are removed using special pullers. Pullers come in different designs, most often three-arm pullers.

3. List the technical conditions for mounting the friction and gear mechanisms of the drive.

The condition for the normal operation of the friction and gear mechanisms of the drive is the alignment of the shafts and bearings. When assembling the parts of the friction mechanisms, they must adhere to each other with their entire processed surface. Mounting of cylindrical gear wheels must be carried out in such a way that the correct meshing of the gear teeth is ensured. Correct engagement must

be ensured by the constancy of the distance between the axes of the shafts on which the gear wheels are mounted, by the strict parallelism of the axes and the arrangement of the shafts and axes in the same plane.

4. Name the templates frequently used by the locksmith.

The templates that the locksmith often use include squares, thread templates, styli, and contoured surface templates.

5. Name the marking tool and basic tools required for marking.

The marking tool includes: a scribe (with one point, with a ring, two-sided with a curved end), a marker (there are several types of them), a marking compass, center punch (ordinary, automatic, for a stencil, for a circle), calipers with a conical mandrel , hammer, center compass, rectangle, marker with a prism.

Devices for marking include: a marking plate, a marking box, marking squares and bars, a stand, a thickness gauge with a scribe, a thickness gauge with a movable scale, a centering device, a dividing head and a universal marking grip, a rotary magnetic plate, double clamps, adjustable wedges, prisms , screw props.

6. What is the thickness of the sheet cut with different scissors?

Manual shears are used for cutting sheet metal and iron sheets up to 1 mm thick, as well as for cutting wire. Sheet material up to 5 mm thick is cut with a lever shear, and material with a thickness of more than 5 mm is cut with a mechanical shear. Oil the cutting edges before cutting.

7. How are files used depending on their shape?

The shape of the files is selected depending on the configuration of the work area. Flat files are used for filing flat, curved convex and outer spherical surfaces; square files - for filing square and rectangular holes; triangular - for processing triangular surfaces, for sharpening saws, as well as for filing flat surfaces located on the floor with an acute angle; hacksaw - for filing the edges of sharp corners, as well as for making narrow grooves; rhombic - for processing very complex contours of products; round - for making semicircular and round holes, oval - for filing oval holes; semicircular and lenticular - for processing curved and concave surfaces.

8. What types of work are performed on drilling machines?

On drilling machines, you can perform the following operations: drilling, reaming to a larger diameter of a previously drilled hole, countersinking, reaming, facing, counterbiting, countersinking, tapping.

9. How should a machine or equipment be handled to ensure that it is in good working order?

In order to ensure the technical serviceability of machines and equipment, it is necessary to systematically monitor its technical condition and maintain in accordance with the instructions for operation and repair. In addition, the terms of preventive inspections and scheduled preventive repairs should be strictly observed.

10. Describe the technology of this contact connection.

• When soldering by pouring with pre-molten solder, the crucible 11 with molten solder is placed somewhat away from the soldering point so that the heat generated by it does not additionally heat the conductors and ignite the cable impregnating compound. To drain excess solder, a tray 10 is installed between the soldering point and the crucible, which is attached to the bare cores so that it does not touch the paper insulation.

Option 11

1. When are expandable and adjustable reamers used?

Expanding and adjustable reamers are used in repair work to reamer holes that have different tolerances and to minimize enlargement of an already completed hole.

2. How should the threading bar be prepared?

Before threading, the bar must be free of rust, and a grip chamfer must be removed on its end surface.

3. What are the disadvantages and advantages of scraping?

The disadvantages of scraping are too slow the processing process and significant labor intensity, which requires great precision, patience and time from the locksmith. The advantage of this type of processing is the ability to obtain high accuracy with simple tools (up to 2 microns). The advantages also include the possibility of obtaining accurate and smooth curved surfaces, processing closed surfaces and surfaces to the stop. Cast iron and steel surfaces of low hardness are well scraped. Hardened steel surfaces should be sanded.

4. What is an abrasive mineral and what is it for?

The abrasive mineral, commonly referred to as emery, is a fine-grained, dark-colored natural corundum. Abrasive mineral, in the form of loose grains or grains glued to an elastic substrate (cloth, paper), is used for polishing and lapping. The grain size is determined in the same way as with other abrasive materials. The coarser the grain, the higher the number that designates the abrasive mineral.

5. Name the types of soldering irons.

A soldering iron is a hand tool of various shapes and weights. That part of the soldering iron, which is directly soldered, is made of copper, heating the copper part of the soldering iron can be done using electricity (electricity

soldering iron), over a gas flame (gas soldering iron) or in a furnace.

For heating the soldering irons and some heating of the metals to be joined, blowtorch gasoline lamps can be used.

6. What is a bearing alloy and where is it used?

Bearing alloy is an alloy of metals (tin, lead, copper, antimony, etc.), which is used for the manufacture of casting plain bearing shells.

When the shafts rotate in bearing alloy bushings, very little friction occurs,

7. Name the types of repair of machinery and equipment

There are the following types of repairs, technical inspection, scheduled preventive (current), medium and major repairs.

8. How are permanent connections disassembled?

Machine parts or assembly units and permanent joints are disassembled using a chisel and hammer, welding equipment, a hacksaw or by riveting parts. These operations must be carried out carefully so as not to damage the surfaces of parts that will be reused in the future.

9. What should be done before starting drilling?

Before you start drilling, you need to properly prepare the material (mark and mark the drilling sites), the tool and the drilling machine. After fixing and checking the installation of the part on the table of the drilling machine or in another device, as well as after fixing the drill in the spindle of the machine, start drilling in accordance with the instructions and labor safety requirements. We must not forget about cooling the drill.

10. Specify the elements of the power cable.

1- outer cover 2- armor 3- cushion 4- sheath 5- belt insulation 6- core insulation 7- neutral core 8- conductive core

Option 12

1. List the technical conditions for the assembly of clutches.

The condition for the normal transmission of rotary motion from one shaft to another is the correct assembly of the shafts and sub-couplings at the output ends of the shafts. The shaft journals must be firmly seated in the bearing seats, and there must be no beating. The shafts must be aligned and the half-couplings must be in balance.

2. Name the measuring accessories.

Auxiliary measuring devices include: plates, rulers, prisms, measuring rolling pins, sine rulers, levels, measuring posts and wedges for measuring holes

3. Name the measuring instruments for marking

Measuring tools for marking are:

ruler with graduations, vernier gauge, thickness gauge with a movable scale, vernier caliper, square, goniometer, caliper, level, control ruler for surfaces, dipstick and reference tiles.

4. What should be the sharpening angle of hand scissors?

The angle of sharpening of the cutting parts of the scissors depends on the nature and grade of the cut metal and material. The smaller this angle, the easier it is for the shears to cut into the material and vice versa. However, at a low angle of taper, the cutting edges quickly chip out. Therefore, in practice, the sharpening angle is chosen in the range of 75-85 °. Dull edges of the scissors are sharpened on a grinding machine. The correctness of sharpening and wiring between the edges is checked by cutting the paper.

5. Name the tools and accessories for drilling.

To perform the drilling operation, drills with a tapered or cylindrical shank, tapered adapter sleeves, wedges for knocking out are used

drills, self-centering drill chucks, two- and three-jaw, handles for fixing drills in chucks, keyless chucks, spring chucks with automatic drill shut-off, machine vices, boxes, prisms, clamps, squares, manual vices, inclined tables, as well as various types of devices, manual and mechanical drilling machines and drills.

6. Name drilling defects.

Defects in the drilling process are different: it can be a breakdown of the drill, chipping of cutting edges, deviation of the drill from the axis of the hole, etc.

7. What elements does the sweep consist of?

The reamer has the following elements: a working part, a neck and a shank (tapered or cylindrical).

8. Name the reasons for defects when threading.

Reasons for defects in threading are as follows: inconsistency between the diameters of the holes or shafts to be cut, damage to the tool, threading without lubrication, blunt tools, poor fastening or poor setting of the tool, as well as inability to cut threads

9. What is the importance of correct and reliable fastening of the material in a vice or fixture during filing?

Correct and reliable clamping of the material in a vice or a device ensures accurate material processing, minimal worker effort and labor safety.

10. Give the characteristics of the connection of parts

Detachable fixed connection.

Option 13

1. Name soft solders and their melting points.

Soft solders are tin-lead (with or without antimony). The melting temperature of these solders is from 183 to 305 ° C.

2. What is polishing?

Polishing is a finishing treatment in which surface irregularities are smoothed mainly as a result of their plastic deformation and, to a lesser extent, as a result of cutting off the microroughness protrusions.

Polishing is used to make the surface of the part shine. As a result of polishing, the surface roughness is reduced and a mirror-like shine is achieved. The main purpose of polishing is decorative surface treatment, as well as a decrease in the coefficient of friction, an increase in corrosion resistance and fatigue strength.

3. What determines the choice of bearing alloys, what types of alloys are used?

The selection of the bearing alloys most suitable for these conditions is carried out, taking into account their physical and mechanical properties, in particular antifriction properties, the ability to withstand certain pressures and temperatures, hardness, toughness, casting qualities, etc. The properties of a bearing alloy are determined by its main component. There are bearing alloys on tin, lead, aluminum, cadmium, zinc, copper (bronze, brass) and other "bases. Bearing alloys based on tin, lead or copper are most often used.

4. Where is the place of work of the repairman?

The place of work of the repair locksmith is located at the object that needs to be repaired (near a machine, equipment, mechanism, etc.).

5. How are parts or assembly units of detachable joints dismantled?

Dismantling and disassembly of parts and assembly units of detachable joints are carried out using all kinds of keys, drifts, various types and designs of pullers, as well as other tools. The disassembly of screw connections can be facilitated by lubricating the threaded parts with kerosene, oil, or by heating the nuts for a short time.

6. What needs to be done after assembling the machine or mechanism?

After assembling the machine or mechanism, you need to inspect them. The purpose of the inspection is to control the correctness of the assembly, eliminate any deficiencies noticed, check the filling with oil or grease of power transmissions of various mechanisms, remove from the assembled machine or mechanism the remaining forgotten tool, various parts and auxiliary materials.

7. Name auxiliary locksmith tools and auxiliary materials.

Auxiliary locksmith tools and auxiliary materials are: a hand brush, a metal brush for cleaning files, a marking tool, cleaning materials, chalk, vise cheek pads, wooden pads, oils and greases, markeoastal - digital and letter, wood rasp, fixer knife, wooden hammer, rubber hammer, emery cloth, brushes, spoon for melting tin, crucible for melting fusible alloys of non-ferrous metals, oil and insulating tape, red lead, paints.

8. What safety rules must be observed when riveting?

For riveting, first of all, you need to use a serviceable tool. Wear gloves on your hands, protect your eyes with glasses. The rivet head should be correctly positioned in the support or console, and the swage should be correctly positioned on the rivet body. During riveting, do not touch the crimp with your hand.

9. Name the tools and materials for soldering.

Soldering requires soldering irons, materials called solders, and agents that cleanse, etch, and prevent surface oxidation during soldering.

10. Determine the height of the head of the threaded bolt M 12 × 1.25

h = 0.7 × 12 = 8.4mm

Option 14

1. Name auxiliary materials for marking.

Auxiliary materials for marking include:

chalk, white paint (a mixture of chalk diluted in water with linseed oil and the addition of a composition that prevents the oil from drying), red paint (a mixture of shellac with alcohol, adding a dye), lubricant, detergents and etching

materials, wooden blocks and slats, small tinware for paints and a brush.

2. What is called cutting and sawing metal?

Cutting is the operation of dividing a material (object) into two separate parts using hand shears, chisels or special mechanical shears.

Sawing is the operation of separating a material (object) using a hand or power hacksaw or circular saw.

3. What else, besides familiar tools and equipment, can you cut the material?

In addition to the tools and equipment known to us, an oxygen-acetylene flame can be used to cut the material, while cutting is performed using a special torch.

4. How should non-metallic material, artificial or non-metallic materials be fixed to avoid surface damage?

In order to avoid damage to the surface of products or materials fixed in a vice, pads should be used. Pads made of soft metals (copper, zinc, lead, aluminum, brass), wood, plastics, felt, cleaning material or rubber are applied to the cheeks of the vice. The product or material is inserted between the pads and then secured.

5. Name the maximum diameters of drills that can be used to drill holes in conventional types of drilling machines.

On vertical drilling machines (depending on the type), holes can be drilled with drills up to 75 mm in diameter, on bench drilling flocks - with drills up to 15 mm in diameter, on table-top drilling machines -

drills up to 6 mm in diameter. Hand-held electric drilling drills (depending on the type) can drill holes up to 25 mm in diameter, hand-held pneumatic drilling machines - drills up to 6 mm in diameter.

6. What is a drill jig?

A drilling jig is a tool with a jig plate for processing a large number of identical parts with the same position

holes without preliminary marking. Locksmith conductors can be of different designs. They can be installed on the part and attached directly to the part, they can be a device with a jig plate, into which the part is installed and clamped. In this case, there are appropriately spaced holes in the jig plate with jig bushings inserted into them with a certain hole diameter, through which the drill is guided into the part clamped in the drilling device. In some cases, jig plates have holes without jig bushings.

7. Name the coolant used when reaming holes in various materials.

Coolant is used to cool the tool, reduce friction, and increase tool life.

8. What is riveting?

Riveting is the operation of permanently connecting materials using rods called rivets. The rivet, ending with a head, is installed in the hole of the materials to be joined. The part of the rivet protruding from the hole is riveted in a cold or hot state, forming a second head.

9. What is scraping?

Scraping is the process of obtaining the accuracy of shapes, dimensions and relative position of surfaces required according to the conditions of work to ensure a snug fit or tightness of the joint. When scraping, thin chips are cut from uneven surfaces that have already been previously processed by cutting processes with a file or other cutting tool.

10. When repairing, it is necessary to cut a slot in the screws M8 × 1.25 with cylindrical head. Determine the width and depth of the slot.

h = 0.2 × 8 = 1.6 mm

Option 15

1. What is grinding?

Grinding is the processing of parts and tools using rotating abrasive or diamond grinding wheels, based on the removal of a very thin layer of material from the surface of a very thin layer of material in the form of tiny chips.

2. Name the brazing alloys and their melting point.

The hardness of the solder is determined by the grade and chemical composition of the metals used for the solder. They are divided into solders based on copper, brass, silver, nickel and aluminum. In addition, a distinction is made between heat-resistant and stainless brazing alloys based on nickel, manganese, silver, gold, palladium, cobalt and iron. The melting temperature of brazing alloys ranges from 600 to 1450 ° C.

3. How is the liquid bearing alloy obtained?

Liquid bearing alloy is produced in a graphite or cast iron crucible. The crucible is heated with a blowtorch, on a forge or with a flame of gas burners. The casting temperature of bearing alloys based on tin or lead is from 450 to 600 ° C. The melting temperature of bronze is from 940 to 1090 ° C. Before casting, crushed charcoal is poured onto the molten bearing alloy, which protects the alloy from oxidation.

4. List the tools, equipment and fixtures required for the repair of machinery and equipment.

However, the following tool is common for any type of repair: locksmith - hammers, permanent and sliding keys, chisels, files, hacksaws, screwdrivers, punch, various kinds of pullers, scrapers; universal measuring - rulers, calipers, etc.; electric and pneumatic - drills, wrenches, etc. When repairing equipment, you may need blowtorches and a tool for soldering. In some cases, during the repair, you may need equipment for gas or electric welding and cutting, riveting tools, devices for bending, crimping and expanding pipes,

as well as vibrating machines for cutting metal. In all cases, workbenches with a vice are needed for the work of repairmen. When repairing heavy and large machines, lifting equipment is used for objects (tripods with hoists, winches, self-propelled or stationary cranes, electric or forklift trucks, trolleys or other types of lifting and transport vehicles).

