The body is the main element of the car, ensuring its proper operation. This component has a complex design, and is periodically subjected to high loads. As a result, problems arise that require intervention. Body repair allows you to repair damage and restore the working condition of the car.
The reasons for the repair are two factors:
- technical;
- human.
The most common manifestation of the first factor is wear and tear. Most of the damage to the body receives as a result of a natural process. This component has an operational period, after which the strength indicators decrease and it becomes vulnerable. The most common cause of wear is corrosion.
Sometimes the cause of problems with the body is non-compliance with the rules for storing a car, or improper use. These actions are related to the human factor. Also included in this category are:
- design flaws made by the manufacturer;
- failures of defects that occur during the assembly of the machine;
- damage due to low-quality repairs.
The human factor includes road accidents. More than 50% of accidents are accompanied by damage to the body of the car.
General body faults:
- operational;
- constructive;
- technological.
Body damage includes violations of the original condition of the element, from minor scratches to large dents or creases.
The organization of the technological process of work on the restoration of the car begins with diagnostics.
Diagnostics determines the presence of all faults, their features and nature. This makes it easier to choose a method of body repair. Diagnostics is performed in three stages:
- The paintwork of the machine is inspected for defects.
- An assessment of the geometry of the body is given - in the presence of irregularities, inspection without special equipment is sufficient.
- A quality assessment is carried out to determine the condition of the welds and fasteners. This task requires attention and experience, since the main load is distributed to these elements.
After the faults are identified, a repair plan is drawn up.
What is body repair
Body repair is a complex of technological actions aimed at restoring the body. The basis of this process involves the elimination of damage of any nature.
There are two types of body repair:
- full - used when eliminating damage of a large size. Most often it is used when restoring a car after an accident;
- local - used when scratches, chips and other minor damage are detected.
The technology of car body repair depends on the level of faults. At a high level using full recovery, special equipment is required.
External repair
Can be done at home. Repair of a local type does not require labor-intensive actions, and is used when eliminating minor damage. Body repairs include:
- scratches and chips;
- small dents;
- early stage of metal rust.
External body repair is carried out using:
- a standard set of tools for body repair;
- polishes;
- paints.
External repair cannot eliminate the overall damage to the elements. Additionally, airbrush tools and fiberglass processing may be required.
Overhaul
Restoration of the body in a capital way in most cases cannot be done independently. Its implementation requires professional equipment and special skills. This type of restoration work involves the dismantling of a car. Its purpose is to detect all defects and minor damage. When performing restoration, even minor elements are removed.
To detect hidden defects, the contact welding zones are drilled out.
Welding work is carried out upon detection of:
- parts corrosion;
- cracks in the body structure;
- deep deformation of parts.
Overhaul is not complete without replacing damaged structural elements.
Align geometry
The main tool used to restore the car body is a slipway. This tool is designed with high strength, sufficient for power work. The main action in alignment is hauling. It involves the use of a system of fasteners that act on the points of the structure, under pressure on which the body part takes on its original shape. This task involves a high level of complexity, which is not easy to cope with in the absence of experience.
With the help of a slipway installation, the measurements necessary for accurate repair work are provided. Alignment of geometry is carried out in stages:
- Fix the vehicle on the slipway platform.
- After calculating the points on the machines, a snap is attached to them.
- Start the stacker.
After starting, the slipway and equipment automatically pull out damage in the desired shape. The equipment involves the use of a computer program that calculates the required level of effort and the measurement of the rack.
The advantage of the stack installation is that it does not violate the quality of the metal in the areas of faults when they are eliminated.
Dent removal
Do-it-yourself body repair of car dents is carried out in three ways:
- With glue. Straightening or editing is performed using the Pops-a-Dent set. It includes a thermal gun, silicone glue, special rods. After applying the glue and fastening the rods, it is necessary to wait for solidification. Then carefully pull out the dents along with the rods.
- Using a vacuum. The main special tool is a vacuum suction cup. It is attached to the surface of the dent, creating a vacuum. After that, the dent can be pulled out without risk of damaging the surface of the coating. Vacuum suction cups are a paintless way to remove dents.
- PDR technology. With the help of special levers that are inserted through the technological holes of the car, you can get to large dents and eliminate them by extrusion.
Patching and welding
If the standard local body repair did not help, patches are used. They are used to seal holes in the body of a car. The patch also allows you to repair through rust, if the diameter of the hole does not exceed 8-10 centimeters. Otherwise, the part is completely replaced.
Before fixing the patch, the edges of the hole are processed. The patch itself must have a diameter greater than the size of the damage (welded with an overlap). For its manufacture, thin metal is used. A continuous seam is used for fastening. It is recommended to use semi-automatic welding machines.
Elimination of scratches and chips
Scratches and chips are removed with the help of minor body repairs. It involves the use of painting and polishing. Additionally, a primer can be applied. The surface is sanded, then a protective coating is applied. New technologies provide polishing, after which scuffs will not be visible. Cosmetic type of repair is easily performed at home.
The paint must be the color of the body finish. Otherwise, the surface of the machine will look unpresentable.
Painting and polishing
For painting in accordance with the technology of car repair, you need to use only substances designed to cover the surface of the car. In some cases, several stages of coloring are required. After body repair and painting, the surface is thoroughly washed.
The painted machine is being polished. Grinding is carried out using soft abrasives only after the paint has completely dried.
- cleaning
- washing
- drying or wiping washed body parts
- periodical
In addition, they check and tighten the fastenings of the car body, check the condition of doors, door locks, hinges, power windows, wipers and other equipment, and lubricate hinges and other joints.
Removing dust and dirt
To avoid scratches, do not remove dust and dirt with a dry cleaning cloth. It is better to wash the car before the dirt dries with a low-pressure water jet using a soft sponge and car shampoo. In summer, it is advisable to wash the car in the shade. If this is not possible, then the washed surfaces should be wiped dry immediately, as spots form on the painted surface when water drops dry in the sun. In winter, after washing the car in a warm room, before leaving, wipe the body, door and hood seals dry, and blow the locks with compressed air to protect them from freezing.
When washing the car, make sure that water does not get on the electrical components in the engine compartment, especially on the ignition coil and distributor.
To maintain the gloss of painted surfaces (primarily for vehicles stored outdoors), car polishes should be used regularly. They close microcracks and pores that have appeared in the paintwork, which prevents corrosion under the paint layer. Polishing can be done with VAZ-1 or VAZ-2 paste, and then with VAZ-3 or similar, manually or with an electric drill.
To keep the surface of the body shiny, you should not leave the car for a long time in the sun, allow acids, soda solutions, brake fluid and gasoline to get on the surface of the body, and use soda and alkaline solutions for washing. Plastic parts should be cleaned with a damp cloth or a special auto cleaner. To prevent the plastic parts from losing their shine, do not use petrol or thinners.
Glasses are cleaned with a soft linen cloth or suede. Very dirty glasses must first be washed with water with the addition of NIISS-4 liquid or glass auto-cleaner. To remove ice from windows and defrost door locks, it is recommended to use an auto defroster in an aerosol package; brake fluid can be injected into the locks.
Dust from the upholstery of cushions and seat backs should be removed with a vacuum cleaner. To eliminate greasy stains on the upholstery, use the “Auto Upholstery Cleaner”.
In winter, glass washer tanks should be filled with an aqueous solution of a special low-freezing liquid NIISS-4 or other similar compounds in accordance with the recommendations for their use.
Eliminate minor body scratches
A small scratch that has damaged only the body color is rubbed with a degreasing liquid to remove the peeling paint and clean the adjacent areas from the protective polish, then rinse it with clean water. Paint over the scratch using a thin brush. Thin layers of paint are applied until the thickness of the color of the damaged area is equal to the surrounding layer. The paint is dried until it is completely dry for several days, then the area of \u200b\u200bthe scratch is polished and a wax coating is applied to it.
If the scratch has damaged the metal of the body, causing rust, another repair method is used. Remove rust from the bottom of the scratch with hard metal, then apply a primer to prevent future rust. Fill the scratch with a special filler based on cellulose. Before the filler in the scratch hardens, lightly run a cotton swab moistened with the cellulose composition over the surface of the filler so that its level is just below the surrounding paint layer. After complete curing of the filler, painting is carried out according to the technology described above.
Car glass care and checking their light transmission
Periodically it is necessary to check the light transmission of the car windows. The essence of the light transmission test method is to determine the normal light transmission of safety glass from the intensity of the light flux transmitted by the tested glass. Normal light transmission is the ratio of the light flux Фt transmitted by glass to the total incident light flux Фi.
