Name the main locksmith operations. Preparatory locksmith operations. Basic plumbing operations and their purpose

Marking.

Mechanic's workplace.

Topic 25. Basics of plumbing.

Questions:

1. Locksmith work – this is manual processing of materials, fitting of parts, assembly and repair of various mechanisms and machines.

Workplace refers to a part of the production area with all the equipment, tools and materials located on it that are used by a worker or a team of workers to complete a production task.

The workplace must occupy the area necessary for the rational placement of equipment and the free movement of the mechanic during work. The distance from the workbench and shelving to the mechanic should be such that he can use predominantly hand movements and, if possible, avoid turning and bending the body. The workplace should have good individual lighting.

Mechanic's workbench(Fig. 36) – the main equipment of the workplace. It is a stable metal or wooden table, the lid (tabletop) of which is made from boards 50...60 mm thick of hard wood and covered with sheet iron. Single-seat workbenches are the most convenient and common, since on multi-seat workbenches, when several people work simultaneously, the quality of precision work is reduced.

Rice. 36 Single bench:

1 – frame; 2 – table top; 3 – vice; 4 – protective screen; 5 – tablet for drawings; 6 – lamp; 7 – shelf for tools; 8 – tablet for working tools; 9 – boxes; 10 – shelves; 11 – seat

The tools necessary to complete the task are placed on the workbench. The drawings are placed on a tablet, and the measuring instruments are placed on the shelves.

Under the workbench tabletop there are drawers, divided into a number of cells for storing tools and documentation.

To secure the workpieces, a vice is installed on the workbench. Depending on the nature of the work, parallel, chair and hand vices are used. The most widely used are parallel rotary and fixed vices, in which the jaws remain parallel when opened. The rotating part of the vice is connected to the base with a center bolt, around which it can be rotated to any angle and secured in the required position using a handle. To increase the service life of the vice, steel overhead jaws are attached to the working parts of the jaws. Chair vices are rarely used, only for work involving impact loads (for chopping, riveting, etc.). When processing small parts, a hand vice is used.

Selecting the height of the vice according to the height of the worker and rational placement of the tool on the workbench contribute to better development of skills, increased productivity and reduced fatigue.

When choosing the installation height of the vice, place your left arm bent at the elbow onto the jaws of the vice so that the ends of the straightened fingers touch the chin. Tools and devices are placed so that they can be conveniently taken with the appropriate hand: what is taken with the right hand is held on the right, what is taken with the left is held on the left.

A protective screen made of metal mesh or durable plexiglass is installed on the workbench to contain pieces of metal flying off during chopping.

Blanks, finished parts and fixtures are placed on racks installed in the area allocated for them.

2. Marking - the operation of applying lines (scores) to the workpiece, defining (according to the drawing) the contours of the part and the places to be processed. Marking is used for individual and small-scale production.

Markings are carried out on marking plates cast from gray cast iron, aged and precisely machined.

Lines (marks) for planar markings are applied with a scriber, for spatial markings - with a scriber fixed in the clamp of the planer. Scribblers They are made from steel grades U10 and U12, their working ends are hardened and sharpened.

Kerner designed for making indentations (cores) on pre-marked lines. It is made from steel grades U7, U7A, U8 and U8A.

Marking compass used for drawing circles, dividing angles and applying linear dimensions to the workpiece.

3. Main types of locksmith operations.

Chopping– a metalworking operation, during which excess layers of metal are removed from the workpiece using cutting and impact tools, grooves and grooves are cut out, or the workpiece is divided into parts. The cutting tools are a chisel and a crosspiece, and the impact tool is a hammer.

cutting is the operation of separating metals and other materials into parts. Depending on the shape and size of the workpieces, cutting is carried out with a hand hacksaw, hand or lever scissors.

Hand saw consists of a steel solid or sliding frame and a hacksaw blade, which is inserted into the slots of the heads and secured with pins. A handle is attached to the shank of the fixed head. A movable head with a screw and a wing nut serves to tension the hacksaw blade. The cutting part of a hacksaw is a hacksaw blade (a narrow and thin plate with teeth on one of the ribs), made of steel grades U10A, 9ХС, Р9, Р18 and hardened. Use hacksaw blades with a length (distance between holes) of 250-300 mm. The teeth of the blade are spread (bent) so that the width of the cut is slightly larger than the thickness of the blade.

Metal straightening– an operation in which unevenness, dents, curvature, warping, waviness and other defects in materials, workpieces and parts are eliminated. Editing in most cases is a preparatory operation. Straightening has the same purpose as straightening, but defects are corrected in hardened parts.

bending widely used to give workpieces a certain shape in the manufacture of parts. For straightening and bending manually, straightening plates, straightening headstocks, anvils, vices, mandrels, sledgehammers, metal and wooden hammers (mallets) and special devices are used.

Riveting- a metalworking operation of connecting two or more parts with rivets. Riveted connections are permanent and are used in the manufacture of various metal structures.

Riveting is performed in a cold or hot (if the rivet diameter is more than 10 mm) state. The advantage of hot riveting is that the rod better fills the holes in the parts being joined, and when cooled, the rivet tightens them better. When riveting in a hot state, the diameter of the rivet should be 0.5...1 mm smaller than the hole, and in a cold state - 0.1 mm.

Manual riveting is done with a hammer; its weight is selected depending on the diameter of the rivet, for example, for rivets with a diameter of 3...3.5 mm, a hammer weighing 200 g is required.

Filing– a metalworking operation in which a layer of metal is cut off from the surface of a part with files to obtain the required shape, size and surface roughness, to fit parts during assembly and prepare edges for welding.

Files are steel (steel grades U13, U13A; ШХ13 and 13Х) hardened bars of various profiles with teeth cut on the working surfaces. The file teeth, which have a cross-sectional shape of a sharpened wedge, cut off layers of metal in the form of shavings (sawdust) from the workpiece.

Scraping is the operation of scraping thin layers of metal from the surface of a part with a cutting tool - scraper. This is the final processing of precision surfaces (guide frames of machine tools, control plates, plain bearings, etc.) to ensure a tight fit. The scrapers are made from steels U10 and U12A, their cutting ends are hardened without tempering to a hardness of HRC 64...66.

Lapping and finishing– operations of surface treatment with especially fine-grained abrasive materials using laps.

These operations achieve not only the required shape, but also the highest accuracy (5...6th quality), as well as the lowest surface roughness (up to 0.05 microns).

Fitting and assembly work– these are installation and dismantling work performed during the assembly and repair of machines. The various connections of parts made during machine assembly are divided into two main types: movable and fixed. When performing plumbing and assembly work, a variety of tools and devices are used: wrenches (simple, socket, sliding, etc.), screwdrivers, drifts, pullers, devices for pressing and pressing.

Marking is the operation of applying lines to the workpiece being processed that define the contours of the part or processing location. Markings on the workpiece are made in accordance with the drawing of the finished part.

Depending on the marking operations performed, various marking tools and devices are used.

Blanks are installed on the marking plate for drawing contour lines and places to be processed. Marking plates are cast from cast iron and have a carefully machined surface. The workpieces are installed on the slab using special jacks and linings. For ease of use of the stove and to protect its treated surface from damage, the stove is periodically wiped with graphite powder, and after completion of work it is covered with a wooden case.

In fig. 415 shows a marking plate mounted on a stable wooden stand.

A scriber is a tool used to draw lines on a workpiece to be marked. The scriber is made of hardened steel wire in the form of a thick needle, one end of which is bent at an angle of 90°; both ends of the needle are pointed. For ease of use, a thickening is made in the middle of the needle (Fig. 416, a).

The punch is used to make recesses on the workpiece in places to be drilled and on marking lines for better visibility. The center punch is made from hardened carbon steel; its shape is cylindrical, one end is pointed at an angle of 60°, the other end is blunt (Fig. 416, b). During operation, the punch is installed with its sharp end normal to the surface of the workpiece; the blunt end is struck with a hammer.

Using a thicknesser, lines are drawn on the workpiece to be marked. The thicknesser consists of a stand with a vertical stand; a clamp with a scriber fixed in it moves along the stand (Fig. 416, b). To make it easier to install the scriber at a certain height, divisions can be applied to the thicknesser stand. Thicknessers that have racks with divisions marked on them are called gauge thicknessers (Fig. 416, d).

The marking square is used to draw a vertical line; its short side has a T-section, which ensures the stability of the square on the marking plate (Fig. 417, a).

Malka is used to draw lines at the required angle; The malka consists of two steel rulers connected by a hinge (Fig. 417, b).

Marking compasses are used to draw circles on marked workpieces; its device is shown in Fig. 417, v.

A center finder is used to find the center on cylindrical workpieces (Fig. 417, d). The center finder is a square to which a ruler is attached, one of the sides of which divides the corner of the square in half. The square is brought into contact with its sides with a cylindrical workpiece; with this installation of the center finder, its ruler divides the circumference of the end of the workpiece in half. After moving the ruler to an arbitrary angle, draw a second line along the ruler. The intersection point of the lines drawn at the first and second position of the ruler determines the position of the center of the workpiece circle.

Chopping produced using a chisel or cross-section. In fig. 418, and a drawing of a chisel is given, and in Fig. 418, b - drawing of the crossmeisel. As can be seen from these drawings, the crossmeisel differs from the chisel in the shape of the working head. The sharpening angle a of the chisel and crosspiece decreases with decreasing hardness of the metal being processed; its value falls within the range of 70-45°.

The chisel is used in all trimming operations with the exception of cutting out nests, keyways, etc., which are performed with a cross-cut tool.

Chisels and crosspieces are made of carbon steel.

Cutting with a chisel or cross-cutting tool is carried out by striking them with a plumber's hammer.

The product to be cut is clamped in a bench vice. There are vices

chair (Fig. 419, a) and parallel (Fig. 419, b).

cutting During metalworking, metal is produced with a hacksaw or scissors. A hacksaw consists of a hacksaw blade and a machine.

Hacksaw blades are made from steel strips 200-300 mm long, 11-16 mm wide and 0.5-0.8 mm thick: 5-12 teeth are cut over a length of 1 cm. A manual hacksaw is used for cutting materials of small diameters; when cutting workpieces of large diameters, powered hacksaws are used. Scissors are used to cut sheet material up to 5 mm thick.

Filing called a metalworking operation used to obtain a smooth surface of a part after chopping or cutting. Filing is done with files. Files are made from steel strips with teeth cut on them (manually with a chisel or using a special gear cutting machine). After notching, the files are subjected to hardening or carburization, followed by heat treatment. Files are made in various profiles and sizes.

According to OST 320-325, the length of files is 100-450 mm with a width of 4-45 mm. In fig. 420 shows the main types of files. Depending on the nature of the filing operation and the material being processed, Various types files.

For processing babbitt, lead, leather, wood, etc., rasps are used (Fig. 420, 9), having 2-6 notches per 1 linear line. cm.

For rough stripping of metals, bars are used (Fig. 420, 1), having 4-6 notches per 1 linear line. cm.

For rough filing, hog files are used (Fig. 420, 2); number of notches 5-12 per 1 cm.

For finishing filing, semi-file (Fig. 420, 3 and 4) and personal (Fig. 420, 5) files are used with the number of notches for the first 12-18 and for the second 18-26 per 1 running line. cm.

For final finishing and precision work, velvet files (Fig. 420, 6 and 7) with a number of notches of 26-40 are used.

For sawing out shaped holes and for minor work, needle files are used (Fig. 420, 8) with a number of notches of 50-80 per 1 cm in length.

The quality of filing work depends on the correct use of the file. One of the main requirements for working with a file is to ensure that the movement of the file is parallel to the surface being processed. The position of the mechanic's hands when working correctly with files is shown in Fig. 421, where a - work with a bastard file, b - with a velvet file.

Manual drilling. Drilling is the operation of making holes in the material being processed. The tool by which this operation is performed is called a drill. Drills are divided into feather drills (Fig. 422, a) and spiral drills (Fig. 422, b).

The cutting edges of the feather drill form an angle of 90° or more. The angle between the rear edge of the drill and the machined plane, i.e. the rear angle, is made 10-25°. To reduce the cutting angle to 70-80°, a groove is cut out on the front edge.

Feather drills are simple and cheap to manufacture: the end of the rod is pulled back and forged into a blade shape, then hardened and sharpened.

Their disadvantage is the inaccuracy of processing, in particular, due to the deviation of the drill axis from the axis of rotation. In addition, when working with a feather drill, chips clog the resulting hole and spoil it, which makes it necessary to periodically interrupt work to remove chips.

A twist drill is a round rod with two helical flutes. The grooves serve to remove chips. The angle of inclination of the helical flute to the axis in normal drills is 30°. Narrow strips called ribbons or chamfers are made on the cylindrical surface of the drill along the helical grooves.

A twist drill consists of a working part 1 (Fig. 422, b, c) and a shank 4. The shank is used to secure the drill and has a cylindrical or conical shape; At the end there is a foot 5.

The working part of the drill has helical grooves and a cutting part 2, which is a cone with two cutting edges.

There are ribbons 3 along the screw grooves of the drill. The cutting part of the drill (Fig. 422, c) has a rear surface 1, a bridge 2, a cutting edge 3, a groove 4, a chamfer 5.

When working with twist drills, the holes are more regular and clean than when working with a feather drill. When working with twist drills, chips are collected and discharged automatically by screw grooves. Twist drills can be re-sharpened without changing their diameter.

The disadvantage of twist drills is that they are difficult to manufacture. Sharpening twist drills should be done using templates.

The operation of processing holes found in cast and forged workpieces or obtained by drilling is called countersinking. Countersinking is carried out in order to increase the diameter of the hole and is carried out with a countersink. A small countersink (up to 35 mm) is made solid (Fig. 423, a) and differs from an ordinary drill in a large number of grooves (usually four) and a blunt end. Large countersinks are made mounted (Fig. 423, b), for operation they are mounted on a mandrel made of machine-made steel. To process the exit part of the holes, specially shaped countersinks are used - countersinks; in fig. 423, c shows a countersink used for countersinking holes for the conical head of a bolt.

Bringing the drilled holes to the exact size is done using reamers (Fig. 423, d). Reamers differ from countersinks in a large number of grooves.

When working with drills, various types of devices are used: ratchets, hand and mechanical drills (Fig. 424, a, b and c).