5. What should be done with the parts after disassembling them?

After disassembly, the parts should be degreased and rinsed thoroughly. For this purpose, kerosene is used, as well as special alkaline or other compounds and chemical solutions. Parts are washed in special tanks or baths, using brushes or compressed air. In specialized repair shops or at sites, in some cases, special washing machines are used with a supply of washing liquid under pressure. After rinsing the parts in a detergent solution, they should be rinsed again in hot water and dried in a stream of warm air. Rinse the parts with care in protective clothing and goggles.

6. Why should the object be painted after the repair?

In the process of repairing an object, its outer surfaces or individual parts may lose their presentation, their corrosion resistance may decrease. To protect the repaired machine or mechanism from corrosion and give them a presentation after repair and testing, they are painted, and the parts that cannot be painted are subjected to special treatment to give them corrosion resistance.

7. Explain the purpose and types of wrenches.

The wrenches are used to tighten and unscrew nuts and bolts, and also to hold the bolt when tightening the nuts. There are two types of wrenches: non-adjustable and adjustable universal.

Non-adjustable wrenches have a constant jaw size for the hexagon of a nut or bolt, universal adjustable wrenches have a wrench jaw opening that is variable within certain limits.

Non-adjustable wrenches are divided into flat one-way and two-way overhead one-way straight and two-way curved straight and curved end and hook

8. Name the simple marking and measuring tools used in plumbing work.

Simple marking and measuring tools used in plumbing work are:

hammer, scribe, marker, center punch, square, compass, marking plate, ruler with divisions, vernier caliper and caliper.

9. What operation is performed after inspection of the machine or mechanism?

After inspecting and checking the readiness of the machine or mechanism for operation, you should start checking the object at idle speed, while observing the labor protection and safety rules. After checking the machine or mechanism at idle speed, re-inspect both the entire machine and its individual units and the most critical parts. Defects identified during inspection must be eliminated.

10. It is necessary to drill 4 holes in the beam for M36 × 4 bolts. Determine the diameter of the holes.

d = 1, × 36 = 36.9 mm

Option 16

1. What should be done after flushing?

The cleaned, washed and dried part must be checked to ensure that it meets the requirements of the drawing. Checking and evaluating the technical condition of the part will show

whether it can be reused in the car. For this purpose, an external examination of the part should be carried out, its dimensions should be checked, and it should also be established whether

the actual dimensions of the surfaces of the part within the tolerances in which this detail can work. The check is carried out, as a rule, using a universal measuring tool.

2. List the auxiliary materials used in the repair.

The auxiliary materials used in the repair include cleaning and detergents (kerosene, alkaline solutions, detergents, etc.), oils, rags, wood, asbestos, gasoline, coolants, zinc chloride, paints, felt, rubber, additives for soldering, red lead, lubricants, coke, coal, petroleum jelly, chalk, hydrochloric acid, etc.

3. What is spray metallization and where is it used?

Spray plating is the application of a metal coating to the surface of a product by spraying molten metal under pressure.

This operation is performed using special pistols. Metallization is used to protect products from corrosion, as well as to repair worn-out machine parts, to correct defective castings, as well as to correct defects resulting from cutting.

4. Name common means for cleaning and etching surfaces during soldering.

Chemical cleaning and etching agents include: hydrochloric acid, zinc chloride, borax, boric acid, ammonia. The surface can be cleaned with power tools, an abrasive material or file, or wire brushes. During brazing, the surface is protected from oxidation by means such as stearin, turpentine and rosin.

5. What is matting?

Matting is giving a matte ash-gray color to a metal surface. This operation is performed mechanically on small forged, cast, sawed or cast parts using steel or copper wire brushes that rotate. Before starting matting, moisten the metal surface with soap solutions.

6. What is the purpose of grinding?

The aim of grinding is to obtain surfaces of parts with low roughness and very precise dimensions.

7. What tools are used for scraping?

Scraping is done with tools called scrapers.

8. Name the types of rivets depending on the shape of the head and their area of ​​application.

To make riveted connections, the following types of rivets are used, with a semicircular head, with a countersunk head, with a half-countersunk head, tubular,

explosive, split, pan head, flat head, tapered head, tapered head and preparation, oval head.

9. What safety requirements should be followed when working on drilling machines?

The drilling machine must be switched on and operated in accordance with the instructions for use of the equipment, as well as in accordance with the requirements of labor safety. Special work clothes should be used, hair must be matched to the headgear, especially for women. The parts must be correctly and securely fastened in a vice or fixture that has good technical condition... When drilling small holes, the left

the hand holding the part must resist the opposite of the direction of rotation of the spindle. During the working stroke of the drilling machine spindle, do not hold or brake the spindle, change speeds and feeds, clean the table or workpiece from chips. The drill needs to be cooled with coolant using a brush or watering. Cooling with damp rags or rags is not allowed. The drilling machine must be switched on or off with dry hands.

10. To lock the oil pump cover, drill holes in the bolts for cotter pins 1.8 mm. Determine the drill diameter.

The drill diameter should be 2 mm.

Option 17

1. What is the purpose of cooling when drilling and what kind of coolants are used?

The cutting fluid (coolant) has three main functions: it is a lubricant to reduce friction between the cutting tool, drill, metal of the part and chips; is a cooling medium that intensively removes heat generated in the cutting zone and facilitates the removal of chips from this zone.

Coolant is used in all types of metal cutting.

Good cutting fluid does not corrode tools, accessories and parts, does not have a harmful effect on human skin, does not have an unpleasant odor and removes heat well.

2. When is the drill ratchet used?

Drilling ratchets are used to drill holes in hard-to-reach places in steel structures. The manual drive, provided by the oscillating movement of the ratchet arm, rotates the drill and feeds it along the axis of the hole. The disadvantage of drilling with a ratchet is low productivity and high labor intensity of the process.

3. What should be the height of the vise and what should be the position of the locksmith when filing?

The height of the installation is of great importance for the correct processing of the product, the productivity and well-being of the locksmith.

Select the height of the vise in accordance with the height of the worker. In practice, they choose this height, resting their elbows on the cheeks of the vice (the fist when vertically

the position of the hand should reach the chin of an erect worker). If the vise is installed below this position, then put gaskets, and if the height of the vise is high, then the gaskets are removed, or a stand or ladder is placed under the locksmith's feet. The vise worker should be in such a position that the feet are at an angle of 45 ° to each other,

moreover, the left leg should be put forward at a distance of 25-30 cm from the axis of the right foot. The axis of the left foot in relation to the working axis of the file should be at an angle of about 30 °. This situation guarantees

productive and safe work of the locksmith and reduces his fatigue.

4. What is a pipe cutter and how to use it?

Pipe cutter is a tool for cutting pipes. Pipe cutters are of different types; one-, two- and three-knife, as well as chain.

In the pipe cutter, the role of the cutting part is played by a roller, the edges of which are sharpened. The three-knife pipe cutter consists of a cheek in which there are two roller blades, a holder in which one roller is installed, handles and levers. A pipe cutter is applied to a pipe fixed in a vice or a gripping device and tightened to the stop with the help of a handle. Oscillatory or rotational

the movement of the lever and the gradual convergence of the knives-rollers cut the pipe. An even and clean cut line of the pipe can be obtained with a chain cutter.

5. What is the purpose of the puller and what parts does it consist of?

A puller is a locksmith's tool for removing gears, couplings, pulleys, bearings, levers, etc. from shafts. from hex head or square head screw or handle.

6. On the basis of what is the marking of the part carried out?

The flat or spatial marking of the part is carried out on the basis of the drawing.

7. Name the main parts that make up a hand saw.

A manual hacksaw consists of a fixed or adjustable frame, a handle, a hacksaw blade. The canvas is fixed in the frame with two steel pins, a bolt and a wing nut. A bolt with a nut serves for tension

framed canvases

8. What is file restoration and what is it based on?

Restoration of files is the restoration of its cutting ability after its wear by removing dull teeth and applying a new notch to it. Restoration is carried out by annealing it, grinding off the old notch and making a new one (manually or mechanically), followed by quenching again. The file can be restored several times, but each time it becomes thinner and more prone to cracking.

9. What are the safety measures when cutting and sawing material?

For safety reasons, the instrument should be checked first. Then you need to correctly and securely fix the material in a vice or fixtures, as well as correctly and firmly seat the frame saw handle. Hazardous areas near the power scissors are covered with a cover or shields. The mechanical shears are operated according to the operating instructions by a specially trained worker.

10. Rivet two sheets 3 and 5 mm wide. Determine the diameter of the rivets.

d = √2 × (3 + 5) = 4 mm

Option 18

1. What is a drill?

A drill is a cutting tool that makes cylindrical holes

2. How are holes with a diameter of more than 30 mm made in metal?

To get holes with a diameter above 30 mm in metal or a part, double drilling should be used. The first operation is performed with a drill with a diameter

10-12 mm, and then - with a drill of the required diameter (reaming). When drilling with two reamers or drilling, reaming and countersinking, cutting forces and operating times are significantly reduced.

3. What is tapping?

Threading is the formation of a helical surface on the outer or inner cylindrical or tapered surfaces of a part.

4. What are the parts of the rivet?

A rivet consists of a head and a cylindrical shank called the rivet body. The part of the rivet protruding from the other side of the material to be joined and intended to form the closing head is called the leg.

5. Name the types of scrapers.

Distinguish between manual and mechanical scrapers, and they can be flat one-sided and two-sided, solid and with inserted plates, triangular solid and triangular one-sided, semicircular one-sided and double-sided, spoon-shaped and universal

6. Name what defects may arise during grinding.

As a result of the wrong choice of depth and feed, negligence in the approach of the grinding wheel to the part (or vice versa, the part to the wheel), damage and even rupture of the grinding wheel or part can occur, and burns can also appear, indicating structural changes in the surface of the material. Cooling is mandatory when sanding. A soda solution is used as a cooling liquid.

7. What is oxidation?

Oxidation is a blue or dark blue oxide layer on the surface of a steel part or product. The most common method of oxidation in plumbing work is based on coating a well-cleaned object from rust with a thin layer of linseed oil and heating it in a furnace on a hot coke.

8. What is zinc chloride and how to use it?

Zinc chloride is a chemical compound of hydrochloric acid with zinc. It is obtained by placing pieces of zinc in dilute hydrochloric acid.

After the end of the reaction (hydrogen ceases to evolve), zinc chloride should be poured into another dish, leaving the sediment in the previous dish, and the liquid for cleaning or etching metals is ready. You need to dilute the acid by adding water to it, and not vice versa.

9. Name the assembly views.

A distinction is made between assemblies based on complete interchangeability, partial interchangeability, selective selection of parts, fitting, and assembly with adjustment.

10. The truss is riveted with a single-row seam with steel rivets 25 mm in diameter. Determine the rivet pitch

CRITERIA FOR EVALUATION

The control task for each option contains 10 questions.

Each question is worth 10 points. (Total 100 points).

If the answer to the question is, in fact, correct, but there are insignificant flaws, or the answer is incomplete, it is estimated at 7 points.

0.7 - 0.8 70 - 80 3 beats

0.81 - 0.9 81 - 90 4 chorus

0, 91 - 1.0 91 - 100 5 ex.

1. What kind of work is called plumbing? What kind of work is called fitting and assembly? Give examples.

Locksmith work is a cold cutting of metals, carried out by hand (file, hacksaw, marking, metal cutting, etc.), or mechanized (hand press, electric drill, etc.) method.

ASSEMBLY WORKS is a production process, as a result of which raw materials and semi-finished products are transformed into finished products.
2. What is called a part, assembly, mechanism, machine? Give examples. Which of these items can be called an "assembly"?

A DETAIL is a product made of a material that is homogeneous in name and brand.

ASSEMBLY is a product that is obtained by connecting individual elements together. An assembly can be made up of single parts or parts and smaller assemblies.
MACHINE - a device that performs mechanical movements in order to transform energy, materials or information

MECHANISM is the internal structure of a machine that drives it

NODES are a collection of jointly working parts, which are separate units, united by one purpose.
3. What is a technological process? operation? Transition? Reception? Give examples.

A TECHNOLOGICAL PROCESS is an ordered sequence of interrelated actions that are performed from the moment the initial data appears until the required result is obtained.

The assembly technological process is divided into operations, transitions and receptions.

ASSEMBLY OPERATION is a complete part of the assembly process performed during the manufacture of a product at a separate workplace by one or more workers. An operation can consist of a series of transitions, which are characterized by the consistency of the tool used.

RECEPTION is the name of the part of the transition, consisting of a number of the simplest working movements performed by one worker.
4. Name and characterize the types of assembly according to the form of organization and the relative arrangement of workplaces. Give examples.

There are two BASIC ORGANIZATIONAL FORMS OF ASSEMBLY: stationary and mobile.

STATIONARY ASSEMBLY is carried out at a stationary workplace, to which all the necessary parts, materials and smaller assembly units are supplied, the assembly of which can be carried out at separate workplaces (according to the principle of dismemberment of operations), which reduces the process time.
MOBILE ASSEMBLY is performed only on the principle of dismemberment of operations. During the assembly process, the product moves from one workplace to another. Workplaces are equipped with the necessary tools and devices. This type of assembly allows assemblers to specialize in certain operations and increase labor productivity.
DEPENDING ON THE LOCATION OF WORKPLACES relative to each other, the assembly is FLUSHED AND INCLUSIVE.

With a mobile in-line assembly, workplaces are located in the sequence of performing the operations of the assembly process, and the whole process is divided into separate operations that are approximately equal or multiple of the execution time. Assembled items leave the production line at regular intervals called a takt. In-line assembly can be carried out both with a movable and with a stationary collected object.
In the production of large products, in-line assembly is used on fixed stands, in which a worker or a team of workers perform the same operation, moving from one stand to another. After the last operation is completed, the finished product is removed from each stand.

5. What is workplace? What is called a workplace organization? What are the basic requirements for organizing a locksmith's workplace (before, during and after work).

A WORKPLACE is an area equipped with the necessary technical means, in which the work activity of the performer or a group of performers is performed, jointly performing one work or operation.

WORKPLACE ORGANIZATION is a system of measures for equipping a workplace with tools and objects of labor and their placement in a certain order.

BASIC REQUIREMENTS FOR A WORKPLACE ORGANIZATION:

• 
  The most comfortable (normal) reach is determined by the semi-

an arc with a radius of about 350 mm for each arm (the inclination of the body when working while standing should be at an angle of no more than 30 ° in the maximum reach of 550 mm)

• 
  Competent arrangement of tools, fixtures, etc.
• 
  At the end of the work, cleaning the workplace

6. Define the concepts of "equipment", "fixtures", "tools" for locksmith and fitter-assembly work? Give examples.

Locksmith equipment is a complex of various devices that are used for the correct and efficient organization of workplaces. For example, a locksmith's workbench.

DEVICE is a structure, device, mechanism, device, etc., designed to perform a certain work, certain actions. For example, a screw clamp (clamp).

Locksmith tools is a collection of tools designed for manual processing of such materials.
7. How is the quality control of locksmith and fitter-assembly works carried out? Name the controls used, give examples .

Quality control of assembly and fitting and assembly work is carried out visually, as well as using various devices (for example, a bench square, a probe) or tools (for example, a ruler, vernier caliper).
8. Plane marking: definition, purpose, technology of implementation with detailed operational description.

MARKING – this is the operation of drawing lines (scratches) on the workpiece, defining, according to the drawing, the contours of the part and the places to be processed.

Markup:

• 
  planar
• 
  spatial.