The schematic diagram of the device for determining the coefficient of light transmission is shown in the first figure, and its general - in the second.
Rice. Scheme of the ISS-1 device (Russia):
1 - light source; 2 – optical system; 3 - diaphragm; 4 - tested glass; 5 – radiation receiver; 6 - measuring device
Rice. General view of the ISS-1 device:
1 - light source; 2 - measuring device; 3 - radiation receiver
The device consists of a measuring unit with a liquid-crystal or pointer indicator, a light source, a radiation receiver (photodetector). The device can be powered from the car's on-board network or from a battery. The housings of the light source and photodetector are equipped with powerful ring magnets, which allow you to fix the light source and photodetector opposite each other when measuring light transmission.
When checking, the radiation source is installed on one side, and the receiver on the other side. In the case of using the ISS-1 device, calibration by glass thickness is not required.
According to the Rules of the Road in the Republic of Belarus, it is prohibited to participate in road traffic of vehicles, the degree of light transmission of which is less than 75% for the front side windows and less than 70% for the rest of the windows, unless otherwise determined by the President of the Republic of Belarus.
The vehicle must be equipped with the windshield wipers and windscreen washers provided for by the design.
The frequency of movement of the brushes on wet glass in the mode of maximum speed of the windshield wipers must be at least 35 double strokes per minute, while the sweep angle of the brushes must not be less than that provided for by the design of the vehicle.
Wiper blades must wipe the area being cleaned in no more than 10 double strokes for buses and no more than 5 double strokes for other vehicles so that the total width of the unwiped strips at the edges of the wiped area does not exceed 10% of the length of the blade. At the same time, the windshield washers must ensure the supply of liquid to the glass cleaning zones in an amount sufficient to wet the glass.
Checking the technical condition of the elements providing visibility is carried out in the specified order.
- Inspect the glass of the vehicle for compliance with the design, the presence of appropriate markings, the absence of unacceptable damage and the application of tinting. If an attached or applied transparent strip is used on windshields, measure its width or assess its compliance with the specified requirements.
- Measure the light transmittance of the windscreens and front side windows of the vehicle. For a windshield, the measurement should be made at three points in the wiper zone at a level approximately corresponding to the level of the driver's eyes while driving, while driving the vehicle. For front side windows, the measurement should be taken at three points located on a diagonal line connecting the lower front (taking into account the direction of movement of a motor vehicle) corner of the window and the upper rear. In this case, these points should be approximately equidistant from each other and the visible edges of the glass.
For other glasses, the measurement is carried out at one point located on a horizontal line passing in the middle of the glass.
At each point, at least two measurements must be made.
Determine the light transmission coefficient of the windshields and front side windows using the formula:
where хi is the result of measuring the light transmission at the i-th point on the glass, %.
The result of measurement at one point is taken as the value of the light transmission coefficient of the remaining glasses. It should be rounded up to a whole number. Add 3% to the values obtained. The result should not exceed the normative value established for the specific type of glass.
Abstract on the topic:
"Body and Cabin Repair"
Is done by a student
3 courses 33-AK group
Speciality:
Maintenance and car repair. and tr-a
1. Defects of bodies and cabins…………………………………………3
2. Technological process of repair of bodies and cabins……………. 4
3. Repair of equipment and mechanisms of the body and cabins………….. 6
4. Repair of non-metallic body parts……………………. 6
5. Assembly and control of bodies and cabs………………………………….. 7
REPAIR OF BODIES AND CABINS.
Defects of bodies and cabins.
Typical defects in body parts, cabs and plumage (Fig. 1.) Are corrosion damage, mechanical damage (dents, breaks, tears, bulges, etc.), violation of geometric dimensions, cracks, destruction of welded joints, etc.
Corrosion damage is the main type of wear of a metal body and cabins. Here, an electrochemical type of corrosion takes place, in which the metal interacts with an electrolyte solution adsorbed from air. Corrosion develops especially strongly in places that are difficult to access for cleaning, where moisture periodically getting into them persists for a long time, and, due to an increase in ambient temperature, the oxidation reaction is intensified. Corrosion damage also occurs as a result of contact of steel parts with parts made of duralumin, plastic, wet wood and other materials.
Cracks occur as a result of metal fatigue, a violation of metal processing technology, the use of poor shaft quality, defects in the assembly of units and parts, insufficient structural strength of the unit, as well as in places subject to vibration.
Destruction of welded joints occurs as a result of poor-quality welding, exposure to corrosion, vibration and stress during normal operation of the vehicle or as a result of accidental damage.
Mechanical damage (dents, distortions, breaks, etc.) are the result of overstressing of the metal as a result of impacts and bends, as well as due to loose connection of parts.
A
Fig.1. Characteristic damage :
A -all-metal body car :
1
- front and rear windshield openings;
2 - doorways;
3 - racks under the roof;
4 - front and rear spars;
5 - left and right thresholds of the base;
6 - bottom;
7-left and right rear mudguards
8 - violation of geometric dimensions;
9 - top and bottom, respectively, of the left and right rear mudguards;
10 - left and right front mudguards;
b - truck cab :
1 - destruction of welding seams; 2 - breaks; 3 - dents and bulges; 4 - deflection and distortion of the racks; 5 - holes; 6 - corrosion; 7-cracks
Technological process of repair of bodies and cabins.
The technological process of body and cab assembly repair includes dismantling, complete or partial removal of old paint, troubleshooting, repair of components or their replacement, assembly, painting and quality control.
Dismantling of bodies and cabins is carried out in two stages. This is the dismantling of all parts and assembly units installed on the inside and outside of the bodies and cabs, followed by disassembly of the body for repair after removing the old paintwork and identifying all its defects. Since in most cases all-metal bodies of bodies and cabs are one-piece (connected by welding), the body is not completely disassembled into panels and parts. It is carried out only to such an extent that it is possible to make a defect and, if necessary, replace or repair the elements of the body that form the frame.
Depending on the economic feasibility of repairing bodies and cabs, various methods are used to eliminate defects present on their surfaces.
The greatest labor intensity and cost of repairing bodies and cabs is the work to eliminate defects on their all-metal welded bodies. Repair of a body hull with various defects includes straightening panels, removing damaged sections of hulls, eliminating cracks and tears, fixing DRD in place of removed panels, forging and cleaning old seams, final straightening and leveling surfaces.
Irregularities in the panels are leveled by spraying powder plastics or epoxy compositions. To level dents in hard-to-reach places, a Tool of various shapes is used (Fig. 2). The bent end of the mandrel is inserted into the hole of the inner panel and the wrinkled surface is leveled by hammer blows on its handle. To eliminate shallow shallow dents, a hole with a diameter of 6 mm is drilled in it, into which a rod with a curved end is inserted and the concave part of the panel is pulled out to its normal position. The hole is then sealed with solder or epoxy.
 |
Rice. 2. Dent Removal Tool Set:
1...6 - hammers; 7 and 8 - mallets; 9 - mandrels (spoons)
Editing panels with emergency damage provides for work on stretching, leveling, squeezing and knocking out deformed parts of the body or cab to give them their original shape and size. When performing these operations, it is necessary that the tensile force be applied at the same angle at which the force that caused the damage was applied. In order for the tension to be controlled, an opposing force must be applied opposite the point of application of the tensile force. When performing these works, it is necessary to control the stretching process, as well as possible accompanying deformations caused by the tensile force.
Editing emergency bodies and cabs is performed on stands (Fig. 3) using a set of devices (Fig. 4). Tensile and compression forces are created by working cylinders 1, 3 (Fig. 3), in which the liquid comes from the pump. For editing the body 4 set on stands 6, which are fixed on the base frame 2. The power transverse pipes rest on the supports, which are fixed with the jaws of the clamps to the stiffening ribs of the body sills. The fastening of the latter to the frame is performed by braces 5. Deep dents are eliminated by preliminary editing (Fig. 4, b) bends (Fig. 4, V) and distortions (Fig. 4, G). Since cracks or gaps may form during the straightening process, which must be eliminated in the future, straightening is carried out before welding.
Removal of damaged sections of bodies and cabs perform gas cutting, electrified milling tool or pneumatic cutter. The advantages of a pneumatic cutter are high labor productivity (0.08 ... 0.1 m/s) compared to gas cutting (0.02 m/s) and better edge quality at the cutting points. Defective areas are marked with templates and chalk, and then removed. When removing defective sections of the body or cab, it is necessary to protect the body from geometry distortion due to the weakening of its rigidity and under the action of its own weight.