When processing steel parts, the drill is cooled with oil or soapy water; Bronze and gray cast iron are drilled without the use of coolants, since when processing these materials, small chips are formed, which, together with the liquid, turn into a very viscous mass, which greatly increases friction.

Threading. A tool used in plumbing for cutting threads in holes is called a tap.

A tap is a screw with several grooves along its axis, forming cutting edges. Taps can be cylindrical or conical. The tap device is shown in Fig. 425; the thread formed by the tap is determined by the thread profile of the tap, the angle a of this profile, the pitch S, the outer diameter D, the inner diameter D1. Bench taps are used in sets of 3 pieces: roughing, semi-finishing and

stand. The first serves to pre-form the cut, the second deepens the cut made with a roughing tap, and the third finishes the thread.

The roughing tap has a thread with cut off tips, the semi-finishing tap has a less cut thread, and the finishing tap has a full thread. Threading is done with a tap in a pre-drilled hole. The diameter of this hole should be slightly smaller than the internal diameter of the thread. During operation, the tap is screwed in one turn, after which it is given half a turn in the opposite direction; This technique achieves chip crushing and makes the work easier in general.

To obtain a cleaner thread surface in steel products, taps are lubricated with oil (sulphurized or vegetable); When cutting threads in cast iron and bronze products, no lubricant is used.

Dies are used to cut threads on rods.

Dies are round or square plates with a central hole with a thread; To form cutting edges, slots are made in the cutting. The arrangement of round dies is shown in Fig. 426, a, dies for oblique dieheads, consisting of two halves, - in Fig. 426, b. When cutting threads, the dies are secured in a special device called a clamp (Fig. 426, c).

The die consists of a frame in which the dies are secured with a screw clamp. The klupp has two handles that rotate it.

To cut threads on rods of small diameter, screw boards are used, which are a hardened steel tile with threaded holes cut in it (Fig. 426, d); it has a handle to rotate the screw board.

Scraping called oneration of obtaining very clean surfaces by removing a thin layer of metal from them by scraping; the tool used for this purpose is called a scraper. The scrapers can be straight or curved, and their cross-sections can be flat, triangular or rounded. In fig. 427, and various scrapers are shown, and in FIG. 427, b - position of the scraper during operation.

The scraping process is carried out as follows: 1) before scraping, a thin layer of paint (red lead, soot, whitewash) is applied to the surface plate; 2) the surface to be treated is placed on a slab and slightly moved along it, as a result, a layer of paint adheres to the elevations of the surface to be treated, while other places remain clean; 3) the painted areas are treated with a scraper. This operation is repeated until the paint evenly covers the entire surface to be treated. Then the paint is removed from the surface plate, the plate is wiped dry and the product is moved along the surface plate; in this case, the elevated areas of the products are indicated by light spots. The quality of scraping is judged by the number of such spots per 1 cm 2 of the surface being treated; treatment is considered good if the number of spots is 5-6 per 1 cm2.

The scraping process is very labor-intensive. To mechanize it, special devices are used that significantly increase productivity and make the worker’s work easier. In fig. 428 shows a scraping machine.

Many defects of machines supplied to repair plants are well studied and systematized in standard repair technology. This technology has been developed for most tractors, combines and agricultural machines. It indicates methods for restoring parts, the tools used for this, technical specifications for repaired parts. However, it is simply impossible to foresee all cases that may occur in repair practice. Sometimes the necessary tool or material may not be available, sometimes it becomes possible to use a simpler and more reliable method of repair.

A repairman must be a generalist. In addition to the ability to perform all general metalworking operations, he must know the rules for disassembly and assembly work, have a good understanding of drawings of parts and machine components, designations of tolerances and fits, know the basic mechanical properties of metals and other repair materials, and have an idea of ​​the repair process.

1. Technological process of repair

The technological process of machine repair consists of a number of sequential operations that differ from one another in the nature of the work performed and the equipment used. However, many repair operations are similar to each other. To perform the same type of technological operations, repair enterprises organize special workplaces. They are equipped with machines, stands, fixtures, devices and other equipment for disassembling, restoring parts and assembling machines and their components.

The main element of the technological process is an operation performed at one workplace and covering all actions of the working (or working) and equipment used on one or more jointly processed, disassembled or assembled products. In addition to technological ones, in repair production there are also auxiliary operations: transport, washing, quality control, labeling, etc. Technological operations are divided into transitions, passages and techniques.

Transition is a part of an operation characterized by the unchanged surface being processed (or mating surfaces during assembly), the tool used and the operating modes of the equipment.

Passage is the part of the transition in which one layer of material is removed.

A technique is a complete set of individual movements of a worker in the process of performing an operation (for example, when drilling a hole in a product, the techniques will be: securing the product on the machine table, turning on cr.li;, bringing the drill to the product, turning on the feed, turning off the feed, retracting the spindle, turning off machine, release of the product). A wide variety of work in repair production conditions requires the mechanic to perform operations of the most varied nature, complexity and accuracy. The quality of repair operations is directly related to the qualifications of workers and equipment repair companies equipment, devices and tools. A novice repairman needs first of all to study the tool that he will have to use and master the techniques of performing general metalworking operations.

1.1.Basic plumbing operations

The main general metalworking operations include: marking, chopping and cutting, straightening and bending, filing, drilling and reaming holes. Some of them, such as marking products and drilling holes, are performed by a mechanic at shared work places specially equipped for this purpose, and the rest - at his individual work place, where he also cuts threads, scrapes, and solders.

Rational organization the mechanic's workplace allows for the highest productivity, good quality and safe working conditions with the least expenditure of effort, time and money. It is important to properly equip the workplace and maintain the established order in it once and for all.

www.autoezda.com

Basic plumbing operations - Other

Basic locksmith operations

EAT. Muravyov, Metalworking, Moscow, “Enlightenment” 1990, pp. 43-94

Basic locksmith operations

marking, cutting, straightening and bending of metals, metal cutting, filing, drilling, countersinking, countersinking and reaming of holes, threading, riveting, lapping and finishing, soldering

Workplace – metalworking workbench

A workplace is usually called a specific area of ​​the workshop intended for performing a specific job.

Fishnets are removable wooden gratings installed on top of the deck.

A clamp is also called a screw clamp

Chair vice.

The advantages are simplicity of design and high strength. The disadvantage is that the working surfaces of the jaws are not parallel in all positions

Rotary parallel vice.

The advantage is the ability to clamp the part more tightly. In addition, you can fix it at a certain angle.

Hand vices are used to secure small parts or workpieces that are inconvenient or dangerous to hold with your hands.

Marking tool

The operation of applying small dots-indentations on the surface of a part is called. The point, axis of symmetry or plane from which all dimensions on a part are measured is called a marking base

Marking

The operation of drawing lines and points on a workpiece intended for processing is called marking. Marking consists of drawing lines (scores) on the surface of the workpiece, which, according to the drawing, determine the contours of the part or the area to be processed.

Scribblers are used to apply lines (scores) to the marked surface of the workpiece.

Punch punches are used to make recesses (cores) on pre-marked lines.

Marking (metalwork) compasses are used for marking circles and arcs, dividing circles and segments into parts and other geometric constructions when marking workpieces.

Calipers

Calipers are a measuring (measuring) tool used in plumbing to take and transfer the dimensions of a part to scale

Goniometers

Used to measure angular values

Measuring tool

Measuring ruler is used for rough measurements

Editing and bending

Straightening is the operation of returning curved or bent metal products to their original straight or other shape. Giving metal a certain configuration without changing its cross-section and processing the metal by cutting is called flexible thin sheet metal is produced with a mallet. For parts that are bent at right angles without rounding on the inside, the bending allowance of the workpiece should be 0.6 ... 0.8 of the metal thickness.

Metal cutting

A percussion instrument consisting of a metal head, handle and wedge is called a hammer.

Metal cutting

Chopping is used to remove (cut down) metal irregularities from the workpiece, remove hard crust, scale, sharp edges of the part, cut out grooves and grooves, and cut sheet metal into pieces.

To cut out profile (cutting) semicircular, dihedral, etc. grooves, special cross-cutting tools are used - groovers that differ from each other in the shape of the cutting edge.

Metal cutting

Hand scissors - the simplest tool for cutting metal

Punchers (perforations)

A metalworking tool that is used to punch holes in sheet or strip metal or non-metallic materials with a thickness of not more than 4 mm

Pipe cutters

Cutting steel pipes relatively large diameters is a labor-intensive operation, so special pipe cutters are used to perform it.

Metal filing

Filing is the process of removing allowance with files, needle files and rasps.

Sharpening machine

Drilling, countersinking, countersinking and reaming of holes

Drilling consists of producing and processing holes by cutting using a special tool - a drill.

3e the upper surfaces of the hole are processed by forging in order to obtain chamfers or cylindrical recesses, for example, for the countersunk head of a screw or rivet.

Countersinking is used to process holes made by casting, stamping or drilling to give them a strict cylindrical shape, increasing the accuracy and quality of the surface.

Scraping

Scraping

The process of obtaining the accuracy of shapes, sizes and relative positions of surfaces required by operating conditions to ensure their tight fit or tightness of the connection

Lapping

Removal of the thinnest layers of metal using fine-grained abrasive powders in a lubricant environment or diamond pastes applied to the surface of the tool is called.

Vernier tools are used to make accurate measurements. Vernier tools include calipers, calipers, caliper depth gauges, and calipers.

There are calipers three types ShchTs-I, Shchts-II, Shchts-III. The divisions marked on the bottom of the caliper slide are called vernier.

Linear measurement

Micrometers

Micrometer

A universal instrument (device) designed for measuring linear dimensions by the absolute or relative contact method in the area of ​​small sizes with low error (from 2 μm to 50 μm depending on the measured ranges and accuracy class), the conversion mechanism of which is a microscrew-nut pair.

Micrometer scale

Micrometric instruments allow measurements with an error of up to

0.01 mm (6.035)

Diametric expansion of pipe ends outward in order to obtain a tight and durable press connection between pipe ends and holes.

Soldering is the process of creating a permanent connection between metals using a filler binder material

Tinning - coating the surface of metal products with a thin layer of tin or a tin-based alloy

Threading

Types of thread

Metric thread - with pitch and basic thread parameters in millimeters and a profile angle at the apex of 60°.

Inch thread - with the main thread parameters in inches, pitch in the number of threads per inch and a profile angle at the apex of 55°.

Pipe thread - with basic thread parameters in inches, pitch in the number of threads per inch and a profile angle at the apex of 55°, intended for connecting pipes, fittings and structural elements with pipe threads.

Dial indicator

multiurok.ru

Basic locksmith operations.

Profession of a locksmith.

Mechanical work is usually understood as work performed with hand and mechanized tools and completing the manufacture of most products through fitting and finishing work, connecting various parts into Assembly units, kits and complexes and their adjustments.

Assembly mechanics assemble various machines and mechanisms. Maintenance and their repairs during operation are carried out by repairmen. Toolmakers provide production with the necessary tools, facilitate and improve machining. Mechanics who install equipment, instruments, and communications securely install them in the proper place, supply various types of energy and the basic and auxiliary materials necessary for production. All these workers have in common the ability to perform various metalworking operations. They learn this in a general locksmith course.

The degree and type of professional training, the availability of knowledge, skills and abilities and suitability to perform work of a certain content and complexity determine the qualifications of the worker. It is assessed by a tariff category, which is assigned to the worker by a qualification commission. The reason for this is qualification characteristics given in special tariff and qualification directories. It states what a worker “must be able to do” and what “must know” to obtain the appropriate tariff category according to your specialty.

Basic locksmith operations.

Let's look at the basic metalworking operations using the example of processing simple parts - a guide key (Fig. 1). As shown in the drawing, the entire surface of the key is processed; it has three holes: two stepped for fastening screws and one with a thread.

The key is made from keyed steel - a rod of rectangular cross-section. To obtain a workpiece of the required length, markings are made - using a scriber, lines are applied to the surface of the circle that determine the shape and dimensions of the part. Next, the workpiece is separated with a chisel (the operation is usually called chopping) or a hacksaw (cutting). During the cutting process, the workpiece must be bent. She needs to be straightened out. Often it is necessary to do the opposite work: bend an existing workpiece, give it a complex shape. Then bending is done.

With the above operations it is impossible to obtain the correct shape of the surfaces of the part and the specified dimensions. Οʜᴎ are preliminary, preparatory. Their purpose is to prepare the workpiece for subsequent processing, ensure and speed it up by removing large layers of metal. To give the key the desired shape and size, the blank is cast. A hole ø 11 mm and for an M10 thread is obtained by drilling, and local expansion of the hole size to ø 17 mm is obtained by countersinking. The thread in the drilled hole is cut with a tap. When the hole must have exact dimensions, it is reamed. Except

considered, there are other operations: sawing and fitting - producing holes of complex shapes and very precise processing of two parts being connected; scraping and lapping are precise final operations that ensure high precision and tight connections; riveting, soldering and gluing are operations that allow you to connect parts together to form permanent connections.

As can be seen from the above, all operations for the manufacture of any product must be carried out in a certain

sequences. Together they make up the technological process of processing the part.

referatwork.ru

Basic locksmith operations.

Locksmith department.

Report in practice.

Equipment for a mechanic's workplace.

In locksmith workshops and areas there is equipment for individual and common use. Equipment for individual use are workbenches with vices. General use equipment includes: drilling and sharpening machines, marking and testing plates, straightening plate, screw press, lever scissors.

The vice is used to install and secure workpieces in a position convenient for processing.

The working tools of a mechanic are divided into:

· Manual.

· Mechanized.

A typical set of hand tools for plumbing work is divided into four groups:

1) cutting tools - files, hacksaws, chisels, drills, taps, dies, scrapers, reamers, abrasive tools;

2) auxiliary tools - hammers, cores, bits, scribers, compasses, cranks, die holders;

3) plumbing tools - wrenches, screwdrivers, pliers, hand vices, clamps, pullers;

4) measuring and control tools - rulers, calipers, bore gauges, calipers, micrometers, squares, protractors.

Basic locksmith operations.

The following basic locksmith operations are distinguished:

Marking is the application of marking lines to the workpiece or surface of the material intended for the day the workpiece was received.