Plane marking is used when the contours of the part lie in the same plane; for spatial marking, lines are applied in several planes or on several surfaces.

Marking technology:

1. 
   study of documentation
2. 
   preparation of the workpiece surface for marking

• 
  cleaning (with sandpaper)
• 
  if necessary, coating with special solutions (for untreated surfaces of castings made of ferrous and non-ferrous metals - chalk diluted in water to the state of milk, and 50 g of wood glue per 1 liter of water (the glue is diluted separately, then it is boiled with chalk; for treated steel surfaces and cast iron - copper sulfate (2-3 teaspoons per glass of hot water) or rubbing the wetted surface with powder of copper sulfate. Non-ferrous and steel rolled products, as well as precious metals do not paint, as the marking lines are clearly visible. In some cases, for a clearer application of the drawing, the marking lines are painted with white watercolor paint).
• 
  nakernivanie (core, hammer) and drawing (scribe, ruler).

If it is necessary to make not one, but several identical parts, then they are used to mark them sample- flat sample piece. The template is tightly pressed against the workpiece by hand or with a clamp (Fig. 67) and traced around the contour with a scribe.

• 
  Control (self-control) of the markup quality (square, ruler)

9. Cutting metals: definition, purpose, technology of execution with detailed operational description

CUTTING - locksmith's operation performed when notching, cutting and cutting into parts of metal and various hard materials (textolite, getinax, etc.).

In repair practice, cutting operations are performed:

Hand scissors consist of two halves connected by a screw.

Each half of the scissors is one piece: a knife and a handle.

The industry makes right and left scissors. For the right scissors, the upper cutting edge of the blade is located to the right of the lower blade, and for the left, it is on the left side.

N
Figures a and b show the correct grip of the scissors, depending on the conditions of the technological operation.

R
cutting with a hacksaw

The hacksaw blade must be fixed in the machine so that it is not too tight or too loose, the teeth of the hacksaw blade must be directed "away from you", that is, in the direction of the forward movement of the hacksaw.

V During cutting, the hacksaw should be kept in a horizontal position; the normal stroke length of the hacksaw should be such that at least 2/3 of the length of its blade is involved in the work.

Cutting of parts with straight edges from sheets up to 40 mm thick, as a rule, is carried out on guillotine shears .

The sheet to be cut is inserted between the lower and upper knives until it stops and clamped with a clamp. The upper knife, pressing on the sheet, produces chipping.

10. Cutting of metals: definition, purpose, technology of execution with detailed operational description

A CUT is a locksmith operation, during which a layer of metal is removed from the workpiece or workpiece with the help of a cutting and percussion tool, or the metal is cut into pieces.

The felling is one of the rough locksmith operations with an accuracy of about, 5 - 1 mm.

AND
cutting tools

CHISEL

TO ANAVOCHNIK

TO REITZMESSEL

P
RIEMES OF CUTTING

Before starting work, it is necessary to set the height of the vise, fix it firmly and take the correct position. The workpiece should protrude 3-5cm
T
THE ECHNOLOGY OF THE CUTTING

1
1. Metal filing: definition, purpose, technology of execution with detailed operational description

SAWING is the removal of a metal layer from the surface of a workpiece to be processed by means of a special cutting tool - a file.

Filing:

• 
  preliminary (draft)
• 
  final (finishing and finishing)

FILE CLASSIFICATION (by purpose)

• 
  Dresser files - used for rough processing of a metal surface.
• 
  Personal files - Suitable for fine finishing and a clean, jagged surface.
• 
  Velvet - used for finishing metal.

FILE CLASSIFICATION (by form)

1. 
   Round file - processing round, oval and concave surfaces;
2. 
   Semicircular files - has two sides, flat and round, processes planes with one side, concave and semicircular surfaces with the other;
3. 
   Triangular files - treatment of surfaces and holes inaccessible to flat files;
4. 
   Square files - processing of narrow, straight surfaces inaccessible to flat files;
5. 
   Flat files with oval ribs - used for processing various types of rounding.

P RIEMAS OF METAL SAWING

During operation, the file makes reciprocating movements: forward - working stroke, backward - idle. In the course of the working stroke, the tool is pressed against the workpiece, during the idle stroke, it is carried out without pressure. The tool must be moved strictly in the horizontal plane. The pressure applied to the tool depends on the position of the file. At the beginning of the working stroke, the left hand is pressed slightly harder than the right. When the middle part of the file is brought into the workpiece, the pressure on the tip and the handle of the tool should be approximately the same. At the end of the working stroke, the right hand is pressed harder than the left.

There are several ways of filing: transverse, longitudinal, cross and circular. Transverse filing (Fig a) is performed when removing large allowances. With longitudinal filing of workpieces (Fig. B), the straightness of the processed surface is ensured. It is better to combine these two methods of filing: first, filing is performed across, and then along. When filing with a cross stroke (Fig. C), good self-control over the course and quality of work is ensured. First, filing with an oblique stroke from left to right, then, without interrupting work, with a straight stroke and finish filing again with an oblique stroke, but already from right to left. Circular filing (Fig. D) is performed in cases where frequent irregularities need to be removed from the treated surface.

P
When filing planes located at right angles, first file one of the surfaces clean, and then process the second surface at right angles to the first. Sawing of surfaces along the inner right angle is carried out so that the edge of the file, on which there is no notch, faces the second surface.

The correctness of filing is checked with a ruler or square for the lumen (see figure): if there is no lumen, the surface is flat. The durability of the files depends a lot on their care.

From prolonged use, the notch of the file is chipped and erased, as a result of which the tool loses its cutting ability. To prolong the service life of the file, rub it with chalk, which protects the notch from clogging with small chips. If the cut of the file is still clogged with sawdust, it must be cleaned with a steel brush.

12. Bending and straightening of metals: definition, purpose, technology of execution with detailed operational description.

G
Metal bending is the effect of pressure on the metal to give the required shape.

As a result of this action, one part of the metal workpiece is bent relative to the other at the required angle. For good results, you need to apply proper pressure to the metal. It is very important that the metal workpiece does not lose its strength during the bending process. To maintain strength, only plastic deformation should be applied to the metal, which does not transform into metal rupture.

For bending at right angles, it is convenient to use a vice (the thicker the metal, the more massive the vice should be, so as not to break them). The workpiece is clamped in a vice between the squares-mouthpieces along the marking line and is bent towards the fixed jaw by hammer blows.

If it is required to bend sheet metal of small thickness (up to 1 mm), then in a home workshop, along with a vice, additional devices are used. In this case, it is also desirable to clamp the sheet material on both sides. To avoid dents when bending relatively thin sheets, it is recommended to use not an ordinary metal hammer, but mallet.

E
If you need to bend large sheets, then use the simple frames shown in the figure.

The corner is attached to the front edge of the workbench. The metal sheet is placed on the workbench in such a way that the line of the intended bend is exactly above the edge of the workbench, where the frame is fixed. Next, press the sheet from above with a hand and bend a sheet of metal with a mallet, evenly striking successively along the bending line.

The middle frame has a square section and is also used for a number of techniques, including metal bending.

The last round frame is designed to produce rounded bends. It is often used to make pipes from thin sheets of iron.

Straightening is a plumbing operation that is used to eliminate mechanical defects in a workpiece.

It is possible to straighten small parts using an anvil and a hammer (sledgehammer). If you need to straighten thin sheets of metal or soft parts made of non-ferrous metals, hammers made of soft material are used, respectively: copper, brass, wood. Sheets and plates are driven by hammer blows on convex places, turning the sheet over if necessary.

Editing thin sheets is a more complicated operation: when hitting convex places, the bulge will bend in the opposite direction and stretch even more. The point of the operation here is to stretch out the edges of the sheet, thereby restoring the plane. Therefore, the blows are mainly applied to the edges of the sheet. The blows are needed light but frequent. Good results require straightening practice and an understanding of the mechanics of the sheet metal straightening and bending process.

After finishing editing and in the process, check the evenness of the part by eye or with a ruler (for more accurate checks, a marking plate is needed).
13. Making holes: definition, purpose, technology of execution with detailed operational descriptions (including finishing of holes).

DRILLING is one of the types of making and machining holes by cutting using a special tool - a drill.

The twist drill consists of a working part, a shank and a neck. The working part of the drill, in turn, consists of a cylindrical (guide) and cutting parts.

The shank is intended for fixing the drill in the drill chuck or machine spindle and can be cylindrical or conical in shape. The tapered shank has a foot at the "end, which serves as a stop when pushing the drill out of

The drill neck, connecting the working part with the shank, serves to exit the abrasive wheel during the grinding of the drill during its manufacture. On the neck, the brand of the drill is usually indicated.

On the guide part there are two helical grooves, along which the chips are removed during the cutting process.

Drilling is a necessary operation for making holes in various materials during their processing, the purpose of which is:

• 
  Making holes for tapping, countersinking, reaming or boring.
• 
  Making holes (technological) for placing electrical cables, anchor bolts, fasteners, etc.
• 
  Separation (cutting) of blanks from sheets of material.

Drilling operations are performed on machine tools and manual equipment:

• 
  Mechanical drills: drilling using human muscle strength.
• 
  Electric drills: drilling on installation with a portable power tool (including impact drilling).
• 
  Perforators

Drilling technology:

Study of documentation, preparation of the necessary materials and tools

Preparation of the workpiece surface for processing

Markup

Drilling

Checking the quality of drilling

Countersinking is the processing of the top of the holes in order to obtain chamfers or cylindrical recesses, for example, for a countersunk screw or rivet head.

COUNTER-SINKING is the treatment of holes received; by casting, stamping or drilling, to give them a cylindrical shape, improve the accuracy and quality of the surface.

REAMING is the finishing of holes. In essence, it is similar to countersinking, but provides higher accuracy and low roughness of the surface of the holes.

14. What is a part? Classify parts by purpose, give examples.

Parts are the simplest elements, each of which is made without the use of assembly.

Parts are combined into units, units into mechanisms, mechanisms into machines.

Part classification

By appointment

• 
  Fasteners: nut, washer, bolt, screw, screw, nail, rivet, etc.
• 
  Transmission: shaft, key, pulley, belt, sprocket, gear, etc.
• 
  Housing: beds, instrument cases, covers, casings
• 
  Rotations: axes, shafts
• 
  Elastic elements: springs

An axle is a part designed only to support rotating parts (do not transmit torque, only work in bending)

Shafts are parts that not only support rotating parts, but also transmit torques (they work in bending and torsion)

Body parts are parts that enclose the mechanisms of machines, support the mechanisms, are the basis for the relative position of the main units, form the outline of the machine or its individual units

P ruzhka - an elastic element designed to accumulate and absorb mechanical energy By the type of perceived load:

• 
  compression springs
• 
  extension springs
• 
  torsion springs
• 
  bending springs

P stretching ruins- designed to increase in length under load. In the unloaded state, they usually have closed turns. There are hooks or rings at the ends to secure the spring to the structure.
Compression Springs- designed to reduce length under load. Coils of such springs do not touch each other without load. The end turns are pressed against the adjacent ones and the ends of the spring are ground. Long compression springs are placed on mandrels or glasses to avoid loss of stability.
15. Name and describe the main technological, economic and operational requirements for assemblies (machines and mechanisms).

Technological requirements:

• 
  TECHNOLOGY - manufacturing of a product with minimal labor, time and money, in full compliance with its purpose.

Economic requirements:

• 
  ECONOMY - the minimum cost of production and operation of power plants.

Operational requirements:

• 
  RELIABILITY in accordance with GOST 27.002–89 is the property of an object to preserve in time within the established limits the values ​​of all parameters characterizing the ability to perform the required functions in specified modes and conditions of use, maintenance, repairs, storage and transportation
• 
  RELIABILITY - the ability to maintain their performance indicators for a given operating time without forced interruptions.
• 
  FAILURE - a phenomenon associated with partial or complete loss of the product's performance.
• 
  DURABILITY (RESOURCE) - the ability to maintain the specified indicators to the limit state with the necessary breaks for repairs and maintenance.
• 
  REPAIRABILITY - the suitability of the product for the prevention, detection and elimination of failures and malfunctions through maintenance and repair.
• 
  STORAGE - the ability to maintain the required performance after a specified period of storage and transportation.

16. Classify the connections of parts in electrical installations by the nature of the connection. Give examples for each species

Connections of parts in EI are:

Detachable

One-piece

Detachable connections are those that can be disassembled without destroying the parts or elements that hold them together.

For example, threaded connections.

Non-detachable connections are those that cannot be disassembled without destroying the parts or elements that hold them together.

For example, welded, brazed, glued, riveted.
17. What connection is called a threaded connection? What is a thread, name the types of thread and its characteristics. Describe the technology for making a threaded connection (with a detailed operational description).

THREADED CONNECTION, connection of parts by means of a thread.

THREAD - a surface formed by a helical movement of a flat contour along a cylindrical or conical surface.

Threads are classified according to the following characteristics

L
EVA THREAD - formed by a contour rotating counterclockwise and moving along an axis in the direction away from the observer.

RIGHT THREAD - formed by a contour rotating clockwise and moving along the axis in the direction from the observer.

THREAD PARAMETERS

• 
  A thread profile is a thread contour in a plane passing through its axis.
• 
  Profile angle - the angle between the sides of the profile.
• 
  The thread pitch P is the distance between adjacent side sides of the same name in the direction parallel to the thread axis.
• 
  The thread run Рh is the distance between the closest side sides of the same name, belonging to the same helical surface, in a direction parallel to the thread axis. The thread stroke is the value of the relative axial movement of the screw (nut) per revolution.
• 
  Outside thread diameter (d - for a bolt, D - for a nut) - the diameter of an imaginary cylinder described around the tops of the external thread or the valleys of the internal thread.
• 
  Internal thread diameter (d1 - for a bolt, - for a nut) - the diameter of an imaginary cylinder inscribed in the valleys of the external thread or in the tops of the internal thread.
• 
  The average thread diameter (d2 - for a bolt, D2 - for a nut) is the diameter of an imaginary coaxial cylinder with a thread that intersects the threads in such a way that the width of the thread protrusion and the width of the groove (groove) are equal.

Thread marking

Read from left to right

• 
  Letter (s) - thread type

M - metric (triangular)

MK - metric conical

G - pipe

Tr - trapezoidal

S-persistent

• 
  The number after the letter (s) is the thread diameter (in mm)
• 
  The number after the dash is the thread pitch (in mm)
• 
  Letters after thread pitch - thread type (by screwing method)

- left (right is not indicated)

• 
  Fractional alphanumeric designation - thread fit: in the numerator - the tolerance field of the internal thread, in the denominator - the role of the tolerance of the external thread.

For instance:

M12 x 1 - 6H / 6g

M - metric (triangular) thread

Outer thread diameter - 12 mm

Thread pitch - 1mm

Thread landing - 6H / 6g

The technology for making a threaded connection (for example, a bolt-nut connection):

• 
  alignment of the connected elements to establish the tolerance of the holes
• 
  install the bolt
• 
  washer installation (if necessary)
• 
  nut installation

18.What is welding? Name the types of welding, give examples of their use in power plant. Describe the technology for performing one of the types of welding (with a detailed operational description).

Welding is a technological process of obtaining a permanent connection by establishing interatomic and intermolecular bonds between the parts to be welded during their heating (local or general) and / or plastic deformation.

Types of welding:

• 
  thermal class (fusion welding using thermal energy): arc, electric arc, plasma, laser
• 
  thermomechanical class (types of welding carried out using thermal energy and pressure): contact, diffusion, forging, friction
• 
  mechanical class (types of welding carried out using mechanical energy and pressure): explosion, ultrasonic, cold

X Cold welding is, in principle, a method of forming permanent press joints.

