METHOD FOR DETERMINING THE RAIL PRESSURE OF AN INJECTION VALVE HAVING AN PIEZOELECTRIC ACTUATOR

摘要

The invention relates to a method for determining the rail pressure of an injection valve having a voltage-controlled piezoelectric actuator. Said piezoelectric actuator (2) actuates a nozzle needle (11) by means of a hydraulic coupler (4). The pressure in the high pressure channel (13), via the hydraulic coupler (4), builds up a coupler pressure (Pk) that induces a piezovoltage (Ui) in the actuator (2). As this voltage is redundant with respect to the pressure in the high pressure channel (13) measured by a pressure sensor (D), it can used to monitor the function of the pressure sensor (D). If the pressure sensor (D) fails, an emergency operation for the injection valve (1) can be established using the induced voltage (Ui). The injection valve (1) is preferably used for injecting fuel into an internal combustion engine.