15.4. Turbocompressor

Fig. 15.46. Scheme of a turbo-supercharging: 1 – pressure sensor; 2 – nozzle; 3 – aktyuator; 4 – perepuskny valve; 5 – turbine wheel; 6 – turbocompressor; 7 – from the air stream measuring instrument; 8 – ignition switch; 9 – control lamp of a turbocompressor; 10 – the warning buzzer; 11 – control unit


Fig. 15.47. Scheme of operation of the perepuskny valve of a turbocompressor: and – the valve is closed; b – the valve is open; 1 – a stream of the fulfilled gases; 2 – perepuskny valve; 3 – turbine wheel; 4 – turbocompressor wheel


The system of a turbo-supercharging is intended for speeding up of the engine due to increase in pressure of fuel-air mix on an entrance to the combustion chamber by means of the turbocompressor put in action by a stream of the fulfilled gases (fig. 15.46). The turbo-supercharging improves filling of cylinders fuel-air mix. Air pressure in an inlet collector is controlled by the perepuskny valve of a turbocompressor integrated with an aktyuator (the valve is put in action from the sprung rod which moves under the influence of pressure on an inlet collector). The valve directs a part of the fulfilled gases by turbine shovels, thereby regulating amount of the forced air (fig. 15.47). On model with a turbo-supercharging of later releases the intermediate cooler intended for cooling of air on an entrance to a turbocompressor is established (fig. 15.47).

Check of a turbocompressor
The design of a turbocompressor is rather simple, however this precision unit can easily fail at violation of supply of oil or cooling liquid or owing to weakening of fastening or mechanical damage of pipelines. Diagnosing and service of the unit is carried out by certain techniques by means of the special equipment therefore for search of malfunctions it is necessary to address to the autoservice center or a specialized workshop. However in garage conditions it is possible to check an integrity and correctness of connections, and also tightness of system, to remove and establish a turbocompressor, thereby having saved on the cost of works on its replacement.
Own, published during the work noise therefore change of noise peculiar to this unit can be a malfunction sign is characteristic of each turbocompressor. The whistling sound of high-pitch tone can demonstrate leak of gas from an inlet or final collector. If the turbocompressor makes an unusual sound, hand over it in service of car service or in a specialized workshop for repair. Periodically check a final collector as existence of cracks and weakening of connections is not allowed. Frequency of rotation of the turbine reaches 140 000 min.-1 therefore the termination of intake of cooling liquid or pollution of oil for lubricant of bearings can lead to serious destructions. Check tightness of the pipelines bringing cooling liquid and oil. A sign of violation of tightness are traces of the burned-out oil on a turbocompressor casing.

PREVENTION
Replacement of bearings of the engine, such as radical, conrod bearings or bearings of the camshaft, it is expedient to combine with washing of a turbocompressor with pure engine oil.

Removal and installation of a turbocompressor
Merge cooling liquid from the cooled-down engine.
Remove the ignition distributor.

Fig. 15.48. Elements of system of a turbo-supercharging: 1 – air tube; 2 – the top isolating casing; 3 – an oil pipeline (to a turbocompressor); 4 – secondary air tube; 5 – air inlet and air hose; 6 – recirculation valve tube; 7 – sensor of concentration of oxygen; 8 – the lower isolating casing


Remove an air inlet and an air hose (fig. 15.48).
Pick up the air phone.
Remove the lower isolating casing.
Pick up the secondary phone of air supply.
Remove an oil pipeline from a turbocompressor.
Remove the top isolating casing.
Disconnect a recirculation valve tube from a final collector.
Remove hoses of cooling liquid.
Remove the sensor of concentration of oxygen from a final collector.
Remove a forward exhaust pipe from catalytic converter.
Turn off bolts of fastening of a turbocompressor to an arm.
Turn off bolts of fastening of a final collector and remove a turbocompressor assembled with a final collector and a forward pipe.
Turn off nuts of fastening of a final collector and a forward pipe to a turbocompressor.
Check radial and axial side plays of a rotor of a turbocompressor. If the axial or radial side play is felt, the turbocompressor is subject to replacement.
Before installation grease turbocompressor bearings for what enter 25 cm3 of engine oil into a lubricant opening of a turbocompressor.
Attach a final collector and a forward pipe to a turbocompressor. Replace laying. Tighten nuts the required moment.
Further installation is carried out to the sequences, the return to removal.
Before launch of the engine disconnect a wire from a negative conclusion of the coil of ignition. For increase in pressure of oil and filling of the lubrication system turn during 20 with a starter a bent shaft of the engine. Attach a wire to a negative conclusion of the coil of ignition and launch the engine. It is possible to increase the frequency of rotation of a bent shaft of the engine not earlier than through 30 from later start-up.