Editing - unevenness, curvature, bending, and shape defects in workpieces are eliminated.

Straightening is the elimination of unevenness in a sheet or warping of a workpiece that has been hardened.

Bending - a workpiece or part thereof is given a curved shape.

Chopping - removing an excess layer of metal or cutting a workpiece into pieces using a cutting tool.

Cutting.

Sawing - processing of holes, grooves and grooves.

Fitting is the processing of one part according to another in order to connect them.

Fitting is the exact mutual fit of parts.

Lapping - finishing of parts working in pairs to ensure the best contact of working surfaces,

Riveting is a type of assembly that involves the formation of a permanent connection of two or more parts using rivets.

Soldering is a type of metalworking used to form a permanent joint using a molten intermediate material or alloy called solder.

Tinning is coating the surface of metal parts with a thin layer of molten tin.

Thread cutting.

mybiblioteka.su - 2015-2018. (0.005 sec.)

mybiblioteka.su

Topic 1.1. Basic metalworking operations and their characteristics.

Match the image with the processing type and tool

Please format your answer as follows: 1-3-5

Topic 1.5. Tolerances and fits and technical measurements

Task 1 Name the main parts of a caliper

Fill the table

Task2 Name the main parts of a micrometer

Fill the table

Task3 Read the micrometer readings.

Task 4 Consider the diagrams of tolerance fields. Determine shaft tolerance, holes, fit type.

	Tolerance field diagram		Hole tolerance		Shaft tolerance		Fit type
1		1	0,052	1	0,040	1	With a gap
2		2	0,046	2	0,019	2
3		3	0,030	3	0,032	3	Transitional
4		4	0,040	4	0,025	4	With interference

Topic 1.2. Basic metalworking operations and their characteristics.

Test by plumbing

Choose the correct answer

What is markup:

1.The operation of applying lines and points to the workpiece intended for processing

2.Operation to remove the metal layer from the workpiece

3. The operation of applying a protective layer to the part. The operation of removing burrs from the part.

Choose the correct answer

Name the types of markup:

1.There are two types: straight and angular

2.There are two types: planar and spatial

3.There is one type: basic

4.There are three types: circular, square and parallel

Choose the correct answer

Name the tool used for marking:

1. File, needle file, rasp

2.Drill, countersink, countersink, counterbore

3. Pipe cutter, hacksaw, scissors

4. Scribbler, hammer, rectangle, center punch, marking compass

Choose the correct answer

Name the measuring instruments used for marking:

1. Scale ruler, caliper, square, gage

2. Micrometer, indicator, thread template, probe

3. Scribbler, hammer, rectangle, center punch, marking compass

4. Mallet, smoother, sledgehammer, round hammer

Choose the correct answer

Based on what the parts are marked:

1.Produced based on personal experience

2.Produced based on drawing

3. Produced based on the advice of a colleague

4.Produced on the basis of a defective part

Choose the correct answer

What is nakernivapie:

1.This is an operation to apply indentation points on the surface of a part.

2.This is an operation to remove burrs from the surface of a part.

3.This is a square hole sawing operation

4.This is an operation to straighten warped metal

Choose the correct answer

Tools used for cutting metal:

1.Applicable: tap, die, die

2.Used: punch, scraper, countersink, mallet, smoother

3.Applicable: hacksaw, pipe cutter, metal scissors

4.Applicable: bench chisel, krenzmeisel, groover, hammer

Choose the correct answer

What is metal straightening:

1.Operation to straighten bent or warped metal, only ductile materials are exposed

2.Operation to form a cylindrical hole in a solid material

3.Operation to form a threaded surface on a rod

4. The operation of removing a layer of metal from a workpiece in order to give it the desired shape and size

Choose the correct answer

Name the methods for straightening metal:

1.Editing by twisting, breaking and extrusion

2.Editing by pressing, bending and crimping

3. Editing by tightening, twisting and flaring

4.Editing by bending, stretching and smoothing

Choose the correct answer

Name the tools and devices used when editing:

1.Applicable: parallel vice, chair vice, clamps

2.Applicable: stretching, crimping, support, embossing

3.Used: leveling plate, straightening head, mallet, hammer, smoother.

4. Used: punch, scraper, countersink, mallet, smoother

Choose the correct answer

What is metal cutting:

1.This is an operation involving the separation of materials into parts using a cutting tool

2. This is an operation that involves applying marking lines to the surface of the workpiece

3. This is an operation to form a threaded surface inside the hole

4. This is an operation to form a thread on the surface of a metal rod

Choose the correct answer

Name a hand tool for cutting metal:

1. Chisel, crossmeisel, groover

2.Hacksaw, hand scissors, pipe cutter

3. Smoothing iron, mallet, sledgehammer,

4.Reamer, counterbore, countersink

Choose the correct answer

What is filing:

1.Operation to remove the broken saw blade from the cut site on the surface of the workpiece

2.The operation of sawing a workpiece or part into pieces

3. The operation of removing a layer of metal from the surface of the workpiece using a cutting tool - a file

4.Operation to remove metal filings from the surface of a workpiece or part

Choose the correct answer

What tools are used when filing:

1.Used: pliers, round nose pliers, wire cutters

2.Applicable: round hammer, square hammer

3.Used: flat scraper, chisel, mallet

4.Used: files, needle files, rasps

Choose the correct answer

Name the types of file cuts:

1.Triangular, pitted, square, oval

2.Linear, parallel, perpendicular, angular

3.Drawn, impact, planed, persistent

4.Single, double cross, arc, rasp

Choose the correct answer

How many classes are files divided into depending on the number of notches per 10 mm of length:

1.Divided into 7 classes

2.Divided into 6 classes

3.Divided into 5 classes

4.Divided into 8 classes

Choose the correct answer

Name the cross-sectional shapes of a file:

1. Flat, square, triangular, round, semicircular, rhombic, hacksaw

2. Oval, triangular, tetrahedral, forked, straight, hexagonal

3. Bilateral, trilateral, universal, specialized

4. Ordinary, professional, semi-professional

Choose the correct answer

What is drilling:

1. This is an operation to form through or blind square holes in a solid material using a cutting tool - a drill

2. This is an operation to form through or blind oval holes in a solid material using a cutting tool - a drill

3. This is an operation to form through or blind triangular holes in a solid material using a cutting tool - a drill

4. This is an operation to form through or blind cylindrical holes in a solid material using a cutting tool - a drill

Choose the correct answer

Name the types of drills:

1. Triangular, square, straight, corner

2. Hacksaw, hand, machine, machine-hand

3. Spiral, feather, centering, ring, gun

4. Self-sharpening, basic, trapezoidal, thrust

Choose the correct answer

Name the types of shanks for a twist drill:

1. Oval and parallel

2. Cylindrical and conical

3. Semicircular and external

4. Special and regular

Choose the correct answer

What is a drill:

1. A cutting tool used to cut a workpiece into pieces

2. Cutting tool used to form cylindrical holes

3. Cutting tool used for soldering

4. Cutting tool used to cut threads

Choose the correct answer

Name a hand drilling tool:

1. Drill, reamer, countersink, counterbore

2. Bench drill press, vertical drill press, radial drill press

3. Hand drill, brace, ratchet, electric and pneumatic drills

4. Lapping, scraper, frame, holder

Choose the correct answer

What is called stationary drilling equipment:

1. Such equipment is equipment that is transferred from one workpiece or part to another

2. Such equipment is called equipment that runs on electric current

3. Such equipment is called equipment located in one place, while the workpiece being processed is delivered to it

4. This type of equipment is called compressed air equipment.

Choose the correct answer

Name the types of drilling machines:

1. Suspended, floor and diagonal

2. Tabletop, vertical and radial

3. Screw-cutting, boring and slotting machines

4. Manual, machine and machine

Choose the correct answer

What is countersinking:

1. This is an operation associated with the processing of a previously drilled, stamped, cast and other hole in order to give it a more regular square shape and higher accuracy

2. This is an operation associated with the processing of a previously drilled, stamped, cast and other hole in order to give it a more regular triangular shape, higher accuracy and higher roughness

3. This is an operation associated with the processing of a previously drilled, stamped, cast and other hole in order to give it a more regular oval shape, lower accuracy and lower roughness

4. This is an operation associated with the processing of a previously drilled, stamped, cast and other hole in order to give it a more regular geometric shape, higher accuracy and lower roughness

Choose the correct answer

Name the types of countersinks:

1. Pointed and blunt-nosed

2. Machine and manual

3. On stone and concrete

4. Solid and mounted

Choose the correct answer

What is deployed:

1. This is a threaded hole processing operation

2. This is an operation to process a previously drilled hole with a high degree of accuracy

3. This is a square hole processing operation with a high degree of precision

4. This is a conical hole machining operation with a high degree of precision

Choose the correct answer

Name the types of scans according to the method of use:

1. Basic and auxiliary

2. Manual and machine

3. Machine and metalworking

4. Straight and conical

Choose the correct answer

Name the types of developments in the form of the working part:

2. Rhombic and semicircular

3. Tetrahedral and triangular

4. Straight and conical

Choose the correct answer

Name the types of sweeps based on processing accuracy:

1. Cylindrical and conical

2. Roughing and finishing

3. High-quality and low-quality

4. Manual and machine

Choose the correct answer

Name the thread profiles:

1. Triangular, rectangular, trapezoidal, thrust, round

2. Oval, parabolic, three-dimensional, overlapping, serrated

3. Semicircular, mortise, heavy-duty, anti-friction

4. Modular, segmental, tubular, countersunk

Choose the correct answer

Name the thread systems:

1. Centimeter, foot, battery

2. Gas, decimeter, calibrated

3. Metric, inch, tube

4. Millimeter, water, gas

Choose the correct answer

Name the thread elements:

1. Tooth profile, outside corner, middle corner, inside corner

2. Profile angle, thread pitch, outer diameter, diameter, inner diameter

3. Tooth, module, outer radius, middle radius, inner radius

4. Tooth pitch, module angle, outer profile, middle profile, inner profile

Choose the correct answer

Name the tool for cutting internal threads:

1. Kreutzmeisel

Choose the correct answer

Name the tool for cutting external threads:

1. Countersink

2. Counterbore

Choose the correct answer

Name the types of dies:

1. Round, square (sliding), thread rolling

2. Hexagonal, spherical, end

3. Resistant, alloy, hardened

4. Modular segmental, profile

Choose the correct answer

What is sawing:

1. Type of filing

2. Type of lapping

3. A type of scraping

4. Type of fitting

Choose the correct answer

What is fitting:

1. This is a metalworking operation for mutual adjustment of cutting methods for two mating parts

2. This is a metalworking operation for mutual fitting by scraping two mating parts

3. This is a metalworking operation for mutual fitting by grinding in two mating parts

4. This is a metalworking operation for mutual fitting by filing two mating parts

Choose the correct answer

What is scraping:

1. This is a final metalworking operation consisting of scraping very thin layers of metal from the surface of the workpiece using a cutting tool - a lap.

2. This is a final metalworking operation that involves scraping very thin layers of metal from the surface of the workpiece using a cutting tool - a scraper.

3. This is a final metalworking operation consisting of scraping very thin layers of metal from the surface of the workpiece using a cutting tool - a needle file.

4. This is the final metalworking operation, which consists of scraping very thin layers of metal from the surface of the workpiece using a cutting tool - a rasp.

Choose the correct answer

Name the types of scrapers based on the shape of the cutting edge:

1. Single-sided, double-sided, three-sided

2. Flat, triangular, shaped

3. Modular, profile, segment

4. Steel, cast iron, brass

Choose the right one

Name the types of scrapers by design:

1. Riveted and welded

2. Pin and wedge

3. One-piece and composite

4. Keyed and cottered

Practical work.

Practical lesson No. 33

studopedia.net

Marking.

Mechanic's workplace.

studlib.info

Main types of locksmith operations

Marking.

Mechanic's workplace.

Topic 25. Basics of plumbing.

1. Locksmith work is the manual processing of materials, fitting of parts, assembly and repair of various mechanisms and machines.

A workplace is a part of the production area with all the equipment, tools and materials located on it that are used by a worker or a team of workers to complete a production task.

The workplace must occupy the area necessary for the rational placement of equipment and the free movement of the mechanic during work. The distance from the workbench and shelving to the mechanic should be such that he can use predominantly hand movements and, if possible, avoid turning and bending the body. The workplace should have good individual lighting.

A workbench (Fig. 36) is the main equipment of the workplace. It is a stable metal or wooden table, the lid (tabletop) of which is made from boards 50...60 mm thick of hard wood and covered with sheet iron. Single-seat workbenches are the most convenient and common, since on multi-seat workbenches, when several people work simultaneously, the quality of precision work is reduced.

Rice. 36 Single bench:

1 – frame; 2 – table top; 3 – vice; 4 – protective screen; 5 – tablet for drawings; 6 – lamp; 7 – shelf for tools; 8 – tablet for working tools; 9 – boxes; 10 – shelves; 11 – seat

The tools necessary to complete the task are placed on the workbench. The drawings are placed on a tablet, and the measuring instruments are placed on the shelves.

Under the workbench tabletop there are drawers, divided into a number of cells for storing tools and documentation.

To secure the workpieces, a vice is installed on the workbench. Depending on the nature of the work, parallel, chair and hand vices are used. The most widely used are parallel rotary and fixed vices, in which the jaws remain parallel when opened. The rotating part of the vice is connected to the base with a center bolt, around which it can be rotated to any angle and secured in the required position using a handle. To increase the service life of the vice, steel overhead jaws are attached to the working parts of the jaws. Chair vices are rarely used, only for work involving impact loads (for chopping, riveting, etc.). When processing small parts, a hand vice is used.

Selecting the height of the vice according to the height of the worker and rational placement of the tool on the workbench contribute to better development of skills, increased productivity and reduced fatigue.

When choosing the height of the vice installation, the left hand bent at the elbow is placed on the jaws of the vice so that the ends of the straightened fingers of the hand touch the chin. Tools and devices are placed so that they can be conveniently taken with the appropriate hand: what is taken with the right hand is held on the right, what is taken with the left is held on the left.

A protective screen made of metal mesh or durable plexiglass is installed on the workbench to contain pieces of metal flying off during chopping.

