MAINTENANCE AND REPAIR OF KAMAZ VEHICLES

GENERAL INFORMATION ABOUT MAINTENANCE

The scope of maintenance includes control and diagnostic, fastening, lubrication, adjustment, electrical and assembly and disassembly work related to the testing and adjustment of individual components and assemblies on special stands and equipment.

If during maintenance there is doubt about the full serviceability of a separate assembly unit, then check it with a special device or on a stand.

TYPES OF MAINTENANCE OF KAMAZ VEHICLES

Maintenance cars (road trains) KamA3 is subdivided into service in the initial and main periods of operation.

Maintenance during the initial period of operation:

Daily maintenance;

Maintenance after the first 1000 km (service A);

Maintenance after the first 4000 km (service B);

Service 1 after the first 8000 km;

Service 2 after the first 12,000 km.

Maintenance during the main period of operation: Table 1

Frequency of vehicle maintenance

Daily maintenance;

Service 1;

Service 2;

Seasonal maintenance (service C).

The main purpose of daily maintenance is the general monitoring of the condition of units and systems that ensure traffic safety, and maintaining proper appearance.

In the initial period of operation, the parts in the vehicle units are run in, therefore, when carrying out maintenance during this period, perform preventive fastening and lubrication and cleaning work with special care.

Maintenance in the initial period is carried out regardless of operating conditions.

During the main period of operation, maintenance work is carried out at intervals corresponding to the category of operating conditions (Table 1).

Seasonal maintenance includes additional fall maintenance that is performed once a year.

All types of maintenance are carried out within the time specified in the service book.

LUBRICATION

The name of the oils, the quantity and frequency of lubrication are indicated in the chemotological map of vehicle lubrication (Appendix 4), and the location assembly units and units that require periodic replenishment or replacement of oil, is shown in fig. 289.

Remember that the use of substitutes significantly reduces the durability of vehicle assembly units (for example, power steering - by three to four times) and is only allowed as a temporary measure.

When switching from one recommended type of oil to another, flush the gearbox with a mixture of 50% diesel fuel and 50% fresh, intended for subsequent oil filling, cranking the engine for 5...10 min with neutral in the gearbox.

FASTENING WORKS

The list of maintenance operations (see appendix 2) provides for fixing work, the implementation of which is mandatory. To control the execution of fastening work, Appendix 7 contains a table of tightening torques for threaded connections tightened during maintenance.

FEATURES OF REPAIR WORKS

The current repair of the car consists in the elimination of malfunctions and damages detected during operation or maintenance by means of repair

operations associated with partial or complete disassembly of units, assembly units or their replacement, as well as with the replacement of individual parts (except for basic ones). The base part of the unit is the most complex and expensive part (body, base, frame, block, etc.), to which all other parts are attached.

Before dismantling the unit (engine) or any assembly unit located on it, check the general condition of the unit (engine) using diagnostic equipment and collect as much data about him as possible. This will help determine the cause of the problem.

For a faster and more thorough check, the unit (engine) must be cleaned of dirt and washed before inspection. Remove, transport and install the unit (engine) using lifting and transport vehicles equipped with devices that guarantee complete safety of work.

When performing repair operations, be guided by the following general principles. Disassemble and assemble parts of any assembly unit or unit on a special stand or workbench, using special tools and fixtures, a list of which is given in Appendix 10.

Assemble all assembly units and assemblies in the reverse order of disassembly. Therefore, when disassembling, arrange the parts in a certain order.

Parts connected by welding, riveting or fixed fits, disassemble only in cases where this is caused by repair conditions. Unscrew the studs only when it is necessary for the disassembly of the unit or assembly unit, when replacing the stud and part.

Before tightening the cylinder head bolts (if removed), remove oil or water from the threaded holes in the block.

Do not depersonalize pairs of parts that are installed on the engine only as a set: main bearing caps with a block, connecting rods with connecting rod caps, plunger pairs fuel pump high pressure, piston with cylinder of manual fuel priming pump, rod with bushing of low pressure fuel pump rod; driven and driving gears, main gear drive axle gearboxes.

Carefully separate the gaskets from the contact planes with a screwdriver; extrude the parts only with the help of tools, if they are not available, with the help of special drifts or with light blows of a copper (wooden) hammer.

To check the technical condition, clean all parts after disassembly from dust, scale, soot, varnish deposits, rust, rinse and dry. Do not wash parts made of aluminum and zinc alloys in alkaline solutions.

Control of parts, start with an external inspection, to identify defects on critical parts, use magnifiers or a magnetic flaw detector. Demagnetize the parts that have been tested on a magnetic flaw detector.

When inspecting, discard:

Parts with significant scuffing, spalling or chipping, traces of burning;

Parts with cracks on working surfaces and in places that experience heavy loads during operation (for example, cracks on crankshafts and connecting rods are unacceptable);
- fasteners with thread damage of more than two threads;

Bolts and nuts with worn edges, as well as screws with clogged or torn head slots;

Splint wire and lock washers with folding edges;

Rubber parts that have lost elasticity;

Hoses with cracks and bundles;

Pipelines with dents that reduce their cross section, or with cracks at flared ends;

Crumpled brass couplings;

Metal panels and plumage parts with dents, cracks and holes on the surfaces;

Fuel tanks with dents, leaks, coating or paint damage.

Before assembly, prepare all parts as follows:

Clean out nicks and burrs on mating surfaces of parts;

Restore the thread damaged within acceptable limits;

Weld cracks or shells in unloaded parts of parts (for example, in the walls of water jackets and exhaust gas pipelines); after welding, clean the seams to give the part the proper appearance;

Parting planes, in which warpage slightly exceeds the allowable level, correct with a scraper;

Check for tightness water and oil cavities of parts and assembly units, as well as high and low pressure fuel lines;

Remove the anti-corrosion coating used when storing parts;

Wash the parts and assemblies of the high-pressure fuel pump, hand pump and nozzles with clean summer diesel fuel, precision parts (plunger pairs, pressure valves and sprayers) with gasoline. After washing, blow the parts with compressed air.

Don't wipe parts fuel equipment cleaning material.

Before assembly, lubricate sealing gaskets, threads in holes for plugs and threads in through holes with sealing non-drying paste, and impregnate felt seals with grease.

By readiness for assembly, it is understood that all assembly units to be restored have been restored or replaced with new ones and are ready for assembly. During the assembly work, inspect each mechanism and make sure that nothing was missed during the restoration.

Assemble under conditions that guarantee the cleanliness of the parts.

When tightening joints sealed with rubber gaskets, do not apply too much force, otherwise the gaskets will be destroyed. Tighten threaded connections during assembly, providing the torques recommended in Appendix 7.

When pressing in rolling bearings, the tool must rest against the ring to be pressed in.

At installation of epiploons and cuffs use mandrels.

After repairing assembly units and replacing them on the car, run in to make sure that all mechanisms and systems are in good condition and that their interaction is correct.

SAFETY REQUIREMENTS

When placing a car for repair, brake it using the parking brake system, shift into a low gear, turn off the fuel supply and put stops (shoes) under the wheels;

Do not carry out any work on a car hung out on the same lifting mechanisms (jacks, hoists, etc.);

Do not repair the vehicle with the engine running, except for checking the operation of the engine and brakes;

When starting the engine, take precautions: first make sure that the gear lever is in the neutral position and there is no one in front of the car; give a warning signal before starting the engine;

When replacing units, remove, transport and install the engine, gearbox, drive axles, drive axle gearboxes using lifting and transport mechanisms equipped with devices (grabs) that guarantee complete security works. Do not lift (hang out) the vehicle by the tow hooks;

Do not remove, install or transport the units when mooring them with a cable and a rope without special grips;

When removing the engine, gearbox, intermediate and rear axles, first drain the oil into a special bowl;

When working under an overturned vehicle cab, be sure to lock the position of the limiter with the latch. When lowering the cab, make sure that the locking mechanism is securely closed and correct installation safety hook in the groove of the support beam;

When removing and installing springs on cars, first unload them from the weight of the car by lifting it by the frame with a lifting mechanism
with subsequent setting on the tragus;

Do not start dismantling the tires until the air is completely released from them;

Inflate tires after assembling the wheel in a special guard that protects against injury if the lock ring accidentally pops out of the rim groove. When inflating tires on the road, place the wheel with the key ring down;

If it is necessary to work under a raised unloaded platform of the Ka-mA3-55111 dump truck, lock the platform with locking pins. Do not work under a raised, loaded platform of a dump truck;

Wear goggles, rubber gloves, rubber boots and an apron made of acid-resistant material when preparing the electrolyte, and also before pouring electrolyte into the batteries;

To prepare the electrolyte, use dishes resistant to the action of sulfuric acid (ceramic, plastic, lead);

Do not pour water into concentrated sulfuric acid;

If sulfuric acid is accidentally splashed on the skin, immediately, before medical attention, remove the acid with a clean rag; wash the affected areas with a stream of water and then with a neutralizing solution of ten percent ammonia or soda ash;

When inspecting batteries during maintenance, do not use open fire (matches, candles, etc.);

Do not lean over the batteries while charging;

When working with metal tools, do not allow short circuits by simultaneously touching the battery terminals of different polarities;

Do not dismantle spring brake chambers without a press or special tool.

Note.
Checking the performance of the pneumatic brake drive
the car is made using standard instruments in the cab
driver (two-pointer pressure gauge, brake display) and
control pressure gauges for control output valves, which
installed in all brake circuits, and
connecting heads type "Palm" and type "A". valves
The test outlet is located in the following locations:
- front axle service brake drive circuit - on the valve
pressure limiter;
- the circuit of the drive of the service brakes of the rear bogie - on the left
(in the direction of the vehicle) frame side member in the area of ​​the rear axle;
- auxiliary and spare brake drive circuits - on
right side member of the frame in the area of ​​the rear axle and the air tank
contour;
- auxiliary brake drive circuit and consumers -
in the air tank of the circuit.
Functionality check should be carried out after
elimination of air leaks in the pneumatic system.

Check sequence

1. Connect test gauges to valves
control output and connecting heads.
2. After starting the engine, fill the pneumatic system with air.
After the pressure regulator has actuated, the pressure in all
circuits of the brake drive and the connecting head of the supply

0.62 - 0.75 MPa (6.2 - 7.5 kgf / sq. cm). Pressure in
connection head type "A" must be within
0.48 - 0.53 MPa (4.8 - 5.3 kgf / sq. cm). Pilot lamps
the brake indicator should not light up.
With the extinction of the last lamp, the buzzer should stop
work.
3. Fully depress the service brake pedal. Pressure over
two-pointer pressure gauge in the driver's cab should sharply
decrease by no more than 0.05 MPa (0.5 kgf / sq. cm). Wherein
pressure in the control output valve of the working drive circuit
brakes of the front axle at the beginning of the pedal stroke should increase
slowly, and with the pedal fully depressed, it should equalize with
pressure indicated by the upper scale of the two-pointer
pressure gauge. Pressure in the control outlet valve of the circuit
drive service brakes of the middle and rear axles (with
fully depressed pedal) should be at least 0.25 MPa (2.5
kgf/sq. cm) (for an unladen vehicle). When raised up
vertical linkage of the brake force regulator drive by the value
static stroke (suspension deflection 50 - 55 mm) pressure in
brake chambers of the rear bogie should be equal to the pressure
indicated by the lower scale of a two-pointer manometer. Pressure
in the head type "A" should decrease to 0. The pressure in the head
type "Palm" of the brake line of the two-wire actuator must
rise to a value of 0.62 - 0.75 MPa (6.2 - 7.5 kgf / sq. cm).
4.Handle operated reverse action valve
install the parking brake actuator in the front fixed
position. Pressure in the control outlet valve of the circuit
parking and emergency brakes must be equal
pressure in the air tank of the parking and spare circuit
brakes and be within 0.62 - 0.75 MPa (6.2 - 7.5
kgf/sq. cm).
Wherein:
- the pressure in the connection head type "A" must be in
within 0.48 - 0.53 MPa (4.8 - 5.2 kgf / sq. cm);

2-wire drive line must be set to 0.
5.Handle operated reverse action faucet
put the parking and spare brakes in the rear
fixed position.
Wherein:
- the control lamp should be on in a flashing mode;
- pressure in the control output valve of the drive circuit
parking and spare brakes and coupling head type
"A" should decrease to 0;
- pressure in the connecting head type "Palm" brake
line of the 2-wire actuator must be within
0.62 - 0.75 MPa (6.2 - 7.5 kgf / sq. cm).
6. With the position of the crane handle (reverse action with manual
control) in the rear fixed position, press the button
emergency release. At the same time, the pressure in the valve
control output of the parking and spare drive circuit
brake pressure must be equal to the pressure shown
two-pointer pressure gauge in the driver's cab. Brake rods
cameras must be removed.
Release the emergency release button. Air pressure
in the cavities of spring energy accumulators should decrease to 0.
7. Press on the edges of the auxiliary brake. stocks
pneumatic cylinders for controlling the dampers of the engine brake and
the fuel cut-offs should slide out. At the same time, the pressure
air in the brake chambers of the trailer (semi-trailer) must be
equal to 0.06 MPa (0.6 kgf / sq. cm).
8. In the process of checking the operability of the pneumatic system of the lamp
brake display should light up and should start working
buzzer when pressure drops in the corresponding circuit below
0.48 - 0.52 MPa (4.8 - 5.2 kgf / sq. cm).