Cracks and breaks in the body of bodies and cabs are eliminated by semi-automatic arc welding in carbon dioxide or gas welding. When repairing, preference is given to welding in a carbon dioxide environment, since the productivity of this process and the quality of the weld are higher. Welding is carried out by semi-automatic devices powered by direct current sources of reverse polarity with a power of 40 A and a voltage of 30 V, using electrode wire Sv-08GS or Sv-08G2S with a diameter of 0.7 mm. To limit the propagation of a crack during welding, its ends must be drilled with a drill with a diameter of 8 mm.
Gas welding eliminates cracks and gaps in panels made of sheet steel 0.5 ... 2.5 mm thick, with VSM-53 or GS-53 burners with tips No. 1 (for sheets with a thickness of B.5 ... mm) and No. 2 (for sheets 1.0 ... 2.5 mm), using for this wire Sv-08 or Sv-15 with a diameter of (0.5L + 1) mm, where h is the thickness of the metal being welded. So that the part does not lose its willow shape when heated, first welding is carried out at separate points with an interval of 10 mm, and then, as necessary, individual sections are welded with a continuous seam from the ends of the crack to the middle.
Fig.3. Stand for editing the car body:
1,3 - working cylinders;
2 - frame;
4 - body;
5 - bracing device;
6 - stand
Production of an additional repair part they start with straightening the steel sheet, cutting it and cutting blanks according to the markup. After it, the part is bent or molded on special equipment, the finished parts are cut, drilled, straightened and cleaned. The material for the manufacture of the repair part is thin-sheet cold-rolled mild steel with a thickness of 0.7 ... 1.5 mm.
Rice. 4. Devices for editing deformed body area:
A- a set of devices for eliminating distortions and kinks;
b, V And G- use of tools for editing;
1 - mandrel for drawing concave parts;
2 And 3 - self-locking hydraulic clamps;
4 - mandrel with teeth for gripping the straightened panel;
5 - pump;
6 - double grip;
7 – tension cylinder with pulling device;
8 – tension cylinder with grips;
9 - correct device
Forging and cleaning of welded seams necessary to strengthen the welding site and give it the required profile. It is performed with a pneumatic hammer using a set of supports and strikers. After forging, the welding spots are cleaned with an abrasive wheel installed in pneumatic or electric portable machines.
Final editing and straightening body panels and cabs is designed to ensure assembly accuracy and remove small dents and bulges remaining on surfaces. Straightening is performed by a pneumatic straightening device or manually. Repair weld damage.
Repair of equipment and mechanisms of the body and cabins.
Fittings of bodies and cabs include power windows, locks, door stops, door hinges, hoods, etc.
Power windows may have the following defects: cracks and broken parts; skew and deformation of clips, frames and guides; loosening of rivet connections; damage to rubber seals; parts corrosion. Power windows and glass fastening mechanisms are subject to disassembly, washing, flaw detection, repair and assembly. In case of fault detection, the following are rejected: parts with broken parts; springs that have lost their elasticity; clips with worn glass, not amenable to compression; rivets that cannot be tightened; damaged rubber seals and other parts with wear on surfaces that affect the normal operation of the mechanism. Cracks in the parts are eliminated by welding, followed by cleaning of the welds, the curvature of the parts is straightened in a cold state.
Door locks may have the following defects: cracks and breaks, damage to the threaded holes, corrosion on the surfaces of the part, weakening of the springs and rivets fastening the parts, wear on the surfaces of the parts. Repair of locks consists in their disassembly, washing in kerosene, defect detection, restoration of damaged parts, assembly and adjustment. Parts that have deep traces of corrosion, worn surfaces and breaks, springs that have lost their elasticity are subject to rejection. Cracks in the lock body are welded. Broken off screws in threaded holes are removed. The damaged thread in the hole is welded, the welding spot is cleaned flush with the base metal, the hole is drilled and the thread is cut in accordance with the size on the working drawing. Minor deposits of corrosion on the surfaces of parts are cleaned with a scraper or sanding paper and washed off with kerosene.
door hinges may have defects: cracks and breaks, wear of holes and axles, curvature. Worn door hinge pins are replaced with new ones. Cracks and hole wear are eliminated by welding followed by machining. Worn holes for the hinge axis are expanded to the repair size, and the curvature of the hinge is eliminated by editing.
Repair of non-metallic body parts.
In the manufacture of automobiles, non-metallic materials are widely used: wood, plastics, synthetic leather, glass, rubber, etc. Most of the parts made from these materials cannot be restored during repair, but are replaced with new ones made at a repair company or manufacturer.
Wooden parts of the platform and body are made from softwood lumber (pine, spruce) with a moisture content of not more than 18%. The main defects are breakages, cracks, spalls, hole wear. Parts that have destroyed spikes or sockets for spikes are replaced with new ones. The wooden parts of the body platform are repaired by increasing them in length or by replacing unusable boards. Boards or bars are cut into blanks of certain sizes, planed from all sides, ends are cut, lugs, grooves are cut, holes are drilled, etc. For gluing wooden parts, phenol-formaldehyde adhesives such as VIAMB-3 and casein are used. The sequence of work: the surface intended for gluing is treated so that the parts fit snugly against each other and ensure that the adhesive film is uniform in thickness; the glue is applied with a brush on the surfaces to be glued (the exposure time in air for the VIAMB-3 glue is 4 minutes); assembly exposure of parts under pressure of 0.2 ... 0.3 MPa at a temperature of 16 ... 20 ° C for 5 hours; holes from fallen knots, bolts, screws are sealed with wooden cylindrical inserts from the same type of wood as the part being repaired on the glue, and the cracks are filled with mastics, wood putty, resin glue, or by placing wooden inserts on the glue, tightly fitted in place divided crack.
sheathing textile materials or leather substitutes during the repair of cars are replaced with a new one, since during operation the material ages, loses elasticity and other physical and mechanical properties.
Cabin and body glass may have scratches, turbidity, yellowness, iridescence, brush wear and other defects. Windshields and side windows with yellowness, iridescence and wear from brushes are rejected. Risks and scratches are eliminated by grinding, followed by polishing. The glass to be restored is cleaned of dirt, dust and grease. The areas of glass marked with chalk are polished with a felt upholstery of the circle, on which a layer of paste is applied, which is an aqueous solution of pumice, with a circle rotation frequency of 300 ... glass with an aqueous solution of crocus or polyrite with a circle rotation frequency of 700 ... 800 min - "until the required transparency is obtained. After processing, the glass is degreased.
Assembly and control of bodies and cabins.
WITHassembly of bodies and cabins when repairing cars, they perform in the following sequence:
before painting, all parts and assembly units to be painted together with the body (doors, hood, plumage, trunk lid, etc.) are installed on them, maintaining the required gaps between mating parts;
after applying paint coatings, the installation of the ceiling, sidewalls and interior trim panels of doors, windows, seats, noise and heat insulating gaskets, door seals, electrical equipment, instrument panel, parts of the ventilation and interior heating system, etc.
Subject to control: geometric deviations in the dimensions of the arrangement of groups of holes, interconnected functionally, using control and measuring equipment for this; openings of bodies and cabs and interfaces are controlled by templates according to the shape of the mating part; tightness and dust tightness of the body and cab. The tightness of the assembled body is checked in sprinkling installations at a water pressure of 2 kgf/cm2 for 6 minutes, while the penetration of water and the formation of condensate in lighting and signaling devices are recorded. The tightness of the door to its opening is determined by rubbing the seals with chalk. When the door is slammed, a uniform imprint of chalk should remain on the body or cab. Adjustment of the tightness of the door seals is achieved by moving the latch of the lock.
Dear Clients!!!
Body repair prices are valid under the condition that the threaded fasteners (nuts, bolts, screws, etc.) are in a normal condition, normally unscrewing without additional heating, and using special. liquids and funds. For cars older than 7 years, a coefficient of 1.25 is introduced.