Blanks, finished parts and fixtures are placed on racks installed in the area allocated for them.

2. Marking is the operation of applying lines (scores) to the workpiece, defining (according to the drawing) the contours of the part and the places to be processed. Marking is used for individual and small-scale production.

Markings are carried out on marking plates cast from gray cast iron, aged and precisely machined.

Lines (marks) for planar markings are applied with a scriber, for spatial markings - with a scriber fixed in the clamp of the planer. Scribblers are made from steel grades U10 and U12, their working ends are hardened and sharpened.

The center punch is designed for making recesses (cores) on pre-marked lines. It is made from steel grades U7, U7A, U8 and U8A.

The marking compass is used for drawing circles, dividing angles and applying linear dimensions to the workpiece.

3. Main types of locksmith operations.

Chopping is a metalworking operation in which excess layers of metal are removed from a workpiece using a cutting and impact tool, grooves and grooves are cut out, or the workpiece is divided into parts. The cutting tools are a chisel and a crosspiece, and the impact tool is a hammer.

Cutting is the operation of separating metals and other materials into parts. Depending on the shape and size of the workpieces, cutting is carried out with a hand hacksaw, hand or lever scissors.

A hand hacksaw consists of a steel solid or sliding frame and a hacksaw blade, which is inserted into the slots of the heads and secured with pins. A handle is attached to the shank of the fixed head. A movable head with a screw and a wing nut serves to tension the hacksaw blade. The cutting part of a hacksaw is a hacksaw blade (a narrow and thin plate with teeth on one of the ribs), made of steel grades U10A, 9ХС, Р9, Р18 and hardened. Use hacksaw blades with a length (distance between holes) of 250-300 mm. The teeth of the blade are spread (bent) so that the width of the cut is slightly larger than the thickness of the blade.

Metal straightening is an operation in which unevenness, dents, curvature, warping, waviness and other defects in materials, workpieces and parts are eliminated. Editing in most cases is a preparatory operation. Straightening has the same purpose as straightening, but defects are corrected in hardened parts.

Bending is widely used to give workpieces a certain shape in the manufacture of parts. For straightening and bending manually, straightening plates, straightening headstocks, anvils, vices, mandrels, sledgehammers, metal and wooden hammers (mallets) and special devices are used.

Riveting is a metalworking operation of joining two or more parts with rivets. Riveted connections are permanent and are used in the manufacture of various metal structures.

Riveting is performed in a cold or hot (if the rivet diameter is more than 10 mm) state. The advantage of hot riveting is that the rod better fills the holes in the parts being joined, and when cooled, the rivet tightens them better. When riveting in a hot state, the diameter of the rivet should be 0.5...1 mm smaller than the hole, and in a cold state - 0.1 mm.

Manual riveting is done with a hammer; its weight is selected depending on the diameter of the rivet, for example, for rivets with a diameter of 3...3.5 mm, a hammer weighing 200 g is required.

Filing is a metalworking operation in which a layer of metal is cut off from the surface of a part with files to obtain the required shape, size and surface roughness, to fit parts during assembly and prepare edges for welding.

Files are steel (steel grades U13, U13A; ШХ13 and 13Х) hardened bars of various profiles with teeth cut on the working surfaces. The file teeth, which have a cross-sectional shape of a sharpened wedge, cut off layers of metal in the form of shavings (sawdust) from the workpiece.

Scraping is the operation of scraping thin layers of metal from the surface of a part with a cutting tool - a scraper. This is the final processing of precision surfaces (guide frames of machine tools, control plates, plain bearings, etc.) to ensure a tight fit. The scrapers are made from steels U10 and U12A, their cutting ends are hardened without tempering to a hardness of HRC 64...66.

Lapping and finishing are operations of surface treatment with especially fine-grained abrasive materials using laps.

These operations achieve not only the required shape, but also the highest accuracy (5...6th quality), as well as the lowest surface roughness (up to 0.05 microns).

Fitting and assembly work is installation and dismantling work performed during the assembly and repair of machines. The various connections of parts made during machine assembly are divided into two main types: movable and fixed. When performing plumbing and assembly work, a variety of tools and devices are used: wrenches (simple, socket, sliding, etc.), screwdrivers, drifts, pullers, devices for pressing and pressing.

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://allbest.ru

INTRODUCTION

The name of the profession "locksmith" is of German origin. Locksmith (in German "Schlosser" from Schloss - lock) skilled workers in metal processing, assembling machinery and equipment and performing other metal work, a profession widespread in all industries National economy. There are mechanics: toolmakers, patternmakers, assemblers, repairers of machine tools, cars, oil and gas refining equipment, equipment, plumbers, etc. Mechanics perform a variety of metal processing work, usually complementing machining or completing the manufacture of metal products, assembling machines and mechanisms, as well as adjusting them. . Vices, clamps, clamps, pliers are used as fastening and clamping tools; for assembling permanent joints - riveting hammers, riveting machines, supports, roller mills, soldering irons, blowtorches; for assembling threaded connections - wrenches, screwdrivers, stud drivers, fittings ; control, measuring and marking tools used in plumbing include compasses, bore gauges, thickness gauges, measuring rulers, tape measures, probes, calipers, gauges, micrometers, thread gauges, squares, inclinometers, levels, straight edges, calibration plates, etc. With the development of technology and production technology, manual processing metal is gradually being replaced by machine. In the beginning, machine maintenance was carried out by people, and then it became automated. On modern stage The operation of machines is controlled using computers that operate according to a predetermined program and are capable of independently readjusting them when operating conditions change. The profession of a mechanic has not lost its importance modern enterprise. At the zero construction cycle of the enterprise, plumbers and electricians work, laying energy routes. The building of the enterprise is erected by metal structure mechanics. After construction, the equipment arriving at the enterprise is installed by fitters, and then by fitters. Each of these groups of mechanics is characterized by knowledge and professional skills specific to their work. However, the main basis for every locksmith is mastery of general locksmith operations.

1. FITTING WORKS

1.1 Planar marking of metal

Planar marking is the application of lines to the surface of the material being processed, indicating the boundaries to which the material must be processed, as well as lines defining the centers of future holes. Lines with punched indentations applied to the surface of the material are called marking marks. All subsequent processing of the material is carried out using marking marks: cutting, filing, drilling, etc. Planar marking is one of the most critical operations, since the accuracy of further processing depends on the quality of its implementation. The accuracy of planar marking is low and ranges from 0.2 to 0.5 mm. Planar marking is widely used in individual and small-scale production. In serial and mass production, planar markings are used mainly in the manufacture of technological equipment (stamps, templates, fixtures, etc.), as well as in the manufacture of various parts intended for equipment repair. Planar marking is a labor-intensive operation. Therefore, where possible and rational, they try not to use planar markings. However, processing materials without markings requires the use of various devices (stops, templates, jigs, etc.). It is known that the cost of each device pays off only when manufactured in large quantities parts identical in shape and size, this can only be done in serial and mass production. In individual and small-scale production, when producing single parts, it is more profitable to produce them using markings than to produce this or that device. When performing coppersmith and tinsmithing work, many parts are made without the use of planar markings. Sheet shears with inclined knives equipped with back and side stops are used to cut sheet material without markings into rectangular, square, trapezoidal and oblique-shaped parts. Profiles are bent on edge bending machines without markings, i.e., along the stop available on the machine. The use of jigs and templates allows you to drill holes in parts without first marking them. When making planar markings, both the coppersmith and the tinsmith have to perform various geometric constructions: draw parallel and perpendicular lines, divide straight lines into equal parts, construct angles, divide angles and circles into equal parts, draw conjugate lines, etc. These geometric coppersmiths and tinsmiths must be able to make constructions quickly and accurately, for which it is necessary to know the basics of technical drawing. The coppersmith and tinsmith have to make products of various shapes from sheet and profile material. For the manufacture of products, blanks of appropriate shape and size are required. To find the actual dimensions of such workpieces, you must be able to calculate the surface area of ​​​​the products and draw their developments. These developments are obtained by planar marking. Planar marking is carried out depending on production conditions by several methods: according to a drawing, template, sample and on site. When performing planar markings, safety regulations must be observed. To avoid cutting your hands with the edges of the sheet material when laying it on the marking table, as well as when removing it from the table, after marking is completed, gloves are put on your hands. When using prisms and pads, measures are taken to prevent them from falling. It is recommended to put protective rubber caps on the ends of scribers and compasses that are temporarily not in use.

1.2 Straightening, metal bending

Metal straightening is an operation to remove defects on workpieces and parts in the form of convexity, concavity, warping, waviness, curvature, etc. The meaning of metal straightening is to expand the concave part of the metal and compress the convex surface of the metal. The metal is straightened both in a heated state and in a cold state. The choice of one or another type of editing depends on the size of the cuts, deflection and material of the part.

Metalworking using this method can be either manual (on a cast iron or steel plate) or machine (on presses or rollers). The correct slab should be massive. Its dimensions should be from 400x400 mm. or up to 1500X1500 mm. The slabs are installed on wooden or metal stands, which provide good stability and horizontal position. For straightening of hardened parts (straightening), straightening headstocks are used. They are made of steel and are hardened before use. The working surface of the headstock itself can be spherical or cylindrical with a radius of 100-200 mm. (see photo) Manual straightening of metal is done with special hammers with an insert, radius, round striker made of soft metal. Thin sheet metal is most often straightened with a mallet. When straightening metal, it is very important to choose the right place where to strike, and the force of the strike must be measured against the amount of curvature and changed as it moves to the best state.

Types of metals that have a twisted bend are processed using the unwinding method. Round metals can be trimmed on an anvil or slab. If the twist has several bends, then straightening should begin from the edges, and then process the bends in the middle. The most difficult thing in this type is straightening sheet metal. This type of metal must be placed on the slab with the curve or convex side up. The blows must be applied towards the convexity (bend) from the edges of the sheet. Under the influence of impacts, the convex part of the sheet will straighten, and the flat part will be stretched. When straightening hardened sheet metal, not strong but frequent blows are applied with a hammer, directed from the concavity to the edges. The part is straightened and the upper parts of the metal are stretched.

Large cross-section round and shaft workpieces are processed using a hydraulic or screw process. By the nature and methods of work, metal straightening is very easy to compare with another type of metal processing - this is the process of bending metals. Metal bending is used to give the workpiece a shape according to the drawing. Its meaning is that one of the parts of the workpiece is bent towards the other at a certain angle. The deformation of the part must be plastic, and the bending stress must have a lower characteristic compared to the elastic limit, because if you use further changes in the structure of the part, for example, cutting metal, it will be difficult. In this case, the workpiece will retain its shape after the end of the loading process. Manual bending is done in a vice, using a hammer and other devices. The sequence of metal bending depends on the material and the contour of the workpiece. Bending of sheet metal is done with a mallet. When using various mandrels for metals, the shape of the mandrels must correspond to the shape of the part, taking into account the deformation of the metal. When bending a workpiece, you need to set its dimensions correctly. The length of the workpiece is determined according to the drawing, taking into account all the bends on the workpiece. For parts that bend without rounding from the inside and at right angles, the bending allowance of the part should be from 0.5 to 0.8 mm of metal thickness.

During plastic deformation of a part during the bending process, the elasticity of the materials must be taken into account: the bending angle increases slightly after the load is removed. After the load is removed, the part can be processed different ways one of them is metal cutting. Manufacturing and metalworking of parts with a very small bend radius can lead to rupture of the outer layer of the workpiece. The size of the minimum bending radius on metal completely depends on the properties of the metal, the quality of the workpieces and their bending technology. Parts with a small bending radius must be made from plastic materials.

Sometimes during the manufacture of products there is a need to obtain curved pipes bent at ordinary angles. Bending can be done on welded and seamlessly drawn pipes, as well as pipes made of alloys and non-ferrous metals. Pipe bending is done with a filler (most often river sand), but the process is possible without it. In this case, it depends on the diameter, its bending radius, and the material of the pipe. Filler, i.e. sand prevents the walls of the pipe from forming wrinkles and bending folds. By cutting metal pipes, they are given the required form and sizes.

1.3 Metal cutting

Chopping is a metalworking operation in which, using a cutting tool (chisel), excess layers of metal are removed from a workpiece or part or the workpiece is cut into pieces.

At modern ways processing of material or workpieces, metal cutting is an auxiliary operation.

Metal cutting is carried out in a vice, on a plate and on an anvil using a metalworker's hammer, a chisel, a cross-cutting tool, a blacksmith's chisel and a sledgehammer.

Metal cutting can be horizontal or vertical depending on the location of the chisel during the operation. Horizontal cutting is done in a vice. In this case, the rear edge of the chisel is installed to the plane of the vise jaws almost horizontally, at an angle of no more than 5°. Vertical cutting is done on a slab or anvil. The chisel is installed vertically, and the material to be cut is laid horizontally on the slab.

For metal cutting, hammers weighing 400, 500, 600 and 800 g are used. The hammers are mounted on handles made of hard and tough wood (birch, maple, oak, rowan). Handles should be oval in shape, with a smooth and clean surface, without knots or cracks. The length of the handle of a hammer weighing 400-600 g is 350 mm, and weighing 800 g is 380-450 mm. To prevent the hammer from jumping off during operation, the end of the handle on which the hammer is mounted is wedged with wooden or metal wedges 1-3 mm thick. The wedges are placed along the major axis of the handle section. Wooden wedges are placed on glue, and metal ones are roughed up so that they do not fall out.

The working part of the chisel and the crosspiece is hardened to a length of at least 30 mm, and the head is hardened weaker than the blade (about 15-25 mm in length) so that when struck with a hammer it does not crumble or crack.

The rest of the chisel and crosspiece should remain soft. Chisels and crosspieces should not have cracks, caps or other defects.

The most commonly used chisels are 175 and 200 mm long with blades

20 and 25 mm wide. To cut grooves in steel and cast iron, cross-cutting tools 150--175 mm long with a blade 5--10 mm wide are used. The heads of the chisel and crosspiece are forged to a cone, which ensures the correct direction of the hammer blow and reduces the possibility of a mushroom cap forming on the head.

The sharpening angle of chisels and crossbars depends on the hardness of the metal being processed. For chopping cast iron, hard steel and hard bronze, the sharpening angle of the tool is 70°, for chopping medium and soft steel - 60°, for chopping brass, copper and zinc - 45°, for chopping very soft metals (aluminum, lead) - - 35--45°.