Introduction

The goals and objectives of the graduation project is to sum up the disciplines passed during the training in this educational institution. Show your knowledge and skills in the organization of the production program for maintenance and repair, received during the training.

He will learn how to practically calculate the production program for maintenance and TR, calculate the staff for performing work, calculate the number of maintenance and TR posts for the optimal operation of a motor transport enterprise, calculate the economic costs for the operation of the enterprise and the energy costs of the enterprise, and also learn how to choose the right equipment and rationally arrange him at work.

The introduction of new methods of organizing production aimed at increasing labor productivity, the quality of work, and reducing labor intensity. In our time, modern motor transport enterprises need thorough mechanization of repair zones, lines, sections. If the mechanization of these zones, lines, sections is changed, then this will greatly increase labor productivity and the quality of technical interventions for maintenance and repair. Consequently, trucking companies receive a large economic benefit, since it will be possible to reduce the number of workers. Mechanization will reduce the labor intensity of the work performed, because manual labor will be minimized.

The state of the organization of maintenance and repair in modern conditions is at a low level of mechanization. This leads, as mentioned above, to a decrease in labor productivity and an increase in the labor intensity of the work performed. At the same time, the role and importance of road transport in the transport system is constantly increasing. Characteristic for road transport at the present stage of development is the concentration of rolling stock in the system of general use of transport, the consolidation of motor transport enterprises and their specialization by type of transportation or by type of rolling stock. For example: taxi fleet. In our country, MOT and TR of cars is carried out on a planned basis, which is a system of MOT and repair, which consists of a set of interrelated provisions and norms that determine the procedure for carrying out maintenance and TR work in order to ensure the specified quality indicators of cars during operation. On the road transport most countries also use a preventive system, and is carried out regularly after a certain mileage (hours) of the car, and repairs, as a rule, are performed on demand, i.e. after a malfunction or failure occurs.

The fundamental foundations of the organization and standards of MOT and TR are regulated in our country by the "Regulations on the maintenance and repair of rolling stock of road transport", which is the result, firstly, of the ongoing scientific research in the Minavtotrans system in the field of technical operation of vehicles, and secondly, experience advanced motor transport enterprises; thirdly, the work carried out by the automotive industry to improve the quality of cars. But unfortunately it was released in the nineties, and there is no update that is so necessary now

The production and technological base of road transport, the purpose of which is to ensure the requirements for the normal technical operation of the rolling stock and, first of all, should ensure its performance and reliability, including a complex of enterprises and structures (garages, centralized service bases, repair plants, workshops, etc.). ).

The totality of enterprises and facilities, together with the rolling stock, forms the fixed assets of road transport, the effective use of which is the main task in the field of road transport

The main requirement is to provide high technical level and high economic efficiency of the projected enterprise, buildings and structures by using the latest achievements of science and technology, so that the designed and reconstructed enterprises by the time they are put into operation are technically advanced and have high rates of productivity and working conditions, the level of mechanization in production activities , the cost of production quality, as well as the efficiency of the use of capital investments.

The construction of new motor transport enterprises is carried out, as a rule, according to standard projects intended for repeated use in similar conditions, i.e. typical for this class of enterprises. Such projects are based on the use in construction of standard standard parts, structures and materials produced in mass quantities by construction industry enterprises. Typical design is also of some importance in terms of the operation of enterprises, provided that the most advanced production methods, technological processes were laid down in the project, the composition and size of production facilities, the latest models of technological equipment, etc. were justified.

1.2 General

1.2.1 The value of the type of maintenance (TR) in the activities of the ATP

The task of TO-1 and TO-2 is to reduce the intensity of changes in the parameters of the technical condition of the mechanisms and assemblies of the car, to identify and prevent malfunctions, to ensure the efficiency of work, traffic safety, and environmental protection by timely performance of control, lubrication, fastening, adjustment and other work. Diagnostic work (diagnosing process) is a technological element of vehicle maintenance and repair (control operations) and provides information about its technical condition when performing appropriate work.

Depending on the purpose, frequency, list and place of performance, diagnostic work is divided into two types: general (D-1) and element-by-element in-depth (D-2) diagnostics. Maintenance should ensure the trouble-free operation of the units, components and systems of the vehicle within the established intervals for those effects that are included in the list of operations.

The task of seasonal maintenance, carried out 2 times a year, is to prepare the rolling stock for operation when the season (season) changes.

As a separately planned type of maintenance, SA is carried out for rolling stock operating in very cold, cold, hot dry and very hot dry climatic regions.

Labor intensity standards for CO are 50% of the labor intensity of maintenance for very cold and very hot dry climatic regions; 30% for cold and hot dry areas; 20% for other areas. In other conditions, it is combined with the next TO 2 with an increase in labor intensity compared to the labor intensity of TO-2 by 20%. overhaul. The characteristic works of TR are: dismantling, assembly, metalwork, welding, troubleshooting, painting, replacement of parts and assemblies. With the TR of the unit, it is allowed to replace parts that have reached the limit state, except for the basic ones. In a car during TR, individual parts, mechanisms, assemblies that require current or major repairs can be replaced.

The TR must ensure the trouble-free operation of the repaired units and assemblies for a run not less than before the next TO-2. In the current system for TR, the specific labor intensity is regulated, i.e., the labor intensity related to the vehicle mileage (man-hours / 1000 km), as well as the total specific downtime in TR and TO (days / 1000 km). In addition, special standards regulate maintenance costs (rubles / 1000 km) with an element-by-element breakdown into labor, spare parts and materials.

The regulation on maintenance and repair and the corresponding practice indicate the expediency of regulating a number of TR works (preventive maintenance), for example, to prevent failures that affect traffic safety or give large losses when they occur. Some of these operations are TR. low labor intensity can be combined with TO (associated TR).

Overhaul is intended for the regulated restoration of vehicles and their units that have lost their working capacity, ensuring their resource until the next overhaul or writing off at least 80% of the norms for new vehicles and units.

Overhaul of the unit provides for its complete disassembly, defect detection, restoration or replacement of parts with subsequent assembly, adjustment and testing. The unit is sent for overhaul in cases where the base and main parts (Table 6.4) need to be repaired, requiring a complete disassembly of the unit, and also when the unit's operability cannot be restored by carrying out the TR.

The main details ensure the performance of the functional properties of the units and determine their operational reliability. Therefore, the restoration of the main parts during a major overhaul should provide a level of quality close to or equal to the quality of new products.

The base or body parts include parts that form the basis of the unit and ensure the correct placement, relative position and functioning of all other parts and the unit as a whole. The operability and maintainability of the base parts, as a rule, determine the full service life of the unit and the conditions for its decommissioning.

1.2.2 List of technological impacts on the car

Engine, including cooling systems, lubrication: work performed during the first maintenance

1. Check by inspection the tightness of the lubrication, power and cooling systems of the engine (including the starting heater), as well as the attachment of equipment and instruments to the engine.

2. Check the condition and tension of the drive belts.

3. Check the fastening of the parts of the exhaust tract (downpipe, muffler, etc.).

4. Check motor mounting.

Engine, including cooling systems, lubrication, diesel power supply system: control and diagnostic, fixing and adjustment work performed during the second maintenance

1. Visually check the tightness of the engine cooling system, heating system and starting heater.

2. Check the condition and operation of the blinds (curtains), radiator, thermostat, drain cocks.

3. Check the fastening of the radiator, its lining, blinds, hood.

4. Check the fastening of the fan, water pump and timing gear cover (chain, belt).

5. Check the condition and tension of the drive belts.

6. Visually check the tightness of the lubrication system.

7. Check the fastening of the engine cylinder heads and the racks of the rocker axles.

8. Check clearances between valve stems and rocker arms.

9. Check the fastening of the muffler pipelines.

10. Check the fastening of the engine oil pan, speed controller crankshaft.

11. Check the condition and fastening of the engine mounts.

12. Check fastening and tightness fuel tank, pipeline connections, fuel pumps, injectors, filters, drive couplings.

13. After one TO-2, remove and check the nozzles on a special device.

14. To check up serviceability of the mechanism of management of giving of fuel.

15. Check engine stop action.

16. Check the fuel circulation and pressurize the system if necessary.

17. Check the reliability of starting the engine and adjust the minimum speed of the crankshaft in the mode idle move.

18. Check the operation of the engine, high pressure fuel pump, crankshaft speed controller, determine the smoke of exhaust gases.

19. After one TO-2, check the fuel injection advance angle.

20. Check the oil level in the high pressure fuel pump and engine speed control.

21. Drain sediment from oil filter housings.

22. Clean and flush the crankcase ventilation valve.

23. Rinse the filter element air filter engine and compressor; change their oil.

24. Change (according to the schedule) the oil in the engine crankcase, while washing the filter element of the filter coarse cleaning and replace the filter element fine cleaning oil or clean the centrifugal filter. Remove and clean the fuel sediment filter and fuel fine filter. For vehicles with a diesel engine, remove and wash the housings of the pre- and fine fuel filters and replace the filter elements.

25. Inspect and, if necessary, clean the fuel pump sump from water and dirt.

Work performed on the engine and its systems during seasonal maintenance (SO)

1. In addition to the work provided for by the second maintenance, perform the following.

2. Flush the engine cooling system.

3. Check the condition and operation of the valves of the cooling system and drain devices in the power and brake systems.

4. Flush the fuel tank and blow out the fuel lines (in autumn).

5. Remove the carburetor and fuel pump, rinse and check the condition and operation on the stand (autumn).

6. Remove the high pressure fuel pump, rinse and check the condition and operation on the stand (in autumn).

7. Remove the breaker-distributor, clean, check the condition and, if necessary, adjust on the stand.

8. Check the serviceability of the sensor for switching on the clutch of the cooling system fan and the alarm sensors for the liquid temperature in the cooling system and oil pressure in the lubrication system.

9. Check the tightness of the closure and completeness of the opening of the radiator shutters.

Typical damage to the crank mechanism (KShM) includes: cylinder wear, piston rings, grooves, walls and holes in the piston bosses, piston pins, bushings of the connecting rod heads, necks and liners of the crankshaft; coking of rings, characteristic failures - breakage of piston knees, scuffing of the cylinder mirror and jamming of pistons, melting of bearings, appearance of block cracks

cylinders

The main signs of a KShM malfunction are: a decrease in compression in the cylinders, the appearance of noise and knocks during engine operation, a breakthrough of gases into the crankcase and an increase in oil consumption, contamination of spark plugs with oil. This will usually try to reduce the fuel consumption of the engine power.

Typical damage to the gas distribution mechanism (GRM) includes: wear of the pushers of their guide bushings, valve plates and their sockets, gears, cams and bearing journals camshaft; violation of the gaps between the valve stems and rocker arms (pushers), breakage and loss of elasticity of the valve springs, breakage of the teeth of the distribution gears, burnout of the valves. Signs of a timing failure are knocking, flashes in the carburetor and pops in the muffler.

Maintenance of KShM and timing. It is part of the engine maintenance and includes checking and tightening the fasteners, engine diagnostics, adjustment and lubrication work.

Mounting work is carried out to check the condition of the fasteners of all engine connections; engine mounts to the frame, cylinder heads and oil pan to the block, inlet and outlet pipe flanges and other connections.

To prevent the passage of gases and coolant through the cylinder head gasket, check and, if necessary, tighten the nuts securing it to the block with a certain moment. This is done using a torque wrench. Torque and tightening sequence of nuts are factory set. Cast iron cylinder head. Checking the tightening of the crankcase mounting bolts in order to avoid its deformation and leakage is also carried out in compliance with a certain sequence, which consists in alternately tightening the diametrically located bolts.