We have indicated prices for the main types of car body repair. If you did not find the work you need in our price list, this does not mean that we do not do it. We carry out a full range of body repair work
Evaluation of body work for each car is a purely individual matter. Please call and describe the breakdown or your question to our specialist in as much detail as possible. This will help us give more detailed advice and understand the essence of the problem. Call -
|
Name of repair work |
price, rub. |
|
1. Painting work. |
|
| Painting the front fender of a car | from 5 000 |
| Car rear fender painting | from 5 000 |
| Car front door painting | from 5 000 |
| car rear door painting | from 5 000 |
| car hood painting | from 7 000 |
| Car rear bumper painting | from 5 000 |
| Car front bumper painting | from 5 000 |
| Car trunk lid painting | from 5 000 |
| Car roof painting | from 5 000 |
| Painting the front panel of the car | from 5 000 |
| Painting the back of the car | from 5 000 |
| Painting the rear panel of the car | from 5 000 |
| Car trunk floor panel painting | from 4 000 |
| Car exterior mirror painting (with installation) | from 2 000 |
| Full car body painting | from 55 000 |
Protective body polish |
|
| Protective body polish | from 6 000 |
|
2. Stacking works. |
|
| putting the car on the slipway | from 2 000 |
| elimination of a simple skew of the car body | from 5 000 |
| elimination of skew of the body of a car of medium complexity | from 10 000 |
| elimination of complex skew of the body of foreign cars | from 12 000 |
|
3. Reinforcing work. |
|
| removal of the front bumper of the car assembly | from 1 000 |
| installation of the front bumper of the car assembly | from 1 000 |
| Removing the car's rear bumper assembly | from 1 000 |
| car rear bumper installation assembly | from 1 000 |
| rear bumper disassembly | from 500 |
| car rear bumper - assemble | from 500 |
| front bumper disassembly | from 1 000 |
| car front bumper - assemble | from 1 000 |
| front car door - disassemble, assemble for painting | from 2 000 |
| rear car door - disassemble, assemble for painting | from 2 000 |
| front door of foreign cars, rear door - replacement with reinforcement bulkhead | from 2 500 |
| car door front, rear assembly - replacement with adjustment to the opening | from 2 500 |
| side mirror of foreign cars without electric drive - replacement | from 500 |
| side mirror of foreign cars with electric drive - replacement | from 500 |
| headlight replacement | from 500 |
| rear light replacement | from 500 |
|
4. Replacement of body parts. |
|
| Car hood replacement | from 2 000 |
| Car trunk lid replacement | from 2 000 |
| Replacing the front fender removable | from 2 000 |
| Replacing the roof of a car without a sunroof assembly | from 10 000 |
| Car roof replacement with sunroof assembly | from 15 000 |
| Replacing the front side member with a mudguard | from 7 500 |
| Replacement car back panel assembly | from 7 500 |
| Replacing the front panel of the car assembly | from 4 000 |
| Replacement of a threshold of a sidewall of a car assy | from 6 000 |
| Replacing the middle rack with part of the threshold assembly | from 10 000 |
|
5. Repair of body parts. |
|
| Repair No. 1 sidewall of the car - sedan | 10 000 |
| Repair No. 2 of the sidewall of the car - sedan | 13 000 |
| Repair No. 3 of the sidewall of the car - sedan | 16 000 |
| Repair No. 4 of the sidewall of the car - sedan | negotiable |
| Repair of the sidewall of the car - station wagon No. 1 | 12 000 |
| Repair of the sidewall of the car - station wagon No. 2 | 14 000 |
| Repair of the sidewall of the car - station wagon No. 3 | 18 000 |
| Repair of the sidewall of the car - station wagon No. 4 | negotiable |
| front mudguard repair No. 1 | 2 000 |
| repair of the mudguard of the front car No. 2 | 3 000 |
| front mudguard repair No. 3 | 4 500 |
| front mudguard repair No. 4 | negotiable |
| repair of the front door of the car No. 1 | 1 500 |
| repair of the rear door of the car No. 1 | 1 500 |
| repair of the back door of the car No. 2 | 3 000 |
| repair of the front door of the car No. 2 | 3 000 |
| repair of the front door of the car No. 3 | 4 500 |
| repair of the rear door of the car No. 3 | 4 500 |
| repair of the front door of the car No. 4 | negotiable |
| repair of the rear door of the car No. 4 | negotiable |
| car hood repair №1 | 1 500 |
| car hood repair №2 | 3 000 |
| car hood repair №3 | 5 000 |
| car hood repair №4 | negotiable |
| repair of the front fender of the car No. 1 | 1 000 |
| repair of the front fender of the car No. 2 | 2 000 |
| repair of the front fender of the car No. 3 | 3 500 |
| repair of the front fender of the car No. 4 | negotiable |
| car roof panel repair no.1 | 1 500 |
| car roof panel repair No. 2 | 3 000 |
| car roof panel repair no. 3 | 6 000 |
| car roof panel repair No. 4 | negotiable |
| repair No. 1 car trunk lid, 5th door | 1 500 |
| repair No. 2 car trunk lid, 5th door | 3 000 |
| repair No. 3 car trunk lid, 5th door | 5 000 |
| repair No. 4 car trunk lid, 5th door | negotiable |
| repair of the rear panel of the car No. 1 | 2 500 |
| repair of the rear panel of the car No. 2 | 4 000 |
| repair of the rear panel of the car No. 3 | 6 500 |
| repair of the rear panel of the car No. 4 | negotiable |
| repair of the threshold of the sidewall of foreign cars | from 2 000 |
|
6. Additional body work |
|
| Restoration of clouded plastic headlights of foreign cars | from 800 |
| Abrasive polishing of car body | from 8 000 |
| Protective polishing of the car body | 5 000 — 10 000 |
PAGE \* MERGEFORMAT 32
I . Introduction …………………………………………………………… 1
II . Main part……………………………………………………… 3
2.1. Major body damage……………………………………. 3
2.2. Preparing the body for repair …………………………………….. 3
2.2.1.Acceptance of the body for repair……………………………………………… 3
2.2.2. Body disassembly……………………………………………………… 7
2.2.3. Removal of paint and varnish coatings and cleaning of bodies from products
Corrosion……………………………………………………………… 9
2.2.4.Defectoscopy of the body………………………………………………... 10
2.3. Accidental damage to the body……………………………………... 11
2.4. Damage resulting from the operation of bodies……….. 16
2.5.1. Body repair methods……………………………………………… 18
2.5.2. In-line method of body repair and assembly……………………… 18
2.6. Body repair methods……………………………………………… 21
2.6.1. Repair by replacing damaged parts……………………………. 21
2.6.2. Correction of deformed panels and openings by mechanical
Impact…………………………………………………………. 22
2.6.3. Editing using heat………………………………………. 27
2.7. Restoration of non-metallic parts…………………………. 28
2.8. Repair of the main mechanisms and equipment of the body…………….. 29
2.9. Body assembly…………………………………………………………. 31
III . Safety and labor protection ………..…………………….. 33
3.1. Basic provisions on labor safety……………………….. 33
3.2. Requirements for technological processes………………………….. 34
3.3. Requirements for working premises………………………………….. 35
IV . Conclusion……………………………………………………………... 36
V . List of used literature…………………………………….. 37
I. Introduction.
One of the reserves for increasing the country's car park is the organization of car repairs at the proper level. The need and expediency of repair are primarily due to the fact that during long-term operation, cars reach a state where the costs of funds and labor associated with maintaining them in working condition exceed the income from their further operation. Such a technical condition of cars is considered to be limiting and is due to the uneven strength of their parts and assemblies. It is known that it is practically impossible to create a machine with equal strength, all parts of which would wear out evenly and have the same service life. Consequently, repairing a car, even just by replacing some parts that have a small resource, is always expedient and justified from an economic point of view.
The main source of economic efficiency of car repair is the use of the residual resource of their parts. About seventy percent of car parts that have passed the service life before repair have a residual resource and can be reused either without repair or after a small repair impact.
One of the main units of the car is the body. Bodies of cars and buses are also the most difficult units to manufacture. The labor intensity of manufacturing a body, for example, for cars, is 60% of the entire labor intensity of manufacturing a car. The body also includes plumage: radiator lining, hood, fenders, trunk lid. Rigidity and strength of the body increase the life of the car. The failure of the body practically means the failure of the car.
For the rolling stock of road transport in the public sector, the task of maintaining it in good condition, as well as repairing components and assemblies, is successfully implemented by a clearly regulated system of control and periodic technical impacts at road transport enterprises (ATP) and car repair plants (ARZ). The current policy of concentrating car repairs in production associations of the automotive industry will make it possible to consolidate and specialize enterprises. At large specialized car repair enterprises, conditions are being created for the widespread use of the most advanced technological processes and modern high-performance equipment. This general direction in the development of auto repair production will lead to a sharp increase in the quality of car repair and the most complete realization of its economic advantages.