Tools are sharpened on sharpening machines with abrasive wheels. During sharpening, the working part of the tool (blade) becomes very hot and may become loose. During tempering, the hardness of the hardening is lost and the tool becomes unsuitable for further work. To avoid this, the working part of the tool is cooled with water during sharpening. Figure 6 shows how to hold the chisel when sharpening and how to check that the angle is sharpened correctly.

The productivity and cleanliness of metal cutting depend on the correct working methods. When chopping, you need to stand steadily and straight, half-turned towards the vice. The hammer is supposed to be held by the handle at a distance of 15-20 mm from the end and applied strong blows to the center of the chisel head. You should look at the chisel blade, not at its head, otherwise the chisel blade will not go properly. The chisel should be kept at a distance of 20-25 mm from the head.

Workpieces made of sheet or section steel can be cut in a vice at the level of the jaws or at marks above the level of the jaws of the vice.

When chopping at the level of the jaws of the vice, the workpiece is clamped firmly in the vice so that the upper edge protrudes above the jaws by 3-4 mm and the first chips are cut down along the entire length of the workpiece. Then the workpiece is rearranged in a vice so that the upper edge protrudes 3-4 mm above the level of the vice jaws, and the second chip is cut off. This is how the product is sequentially cut to the required size.

When cutting above the level of the vise jaws along the marks, the workpiece is clamped in the vice so that the marked mark is above the level of the vice jaws and parallel to them. The cutting is carried out according to the marked marks sequentially, as when cutting according to the level of the jaws of the vice. When chopping, the chisel blade should be positioned at an angle of 45° to the metal being cut, and the head should be raised upward at an angle of 25-40°. With this arrangement of the chisel, the cutting line will be smooth and cutting will be done faster.

A large layer of metal on a wide plane of the workpiece is cut down as follows: the workpiece is clamped in a vice, a chamfer is cut off with a chisel, transverse grooves are cut with a cross-section, and then the protruding edges are cut off with a chisel. When cutting grooves with a cross-section, the thickness of the chips should be no more than 1 mm, and when cutting off protruding edges with a chisel, it should be from 1 to 2 mm.

The strip steel is cut on a slab or anvil (9). First, cut lines are drawn on both sides of the strip with chalk. Then, having laid the strip on the anvil, set the chisel vertically on the marked mark and, with strong blows of the bench hammer, cut the strip to half its thickness. Then the strip is turned over, cut on the other side and the part to be cut off is broken off.

Round metal is cut in the same way, with the rod turning after each blow. Having cut the rod along the entire circumference to a sufficient depth, break off the part to be cut off.

Carbon and alloy structural steel up to 20-25 mm thick can be cut cold on a plate or anvil using forge chisels and sledgehammers. To do this, on -t*“ or, Four sides of the workpiece are marked with chalk cutting lines. Then the metal is laid on the anvil, the forging chisel is installed vertically on the marking line and the metal is cut along this entire line to the required depth with strong blows of the sledgehammer, gradually moving the chisel. The metal is also cut on the other side or on all four sides, after which the part to be cut off is broken off. To speed up and simplify felling, an auxiliary tool is used - nizhiik (cutting). The undercut with the shank is inserted into the square hole of the anvil, then the workpiece is placed on the undercut, and a forge chisel is installed on top, as shown in 10, D, and the chisel is struck with a sledgehammer. In this way, the metal is simultaneously cut on both sides with a chisel and undercut.

Cast iron pipes are cut with a chisel on wooden supports. First, a cutting line is marked along the circumference of the pipe with chalk, and then, placing linings under the pipe, in two or three passes they cut the pipe with a chisel along the marking line (I, a), gradually turning it. After checking the depth of the cut groove, which should be at least 73 times the thickness of the pipe wall, a part of the pipe is separated with light blows of a hammer. When working, the chisel must be held perpendicular to the axis of the pipe. The end of the pipe at the cut point must be smooth, perpendicular to the axis of the pipe and coincide with the intended cut line. The correctness of the end is checked by eye and controlled with a square.

More productive is mechanized cutting of metal with a pneumatic hammer operating under the influence of compressed air at a pressure of 5-6 kgf/cm2. Compressed air is supplied to the hammer through hoses from the compressor. A pneumatic hammer consists of a cylinder into which a chisel is inserted, a piston moving in the cylinder, and an air distribution device. Thanks to the air distribution device, the piston receives forward and return movement and quickly moves back and forth along the cylinder. During forward movement, the piston hits the chisel, which cuts the metal. The hammer is put into operation by pressing trigger 6. The worker holds the hammer with both hands and directs the chisel to the cutting site.

A manual screw press is used for cutting cast iron sewer pipes with a diameter of 50 and 100 mm. It consists of a welded frame 2, two side posts 5, which have threaded necks in the upper part, onto which a crossbeam 6 is mounted. The crossbeam is attached to the posts with nuts. On the traverse with a nut and screw. In the lower part of the racks there is a lower fixed cage with an insertable lower knife, and in the upper part of the racks there is an upper movable cage 3 with an insertable upper knife. The upper movable cage is fastened to the lead screw with a plate 12 and bolts 4 and rises and falls together with them. Side posts 5 are guides for the upper frame. A channel with posts at the ends is welded to the bottom of the frame plate. This channel is a guiding element when laying the pipe for cutting.

The knives are attached to the clips with bolts. The internal diameters of the knife blades should be 2 mm smaller than the external diameters of the pipes being cut. For each pipe diameter there is a pair of knives and a pair of rollers installed on the channel to feed pipes to the knives.

The press works as follows. First, knives and rollers are installed in accordance with the diameter of the pipes being cut. Having raised the upper holder with the knife using the flywheel, lay the pipe on the rollers so that the cutting line coincides with the tip of the lower knife. Then, with a sharp jerk, turn the flywheel in the opposite direction, while lowering the lead screw with the upper knife. From the sharp pressure of the lower and upper knives, a cut first appears on the sides of the pipe, the pipe wedges and then splits into two parts. The press is serviced by one worker.

The VMS-36A mechanism operates on the principle of a drive press. A gearbox with two heads 2 is mounted on the welded frame of the mechanism. One head is designed for cutting pipes with a diameter of 50 mm, the second for pipes with a diameter of 100 mm. The pipes are cut by four movable knives mounted in the chucks of the mechanism heads. The mechanism is powered by a 1.5 kW electric motor with a rotation speed of 1420 rpm. The engine is started using a foot pedal.

To cut pipes, first turn on the electric motor. Then they take a pre-marked pipe and lay it on supports so that the marking line on the pipe coincides with the knife blade. After this, press the pedal with your foot. The knives are lowered onto the pipe, which is cut along the marking line by the pressure of the knives. After chopping, the knives return to their original position and the operation of the head automatically stops. The pipe cutting time for one cycle is 3 s. Each of the four knives covers the pipe being cut at a length equal to a quarter of its circumference. Figure 15 shows the planes of cutting knives, the geometry of which takes into account the characteristics of the material being cut, i.e., the fragility of cast iron. To prevent destruction and ensure a smooth and even cutting surface of the pipe being cut, the cutting edges of the knives are made intermittent due to cut transverse grooves. The radius of the circle formed by the cutting edges of the knives must be less than the outer radius of the pipe being cut. The blade sharpening angle is 60°. The cutting process occurs as follows.

When approaching, the knives first touch the pipe at eight points. As they approach further, they crash into the pipe; holes are formed, located around the circumference. Microcracks appear near the holes, directed from hole to hole and deep into the metal. During the process, microcracks merge and running cracks are formed in the same direction, which advance the feed of the knives. This causes one end of the pipe to separate from the other.

Using knives of the described design, rings 20 mm long can be cut from cast iron sewer pipes.

When chopping, in order to avoid bruises and injuries, the following precautions must be observed: firmly place the hammer or sledgehammer on the handle; securely strengthen the metal in a vice and, when chopping on an anvil, support the part of the workpiece being chopped off; use fencing nets when cutting hard or brittle metal so that flying fragments do not injure the person working or who is nearby; work with working tools and on working machines;

When cutting pipes on a press, wear gloves. Before cutting pipes, it is necessary to check the serviceability of the mechanism, electrical equipment and protective fences.

1.4 Metal cutting

During metalworking and procurement work, metal is cut in cases where it is necessary to separate a part of a certain size or a given shape from a workpiece of sectional, shaped steel or pipes. This operation differs from chopping in that it is performed not by impact, but by pressing forces, and the adjacent torns of the main and separated parts of the metal have straight planes without bevels. Strip, round, angle or other steel is cut in a vice, and pipes are cut in a clamp using hand hacksaws.

Metal is cut with hand and mechanized hacksaws.

Hand hacksaws are used sliding with a horizontal or inclined handle. Hacksaws with a horizontal handle consist of a left frame 3 and a right frame 5, a frame 4 and a handle 7. The hacksaw blade is inserted into the slots of the head/tension screw and the head 6 of the shank. They are firmly secured with pins and tightened with a thumb 2. The hacksaw can be extended to different lengths according to the length of the hacksaw blade.

For hand hacksaws, hacksaw blades with a length of 300 mm, a width of 15 mm and a thickness of 0.8 mm are used. The sharpening angle of the hacksaw blade tooth is 60°; both hacksaw blades are moved apart so that the blade does not get stuck in the metal slot. The lower part of the blades with teeth is hardened, and the upper part is left unhardened, which reduces the breakage of hacksaw blades during operation.

When cutting metals of unequal hardness, hacksaw blades with teeth of different sizes are used. For cutting soft metals, blades with 16 teeth per 25 mm blade length are used, for more hard metals(ornamental or tool well-annealed steel) - with 19 teeth, for hard metals (cast iron, tool steel) - with 22 teeth per 25 mm length. To cut thin strip and small angle steel, blades with 22 teeth per 22 mm of blade length are used, so that at least two or three teeth are placed across the thickness of the metal. With a larger tooth, the blades break.

The blades are inserted into hacksaws with the teeth forward. The cutting blade should not be stretched too tightly, otherwise it will break during operation.

When working, the hacksaw is held with both hands: with the right hand, by the handle, and with the left, the second end of the hacksaw is supported and a reciprocating movement is made. The position of the hacksaw when working should be closer to horizontal, so that the pressure of the worker on both ends of the hacksaw is more uniform.

When cutting, the metal is secured in a vice, and the pipes are secured in a clamp so that the cutting line is located close to the jaws of the vice or to the clamp. With this fastening, the material does not vibrate during cutting, the hacksaw blade does not break, and the cutting line is smooth. When cutting wide material, the hacksaw is held horizontally, and when cutting strip or shaped steel pipes, it is held slightly obliquely. The forward working stroke of the hacksaw is made with pressure, and the reverse (idle) stroke is made without pressure. The force of pressure depends on the hardness of the metal.

When cutting shaped and strip steel, do not press the blade very hard to avoid jamming and breaking it. At the end of cutting, you need to support the free end of the material and bring the cutting to completion. Otherwise, the material may break, pinching and breakage of the canvas. The end of the material will be uneven.

To increase labor productivity and proper organization the workplace should: prepare in advance the required number of hacksaw blades; Pre-mark the entire batch of metal to be cut and place it on the workbench on the left side of the vice; Place the material to be cut in a certain place at the workbench according to size.

When working with a hacksaw, you must follow the following safety rules: firmly fasten the handle to the shank so that it does not come off during operation and the tip of the shank does not injure your hand; The metal being cut must be firmly secured in a vice so that it does not fall out when cutting with a hacksaw and does not hurt the worker’s leg; Sweep away sawdust from the workbench with a brush.

A manual mechanized hacksaw is more productive than an ordinary one. An electric motor is mounted in the housing 6 of the hacksaw, on the shaft of which a drum having a spiral groove is mounted. A pin fits into the drum groove. When the electric motor shaft and drum rotate, the slider and the hacksaw blade attached to it move. A bar is used to support the hacksaw blade when cutting metal.

When cutting pipes manually, as mentioned above, they are secured in clamps.

Clamps can be double-column or single-column. Double-column clamps are more convenient, as they allow you to slightly lift the clamping prism, turn the screw to remove the pin from the holes, fold back the upper part of the clamp and easily remove the pipe from it to the side.

To clamp steel pipes and pipe blanks with a diameter of 15-50 mm, pneumatic clamps of various designs are used.

Diaphragm pneumatic clamp VMS-DP-1 consists of a body, jaws with guides, steel levers (two large and two small), a flat diaphragm, a rod and a return spring. One or two layers are used as a diaphragm sheet rubber(depending on its thickness).

The pipes are clamped by supplying compressed air to the drive with a working pressure of 4 kgf/cm2. The pipe is released using a spring after compressed air is released into the atmosphere.

The force of the return spring, i.e., the opening of the jaws, is adjusted with a round nut screwed into the lower part of the pneumatic chamber body.

Pneumatic clamps are used in pipe procurement shops of assembly plants when assembling assembly units.

The 872A driven hacksaw machine is designed for cutting various workpieces from section and profile metal of round and square sections. The machine bed in the upper part forms a table on which a vice is installed to strengthen the material being cut. The machine is equipped with two types of vices: with parallel jaws, in which rectangular-shaped material is strengthened, and jaws with V-shaped cuts, in which round-shaped material is strengthened. A vice with parallel jaws rotates around an axis, which makes it possible to fasten the material being cut into it at different angles (up to 45°) to the hacksaw blade.

At the top of the machine there is a trunk, which can be lowered and raised using the frame raising and lowering cylinder. The saw frame 5 with a hacksaw blade attached to it moves along the trunk guides. The frame is driven into reciprocating motion by a crank mechanism consisting of a crank and connecting rod. The hacksaw machine is driven by an electric motor 10 connected to the crank shaft by a gear transmission.

Due to the mass of the frame, the blade presses on the material being cut. Cutting occurs only when the hacksaw blade moves forward. During the reverse stroke, the trunk with the hacksaw blade is slightly raised under the action of the oil piston pump; Thanks to this, the cutting teeth become less dull.

The machine is operated as follows. First, mark the cutting line on the metal or pipe being cut with chalk, then they are strengthened in the vice of the machine so that the cutting line coincides with the hacksaw blade. After this, the machine is turned on and the metal is cut.

