Abstract: A method for operating an injection valve, in particular a fuel injector of an internal combustion engine, in which a trigger voltage is able to be applied to an actuator, designed as piezoelectric element, of the fuel injector in order to induce an injection of fluid, in particular fuel, supplied to the fuel injector via a supply system. A specifiable test voltage is applied to the actuator in a test triggering, and a fluid pressure prevailing in the supply system is detected at least during the test triggering in order to derive information about an operating state of the fuel injector and/or the actuator from the test voltage and the detected fluid pressure.

Abstract: In a method for ascertaining the control voltage of a piezoelectric element, the voltage drop at the piezoelectric element following a charge process is measured and the control voltage of the piezoelectric element is inferred from this voltage drop.

Abstract: A method for operating an injection valve, in particular a fuel injector of an internal combustion engine, in which a trigger voltage is able to be applied to an actuator, designed as piezoelectric element, of the fuel injector in order to induce an injection of fluid, in particular fuel, supplied to the fuel injector via a supply system. A specifiable test voltage is applied to the actuator in a test triggering, and a fluid pressure prevailing in the supply system is detected at least during the test triggering in order to derive information about an operating state of the fuel injector and/or the actuator from the test voltage and the detected fluid pressure.

Abstract: A method for diagnosing a fuel injection device which includes a piezoelectric actuator, with which a valve element is actuated. The fuel injection device is connected to a diagnostic device which applies a defined voltage to the piezoelectric actuator. The charge introduced into the piezoelectric actuator, and from that a capacitance of the piezoelectric actuator, are ascertained by means of the diagnostic device.

Abstract: A method for determining the activation voltage of a piezoelectric actuator of at least one injector which is used to inject a liquid volume under high pressure into a cavity, in particular into a combustion chamber of an internal combustion engine, the activation voltage being varied as a function of the pressure used to pressurize the liquid volume. A drift of the activation voltage (voltage requirement) required for a predefined lift of a control valve of the injector is controlled on an injector-specific basis by controlling the difference between the cutoff-voltage threshold and the final steady-state voltage to a setpoint value predefined for one operating point.

Abstract: A method for determining the activation voltage of a piezoelectric actuator of at least one injector which is used to inject a liquid volume under high pressure into a cavity, in particular into a combustion chamber of an internal combustion engine, the activation voltage being varied as a function of the pressure used to pressurize the liquid volume. A drift of the activation voltage (voltage requirement) required for a predefined lift of a control valve of the injector is controlled on an injector-specific basis by controlling the difference between the cutoff-voltage threshold and the final steady-state voltage to a setpoint value predefined for one operating point.

Abstract: In a method for ascertaining the control voltage of a piezoelectric element, the voltage drop at the piezoelectric element following a charge process is measured and the control voltage of the piezoelectric element is inferred from this voltage drop.

Abstract: A method for diagnosing a fuel injection device which includes a piezoelectric actuator, with which a valve element is actuated. The fuel injection device is connected to a diagnostic device by means of which a defined voltage is applied to the piezoelectric actuator. The charge introduced into the piezoelectric actuator, and from that a capacitance of the piezoelectric actuator, are ascertained by means of the diagnostic device.