Repair of automotive engines. (1987)

A tractor with a harrow is driving through the field.

Tractor motor.

A cartoon showing the operation of a tractor engine.

A list of engine malfunctions that are subject to major repairs.

Before disassembly, the engine is washed with a hot solution in special chambers.

Disassembly of engines is carried out on production lines or special stands, while the disassembly procedure is the same.

The main parts are disassembled into assembly units.

Engine parts packed in metal baskets pass through the washing machine.

The carbon is removed with a sandblasting machine.

Washed and drained parts fall into the defect.

During defecation, they are monitored and sorted into suitable without restoration, repairable and unusable.

Unusable parts are sent to scrap.

Disassembly of the part on which the damaged areas are marked.

In case of breakages and cracks in the nests of the sub-plates of the main bearings and in places inaccessible for repair.

Samples of such damages.

Cracks and holes are welded, worn-out seats under the liners of the main bearings are restored by metal surfacing.

Then the holes for the main bearings are drilled in one pass with cutters mounted on the side rods.

A cartoon showing the grinding of an engine part.

Worn and damaged cylinder surfaces are restored by boring to fit the repair size of the sleeves.

The inner surface of the sleeves is restored with wear-resistant metal powders, which are welded to the surface of the sleeve by high-frequency currents.

As a result, a solid surface that does not require heat treatment is obtained.

Then the sleeves are drilled and brought to the nominal size by honing.

Surface quality check.

Finished sleeves.

The sleeves pressed into the block are honed on automatic machines.

After the repair, the unit is monitored and tested for the tightness of the water jacket.

When the crankshafts are defective, shafts with chips and cracks in the shaft necks are discarded.

A cartoon showing the wear of the root and connecting rod necks.

The process of measuring the size of necks using an indicator.

During a comprehensive check of the crankshaft, the runout of the root necks and the runout of the flywheel mounting flange are determined.

In cases where all repair dimensions are used and further reduction of the shaft diameter is unacceptable, the necks are restored by surfacing.

The surfacing is performed under a layer of loose flux, which protects the arc burning zone and molten metal from oxygen and nitrogen in the air.

Gorenje

As a result, the surfacing received a hard wear-resistant surface.

After that, the connecting rod and root necks of the crankshaft are adjusted to the nominal size of a circular grinding machine.

When the connecting rods are defective, the wear of the holes of the lower and upper heads is determined, as well as the torsion of the rod, which is corrected with a special device, and the curvature, which is corrected under the press.

Many parts restore settling based on electrolysis.

During electrolysis, electrolytic iron builds up on the surface of the part, this method restores the lower hole of the connecting rod head.

After settling, the end surfaces of the connecting rod head are ground, and the inner surface of the hole is honed.

When the hole under the bushing of the upper connecting rod head is worn out, new bushings are pressed, then they are drilled to the nominal size.

When the camshaft is defective, the runout of the intermediate support necks is checked with the help of an indicator.

When bending, the shaft is rejected.

Determine the wear of the cams and support necks.

The supporting shaft necks are restored by settling or welding a steel strip.

Worn cams are melted and then processed on a copy-grinding machine.

Such a machine gives the cams a given shape.

The most common defect of valves is wear and bending of the rod.

The bend is corrected under the press in a cold state.

The working chamfers of the plate are restored by surfacing.

Currently, plasma surfacing of hard alloys is used.

Valves after turning come to grinding.

In the rocker arm of the valves, the bushings wear out, which are replaced with new ones.

The worn spherical surface of the rocker sock is restored by grinding.

The main defects of the cylinder heads are cracks, warping of the interface surface with the cylinder block, wear of holes in the valve guide bushings, weakening of the valve seats in the sockets.

Cracks and sinks are brewed, they can also be sealed with epoxy pastes, while the treated surface is thoroughly cleaned.

After solidification of the epoxy composition with metal powder, the cylinder head is milled.

Valve sockets are restored by milling.

On special machines, the working chamfers of sockets and valves are lapped.

Lapping should ensure a tight, hermetic connection of the working chamfers of the valve and the seat, eliminating the possibility of gas penetration.

The quality of lapping is checked on a stand, with the help of which an excess air pressure is created over the valves.

Each combustion chamber has its own pressure gauge.

The pressure should not decrease for one minute.

In conclusion, the cylinder head is subjected to hydraulic tests, as well as when testing the block.

After disassembly, all parts of the diesel engine power system are washed and defective.

A cartoon explaining the main defects of fuel pumps.

Repair of fuel pump parts is carried out by previously shown means, welding, cooling, grinding, setting new bushings.

The plunger pair is not disassembled and restored by chrome plating only the plunger.

Then the plunger pair is checked for tightness on special devices.

After repair and replacement of worn parts, fuel pumps are assembled on the production line.

The assembled fuel pumps are adjusted, adjusted and tested on stands.

The assembled nozzles are checked for tightness, spray quality, injection pressure is adjusted and subjected to running-in.

When gasoline consumption increases and operating modes are not provided, the carburetor is disassembled and the parts are washed in kerosene.

Determine the malfunction

Carburetor parts.

Cartoon explaining the main defects of the carburetor.

Cartoon explaining the main defects of the oil pump.

Details of the oil pump.

They are restored by the methods already listed.

The surface of the pump cover is restored by grinding.

Worn gears are replaced with new ones.

After repair and assembly, the oil pump is tested with the filter of the same pump.

The oil filters are washed and, if necessary, the filter elements are replaced.

Elements of the cooling system.

In the cooling system, malfunctions in the water pump, chips and cracks in the housing, bending and wear of the roller, wear of the keyway are determined.

The parts are restored by brewing, grinding, installing new bushings.

Assembled water pumps undergo hydro-testing.

The main defects of the radiator are leakage in pipes and tanks, contamination, scale formation.

Leaks are sealed, internal tubes with a leak are silenced.

Crumpled plates are ruled by a special rule.

The scale in the tanks and tubes is removed with a special solution.

The assembly of the engine during repair is similar to the assembly at the factory.

Before installation, the crankshaft assembly with a flywheel is balanced on a special machine.

After assembly, the engine is sent to a test station, where it is worked on and tested.

The engine on the stand goes through three stages of running-in.

Cold.

Hot without load and hot under load.

At the last stage, the final preparation of the friction surface for the operation of the engine takes place.

Prepared engines.

The tractor pulls into the parking lot near the service station.

View of the truck parking lot.