Fuel supply system

摘要

a fuel system for mixture-compressing internal combustion engines controls the pressure differential of the extraction air required for proportioning the fuel. The system includes a fuel proportioning device and a vane pump for generating a carrier air stream for transporting the fuel into the suction tube of the internal combustion engine. A control valve constructed as a differential pressure valve influences the air pressure at the fuel outlet area and consequently the differential pressure for fuel proportioning. The throttle point is located in the carrier air channel upstream from the fuel proportioning area. A change in differential pressure adapts the mixture composition for various operating conditions. The signal level of the differential pressure is determined by the pressure decrease at the air quantity measuring valve formed as a pivotal flap and reaches the air channel where it is superimposed by the negative pressure, generated by the vane pump, and can be stabilized by the differential pressure valve and can be varied in dependence on motor operating parameters. To generate adequately high signal levels in the higher load range, the carrier air channels open into a Venturi arranged upstream from the main throttle valve. During different operating phases of the engine, various devices make it possible to maintain an adequately high signal value of the differential pressure.