Currently, the fleet of cars owned by citizens has grown dramatically. Maintaining this fleet in a working condition is possible mainly on the basis of a widely developed car service system. A whole network of service stations (SRT) has been built and put into operation throughout the country, where maintenance and repair of personal cars is carried out.
II . Main part.
2.1 Major body damage
During operation, body elements and assemblies (assembly units) experience dynamic stress loads from bending in the vertical plane and twisting, loads from their own weight, the weight of cargo and passengers. The body and its components are also affected by significant stresses resulting from its vibrations when moving over bumps, shocks and impacts during a collision, as well as due to errors in balancing rotating components, displacement of the center of gravity in the longitudinal and transverse directions. These stresses cause the accumulation of fatigue and lead to the destruction of body elements.
In the bodies of cars coming in for repair, there are: damage resulting from an increase in changes in the state of the body; these include natural wear and tear that occurs during the normal technical operation of the car, due to the constant impact on the body of factors such as corrosion, friction, elastic and plastic deformation, etc.; damage, the appearance of which is associated with human actions, design flaws, violation of body maintenance standards and technical operation rules, and also caused by transport accidents (accidents).
2.2 Preparation of bodies for repair
2.2.1 Acceptance of bodies for repair
Bodies received for repair must meet the requirements of the technical conditions for the delivery and repair of cars with the appropriate body structure. The technical conditions provide for permissible damage to the body and its certain completeness. Incomplete bodies or bodies requiring repair, the volume of which exceeds the maximum allowable technical conditions, as a rule, are not accepted for repair. Usually they check the presence of doors, interior seat upholstery, glass with clips and frames, wind, pivot and rear windows, ceiling lamps, internal and external handles, decorative overlays, mechanisms: locking, raising and lowering windows, heating equipment, ventilation, wipers. External washing of the body is carried out in a room specially equipped for this purpose, usually before disassembling the car into units. After external washing, the body is subjected to preliminary control, during which a thorough external inspection of the components and parts that are subject to mandatory removal from the body during its overhaul (internal upholstery of the body, glass, fittings, decorative overlays, etc.) is carried out to determine their condition and the feasibility of repair . The main purpose of preliminary control is not to clutter up production facilities with useless (scrap) parts. Then they remove from the body all components and parts that cover the body from the inside and outside, as well as all units of the running gear of cars from the body of the supporting structure. For a thorough (final) cleaning of the bottom of the body from dirt, it is washed again.
The components and parts removed from the body, depending on their condition, are sent to the appropriate compartments for storage, repair or to a scrap warehouse, and the running gear units are sent to the assembly and repair department. The old paintwork is removed from the body. The body, disassembled in this way and cleaned of the old coating, undergoes a detailed control, in which the nature of the damage is revealed, the repair procedure is outlined, and the complexity of the repair work is determined. The results of the preliminary and final control are entered into the inspection sheet, which is the main document that determines the condition of the body before repair. In the control and sorting list, three groups of parts are noted: good, requiring repair, requiring replacement (unusable). A copy of the statement goes to the master of the corresponding repair site, and the original goes to the accounting department of the repair company to determine the cost of body repairs.
Then the body goes to the repair site, where the damage is repaired.
Schemes of technological processes for repairing car bodies, buses and truck cabs differ from each other in the presence of various equipment and mechanisms on them, as well as damage characteristic of each body structure and ways to eliminate them.
Figure 5 General scheme of the technological process of body repair
2.2.2 Dismantling of bodies
Dismantling of bodies can be partial or complete, depending on the required repair and the condition of the body. Partial dismantling is carried out when the body as a whole is in good condition and only individual parts damaged due to wear, loose fastenings or an accident need to be repaired. Complete disassembly is carried out, as a rule, during the overhaul of the car and when most of the body components need to be repaired.
Body parts can only be properly disassembled if a certain technological sequence is strictly observed.protection to prevent breakage and damage to parts. Therefore, the disassembly order is established by the technological process, which is developed for each type of body.
When disassembling bodies and plumage, laborious work is unscrewing rusted bolts, nuts and screws, removing rivets, separating spot-welded panels. To remove fasteners that cannot be unscrewed, one of the following methods can be used: heat the nut with a gas flame; this method is very effective and acts quickly; after heating, the nut is usually easily unscrewed; bite off a bolt with a nut with wire cutters or cut with a hacksaw; cut off the nut with a chisel; drill a hole in the head of the bolt with a diameter equal to the diameter of the bolt shaft; after drilling, the head falls off, and the shaft of the bolt with the nut is knocked out with a beard. This method has been successfully used for turning pan head bolts connecting wooden parts; cut off the head of the bolt or screw with a gas flame and knock the rod with the nut out of the socket.
Currently, to facilitate the loosening of rusted bolts and nuts, special chemical compounds are widely used, which, when applied to bolted joints, partially remove corrosion products on the thread, and due to their good penetrating ability, lubricate the thread between the bolt and nut and thereby facilitate the dismantling of the threaded joint. Usually such compositions are produced in aerosol packaging and applied by spraying.
In screws that cannot be unscrewed due to jamming or wear of the head slot, the head should be drilled, and then, after removing the part, unscrew or pull the screw out of the wood. Rusted door hinge screws are heated with a gas flame, after which they are easy to unscrew. Jointing of riveted joints is carried out so as not to damage the dismantled panels if they are not to be replaced. Parts reinforced with spot welding are cut off with a sharp thin chisel or the weld points are drilled through the top sheet of the panel from the non-front side of the body. Particular care is required when disassembling fragile and easily damaged parts. Parts to be scrapped may be removed in any way that accelerates disassembly, up to damage, if they cannot be removed, provided that the associated good parts are not damaged.
With a complete dismantling of bodies, the scope of work and the procedure for their implementation largely depend on the structure of the body and on the amount and nature of damage. The sequence of body disassembly is reduced mainly to the removal of seat cushions and backs, interior equipment, handles, handrails, holders, chrome fittings and decorative trims, trim frames, armrests, ceiling lamps, internal partitions, interior upholstery, various mechanisms, body glass, electrical wiring, pipes heater and other parts and assemblies installed inside the body. For ease of disassembly, the body is mounted on a special stand.
2.2.3 Removal of paint and varnish coatings and cleaning of bodies from corrosion products
Old paintwork can be removed mechanically using sandblasting (shot blasting) machines or mechanized hand tools, chemical treatment with special washes and alkaline solutions.
Shot blasting and cleaning with a mechanized hand tool simultaneously removes rust and scale along with the paintwork. The most common abrasive material for shot blasting of metal surfaces is metal shot produced by the industry with a grain size of 0.2 - 0.3 mm. To clean the body panels and plumage, made of sheet steel with a thickness of 0.8-1 mm, from the old coating and obtain the necessary roughness, the optimal angle of inclination of the shot jet to the treated surface should be 45 °, and the air pressure should be 0.2 - 0.3 MPa. The roughness of the treated surface should not be more than 20 - 30 microns, which ensures the high quality of the newly applied protective coating.
For the implementation of shot blasting, a mobile shot blasting machine with a hand gun is used. This device provides for automatic regeneration of abrasive shot and its supply to the shot blast gun.
Various installations are used to remove corrosion products by manual mechanical means. Of these installations, the most interesting is the needle cutter. The needle cutter was made from straight pieces of high-strength wire with a certain packing density. Such a tool can cut off a layer of rust, scale, metal with a thickness of 0.01-1 mm. From a manual mechanized tool for cleaning the surface and removing paint and varnish coatings, grinders MSh-1, I-144, grinders ShR-2, ShR-6 are also used. This method of cleaning is used for small volumes of work, as it does not provide the required quality and productivity of work.
To remove coatings by chemical means, various washes are used. Washes are applied to the surface by spraying or brushing. After a few hours, the coating swells and is removed mechanically, and then the surface is washed with water.
2.2.4 Defectoscopy of bodies
After removing the old paintwork, the body is subjected to careful control in order to reject unusable parts, select suitable ones, and determine the type and extent of repair work. The quality of the repair largely depends on the method of flaw detection and the thoroughness of its implementation. To detect defects in the body body, as well as to control newly manufactured parts, welds, non-destructive testing methods are used.
