METHOD FOR OPERATING A DIESEL COMMON-RAIL PIEZO-OPERATED SERVO INJECTOR, AND MOTOR VEHICLE

摘要

A method for operating a diesel common-rail piezo-operated servo injector, and a motor vehicle, are described. In the method, the provided piezo actuator is actuated as a sensor in order to measure the force exerted on the servo valve. Here, for every operating point, the correct charge quantity for the piezo actuator is determined in order that said piezo actuator produces the force contact with the servo valve such as is required for the force measurement, without influencing the injection process itself by opening the servo valve. This is realized by means of a combination of two method variants, specifically a partial charging of the piezo actuator and a partial discharging thereof. The corresponding piezo voltage is measured using both methods, and the results are compared with one another. In the case of sufficient correlation, the second method is implemented in ranges in which the first method cannot be implemented. In the case of insufficient correlation, the second method is not implemented. In this way, the sensor operating range of a piezo actuator is expanded. An associated control unit is configured for carrying out a method of said type.