It has long been recognized that it would be most desirable to provide a fuel system capable to operate at any engine speed at any pressure. A number of attempts have led to new fuel injection systems which now allow direct injection in passenger car diesel engines. One of these systems is presented in this paper. The desired fuel injection pressure is set independent of engine speed. The fuel quantity injected can be varied by the duration of the injection. Therefore a certain quantity of fuel can be obtained by combining fuel pressure and injection duration. It is important, however, to note that the crank angle increases with speed. Also the time delay for precombustion charge preparation (mixing of air and fuel) represents a certain crank angle. The timing of injection initiation is thus an other parameter to be controlled. As microprocessors become more widely accepted components in engine control, a system has been visualized and then realized whereby the duration of injection and the initiation of injection are controlled as a function of engine speed and throttle setting. The opening and closing of high pressure injection nozzles, however, requires strong forces which hardly can be generated by solenoids. A hydraulic force amplifier, therefore, has been incorporated in the fuel nozzle in such a way that the microprocessor controls small currents only. The injection system is best understood by the schematic drawing, where the identification of the components is listed. The fuel pump (a multicylinder constant displacement pump) is pressurizing all injectors over a common high pressure manifold. A pressure regulator maintains a selected constant pressure. The plenum chamber after the fuel pump evens out pressure pulsations.
A fuel injection system for passenger car diesel engines
Einspritzanlage für einen Pkw-Dieselmotor
1983
12 Seiten, 8 Bilder
Aufsatz (Konferenz)
Datenträger
Englisch
A fuel injection system for passenger car diesel engines
Kraftfahrwesen | 1983
|Common Rail - An Attractive Fuel Injection System for Passenger Car DI Diesel Engines
SAE Technical Papers | 1996
|"Bosch Diesel injection systems for passenger car engines"
Online Contents | 1998
|Injection Equipment to Improve Fuel Mixture in Passenger Car Diesel Engines with Direct Injection
British Library Conference Proceedings | 1997
|Common rail - an attractive fuel injection system for passenger car DI Diesel engines
Kraftfahrwesen | 1996
|