The technical condition of the body is usually checked by an external examination of the surface of the parts with the naked eye or with the help of simple multiple magnification magnifiers. This method makes it possible to detect surface cracks, corrosion erosion, deformations, etc. Measurement with special devices, templates makes it possible to detect deviations in the geometric dimensions of parts from the original ones (distortions, deflections, etc.).
However, external examination can only establish large, visible damage to the eye. In some places of the load-bearing elements of the body, hairline cracks appear, which can be detected by special methods. Methods based on the molecular properties of the liquid are called capillary methods (methods of penetrating liquids). The most common are kerosene and luminescent methods. Kerosene, having good wettability and low surface tension, easily penetrates into leaks. The essence of this method is that the area to be examined is moistened with kerosene and wiped dry or dried with a stream of air. Then this place is covered with an aqueous solution of chalk. Due to the absorption of kerosene by chalk, a fatty trace appears on the chalk surface, repeating the geometry of the detected crack. For this method of flaw detection, commercially available penetrating and developing compounds based on dyes and enamels can be used. The paint method can reveal cracks with a width of 0.005 mm and a depth of up to 0.4 mm. For the correct choice of the method and volume of repair of a car body made of thin sheet steel, the depth of corrosion damage should be determined during body flaw detection. For this purpose, gamma thickness gauges are used, based on measuring the intensity of gamma radiation. The device allows you to measure sheets with a thickness of 0 to 16 mm, while the measurement time does not exceed 30 s.
2.3 Accidental damage to bodies
The most severe damage is caused by frontal collisions with the front part of the body at an angle of 40-45 ° or from the side between two vehicles moving towards. In such collisions of the car, the front part of the body is especially severely destroyed, while the acting large loads in the longitudinal, transverse and vertical directions are transferred to all adjacent parts of the frame and especially to its power elements.
In the event of a frontal collision of a car (Figure 1) with the front part of the body in the area of the left front fender, side member and left headlight, the front panel, fenders, hood, mudguards, front spars, wind window frame and roof are deformed. In the figure, this can be seen from the lines indicated by the dotted line. At the same time, invisible deformation is transmitted to the front, center and rear pillars on both sides, the front and rear left doors, the left rear fender and even to the rear trunk panel.
Figure 1 Frontal collision with the front of the body
Directions of load distribution and possiblein case of a blow inflicted on the front part of the body at an angle of 40 - 45° (Figure 2), the front fenders, hood, front panel, mudguard, front spars are damaged.
Figure 2 Collision with the front left side of the body at an angle of 40-45°
In the event of a side impact by the front part of the body (Figure 3), in the area where the front panel mates with the front part of the spar and the left wing, both front wings, the front panel, the spar mudguards, and the hood are deformed. In addition, under the action of tensile forces, the opening of the left front door is broken, and under the influence of compressive forces, the opening of the right door and the sidewall of the left front door are deformed. At the same time, significant power overloads are transmitted to the front and central racks, causing them to deviate from their original position.
Figure 3 Collision from the side with the front part in the area of the junction of the front panel with the langeron and the left wing
In the event of a side impact (Figure 4) by the A-pillar on the left side, the left A-pillar, wind window frame, roof, floor and front floor spars, front panel, hood, fenders, mudguards, front spars are significantly deformed. In this case, the front part of the body is taken away to the left; the threshold and the upper part of the right sidewall perceive tensile loads, and the central and rear pillars perceive compressive loads.
Figure 4 Collision from the side of the left A-pillar
The presence of invisible deformations in the load-bearing elements of the body can be established by taking measurements: by the presence of distortions in the front parts, protrusions of one part relative to another, unacceptable gaps in the interfaces of openings with doors, hood, trunk lid.
From the above examples, it can be seen that as a result of accidents, the deformation propagates along the mating elements of the body, causing a violation of the geometry of its openings and base points of the floor. To eliminate such damage, requiring the replacement of most parts and complex repairs, is possible only with the help of special equipment, using hydraulic and manual straightening methods in repair operations, followed by control of the body geometry.
2.4 Damage resulting from the operation of bodies
In metal bodies, there are also less significant damages that worsen their appearance.
dents appear as a result of permanent deformation upon impact, improper repair, and also due to somehigh-quality assembly of body parts. Dents can be simple, easily repairable, and complex - with sharp bends and folds, can be located in places that are difficult to repair.
Cracks are among the most common damage. They can appear in any part of the body as a result of overstressing of the metal (shocks, bends), as well as due to the fragile connection of components and parts and insufficient structural strength.
Ruptures and holes can be divided into simple ones, which take the form of a normal crack after straightening the metal, and complex ones, requiring patching when repairing a damaged patch.
Breaks in body parts are characterized by the size of the torn off part of the panel or plumage. Large breaks are often eliminated by setting up new inserts of a complex profile, and sometimes a complete replacement of the part is made.
Stretched metal surfaces are distinguished by their location: on the surface of the panel in the form of a bump and in the flanges of parts (stretched sides and edges).
Corrosion in its external manifestation can occur in the form of uniform, when the metal is destroyed evenly over the entire surface, and local, when the metal is destroyed in separate areas; this form of corrosion shows up as dark spots or deep black dots on the metal and is more dangerous because the metal can quickly break down to form through holes.
Violation of welded joints occurs in the nodes of parts that are connected by spot welding, and in continuous welds of the body.
Riveted seam failure is the result of loosening or shearing of rivets, as well as wear of bolt holes and rivets.
Deflections, distortions and twisting usually result from emergency loading. Distortions can be internodal and in the plane of one node or part (distortion in the body opening for the door, distortion in the door itself, deflection in the thresholds of the floor).
Wear of holes and rods occurs as a result of rolling friction (axles and holes in door hinges) or loosening of the fastening of the assembly with rivets or bolts; wear of surfaces due to the systematic load applied to the surface, for example, when transporting loose abrasive goods in the bodies of dump trucks.
Structural flaws in body components often lead not only to damage, but complicate their repair, and sometimes repair operations, up to the need to replace the damaged unit with a new one. Structural flaws in the body, complicating its repair, take place mainly because automobile plants do not fully take into account the requirements of motor transport and auto repair enterprises for the body structure.
2.5.1 Body repair methods
Repair and assembly of bodies is carried out by two methods - stationary and in-line. With the stationary method of repair, the body is installed on the stand for the duration of the repair. The worker, having finished work on the body at one stand, moves to another. With the in-line method, the body in the process of repair is sequentially moved to specialized work stations, where a certain amount of work is performed in a limited time. Practice has shown that this method is the most effective, speeds up and improves body repair and has a number of advantages compared to the stationary one.
2.5.2 In-line method of body repair and assembly
The main advantages of the in-line method are the ability to place tools and devices in the immediate vicinity of the repaired bodies in the sequence of their application, and for workers to quickly perform the operations provided for by the process with minimal movements and labor costs; in increasing the repetition of operations and the specialization of workers in certain types of work, which makes it possible to achieve accuracy and perfection in their performance, to increase labor productivity.
A lot of repair and assembly operations performed on the body does not allow them to be stretched in one line territorially and alternate in time sequentially one after another. Therefore, a slow rhythm of the production line and the maximum combination of repair and assembly operations at one workplace are necessary so that the length of the flow line does not exceed the length of the production facilities. When choosing the number of work stations on the production line, it is necessary, in addition to the length of the tracks of the assembly department, to also take into account the staffing of the workforce, the strength, the capacity of utility departments and sections, as well as the need to arrange bodies at certain intervals, allowing you to perform the necessary work at each post.
Work on the repair and assembly of bodies can be carried out on a stream with moving or stationary bodies. The production line with fixed bodies is serviced by repair crews moving rhythmically along the work front from stand to stand, at each of which they perform the required operations. On a production line with movable bodies, the body moves along the work front, sequentially undergoing all the operations that are performed at a specific work station. At each post, the body is until the end of all the work planned for this post, and then moves to the next post (stand). This type of stream is the most productive.
The most rationally organized repair, in which the maximum possible number of parts and components of the body (cabin) that require repair or replacement, is repaired in advance in the relevant departments of the body shop or replaced with ready-made spare parts. This reduces to a minimum the number of repair operations on the production line and, consequently, the duration of the production cycle.
Repair and assembly of bodies are carried out on two parallel lines. On the first line - washing the body, removing the old paintwork, preliminary and final control, disassembly, repair and assembly of the body before painting; on the second - the setting of units, assemblies and parts on the body and its final finishing after painting. This construction of the process has justified itself in practice, since it allows the most rational use of production space. The number of disassembly posts, as well as posts for all other types of work (repair, assembly), depends on the plant program.