Diagnostics of the technical condition of the crankshaft and timing at motor transport enterprises is carried out: by the amount of gases breaking through the crankcase; by pressure at the end of the compression stroke (compression), by leakage of compressed air from the cylinders, by listening to the engine with a stethoscope.

The amount of gases breaking through into the crankcase between the pistons with rings and cylinders is measured by a gas flow meter connected to the oil filler pipe. At the same time, the engine crankcase is sealed with rubber plugs that close the holes for oil dipstick and gas outlet pipe of the crankcase ventilation system. Measurements are made on a dynamometer at full load and maximum crankshaft speed. For a new engine, the amount of blow-by gases, depending on the engine model, is 16-28 l/min. Despite the simplicity of the method, its use in practice encounters difficulties associated with the need to create a full load and a variable amount of bursting gases, depending on the individual qualities of the engine.

Most often, the diagnosis of KShM and timing is carried out with a compressometer by measuring pressure at the end of the compression stroke, which serves as an indicator of tightness and characterizes the condition of cylinders, pistons with rings and valves -

The most advanced method for determining the condition of the crankshaft and timing belt is using a special device for leaking compressed air, forcibly supplied to the cylinder through the hole for the candle.

Listening with a stethoscope to noises and knocks, which are the result of a violation of the gaps in the interfaces of the crankshaft and timing, also allows you to diagnose the engine. However, this requires a lot of practical experience of the performer.

Adjustment work is carried out after diagnosis. If a knock is detected in the valves, as well as during TO-2, they check and adjust thermal gaps between the ends of the valve stems and the toes of the rocker arms. When adjusting the clearances on the ZMZ-53 engine, the piston of the 1st cylinder on the compression stroke is set to TDC, for which the crankshaft is rotated until the duckweed on its pulley is aligned with the central risk on the indicator located on the timing gear cover. In this position, the gaps between the valve stems and the toes of the rocker arms of the 1st cylinder are adjusted. The clearances at the valves of the remaining cylinders are adjusted in the sequence corresponding to the order of operation of the cylinders: 1-5-4-2-6-3-7-8, turning the crankshaft 1/4 turn when moving from cylinder to cylinder. There is another way to adjust the gaps. So, in the ZIL-130 engine, after installing the piston of the 1st cylinder at TDC, for which they combine the hole in the crankshaft pulley with the TDC mark, first adjust the gaps at both valves of the 1st cylinder, exhaust valves of the 2nd, 4th and 5th cylinders , inlet valves of 3, 7 and 8 cylinders. The clearances of the remaining valves are adjusted after turning the crankshaft a full turn.

To adjust the clearances in the KamAZ-740 engine, the crankshaft is set to the position corresponding to the beginning of the fuel supply in the 1st cylinder, using a latch mounted on the flywheel housing. Then the crankshaft is turned through the hatch in the clutch housing by 60 ° and the valve clearances of the 1st and 5th cylinders are adjusted. Next, turn the crankshaft 180, 360 and 540 °, adjusting the clearances in the 4th and 2nd, 6th and 3rd, 7th and 8th cylinders, respectively,

It is easy to see that, regardless of the method of installing the crankshaft in the initial position for adjustment, the thermal gap in the drive of each valve is checked and adjusted in the position when this valve is completely closed,

Current repair of crankshaft and timing gear, Typical works during the current repair of crankshaft and timing gear are the replacement of liners, pistons, piston rings, piston pins, connecting rod and main bearing shells, valves, their seats and springs, tappets, as well as grinding and lapping of valves and their seats .

Replacement of cylinder block liners is carried out in cases where their wear exceeds the allowable, in the presence of chips, cracks of any size and scoring, as well as in case of wear of the upper and lower landing belts.

Removing the liners from the cylinder block is quite difficult. Therefore, they are pressed in with the help of a special puller, the grips of which are hooked on the lower end of the sleeves. The use of other methods is unacceptable, as this leads to damage to the mounting holes for the liners in the engine block and the liners themselves.

Before pressing in a new liner, it must be selected along the cylinder block so that its end protrudes above the plane of the connector with the block head. To do this, the sleeve is installed in the cylinder block without sealing rings, covered with a calibration plate and the gap between the plate and the cylinder block is measured with a feeler gauge.

Sleeves installed in the block without o-rings must rotate freely. Before the final installation of the liners, the condition of the bores under them in the cylinder block should be checked - If they are severely corroded or have shells, it is necessary to repair them by applying a layer of epoxy mixed with cast iron filings, which, after hardening, should be cleaned flush. The edges of the upper part of the block, which are the first to come into contact with the rubber o-rings when pressing the sleeve, must be cleaned with sandpaper to prevent damage to the o-rings during the pressing process,

Liners with rubber sealing rings installed on them are pressed into the cylinder block using a press. You can do this with the help of a special device, a device. When putting on the sealing rings, they must not be strongly stretched, and also twisted in the groove of the cylinder liner.

The pistons are replaced when deep burrs form on the surface of the skirt, the bottom and the surface of the piston in the area of ​​the upper compression ring burn out, and when the upper groove for the piston ring is worn more than allowed.

The piston is replaced without removing the engine from the car: the oil is drained from the oil pan, the head of the block and the oil pan are removed, the cotter pins and nuts of the connecting rod bolts are unscrewed, the cover of the lower head of the connecting rod is removed and the damaged piston assembly with the connecting rod and piston rings is pulled up. Then the retaining rings are removed from the holes in the bosses, the piston pin is pressed in with a press and the piston is separated from the connecting rod. If necessary, the bronze bushing of the upper head of the connecting rod is pressed in with the same press.

Before replacing a piston, you must first select it according to the cylinder, To do this, select a piston whose size group corresponds to the size group of the sleeve (cylinder), and check the gap between the piston and sleeve with a feeler tape, To do this, insert the piston into the cylinder head down so that the edge skirts coincided with the end of the sleeve, and the probe tape inserted between the sleeve and the piston. was in a plane perpendicular to the axis of the finger. Then, the probe tape is pulled with a dynamometer and the pulling force is measured, which should be within the allowable range. The dimensions of the probe tape and the pulling force for different engine models are given in the operating instructions or in the repair manual. So, for ZIL-130 engines, a tape 0.08 mm thick, 13 mm wide and 200 mm long is used, and the pulling force should be 35-45 N. If the force is different from the recommended one, take another piston of the same size group or, as excluded neighboring size group and again pick it up on the cylinder.

Within the nominal and each repair size of the liners and pistons of the ZIL-130 engine, there are six size groups. The diameters of the cylinders within each of them differ by 0.01 mm. The index of the size group (A. AA, B, BB, C, BB for liners and pistons of nominal size and G, YY, D. DD, E, EE for the 1st repair size, etc.) is indicated on the upper end of the sleeve and on the bottom of the piston,

All other car engines have similar size groups within each repair size.

When assembling engines, removed; from a car, the selection of pistons for cylinders is carried out in a similar way, pistons are also selected when assembling engines at manufacturers.

When replacing pistons with ATP, except for the piston sub-6opa along the cylinder, one more important requirement of the specifications for engine assembly should be observed: the diameter of the hole in the piston bosses, the diameter of the piston pin and the diameter of the holes in the bronze bushing of the upper connecting rod head must have the same size group. Therefore, before assembling the “piston - pin - connecting rod” kit, you must make sure that the markings applied with paint on one of the piston bosses, on the ends of the pin and the upper head of the connecting rod are made with the same paint.

In the case when the entire cylinder-piston group is changed, which most often happens in practice, there are no problems with the selection: the piston, pin, piston rings and sleeve supplied to the spare parts as a set are selected in advance. Therefore, during assembly, it is required to make sure that the selection is correct by marking the parts and check the gap between the piston and the sleeve with a feeler tape. You can do without a probe tape. A properly selected piston should, under its own weight, slowly lower in the sleeve. It is also necessary to check whether the new piston pin fits the connecting rod upper head: the piston pin should smoothly enter the hole in the connecting rod upper head bushing under the pressure of the thumb.

Before connecting the piston to the connecting rod, the latter must be checked for parallelism of the axes-heads. This is done on a control device with indicator heads.

When the deformation exceeds the allowable limits, the connecting rod is corrected. Then the piston is placed in a bath of liquid oil, heated to a temperature of 60 ° C and, using a mandrel, the piston pin is pressed into the holes of the piston bosses and the upper head of the connecting rod. After pressing, retaining rings are inserted into the grooves of the bosses.

Similarly, starting with the removal of the cylinder head in the sump, they proceed if it is necessary to replace the bushing of the upper head of the connecting rod, piston pin and piston rings. Unusable bushings are pressed in, and new ones are pressed in their place, while providing the necessary clearance. Then the bushings are bored on a horizontal boring machine or processed using a reamer. The inner surface of the bushing must be clean, without scratches with a roughness parameter of the order of Ro = 0.63 μm, and the ovality and taper of the hole should not exceed 0.004 mm.

Before installing the piston assembly with the connecting rod in the cylinder block, a set of piston rings is installed in the piston grooves. In addition, the rings are checked for clearance, for which they are inserted into the upper unworn part of the cylinder liner and visually assess the fit.

The gap in the lock is determined with a feeler gauge and, if it is less than the permissible value, the ends of the rings are cut off. After that, the ring is re-checked for clearance and only then, using a special device that unclenches the ring by the ends in the lock, is it installed in the grooves of the pistons.

Sets of rings of nominal size are used for TR engines, the cylinders of which have not been bored, and rings of repair size are installed in the bored ones, which, in terms of outer diameter, correspond to the new diameter of the cylinders.

The joints (locks) of adjacent rings are evenly spaced around the circumference. Compression rings on the piston are installed with a chamfer up. At the same time, they must rotate freely in the piston grooves. Installation of pistons complete with rings in the engine cylinders is carried out using a special tool.

The replacement of the crankshaft liners is carried out when the bearings knock and the pressure in the oil line drops below 0.5 kgf / cm2 at a crankshaft speed of 500-600 rpm and the oil pump and pressure reducing valves work properly. The need to replace the liners is due to the diametrical clearance in the main and connecting rod bearings: if it is more than acceptable, the liners are replaced with new ones. The nominal clearance between the liners and the main journal should be 0.026-0.12 mm, between the liners and the connecting rod journal 0.026-0.11 mm, depending on the engine model.

The clearance in the crankshaft bearings is determined using control brass plates. For ZIL and GAZ car engines, copper foil plates with a thickness of 0.025 are used; 0.05; 0.075 mm, 6-7 mm wide and 5 mm shorter than the insert width. An oil-lubricated plate is placed between the shaft neck and the liner (Fig. 9.9), and the bearing cover bolts are tightened with a torque wrench with a torque specific for each engine (for main bearings of the ZIL-130 engine, this is 110-130 N m, connecting rod 70-80 N m). If the crankshaft rotates too easily when installing a plate with a thickness of 0.025 mm, then the gap is greater than 0.025 mm and, therefore, the plate should be replaced with the next size until the shaft rotates with a noticeable effort, which corresponds to the actual gap between the neck and the liner. When checking one bearing, the bolts of the others must be loosened. So all bearings are checked one by one.

It is necessary that there are no burrs on the surface of the crankshaft journals. In the presence of scoring and wear, it is not advisable to replace the liners. In this case, the crankshaft needs to be replaced.

After checking the condition of the crankshaft journals, the liners of the required size are washed, wiped and installed in the bed of the main and connecting rod bearings, having previously lubricated the surface of the liner and neck with engine oil.

For ZIL-130 engines, in addition to the nominal, there are five repair sizes of the main and connecting rod journals of the crankshaft. Accordingly, six sets of liners are produced: nominal, 1, 2, 3, 4, 5 repair sizes.

The adjustment of the axial play of the crankshaft for the ZIL-130 and ZMZ-53 engines is carried out by selecting thrust washers. For ZMZ-53 engines, the axial clearance between the front thrust end of the crankshaft and the rear thrust washer should be 0.075-0.175 mm, and for ZIL-130 engines 0.075-0.245 mm.

During operation, due to wear, the axial clearance increases. When TR, it is regulated by installing thrust washers or half rings of repair sizes, which, in comparison with the nominal size, have an increased (by 0.1; 0.2; 0.3 mm, respectively) thickness.

The main malfunctions of the block heads are: cracks on the mating surface with the cylinder block, cracks on the cooling jacket, warping of the mating surface with the cylinder block, wear of the holes in the valve guide bushings, wear and shells on the chamfers of the valve seats, weakening of the fit of the valve seats in the sockets.

