METHOD FOR DETERMINING THE VALVE OPENING MOMENT IN PIEZO SERVO-DRIVEN INJECTORS

摘要

The invention relates to a method for determining the valve opening moment in piezo servo-driven injectors, the piezo actuator being used as a sensor element. The voltage and charge are measured at the end of the charging process of the piezo actuator, on the basis of which measurement a provisional scaling factor is identified. In this way, an approximate value of the valve opening moment is obtained, at which point the voltage and charge are measured again. A new scaling factor is determined by means of a corresponding calculation operation. Finally, the valve opening moment is determined with the aid of said new scaling factor. The moment can thus be determined online.