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Overview
| Fig. 3.12. Scheme turbocharger 1 - compressor rotor; 2 - the turbine rotor; 3 - wastegate; 4 - a tube connecting the pressure regulator to the intake manifold
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A number of diesel engines installed in automobiles Golf III / Vento, equipped with turbocharging. The main element of the system is a turbocharger, an overpressure due to the kinetic energy of the exhaust gas (Fig. 3.12). It is mounted on the exhaust manifold. Lubrication and cooling are provided by the turbocharger rotor through the oil pipe, which is connected to the engine oil filter. The oil returns to the sump through the return line, which is connected to the cylinder block side. The turbocharger includes a built-in valve and the executive vacuum diaphragm which is used to control the boost pressure supplied to the intake manifold.
| Fig. 3.13. Components and parts of turbo engine ?�AFN?�: 1 - intake manifold; 2 - the exhaust manifold; 3 - the supply of air from the air-to-air heat exchanger; 4 - a lining of the inlet pipeline; 5 - the exhaust manifold gasket; 6 - the heat shield; 7 - boost pressure relief valve; 8 - the turbocharger; 9 - from the crankcase ventilation system; 10 - air supply from the air filter; 11 - a drain oil line; 12 - an arm of fastening of the turbocharger; 13 - to the air-to-air heat exchanger; 14 - front exhaust pipe; 15 - a vacuum hose; 16 - pressure oil line; 17 - an arm
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On engines 1Z and AFN boost pressure is limited by a solenoid valve in accordance with the program of the electronic control unit. The value of resistance of the valve is 24-28 ohms (1Z), and 14-20 ohms (AFN). The engine design used AFN Variable Turbine Geometry (Fig. 3.13). Due to this design is optimized turbine speed, which allows to obtain a rapid achievement of the required value of the boost, respectively, and torque at low revs, which makes the engine much more flexible.
A WARNING Be careful in the operation and repair of diesel engines with turbocharging: number of faults may be erroneously attributed to the malfunction of the turbocharger. |
In engines 1Z and AFN applied heat exchanger (?�intercooler?�) to cool the incoming compressed air into the engine. Before replacement / repair of turbochargers ensure correct operation of these systems and adjustments Engine: injection timing, fuel supply, full load limiter, air filter, as well as leaks in the intake and exhaust tract and the presence of adequate compression in the cylinders. Possible signs of trouble turbocharging systems are the reduction of engine power, black or blue smoke at the outlet of the exhaust gases, excessive oil consumption, noise in the turbocharger, incomplete combustion of fuel, oil leaks out of the turbine. Basic information about turbochargers are given in the Table. 3.1.
A WARNING Speed the turbine comes up to 130 000 min-1, therefore the engine oil used for turbocharger, special requirements. Avoid scarcity and late replacement, entering the turbocharger items, timely maintenance of the turbocharger. |
To reduce the risk of breakage of the turbocharger, the following guidelines: - Do not even short of its oil "starvation"; - Do not make a sudden stop the engine (or immediately after) a high speed as the turbine continues rapid rotation without lubrication; - Do not let the engine full load before it will work on frequency of rotation of idling at least a minute; - After long trips let the engine run at idle speed at least a few minutes: the turbine should be cool; - Do not run the engine disconnected at the inlet duct of the turbocharger: the vacuum inlet can suddenly increase dramatically with an increase in engine speed, which is associated with the risk of aspiration of foreign objects, and the arrival of the turbine in complete disrepair.
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