Various methods are used to install and move car bodies and cabs in the painting department: bodies (cabins) can remain on trolleys until the entire range of painting work is completed; when entering the painting department, the body (cabin) is installed on stationary stands (roller conveyors), the size of which does not exceed the overall dimensions of the body (cabin); cabins are hung from overhead conveyor or monorail trolleys mounted above all preparatory posts and passing through painting and drying chambers.
Sites for disassembly, repair and assembly of bodies are equipped with the equipment required for work and auxiliary devices designed to create convenience when using hand-held electric and pneumatic tools, storage of components and parts removed from the body or to be placed on it, etc.
2.6 Body repair methods
2.6.1 Repair by replacing damaged parts
Consider the processes of replacing the rear wing of a car after a general disassembly of the body, since this type of repair is most common in the practice of repair enterprises.
Figure 6 Replacing the rear wing of a passenger car: a - marking the cut line of the wing, b - cutouts on the flanges
The replacement of the rear wing welded to the car body is carried out as follows. Mark a cut line with a pencil or chalk along the entire perimeter of the old wing in such a way as to leave stripes 20–30 mm wide on the front of the wing, along the arch of the wheel opening and the upper part of the wing to its flange (Figure 6a). The old wing is carefully cut out according to the markings with a cleaning machine with a cutting abrasive wheel or a chisel and scissors for cutting sheet metal so as not to damage the internal parts of the body, reinforced to the body under the wing at the cutout points. If, after removing the old wing, the flanges of its upper part remaining on the body do not allow the new wing to be carefully fitted at the place of its attachment, these flanges are removed. The contact welding points are drilled from the side of the welded flange to the depth of its thickness and the flange is disconnected from the body using pliers or a thin sharp chisel. To drill out weld points, use a drill with a diameter of 6 mm, sharpened at an angle of 150 - 160°.After trimming the wing, carefully trim and clean to a metallic sheen the surfaces of the flanges to which the new wing is to be welded. On the latter, cutouts are made with a radius of 5–7 mm in increments of 40–50 mm along the entire perimeter to be welded (Figure 6b). Install and adjust the new wing at the attachment point and press it tightly with a clamp. Welding is carried out only along the edges of the bites in the following sequence: the upper front part is welded in three or four places, then the lower rear part from above in the area of the lantern, and then along the wheel arch, etc. until the final welding of the wing. In the process of welding and after its completion, the weld is forged with a hammer, using a support, and then the seam is carefully cleaned to a metallic sheen.
2.6.2 Straightening deformed panels and openings by mechanical action
As a rule, dents in body panels and plumage, where the metal is not stretched after impact, are leveled by extruding or pulling the concave section until it has the correct radius of curvature.
With a large stretching of the metal, bulges are formed that cannot be corrected by straightening. Bulge dressing can be done cold or hot. Cold bulge removal is based on stretching the metal along concentric circles or along radii from the bulge to the undamaged part of the metal (Figure 7). This forms a smooth transition from the highest part of the bulge to the surrounding surface of the panel.
Figure 7 Editing method (b) in body panels of bulges (a) without heating:
1 - bulge, 2 - panel, 3 - sections of the panel to be stretched by a hammer blow, 4 - radius of curvature of the panel after straightening the bulge, 5 - diagram of the direction of hammer blows (indicated by arrows)
Significant stretching of the metal, which occurs when removing the bulge by straightening in a cold state, increases the true surface of the metal in the area being repaired. As a result, the corrosion resistance of the metal deteriorates. Therefore, it is recommended to mechanically straighten uneven (wavy, small concave surfaces) metal body panels and plumage by smoothing with special devices, extruding or pulling using the following devices, and straightening bulges using heat.
To edit hard-to-reach places, curved support-blades are used (Figure 8a), the end of which can be inserted between the inner and outer body panels through gaps or mounting hatches (Figure 8b).
Figure 8 Supports(A) for editing areas covered with internal panels and a scheme for editing with their help the trunk lid (b): 1 - support,2 - inner panel, 3 - dent, 4 - straightening hammer, 5 - outer panel
Figure 9 Straightening minor dents on panels (roof, doors, hood, etc.)
To edit hard-to-reach places, curved support-blades are used (Fig. 8a), the end of which can be inserted between the inner and outer body panels through gaps or mounting hatches (Fig. 8b).
Straightening of minor dents on roof panels, doors, hood, trunk, fenders and other front panels and methods for its implementation are shown in Figure 9.
Correction of dents on bodies with a rounded (oval) front surface (Figure 10) always starts from the periphery of the dent and moves towards its center.
Figure 10 Sequence (1-9) for repairing dents on body parts with a rounded (oval) front surface
Elimination of small deformations in the panels in some cases can be done with the help of a clamping lever. Techniques for working with this tool, as well as with a hammer and a lever-clamp, are shown in Figures 10, 11.
Figure 10 Correction of the deformed area using the clamp lever
Figure 11 Repairing dents with a hammer and lever
When used for straightening small deformation areas of a special straightening hammer (has a notch) and an anvil-supportthe metal "does not float", its length is restored to its original shape and size.
To correct the distortions of the windshield opening, the doorway, hydraulic and screw extensions are used. Editing the deflection in the roof using stretching is shown in Figure 12a,and the skew in the doorway - in Figure 12b.
Figure 12 Editing the deflection in the roof (a) of the body and eliminating the skew in the doorway (b)
2.6.3 Dressing with heat
The essence of the thermal straightening method lies in the fact that the heated section of the panel in the process of thermal expansion encounters opposition from the surrounding cold metal. In progresscooling, the bulge decreases due to the fact that the areas heated around it, cooling, produce a tightening effect. As a rule, the heating zone should be located as close as possible to the top of the bulge. Heating is carried out in spots or stripes using an acetylene-oxygen burner to a temperature of 600 - 650°C. Spots up to 30 mm in diameter are oriented along the long sides of the bulge. Heating starts at a more rigid section and moves to a less rigid one. The distance between the centers of spots is 70 - 80 mm.
If the shape of the bulge approaches a spherical one, then the heating is carried out by crossing strips or a strip located along the slopes of the bulge. Each subsequent strip is heated after the previous one has completely cooled down. If there is free access to the bulge from the outer and inner sides of the panel, then heating can be combined with mechanical action to speed up the editing. At the same time, the most stretched part is heated with small spots and the blows of a wooden hammer around the heated spot “drive” the excess metal into this spot (Figure 13).
Figure 13 Scheme for straightening bulges in a heated state: 1 - approximate direction of hammer blows, 2 - heated spot, 3 - support,
4 - panel
2.7 Recovery of non-metallic parts
Non-metallic materials used in bodies include various plastics for decorative interior trim, as well as upholstery materials.
Damaged parts of bodies and cabs, for the manufacture of which plastic masses are used, are replaced with new ones during the repair process, since the technology for their manufacture is simple and economical. Parts for which it is feasible and economical to repair are usually repaired by bonding. The choice of adhesive for joining plastic materials depends on the chemical nature of the material, the working conditions of the adhesive joint and the technology of its application. For the manufacture of parts from plastics, etrol, polyamide, organic glass, nylon, etc. are used.
The gluing technology consists of the usual operations of surface preparation, application of glue and exposure of the adhesive composition under pressure. Parts made of etrol are glued with acetic acid, which is used to coat the surfaces to be glued, and then they are joined under slight pressure and held for 0.75-1 hour.
For gluing polyamides, solutions of polyamides in formic acid or formic acid are used. Parts made of plastic based on thermosetting resins are glued together neither by temperature, nor by moisture, nor by any chemical solvents. Ruptures in upholstery made of leatherette or PVC film, reinforced or not reinforced with a mesh of synthetic fibers, are eliminated by gluing the inserts with PEF-2/10 polyamide glue. Gluing is carried out at room temperature, followed by holding under pressure for 1-1.5 hours. For gluing new upholstery to cardboard, glue 88NP is used. The material for sewing new upholstery parts is cut according to markings or patterns using an electric knife. The upholstery parts to be joined are sewn with a certain stitch pitch at a given distance from the edges with a single or double seam from the non-front side of the upholstery. To increase the strength of the connection of the upper upholstery of the seat cushion, turning seams with piping are used. Stitched upholstery should not have a weak tightening, warps, wrinkles, folds and damage on the front side. To assemble the cushions and seat backs, a pneumatic stand is used, which allows you to compress the springs of the cushions to ensure material tension.
