Abstract: A method for adapting an injection quantity in an injection system of an internal combustion engine of a mild-hybrid motor vehicle or motor vehicle having a starter-generator or integrated starter-generator is disclosed. In an operating phase in which the e-machine of the motor vehicle drives the internal combustion engine, at least one small-quantity test injection is performed into a cylinder of the internal combustion engine. The associated injection quantity is determined based on a resulting torque. Corresponding correction variables for the adaptation of the injection quantity are determined therefrom. The method may eliminate the need to perform test injections during overrun phases of the internal combustion engine.

Abstract: Various embodiments may include a method for operating a piezo-actuator in a piezo-operated injector for a fuel injection system comprising: producing a measuring pulse at a position at which the usable signal which is to be measured is expected; then producing a reference pulse which corresponds to the measuring pulse, in the same cycle; subtracting a first actuator voltage measured during the reference pulse from a second actuator voltage measured during the measuring pulse; using a resulting voltage signal difference to calculate a force sensed by the piezo-actuator; and using the force sensed to correct an injection amount for the injector.

Abstract: Various embodiments may include a method for operating a piezo-actuator in a piezo-operated injector for a fuel injection system comprising: producing a measuring pulse at a position at which the usable signal which is to be measured is expected; then producing a reference pulse which corresponds to the measuring pulse, in the same cycle; subtracting a first actuator voltage measured during the reference pulse from a second actuator voltage measured during the measuring pulse; using a resulting voltage signal difference to calculate a force sensed by the piezo-actuator; and using the force sensed to correct an injection amount for the injector.

Abstract: A method and a device for determining the minimum hydraulic injection interval of a piezo-servo injector are described. The closing time of the nozzle needle of the injector is determined on the basis of the characteristic pressure profile in the control spring chamber of the injector. By incrementally reducing the injection interval of a subsequent injection by successively advancing the timing of the start of actuation of a subsequent injection and continuing to observe the pressure profile in the control spring chamber, the smallest injection interval is obtained from the last iteration step in which closing of the nozzle needle of the preceding injection could still be detected in the characteristic pressure profile. Particularly precise determination of the minimum injection interval is possible with this method.

Abstract: A method and a device for determining the minimum hydraulic injection interval of a piezo-servo injector are described. The closing time of the nozzle needle of the injector is determined on the basis of the characteristic pressure profile in the control spring chamber of the injector. By incrementally reducing the injection interval of a subsequent injection by successively advancing the timing of the start of actuation of a subsequent injection and continuing to observe the pressure profile in the control spring chamber, the smallest injection interval is obtained from the last iteration step in which closing of the nozzle needle of the preceding injection could still be detected in the characteristic pressure profile. Particularly precise determination of the minimum injection interval is possible with this method.

Abstract: A method for adapting the injection characteristic of a fuel injection valve of an internal combustion engine to production-related tolerances is described. In the method, an injection quantity correction value is determined from the deviation of the idle travel and the deviation of the injection quantity of the injection valve before the operating phase of the injector. This injection quantity correction value is used to determine the injection-specific deviation of the injection quantity during the operating phase at the start of the operating phase of the injector in conjunction with the current deviation of the idle travel which is determined in the system. The injector-specific deviation of the injection quantity which is determined is used to correct the injection characteristic. As a result, changes in the injection quantity of an injector can be detected and corrected particularly precisely on the basis of production tolerances.

Abstract: A method for determining a closing characteristic of a valve of a piezo servo injector, including carrying out test charging of an actuator of the piezo servo injector in order to open the control valve and in order to reduce pressure in a control chamber of the piezo servo injector; incompletely discharging the actuator down to a residual partial stroke of the actuator; ascertaining a gradient profile of the pressure drop in the pressure accumulator during the residual partial stroke; and determining the closing characteristic of the control valve from the gradient profile of the pressure drop. The closing characteristic may be the closing time of the valve. The method further includes modifying or adapting a closing process for the valve based upon the determined closing time.

Abstract: A method for controlling pressure in a high-pressure region of an internal combustion engine includes adjusting a fuel outflow from the high-pressure region into a low-pressure region by means of an injector, which has a control valve adjusted by a piezo actuator and a control chamber. The method includes charging the piezo actuator by a first signal such that the control valve is moved from a closed position to a partially open position and fuel flows out from the high-pressure region into the low-pressure region, discharging the piezo actuator by a second signal such that the control valve is moved into the closed position, and partially discharging the piezo actuator by a third signal after the first signal and before the second signal. The method provides pressure control in the high-pressure region via an injector with high reliability even at high rail pressure.

Abstract: A method for analyzing the efficiency of a high-pressure pump of a fuel injection system includes analyzing the efficiency of the high-pressure pump with respect to individual pumping strokes of the high-pressure pump, detecting and analyzing the pressure build-up and the pressure drop for the individual pumping strokes, and drawing conclusions about the state of individual components of the high-pressure pump from the analysis of the pressure build-up or the pressure drop.