Cracks no longer than 150 mm located on the mating surface of the cylinder head with the block are welded. Before welding, at the ends of the cracks in the head made of aluminum alloy, holes Ø 4 mm are drilled and it is cut along its entire length to a depth of 3 mm at an angle of 90 °. Then the head is heated in an electric furnace to 200 ° C and after cleaning the seam with a metal brush, the crack is welded with an even seam direct current reverse polarity using special electrodes.

When welding with a gas method, a burner with a tip No. 4 and a wire of the AL4 brand with a diameter of 6 mm are used, and AF-4A is used as a flux. After welding, the flux residues are removed from the seam and washed with a 10% solution of nitric acid, and then with hot water. After that, the seam is cleaned flush with the base metal with a grinding wheel.

Cracks up to 150 mm long, located on the surface of the cylinder head cooling jacket, are sealed with epoxy paste. The crack is preliminarily cut in the same way as for welding, degreased with acetone, two layers of epoxy composition mixed with aluminum filings are applied. Then the head is kept for 48 hours at 18-20 °C.

The warping of the mating plane of the head with the cylinder block is eliminated by grinding or milling "as cleanly". After processing, the heads are checked on a control plate. A probe 0.15 mm thick must not pass between the plane of the head and the plate.

If the holes in the valve guides are worn out, replace them with new ones. The holes of the new bushings are unrolled to the nominal or repair dimensions. For pressing and pressing the guides, a mandrel and a hydraulic press are used.

Wear and shells on the chamfers of valve seats are eliminated by lapping or grinding. Grinding is performed using a pneumatic drill, on the spindle of which a suction cup is installed.

For lapping valves, lapping paste (15 g of M20 or M12 white electrocorundum micropowder, 15 g of M40 boron carbide and M10G2 or M10V2 engine oil) or GOI paste is used. The ground-in valve and seat must have a smooth matte strip of 1.5 mm along the entire circumference of the chamfer.

The quality of grinding is also checked by a device that creates excess air pressure above the valve. After reaching a pressure of 0.07 MPa, it should not noticeably decrease within 1 min.

In the case when it is not possible to restore the chamfers of the seats by grinding, the seats are countersinked, followed by grinding and grinding. After countersinking, the working chamfers of the valve seats are ground with abrasive wheels at an appropriate angle, and then the valves are ground. If there are shells on the chamfer and when the seat is loosened in the seat of the block head, it is pressed in with a puller, and the hole is bored under the repair size saddle. Made from high strength cast iron. saddles of the repair size are pressed with a special mandrel into the preheated head of the block, and then the chamfer of the saddle is formed with countersinks.

Typical malfunctions valves are wear and tear on the chamfer of the valve, wear and deformation of the valve stems, wear of the valve face. When the valves are faulty, the straightness of the rod and the beating of the working chamfer of the head relative to the rod are checked. If the runout is more than acceptable, the valve is corrected. When the valve stem is worn, it is ground to one of the two repair sizes provided for by the specifications on a centerless grinding machine. The worn end of the valve stem is ground “as clean” on a grinding machine.

For grinding a worn chamfer, a model P108 machine is used. On it, the cylindrical surface of worn pushers is ground to one of the two repair sizes provided for by the specifications, worn spherical surfaces of pushers and rocker arms.

At large ATPs and in motor transport associations that have specialized sections for the restoration of parts, they carry out repairs of crankshafts and camshafts. Worn main and connecting rod journals of the crankshafts, as well as the bearing journals of the camshafts, are ground to repair dimensions on a circular grinding machine. After grinding, the necks of the crankshaft and camshaft are polished with an abrasive tape or GOI paste. Worn camshaft cams are ground on a copy-grinding machine.

Cooling system. External signs of a malfunction of the cooling system are overheating or excessive cooling of the engine, loss of tightness. Overheating is possible with a lack of coolant in the system. This is especially evident when using antifreezes, which foam due to the presence of air in the system and slow down the removal of heat. To prevent freezing of antifreeze, it is necessary to maintain its standard density. So, at 20 ° C, the density of antifreeze A-40 should be 1.067-1.072 g / cm3, and antifreeze Tosol A-40 1.075-1.085 g / cm3

The efficiency of the cooling system also decreases when the fan belt is loosened. The tension of the ZMZ-53 engine belt is regulated by changing the position tension roller. With a force of 30-40 N, the belt deflection should be 10-15 mm. The KamAZ-740 engine is adjusted by changing the position of the generator. With a force of 40 N, the belt deflection should be 15-22 mm.

A faulty thermostat can also cause the cooling system to malfunction. Liquid thermostats trucks in case of loss of tightness, they are filled with a 15% solution of ethyl alcohol and sealed with soft solder.

On the cars modern designs, as a rule, powder (fraction of ceresin mixed with aluminum powder) thermostats are installed. If they fail, they are replaced with new ones. Check thermostats in hot water. For a powder thermostat, for example, an AZLK-2141 car, the temperature at which the valve starts to open is 815°C. For the beginning of the opening of the valve, its movement of 0.1 mm is read. The thermostat must be fully open at 94°C (valve travel at least 6 mm).

Radiator malfunctions mainly include scale formation and loss of tightness.

Under ATP conditions, scale is removed for engines with a cast-iron head with a solution of caustic (700-1000 g of caustic and 150 g of kerosene per 10 liters of water), for engines with a head and an aluminum alloy block - with a solution of chromium peak or chromic anhydride (200 g per 10 liters of water ) The solution is poured into the cooling system for 7-10 hours, then the engine is started for 15-20 minutes (at low speed) and the solution is drained. To remove sludge, the system is flushed with water in the direction opposite to the circulation of the coolant.

The tightness is restored by soldering the damaged areas. Heavily damaged tubes are replaced with new ones or removed (muffled), the installation sites are soldered. It is allowed to muffle no more than 5% of the tubes and install new ones no more than 20%.

Soldering radiators made of brass alloys does not cause difficulties. It is more difficult to repair radiators made of aluminum alloys. To do this, use gas burners, filler material - wire SVAK5 with a diameter of 3-4 mm, bar solder brand 34A, powdered flux F-34A. The place prepared for soldering is heated with a burner flame to 400-560 ° C. If the part is not heated enough, then the solder will not be evenly distributed over the surface, but will be collected in separate flows. The heating temperature of the soldering zone in practice can be determined with good accuracy with a wooden stick. When in contact with a normally heated surface, the stick chars and leaves a dark mark.

Before installation on a car, the tightness of the radiator is tested with compressed air at a pressure of 0.1 MPa for 3-5 minutes. When tested with water, the pressure should be 0.1-0.15 MPa.

Lubrication system. External signs of a system malfunction are loss of tightness, oil contamination and discrepancy between the pressure in the system and the standard values: for GAZ-53A, ZIL-130 vehicles at a speed of 40-50 km / h in direct gear, the pressure in the system should be 0.2-0.4 MPa. When the idle pressure drops to 0.09-0.04 MPa for the GAZ-53A and 0.06-0.03 MPa for the ZIL-130, the warning light on the instrument panel lights up. In a warmed-up KamAZ-740 engine at 2600 rpm of the crankshaft, the pressure should be 0.45-0.5 MPa,

Automobile oil pressure gauges can have a significant error, so periodically their readings must be compared with the readings of a mechanical pressure gauge installed in place of the oil sensor.

During operation, sediments accumulate in the lubrication system, consisting of products of incomplete combustion of fuel and oil oxidation. Oil additives also contribute to deposits. New oils poured during maintenance have detergent properties and partially wash out deposits, thereby contaminating the oil. Prolonged idling of the engine low temperatures water and oil contributes to intensive sedimentation. Subsequent operation of the engine at high loads and temperatures causing soft deposits to harden. Sedimentation causes clogging of the oil line, scoring of liners, occurrence of rings, etc.

Removing deposits, i.e. flushing the lubrication system, is a necessary technological operation, especially when the engine is seasonally switched to another brand of oil. Flushing slows down the deterioration of physical and chemical parameters engine oil, increases engine compression (with a run of more than 100 thousand km) due to a freer position of the rings on the piston, reduces fuel consumption and oil waste, ensures better functioning of the lubrication system.

The system is flushed with oil-viscous oils (6-8 mm2/^) with special additives. In the USSR, this oil is VNIINP-113/3; the firm "FIAT" recommends flushing oil "Oliofiat L-20"; Shell manufactures Shell Donax oil.

The sequence for flushing the system is as follows:

Drain the used oil when the engine is hot;

Pour flushing oil up to the lower mark on the dipstick;

Start the engine (avoiding sudden accelerations) and let it run for about 20 minutes at a low speed;

Drain flushing oil;

Clean and wash the filters with kerosene, replace their elements;

Fill in fresh oil, start the engine and let it run at a low frequency so that the oil fills the entire system;

Check the oil level and top up if necessary.

Flushing oil after settling can still be used 1-2 times.

With absence washing oils, as an exception, you can use summer diesel fuel. Washing time in this case is not more than 5 minutes.

Reduced pressure in the system is the result insufficient level oil, oil dilution or the use of low viscosity oil, clogging of the oil intake screen, filters, wear of a number of parts, sticking of the pressure reducing or bypass valves in the open position. On KamAZ vehicles, when the bypass valve is opened, the signal lamp lights up.

Increased pressure is the result of using oil with a higher viscosity, such as summer oil. winter period, jamming pressure reducing valve in the closed state.

The reliability of the lubrication system largely depends on the condition of the filters. Majority modern engines has two filters: full-flow (coarse) and centrifugal (fine).

At TO-2, full-flow filters are replaced with filter elements, and centrifugal ones are disassembled, inspected and washed.

Under normal operating conditions, when the centrifuge is working properly, after 10-12 thousand km of run, 150-200 g of deposits accumulate in the rotor cap, difficult conditions- up to 600 g (4 mm of sediment layer thickness corresponds to approx. 100 g). The absence of deposits indicates that the rotor has not rotated and the dirt has been washed away by the circulating oil. On a ZIL-130 car, this may be due to a strong tightening of the casing wing nut, on KamAZ vehicles as a result of spontaneous unscrewing of the rotor fastening nut.

The frequency of oil change is determined depending on the brand of oil and car model. The oil level is checked 2-3 minutes after the engine is stopped. It should be between the marks on the dipstick.

Supply system gasoline engines. Although the power system accounts for no more than 5% of failures and obvious malfunctions in the car, the condition of its main element, the carburetor, is decisive for ensuring fuel efficiency (according to the latest data, the average excessive fuel consumption due to faults not identified by external signs is 10-15% ) and the permissible concentration of harmful components in the exhaust gases. Obvious malfunctions include leakage and leakage of fuel from fuel tanks and fuel lines, engine “failures” during sudden opening throttle valve due to deterioration in the functioning of the accelerator pump; to implicit - pollution (increase in hydraulic resistance) air filters, breakage of the diaphragm and leakage of the fuel pump valves, violation of the tightness of the needle valve and a change in the fuel level in the float chamber, a change (increase) in the throughput of the jets, incorrect idle speed adjustment.

Identification of implicit malfunctions of the carburetor and gasoline pump is carried out by running and bench tests, as well as by assessing the condition of individual elements after removing the carburetor and its preventive overhaul and testing in workshop conditions.

In road tests, which are recommended to be carried out with the car moving at a constant speed on a measured horizontal section of the highway, or based on careful consideration of fuel consumption during normal operation, the economy is evaluated using various flow meters. Exceeding the efficiency standard (with a good ignition) here indicates a time adjustment of the main dosing system. It is more convenient to carry out such tests covering all ranges of carburetor operation (turning on the second chamber and economizer) on a bench with running drums (see Section 9.6). In this case, it is also possible to obtain information on the degree of discrepancy between the throughput of the jets of the main dosing system and economical modes.

A sign of "economy" is the stable operation of the carburetor in constant and variable load modes only when the engine and carburetor are fully warmed up. If stable operation is already observed on a cold or slightly warmed-up engine, then this indicates an unacceptable over-enrichment of the mixture. The leakage of the needle valve of the float chamber also leads to the re-enrichment of the mixture. A symptom of the latter is, as a rule, difficult “starting” of the engine due to overflow of the float chamber. In the absence of inspection windows or control plugs, overfilling can be detected visually by fuel leakage into the diffuser after the engine is stopped, for which it is necessary to first dismantle the air filter.