To increase the productivity of the machine, small-sized long steel and small-diameter pipes are placed in the machine’s vice in packages of 8-14 pieces, depending on their size and cross-section, and each package is cut entirely. When cutting, the hacksaw blade is cooled by an emulsion supplied by a pump. The emulsion contains 10 l

water, 1 kg liquid soap and 0.5 kg of drying oil. Before use, the mixture is thoroughly mixed and boiled. Disadvantages of a driven hacksaw machine: its low productivity and rapid wear of hacksaw blades.

When working on a drive machine, you must follow the following safety rules: work only on a working machine; support the cut part of the material with special stands or hands so that it does not fall on your feet; Monitor the serviceability of the electrical wiring, switch and electric motor to prevent electric shock.

Driven press shears S-229A are designed for cutting long, shaped and sheet steel up to 13 mm thick. In addition, they are used for punching round holes with a diameter of up to 20 mm with a material thickness of up to 15 mm and stamping small parts.

The machine bed 8 is mounted on a trolley 7, through which the shear press can be transported from place to place. Unit 6 for cutting sheet steel consists of a lower fixed knife, an upper movable knife and a stop, with the help of which the material to be cut is pressed against the lower knife. Unit 5 for cutting steels of different profiles consists of two vertical knives having holes that correspond to different steel profiles. The machine operates from an electric motor 3 through a drive 4.

Sheet or strip steel is placed on the lower knife, pressed with a stop and, turning on the mechanism of the lower knife, it is cut. The design of the press shears allows you to cut metal of any length. Punching of holes and stamping is carried out on the hole-punching 2 and die-cutting / devices by pressing the machine switch lever.

Driven combination shear presses are portable, easy to use and suitable for work in open areas and in procurement workshops.

When working with press shears, you must follow the following safety rules: start work only if there are protective covers on the moving parts, checking the grounding of the electric motor housing; Before starting work, lubricate the shear presses and check their operation at idle speed; work with installed stops for the material; when placing the processed material into the press shears, keep your hands at a safe distance from the knives and punch; remove small stamped parts only using pullers, hooks or tongs; Do not lubricate gears and other moving parts when the electric motor is running and when cutting material.

The VMS-32 pipe cutting mechanism is designed for cutting steel water and gas pipes with a diameter of 15-50 mm. Diameter 160 mm. The gearbox is rotated using a tension screw and a steering wheel. Cutting disc rotation speed 193 rpm. The VMS-32 mechanism is driven by a 1.1 kW electric motor connected to the gearbox shaft by an elastic coupling. The cutting disk of the VMS-32 mechanism must have a regular cylindrical shape with a sharpening angle of about 60°. As the cutting blade becomes dull, it must be sharpened again. It is recommended to sharpen with a portable abrasive wheel on a flexible hose while simultaneously rotating the abrasive wheel and cutting disc. The mechanism is supplied with stands that serve as supports when cutting long pipe blanks.

The marked pipe is laid on special rollers so that the cutting line coincides with the cutting disc. Then the pipe is covered with an upper chute - a trough, it is locked with a pin and the mechanism is started. By turning the steering wheel, the cutting disc is brought closer to the pipe. The pipe rotates due to friction between it and the cutting disc. From the pressure transmitted to the rotating disk, it cuts into the metal and cuts the pipe. After cutting the pipe, by turning the steering wheel, the gearbox with the roller is moved upward.

The VMS-35 pipe cutting mechanism is designed for cutting water and gas pipes with a diameter of 15-70 mm. The pipes are cut with a cutting disc with a diameter of 160 mm, mounted on the shaft of the oscillating gearbox. When cutting, the pipe rotates. The cutting disc is fed to the pipe and returned to its original position using a pneumatic device

1.5 Metal filing

The sawn product is firmly clamped in a vice to give it a stable position.

The layer of rust and scale on the workpiece and the crust of the casting are filed off with an old bastard file so as not to spoil the good one, which quickly wears out. Then they begin roughing the part with a suitable bastard file and after that they finally process it with a personal file. In order not to damage the jaws of the vice during final filing, they are covered with linings made of copper, brass, lead or aluminum.

The cleanliness and accuracy of filing depend on the installation of the vice, the position of the worker’s body at the vice, working methods and the position of the file.

When installing a vice, the top of its jaws should be at the level of the worker’s elbow. The correct position of the worker at the vice is shown in Fig: 36. When filing, it is necessary to stand on the side of the vice - half-turned, at a distance of about 200 mm from the edge of the workbench. The body should be straight and rotated 45° to the longitudinal axis of the vice.

The legs are spaced foot-width apart, the left leg is moved slightly forward in the direction of movement of the file. The feet are placed at approximately 60° to one another. When working, the body is slightly tilted forward. This position of the body and legs provides the most comfortable and stable position for the worker; the movement of the arms becomes free.

During filing, the file is held with the right hand, resting the head of the handle in the palm. The thumb is placed on top of the handle, and the remaining fingers support the handle from below. The left hand is placed on the end of the file near his nose and presses the file. When rough filing, the palm of the left hand is placed at a distance of about 30 mm from the end of the file, with the fingers half-bent so as not to injure them on the edges of the product during work.

When finishing filing, the end of the file is held with the left hand between the thumb located at the top of the file and the remaining fingers at the bottom of the file. The file is moved back and forth smoothly along its entire length.

The product is clamped in a vice so that the sawn surface protrudes above the jaws of the vice by 5-10 mm. To avoid grooves and blockages along the edges, when moving the file forward, it is evenly pressed against the entire surface to be processed. The file is pressed only when moving it forward. When the file moves back, the pressure is released. The file movement speed is 40-60 double strokes per minute.

To obtain a properly processed surface, the product is filed with cross strokes, alternately from corner to corner. First, the surface is sawn from right to left, and then from left to right. Thus, the surface is filed until the required layer of metal is removed.

After the final filing of the first wide plane of the tile, they begin filing the opposite surface. In this case, it is necessary to obtain parallel surfaces of a given thickness. The second wide surface is filed with cross strokes.

The accuracy of surface treatment and the accuracy of angles are checked with a ruler and square, and the dimensions are checked with calipers, bore gauges, scale rulers or vernier calipers.

When preparing pipelines and manufacturing parts for sanitary systems, the ends of the pipes and the planes of the parts are filed. Defects during filing mean the removal of an excess layer of metal and a reduction in the size of the product compared to the required ones, unevenness of the filed surface and the appearance of “blockages”. During the filing process, you should use control and measuring tools and systematically check the dimensions of the parts being processed.

When filing, you must follow the following safety rules: the handle must be firmly attached to the file so that during operation it does not come off and injure your hand with the shank; the vice must be in good working order, the product must be firmly secured in it; the workbench should be firmly strengthened so that it does not swing; when filing parts with sharp edges, do not tuck your fingers under the file during its reverse stroke; The shavings may only be removed with a broom brush; After work, files must be cleaned of dirt and shavings with a wire brush; It is not recommended to place files one on top of the other, as this will damage the notch.

To mechanize filing work, hand-held electric and pneumatic tools are used, as well as filing machines with a pneumatic drive and a flexible shaft. A special device is put on the end of the flexible shaft that converts rotational motion into reciprocating motion. A file is inserted into this device, which is used to file the parts.

A pneumatic file consists of a working tool, a head for securing it, a motion converter, a gearbox and an electric motor. File stroke length 12 mm, number of double strokes per minute 1500.

1.6 Drilling, countersinking of metal

Holes are drilled according to preliminary markings made with a marking tool, or according to a template. Using a template saves time, since the contours of the holes previously marked on the template are transferred to the workpiece. Holes of large diameters are drilled in two steps - first with a drill of a smaller diameter, and then with a drill of the required diameter.

Drilling holes can be through (the drill comes out through the hole being drilled); blind (the depth of the hole is less than the thickness of the metal); for threading and reaming. The method of performing these types of drilling is the same, except for blind drilling, in which it is necessary to maintain the required hole depth. For this purpose, devices are used that limit the feed of the drill to the required depth. If there are no such devices, the machine is stopped after a certain time, the drill is removed and the depth of the hole is measured.

For accurate and fast drilling, the drill must be firmly and correctly secured in the machine spindle or in the chuck so that it rotates without wobbling. If the drill beats, the hole will be of an irregular shape, and the drill may break.

The pressure on the drill should be uniform and correspond to the hardness of the metal and the diameter of the hole. With soft metal and a small hole diameter, the rotation speed and feed are increased. When the drill comes out of the hole, the pressure should be released to avoid breaking the drill. Since the drill heats up during drilling, it should be cooled by interrupting work. When working on machines, the drill is cooled with a soap emulsion. When processing cast iron and bronze, the drill is not cooled. When drilling deep holes, you should periodically remove the drill from the hole and clear the hole and grooves in the drill from chips.

Figure 42 shows a jig for drilling holes in flanges for steel pipes. Two support strips are welded to the bottom of the jig with holes for attaching the jig to the drilling machine table. The support strips are welded to a support disk with a hole in the middle, in which the flange foot rotates freely. The heel has a central hole with a thread for a clamp bolt. A marking disk 3 is attached to the heel, on the circumference of which eight recesses are located at equal distances from one another (corresponding to the largest number of holes in the flange).

To drill holes, the flange is placed on a marking disk, strengthened by turning handle 5 and centered using cone 6.

The jig is installed on a drilling machine so that the center of the drill coincides with the circle on which the holes in the flange are located. The flange is placed on the lining. Then the disk is installed so that the latch 7 gets into the recess on the circle. After drilling the first hole, the disk is rearranged so that the latch gets into the recess for drilling the next hole.

Due to incorrect or weak fastening of parts, improper sharpening of drills, clogging of the drill groove with chips, insufficient cooling of the drill, incorrect cutting speed and drill feed, drills break. If drills are selected incorrectly, are fastened incorrectly, and work methods are incorrect, the following types of defects are possible: the hole size is larger than required, an oblique hole, the hole is offset from the intended center, the hole depth is greater than required.

When drilling on machines, the following safety rules must be followed: machines must have guards for rotating parts; the workpieces should be firmly fixed on the table, and not held by hands during processing; hand-. tie your robe tightly; do not handle the rotating cutting tool and spindle; do not remove broken cutting tools from the hole with your hands, use special devices for this; Do not lean on the machine while working.

Deployment. To obtain holes with a clean surface or to accurately fit a hole to a ground part, an operation called reaming is performed. Reaming is done manually or on a drilling machine using reamers. Manual reamers are driven into rotation by a hand crank.

Taper reamers are designed for reaming tapered holes.

For cleaner surface treatment of holes and cooling of the tool during reaming, drilled holes in steel are lubricated with mineral oil, in copper with emulsion, in aluminum with turpentine, and in brass and bronze holes are reamed without lubrication.

Drill the holes manually as follows. The part is firmly fixed in a vice. A reamer is inserted into the hole, so that the reamer axis coincides with the axis of the hole. Then they begin to rotate the knob with a sweep to the right, smoothly moving it forward. The reamer is rotated in one direction only.

Countersinking and countersinking. Countersinking is the processing of a hole produced by casting, forging or stamping to give it a cylindrical shape, the required size and a clean surface. Countersinking is an intermediate operation when processing a hole for reaming. Countersinking is done with a countersink. Countersinks are also used for processing conical and cylindrical recesses with a flat bottom.

A countersink has more cutting edges (three or four) than a twist drill and provides a cleaner hole.

The allowance for countersinking for holes with a diameter of 15 to 35 mm is given 1 -1.5 mm.

The countersinking operation is performed in the same way as reaming.

Countersinking operations are performed on a drilling machine, as is drilling holes to the required depth.

2. THREADING

metalworking marking cutting countersinking

Threading is the processing of a rod or hole in a part using a thread-cutting tool to produce an external or internal screw thread consisting of alternating spiral grooves and protrusions-turns. Cutting is performed on pipes, bolts, nuts, which are used for detachable connections of pipelines and various parts of equipment.

The main elements of a thread: profile, pitch, profile angle, depth, outer, inner and middle diameters.

The cross-sectional shape of the thread is called the thread profile. According to the thread profile, there are triangular, rectangular, trapezoidal, etc. When assembling sanitary systems and parts, only triangular threads are used.

Based on the direction of the thread turn, they are divided into right and left.

According to their purpose, threads are divided into fastening and special. Fastening threads include triangular threads, special threads include rectangular threads, etc. Triangular threads are called fastening threads because they are cut on fasteners: bolts, nuts, screws. Thread pitch 7 is the distance between the tops or bases of two adjacent turns.

The thread profile angle is the angle formed by the intersection of the lateral edges (sides) of the thread.

The thread depth is the distance from the top to the base of the thread. Outside diameter-- the distance between the tops of two opposite sides of the thread. Internal diameter is the distance between the bases of two opposite sides of the thread. Average diameter is the distance between the top of the thread and the base of the thread on the opposite side.

The relationship between the thread pitch, thread depth and the number of turns per unit thread length is as follows: the larger the thread pitch, the greater the thread depth and the smaller the number of threads (turns) per unit thread length, and vice versa.

According to the system of measures, triangular threads are divided into metric and inch. A thread that has the profile of an equilateral triangle with an apex angle of 60° is called metric. It is used in instrument making and mechanical engineering. The outer diameter of a screw or the inner diameter of a hole with a metric thread is measured in millimeters, and the thread pitch is measured in iv millimeters and fractions of a millimeter. An inch thread has the same profile as a metric thread, but the apex angle is 55°. It differs from metric threads in larger pitches; measured in inches.

When assembling sanitary parts, inch threads are used. Inch threads can be used for fastening or pipe threads. Fastening threads differ from pipe threads in that they have a larger pitch and provide a strong connection; used for cutting bolts, nuts, rods and holes. Pipe threads are used to connect pipes. It is smaller than the fastening one, since its depth is limited by the thickness of the pipe walls. Due to the larger number of threads per inch of cutting length, the density of pipe threads is significantly greater than fastening threads.

External thread cutting. External threads on bolts, screws and rods are cut by hand using dies.

Depending on the device, the dies are prismatic, sliding, or solid round.

Prismatic dies consist of two identical halves, mounted in a clamp shaped like a frame with handles. On the two outer sides of these dies there are prismatic grooves into which the prismatic protrusions of the clamp fit.

