Robert Boschgmbh

Klaus Riel

Klaus-Jurgen Peters

Heinrich Knapp

Reinhard Schwartz

Gunther Jaggle

Walter Schlott

Reinhardt Schwartz

A fuel injection system for supercharged internal combustion engines is proposed, which serves to meter a quantity of fuel adapted to the quantity of air aspirated by the engine and also serves to regulate the fuel-air mixture in accordance with operating characteristics of the engine. The fuel injection system includes an air flow rate member, the restoring force of which is generated by means of pressure fluid in a control pressure line. The pressure of the pressure fluid in the control pressure line is variable in accordance with at least one pressure control valve, by means of which the pressure in the control line and thus the restoring force exerted upon the air flow rate member, which actuates a control slide of a metering and distribution valve assembly, can be reduced when the intake tube pressure downstream of a compressor increases. The result is that an undesirable leaning down of the fuel-air mixture caused by the error in air density can be corrected.

Fuel injection system

The control pressure valve assembly for a fuel injection system of an internal combustion engine provides variable fluid pressure which provides a restoring force against the fuel control plunger to alter the fuel-air ratio in dependence on engine and environmental variables. In particular, the fluid pressure is regulated by a spring loaded diaphragm valve which is also subjected to a variable closing force provided by an air pressure cell and by a first temperature sensitive element which opposes the forces of the spring and of the air pressure cell to provide decreased fluid pressure at low engine temperature and a second temperature-sensitive element to oppose the force of the air pressure cell only below a predetermined temperature.

Pressure control valve assembly

A fuel injection system for externally ignited internal combustion engines in which a fuel metering and distributing valve is controlled by an air sensing element disposed in the air suction tube of the engine and by structure which is adapted to alter the restoring force exerted on the air sensing element through the fuel metering and distributing valve. The noted structure includes a control pressure conduit, a pressure control valve connected to the control pressure conduit, a second conduit for connecting the pressure control valve to the suction tube of the engine downstream of the butterfly valve, and a third conduit for connecting the pressure control valve to the atmosphere or to the air suction tube downstream from an air filter. With this structure it is possible to alter the restoring force mentioned above so that an enriched fuel-air mixture is achieved when the butterfly valve is opened to its full load position, and so that a leaner fuel-air mixture is achieved when the butterfly valve is closed to a partial load position.

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Moglingen, Germany

Klaus Riel