In the conditions of the workshop at the carburetor, in addition to the tightness of the needle valve and the fuel level in the float chamber, they also check the throughput of the jets and the tightness of the economizer valve. At gasoline pumps, they check the created vacuum (not lower than 50 kPa), pressure (17-30 kPa) and performance (0.7-2.0 l / min), as well as the presence of damage to the diaphragm. These types of tests can be carried out both on separate fixtures and devices, and on special combined stands (of the type "Carbutest-standard" manufactured by VNR).

The most important is to check the throughput of the jets, measured in the amount of water in cubic centimeters, flowing through the metering hole of the jet in 1 min under a pressure of a water column of 1m ± 2 mm at a temperature of (20l) °C. Based on these measurements, it is possible not only to check the compliance of the jets with passport data, but also to carry out an individual “adjustment” of the throughput fuel jets the main dosing system for each carburetor to ensure economical modes of operation (based on data from the diagnostic site or tests of the carburetor on "non-motorized installations). For carburetors with a vacuum drive of the economizer, the pressure resistance of its opening and closing is also checked, which should be 13 and 16 kPa, respectively.

Recently, direct tests of the car engine for efficiency at the diagnostic site have become increasingly important, on the basis of which it is also possible to obtain quantitative data on the change in the throughput of the jets of the main metering system.

Diesel power system. The power system accounts for up to 9% of faults in vehicles with diesel engines. Typical faults are:

leakage and leakage of fuel, especially high-pressure fuel lines; air pollution and especially fuel filters; oil getting into the blower; wear and misalignment of plunger pairs of the high pressure pump; loss of tightness of the nozzles and a decrease in the pressure of the beginning of the lifting of the needle; wear of nozzle outlets, their coking and clogging. These malfunctions lead to a change in the moment of the start of fuel supply and injection, uneven operation of the fuel pump in terms of the angle and amount of fuel supplied, deterioration in the quality of sawing fuel, which primarily causes an increase in the smoke of exhaust gases and, to a small extent, leads to an increase in fuel consumption and a decrease in engine power ( by 3-5%).

Control of the power system includes: checking the tightness of the system and the condition of the fuel and air filters, checking the fuel priming pump, as well as the high pressure pump and injectors.

Lack of tightness of the part of the system under high pressure is checked visually by fuel leakage with the engine running. Lack of tightness of the inlet part (from the tank to the fuel priming pump), leading to air leakage and disruption of the fuel priming equipment, is checked using a special tank device. A part of the line under low pressure can be checked for leaks and when idle engine by pressing with a manual fuel priming pump. Condition of dry air filters installed on all latest models cars, check the negative pressure behind the filter using a water piezometer (should be no more than 700 mm of water column).

The control of the high-pressure pump and injectors directly on the vehicle is carried out when the engine exceeds the norms for smoke and in order to identify malfunctions and optimize technical interventions for the maintenance and repair of fuel equipment. The most widely used method is based on the analysis of pressure changes, recorded using a special sensor installed at the nozzle in the break of the delivery fuel line. Diagnostics according to this method is carried out using simplified analog devices with one built-in sensor and a stroboscope (type K261), which provide determination of the engine crankshaft speed, the fuel injection advance setting angle, the possibility of checking the quality of the speed controller and the automatic fuel injection advance clutch, and also injection start pressure and maximum pressure injection for each cylinder (when the sensor is moved). Diesel testers with an oscilloscope and simultaneous installation of sensors on all injectors are less common due to the difficulties of installing and removing sensors.

In the absence of diagnostic tools to reduce smoke, it is necessary to carry out labor-intensive preventive work, primarily on nozzles and a high-pressure pump with their removal and subsequent reassembly and testing in the workshop. The removed nozzle is checked for tightness at a pressure of 30 MPa, while the pressure drop time from 28 to 23 MPa must be at least 8 s; at the beginning of the rise (injection pressure), which should be (! 6.5 4-0.5) MPa for KamAZ engines, (14.7 + 0.5) MPa and for YaMZ engines; on the quality of the spray, which should be clear, misty and even in cross section cone, have a characteristic "metallic" sound. The injection pressure of the nozzle is adjusted by changing the thickness of the shims installed under the spring, or by using the adjusting nut.

The most complex and responsible are the workshop check and adjustment of the high-pressure pump at the beginning of the supply, its uniformity and the actual fuel supply, carried out on special stands. The inaccuracy of the interval between the beginning of the fuel supply by each section relative to the first should not exceed: fc20 ", and the unevenness when the rail is set to the maximum supply position - no more than 5% fuel when the engine is stopped, automatic shutdown of the fuel supply at the set maximum engine crankshaft speed and automatic governor start frequency).

The high-pressure pump is mounted on the engines using a momentoscope - a glass tube with an inner diameter of 1.5 - 2.0 mm, installed on the outlet fitting of the 1st or previous section of the pump in the order of operation, upon the appearance of fuel in which the drive coupling is fixed in such a way so that the lead angle is 16-19 ° to TDC of the 1st cylinder. The performance of these works provides (with correct adjustment valves and good compression in the engine cylinders) minimum smoke and maximum efficiency of the diesel engine in a hot state

1.2.3 a brief description of lines (zones), maintenance departments (TR)

According to design standards, workshops for the repair of units, engines and a mechanical fitter can be located in one room. However, in practice there is a tendency to locate them in separate rooms. In addition, for the normal functioning of the assembly shop and the engine repair shop, a separately located washing or washing-dismantling section is provided. Engines and units, as the heaviest repair objects, as well as close technological connection between the current repair zone, predetermine the location of these workshops as close as possible to the posts of the TR zone.

Work on TR is carried out according to the need, which is revealed as a result of monitoring the operation of the vehicle on the line, in the process of control and diagnostic work and during maintenance.

There are two methods of TR: aggregate and individual. The most promising is the aggregate method. it allows you to reduce the downtime of the car and makes it possible to organize the repair of mechanisms, components and engines outside the car repair shop - at specialized repair shops. However, it should be taken into account that with this method of TR it is necessary to have an irreducible fund of circulating units that satisfy the daily need of a car repair enterprise.

The engine repair site is located directly in the production complex, next to other departments, areas, lines for maintenance and repair of vehicles. It has an area of ​​72 square meters, including an area for washing units, engines. It is divided into two zones: washing and assembly (repair).

Work on the site is carried out by highly qualified workers: two minders of the 5th and 4th category, respectively, and when the site is busy, an auxiliary locksmith of the 3rd category is involved.

The site has a sufficient number of windows, thus well lit by daylight.

All engines requiring repair enter the repair zone, where they are being repaired, through the washing zone of the site. The repaired engines are delivered to the running-in stand, after which they are transferred to the MOT and TR zone, where they are installed on the car.

1.2.4 Analysis of the positive aspects and disadvantages of the line, zone,

site

TO positive side of the designed site for the repair of engines, it should be attributed to its sufficiently complete provision with mechanized equipment, which leads to a decrease in the labor intensity of work and physical stress on repair workers.

Rational organization of TR technology, mechanization of manual labor contributes to an increase in labor productivity, which ultimately affects the general technical condition of the fleet and the economic performance of the car repair enterprise as a whole

The disadvantages of the designed site include the need to use highly skilled workers with higher wages to be able to perform all types of work at the proper level with a relatively small production program TR

1.2.5 Organization of quality control of engine repair

Quality control of maintenance and repair is part of the production process. The ultimate goal of which, ultimately, is to prevent marriage and improve the quality of work performed. Objective indicators of the quality of work are the duration of the vehicle's uptime on the line after maintenance and repair.

The main functions of quality control of maintenance and repair of rolling stock are assigned to the technical control department (TCD). QCD specialists at most enterprises focus on checking the technical condition of the vehicle when it is released onto the line and returned to the enterprise, as well as quality control of work performed directly on the vehicle.

After the completion of TO-1, TO-2 and TR, not only the quality of work is controlled, but also the implementation of the accepted list of operations. Control is carried out visually using portable devices, as well as using the available equipment for diagnostics. The use of diagnostic tools allows you to objectively assess the quality of the work performed and the readiness of the vehicle for production on the line at a minimum cost of time.

Every assembled engine run in and tested on the stand. First, the engine undergoes a cold run-in with forced rotation of the crankshaft from the electric drive for 20 minutes. Then hot running in without load for 20 minutes and hot running in under load for 25 minutes.

During hot break-in, a temperature regime of 75 - 90 0 С is maintained, oil pressure is controlled, which should be at least 2.5 kgf / cm 2 at 1000 rpm of the crankshaft. During the running-in process, a uniform noise of distribution gears, a slight knock of valves and pushers, as well as the formation of oily spots and individual seals and joints of parts with a fall of no more than 1 drop in 5 minutes are allowed.

An engine is considered accepted if it meets the following requirements:

It starts from the starter with two or three revolutions of the crankshaft;

After warming up, it works steadily without overheating and interruptions at low and medium speeds

Does not stop and does not give interruptions when switching from high to low speeds and vice versa

All cylinders work evenly at all loads and speeds

The oil addition is within the specified limits.

1.3 Organizational and technological part

1.3.1 Calculation of the listed car park

The calculation of the listed car park is allocated according to the formula:

The total labor intensity of the car park for this type of service

Average labor intensity of the fleet for this type of service

Table 1: Standards for the labor intensity of maintenance and current repairs of rolling stock

For TO-2 will be:

The total labor intensity of the car park at TO-1

Average labor intensity of the fleet at TO-1

K2 - Modification of the rolling stock and features of the organization of its work (cars with trailers, dump trucks, etc.), which is used to adjust the labor intensity of maintenance and repair, mileage to overhaul, consumption of spare parts. (I accept K2 = 1.00)

K3 - Natural and climatic conditions are taken into account when determining the frequency of maintenance, the specific labor intensity of TR and the norms of mileage to the capital, which change accordingly: taking into account the aggressiveness of the environment when determining the frequency; specific labor intensity of TR; when determining resources before the first overhaul, respectively; spare parts consumption.

K4 - takes into account the change in the labor intensity of the TR of cars in repair, depending on the mileage of the car from the beginning of operation - age. (I accept K4 = 1.00)

K5 - takes into account the level of rolling stock concentration, i.e. the size of the vehicle and production associations, as well as the diversity of parks. The latter is taken into account by the number of technologically compatible, i.e. requiring the same maintenance facilities (posts, equipment) in the park (at least 25 in a group). (I accept K4 = 1.15)

Table 2: Correction factor for standards depending on operating conditions - K1

table 2

Table 3: Coefficient of adjustment of standards depending on the modification of the rolling stock and the organization of its work - K2

Table 3

Table 4: Coefficient of adjustment of standards depending on natural and climatic conditions - K3

Table 4

Table 5: Correction coefficients for the norms of the specific labor intensity of the current repair K4 and the downtime in maintenance and repair K4’, depending on the mileage since the start of operation

Table 5

1.3.2 Calculation of the production program for MOT and TR

Calculation of the number of TO and TR

Determining the frequency of maintenance and repair

The norms of mileage to overhaul (KR) and the frequency of maintenance are determined on the basis of the current Regulations.

mileage to TO-1 L 1 \u003d 3000 km

mileage to TO-2 L 2 \u003d 12000 km

mileage to KR L kr \u003d 300,000 km

The standards for the frequency of maintenance and repair should be adjusted using the coefficients:

k 1 \u003d 0.8 - coefficient taking into account the category of operating conditions;

k 2 \u003d 1 - coefficient taking into account the type of rolling stock;

k 3 \u003d 0.81 - coefficient taking into account natural and climatic conditions;

Since the car is put into service taking into account the average daily mileage after an integer number of working days, the mileage to maintenance and repair must be a multiple of the average daily mileage and among themselves. The correction data for these indicators, the normative and obtained values ​​are summarized in the table.

Table 6: Adjustment of mileage to TO-1, TO-2 and KR

Table 6

Determining the number of maintenance and repair work per car per cycle

In accordance with the accepted notation, the calculation of the amount of repair and maintenance is presented as:

Capital repairs for the CEC

;

Number of TO-2 per cycle

;

Number of TO-1 per cycle

Number of EOs per cycle

;

Determining the number of maintenance and repair work per year

Since the mileage of a car per cycle can be more or less than the mileage per year, and the production program of the enterprise is usually calculated for a year period, it is necessary to make an appropriate recalculation. To do this, we first determine the coefficient of technical readiness, knowing which it is possible to calculate the annual mileage of the car (park) and, as a result, determine the annual program for maintenance and repair of the car. The coefficient of technical readiness is expressed by the following formula:

,

where D ets - the number of days of operation of the car (park) per cycle D ets =

D rc - the number of days the car (park) is idle for repairs and maintenance-2 per cycle.

