Abstract: A method of triggering a piezoelectric actuator which controls the injection of fuel into the combustion chamber of an internal combustion engine via a valve is described in which the operating situation of the engine is determined and the derivative with respect to time of the voltage, which can be picked off at the piezoelectric actuator, is selected as a function of the operating situation. Furthermore, a control unit for controlling a fuel injection system is described, in which a piezoelectric element is triggered so that the derivative with respect to time of the voltage, which can be picked off at the piezoelectric actuator, is adjusted to the operating situation of the engine. Additionally described is a fuel injection system, having at least one piezoelectric actuator which is triggered accordingly.

Abstract: A method and a device for transmitting an elastic deflection of a piezoelectric element to an actuator by using a direct voltage source, generated from a supply voltage, for charging or discharging the piezoelectric element. An actuating motion of the actuator is modified as a function of the control voltage of the piezoelectric element, the voltage gradient being simultaneously adjusted to the control voltage.

Abstract: A method and an apparatus for controlling system parameters, in particular for controlling the voltage applied to piezoelectric elements (10, 20, 30, 40, 50, 60) within a circuit (A) for charging and discharging piezoelectric elements (10, 20, 30, 40, 50, 60) are described. The method is characterized by modifying at least one control parameter for the control of a system parameter, in particular a target voltage for the voltage applied to a piezoelectric element (10, 20, 30, 40, 50, 60), in view of at least one systematic error occurring during a first control procedure of the system parameter to obtain a corrected control parameter for a second and/or a further control of the system parameter. The apparatus is particularly eligible for use with the inventive method.

Abstract: A method is proposed for diagnosing the drive voltage for a piezoelectric actuator of an injector, in which the drive voltage is measured for the individual phases of the injection procedure. With respect to each control phase, a corresponding tolerance band is provided, which is set using the setpoint value of the drive voltage. The tolerance ranges are established as a function of operating and/or environmental conditions. If, for the individual drive cycles, the corresponding tolerance ranges are not reached, then, in response to repeated measurement, these erroneous measurements are counted. When a preestablished number for the erroneous measurements is exceeded, then an ongoing error is diagnosed. If, after a certain time, the number is not exceeded, then the counter is reset. In the case of an error, the error storage unit can be reset using a maintenance plug-in device during maintenance.

Abstract: A fuel injection system having a fuel injection valve in which an injection valve member is urged in an opening direction counter to a closing force by pressure in a pressure chamber which generated by a high-pressure fuel pump driven by a cam. A control valve is actuated by a piezoelectric actuator triggered by an electric control unit by which a communication of the pressure chamber with a relief chamber is controlled. When the control valve is closed, the pressure chamber is disconnected from the relief chamber. The control valve has a control valve member coupled with the actuator via a hydraulic coupler. The actuator, after a charging phase, communicates with an associated voltage meter, and the voltage between the electrical terminals of the actuator is monitored for detecting the function of the control valve.

Abstract: A method of charging or discharging a piezoelectric element, in which electric charge carriers are transported back and forth between a supply voltage of a direct voltage source and a piezoelectric element in order to transmit an elastic deflection of the piezoelectric element to an actuator. An actuating movement of the actuator is modified as a function of the level of a voltage being applied to the piezoelectric element, a reduction of the level of the applied voltage being compensated for by at least one additional transmission of electric charge carriers during a holding phase of the piezoelectric element.

Abstract: A method and a device for transmitting an elastic deflection of a piezoelectric element to an actuator by using a direct voltage source, generated from a supply voltage, for charging or discharging the piezoelectric element. An actuating motion of the actuator is modified as a function of the control voltage of the piezoelectric element, the voltage gradient being simultaneously adjusted to the control voltage.

Abstract: The fuel injection system has a fuel injection valve (12) which has at least one injection valve member (34) by which at least one injection opening (36) is controlled, in which the injection valve member (34) is urged in an opening direction (35) counter to a closing force by the pressure prevailing in a pressure chamber (44) of the fuel injection valve (12); the pressure prevailing in the pressure chamber (44) is generated by a pump piston (18) of a high-pressure fuel pump (10) that is driven in a reciprocating motion by a cam (22); a control valve (54) actuated by a piezoelectric actuator (58) is provided, which is triggered by an electric control unit (53) by which, at least indirectly, a communication (71) of the pressure chamber (44) with a relief chamber is controlled; when the control valve (54) is closed, the pressure chamber (44) is disconnected from the relief chamber; and the control valve (54) has a control valve member (56), which is coupled with the actuator (58) via a hydraulic coupler (57).

Abstract: A Method and an apparatus for providing control parameters to or within a control system for controlling a fuel injection system are described. The method is characterized in that a plurality of control parameters is transmitted to storage means (810) within the control system by transmission means (850). The transmitted control parameters are stored within the storage means (810). Selection parameters are transmitted to selection means (800) within the control system by transmission means (840). Stored control parameters are selected in accordance with transmitted selection parameters by the selection means (800). And the selected parameters are utilized for controlling elements within the control system. The apparatus is in particular eligible for usage with a inventive method and is characterized in that a control unit (D) and an activation IC (E) are connected to each other by transmission means (840, 850). Storage means (810) are implemented in the activation IC (E).

Abstract: A method for determining the rail pressure of an injector including a voltage-controlled piezoelectrical actuator, the piezoelectrical actuator actuating a nozzle needle using hydraulic coupler. As a result of the pressure in the high-pressure channel, a coupler pressure is built up via the hydraulic coupler, the coupler pressure inducing a piezovoltage in the actuator. Because this voltage value is redundant with regard to the pressure value in the high-pressure channel, which is measured by a pressure sensor, the voltage value is used for monitoring the functioning of the pressure sensor. In the event of the failure of the pressure sensor, emergency operation is built up for the injector with the assistance of the induced voltage. The injector advantageously functions for injecting fuel in an internal combustion engine.

