Abstract: A method for identifying faulty components of a fuel injection system is disclosed, wherein a secondary injection is performed individually by each injector during a test routine, after the secondary injection several predefined parameters of the fuel injection system are determined, and a combined assessment of the determined parameters is used to draw conclusions about whether or not components of the fuel injection system are faulty.

Abstract: A method for determining the opening energy of a fuel injector of an internal combustion engine includes (a) operating the engine in a steady-state operating state, wherein electrical excitation is applied to the fuel injector to cause a fuel injection in each working cycle of the engine, (b) applying additional electrical excitation to the fuel injector for subsequent working cycle(s) for a possible additional partial fuel injection, wherein the additional electrical excitation is initially insufficient to cause an additional partial fuel injection, (c) successively increasing the additional electrical excitation until an additional partial fuel injection occurs, which brings about a second operating state of the engine different from the steady-state operating state, (d) detection of the second operating state, and (e) determination of the opening energy for the fuel injector based on the energy of the additional electrical excitation needed to bring about the second operating state of the engine.

Abstract: A piezo-driven fuel injector is modeled by measuring the actuation current and the actuation voltage of the piezo injector, transforming the actuation current and the actuation voltage into the frequency domain, forming a complex conductance from the actuation current transformed into the frequency domain and the actuation voltage transformed into the frequency domain, and determining one or more parameters of the piezo injector from the complex conductance. Once the complex conductance is determined it is used to detect a fault in the piezo injector.

Abstract: A method for identifying faulty components of a fuel injection system is disclosed, wherein a secondary injection is performed individually by each injector during a test routine, after the secondary injection several predefined parameters of the fuel injection system are determined, and a combined assessment of the determined parameters is used to draw conclusions about whether or not components of the fuel injection system are faulty.

Abstract: An injection system for an injection system includes at least one injection valve for injecting fuel into an internal combustion engine. A closing element of the injection valve is moved in recurring injection cycles such that the closing element hits an upper stop at an actual opening time and/or hits a closing position at an actual closing time and thereby triggers a characteristic signal of a sensor element of the injection valve, wherein a signal course of the sensor element over time is detected and a part of the signal course contained in a searching time period of the injection system is examined, wherein a searching method is performed in subsequent injection cycles if the characteristic signal is not detected in said part of the signal course over time.

Abstract: An injection valve has a moveable nozzle needle that controls a dosing of fluid and a solid-state actuator that actuates the nozzle needle. To operate the injection valve, values of a characteristic for a load state of the actuator are detected at a predetermined sampling rate. A start reference time and end reference time are determined correlating in chronological terms to an operating phase in which the solid-state actuator is discharged to a predetermined reference state by absorbing the energy in a discharging resistor. A correction reference value is determined based on a detected value of the characteristic correlating to an end of the operating phase, and a predetermined reference value. A correction value pattern is determined based on the end reference time, the start reference time, and the correction reference value. The detected values of the characteristic for the load state are determined based on the correction value pattern.

Abstract: An injection system for an injection system includes at least one injection valve for injecting fuel into an internal combustion engine. A closing element of the injection valve is moved in recurring injection cycles such that the closing element hits an upper stop at an actual opening time and/or hits a closing position at an actual closing time and thereby triggers a characteristic signal of a sensor element of the injection valve, wherein a signal course of the sensor element over time is detected and a part of the signal course contained in a searching time period of the injection system is examined, wherein a searching method is performed in subsequent injection cycles if the characteristic signal is not detected in said part of the signal course over time.

Abstract: A method for determining the opening energy of a fuel injector of an internal combustion engine includes (a) operating the engine in a steady-state operating state, wherein electrical excitation is applied to the fuel injector to cause a fuel injection in each working cycle of the engine, (b) applying additional electrical excitation to the fuel injector for subsequent working cycle(s) for a possible additional partial fuel injection, wherein the additional electrical excitation is initially insufficient to cause an additional partial fuel injection, (c) successively increasing the additional electrical excitation until an additional partial fuel injection occurs, which brings about a second operating state of the engine different from the steady-state operating state, (d) detection of the second operating state, and (e) determination of the opening energy for the fuel injector based on the energy of the additional electrical excitation needed to bring about the second operating state of the engine.

Abstract: An injection valve has a moveable nozzle needle that controls a dosing of fluid and a solid-state actuator that actuates the nozzle needle. To operate the injection valve, values of a characteristic for a load state of the actuator are detected at a predetermined sampling rate. A start reference time and end reference time are determined correlating in chronological terms to an operating phase in which the solid-state actuator is discharged to a predetermined reference state by absorbing the energy in a discharging resistor. A correction reference value is determined based on a detected value of the characteristic correlating to an end of the operating phase, and a predetermined reference value. A correction value pattern is determined based on the end reference time, the start reference time, and the correction reference value. The detected values of the characteristic for the load state are determined based on the correction value pattern.

Abstract: A control method for a fuel injection valve for an internal combustion engine is disclosed, wherein at least one control signal for actuating a drive of the injection valve is generated in recurring injection cycles and as a function of a target stroke height of a closing element of the injection valve, wherein the drive is actuated by the control signal to lift the closing element to the target stroke height and the closing element is lifted to an actual stroke height by means of the drive, wherein at least one measured parameter correlated with the actual stroke height is captured and the actual stroke height is determined as a function of said at least one measured parameter, wherein the control signal is generated in at least one of the subsequent injection cycles as a function of a deviation of the actual stroke height from the target stroke height.

Abstract: A method for determining a position of a lock element of an injection valve for an internal combustion engine includes moving the lock element in the direction of a locked position in a closing movement in order to lock the injection valve, subsequently measuring a closure time at which the lock element arrives in the locked position, determining a time difference between the closure time and a preceding starting time of the closing movement, and determining, based on the time difference, a position which the lock element has assumed at the starting time of the closing movement.

Abstract: An injection nozzle has a nozzle needle that suppresses metering of fluid in a closed position and otherwise allows the metering of fluid. Furthermore, the injection valve has a solid-state actuator that acts on the nozzle needle. A first operating phase is performed for a closing operation in a first operating mode, during which first operating phase the solid-state actuator is discharged to a predefined part charge. Furthermore, a second operating phase is performed, during which the solid-state actuator is operated as a sensor. An operating duration of the second operating phase is predefined such that the closed position of the nozzle needle is reached during the operating duration. A third operating phase is performed, during which the solid-state actuator is discharged further to a predefined reference state. In a second operating mode, the first and second operating phases are carried out and the third operating phase is omitted.

Abstract: A method for determining the actual start of injection is performed by an actuating device for a piezo fuel injection valve and includes the following steps. First, a test injection is carried out with such a short actuation duration that a start of shut-off takes place at a time so early that the nozzle needle does not reach the open end position. Said time is predefined by the actuation and is therefore precisely known. Next, the closing time of the nozzle needle is then determined by measurement and evaluation of an electrical variable of the piezo direct drive. Once the closing time and the time of the start of shut-off are known, the actual start of injection is calculated back from the closing time via the start of shut-off. This permits an adequately precise determination of the actual injection quantity in almost every operating state of the internal combustion engine.