Cold welding occurs due to the plastic deformation of the metals being welded in the butt zone under the influence of mechanical force.

Before welding, the surfaces to be welded are cleaned of contamination by degreasing, processing with a rotating wire brush, scraping. When butt welding the wires only cut the ends. After that, the parts to be joined are placed between the clamps and squeezed using punches.

19. What is soldering? What is solder, flux? Give examples. Describe the technology for performing one of the types of soldering (with a detailed operational description).

SOLDERING is a technological operation used to obtain a permanent connection of parts from various materials by introducing between these parts a molten material (solder) having a lower melting point than the material (materials) of the parts to be joined.

SOLDER is a metal or alloy, the melting point of which is much lower than that of the products being joined.

Depending on the melting point, the following types of solders are distinguished:

• 
  soft (low-melting) - melting point no more than 450 ° С
• 
  hard (medium-melting) - 450-600 ° С
• 
  high-temperature (high-melting) - over 600 ° C.

SOLDER MARKING

POS40 - tin-lead solder with a tin content of 40%

POSK 2-18 - tin-lead solder with a tin content of 2%, a cadmium content of -18%, the remaining 80% is lead.

The numbers at the end of the marking may indicate the melting temperature of the solder

#, Ni63 W Cr Fe Si B 970-1105

FLUX is a substance that cleans surfaces and solder from oxides and impurities and prevents the formation of oxides, as well as increases the flow of molten solder.

TYPES OF FLUXES

1. 
   Non-corrosive (protective) soldering fluxes only have a protective effect. Due to their low activity, they are unable to dissolve the oxide film of most metals and can be used mainly for brazing copper and its alloys, as well as steel products coated with silver, copper, tin or cadmium. Such fluxes include rosin and its solutions in alcohol or organic solvents, as well as wood resins, wax, stearin, petroleum jelly. With the use of protective fluxes, only low-melting solders can be soldered.
2. 
   Weakly corrosive soldering fluxes are more active than non-corrosive ones and consist of animal fats, mineral oils, organic acids (lactic, citric, oleic, stearic, benzene, oxalic and others), their solutions in water or alcohol or in derivatives of organic acids and bases (amine hydrohalides, chlorides and fluorides). To weaken the corrosive action, rosin or other non-corrosive components are added to them. Weakly corrosive fluxes easily evaporate, burn or decompose when heated. They are used for soldering with low-melting solders.
3. 
   Corrosive soldering fluxes are composed of inorganic acids, metal chlorides and fluorides. They are used in the form of aqueous solutions in solid and pasty state. Corrosive fluxes are capable of destroying resistant oxide films of ferrous and non-ferrous metals. These fluxes are effective in any method of soldering most metals.

Rosin (colophon resin) is a fragile, glassy, ​​amorphous substance from dark red to light yellow in color. It is part of the resins of coniferous trees and is obtained from the resin (resinous substance (turpentine) released when coniferous trees are injured) after the extraction of crushed wood with organic solvents or the distillation of crude tall oil.

SOLDERING TECHNOLOGY:

1. 
   Reasonable choice of materials, tools, fixtures
2. 
   Preparation of elements to be brazed for brazing
3. 
   Soldering
4. 
   Checking the quality of soldering

20. What is bonding? Name the types of adhesives, give examples of their use in ET. Describe the gluing technology (with a detailed operational description).

GLUING is the operation of permanently joining elements made of homogeneous or heterogeneous materials using glue.

In many of the requirements for adhesives in the electrical industry, they are comparable to structural adhesives used in other industries. Additional requirements take into account the possibility of not only mechanical destruction of the system, but also a violation of its electrical conductivity. The operating temperature of modern electrical equipment often precludes the use of almost all thermoplastic resins as the base of adhesives, replacing them usually with adhesives based on thermosetting resins.

Adhesives used in electrical equipment must have the following properties (all or only some): good electrical characteristics, for example, low volume resistance and low dielectric constant; chemical resistance; moisture resistance; non-toxic; non-susceptibility to the formation of traces on the surface under the influence of leakage currents and resistance to radiation.

Adhesives are used in the production of electrical equipment of the following types: transformers, switch parts, capacitors, microwave devices, motors, generators and insulators. Adhesives are also used, for example, when assembling belt drives (for connecting the ends of a belt).

Fitting and assembly work... Connection types

All types of connections of parts used in fitting and assembly work are divided into two main groups: detachable and one-piece. Detachable connections are those that can be disassembled into their component parts. This group includes threaded, keyed, spline, pin and wedge connections. One-piece, respectively, those connections, the disassembly of which is possible only when the fastening or the parts themselves are destroyed. This group includes press, riveted, welded and glued joints.

Assembly of threaded connections

When trying to disassemble any mechanism or locksmith's structure, be it the engine of a washing machine or an object of plumbing equipment, you will notice that most of all connections of parts are precisely threaded. And this is no coincidence: threaded connections are simple, reliable, interchangeable, and convenient to adjust.

The assembly process of any threaded connection includes the following operations: installation of parts, baiting, screwing, tightening, sometimes tightening, if necessary, installing locking parts and devices that prevent self-loosening.

When baiting, the screwed-in part must be brought to the threaded hole until the axes coincide and screwed into the thread by 2-3 threads. Anyone who has worked with small screws knows how inconvenient it can be to hold a screw in hard-to-reach places, for example, from below. Professionals in such cases use magnetic and other special screwdrivers. But if they are not there, you should not despair and curse the stubborn screw with strong words, the problem can be solved with the help of a simple device that is easily made in just a few seconds. Make a small hook from a thin soft wire and support the screw with it until it fits into the threaded hole for several threads. Then you just need to pull on the wire - the loop will open and release the screw for further screwing in with the tool.

After baiting, an assembly tool (wrench or screwdriver) is installed on the part and rotational movements are imparted to it (screwed). The screwing is completed with a tightening, which creates an immobility of the connection.

Tightening is performed when the part is fastened with several bolts (screws). For example, when attaching the cylinder head (in a car engine), the bolts are screwed in without preliminary tightening, and after they are all installed, they are tightened. This is done in a specific order - the so-called spiral method (Fig. 50).

Rice. 50. Diagram of a possible sequence of tightening (tightening) of bolts (screws, nuts).

Threaded connections in mechanisms that are exposed to pulsating loads (vibration) during operation are often unscrewed themselves, which can cause an accident. Therefore, when assembling such mechanisms, they resort to locking the threaded connections.

The simplest, rather reliable and does not require any special fixtures method of locking is locking with a locknut. It is screwed on after tightening the main fastening nut and tightened until it fully contacts its end. The locking mechanism with this method is based on an increase in the friction surfaces in the threads and on the surfaces of the nuts.

Locking with lock washers is also widespread (fig. 51).

Rice. 51. Methods for locking threaded connections: a - a lock washer; b - cork; c - wire; d - welding or beading.

Such a washer has either a spout, which is bent to the edge of the nut after tightening it, or a tab, which is inserted into a specially drilled hole in the body of the part. Open-headed screws (bolts) can be secured with wire. Holes in the heads of the screws (bolts) for the wire in this case are drilled before installing them in the assembly. The wire should be inserted into the holes in such a way that the tension on its ends creates a screwing torque.

Stopping by welding or punching, in fact, turns a detachable connection into a permanent one.

Quite often, studs are used in threaded connections, which, unlike a bolt or screw, do not have a head. In order to ensure a tight fit of the stud in the body of the part, you can use one of the proposed methods: the stud tension is formed due to thread runaway (see the chapter on cutting external threads) or is provided by a tight thread with an interference fit along the average diameter of the turns. If the body of the part is made of a material less durable than the hairpin, then a spiral insert made of steel wire of rhombic cross-section is used: it is inserted into the thread of the body of the part before the stud is screwed in. This method not only increases the strength and wear resistance of the joint (due to an increase in the thread cut surface in the body part), but also contributes to a tight fit of the stud. To form a sealed, watertight connection, a gasket made of an easily deformable material (copper-asbestos, paronite, etc.) is placed between the parts to be connected.

In some cases, it is required to obtain a connection of special strength, which cannot be achieved using conventional bolts made of low-grade metal, since they simply break under large transverse loads. It is expensive to buy special high-strength bolts, and you will not always find them in stores. In such cases, it is possible to apply a layer of epoxy resin to the surfaces of the parts that will be in contact before assembly. The connection will turn out to be very strong even with the use of ordinary cheap bolts.

Assembly of keyway and spline connections

Another type of fixed detachable connections are key-spline, which are formed by rods - keys. Keyed connections are mainly used in torque transmission mechanisms. Depending on the load on such connections and the operating conditions of the mechanism, wedge, prismatic and segment keys are used (Fig. 52).

Rice. 52. Varieties of keyway connections: a - wedge key.

Rice. 52 (continued). Varieties of keyway connections: b - parallel key; in - a segmented key; g - splined; d - pin.

Rice. 52 (continued). Varieties of keyway connections: e - correctly assembled connection; g - defect of the increased clearance; h - defect from misalignment of the axis of the keyway.

Typically, this connection consists of a shaft, key and wheel or bushing.

A type of keyed connections is splined, when the key is integral with the shaft. Due to the fact that not three, but two parts are involved in this connection, the connection is more accurate.

When assembling key connections, a pin can be used instead of a key. The pin connection is more technologically advanced (which is ensured by the interchangeability of parts), but requires additional processing: in the female part and on the shaft, it is necessary to jointly drill and reamer a hole for the pin with a tapered reamer.

The sequence for assembling the keyed connection is as follows: the shaft is fixed in a vice, a key is installed in the shaft groove and a covering part is put on. In this case, the connection of the key with the shaft must be tight (the key is installed in the groove of the shaft with an interference fit), while the key is installed more freely in the groove of the hub.

When mounting the female part (wheels, bushings, etc.) on the shaft, it is necessary to ensure that the axes of the shaft and part coincide. An incorrect keyway will deform and break the key. The main reason for this defect is an increased clearance or misalignment of the axis of the keyway. In order to avoid defects in the joints, the groove is fitted by scraping, and the dimensions of the grooves and keys are adjusted and the misalignments of the axes are controlled.

Soldered connections. Tinning

Soldering allows you to combine elements from different metals and alloys with different physical and mechanical properties into a single product. For example, the soldering method can be used to join low-carbon and high-carbon steels, cast iron parts with steel, hard alloy with steel, etc. Particularly noteworthy is the possibility of soldering parts made of aluminum and its alloys. The method of soldering carbide plates to holders is widely used in the manufacture of cutting tools.

In a home workshop, soldering is the most accessible form of the formation of fixed permanent joints. When brazing, a molten filler metal called solder is introduced into the gap between heated parts. Solder, which has a lower melting point than the metals being joined, wetting the surface of the parts, joins them during cooling and solidification. In the process of soldering, the base metal and the solder, mutually dissolving in each other, provide a high joint strength, which is the same (with high-quality soldering) with the strength of the whole section of the main part.

The soldering process differs from welding in that the edges of the parts to be joined do not melt, but only heat up to the melting temperature of the solder.

To make soldered connections, you need: an electric or indirectly heated soldering iron, a blowtorch, solder, flux.

The power of an electric soldering iron depends on the size of the parts to be joined, on the material from which they are made. So, for soldering copper products of small sizes (for example, wire with a cross section of several square millimeters), a power of 50-100 W is sufficient, when soldering electronic devices, the power of an electric soldering iron should be no more than 40 W, and the supply voltage should be no more than 40 V, for soldering large parts require a power of several hundred watts.

The blowtorch is used to heat the indirectly heated soldering iron and to warm up the parts to be soldered (with a large soldering area). Instead of a blowtorch, you can use a gas torch - it is more efficient and reliable in operation.

Tin-lead alloys with a melting temperature of 180–280 ° C are most often used as solder. If bismuth, gallium, cadmium are added to such solders, then low-melting solders with a melting temperature of 70–150 ° C are obtained. These solders are relevant for soldering semiconductor devices. In cermet brazing, a powder mixture is used as a solder, consisting of a refractory base (filler) and low-melting components, which provide wetting of the filler particles and the surfaces to be joined. Alloys are also commercially available in the form of bars or wires, which are a symbiosis of solder and flux.

The use of fluxes in the soldering process is based on their ability to prevent the formation of an oxide film on the surfaces of parts when heated. They also reduce the surface tension of the solder. Fluxes must meet the following requirements: maintaining a stable chemical composition and activity in the range of melting temperatures of the solder (that is, the flux should not decompose into components under the influence of these temperatures), the absence of chemical interaction with the metal and solder being brazed, ease of removing the products of interaction between the flux and the oxide film ( flushing or evaporation), high fluidity. Soldering of various metals is characterized by the use of a certain flux: when brazing parts made of brass, silver, copper and iron, zinc chloride is used as a flux; lead and tin require stearic acid; sulfuric acid is suitable for zinc. But there are also so-called universal solders: rosin and soldering acid.

Parts that are supposed to be connected by soldering should be properly prepared: cleaned of dirt, remove with a file or sandpaper the oxide film formed on the metal under the influence of air, pickle with acid (steel - hydrochloric, from copper and its alloys - sulfuric, alloys with a large nickel content - nitrogen), degrease with a swab dipped in gasoline, and only then proceed directly to the soldering process.

The soldering iron needs to be heated. Heating is checked by immersing the tip of the soldering iron in ammonia (solid): if the ammonia hisses and blue smoke emanates from it, then the heating of the soldering iron is sufficient; under no circumstances should the soldering iron be overheated. If necessary, its nose should be cleaned with a file from the scale formed during heating, immerse the working part of the soldering iron in the flux, and then in the solder so that droplets of molten solder remain on the tip of the soldering iron, warm the surfaces of the parts with a soldering iron and irradiate them (that is, cover with a thin layer molten solder). After the parts have cooled down a little, connect them tightly together; reheat the soldering point with a soldering iron and fill the gap between the edges of the parts with molten solder.

If it is necessary to connect large surfaces by soldering, then they act a little differently: after heating and tinning the soldering point, the gap between the surfaces of the parts is filled with pieces of cold solder and at the same time the parts are heated and the solder is melted. In this case, it is recommended to periodically process the tip of the soldering iron and the soldering point with flux.

The fact that the soldering iron is unacceptable to overheat has already been said, but why? The fact is that an overheated soldering iron does not hold the droplets of molten solder well, but this is not the main thing. At very high temperatures, the solder can oxidize and the joint becomes weak. And when soldering semiconductor devices, overheating of the soldering iron can lead to their electrical breakdown, and the devices will fail (this is why soft solders are used when soldering electronic devices and the effect of a heated soldering iron on the soldering point is limited to 3-5 seconds).

When the adhesion site has completely cooled down, it is cleaned of flux residues. If the seam is convex, then it can be leveled (for example, with a file).

The quality of the soldering is checked: by visual inspection - for the detection of unsoldered places, by bending at the junction - the formation of cracks is not allowed (test for strength); the brazed vessels are checked for tightness by filling with water - there should be no leaks.

There are soldering methods in which hard solder is used - copper-zinc plates with a thickness of 0.5–0.7 mm, or rods with a diameter of 1–1.2 mm, or a mixture of sawdust of copper-zinc solder with borax in a ratio of 1: 2. Soldering iron in this case it is not used.

The first two methods are based on the use of flake or bar solder. Preparing parts for hard soldering is similar to preparing for soft soldering.

Next, pieces of solder are applied to the place of the solder and the parts to be soldered together with the solder are twisted with a thin knitting steel or nichrome wire (with a diameter of 0.5–0.6 mm). The place of soldering is sprinkled with brown and heated until it melts. If the solder has not melted, then the place of soldering is sprinkled with brown a second time (without removing the first portion) and heats up until the solder melts, which fills the gap between the parts to be soldered.