The number of days of vehicle operation per cycle is determined from the expression:

Since the duration of vehicle downtime in TO and TR in the Regulation is provided in the form of a total specific gravity per 1000 km, the number of days of vehicle downtime per cycle D rc can be expressed as follows:

,

where Dstr is the specific downtime of the car in maintenance and repair per 1000 km of run;

Days of idle car in the Kyrgyz Republic (22 days, position)

Days of idle maintenance and TR (Take 0.5 days per 1000 km, position)

The number of days the park is open per year (working calendar 2008)

Number of calendar days in a year

Based on the calculated value of the coefficients of technical readiness, the annual mileage of the car is determined

Based on the known values ​​​​of the annual and cycle mileage of the car, the transition coefficient from cycle to year is determined:

;

The number of maintenance and repairs for the entire fleet per year is:

Number of CRs per year for the entire fleet of vehicles

The number of TO-2 per year for the entire fleet of vehicles

Number of TO-1 per year for the entire vehicle fleet

The number of SWs per year for the entire fleet of vehicles

where , etc. total values ​​of the number of technical maintenance and repairs of one-brand cars in the fleet.

The daily program of the park for maintenance and repair

The daily program of the fleet for maintenance and repair is determined from the expression:

where N i .G- daily number of maintenance and repairs for each type separately;

The annual number of maintenance and repairs for each type separately;

D rg - the number of working days per year performing work in the TO TR zone.

Number of CRs per day for the entire fleet of vehicles

;

The number of TO-2 per day for the entire fleet of vehicles

;

The number of TO-1 per day for the entire fleet of vehicles

;

The number of EOs per day for the entire fleet of vehicles

;

Determination of the annual labor intensity of maintenance and repair work per year with the presence of diagnostic posts at the ATP

The annual labor intensity of rolling stock maintenance is determined by the general formula:

where N i .g - the annual number of services of this type;

K 1, K 2, K 3, K 4, K 5 - coefficients (Tables 2-5)

Estimated labor intensity of a unit of maintenance of this type. (Table 1)

; for EO, ​​TO-1, TO-2

; for TR./1000 km

Table 7: Adjusted coefficients

Table 7

Total labor input EO

The total complexity of TO-1

The total complexity of TO-2

The standards of labor intensity of CO are from the labor intensity of TO-2 70%

Annual labor intensity of TR for the park:

where is the annual mileage of the car park, km

t TR- estimated labor intensity of TR per 1000 km, man-hour.

the annual mileage of the car fleet is determined by the following formula:

We determine the estimated labor intensity of TR per 1000 km, person h.

Table 8 Distribution of labor intensity by types of work

Table 8

Table 9: Approximate distribution of TR labor intensity by type of work

1.3.3. Calculation of the state for the performance of work

The technologically necessary number of workers is determined by the formula:

where T I- the annual volume of work (labor intensity) of the corresponding zone of maintenance, TR, workshop, separate specialized post or diagnostic line, man-hour;

F M. - annual productive fund of workplace time (handbook, 2070, for ATP)

For TO-1:

For TO-2:

For TR:

F R - the annual fund of time of a full-time worker (with a forty-hour week of 1993 hours, according to the working calendar of 2008)

For TO-1:

For TO-2:

For TR:

1.3.4. Calculation of the number of maintenance and repair posts

I define the rhythm of production R:

For TO-1

For TO-2

T PR - The duration of the zone per day

N TO - the number of TO-1, TO-2 services (per day)

The production cycle is determined

where t I- adjusted labor intensity of this type of maintenance unit (Table 7)

Pti– Number of full-time workers simultaneously working at the post

t pm – the time of moving the car from post to post.

I determine the number of posts TO-1, TO-2:

Coefficient taking into account the performance of additional non-labor-intensive work at the post (apply 0.9, guidelines)

The total number of posts in the TR zone will be:

where T TRP- annual labor intensity of guard work (Table 9); - the coefficient of use of the working time of the post. - coefficient taking into account the uneven arrival of cars on the maintenance zones; K TR - The share of the volume of work performed at the posts of the TR on the busiest shift D WG - the number of working days per year

R SR- the average number of workers at the post; FROM- number of shifts;

T SM- Length of work shift

1.3.5. Table and description of selected equipment

The amount of equipment required is calculated by the formula:

Annual labor intensity for this type of maintenance or repair

Number of working days per year

Work shift duration

Number of working shifts

Number of workers simultaneously working on this equipment (1 person)

Equipment utilization factor (accept 0.8, guidelines)

Table 10: Selected equipment

1.3.6 Determining the area of ​​posts sections

The TO area will be:

where Fa- the area occupied by the car in the plan;

P- number of posts;

K PA= 5 - density factor for the arrangement of posts and equipment;

D- the length of the car (For calculation, I take the length of the KamAZ vehicle, since it is longer than the length of the URAL vehicle, the width is the same;

W- car width.

For zones TO-1 and TO-2, the area will be 98.5 m 2 each

The area of ​​two posts TR = 197 m 2

Total area of ​​maintenance and repair posts: 394 m 2

1.3.7 Description of the layout of the engine repair area

The engine repair area is located directly on the production complex, next to other departments, maintenance and vehicle repair areas.

The engine repair area has a production area of ​​72 square meters. The site is divided into two industrial premises interconnected by doors. Washing takes place in one room not separated from the maintenance and repair zones, and after repair and running-in of engines, there are installed washing plant, running-in stand, racks for parts. Engines are being repaired in another closed room. It contains the equipment shown in (Table 10).

The building uses a grid of columns 6*12. At the site, crane-beams are installed in the first and second rooms to move heavy spare parts, and the engine itself as a whole.

1.3.8 Organization of maintenance and repair on the site

Scheme of the technological process T.O. and car repair

When returning from whether the car passes through the checkpoint (KTP), where the mechanic on duty spends visual inspection car (road train) and, if necessary, makes an application for TR in the prescribed form. The car is then serviced daily. (EO) and, depending on the schedule of preventive maintenance, it enters the posts of general or element-by-element diagnostics (D-1 or D-2) through the maintenance and current repair waiting area or to the car storage area. After -1, the car enters the TO-1 zone, and after those m in the storage area. Cars are sent there after D-2. If at D-1 it is not possible to detect a malfunction, then the car is directed to D-2 through the waiting area. After eliminating the detected malfunction, the car enters the TO1 zone, and from there to the storage zone.

Cars that have passed D-2 diagnostics 1-2 days in advance are sent to the TO-2 zone for scheduled maintenance and troubleshooting indicated in the diagnostic card, and from there to the storage area.

1.4 Determining the energy needs of the site

1.4.1 Lighting

Glazing area:

Glazing area

Floor area

0.25 - light factor

Z– Number of window openings theoretically required

Area of ​​window openings

In fact, there are 3 windows in the workshop with an area of ​​9 m 2

artificial lighting. At night, the engine compartment is illuminated with 2 fluorescent lamps. in a lamp with a power of 90 W each.

Calculate the required number of lamps:

W - Specific power W / m 2 (take 15 - 20)

P - Power of one lamp, W

n - The number of lamps in the lamp, pcs.

,PCS.

From here I determine total power for electric lighting

, kWh;

n– number of lamps, pcs.

K c - demand coefficient (0.6 -0.8)

T s - the annual number of hours of use of fixtures (take 2100 hours, Guidelines)

1.4.2 Heating

Due to the complexity of the calculation, to facilitate heating, I calculate based on the consumption of reference fuel:

kg;

q - Reference fuel consumption per 1 m 2 of the building per year (take 0.15 - 0.25 kg / m 3, guidelines)

V n - the volume of the room, m 3

t in - the temperature required indoors (10 0 C);

t n - external average t 0 air (-32 0 C)

h = 6 m - height with ceiling

, m 3

Substitute the results obtained into the formula

Let's convert from kilograms to tons for convenience in further calculations.

3110.4 / 1000 \u003d 3.11, t

1.4.3 Ventilation

The workshop uses supply and exhaust ventilation, as well as smoke exhausters.

Supply ventilation with VKR-5 fan, power 0.75 kW, rotation speed 920 rpm and capacity 720 m 3 /hour. Exhaust ventilation is used in the form of a hood with a V-Ts14-46-3.15 fan with a power of 1.1 kW, a rotation speed of 1500 rpm and a capacity of 900 m 3 /hour. Smoke exhausters remove exhaust gases from the running-in stand.

Ventilation performance:

TO- the multiplicity of air volume per hour (take 4)

V n- room volume, m 3

, m 3 / hour

To calculate the cost of ventilation, I use the power of the applied electric motors and their performance

I calculate the total power of ventilation engines, kW

1.4.4. Water supply

In the engine area is washing machine for washing units and assemblies with a water consumption of 250 l/h with a special detergent. Industrial wastewater is treated to remove the oils and other compounds it contains. In accordance with sanitary standards, I plan to build washbasins, showers and toilets based on the following standards: 1 tap for 10 people, 1 shower for 5 people, 1 toilet bowl for 20 people. In total, 3 wash basins are obtained. 5 showers, 2 toilets. Of these, I take into account 1 washbasin, 1 shower room, in accordance with the norms of SNiP, the water consumption per worker is 25 l / day, the water consumption per shower is 40 l

I calculate the total water consumption according to the formula

e 2 - water consumption per worker (25 l / day);

e 3 - water consumption per shower per hour (40 l)

e 4 - water consumption for washing per hour (250 l)

from 2 - number of washing hours per day (3 hours)

Number of washbasin operating hours per day (0.5 hour)

D rg - the number of days of work per year, d.

s - the number of hours of operation of the shower per day (0.5 hour)

i - Number of shower screens

Of the total water consumption for hot water supply 30%, for cold 70%

E x \u003d E * 70% \u003d 195625 * 70% \u003d 136937.5, l.

E g \u003d E * 30% \u003d 195625 * 30% \u003d 58687.5, l.

1.4.5 Electricity

, kWh

1.5 Occupational safety, fire prevention and security

nature

1.5.1 Safety

General security measures:

Individuals who have the appropriate qualifications, who have received an introductory briefing on labor protection at the workplace, and who have passed an electrical safety test, are allowed to work independently on car repairs. A locksmith who has not passed a timely re-instruction on labor protection and the corresponding annual knowledge test should not start work. When applying for a job, a locksmith must undergo a preliminary medical examination, and in the future - periodic medical examinations established by the Ministry of Health.

It is forbidden to use tools, fixtures, equipment, handling of which the locksmith is not trained.

The locksmith is obliged to comply with the internal labor regulations, as well as the fire safety rules approved by the enterprise. Smoking is allowed only in designated areas. It is prohibited to consume alcoholic beverages and narcotic substances before and (or) during work.

The mechanic must know that the most dangerous and harmful production factors affecting him in the process of performing work are:

Flammable liquids, vapors, gases

leaded gasoline

· Equipment, tools, fixtures.

Flammable liquids, their vapors, gas - in case of violation of fire safety rules in handling them, they can cause a fire and explosion. In addition, vapors and gases, getting into the respiratory organs, cause poisoning of the body.

Leaded gasoline - has a toxic effect on the body, when inhaling its vapors, contaminating the body, clothing, ingesting it with food and drinking water.

Equipment, tools, devices - if used incorrectly, can lead to injury

The mechanic must work in overalls and, if necessary, use other personal protective equipment.

In accordance with the Model Industry Standards for the free issue of overalls, footwear and other personal protective equipment to workers and employees, a locksmith is issued with: A viscose-lavsan suit, a vinyl chloride apron, rubber boots, vinyl chloride oversleeves, combined mittens. When working with leaded gasoline additionally: rubber apron, rubber gloves.

The locksmith should perform only the work entrusted to him by the immediate supervisor. During work, he must be attentive, not be distracted by extraneous matters and conversations.

The mechanic must inform his immediate supervisor about the observed violations of safety requirements at his workplace, as well as about malfunctions of equipment, devices, tools and personal protective equipment and not start work until the violations and malfunctions are eliminated.

The locksmith must be able to provide first aid to the victim in accordance with the instructions for providing first aid in case of an accident.

On each accident, which he was an eyewitness, the locksmith must immediately inform the administration of the enterprise, and provide the victim with first aid, call a doctor or help deliver the victim to a health center or the nearest medical facility

If the accident occurred to the locksmith himself, he should, if possible, contact the health center, report the incident to the administration of the enterprise or ask someone from those around him to do it.

