Patent ID: 9556839
Date: 2017-01-31
CPC Classifications: F02D,F02M

Claim:
1. A method for operating a fuel injection system of an internal combustion engine, wherein the fuel injection system has a pressure reservoir, at least one injection valve with piezo direct-drive in which a piezoelectric actuator is in a direct drive connection with a closure element of the injection valve, a pressure sensor that detects a pressure in the pressure reservoir, and a control and regulating unit, wherein the piezoelectric actuator includes an active piezoelectric region used for actuating the closure element and a passive piezoelectric region that forms the pressure sensor for detecting the pressure in the pressure reservoir, the method comprising: determining a force acting on the passive piezoelectric region through the closure element, and determining the pressure in the pressure reservoir based on the determined force acting on the passive piezoelectric region; and regulating pressure in the fuel injection system based on (a) the pressure in the pressure reservoir determined using the pressure sensor and (b) a setpoint pressure value.