In the second method, the place of soldering is heated red-hot (without pieces of solder), sprinkled with borax and a solder bar is brought to it (continuing heating): the solder melts and fills the gap between the parts.

Another soldering method is based on the use of a powder mixture as a solder: the prepared parts are heated red-hot at the soldering point (without solder), sprinkled with a mixture of borax and solder sawdust and continue to heat until the mixture melts.

After soldering by any of the three proposed methods, the soldered parts are cooled and the place of soldering is cleaned from the remains of borax, solder and knitting wire. The quality of soldering is checked visually: to detect unsoldered places and strength, lightly tap the soldered parts on a massive object - with poor-quality soldering, a kink is formed in the seam.

The types of soldered joints are shown in Fig. 53.

Rice. 53. Designs of soldered joints: a - overlapping; b - with two overlaps; in - end-to-end; g - oblique seam; d - end-to-end with two overlaps; e - in Tavr.

In most cases, the parts are tinned first, which facilitates subsequent soldering. A schematic of the tinning process is shown in Fig. 54.

Rice. 54. Scheme of tinning with a soldering iron: 1 - soldering iron; 2 - base metal; 3 - zone of fusion of the solder with the base metal; 4 - flux; 5 - surface layer of the flux; 6 - dissolved oxide; 7 - flux vapors; 8 - solder.

However, tinning can be used not only as one of the stages of soldering, but also as an independent operation, when the entire surface of a metal product is covered with a thin layer of tin to give it decorative and additional performance characteristics.

In this case, the coating material is not called solder, but half. Most often they are tinned with tin, but in order to save money, lead can be added at half a day (no more than three parts of lead per five parts of tin). The addition of 5% bismuth or nickel halfway gives the tinned surfaces a beautiful shine. And the introduction of the same amount of iron at half-day makes it more durable.

Kitchen utensils (utensils) can only be tinned with pure pewter, adding various metals to it is dangerous to health!

The half-shell fits well and firmly only on perfectly clean and degreased surfaces, therefore, before tinning, the product must be thoroughly cleaned mechanically (with a file, scraper, sandpaper to a uniform metallic luster) or chemically - hold the product in a boiling 10% caustic soda solution for 1-2 minutes, and then pickle the surface with 25% hydrochloric acid solution. At the end of cleaning (regardless of the method), the surfaces are washed with water and dried.

The tinning process itself can be carried out by rubbing, dipping or electroplating (with such tinning, it is necessary to use special equipment, therefore, as a rule, galvanic tinning at home is not carried out).

The grinding method is as follows: the prepared surface is covered with a solution of zinc chloride, sprinkled with ammonia powder and heated to the melting point of tin.

Then you should apply a tin bar to the surface of the product, distribute the tin over the surface and grind it with clean tow until an even layer is formed. Re-siphon off unfinished places. Work should be done with tarpaulin gloves.

In the dip tinning method, the tin is melted in a crucible, the prepared part is grasped with tongs or pliers, immersed for 1 minute in a solution of zinc chloride, and then for 3-5 minutes in molten tin. The part is removed from the tin and the excess half-day is removed by vigorous shaking. After tinning, the product should be cooled and rinsed with water.

Welding works

To create fixed permanent joints, welding is also widely used, by means of which an interatomic bond is established between the parts to be joined.

Depending on the form of energy used in the formation of a welded joint, all types of welding are divided into three classes: thermal, thermomechanical and mechanical (Table 1).

Table 1. Classification of types of welding

Of course, not all types of welding can be done in a home workshop. Most of them require sophisticated equipment. Therefore, we will consider in more detail those types of welding that are most accessible to the home craftsman.

But first, about the preparation of parts that are intended to be joined by welding: oily places must be washed with a solution of caustic soda, and then with warm water, the welding places should be processed with a file and an organic solvent, the edges should be sawed or milled to form a chamfer.

Most often, gas welding is used in domestic conditions (Fig. 55, a). The principle of gas welding is as follows: gas (acetylene), burning in the atmosphere, forms a beam of flame, which melts the filler material - wire or bar. The molten bar fills the gap between the edges of the parts, resulting in a weld. Gas welding can weld both metals and plastics.

Rice. 55. Types of welding: a - gas: 1 - filler material; 2 - welding torch; b - electric arc welding with a consumable electrode: 1 - consumable electrode; 2 - electrode holder; c - electric arc welding with a non-consumable electrode: 1 - electrode holder; 2 - non-consumable electrode, 3 - filler material; d - diagram of explosion welding: 1, 2 - plates to be welded; 3 - explosive charge; 4 - electric detonator.

Electric arc welding is also widespread (Fig. 55 b, c). It can be produced both with a consumable electrode and a non-consumable one - carbon or tungsten (in this case, a filler material is additionally introduced into the melting arc zone).

Medium, high carbon and alloy steels are classified as metals with limited weldability. To avoid cracks when welding parts made of these materials, they are preheated to a temperature of 250-300 ° C. Sheet steel parts up to 3 mm thick can be gas welded.

Explosion welding is shown in Fig. 55, d: one of the plates to be welded is fixedly installed on the base, a second plate is placed above it at a height h, on which the explosive charge is placed. The charge is exploded with an electric detonator, as a result of which a detonation wave, having a high speed and high pressure, imparts the collision speed to the second plate. At the moment of contact of the plates, they are welded.

It is difficult to carry out other types of welding at home (devices for diffusion, laser, electron-beam and other types of welding are not as widely available as welding machines for arc or gas).

Assembling riveted joints

If the assembly unit (joint unit) will be subjected to high dynamic loads during operation and the soldering method is not applicable due to the fact that the parts are made of metals with poor weldability, then riveted joints are used in these cases.

The rivet is a metal rod of circular cross-section, with a head at the end, which is called a mortgage, and is semicircular, countersunk and semi-countersunk in shape (Fig. 56).

Rice. 56. Types of rivets: a - with a countersunk head; b - with a semicircular head; c - with a flat head; d - with a half-countersunk head; e - explosive rivet: 1 - recess filled with explosive.

The rivet is drilled with a drill having a diameter greater than the diameter of the rivet shank. The dimensions of the rivets depend on the thickness of the riveted parts.

The riveting operation itself is preceded by the preparation of parts for the implementation of this type of connection. First, you need to mark the riveted seam: if the riveting is overlapped, then the upper part is marked, for butt riveting, an overlay is marked.

In this case, it is necessary to observe the distance between the rivets and the distance from the center of the rivet to the edge of the part. So, for a single-row rivet t = 3d, a = 1.5d, for a double-row rivet t = 4d, a = 1.5d, where t is the step between the rivets, a is the distance from the rivet center to the edge of the part, d is the rivet diameter.

Next, you should drill and cross holes for rivet rods. When selecting the diameter of the drill, it should be taken into account that for rivets with a diameter of up to 6 mm, a gap of 0.2 mm must be left, with a rivet diameter of 6 to 10 mm, the gap should be 0.25 mm, from 10 to 18 mm - 0.3 mm. When drilling holes, it is necessary to strictly observe the angle between the axis of the hole and the planes of the parts of 90 °.

With the direct method, blows are applied from the side of the closing head, and for good contact between the riveted parts, their tight compression is necessary. In the reverse method, blows are applied from the side of the insert head, and a tight connection of the parts is achieved simultaneously with the formation of a closing head.

Riveting is carried out in the following sequence (Fig. 57):

- rivet rods are selected with a diameter depending on the thickness of the riveted sheets:

where d is the required diameter, s is the thickness of the riveted sheets. The length of the rivets should be equal to the total thickness of the riveted parts plus the allowance for the formation of the closing head (for countersunk - 0.8–1.2 rivet diameter, for semicircular - 1.25–1.5);

- rivets are inserted into the extreme holes of the riveting seam and the embedded heads are supported on a flat support, if the heads are to be countersunk, or on spherical, if the heads are to be semicircular;

- upset the parts in the place of riveting until they fit tightly;

- upsetting the rod of one of the extreme rivets with a hammer striker and flattening it with the hammer nose;

- further, if the head is to be flat, then it is leveled with a hammer; if it is semicircular, then the lateral blows of the hammer give it a semicircular shape and, with the help of a spherical crimp, achieve the final shape of the closing head;

- the second extreme rivet is riveted in the same way, and then all the others.

Rice. 57. The sequence of the hand forging process: a - rivets with countersunk heads.

Rice. 57 (continued). The sequence of the manual riveting process: b - rivets with semicircular heads.

The connection of parts (mainly thin) in hard-to-reach places is made with explosive rivets with an explosive in the recess (Fig. 56, e). To form a connection, the rivet is put in place in a cold state, and then the insert head is heated by a special electric heater for 1-3 seconds to 130 ° C, which leads to an explosion of the explosive filling the rivet. In this case, the closing head gets a barrel-shaped shape, and its expanded part tightly pulls together the riveted sheets. This method is highly efficient and good quality riveting.

It is necessary to insert explosive rivets into the holes by smooth pressing, without impacts. Do not remove varnish, unload rivets, bring them near fire or hot parts.

For manual riveting, a square hammer is often used. To ensure a good connection, the weight of the hammer must match the diameter of the rivets. For example, with a rivet diameter of 3-4 mm, the weight of the hammer should be 200-400 g, and with a diameter of 10 mm - 1 kg.

If the diameter of the drill for making a hole for rivets, the diameter and length of the rivet itself is incorrectly selected, if other conditions of the operation are violated, the riveted joints may have errors (Table 2).

Table 2. Defect in riveted joints and its causes

If a defect is found in riveted joints, incorrectly supplied rivets are cut down or drilled out and riveted again.

Riveting is greatly facilitated by pneumatic riveting hammers with air spool valves. With low compressed air consumption, they offer high performance.

Gluing

Gluing of parts is the last type of assembly of fixed permanent joints, in which a layer of a special substance is introduced between the surfaces of the parts of the assembly unit, capable of immovably holding them together - glue.

This type of connection has a number of advantages: firstly, the possibility of obtaining assembly units from dissimilar metals and non-metallic materials; secondly, the gluing process does not require elevated temperatures (such as welding or soldering), therefore, deformation of parts is excluded; thirdly, the internal stress of the materials is eliminated.

In fitting and assembly work, adhesives are usually used: EDP, BF-2, 88N (Table 3).

Table 3. Brand of glue and its scope

Like all other types of joints, the quality of glued joints largely depends on the correct preparation of surfaces for the bonding process: they should not be stained with dirt, rust, traces of grease or oil. The surfaces are cleaned with metal brushes, sandpaper, the material for removing grease and oil stains depends on the brand of glue used: when gluing parts with 88N glue, gasoline is used, acetone is used for EDP and BF-2 adhesives.

The process of gluing parts consists of the following operations:

- prepare the surfaces of the parts and choose the brand of glue (see above);

- apply the first layer of glue on the surface at the joints (this operation can be performed with a brush or watering), dry, apply a second layer of glue, connect the parts and press them together with clamps (here it is important to monitor the exact coincidence of the parts and their tight fit);

- hold the glued knot and clean the seams from glue drips.

Drying mode for the first layer of glue: EAF is applied in one layer and does not require drying; BF-2 requires drying for 1 hour at 20 ° C (“tack-free”); 88H - 10-15 minutes in air. After applying the second layer, let it stand for 3-4 minutes and only then connect the parts.

Holding mode of glued joints: when using EDP glue - 2-3 days at a temperature of 20 ° C or 1 day at a temperature of 40 ° C; BF-2 glue - 3-4 days at a temperature of 16-20 ° C or 1 hour at a temperature of 140-160 ° C; glue 88N - 24–48 hours at a temperature of 16–20 ° C under load.

When assembling machines and mechanisms, sometimes combined glued joints are used - glue-welded: a layer of VK-9 glue is applied to the mating surface of one of the parts, and the second part is welded by spot welding along this layer.

From the book Works on wood and glass the author

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From the book Works on metal the author Korshever Natalia Gavrilovna

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From the book The Art of Hand Weaving the author Tsvetkova Natalia Nikolaevna

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From the book Design Basics. Artistic metal processing [ Tutorial] the author Ermakov Mikhail Prokopyevich

Types of lumber Depending on the purpose of the structural element for which this or that lumber is used, it is necessary to determine its dimensions: - for rafters, beams of basement and interfloor floors, as well as treads of steps of stairs and external

From the book Welding the author Bannikov Evgeny Anatolievich

Types of connections All connections, whether carpentry or joinery, are called landings, because they are based on the principle of fitting a part with a tenon onto a part with a groove. Depending on how tightly the parts in the mount are in contact, all landings are divided into

From the author's book

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From the author's book

Types of joinery and carpentry connections and fasteners All connections, whether carpentry or joinery, are called landings, because they are based on the principle of fitting a part with a tenon onto a part with a groove. Depending on how tightly the parts in the mount are in contact,

From the author's book

5.4 Types of plugs Plugs used in weaving are very diverse. Their diversity is determined by the ratio of three values: Ro of the weave, Rnp. and the number of hedges K. Consider an example when Ro = K = Rnp. In this case, the warp threads in a row make their way into each heald and

From the author's book

1.5. Types of art In the process of the historical development of art, various types of art have developed. The epochs of the highest flowering of art testify to the fact that the completeness of displaying the world is achieved by the simultaneous flowering of all arts. As known. Arts can

State autonomous professional educational institution

"Krasnokamensk Mining and Industrial College"

Agreed at the meeting of the PCC

Minutes No. _____ "____" _________________ 2018

Chairman of the PCC

Kiseleva T.M.

I approve:

Director of GAPOU "KGPT"

S.N. Epifantseva

"_____" _________________ 2018

MDK.01.01. Basics of fitting and assembly and electrical work

by profession average vocational education

13.01.10 Electrician for repair and maintenance

electrical equipment (by industry).

Compiled by: Alexey Morozov

teacher of GAPOU "KGPT"

Krasnokamensk 2018

Content

1. Introduction

2. Explanatory note

3. List of practical works

4. Instructions for practical work

Introduction

The academic discipline "Fundamentals of fitter-assembly and electrical work" is studied by students in the second year. Methodical recommendations for the implementation of practical work ensure the implementation of the work program for the technology of electrical work.

The implementation of the program will ensure the competence of future specialists in the field of life safety as an integral part of their professionalism in the period of entering an independent life.

Explanatory note

The leading didactic goal of practical training isformation of practical skillsrequired insubsequent educational activities and life.

In accordance with the leading didactic purpose, the contentpractical training is the solution of various kinds of problems, includingprofessional (analysis of problem situations, solutionsituational tasks,work with measuring devices, personal protective equipment, training simulator for resuscitation actions, work with regulatory documents, instructivematerials, reference books).

PracticalIn the classroom, students master the initial skills and abilities that they will use in professional activities and life situations.

Along with the formation of skills and abilities in the process of practical training, theoretical knowledge is generalized, systematized, deepened and concretized, the ability and willingness to use theoretical knowledge in practice is developed, and intellectual skills are developed.

As a result of studying the academic discipline in the field of life, the student mustknow:

The main types, operations, purpose, tools, equipment and materials used in electrical work;

Purpose, physical and chemical foundations, methods of soldering with soft and hard solders;

Types of connection of wires of various brands by soldering;

Appointment, methods, materials used for tinning;

Physiological and hygienic basics labor process;

Labor safety requirements in organizations;

Norms and rules of electrical safety;

Measures and means of protection against electric shock.

be able to:

Solder with various solders;

Tinkering;

Apply the necessary materials, tools, equipment;

Apply the rules and regulations of electrical safety.