Safety precautions before starting work

Prepare the necessary personal protective equipment for work. Put on and fill overalls, fasten the cuffs of the sleeves. Get a job assignment from your immediate supervisor. Do not perform work without receiving a task and at the request of drivers or other persons

Review and prepare your workplace, remove all unnecessary items without cluttering the aisles.

Check the condition of the floor in the workplace. If the floor is slippery or damp, request that it be mopped or sprinkled with sawdust, or do it yourself.

Check the availability and serviceability of tools, fixtures and equipment. Do not work with faulty tools and fixtures or on faulty equipment and not only perform troubleshooting yourself.

Check the availability of fire equipment at the site and, in the absence of such, inform your supervisor about it.

Turn on supply and exhaust ventilation and, if necessary, local ventilation

To prevent electric shock, power tools are grounded.

Safety measures during work

When starting work on the maintenance and repair of the vehicle, take measures to prevent spillage of fuel from the fuel tank, fuel lines and power system devices. Make sure that the supply and main valves are closed and that there is no gas under pressure in the gas pipelines

When repairing, take measures to prevent sparking by removing the terminals from the battery or disconnecting it with a special device.

Before dismantling, neutralize carburetors and gasoline pumps running on leaded gasoline, as well as their parts with kerosene.

Wash parts only in places designated for this purpose. Washing baths with kerosene should be closed with lids when finished.

To disassemble and repair in special workbenches or stands. Use only special devices.

Purge the valves, tubes and jets of the fuel equipment with air from a hose or a pump. It is forbidden to blow them out with your mouth. When blowing out parts with a jet of air, do not direct it at nearby working people or at yourself.

When checking the operation of the nozzles on the stand, do not put your hand to the sprayer.

Checking the reliability of starting the engine and adjusting the minimum idle speed should be carried out at special posts equipped with local exhaust gases if the posts are located in the maintenance room.

Before starting the engine, check if the car is braked parking brake and whether there are special stops (shoes) under the wheels, whether the lever on the gear shift (controller) is set to the neutral position.

For the safety of crossing the inspection ditches, as well as for working in front and behind the vehicle, use walkways, and for descending into the inspection ditch, use ladders specially installed for this purpose.

If leaded gasoline comes into contact with the skin, immediately wash the spilled skin area with kerosene, and then wash with warm water and soap. If leaded gasoline (drops or vapors) gets into the eyes, rinse them with warm water and immediately contact a health center or doctor.

If the overalls are doused with gasoline, we will contact our immediate supervisor to replace them.

Safety precautions in an emergency

Suspend work

Immediately inform the management of the car depot about the traumatic event that happened to him, or through his fault, as well as about any accident involving other employees of the enterprise, of which he was a witness.

Take part in the elimination of the consequences of the accident

Provide the victim with an accident, first aid, help deliver him to the first-aid post, if necessary, call medical workers to the scene.

Safety measures after work

Upon completion of the work, the locksmith must:

Turn off ventilation and equipment.

Tidy up the workplace, tools and fixtures, thoroughly clean the remnants of leaded gasoline with rags abundantly moistened with kerosene, and then wipe with a dry rag, and then remove their designated place.

It is forbidden to drain the remains of kerosene and other flammable liquids into the sewer.

Take off your overalls and put them in the designated place.

Timely hand over overalls and other personal protective equipment for dry cleaning (washing).

1.5.2 Fire prevention measures

In the repair zone it is prohibited:

Use open flames, portable forges, blowtorches, etc. In those rooms where flammable combustible liquids are used (gasoline, kerosene, etc.), also in rooms with flammable materials (woodworking, wallpaper, etc.);

Wash parts with gasoline and kerosene in unspecified places

Store flammable liquids in excess of the daily requirement

Park the car in the presence of cutting from the tank, as well as refuel the car

Store clean cleaning cloth with used

Use portable lamps without protective nets

Use crowbars when rolling barrels of fuel

Open the caps of barrels with flammable liquids by hitting metal objects (you should use a special key made of non-ferrous metal)

Block up the passages between the racks and exits from the premises with equipment, containers, etc.

Install cars in the zone in excess of the norm, or violate the way they are arranged

Block up emergency gates, both inside and out

For every 50 m 2 there should be one fire extinguisher, but not less than two for each room

Boxes with dry sand are installed in the premises at the rate of 0.5 m 3 per 100 m 2 of area, but not less than one for each separate room. The boxes are painted red and provided with a shovel and a shovel.

1.5.3 Occupational health and industrial sanitation

Working conditions at a car repair enterprise are a set of factors in the working environment that affect the health and performance of a person in the labor process. These factors are different in nature, forms of manifestation, nature of actions on a person.

Among them, dangerous and harmful production factors represent a special group. Their knowledge makes it possible to prevent occupational injuries and diseases, to create more favorable working conditions, ensuring its safety.

In accordance with GOST 12.0.003-74, hazardous and harmful production factors are divided into the following groups according to their impact on humans: physical, chemical, biological and psychophysiological.

Physical hazardous and harmful production factors, in turn, are divided into: moving machines and mechanisms, moving parts of production equipment, increased gas and dust pollution of the working area, high or low ambient temperature, insufficient lighting, crumbs and burrs on parts, tools and equipment.

Biologically hazardous and harmful production factors include: microorganisms, bacteria, viruses, fungi, their metabolic products

Psychophysiological dangerous and harmful production factors are divided into physical and neuropsychic stresses on a person.

To eliminate these factors at work stations and places of work, ATPs provide for fencing of rotating parts of parts and equipment, forced heating and ventilation, artificial lighting of premises, and work only with serviceable tools and devices.

When working with toxic or chemically hazardous materials at the workplace, forced exhaust ventilation, work in overalls and protective devices are provided.

The premises are cleaned daily with a disinfectant solution. At ATP, rooms for psychological unloading, the so-called rest rooms, are created. Manual labor is mechanized to reduce physical stress on repair workers. The locksmith must observe the rules of personal hygiene. Before eating or smoking, you must wash your hands with soap and water, and after working with the components and parts of a car running on leaded gasoline, you must first wash your hands with kerosene. It is prohibited to enter the dining room, red corner and other office premises in overalls used when working with parts of a car that ran on leaded gasoline.

1.5.4 Measures for nature protection

In accordance with the sanitary standards for the design of industrial enterprises, dusty or polluted with toxic gases, the air is removed by local ventilation devices and cleaned before being released into the atmosphere, taking into account local natural conditions. To purify the air removed from the premises, inertial and centrifugal dust separators and filters of various designs are used.

Inertial dust separators include single action settling chambers, labyrinth and centrifugal settling chambers. The separation of dust in such is based on a sharp decrease in the speed of movement of polluted air at the entrance to the chamber (up to 0.5 m / s), where dust particles, losing speed, settle to the bottom. If the dust is explosive, it must first be moistened.

Labyrinth dust collection chambers deposit dust due to a sudden sharp change in the direction of movement of dust-laden air. In this case, the suspended dust particles, which have an inertial force greater than air particles, continue to move in a given direction, hitting the walls of the labyrinth dust separator, lose speed and fall into the dust collector or hopper. The degree of air purification in the labyrinth dust separator depends on the composition and concentration of polluted air.

Centrifugal dust separators are designed for settling coarse dust and sawdust. The principle of operation is based on centrifugal force, under the influence of which suspended particles, pressing against the outer cylindrical or conical walls of the dust separator, lose speed and fall through the lower conical part to the outlet of the dust separator. The purified air with fine dust is thrown upwards through the exhaust pipeline. If used incorrectly, the dust in the cyclone can explode, so it is forbidden to install them in industrial buildings.

Multicyclones are small cyclones. The magnitude of the centrifugal force is inversely proportional to the distance of the particle from the axis of the cyclone; therefore, in cyclones of small diameter, the magnitude of this force increases. In addition, along with a decrease in the size of the cyclone, the distance from the inner cylindrical surface to the outer wall of the cyclone decreases, that is, the path of the particle before its deposition decreases. Cyclones of a smaller diameter have a high cleaning factor, so they are recommended for capturing fine, dry and light dust from air and gases. The performance of cyclones is limited, so several cyclones are combined into groups or batteries. Such cyclones are called battery cyclones.

To clean the air from dust in supply ventilation and air conditioning systems, the industry produces a wide range of filters. In addition, filters are produced to purify the air from microorganisms. Depending on the filter element, filters are divided into cloth, paper, fibrous and with filter material FP, hydraulic, electric and acoustic or ultrasonic.

In garages and repair shops, industrial wastewater is polluted with oil products, paintwork materials, toxic electrolytes, wood fibres, etc. Contaminated wastewater, when collected in a reservoir, must first be cleaned and neutralized, as it can pose a serious environmental hazard to reservoirs and soils.

The method of wastewater treatment depends on the degree of pollution, the self-cleaning ability of the reservoirs into which wastewater is discharged, and on the use of these reservoirs by the population.

There are several ways of wastewater treatment: mechanical, biological, physicochemical and combined.

The temperature of wastewater entering the sewer should not exceed 40 C. Contents harmful substances, before descending into the sewer, during mechanical cleaning should be reduced by 50-60%, after mechanical cleaning with biofiltration by 90-95%.

Mechanical cleaning of sewage mud pits is mandatory for motor transport enterprises with more than 50 vehicles, and at centralized service bases - if there are ten posts.

Dirt pits with manual sludge removal are cleaned weekly, and with mechanical sludge removal - daily. The release of wastewater into water bodies is allowed after checking the concentration of harmful substances in accordance with SN 245-73.4 by the sanitary authorities.

On the territory of the enterprise, waste oil products and special liquids are drained and stored in special containers. Periodically, as the containers are filled, oil products and special liquids are transported to the territory of the refinery, where they are subsequently processed. Units, assemblies and parts of vehicles that cannot be repaired are stored in a specially designated place. As they accumulate, they are handed over to the collection point for non-ferrous and ferrous scrap, and then they go for remelting.

1.6 Economic part

1.6.1 Calculation of the annual wage fund

Two workers work at the site, one minder of the sixth category, the second of the fourth category with tariff rates of 30.2 and 25.4, respectively. Junior service personnel - one person with a salary of 2500 rubles.

To calculate the wages of employees, it is necessary to calculate the average monthly working time fund using the formula:

, h

D to– calendar days (365 days)

IN - holidays per year (106 days)

P– public holidays per year (12 days)

t rd – work time per day (8 hours)

t rd- the number of pre-holiday days in a year reduced by 1 hour

For a minder of the 6th category

For minder 4 category

Now we consider the average monthly wage fund with northern, regional and bonuses for minders and MOS

For a minder of the 6th category

For minder 4 category

Junior service personnel (1 person).

The total payroll will be:

FOT = 11610.69 rubles. + RUB 9765.28 +5875 rub. = 27250.98 rubles.

The annual payroll will be:

FOT = 27250 rubles. * 12 months = 327011.712 rubles.

Deductions to off-budget funds (single social tax) will be:

To the pension fund (PFRF - 20%)

Social Insurance Fund (FSSRF - 2.9%)

Compulsory Medical Insurance Fund (FFOMS + TFOMS = 3.1%)

Total deductions 26% of the wage fund

The fees will be:

PFRF \u003d 327011.71 rubles. * 28% = 5450.20, rub.

FSSRF = 27250.98 rubles. * 4% = 790.28 rubles

FOMS = 27250.98 rubles. * 3.6% = 844.78, rub.

Total UST = 27250.98 rubles. * 35.6% = 7085.25 rubles

Total deductions per year

UST = 7085.25 rubles. * 12 months = 85023.05 rubles.

Site costs per year

Z ph \u003d UST + PHOT \u003d 85023.05 rubles. + 327011.712 RUB = 412034.76 rubles.

1.6.2 Calculation of costs for materials and spare parts

For materials:

Cost rate per 1000 kilometers (200 rubles)

rub.

For parts

Cost rate for spare parts (1100 rubles)

Annual mileage of all cars in the fleet, km

TO– correction factor (take 1.3)

1.6.3 Calculation of energy costs

Table 11 Consumers of power electrical energy:

Calculate power consumption

, kWh

Total installed power of consumers (Table 11)

Coefficient of simultaneous operation (0.2 - shows that consumers of power electricity do not work simultaneously)

Annual number of hours of work (1993 hours working calendar for 2008)

Power energy costs

Rub. - the cost of 1 kW for enterprises (2.5 rubles)

Power consumption

Lighting costs

, rub. - total electricity consumption for lighting, the calculation was made in part: 1.4 Determination of the energy needs of production, point 1: lighting.

The cost of 1 kW for enterprises (2.5 rubles)

10160.6 , rub.