2.8 Repair of the main mechanisms and body equipment
The main mechanisms and equipment of bodies and cabs include locks, power windows and glass fastening mechanisms, seat frames, door and hood hinges, a heater heating system, etc. All parts of body mechanisms are relatively simple in design and their repair is reduced to performing simple metalwork and welding operations.
Existing cracks in the housings are welded, worn working surfaces are repaired by surfacing or processing to a repair size. Body parts with breaks are discarded. Broken springs and springs that have lost their elasticity are replaced with new ones. Broken screws in threaded connections are removed by turning them out, if it is possible to grab them by the protruding part, or by drilling a hole with a drill of a smaller diameter than the screw. A square rod is inserted into this hole, with which the rest of the screw is unscrewed. After removing the screw, the thread in the hole is driven with a tap. If the thread in the hole is damaged, then the hole is welded, the metal flows are cleaned from welding flush with the base metal of the body, a hole is drilled for the thread of the desired size and a new thread is cut. Loose rivets are tightened, and those that cannot be tightened are cut down and replaced with new ones. Destroyed cuffs, seals, sealing rings and gaskets are replaced with new ones. Minor deposits of corrosion on the surface of the parts are cleaned with sandpaper or a scraper and lubricated with kerosene. With deep traces of corrosion, damaged parts are replaced with new ones.
During the overhaul of bodies and cabs, the locks are completely disassembled. All parts are thoroughly washed in a bath of kerosene and wiped dry. After repairing parts or replacing them, the lock is assembled and adjusted.
The repair technology of power windows consists of their complete disassembly, washing, control, replacement of unusable parts with new ones, assembly and subsequent adjustment. Damaged glass doors are replaced with new ones.
The most typical seat frame defects include scratches, peeling of the chrome plating and corrosion on the surface of the upper part of the frame, deformation of the upper part of the frame, cracks and breaks in the bends and soldering points, curvature or breakage of the tabs of the frame fastenings to the floor and breakage of the backrest mounting brackets. To restore the decorative coating, chrome parts are removed and a new coating is applied. Broken soldering points are cleaned of old solder and other contaminants and re-soldered. Parts with cracks, breaks and other damage are separated by heating with a gas burner and replaced with new ones. The new parts of the frame are made of a seamless pipe with an outer diameter of 25 mm and a wall thickness of 1.5 mm.
Repair of hinges of doors and hoods consists in the elimination of curvature by straightening with a hammer on the plate, cracks and wear, welding, followed by machining, in the restoration of holes for repair dimensions. Loop parts that have broken parts are replaced with new ones.
2.9 Body assembly
The workflow of body assembly usually consists of assembly before painting and general assembly after painting. Fundamentally, the process of general assembly after painting the body during its repair is no different from the assembly of a new body, only the organizational forms of assembly and the ratio of the labor intensity of certain types of work change. The assembly of the body after a major overhaul must be carried out in the same sequence and with the same care as the assembly of a new body.
A characteristic feature of the assembly is that all the main shortcomings of the previous technological operations are found here. If they are made with a deviation from the technical specifications, then they produce additional processing, fitting and various kinds of finishing touches that affect the complexity and quality of the assembly.
When assembling bodies, serious attention is paid to the choice of tools and fixtures. In addition to universal tools and devices that can be used for any operation corresponding to their purpose (wrenches, screwdrivers, etc.), special tools designed to perform one very specific operation are also widely used. The use of special fixtures or tools simplifies and facilitates the assembly process.
The assembly of any body cannot be carried out in an arbitrary sequence. The assembly sequence is determined primarily by the design of the assembly being assembled, as well as the required division of assembly work. For clarity, it is customary to depict assembly diagrams in such a way that the corresponding components and parts are supplied in the order of their introduction into the assembly process.
Depending on the quality of the repair, the accuracy of manufacturing individual components and body parts, and the number of fitting works, there are three main types of assembly: according to the principle of complete interchangeability, according to the principle of individual fitting, and according to the principle of limited interchangeability. Assembly according to the principle of complete interchangeability is used mainly in mass and large-scale production. In small-scale production, and even more so in single-piece production, the principle of complete interchangeability is not economically justified and therefore it is applied only in individual cases. Assembly according to the principle of individual fit, the purpose of which is to give the details the exact dimensions or one or another geometric shape, is carried out by fitting the parts to be joined to each other. This operation is usually very complex and time consuming, so in advanced auto repair plants, the custom-fit assembly is gradually being replaced by a more advanced limited interchangeability assembly.
The most common types of fitting work when assembling a body are works related to the installation of parts and assemblies removed from the body and subjected to repair or newly manufactured; filing; drilling and reaming holes in place; thread cutting; sweep; bending. The mechanization of fitting work during assembly is carried out mainly through the use of universal and specialized tools with electric and pneumatic drives.
Assembly of bodies prior to painting is usually associated with a significant amount of fitting work and is carried out at the body repair shop. Prior to painting, pre-primed doors, front and rear fenders, hood, radiator lining, mud flaps, trunk lid and other parts to be painted together with the body are installed on car bodies before painting.
The assembly of the body after painting is carried out in the reverse order of the disassembly of the bodies.
III. Safety and labor protection
3.1 General provisions for occupational safety
Occupational safety is understood as a system of legislative acts and corresponding measures aimed at maintaining the health and working capacity of workers.
The system of organizational and technical measures and means to prevent industrial injuries is called safety engineering.
The system of organizational, hygienic and sanitary-technical measures and means to prevent the incidence of workers is called industrial sanitation.
The main provisions on labor protection are set out in the Labor Code (Labor Code).
One of the main measures to ensure labor safety is the mandatory briefing of newly hired and periodic briefing of all employees of the enterprise. The instruction is given by the chief engineer. Newly hired people are introduced to the basic provisions on labor protection, internal regulations, fire regulations and features of the enterprise, the obligations of employees to comply with safety regulations and industrial sanitation, the order of movement at the enterprise, protective equipment for workers and methods of providing first aid to victims.
3.2 Process requirements
During the maintenance and repair of vehicles, it is necessary to take measures against their independent movement. Maintenance and repair of vehicles with a running engine (except for engine adjustments) is prohibited.
Handling equipment must be in good working order and used only for its intended purpose. This equipment must only be operated by persons who have been properly trained and instructed.
During disassembly and assembly of components and assemblies, it is necessary to use special pullers and keys.
It is forbidden to clutter up passages between workplaces with parts and assemblies, as well as to accumulate a large number of parts at disassembly sites.
The operations of removing and installing springs represent an increased danger, since significant energy has been accumulated in them. These operations must be carried out on stands or with the help of devices that ensure safe operation.
Hydraulic and pneumatic devices must be equipped with safety and bypass valves. The working tool must be in good condition.
3.3 Requirements for work premises
The premises in which the worker must be under the vehicle must be equipped with inspection ditches, overpasses with guide safety flanges or lifts.
Supply and exhaust ventilation must ensure the removal of released vapors and gases and the supply of fresh air.
Workplaces must be provided with natural and artificial lighting sufficient for the safety of work.
Sanitary facilities must be equipped on the territory of the enterprise: dressing rooms, showers, washbasins (with the obligatory presence of hot water when working with leaded gasoline).
IV. Conclusion
In this course work, the technological process of repairing car bodies is considered. Body malfunctions, as well as the process of defect detection of parts and methods for eliminating defects, are considered in detail, measures for labor protection and safety during repair work are considered.
V. Bibliography
1. "Car Repair" S.I. Rumyantsev M. transport 1990-327 p.
2. Reference technologist machine builder volume 2 M. mechanical engineering 1988-240s.
3. Fundamentals of automotive technology and car repair M. mechanical engineering 1991-315 p.
4. E.S. Kuznetsov. Technical operation of cars. Moscow. Transport, 1991.
5. Labor protection at motor transport enterprises Salov F.M. M.: 1991
6. F.N. Avdonkin "Maintenance of automobiles" M .: "Transport" 1988 p. 271
7. Device, maintenance and repair of cars. : a textbook for the beginning. prof.: S.K. Shestopalov.- M.: "Academy" 2006-566s.
8. "Maintenance and car repair" L.I. Epifanov. 2004
9. “Car repairman” A.S. Kuznetsov 2006
10. "Maintenance and repair of vehicles" V.M. Vlasov 2004