List of practical works

p / p

Practical work topic

clock

Practical lesson number 1

Practical lesson number 2

Practical lesson number 3

Practical lesson number 4

Practical lesson number 5

Practical lesson number 6Connection of wire cores by means of crimping.

Practical lesson # 7 Fastening and insulation of electrical devices.

Practical lesson number 8Wire stripping.

Total:

Practical lesson number 1 Performing operations of plane marking, cutting, cutting, filing and drilling of metal.

"Markup"

Target: Use the required tool for plane marking. Learn to draw mutually parallel and perpendicular lines

Time: 2 hours.

Equipment and materials .

1. Metal ruler 50 cm, sheet of metal 20x10 cm, 1 mm thick, scribe, compasses.

2. Educational literature.

Exercise.

1.Fix the workpiece to be marked on the workbench.

2. Make a markup.

Drawing parallel lines.

Study task 1. Application mutually parallelscratches at an arbitrary distance from each other using a square, a ruler and a scribe.

The marking task is performed on plates (at least 200X100 mm in size) from

sheet steel in the following order.

1. Place the plate on the marking plate so that the machined edge

taken for the base, was addressed to the worker; while the workpiece is shifted to the edge

marking plate, which ensures a snug fit of the square.

2.An elbow with a wide base is applied to the base edge and carried out

first at risk, the scribe should be tilted towards it

move and at the same time away from the edge of the ruler.

Drawing techniques.

During the drawing of scratches, the pointed end of the scribe is continuously pressed against

the side of the ruler, and the ruler is pressed tightly against the workpiece. The risk is carried out with slight pressure only once - the repeated risk is unacceptable. The risks must be clear, subtle and continuous.

For drawing marks, two types of scribes are used: round or with a plug-in needle made of hard alloy.

3. The square is moved along the edge of the plate at arbitrary distances and

make a number of marks.

Drawing lines (lines)

a - parallel, at an arbitrary distance using a square; b - parallel, spaced at a certain distance, using a measuring ruler; in parallel, spaced at a certain distance, using a compass and a ruler.

Then, along the ruler, connecting the applied marks, draw a line. Straight lines are also drawn through other pairs of marks, which will be parallel.

To draw lines parallel to a given line at a certain distance using a compass and a ruler from arbitrary points a and b on line AB draw arcs with a radius R. Line CD, tangent to these arcs, will be parallel to a given line AB and spaced from it at a distance R.

Exercise 2. Drawing mutually perpendicular marks

1. Draw a line AB of arbitrary length on the surface to be marked (Fig. D).

2. In the middle (approximately) marks AB mark point 1, on both sides of which with the aid of a compass set to the same size, make notches 2 and 3 at the risk AB and mark them.

4. Install the fixed leg of the compass 3. Set the compass to a size greater than half the size between points 1-2 and 1-3 and set the fixed leg of the compass to point 2 and draw an arc "ab" crossing the risk.

at point 3 and draw an arc "bg".

5. Draw through the points of intersection of the arcs and point 1 to the risk "PC", which will be perpendicular to the line AB.

Control questions:

1. What tools are used for plane marking?

2. What methods are used to secure the workpiece to the workbench?

3.Explain the sequence of the planar markingand drawing mutually parallel and perpendicular marks.

"Cabin"

Target: Learn to produce p material removal according to the level of the vise jaws, according to the marking risks

Equipment and materials .

1. Metal of various profiles, locksmith workbench, vice, blanks, chisels. hammers

3. Educational literature.

Exercise.

1.Cut metal at the level of the vise jaws, according to the marking risks.

Tool selection. Pick up and check the hammer: the density and strength of its attachment on the handle; the correct wedging of the handle in the hole with steel wedges; ovality of the handle section with uniform thickening towards the end; lack of knots, cracks and chips on the handle; smoothness and slight convexity of the surface of the hammer head; the absence of cracks and chips at the hammer and striker; the weight of the hammer (40 g per 1 mm of the chisel width) and the length of its handle (500-600 mm). Pick up a chisel and check: the absence of cracks and chips; roundness and cleanliness of the sides and middle part; smoothness and convexity of the striking part; taper angle depending on the hardness of the metal being processed (35, 45, 60, 70 °).

1. A wrist blow with a hammer is produced by swinging only due to the bending of the hand (Fig. C); used for light work, removing thin layers of metal.

Techniques for grabbing a tool and striking when cutting metal.

2. The elbow strike is used in conventional felling, when it is necessary to remove a layer of metal of medium thickness. With an elbow strike, the arm bends at the elbow, so it is stronger than the wrist (Figure b).

3. Shoulder impact is used when cutting thick layers of metal and processing large planes. The arm moves in the shoulder, thus a large swing and a blow of maximum force is obtained - a blow from the shoulder (Fig. C). It must be accurate so that the center of the hammer head hits the center of the chisel head.

4. The location of the fingers on the handle when hitting with a hammer: grasp the handle with four fingers and press it to the palm; put the thumb on the index finger and squeeze all fingers tightly, they remain in this position both during the swing and during the impact; at the beginning of the swing when moving the hand up, grasp the handle of the hammer with all fingers. In the future, as the hand is raised up, the little finger, ring and middle fingers, gradually unclench and support the hammer tilted back (Fig. G); then squeeze the unclenched fingers and accelerate the downward movement of the hand - the result is a strong and well-aimed hammer blow. The blows should be accurate (hitting right on top of the rounded part of the chisel) and uniform - at a speed of about 60 blows per minute for light felling and 40 hits for heavy felling. Exercises. Chopping, cutting metal and cutting grooves. Chopping off a plane and cutting grooves: 1. Cutting along the marking lines at the level of the vise jaws (workpiece 50X30X4 mm): apply a marking line on the surface of the workpiece; clamp and align the workpiece in a vise so that the marking line is parallel to the jaws of the vise and higher by the size of the part of the workpiece that goes into the shavings; check the hammer and chisel (hammer handle attachment, absence of broken corners, broken strikers, burrs on the hammer and chisel; take the correct working position; set the chisel correctly;

chop with the middle of the chisel, hitting it correctly and removing shavings 2-3 mm thick; f) check the cut line with a scale ruler - it should be straight (tolerance ± 0.5 mm). 2. Cutting along the marking risks above the level of the vise jaws (workpiece 150X30X4 mm): a) apply parallel marking marks on the surface of the workpiece (the distance between them is 1 mm); b) install the marked workpiece, align and clamp between the jaws of the vice in the middle part so that the marking risk, along which you need to cut, is parallel to the jaws of the vice and at a level higher than them by 10-15 mm; set the chisel correctly; to remove a chamfer on the side of the workpiece opposite to the one from which cutting begins; make a chamfer according to the size of the metal layer to be removed; cut the surface with the middle of the chisel along the marking risks; the thickness of the layer to be removed should be the same along the entire length (no more than 0.5 - 1.0 mm, and for final felling - 0.2 - 0.5 mm); risk is not cut down; check the cutting line with a scale, it must be straight (tolerance ± 0.5 mm).

Control questions:

1. List the rules of safe work when cutting metal.

2. Name the tools for cutting metal.

3. What is the difference between a chisel and a cross cutter?

4. In what cases is a wrist blow used? Shoulder kick?

5. Why, when cutting in a vice, should the marking line be 1.5 ... 2 mm below the level of the jaws?

"Cutting metals"

Target: Learn to use locksmith tools and cut metal parts

Equipment and materials .

1. Metal for cutting, locksmith's workbench, hacksaw for metal and various blades for it, scissors for metal, pipe cutter, locksmith vice.

3. Educational literature.

Exercise.

1.Cut parts made of various metals.

2. Answer security questions.

1. Cutting metals

When metalworking and procurement works, the metal is cut in those cases when it is necessary to separate a part of a certain size or a given shape from a billet of profiled, shaped steel or pipes. This operation differs from cutting in that it is performed not by shock, but by pressing forces, and the adjacent ends of the main and separated parts of the metal have straight planes without bevels. Strip round, angle or other steel is cut with hand saws in a vice, and pipes - in a clamp.

Before cutting pipes, they are marked on a workbench into blanks of the required length. For accurate marking, a metal ruler up to 3 m long is attached to the edge of the workbench with a stop at one end. The locksmith moves the pipe with one end until it stops and marks the length of the workpiece along the ruler.

Slitting (cutting) - This is an operation associated with the separation of materials into parts using a hacksaw blade, scissors, pipe cutters.

2. Tools and devices used for cutting

Hand locksaw hacksaws are intended mainly for cutting bar and profile steel manually, as well as for cutting thick sheets and strips, cutting grooves in screw heads, cutting blanks around the office and other works. The most common hacksaw blades are 13 and 16mm wide. With a thickness of 0.5 to 0.8mm and a length of 250-300mm. There are two types of hacksaw machines: solid and sliding, allowing you to install a hacksaw blade of different lengths in the machine.

Hand scissors are designed for cutting material in a straight line or in an arc of a large radius.

The hand scissors are available as right and left. Manual scissors can cut sheet steel up to 0.7mm thick, roofing iron up to 1.0mm thick, copper and brass sheets up to 1.5mm thick.

Power scissors designed for cutting sheet steel up to 2.5 mm thick.

Tabletop manual lever scissors used for cutting sheet steel up to 4mm thick, aluminum and brass up to 6mm.

Pipe cutters used for cutting pipes of various diameters instead of a hacksaw, as well as for better cutting pipes. The pipe cutter is a special device in which steel disk cutters-rollers serve as the cutting tool. The most common roller, clamp and chain cutters (for cutting large diameter pipes).

Clamps used for clamping steel pipes and pipe blanks with a diameter of 15 to 50 mm when cutting pipes by hand.

3. Basic rules for cutting metal with a hacksaw (strip, sheet, bar material; profile rolled products; pipes)

1. Before starting work, it is necessary to check the correct installation and tension of the blade.

2. The marking of the cutting line must be made along the entire perimeter of the bar (strip, parts) with an allowance for subsequent processing of 1 ... 2 mm.

3. The workpiece should be firmly clamped in a vice.

4. Strip and corner material should be cut wide.

5. In the event that the length of the cut on the part exceeds the size from the blade to the frame of the hacksaw, cutting must be done with a blade fixed perpendicular to the plane of the hacksaw (hacksaw with a turned blade).

6. The sheet material should be cut directly with a hacksaw if its thickness is greater than the distance between the three teeth of the hacksaw blade. The thinner material for cutting must be clamped in a vice between the wooden blocks and cut with them.

7. The gas or water pipe must be cut and secured in the pipe clamp. When cutting thin-walled pipes, fasten in a vice, using profile wooden spacers for this.

8. When cutting, the following requirements must be observed:

at the beginning of cutting, tilt the hacksaw away from you HB 10..15º;

when cutting, hold the hacksaw blade in a horizontal position;

use at least three-quarters of the length of the hacksaw blade in work;

make working movements smoothly, without jerks, approximately 40..50 double strokes per minute;

at the end of the cut, loosen the pressure on the hacksaw and support the cut part with your hand.

9. When checking the size of the cut off part according to the drawing, the deviation of the cut from the marking notch should not exceed 1mm in the larger direction.

4. Basic rules for cutting sheet metal up to 0.7mm thick with hand scissors

1. When marking the cut out part, it is necessary to provide for an allowance of up to 0.5 mm for subsequent processing.

2. Cutting should be done with sharpened scissors in gloves.

3. Place the sheet to be cut strictly perpendicular to the blades of the scissors.

4. At the end of the cut, the scissors should not be brought together completely to avoid tearing the metal.

5. It is necessary to monitor the condition of the scissors screw axis. If the scissors begin to "crush" the metal, you need to slightly tighten the screw.

6. When cutting material with a thickness of more than 0.5 mm (or when pressing the handles of the scissors with difficulty), one of the handles must be firmly fixed in a vice.

7. When cutting a piece of curved shape, for example, a circle, the following sequence of actions must be observed:

mark the contour of the part and cut out the workpiece with a straight cut with an allowance of 5..6 mm;

cut out the part according to the marking, turning the workpiece clockwise.

8. Cutting should be done exactly along the marking line (deviations are allowed no more than 0.5 mm).

The maximum value of the "undercut" in the corners should not be more than 0.5 mm.

5. Basic rules for cutting sheet and strip material with lever shears

1. Cutting must be done with gloves to avoid cutting the hands.

2. Cutting sheet material of considerable size (more than 0.5 × 0.5 m) should be done by two people (one should support the sheet and advance it in the direction "away from himself" along the lower knife, the other should press the scissors lever.

3. In the process of work, the cut material (sheet, strip) must be placed strictly perpendicular to the plane of the movable knife.

4. At the end of each cut, the knives should not be brought to full compression in order to avoid "tearing" of the cut material.

5. After finishing work, fix the scissor arm with the fixing pin in the lower position.

6. Basic rules for cutting pipes with a pipe cutter

1. The cutting line should be marked with chalk around the entire perimeter of the pipe.

2. The pipe must be firmly fixed in a pipe clamp or vise. Fastening the pipe in a vice must be done using profile wooden gaskets. The place of the cut should be located no further than 80..100 mm from the clamping jaws or vice.

3. During the cutting process, the following requirements must be observed:

lubricate the cutting site;

monitor the perpendicularity of the pipe cutter handle of the pipe axis;

make sure that the cutting discs are cut accurately, without skewing, along the cutting line;

do not apply great effort when turning the screw of the pipe cutter handle to feed the cutting discs;

at the end of the cut, support the pipe cutter with both hands; make sure that the cut piece of pipe does not fall to your feet.

7. Typical defects when cutting metal, the reasons for their appearance and how to prevent

Cutting with a hand saw

Defect

Cause

Prevention method

Misalignment of the cut.

The canvas is loosely stretched.

Cutting was carried out across the strip or flange of the square.

Stretch the blade in such a way that it is pressed tightly with your finger from the side.

Crumbling

blade teeth.

Incorrect blade selection. Defect canvas - canvas overheated.

The blade should be selected in such a way that the pitch of the teeth is no more than half the thickness of the workpiece, that is, so that two or three teeth are involved in the work. Cut viscous metals (aluminum and its alloys) with finer-toothed blades, fix the thin material between wooden blocks and cut with them.

Breakage of the canvas.

Pressing firmly on the hacksaw. Weak blade tension. The canvas is overstretched. Uneven movement of the hacksaw when cutting.

Loosen the vertical (lateral) push on

a hacksaw, especially when working with a new, as well as a tightly stretched blade. Loosen the pressure on the hacksaw at the end of the cut. Make movements with a hacksaw smoothly, without jerking. Do not try to correct the skewed cut by skewing the hacksaw. If the blade is dull, it must be replaced.

Control questions:

1. What caused the need to use gloves when cutting metal with scissors?

2. Why do I need to lubricate the teeth of the hacksaw blade when working?

3. At what distance from the edge of the jaws of the vise or clamp should the marking line be when cutting the pipe with a hacksaw or pipe cutter?

4. What defects are encountered when cutting metal?

5. What safety rules must be followed when cutting metal

5. For what purpose are the teeth of the hacksaw blade set?

6. On the hacksaw blade there is a marking: 250; thirteen; 1.6; P9. Decipher it.

Bending sheet metal

"Hole drilling"

Target: Learn to use locksmith tools and drill metal blanks

Equipment and materials .

1. Blanks for drilling,drilling machine, drills, countersinks

3. Educational literature.

Exercise.

1. Make drilling of metal blanks on a drilling machine.

2. Answer security questions.

1. Types and techniques of drilling

Drilling - This is an operation for the formation of through and blind holes in a solid material, performed using a cutting tool - a drill.