Sliding dies are installed in the die so that the numbers on the halves of the dies are opposite the corresponding numbers indicated on the frame. Otherwise the thread will be incorrect. Secure the dies with a stop screw. A steel plate-cracker is placed between the thrust screw and the die so that when pressed by the screw the die does not burst. The round die is secured in the collar-holder with two or four thrust screws.

To obtain the correct threads, it is necessary that the diameters of the rods and holes being drilled correspond to the size of the threads.

Sliding dies can be used to cut full threads with small deviations in the diameter of the rod. When cutting threads with round solid dies, deviations in the diameter of the cut rod are not allowed. With a larger diameter of the rod the thread will be smooth, with a smaller diameter it will be incomplete.

When cutting threads, the bolts are strengthened vertically in a vice.

Sliding dies cut threads in two or three passes, and round dies cut threads in one pass.

The die is rotated from left to right when cutting a right-hand thread and from right to left when cutting a left-hand thread. At 25--38 mm of working revolution, make 32--38 mm of revolution back so that the chips break more easily. When rotating, press on the die. After cutting the thread, check its correctness by screwing on the nut.

To cool dies and taps when cutting threads in steel parts, drying oil or sulfofresol is used, and when cutting threads in cast iron parts, turpentine is used. It is not recommended to use mineral oil, as it degrades the cutting quality.

Internal thread cutting. Internal threads are manually cut with taps, which are inserted into the driver. The tap has a intake part (the end of the tap), which is used for cutting threads; calibrating (middle) - for guiding when cutting and calibrating the cut hole - and tail with a square head - it holds the tap in the driver during operation.

CONCLUSION

During this training practical work I learned to use measuring tools; learned how to correctly mark parts; correctly cut metal; metal cutting; straighten and bend metal; manual filing of metal; drilling, countersinking, reaming.

LIST OF REFERENCES USED

1. Aristov A.I., et al. Metrology, standardization, certification. - M.: INFRA-M, 2012, 256 p. +CD-R.

2. Kholodkova A.G. General technology of mechanical engineering. - M.: Publishing center "Academy", 2005.-224 p.

3. Cherepakhin A.A. Materials processing technology - M.: Publishing center "Academy", 2004.-272 p.

additional literature

1. Klepikov V.V., Bodrov A.N. Mechanical engineering technology. - M.: FORUM: INFRA-M, 2004.-860 p.

2. Muradyan S.V. Organization and technology of the industry. - Rostov n/d: “Phoenix”, 2001.-448 p.

3. Ovchinnikov V.V. Fundamentals of the theory of welding and cutting of metals. - M.: KNORUS, 2012, 248 p.

4. Saltykov V.A. and others. Machines and equipment of machine-building enterprises. St. Petersburg: BHV-Petersburg, 2012, 288 p.

Posted on Allbest.ru

Similar documents

The meaning, tasks and structure of the repair service. The essence and content of the preventive maintenance system. Basic locksmith operations. Straightening and bending of metals. Drilling, countersinking and reaming of holes. Reading working drawings and sketches.

practice report, added 04/09/2015


Characteristics of the enterprise OJSC "Novorossiysk Ship Repair Plant". Contents of plumbing practice. Purpose of marking, straightening and bending of metal, lapping of metal surfaces. Safety rules when working on drilling and grinding machines.

practice report, added 09/30/2015


Features of bending workpieces from sheet metal in a vice and using mandrels, the sequence of all operations, characteristics of tools. Analysis of typical defects during metal bending. Stages of bending rectangular bracket and round metal.

presentation, added 04/16/2012


Properties of a laser beam: directionality, monochromaticity and coherence. Metal laser cutting technology. The use of auxiliary gas to remove metal destruction products. Types of lasers. Solid state laser circuit. Cutting aluminum and alloys.

laboratory work, added 06/12/2013


History of metal-cutting machines. The purpose of drilling is operations to obtain holes in various materials during their processing, the purpose of which is to make holes for threading, countersinking, and reaming. Basic types of broaching.

presentation, added 10/05/2016


Metal processing by heating (thermal cutting). Oxygen cutting process, materials used. Equipment and equipment for gas-oxygen cutting. Process mechanization and cutting quality control. Organization safe conditions labor.

course work, added 06/14/2011


Types of welding using pressure, mechanical and thermal energy. Basic parameters used in plasma processing processes. Physical principle and technology of plasma cutting of metal. Its main advantages. Scheme of a cutting plasma torch.

abstract, added 01/19/2015


Basic classifications of threads, their main parameters and features. Features of the cutting process and formation of the surface layer. The influence of the composition and structure of fiberglass plastics on their workability. Technological operations and parameters of the cutting process.

course work, added 03/13/2011


Organization of rational cutting of sheet metal, taking into account business balances in the conditions of a machine-building enterprise. Technological aspects of sheet metal cutting. Features of the technologies and equipment used. Plasma and laser cutting.

thesis, added 10/27/2017


Organization and layout of a mechanic's workplace. Storage of blanks and finished products. Box with a set of locksmith tools. Designs of marking plates. Carrying out planar marking, finishing and rough cutting, piercing. Chopping tools.

Metalworking technology contains a number of basic operations, such as marking, chopping, straightening and bending metals, cutting metals, filing, drilling, countersinking, countersinking and reaming holes, threading, riveting, lapping and finishing, soldering, etc. Most of these operations include for metal cutting processing.

3.1 Marking

Marking is the operation of applying lines (scores) to the surface of the workpiece, showing, according to the drawing, the contours of the part or place to be processed. Markup is divided into:

Linear (one-dimensional) – along the length of rods, rolled products, strip steel,

Planar (two-dimensional) – for sheet metal blanks,

Spatial (volumetric, three-dimensional) – for volumetric workpieces.

Special marking tools include scribers, center punches, marking compasses, and surface planers. In addition to these tools, hammers, marking plates and auxiliary devices are used: pads, jacks, etc.

after processing. Pattern marking is used in the production of large batches of identical parts. It is advisable because labor-intensive and time-consuming marking according to the drawing is performed only once during the manufacture of the template. All subsequent operations for marking blanks consist of copying the outlines of the template. In addition, the manufactured templates can be used to control the part after processing the workpiece.

3.2 Straightening and bending of metals

Straightening is an operation to eliminate defects in workpieces and parts in the form of concavity, convexity, waviness, warping, curvature, etc. Its essence lies in the compression of the convex layer of metal and the expansion of the concave one.

The metal is straightened both in cold and heated states. The choice of one or another straightening method depends on the amount of deflection, size and material of the workpiece (part).

Straightening can be done manually (on a steel or cast iron leveling plate) or machine (on leveling rollers or presses).

The correct slab, like the marking slab, must be massive. Its dimensions can be from 400400 mm to 15003000 mm. The slabs are installed on metal or wooden supports, ensuring the stability of the slab and its horizontal position.

To straighten hardened parts (straightening), straightening heads are used. They are made of steel and hardened. The working surface of the headstock can be cylindrical or spherical with a radius of 150-200 mm.

Manual straightening is carried out with special hammers with a round, radius or insertable soft metal striker. Thin sheet metal is straightened with a mallet (wooden hammer).

Check the edit “by eye”, and when high requirements to the straightness of the strip - with a straight edge or on a test plate.

Shafts and round workpieces of large cross-section are straightened using a manual screw or hydraulic press.

Metal bending is used to give the workpiece a curved shape according to the drawing. Its essence lies in the fact that one part of the workpiece is bent relative to the other at a given angle. Manual bending is done in a vice using a hammer and various devices.

Bending of thin sheet metal is done with a mallet.

When plastic deformation of metal occurs during bending, the elasticity of the material must be taken into account: after the load is removed, the bending angle increases slightly.

The manufacture of parts with very small bending radii is associated with the danger of rupture of the outer layer of the workpiece at the bending point. The size of the minimum permissible bend radius depends on mechanical properties workpiece material, bending technology and surface quality.

Pipe bending is done with or without filler (usually dry river sand). The filler protects the pipe walls from the formation of folds and wrinkles (corrugations) in places of bending.

studfiles.net

GBPOU RM "Saransk Polytechnic College" Ruzaevka.

Notes for the lesson “Basic plumbing operations in welding production»

File: lesson notes

Routing No. 1 PM05. “Performing work according to the worker’s profession”

Topic: General information about metalworking operations used in assembly and welding production.

Purpose: To become familiar with the basic metalworking operations used in the manufacture of a welded product.

Lesson type – practical lesson.

Lesson teaching method - partially search

Lesson objectives:

Educational:

The student must be able to:

Correctly determine the loads on welds; - draw up diagrams of loads on welds.

Educational:

To develop in students the ability to independently accept technical solutions, attentiveness, respect for the chosen profession.

Developmental:

To form in students an information-professional worldview and a desire to learn new things.

To stimulate interest in the discipline, to reveal the relationship of the discipline with other professional disciplines.

The form of training is group.

The teaching method is practical.

Material, technical and didactic equipment of the lesson: - multimedia installation, electronic textbook materials, guidelines to complete the work

During the classes

1. Updating basic knowledge, abilities, skills and personality traits

Checking the availability of students according to the payroll - report; - Setting lesson goals; - Issuing individual assignments for practical work.

2. Formation of new knowledge, abilities, skills and personality traits

Metalworking is the processing of metals, usually complementing machine machining or completing the manufacture of metal products by connecting parts by welding, assembling machines and mechanisms, as well as their adjustment. Locksmith work is performed using manual or mechanized locksmith tools or on machines.

Locksmith work is used in various types production and they are united by a single technology for their implementation.

Basic plumbing operations can be divided into several groups according to their purpose:

Fig. 1 Main groups of plumbing operations

The operations of each group have their own accuracy class, so in the process of work you should clearly understand what processing accuracy is necessary in the final result of metalworking. In enterprises or workshops that produce a variety of welded products, the versatility of performing various metalwork operations is required.

Quality welded joint largely depends on the preparation of the metal and the assembly of the product for welding.

The base metal intended for the manufacture of welded structures is cleaned, marked into individual parts, and the necessary edge profiling is performed.

Cleaning is an operation that is used to remove from the metal surface preservatives, contaminants, cutting fluids, rust, scale, burrs and burrs that complicate the welding process and cause defects. welds and preventing the application of protective coatings.

Straightening is an operation to eliminate deformations of rolled sheet steel and profile metal, straightening blanks of parts that have dents, bulges, waviness, warping, curvature, etc. The metal is straightened both in a cold and heated state. The choice of method depends on the deflection, size and material of the product.

Marking is the transfer of full-size dimensions of a part from a drawing to metal. In addition, when welding, marking lines (marks) are applied to the surface of the workpiece, which determine the installation location of individual parts when assembling components and structures.

There are:

1. Planar markings.

2. Spatial marking.

Metal cutting is the operation of separating metal into parts.

Depending on the shape and size of the workpieces or parts, cutting is carried out manually - with hand scissors, hand hacksaws, lever scissors. Cutting can also be carried out using oxygen torches along the intended contour line of the part manually or with special purpose gas cutting machines. Cutting on mechanized machines is more productive and has high quality cutting However, it is advisable to perform mechanical cutting when preparing parts of the same type, mainly with a rectangular cross-section.

Bending is a method of processing metal by pressure, in which a workpiece or part thereof is given a curved shape.

Chopping is a metalworking operation in which, using a cutting tool (chisel, etc.) and a percussion tool (machinery hammer), excess layers of metal are removed from the surface of a workpiece or part or the workpiece is cut into pieces. In addition, chopping is used when it is necessary to remove burrs, defects or remove part of the metal.

Filing is the removal of a layer of metal from the surface of a workpiece using a special cutting tool - a file.

Using files, a mechanic gives parts the required shape and size, fits parts to each other, prepares the edges of parts for welding and performs other work.

3. Summing up the lesson (5 min)

Monitoring the completion of the task by all students in the group, analyzing the performance of the work, making comments as the work progresses and obtaining specific results.

4. Homework(5 min): material from an electronic textbook on the topic, repetition of previously studied material.

xn----8sbafar2bwfctnifu9c.xn--p1ai

Basic metalworking operations and tools used

Straightening is an operation through which unevenness, curvature or other imperfections in the shape of workpieces are eliminated.

The main equipment for manual straightening of metals are steel or cast iron leveling plates. Steel hammers with a round striker are used as a tool for manual straightening; Hammers made of soft materials are used for straightening finished surfaces, as well as for straightening workpieces and parts made of non-ferrous metals and alloys.

Chopping is an operation of cold metal cutting. The impact tools for chopping are metalworking and pneumatic hammers, and the cutting tools are chisels, cross-cutters and groovers.

Chisel. The metalworking chisel is made of tool carbon steel. It consists of three parts: shock, middle and working.

The striking part is made tapering upward, and its top (the striker) is rounded; The middle part of the chisel is held during chopping; the working part is wedge-shaped. The sharpening angle is selected depending on the hardness of the material being processed.

For the most common materials, the following sharpening angles are recommended: for hard materials (hard steel, cast iron) – 70°;

for materials of medium hardness (steel) – 60°;

for soft materials (copper, brass) – 45°;

for aluminum alloys – 35°.

Kreutzmeisel. To cut out narrow grooves and grooves, use a chisel with a narrow cutting edge - a cross-section. Such a chisel can also be used to remove wide layers of metal: first, grooves are cut with a narrow chisel, and the remaining protrusions are cut off with a wide chisel.

Locksmith's hammers. Bench hammers are used for chopping metals and come in two types: with a round head and with a square head. The main characteristic of a hammer is its mass. For chopping metals, hammers weighing 400...600g are used.

To make work easier and increase productivity, mechanized tools are used. Among them, the most common is the pneumatic chipping hammer.

Metal cutting

For cutting metal, hacksaws are used, the cutting part of which is the blade. The choice of blade depends on the material of the workpiece, its shape and size. Pipe cutters are used to cut pipes manually. For cutting sheet metal up to 1.5 mm thick, straight-cut or shaped scissors are used. The wire is cut with needle-nose pliers or power scissors.

Filing

Filing is an operation in which a layer of metal is removed from the surface of the workpiece using a cutting tool - a file.

The purpose of filing is to give parts the required shape, size and specified surface roughness.

