Circuit for regulating injection system fuel pump, derives adaptive component of desired delivery volume from integral component if integral component above threshold for defined time

摘要

The circuit has a regulator for the delivery rate of the fuel pump, a pilot control unit and an adder unit that determines a control signal from regulating and pilot control values. The pilot control unit derives a pilot control value depending on a desired delivery volume. The circuit derives an adaptive component for the desired delivery volume from an integral component if the integral component is above a threshold for a defined time. The circuit has a regulator (20) that compares desired and actual fuel pressure values and determines a regulating value for the delivery rate of the fuel pump accordingly, a pilot control unit (19) and an adder unit (21) that determines a control signal from the regulating and pilot control values. The pilot control unit determines a pilot control value depending on a desired delivery volume and the regulator has proportional and integral regulating value components. The circuit derives an adaptive component for the desired delivery volume from the integral component if the integral component lies above a threshold for a defined period and the adaptive component is taken into account as part of the pilot control value. Independent claims are also included for the following: a method of regulating the delivery rate of a fuel pump for an internal combustion engine and a method of checking the operability of a fuel pump.