Distinguish between manual drilling - manual pneumatic and electric drilling devices (drills) and drilling on drilling machines. Hand-held drilling devices are used to produce holes up to 12mm in diameter in materials of small and medium hardness (plastics, non-ferrous metals, etc.). For drilling and processing large-diameter holes, increasing labor productivity and quality of processing, table-top drilling and stationary machines are used - vertical drilling.

Holes are drilled:

According to preliminary markup (made with a marking tool), single holes are drilled according to the marking. Preliminarily, axial marks are applied to the part, then recesses are punched in the center of the hole. The core hole of the circle is made deeper to give preliminary guidance to the drill. Drilling is carried out in two steps - first, test drilling is performed, and then the final one.

By pattern - the use of a template saves time, since the contours of the holes previously marked on the template are transferred to the workpiece.

Large holes drilled in two steps - first with a drill of a smaller diameter, and then with a drill of the required diameter.

Drilling blind holes to a specified depth carried out on a bushing stop on a drill or a measuring ruler. To measure, the drill is brought in until it touches the surface of the part, drilled to the depth of the drill cone and the initial position on the ruler is marked on the arrow (pointer). Then the specified drilling depth is added to this indicator and the figure to which drilling must be carried out is obtained.

Drilling incomplete holes (half holes) in cases where the hole is located at the edge, a plate of the same material is attached to the workpiece, clamped in a vice and a full hole is drilled, then the plate is removed.

Drilling for thread and reamer.

There are general rules for drilling (both on a machine and with a drill):

* in the process of marking work, the center of the future hole must be marked with a center punch, then during work the drill is installed in the core, which contributes to greater accuracy;

* when choosing the diameter of the drill, you should take into account its vibration in the chuck, as a result of which the hole is slightly larger than the drill. This deviation is quite small - from 0.05 to 0.3 mm - and is important in the case when special accuracy is required;

* when drilling metals and alloys as a result of friction, the temperature of the cutting tool (drill, countersink) increases significantly, which leads to its rapid wear. In order to increase the durability of the tools, cooling liquids, in particular water, are used when drilling;

* Blunt cutting tools not only form low-quality holes, but also fail faster themselves, so they should be sharpened in a timely manner: drills - at an angle (at the top) of 116-118º, tapered countersinks - 60, 90, 120º. Sharpening is carried out manually on a sharpening machine: the drill is placed on the circle of the sharpening machine with one of the cutting edges at an angle of 58-60º and smoothly rotated around its axis, then the second cutting edge is sharpened in the same way.

In this case, it is necessary to ensure that both cutting edges are sharpened at the same angle and have the same length;

for drilling blind holes on many drilling machines there are automatic feed mechanisms with limbs, which determine the drill stroke to the desired depth. If your machine is not equipped with such a mechanism or you are drilling with a hand drill, then you can use a drill with a sleeve stop;

* if you need to drill an incomplete hole located at the edge of the part, then put a plate of the same material on the part, fix the whole bag in a vice and drill a hole. The plate is then removed;

* when it is necessary to drill a hole in a complete part (for example, in a pipe), the hole is pre-filled with a wooden plug. If the pipe is of large diameter, and a through hole is required, then you have to drill from both sides.

In this case, in order to facilitate the marking and make it the most accurate, you can use a special device. It consists of two completely identical prisms, between which the pipe is clamped. Each prism has counter punch screws precisely aligned against each other and clamped at their opposite vertices. The prisms are also precisely aligned using the lateral cheeks. When the pipe is clamped between the prisms, small, opposite punch holes are left on it. After drilling according to such a marking, the holes in the pipe will correspond to each other with much greater accuracy;

* you can get stepped holes in two ways: the first way: first, a hole of the smallest diameter is drilled, then (to the required depth) - a hole of a larger diameter and the last hole of the largest diameter is drilled; the second method: exactly the opposite: first, a hole of the largest diameter is drilled to the required depth, then a smaller one, and at the end - the smallest diameter;

* if you need to drill a hole on a curved plane or a plane located at an angle, then first you should make (cut, cut) a platform perpendicular to the axis of the future hole, turn the center, and then drill the hole;

* holes with a diameter over 25mm are drilled in two steps: first, the hole is drilled with a drill of a smaller diameter (10 ... 20mm), and then drilled with a drill of the required diameter;

* when drilling parts with a large thickness (with deep drilling), when the depth of the hole is more than five diameters of the drill, it must be periodically removed from the hole and blown out the chips, otherwise the tool may jam;

* Composite (consisting of several dissimilar layers) materials are difficult to drill, primarily because cracks appear on them during processing. This can be avoided very much in a simple way: before drilling, such material must be filled with water and frozen - cracks in this case will not appear;

* high-strength materials - steel, cast iron - ordinary drills are not taken. For their drilling, drills with tips from the so-called Pobedit are very popular among locksmiths. It was obtained in Russia in 1929 and consists of 90% tungsten carbide and 10% cobalt. For the same purpose, you can also get a diamond drill, the tip of which is made using synthetic diamonds - it significantly increases the speed of metal drilling.

Control questions:

1. What determines the different shapes and angles of the cutting edge of the drill?

2. What determines the wear of the cutting rod tool for machining holes?

3. What determines the cutting speed when machining a hole?

4. What equipment is used for drilling?

5. What safety rules must be followed when drilling with a hand drill?

6. What is the sequence in which the drill is sharpened?

7. How to reduce friction when drilling?

8. What types of drills are used in plumbing?

9. What defects can be encountered and how to eliminate them when machining holes?

10. What safety rules must be followed when drilling with an electric drill?

11. How to determine the suitability of the workpiece?

12. What safety rules must be followed when drilling parts?

Filing a part

Target: Learn to use locksmith tools and filing parts

Equipment and materials .

1. Metal blanks, locksmith workbench, vice, set of files

2. Drawing details

3. Educational and technical literature.

Exercise:

1. Learn the theoretical foundations

2.Carry out filing of the workpiece

3. Answer security questions

Theoretical basis

Table 1. the classes of roughness and the corresponding values ​​of the heights of microroughness of the surface, obtained with different types of locksmith processing, are given.

Table 1

Surface roughness obtained with different types of locksmithing

Correct and reliable fastening of the material in a vice or device during filing ensures precise processing of the material, minimal worker effort and labor safety.

To avoid damage to the surfaces of non-metallic materials and products fixed in a vice, pads should be used. Pads made of soft metals (copper, zinc, lead, aluminum, brass), wood, plastic, felt or rubber are applied to the cheeks of the vice. The product or material is inserted between the pads and then secured.

The height of the vise when filing should be selected in accordance with the height of the worker. In practice, the installation height of the vise is determined by resting the elbows on the cheeks of the vise (the fist with the vertical position of the hand should reach the chin of the worker standing straight). If the vise is installed below this position, then put gaskets, and if the installation height of the vise is large, then the gaskets are removed or a stand or ladder is placed under the locksmith's feet. The person working in the vise should take such a position so that the feet are at an angle of 45 ° to each other, and the left leg should be put forward at a distance of 25-30 cm from the axis of the right foot. The axis of the left foot in relation to the working axis of the file should be at an angle of about 30 °. This position guarantees productive and safe work of the locksmith and reduces his fatigue.

The restoration of the cutting ability of the file after wear is ensured by removing dull teeth and applying a new cut to the file. Restoration is carried out by annealing the file, grinding off the old notch and making a new one (manually or mechanically), followed by hardening. The file can be restored several times, but each time it becomes thinner and more prone to cracking.

Files must be protected from moisture to prevent corrosion; to avoid damaging the notches, do not throw them or place them on other files, tools or metals. The surface of the files is protected from the ingress of oil or grease, as well as from the ingress of dust from the grinding wheels.

A new file should be used first on one side, and after dulling on the other. Personal and velvet files should not be used for filing soft metals (tin, lead, copper, zinc, aluminum, and brass). Sawdust of these metals clogs the grooves of the file notch and makes it impossible to process the surfaces of other metals.

The file should be cleaned with a steel brush during and after work. After finishing work, it is put into a drawer or cabinet.

Pay special attention to the condition of the handle and its correct attachment to the file (the handle is inserted along the axis of the file). When attaching the handle, do not lift the file up. Files without a handle should not be used. Use especially caution when working with small files. Do not grip the end of a long file with your fingers. The filing material must be secured correctly and firmly.

Control questions:

1. Name the methods of cleaning files

2. TB when working with files

3. In what order is the restoration of the cutting ability of the file carried out?

4. What is an example of the roughness of the surface obtained with different types of locksmithing?

Practical lesson number 2 Soldering of aluminum and copper conductors of wires.

Target: Learn to perform operations on soldering aluminum conductors and wires.

Time: 2 hours.

Equipment and materials .

1. Solder, soldering irons, copper and aluminum conductors.

3. Educational literature.

Exercise. Solder the cores.

Information from theory

Soldering - this is the process of obtaining a permanent connection of materials with heating below the temperature of their autonomous melting by wetting, spreading and filling the gap between them with molten solder and adhering them during the crystallization of the seam.

Brazing is widely used in various industries. In mechanical engineering, it is used in the manufacture of turbine blades and disks, pipelines, radiators, fins of air-cooled engines, bicycle frames, industrial vessels, gas equipment, etc.VIn the electrical industry and instrument making, soldering is in some cases the only possible method of joining parts. It is used in the manufacture of electrical and radio equipment for televisions, electrical machine parts, fuses, etc.

The advantages of soldering include: insignificant heating of the parts to be joined, which preserves the structure and mechanical properties of the metal; the purity of the compound, which in most cases does not require further processing; preservation of the size and shape of the part; bond strength.

Modern methods allow brazing carbon, alloyed and stainless steels, non-ferrous metals and their alloys.

Solders. The quality, strength and operational reliability of the soldered joint primarily depend on the correct choice of solder. Not all metals and alloys can act as solders.

Solders must have the following properties:

have a melting point below the melting point of the materials to be soldered;

in the molten state (in the presence of a protective medium, flux or in a vacuum), it is good to wet the brazed material and easily spread over its surface;

ensure sufficiently high adhesion, strength, ductility and tightness of the soldered joint;

have a coefficient of thermal expansion close to the corresponding coefficient of the brazed material.

Depending on the melting point, solders are classified as follows: solid (refractory) - high-strength, having a melting point above 500 ° C; soft (low-melting) - less strength, having a melting point below 500 ° C.

Low-melting solderswidely used in various industries and households; they are a tin-lead alloy. Different quantitative ratios of tin and lead determine the properties of solders.

Tin-lead solders, in comparison with others, have high wetting ability, good corrosion resistance. When soldering with these solders, the properties of the metals being joined practically do not change.

Refractory soldersare refractory metals and alloys. Of these, copper-zinc and silver are widely used. To obtain certain properties and melting points, tin, manganese, aluminum, iron and other metals are added to these alloys.

The addition of small amounts of boron increases the hardness and strength of the solder, but increases the brittleness of the brazed joints.

Fluxes. With an increase in temperature, the rate of oxidation of the surface of the parts to be brazed increases significantly, as a result of which the solder does not stick to the part. To remove the oxide, chemicals calledfluxes.Fluxes improve the conditions for wetting the surface of the brazed metal with molten solder, protecting the surface of the brazed metal and molten solder from oxidation during heating and during the soldering process, dissolve oxide films on the surface of the metal and solder being brazed.

There are fluxes for soft and hard solders, as well as for brazing aluminum alloys, stainless steels and cast iron.

Electric soldering device . 1 - tip; 2, 6 - nuts; 3 - tube; 4 - thermocouple; 5 - ceramic tube; 7 - base; 8 - screw; 9 - bushing; 10 - heat-resistant insulating tubes; 11 - handle; 12 - holder (plate); 13 - a bundle of power, thermocouple and ground wires; 14 - heating element; 15 - wire for grounding.

Preparing the soldering iron for work ... A new soldering iron is first "fired" so that the threads, various inclusions in the best, oil coating, etc. are burned out in it. The tip of the ironing iron should have the shape of a wedge with an angle of 55 ... 60 °, which is better obtained by forging to create a work hardening. Plaque slows down the dissolution of copper in rosin and prevents the appearance of shells on the sting. After that, the sting is filed with a file so that the edges are smooth and a back angle of 10 ... 15 ° is formed on the sting. This shape of the tip facilitates the flow of solder into the solder seam.

A washed-down or dirty soldering iron must be tinned, that is, covered with a thin layer of solder. To do this, after sufficient warming up, the soldering iron tip must be immersed in rosin and brought along a piece of solder with a facet. If the soldering iron is warmed up normally, but did not get tired, all operations should be repeated.

Soldering technology. The soldering process is as follows. Pre-stripped leads of parts, wires, etc., are covered with a thin layer of solder (tinned). Then the parts are soldered and tightly applied to each other. The required amount of solder and rosin is taken on the soldering iron. The soldering iron is applied to the heavier part in such a way as to ensure the best heat transfer. After spreading the molten solder, it is distributed by smooth movement of the soldering iron. It is recommended to have two purchases of rosin: the first one for cleaning the soldering iron, the second one for soldering.

To provide reliable contact connection when soldering, the following requirements must be met:

1. The tip of the soldering iron must be free of shells and well tinned.

2. The soldering iron should be well warmed up. A sign of sufficient heating is rosin boiling (but not burning) and abundant smoke.

3. The amount of flux introduced into the place of soldering should be minimal. The flux must not spread beyond the soldering point.

4. The amount of solder introduced into the soldering point is determined empirically in such a way that the holes are filled and the contours of the parts are visible.

5. The place of soldering should be sufficiently warmed up by the soldering irons until the solder completely spreads out.

6. The parts to be connected must be motionless untilfloorsolidification of the solder.

7. Soldering time for one contact connection - no more than 5 seconds.

To increase the mechanical strength, the tinned conductor is mechanically fixed at the contact, and the soldering provides electrical conductivity between the parts to be soldered. Soldering "overlap" or "butt" is allowed only in laboratory models. When overheated, the soldering turns out to be dark and rough, and when underheating, it is fragile, and it takes a lot of time to complete it.

Quality control of soldered joints ... The quality of the soldering is checked by external examination, if necessary, using a magnifying glass. A well-performed soldering should be considered one on which the contours of the connected parts (turns, rings, bends) are clearly visible, but all the slots are filled with solder. The soldering has a glossy surface, without cracks, sagging, sharp bulges.

The mechanical strength of the soldering is checked with tweezers with polyvinyl chloride tubes put on its ends. The tensile force along the axis of the wire should be no more than 10 N. It is prohibited to bend the wire near the soldering point. All soldered wire cores and leads of electrical components are subject to inspection. The ambassadors for the control of the soldering and acceptance of the junction are painted with a transparent colored varnish, applied to the junction in the form of a small smear with a soft brush.

Safety . When soldering and tinning, certain safety requirements must be followed.

Workplaces designed to perform work on soldering small parts must be equipped with local exhaust devices that provide an air speed of at least 0.6 m / s directly at the soldering point.

In the rooms where the soldering work was carried out, the floors must be washed (dry cleaning of the floor is not allowed).

Storing clothes in rooms where soldering is performed is prohibited.

In the immediate vicinity of the workplaces intended for the performance of work on soldering small parts with soft solders, the following should be installed: a washbasin; a tank with a 1% solution of acetic acid for preliminary washing of hands; easy-to-clean portable containers for collecting paper or cotton napkins and rags. There should always be soap, brushes and napkins near the washbasin for wiping hands (use of shared towels is not allowed).