Files vary in the number of cuts, section profile and length.

According to the number of teeth cut per 10 mm of length, files are divided into 6 classes (0, 1, 2, 3, 4.5).

Depending on the work performed, files are divided into the following types: metalworking files – general purpose and for special work, machine tools, needle files and rasps.

1) General purpose metalworker’s files according to GOST 1465-69 are manufactured in eight types: flat, square, triangular, semicircular, rhombic and hacksaw with a length of 100 to 400 mm with a notch No. 0-5.

Bench files for special work are intended for removing very large allowances when filing grooves, shaped and curved surfaces; for processing non-ferrous metals, non-metallic materials, etc. Depending on the work performed, files of this type are divided into grooved, flat with oval ribs, bars, double-ended, etc.

2) Machine files according to their design are divided into rod, disk, shaped heads and lamellar. During operation, the rod file is subject to a reciprocating motion, the disc files and shaped heads are subject to rotational motion, and the plate files are subject to continuous movement along with a continuously moving metal strip.

3) Needle files according to GOST 1513-67 are manufactured in ten types: flat, triangular, square, semicircular oval, hacksaw, etc., 40, 60 and 80 mm long with a notch of 5 numbers. The length of the file is determined by the length of the working part. The edges of flat files have a single or double notch. The sides and top edge of hacksaw files have a double notch.

Needle files are used for filing small surfaces and narrow places that are inaccessible to processing with bench files.

4) Rasps, in accordance with GOST 6876-54, are manufactured in several types: general purpose, shoe and ungulate.

Depending on the profile, general purpose rasps are divided into flat, round and semicircular with notch No. 1-2 and length from 259 to 350 mm.

Hole machining

Drilling is carried out on drilling machines or using hand-held devices. The main cutting part is the drill, which has two cutting edges. When drilling holes with a diameter of more than 20 mm, pre-drill the holes with a drill of a smaller diameter, then drill it to size with a drill of a larger diameter.

After drilling, stamping, casting, they are countersinked to obtain a more accurate hole. Depending on the accuracy and purpose of the holes for their processing, countersinks of two numbers are made: No. 1 - for preliminary processing of holes and No. 2 - for final processing. Structurally, countersinks are of two types: solid, processing holes from 10 to 40 mm, and mounted ones, from 32 to 80 mm.

Reaming is used to obtain holes with a more precise shape and low roughness. The operation is carried out using a multi-bladed tool - a reamer. Depending on the shape, cylindrical and conical reamers are distinguished. By method of application - manual and machine, by design - solid, mounted, sliding (adjustable) and combined, right and left.

Manufactured part:

Part sketch:

Progress:

1. Processing the sharp corners of the workpiece with a hog file.

2. Applying markings using a caliper and a height gauge.

3. Punching along the contour of the marking for drilling.

4. Drilling.

5. Beating off excess material with a chisel.

6. Processing with files until the required dimensions are obtained.

7. Drilling out the central hole and thread. Thread cutting,

8. Polishing with sandpaper.

Welding section

infopedia.su

Plumbing operation - Great Encyclopedia of Oil and Gas, article, page 1

Locksmith operation

Page 1

Locksmith operations must be carried out very carefully, using only well-sharpened tools.

Mechanical operations performed on a conveyor are mechanized whenever possible.

Metalworking operations involve processing and fitting parts manually using simple tools and devices. For many years, locksmith operations were not mechanized and were therefore very labor intensive.

Mechanical assembly operations involve processing and fitting parts using simple tools. The need for metalworking operations is caused by imperfect machining of parts and the lack of interchangeability of parts during assembly.

The listed plumbing operations are preparatory; they are performed before assembling parts into assemblies.

An electrician performs plumbing operations for repairing electrical equipment.

An electrician performs plumbing operations for repairing electrical equipment using metalworking (Fig. 2), metal-cutting (Fig. 3) and measuring (Fig. 4) tools.

A metalworking operation is a completed part of the technological process of processing a workpiece or part, performed simultaneously and continuously before moving on to processing the next workpiece or part. The concept of metalworking operation is conditional, since the same metalworking operation, carried out at different enterprises or under different conditions, is defined differently from the point of view of the technology for its implementation.

The most common plumbing operations during pipe preparation for assembly are threading and bending.

When performing metalworking operations on processing individual parts, they must be firmly secured in a vice. The bench vise must be in full working order, firmly clamp the products, and there should be no noticeable wear on the notches on the jaws.

Many metalworking operations in electrical machines differ significantly from similar operations in mechanical engineering.

Many metalworking operations in electrical machines differ significantly from similar operations in general mechanical engineering.

The variety of metalworking operations leads to the improvement and specialization of clamping devices, some of which are shown in Fig.

Pages:      1    2    3    4

www.ngpedia.ru

- Metalwork and tool work

Metalwork and tool work

Before assembling the device, the completeness, quality of workmanship and degree of readiness of the parts received for assembly are determined. Having made sure that the parts comply with the drawing and the technological process, they begin their metalworking.

Their machining involves dulling sharp edges, removing burrs, threading threads, assembling individual units installed in assembled form, creating the required connection and smooth running of parts and units, scraping or grinding the supporting planes and planes of connection with the body of the device. Most of the listed works are performed using conventional plumbing techniques.

In many cases, the processing of hardened surfaces of parts is carried out not by the mechanical department, but by the assembly section of the workshop. The reason for this is that grinding operations, as a rule, are interspersed with metalworking operations, and sometimes carried out by the same toolmakers. The hardened surfaces of device parts are ground on machines, with mechanized tools or manually.

Grinding is carried out with abrasive wheels, heads and bars. Manual grinding with stones is carried out if the surface of the part cannot be processed on a machine. Abrasive bars are used for it various forms and sizes (GOST 2456-52), made from both artificial and natural abrasive materials. It is known that during manual grinding the cutting speed (the speed of movement of the block) is many times lower than the cutting speed when grinding on machines or mechanized tools. In this regard, abrasive bars are selected with greater hardness than grinding wheels. Manual grinding, as a rule, is carried out first with coarse-grained and hard stones, and then with fine-grained and softer stones.

During manual grinding, the surfaces of the bars quickly wear out, become greasy or lose their shape. To restore the shape and performance of the bars, they are periodically straightened on special plates coated with grinding powders. When straightening, the block is placed on the surface of the slab and moved in various directions with some pressure. After several movements along the surface of the slab, the plane of the block becomes geometrically correct, and its edges become sharp and suitable for further work.

Abrasive stones are used to grind the shaped surfaces of copiers, installations and other parts, as well as the supporting surfaces of assembled devices. Methods for obtaining shaped surfaces, precise planes and angles are similar to the techniques described earlier. However, due to the fact that the accuracy of these surfaces is coarser than the equivalent surfaces of the measuring tool, in the production of devices they rarely resort to pattern finishing, and are more often limited to polishing the surfaces with abrasive sandpaper after mechanical or manual grinding.

The largest volume of preparatory metalworking operations falls on the metalworking of the device body. As stated earlier, the base and base planes of the body are machined before it is sent for assembly. At the assembly site, these surfaces are again inspected, their correctness is checked and damage is repaired. The test is carried out “for paint” using a control plate. The main and technological bases of the building are subjected to the same check.

The accuracy of the device requires a reliable connection between the housing and the components installed on it. Therefore, their connecting surfaces are carefully processed within the range of VV 6 - WV 8 by grinding or scraping. In addition to the necessary cleanliness of the surface, these planes are required to be strictly parallel and perpendicular to the base and bases of the body.

pereosnastka.ru

Main types of locksmith operations.

Production Main types of metalworking operations.

Marking.

Mechanic's workplace.

Topic 25. Basics of plumbing.

1. Locksmith work - ϶ᴛᴏ manual processing of materials, fitting of parts, assembly and repair of various mechanisms and machines.

A workplace is a part of the production area with all the equipment, tools and materials located on it that are used by a worker or a team of workers to complete a production task.

The workplace must occupy the area necessary for the rational placement of equipment and the free movement of the mechanic during work. The distance from the workbench and shelving to the mechanic should be such that he can use predominantly hand movements and, if possible, avoid turning and bending the body. The workplace should have good individual lighting.

A workbench (Fig. 36) is the main equipment of the workplace. It is a stable metal or wooden table, the lid (tabletop) of which is made from boards 50...60 mm thick of hardwood and covered with sheet iron. Single-seat workbenches are the most convenient and common, since on multi-seat workbenches, when several people work simultaneously, the quality of precision work is reduced.

Rice. 36 Single bench:

1 – frame; 2 – table top; 3 – vice; 4 – protective screen; 5 – tablet for drawings; 6 – lamp; 7 – shelf for tools; 8 – tablet for working tools; 9 – boxes; 10 – shelves; 11 – seat

The tools necessary to complete the task are placed on the workbench. The drawings are placed on a tablet, and the measuring instruments are placed on the shelves.

Under the workbench tabletop there are drawers, divided into a number of cells for storing tools and documentation.

To secure the workpieces, a vice is installed on the workbench. Considering the dependence on the nature of the work, parallel, chair and hand vices are used. The most widely used are parallel rotary and fixed vices, in which the jaws remain parallel when opened. The rotating part of the vice is connected to the base with a center bolt, around which it can be rotated to any angle and secured in the required position using a handle. To increase the service life of the vice, steel overhead jaws are attached to the working parts of the jaws. Chair vices are rarely used, only for work involving impact loads (for chopping, riveting, etc.). When processing small parts, a hand vice is used.

Selecting the height of the vice according to the height of the worker and rational placement of the tool on the workbench contribute to better development of skills, increased productivity and reduced fatigue.

When choosing the height of the vice installation, the left hand bent at the elbow is placed on the jaws of the vice so that the ends of the straightened fingers of the hand touch the chin. Tools and devices are placed so that they can be conveniently taken with the appropriate hand: what is taken with the right hand is held on the right, what is taken with the left is held on the left.

A protective screen made of metal mesh or durable plexiglass is installed on the workbench to contain pieces of metal flying off during chopping.

Blanks, finished parts and fixtures are placed on racks installed in the area allocated for them.

2. Marking is the operation of applying lines (scores) to the workpiece, defining (according to the drawing) the contours of the part and the places to be processed. Markings are used for individual and small-scale production.

Markings are carried out on marking plates cast from gray cast iron, aged and precisely machined.

Lines (marks) for planar markings are applied with a scriber, for spatial markings - with a scriber fixed in the clamp of the planer. Scribblers are made from steel grades U10 and U12, their working ends are hardened and sharpened.

The center punch is designed for making recesses (cores) on pre-marked lines. It is made from steel grades U7, U7A, U8 and U8A.

The marking compass is used for drawing circles, dividing angles and applying linear dimensions to the workpiece.

3. Main types of locksmith operations.

Chopping is a metalworking operation in which excess layers of metal are removed from a workpiece using a cutting and impact tool, grooves and grooves are cut out, or the workpiece is divided into parts. The cutting tools are a chisel and a crosspiece, and the impact tool is a hammer.

Cutting is the operation of separating metals and other materials into parts. Taking into account the dependence on the shape and size of the workpieces, cutting is carried out with a hand hacksaw, hand or lever scissors.

A hand hacksaw consists of a steel solid or sliding frame and a hacksaw blade, which is inserted into the slots of the heads and secured with pins. A handle is attached to the shank of the fixed head. A movable head with a screw and a wing nut serves to tension the hacksaw blade. The cutting part of a hacksaw is a hacksaw blade (a narrow and thin plate with teeth on one of the ribs), made of steel grades U10A, 9ХС, Р9, Р18 and hardened. Use hacksaw blades with a length (distance between holes) of 250-300 mm. The teeth of the blade are spread (bent) so that the width of the cut is slightly larger than the thickness of the blade.

Metal straightening is an operation in which unevenness, dents, curvature, warping, waviness and other defects in materials, workpieces and parts are eliminated. Editing in most cases is a preparatory operation. Straightening has the same purpose as straightening, but defects are corrected in hardened parts.

Bending is widely used to give workpieces a certain shape in the manufacture of parts. For straightening and bending manually, straightening plates, straightening headstocks, anvils, vices, mandrels, sledgehammers, metal and wooden hammers (mallets) and special devices are used.

Riveting is a metalworking operation of connecting two or more parts with rivets. Riveted connections are permanent and are used in the manufacture of various metal structures.

Riveting is performed in a cold or hot (if the rivet diameter is more than 10 mm) state. The advantage of hot riveting is that the rod better fills the holes in the parts being joined, and when cooled, the rivet tightens them better. When riveting in a hot state, the diameter of the rivet should be 0.5...1 mm smaller than the hole, and in a cold state - 0.1 mm.

Manual riveting is performed with a hammer, its weight is selected depending on the diameter of the rivet, for example, for rivets with a diameter of 3...3.5 mm, a hammer weighing 200 ᴦ is required.

Filing is a metalworking operation in which a layer of metal is cut off from the surface of a part with files to obtain the required shape, size and surface roughness, to fit parts during assembly and prepare edges for welding.

Files are steel (steel grades U13, U13A; ШХ13 and 13Х) hardened bars of various profiles with teeth cut on the working surfaces. The file teeth, which have a cross-sectional shape of a sharpened wedge, cut off layers of metal in the form of shavings (sawdust) from the workpiece.

Scraping is usually called the operation of scraping thin layers of metal from the surface of a part with a cutting tool - a scraper. This is the final processing of precision surfaces (guide frames of machine tools, control plates, plain bearings, etc.) to ensure a tight fit. The scrapers are made from steels U10 and U12A, their cutting ends are hardened without tempering to a hardness of HRC 64...66.

Lapping and finishing are operations of surface treatment with especially fine-grained abrasive materials using laps.

These operations achieve not only the required shape, but also the highest accuracy (5...6th quality), as well as the lowest surface roughness (up to 0.05 microns).

Fitting and assembly work - ϶ᴛᴏ installation and dismantling work performed during the assembly and repair of machines. The various connections of parts made during machine assembly are divided into two basic types: movable and fixed. When performing plumbing and assembly work, a variety of tools and devices are used: wrenches (simple, socket, sliding, etc.), screwdrivers, drifts, pullers, devices for pressing and pressing.

home » Investments » Name the main locksmith operations. Preparatory locksmith operations. Basic plumbing operations and their purpose