Method for Operating a Fuel Injection System and Fuel Injection System Comprising Fuel Injection Valves with a Piezo Direct-Drive

摘要

A method for operating a fuel injection system includes detecting the pressure prevailing in a pressure accumulator using a fuel injection valve piezo actuator that includes, in addition to the active piezo region used to actuate the closing element, a passive piezo region that acts as a pressure sensor. Using this pressure sensor, the closing element force acting on the passive piezo region, and therefore the pressure prevailing in the pressure accumulator, can be determined.

主权项

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.