Abstract: A method for adapting an injection quantity in an injection system of an internal combustion engine of a mild-hybrid motor vehicle or motor vehicle having a starter-generator or integrated starter-generator is disclosed. In an operating phase in which the e-machine of the motor vehicle drives the internal combustion engine, at least one small-quantity test injection is performed into a cylinder of the internal combustion engine. The associated injection quantity is determined based on a resulting torque. Corresponding correction variables for the adaptation of the injection quantity are determined therefrom. The method may eliminate the need to perform test injections during overrun phases of the internal combustion engine.

Abstract: An electrically controllable electromechanical inlet valve (2a) which is closed in the currentless state and is held in the closed state by the force of a spring (2b), an outlet valve (5a), and a displacement element (6), the inlet valve is operated in a self-controlling operating mode after a start command is present. In the self-controlling operating mode, the rail pressure is built without knowledge of the phase position of the displacement element. During the self-controlling operating mode, the phase position of the displacement element is determined. After the phase position of the piston or displacement element is determined, the inlet valve is switched over to a non-self-controlling operating mode.

Abstract: A method is provided for operating an internal combustion engine having an injection system comprising at least one injector indirectly driven by means of an actuator, and a high pressure accumulator. According to the method, the actuator of the at least one injector has electrical test pulses of iteratively increasing energy continuously applied thereto, and the idle stroke of the actuator is continuously determined by hydraulic and/or electric means. Upon detecting a change in the idle stroke, a corresponding correction of the injection time of the injector is carried out.

Abstract: A method for controlling pressure in a high-pressure region of an internal combustion engine includes adjusting a fuel outflow from the high-pressure region into a low-pressure region by means of an injector, which has a control valve adjusted by a piezo actuator and a control chamber. The method includes charging the piezo actuator by a first signal such that the control valve is moved from a closed position to a partially open position and fuel flows out from the high-pressure region into the low-pressure region, discharging the piezo actuator by a second signal such that the control valve is moved into the closed position, and partially discharging the piezo actuator by a third signal after the first signal and before the second signal. The method provides pressure control in the high-pressure region via an injector with high reliability even at high rail pressure.

Abstract: A method for analyzing the efficiency of a high-pressure pump of a fuel injection system includes analyzing the efficiency of the high-pressure pump with respect to individual pumping strokes of the high-pressure pump, detecting and analyzing the pressure build-up and the pressure drop for the individual pumping strokes, and drawing conclusions about the state of individual components of the high-pressure pump from the analysis of the pressure build-up or the pressure drop.

Abstract: A method provides for detecting deviations of injection quantities for injections into internal combustion engines, as carried out for example by common-rail systems. At least one deviation of at least one injection quantity is detected by determining at least one deviation, from a predefined value in each case, of at least one value of at least one variable controlling an actuator of the injector and/or indicating at least one state of the actuator.

Abstract: In a method for adapting the performance of a fuel prefeed pump of a motor vehicle which has a common rail injection system and an internal combustion engine, after the ignition is switched on and before the internal combustion engine is started, adaptation values are determined and stored which are assigned to the fuel prefeed pump and describe its individual performance. After the internal combustion engine is started, the stored adaptation values are taken into consideration during the determining of an actuating signal for the prefeed pump.

Abstract: In a method for determining the rail pressure in a common rail system of an internal combustion engine, at least one measurement variable is determined which is a measure for the angular velocity of a crankshaft movement of the internal combustion engine, and the rail pressure is determined from said measurement variable or from a variable derived from the measurement variable. Furthermore disclosed are methods that are based thereon for controlling an injection quantity and for controlling a rail pressure, and a corresponding common rail injection system.

Abstract: A method for adapting the injection characteristic of a fuel injection valve of an internal combustion engine to production-related tolerances is described. In the method, an injection quantity correction value is determined from the deviation of the idle travel and the deviation of the injection quantity of the injection valve before the operating phase of the injector. This injection quantity correction value is used to determine the injection-specific deviation of the injection quantity during the operating phase at the start of the operating phase of the injector in conjunction with the current deviation of the idle travel which is determined in the system. The injector-specific deviation of the injection quantity which is determined is used to correct the injection characteristic. As a result, changes in the injection quantity of an injector can be detected and corrected particularly precisely on the basis of production tolerances.

Abstract: A method is provided for operating an internal combustion engine having an injection system comprising at least one injector indirectly driven by means of an actuator, and a high pressure accumulator. According to the method, the actuator of the at least one injector has electrical test pulses of iteratively increasing energy continuously applied thereto, and the idle stroke of the actuator is continuously determined by hydraulic and/or electric means. Upon detecting a change in the idle stroke, a corresponding correction of the injection time of the injector is carried out.

Abstract: When the internal combustion engine is in an injection-free operating mode, a selected injector is open for injecting a small fuel amount, whereby at least one working cycle with injector control follows or precedes one cycle without control, a differential of two subsequent segment times of the cylinder associated with the selected injector or another variable, that reproduces a temporal crankshaft angle speed modification, is determined as a measurement value respectively for the cycle with and without control, and a relation is formed between the values of the cycles with or without control and used to correct the injection characteristic curve. The engine operates with active ignition and the value for the cycle with control is tested by taking into account ignition faults and the relation is only used to correct the curve if the value in the cycle with control significantly deviates from the one without control.