1.6.4 Calculation of heating costs

Heating costs are calculated using the formula:

, rub.

from– The cost of 1 ton of reference fuel is 10,000 rubles.

Mouth- Consumption of tons of standard fuel for heating, the calculation was made in part: 1.4 Determination of the energy needs of production, point 2: heating.

1.6.5 Calculation of water costs

Water costs are calculated using the formula:

Cold water costs

E- the total consumption of cold water per year (defined in part: 1.4 Determining the energy needs of production, point 5: water supply).

With VX- the cost of 1 m 3 of cold water (1 m 3 of water is 10.6 rubles + 18% VAT = 12.51 rubles)

1 m 3 \u003d 1000 l

Rub. VAT included

Hot water costs

E- the total consumption of hot water per year (defined in part: 1.4 Determining the energy needs of production, point 5: water supply);

With VG- the cost of 1 m 3 of hot water (1 m 3 of water is 94.4 rubles + 18% VAT = 111.39 rubles)

, rub. VAT included

Wastewater treatment costs per year

E- total water consumption for water supply (defined in part: 1.4 Determination of energy needs of production, point 5: water supply)

C with- the cost of 1 m 3 of wastewater (1 m 3 of water is 51.13 rubles + 18% VAT = 60.33)

, rub. VAT included

The total cost of water supply will be:

1.6.6 Calculation of equipment depreciation costs

Depreciation costs

, rub.

Art.- total cost of equipment (114,400 rubles, Table 10)

US– warranty period for all equipment is 8 years (Table 10)

Thesis *

3 590 rub.

Description

Organization of repair of KAMAZ 5320 trucks ...

INTRODUCTION 6
1 ANALYSIS OF THE ACTIVITIES OF THE ENTERPRISE 8
1.1 general characteristics enterprises 8
1.2 Organization of the technological process of engine break-in 9
1.3 Analysis of technical and economic indicators of the enterprise 14
2. MAIN PART 17
2.1 Analysis of the use of road transport in LLP "Auto Center" KamAZ "17
2.2 Size and structure of implementation costs transport work 17
2.3 Justification of the production repair program 19
2.4 Operating mode of the enterprise and funds of time 22
2.5 Annual calendar plan works and loading schedule 23
2.6 Production cycle schedule and justification of the repair method 27
2.8 Freight flow schedule and choice of material handling
assembly shop equipment 32
3. DESIGN 36
3.1 Engine break-in 36
3.2Design of the lubrication system 40
3.3 Design development of the stand - tilter for disassembly
and engine assembly 42
3.4 Strength calculations 44
4. SAFETY 47
4.1 Occupational safety issues in the operation of repair equipment 47
4.2. Analysis of the safety and harmlessness of the operation of repair and diagnostic equipment 47
4.3 Safety requirements for the operation of repair and diagnostic equipment 48
5 ENVIRONMENTAL PROTECTION 52
6 ECONOMIC EFFICIENCY 55
6.1 Calculation of the economic efficiency of the implemented structure 55
6.2 Calculation of the economic efficiency of the technological process of the aggregate section 57
6.3 Cost-effectiveness calculation and feasibility study 61
CONCLUSION 63
REFERENCES 64

Introduction

The relevance of the topic of our study pursues the organization of repair of KamAZ vehicles at a specialized repair enterprise, instead of poor-quality maintenance and repair in rural repair shops. As experience shows, the repair of complex components and assemblies of vehicles in agriculture carried out poorly due to the low equipment of the repair base. Repair shops do not have the necessary technological equipment for overhaul of trucks, and large enterprises prefer to engage in the most common type of repair - the repair of tractors and agricultural machines.

Bibliography

1. Afanasiev L.L., Ostrovsky N.B., Zuckerberg S.M. “Unified transport system and road transport". M., Transport 1984
2. Fastovtsev V.G. “Unified transport system and road transport”. Guidelines M., Transport 1986
3. “Regulations on the MOT and TR of the rolling stock of road transport” M., Transport, 1988
4. Kramarenko G.V. and etc. " Technical operation cars." M., Transport 1988
5. MIIAT Brief automobile (transport) reference book. M., Transport 1987
6. “Price list No. 07 - 02 dated 12.24.01. Wholesale prices for petroleum products”, TNK, 2 pp.
7. Ivorev S.A. “Economic issues in organizing the work of the ATP”, M., Higher School, 1991, 132 pages.
8. Dolik P.A. “Safety Handbook”, M., Energosetizdat, 1984
9. GOST 12.0.003-80 SSBT. "Dangerous and harmful production factors".
10. GOST 12.4.011 - 75 "Means of protection for workers".
11. Serov I.P. “Methods for determining wholesale prices for products of the machine-building complex”, M., Ekonomizdat, 1993
12. "Economic issues in the graduation project." Guidelines, Ryazan State Agricultural Academy, Ryazan 1999
13. Reshetov D.N. "Machine parts". Edition 4th. M., Mashinostroenie, 1989
14. “Depreciation rates and methods for determining wholesale prices for engineering products”, edited by Simonev A.A.. M., Economics, 1992
15. GOST 12.0.003 - 86 SSBT "Hazardous and harmful production factors".
16. Demin P.A. "Safety Handbook". M., 1988
17. Napolsky G.M. “Technological design of motor transport enterprises and maintenance stations”. Textbook for universities, M., Transport 1985
18. “Quick reference book of NIIAT”. M., Transport 1982
19. GOST 12.1.004 – 76 SSBT “Fire safety. General requirements”.
20. "Labor protection". Guidelines for diploma design, Ryazan State Agricultural Academy, Ryazan 1998
21. GOST 12.1.005 - 76 SSBT “Air in the working area. General sanitary and technical requirements”.
22. GOST 12.1.003 - 80 SSBT “Noise. General safety requirements”.
23. GOST 12.01.02 – 88 SSBT “Vibration. General safety requirements”.
24. SNiP II - 4 - 79 "Natural and artificial lighting".
25. Novak V.M. and others. “Handbook of a machine builder technologist”. M., Mechanical engineering 1983
26. Velikanov K.M. etc. “Productivity, economics and labor organization of a turner”. M., Mechanical engineering 1984
27. Aleksandrov L.A. “Technical regulation in road transport”. M., Transport 1978
28. Arshinov V.A., Alekseev T.R. "Metal cutting and cutting tools". M., Mechanical Engineering 1983.
29. Cherpakov S.S. “Maintenance and repair of buses”. M., Kolos 1978
30. Bokov V.N. "Machine parts". M., Higher School 1960
31. Kuznetsov E.S. "Technical operation of cars". Textbook for universities 3rd edition. M., Transport 1991, 413 pages.

Please carefully study the content and fragments of the work. Money for purchased finished work due to the non-compliance of this work with your requirements or its uniqueness, they are not returned.

* The category of work is estimated in accordance with the qualitative and quantitative parameters of the material provided. This material, neither in its entirety, nor any of its parts, is a finished scientific work, final qualification work, scientific report or other work provided for by the state system of scientific certification or necessary for passing an intermediate or final certification. This material is a subjective result of processing, structuring and formatting the information collected by its author and is intended primarily to be used as a source for self-preparation of the work on this topic.

Graduation qualifying work on the topic:

KAMAZ 740 engine cooling system.

Fulfilled

Introduction

1. Purpose, device, principle of operation.

2. Diagnostics and maintenance.

3. Main malfunctions and ways to eliminate them (maintenance)

4. Labor and environmental protection.

Bibliography

Introduction

1. Purpose, device, principle of operation.

Maintenance Precautions. In the conditions of ATP, measures are important that eliminate the harmful effects of exhaust gases, leaded gasoline, acids and other harmful materials on the health of workers during maintenance and repair of a car, loading and unloading operations. The room where car maintenance is performed must be well lit and kept clean. At night, maintenance can be carried out only with good artificial lighting, while using portable electric lamps with a voltage of not more than 36 V.

The safety of work largely depends on the serviceability of the tool used. When disassembling units and mechanisms, do not use wrenches that do not correspond to the size of the nuts, with the installation of linings in the mouth of the key; increase the key with another key; hit the wrench with a hammer when unscrewing the nuts; unscrew the nuts with a hammer and chisel. The handles of hammers and sledgehammers must be smooth, oval and free of cracks. The handle must firmly hold the hammer (or sledgehammer), for which a wedge of mild steel is driven into the end of the handle. The heads of hammers and sledgehammers must be free of burrs and cracks, with a smooth, slightly convex surface. A screwdriver for work is chosen so that the width of its working part is equal to the diameter of the screw head.

You can not stand on moving, especially round parts, as you can easily fall from them. In order to avoid tripping, no foreign objects should be left on the floor near the maintenance areas.

The alignment of the parts is checked using a mandrel - a metal rod. Under no circumstances should you use your finger for this purpose. To protect hands from injury when carrying large parts during disassembly and assembly operations, put on gloves.

Do not troubleshoot, adjust, lubricate or clean the vehicle while the engine is running.

fuel storage, lubricants And special liquids allowed in special containers. Leaded gasoline is tetraethyl lead, which causes severe poisoning of the human body. Do not use leaded gasoline to wash hands and parts, or suck it up by mouth with a hose. Leaded gasoline that has come into contact with the skin is neutralized by washing the skin area with kerosene or warm water and soap. If leaded gasoline gets into the eyes, rinse them with a 2% solution baking soda or warm water and seek medical advice.

It should be remembered that antifreeze is a poisonous liquid and if it enters the stomach and intestines, it causes poisoning. It is forbidden to pour liquid without rubber gloves, suck the hose with your mouth, and also smoke, take food while working with it.

The electrolyte is prepared in vessels made of acid-resistant material. Do not use glass jars for this purpose, which can break. It should be remembered that sulfuric acid vapors have a harmful effect on human health. Rooms where work is carried out on batteries must be well ventilated. When preparing the electrolyte, sulfuric acid is poured into water in a thin stream with continuous stirring. It is impossible to pour water into sulfuric acid in order to avoid a violent reaction, boiling and splashing out of the solution from the vessel. Care should be taken not to get electrolyte and acid on clothing and body, as skin burns are possible. Carrying batteries by hand is not allowed, it is recommended to use trolleys with sockets or special devices to carry them.

When draining hot oil from the engine sump, be careful not to burn your hands. The operation of the engine in enclosed spaces is allowed only for the arrival and departure of the car.

Environmental protection from pollution by oil products.

During the operation of vehicles, oil products can get into the soil and water bodies: diesel fuel, oil, gasoline. Getting into water bodies, they not only cover the surface with a film, but also dissolve throughout the entire water column, being deposited along with silt at the bottom. The presence of 0.1 mg of oil products in 1 liter of water gives the fish an irremovable aftertaste of oil and a specific smell. With large amounts of oil products in the water, it dies. The presence of oil products in the soil has a detrimental effect on plants.

To prevent oil pollution of the environment, the following precautions must be observed. Do not wash machine parts with fuel. Fuel sediment from fuel tanks and filters should be drained into only prepared containers. When pumping fuel during the removal of air from the diesel power system, it must be drained into a container.

At oil depots, maintenance points and repair shops, waste oil products must be collected in tanks or barrels in specially designated areas with appropriate signs.

Do not allow the engine to operate with increased smoke and the content of CO and CH above the permissible norm.

Bibliography:

1). .Car repair KAMAZ.- 2nd ed., revised. and additional - M.: Agropromizdat, 1991. - 320 p., ill.

2). , and etc. KamAZ vehicles: Maintenance and repair. - 2nd ed., revised. and additional - M.: Transport, 1988. - 325 p., ill., tab.

3). Manual for the repair and maintenance of vehicles KAMAZ-5320, -53211, -53212, -53213, -5410, -54112, -55111, -55102.- M .: Third Rome,

2000. - 240 p., ill.

https://pandia.ru/text/77/494/images/image002_52.jpg" align="left" width="643" height="482"> Fig. 5. Fan drive fluid coupling:

1 - front cover; 2 - bearing housing; 3 - casing;, 19 - ball bearings; 5 - tube of the bearing housing; 6 - drive shaft; 7 - hydraulic coupling drive shaft; 9 - driven wheel; 10 - driving wheel; 11 - pulley; 12 - pulley shaft; 14 - cuff sleeve; 15 - fan hub; 16 - driven shaft; 17, 20 - cuffs with a spring; 18 - gasket.

Fig.6. Thermostat:

1, 7 - racks; 2 - stock; 3, 12 - adjusting nuts; 4 - rubber insert with a washer; 6 - base; 8 - balloon: 9 - active mass (ceresin); 11, 13 - springs.