The preparation of metals and the soldering process are associated with the release of dust, as well as harmful vapors of non-ferrous metals and salts, which cause irritation of the mucous membrane of the eyes, skin damage and poisoning. Therefore, when soldering and tinning, the following safety rules must be observed:

the workstation of the solder should be equipped with local ventilation;

work in gas-polluted rooms is not allowed;

at the end of work and before eating, hands should be thoroughly washed with soap;

chemicals must be filled with care, in small portions, avoiding splashes (acid in the eyes can cause blindness; acid fumes are also very harmful);

manual operations (washing, wiping products, bottling, etc.) are not allowed, in which direct contact of the skin of a person working with dichloroethane (flammable poisonous liquid) or mixtures containing it is possible;

when heating the soldering iron, the general rules for safe handling of the heating source should be observed;

it is necessary to conduct a visual inspection of tools and equipment, make sure it is in good working order;

for an electric soldering iron, the handle must be dry and non-conductive;

the student's seating position should be straight, the elbows should touch the plane of the table, the distance from the soldering point to the eyes should be 350 ... 400 mm, the soldering iron should be held like a pencil.

Control questions:

1. In what ways can you get a contact connection?

2. Give the characteristics of the brands of soldering fluxes known to you.

3. Solders for soldering. General requirements.

4. Give the characteristics of the brands of solders known to you and their fields of application.

5. Describe the methods of removing fluxes after soldering known to you.

Practical lesson number 3 Performing operations for cutting external and internal threads.

Target: Learn to use locksmith tools and cut external and internal threads

Time: 2 hours.

Equipment and materials .

1. Blanks for cutting internal and external threads, taps, dies, wrenches, oilers

3. Educational literature.

Exercise.

2.Cut an internal metric M10 thread and assess the quality of the thread

3. Answer security questions.

Information from theory

Tapping internal threads

The internal thread is cut by hand with taps. The tap consists of a working part and a shank. The shank ends with a square on which the driver slips during threading. The working part consists of an intake and a calibrating part. The intake (tapered) part of the tap removes the bulk of the chips and forms a thread in the hole. The calibrating part calibrates the cut threads. To form cutting edges, three or four longitudinal grooves are made on the taps; the number of grooves depends on the size of the tap. Large taps have four flutes, small taps have three. Chips come off along these grooves during operation.

Tap (appearance and main elements).
The dimensions of the tap and its number in the kit are usually applied to the cylindrical part of the shank. For metric threads, the outer diameter and pitch are indicated, for example: M 8x1.25: this means that the thread is metric with an outer diameter of 3 mm with a pitch of 1.25 mm.

Currently, two-piece taps are produced for the main fastening metric thread up to 26 mm, i.e. a set of such taps consists of two pieces. The first, preliminary tap, is called rough, the second - finishing and has two risks on the shank. The first tap, in addition, has a longer intake part and a blunt thread than the second. The second tap on the gauge section has a full thread profile. The thread is cut first with a rough and then with a finishing tap.

A thread hole must be drilled in the workpiece before tapping. The diameter of the drill for drilling such a hole is selected depending on the size of the thread according to special tables. The drill diameter should be less than the outer diameter of the thread and slightly larger than its inner diameter. So, for example, for threads M8, M10, M12 and MI6 when machining steel, drills are selected for the thread, respectively 6.7; 8.5; 10.2 and 14 mm. The size of the drill will also depend on the material being cut. For cast iron and bronze, the size will be smaller than for steel and brass. If the hole is made smaller than required, the tap may break when tapping. Larger hole sizes may result in incomplete threads.

The threading process is performed by the following working methods:

1. The tap soaked in oil is inserted with a shank into one of the square holes of the tap, and then set in a vertical position;

2. Keeping the vertical position of the tap, and pressing the knob with your hands, turn the tap clockwise until the tap hits the metal (I, 5-2 turns);

3. Without applying vertical force, changing the position of the hands, turn the tap half a turn clockwise, then a quarter turn back counterclockwise, etc. until complete threading with the first tap;

4. The thread is cut in the same way with a finishing tap. A finishing tap is introduced into the pre-cut hole without much effort, after which a knob is put on it and the thread is cut.

Thread control is carried out with a thread gauge or a mating part (bolt).

Methods for cutting internal threads.
In plumbing, dies of various designs are used. The most widespread are round scarves.

The round die is a kind of "nut" made of tool steel. It drilled several holes for the chips, which form the cutting edges on the cone. They serve the same function as the tap grooves. On both sides of the die, there are intake cones, one or two threads long.

Four conical grooves are drilled from the outer cylindrical surface of the die and one longitudinal notch is made at an angle of 60 °. Conical grooves are used to secure the die with screws in the ram-holder

When cutting external threads with dies, the diameter of the rod "under the thread" must be less than the outer diameter of the thread by 0.2 of the profile height. For example, for threads M8, M10, MI2 and Ml6, the rods must have respectively a size of 7.85; 9.80; 11.82 and 15.76 mm. The end of the rod should be sawn down perpendicular to the axis and the receiving chamfer should be sawed off to facilitate the plunging of the die.

Tool for cutting external threads.
For: threading the rod in a vertical position is clamped in a vice to the required height, Then a die fixed in the ram holder is applied to the end of the rod. Keeping the position of the ram holder perpendicular to the axis of the rod, the ram is forcefully turned clockwise until it is cut into 1-2 threads. Then a lubricant is applied to the rod. Keeping the same direction of movement as the tap (half a turn clockwise and a quarter turn counterclockwise), a thread is cut on the rod. No vertical force is applied to the die.

Fig. 37. Techniques for cutting external threads.
Applied in can be divided into 2 main groups: detachable and one-piece. A detachable connection of parts is also a connection in which its constituent parts can be disassembled. One-piece is a connection of parts, in which disassembly of the assembly is possible only if the fastener or the parts themselves are destroyed. Detachable connections include threaded, keyed, spline, pin and wedge connections; to one-piece - riveted, welded, press and adhesive connections.
Threaded connections

TO threaded includes connections in which mating parts are connected using threads or threaded fasteners (bolts, nuts, screws, studs, etc.).

Control questions:

1. In what order are female threads manually cut?

2. When are two and three tap sets used?

3. What causes thread breakage when threading?

4. What types of defects are possible when working with blunt tools?

5. What safety precautions must be observed for manual threading

Practical lesson number 4 Making connections of wire cores using bolt clamps.

Target: learn to connect the cores of the wires using bolt clamps.

Time: 2 hours.

Equipment and materials .

1. conductors of wires, terminals, bolted connections, couplings.

3. Educational literature.

Task: Perform a wire connection using a bolt clamp.

1. Connection of wires using bolt terminal blocks.

Bolt terminal blocks are insulated terminals to which wires are connected using bolts. They are widely used when connecting different luminaires.

Everything is simple here. We strip the cable cores half the width of the terminal itself, insert them on both sides and tighten the screws.

Here it is necessary to choose the correct size of the terminal block for the corresponding wire cross-section. The option that was available in the nearest store may not work, since a thin wire in a too large terminal may fall to the side between the bolt and the terminal wall. This will result in poor contact and overheating of the connection.

The disadvantages of such a connection are:

The insulating body may crack, which I have often encountered.

You can rip off the thread on the screw, as you want to tighten it more securely. As a rule, in such situations, many tighten the screw to the tightest position and leave it there, because there is no other bolt or terminal block to replace. It also leads to poor contact.

The screw can severely crush the aluminum wire, which can quickly break later.

It is not convenient to put it in a junction box.

The advantages include the fact that they can be used to connect the load to very short wires sticking out of the wall.

2. Bolted connection

Another type of connection of electrical wires with a solid experience is bolted. It is called so because a bolt, nut and several washers are used to connect the wires. The contact due to the use of washers is quite good, but the whole structure takes up a lot of space and is inconvenient to lay. It is mainly used if it is necessary to connect conductors made of different metals - aluminum and copper.

Connection assembly order:

We strip the wires from insulation.

From the stripped part, we form a loop, the diameter of which is equal to the diameter of the bolt.

We put on the bolt in the following sequence

• washer (it rests against the head of the bolt);

  one of the conductors;

  another washer;

  second conductor;

  the third washer;

We tighten everything with a nut.

Control questions:

1. In what order are the wires connected?

2. Ways to strip the wires?

5. What safety rules must be followed when connecting wires.

Practical lesson number 5 Tinning and soldering of conductors of wires and cables.

Objective: To study the design and technology of obtaining permanent joints. Get practical skills in soldering, tinning.

Time: 2 hours.

Equipment and materials .

1. Power tools, fluxes.

2. Samples for work

Task: Perform soldering and tinning of wires.

Theoretical information

Soldering. It is a process of joining parts using a special filler bonding material - solder and an auxiliary protective material - flux.

Low-melting and high-melting solders are used.

Low-melting solders (soft) are made on the basis of an alloy of tin (O) with lead (C) and are designated by the letters POS with numbers showing the percentage of tin. Their melting point is less than 500 ° C: They are used for brazing steel, copper, zinc, lead, tin, gray iron, aluminum, ceramics, glass, etc. Joints made with low-melting solders are tight, but not particularly strong. To obtain special properties, antimony, bismuth, cadmium and other metals are added to tin-lead solders. For plumbing work, POS-40 solder is most often used.

Refractory solders (solid) have a melting point of more than 500 ° C and are designed to obtain strong joints that are resistant to temperature and corrosion conditions. They solder steel, cast iron, copper, nickel and their alloys. They are divided into copper-zinc (PMTs brands) and silver solders.

Fluxes are designed to ensure the wetting of the surface of metals with solder, to protect the surface of metals and solder from oxidation when heated, and to dissolve oxide films.

There are fluxes for soft low-melting solders (zinc chloride, ammonia, rosin, pastes, etc.), for hard refractory solders (borax, boric acid, etc.), as well as for brazing aluminum alloys (mixtures of sodium fluoride, lithium chloride, chloride potassium, zinc chloride, etc.), stainless steel (a mixture of borax and boric acid), cast iron (a mixture of borax and zinc chloride).

The metal soldering process includes the preparation of the product, the soldering iron for soldering and the soldering of the product itself.

Preparation of the product consists in cleaning its surface from dirt, grease, oxides, corrosion, scale.

Such cleaning can be carried out: - mechanically using sandpaper, files, metal brushes, grinding wheels, steel or cast iron beads; - by chemical degreasing with Viennese lime diluted with water, applied with a brush to the products; - by chemical etching when the product is immersed in solutions of sulfuric, hydrochloric and other acids; - using ultrasound, acting in a bath with solvents.

Preparation of the soldering iron (Fig. 3.6) includes refueling the working part at an angle of 30 ... 40 ° with dulling the top, cleaning it from scale and applying (tinning) to the end part of the solder.

When soldering, the underheating and overheating of the soldering iron must not be allowed. In the first case, the solder cools down quickly, forming a fragile connection, in the second (above 500 ° C), scale is formed and the tinning of the working part on the soldering iron is difficult.

On tightly fitted parts, liquid flux is applied with a brush, and solid (rosin) - by rubbing while heating the soldering point with a soldering iron. With a deserved soldering iron, 2 ... 3 drops of molten solder are taken from the solder bar and transferred to the place of soldering, covered with flux. After the metal warms up, the solder spreads when the soldering iron is moved, filling the seam gaps. The cooled solder has a shiny surface. The protrusions on the solder are removed with a file.

At mass production Soldering of parts can be carried out by immersion in a bath of molten solder.

Tinning. The essence of this locksmith operation consists in applying a thin layer of tin or tin alloys (with lead, zinc, bismuth, etc.) to the part in order to protect surfaces from corrosion and oxidation, giving them the necessary properties, for example, for decorative surface treatment during manufacturing art products or surface preparation of bearings before babbitting, before brazing. This layer is called half-moon.

Fig. 1. Soldering iron preparation:
a - filling the working part; 6 - cleaning the working part with zinc chloride; c - applying solder; 1 - zinc chloride; 2 - solder

Before tinning, the surfaces of the parts are treated to a pure metallic luster either by a non-chemical method (with files, a steel or hair brush with wet sand, grinding) or by a chemical method for the purpose of degreasing (in a caustic soda solution during boiling, Viennese lime, gasoline, etc.) and etching ( in a heated hydrochloric acid solution). The tinning process is carried out in two ways (Fig. 2): immersion in half a dozen (a), poured into a clean dish, with pieces of charcoal (to protect against oxidation) and rubbing, by preliminary applying tow on the surface of the part with zinc chloride and subsequent application from a bar with heated solder (c) and rubbing it with tow (b). After tinning, the parts are washed with water and dried.

Rice. 2. Tinning of a part: a - by immersion; c - applying solder; b - rubbing the solder with tow; 1 - pieces of charcoal at noon; 2 - solder

Safety engineering

A worker performing metallization, tinning or soldering operations comes into contact with molten metal, acids, alkalis and vapors of various caustic and harmful substances for the body.

The rooms in which the above operations are performed must have good ventilation.

Workers must have protective clothing, goggles and gloves. The blowtorch must be technically sound. When pumping fuel, you must not create high pressure, and you must also not add fuel to a heated lamp. Acids and alkalis should be kept in glass bottles, and they must be diluted by adding acids to the water, and not vice versa. The workplace should be free of rags, spilled oil and grease.

Control questions:

1. What is soldering?

2. Describe the tinning process and the materials used in this process

3. List the solders and fluxes used in soldering

5. What safety rules need to be observed during metallization, tinning and soldering.

Practical lesson number 6 Making the connection of the cores of the wires using

crimping.

Objective: Connect the cores by crimping.

Time: 2 hours.

Equipment and materials .

1.Wire

2. Crimping

3. Educational and technical literature

Exercise: Terminate a stranded copper conductor using stamped lugs.

Theoretical information

Termination - this is the design of the end of a conductive core for inclusion in an electrical circuit.

Crimping Is a method of connecting conductive conductors of wires and cables using sleeves or terminating conductors of wires and cables using lugs.When crimpingthe core of the wire or cable is inserted into the tubular part of the tip or speciala special sleeve and squeezed with a matrix and a punch. At the same time, the contactthe pressure created between the sleeve and the conductor ensures a reliableelectrical connection

Termination of solid copper conductors 1 ... 2.5 mm or stranded up to 1.5 mmperformed with a ring or a pin, depending on the design of the clamps.

The sequence of technological operations during installation:

removal of insulation over a length of 10 ... 15 mm for a pin and over a length of 30 ... 35 mm for a ring;

stripping the vein to a metallic sheen;

compaction of the twisting of wires in the vein;

folding the core into a ring with round-nose pliers in accordance with the screw diameter;

fastening around the core;

covering the ring or pin with a flux;

immersion in molten solder for 1 ... 2 seconds or tinning with a soldering iron;

insulation with adhesive tape of the bare part of the core with an overlap of 5 ... 10 mm of the main insulation.

Termination of stranded copper and aluminum conductors with a cross-sectional area of ​​1.5 ... 240 mm 2 performed with cable lugs by crimping (table 3.2).

The tip is selected according to the cross-sectional area of ​​the core, the inner cylindrical part of it is cleaned with a steel brush to a metallic sheen and covered with rosin. Insulation is removed from the end of the wire to the length of the cylindrical part of the tip plus 10 mm, degreased with a cloth soaked in gasoline, cleaned to a metallic sheen, covered with rosin and tinned. A tip is put on the core, 1 ... 3 layers of asbestos cord are wound under its end to prevent the solder from leaking out. Core and lug with wire cross-sectional area up to 10 mm 2 heated with a soldering iron, and with a larger one - with a blowtorch or propane-butane torch to the melting temperature of the solder. The solder is melted into the sleeve. At the same time, make sure that it penetrates between the wires of the core. With a cloth moistened with soldering ointment, smooth out the smudges of solder along the surface of the tip. After the tip has cooled, the asbestos winding is removed and the termination is isolated

Table 1. Examples of the execution of the termination of cores of wires and cables with cable lugs by crimping

Explanatory drawings