Abstract: An injector is proposed, in particular an injector for a combustion engine. It includes at least one nozzle module (3) which has an injection nozzle and a supply line for a fluid under a supply pressure (p_R), and a valve-control module (2), which is in operative connection with the nozzle module (3), and at least one valve-closure member (16) on which the supply pressure (p_R) acts, and includes a piezoelectric actuator (12) which is used to activate the valve-closure member (16) and which is prestressed by a spring (21) in the direction facing away from the valve-closure member (16), the piezoelectric actuator (12) being activated by a valve-control unit (30) which specifies a control gradient (dU/dt). The control gradient (dU/dt) is a variable that is dependent upon the supply pressure (p_R).

Abstract: Fuel injection system comprising a piezoelectric element for controlling the amount of injected fuel and further comprising a control unit for determination of a possible fault of the piezoelectric element or of an electric circuitry driving the piezoelectric element based upon a value related to the capacitance of the piezoelectric element.

Abstract: A valve (1) for regulating fluids has a piezoelectric unit (4) for actuating a valve member (3). The valve member is embodied with a control piston (9), adjacent to the piezoelectric unit (4), and with at least one actuating piston (14), adjacent to a valve closing member (15). A hydraulic chamber (16) functioning as a hydraulic booster is disposed between the pistons (9, 14). The valve closing member (15) cooperates with at least one valve seat (18, 19) and divides a low-pressure region (20) from a high-pressure region (21). An electric control unit (12) specifies the trigger voltage for the piezoelectric unit (4) as a function of the pressure level in the high-pressure region (21), a leakage loss from the low-pressure region (20) and the hydraulic chamber (16), and the refilling of the low-pressure region.

Abstract: A method and a device are described for detecting a fault current across a piezoelectric actuator (5) of an injector or its high voltage supply lead (6, 6a). Because the fault current upon contact with a person, for example, is relatively small compared to the useful current that charges or discharges the actuator, direct measurement of the current is not reliable. Therefore, it is suggested that, during the injection or in an injection pause, when the piezoelectric actuator (5) is charged, the voltage variation or a change in voltage (dU) be measured and the difference be compared to a predefined threshold value (S). When the threshold value (S) is exceeded, a fault message is produced, the voltage source is shut off, and/or the piezoelectric actuator (5) is discharged. The measured fault can be weighted using a counting algorithm. The method thus provides maximum protection upon contact, in particular for service personnel.

Abstract: Online optimization of injection systems having piezoelectric elements which are used, for example, as actuators in a fuel injection system of an internal combustion engine, wherein the piezoelectric element is activated by an activation voltage having a value set as a function of operating characteristics of the particular piezoelectric element, and based upon, for example, a correction value for injected fuel volume.

Abstract: A method is proposed for diagnosing the drive voltage for a piezoelectric actuator of an injector, in which the drive voltage is measured for the individual phases of the injection procedure. With respect to each control phase, a corresponding tolerance band is provided, which is set using the setpoint value of the drive voltage. The tolerance ranges are established as a function of operating and/or environmental conditions. If, for the individual drive cycles, the corresponding tolerance ranges are not reached, then, in response to repeated measurement, these erroneous measurements are counted. When a preestablished number for the erroneous measurements is exceeded, then an ongoing error is diagnosed. If, after a certain time, the number is not exceeded, then the counter is reset. In the case of an error, the error storage unit can be reset using a maintenance plug-in device during maintenance.

Abstract: The invention describes a method and an apparatus for a fuel injection system with a piezoelectric element for controlling the amount of injected fuel by charging and/or discharging the piezoelectric element, wherein the fuel injection system comprises a current flow controller for charging and/or discharging the piezoelectric element based upon the gradient of a voltage across the piezoelectric element due to a charge the piezoelectric element is carrying.

Abstract: A method of charging or discharging a piezoelectric element, in which electric charge carriers are transported back and forth between a supply voltage of a direct voltage source and a piezoelectric element in order to transmit an elastic deflection of the piezoelectric element to an actuator. An actuating movement of the actuator is modified as a function of the level of a voltage being applied to the piezoelectric element, a reduction of the level of the applied voltage being compensated for by at least one additional transmission of electric charge carriers during a holding phase of the piezoelectric element.

Abstract: According to the present invention, a method is proposed for determining the rail pressure of an injector having a voltage-controlled piezoelectrical actuator, the piezoelectrical actuator (2) actuating a nozzle needle (11) using hydraulic coupler (4). As a result of the pressure in the high-pressure channel (13), a coupler pressure (Pk) is built up via the hydraulic coupler (4), the coupler pressure inducing a piezovoltage (Ui) in the actuator (2). Because this voltage value is redundant with regard to the pressure value in the high-pressure channel (13), which is measured by a pressure sensor (D), the voltage value can be used for monitoring the functioning of the pressure sensor (D). In the event of the failure of the pressure sensor (D), emergency operation can be built up for the injector (1) with the assistance of the induced voltage (Ui). The injector (1) advantageously functions for injecting fuel in an internal combustion engine.

Abstract: A method of triggering a piezoelectric actuator which controls the injection of fuel into the combustion chamber of an internal combustion engine via a valve is described in which the operating situation of the engine is determined and the derivative with respect to time of the voltage, which can be picked off at the piezoelectric actuator, is selected as a function of the operating situation. Furthermore, a control unit for controlling a fuel injection system is described, in which a piezoelectric element is triggered in such a way that the derivative with respect to time of the voltage, which can be picked off at the piezoelectric actuator, is adjusted to the operating situation of the engine. Additionally described is a fuel injection system, having at least one piezoelectric actuator which is triggered accordingly.