Continental Automotive Gmbh

Vitesco Technologies Gmbh

Hans-Joerg Wiehoff

Tany Gargiso

Walter Schrod

Manfred Kramel

Andreas Baier

Peter Matthias Russe

Stefan Ascher

Peter-Matthias Russe

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.

Determining the opening energy of a fuel injector

The present disclosure relates to internal combustion engines. The teachings thereof may be embodied in methods for determining a state of an injection valve of an internal combustion engine. Some methods may include actuating the piezo actuator in a pulse-width-modulated manner; recording the T on and/or T off switching times of the pulse-width-modulated piezo output stage of the piezo actuator; and evaluating the recorded switching times to derive the state of the injection valve.

Method for injection valves

The present disclosure relates to fuel injectors. The teachings may be embodied in a method for characterizing a hydraulic coupling element. The fuel injector may have a piston to pressurize a hydraulic medium and a pin connecting the piston to a piezoactuator. The method may include applying a charging current to the piezo actuator low enough that the leakage flow prevents a pressure differential and the nozzle needle remains closed; discharging the piezo actuator with a current high enough to release the mechanical connection between the piston and the pin; detecting when the piston impacts on the pin; and characterizing the coupling element based on the time between discharge and impact.

Method for operating a piezo injector

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.

Method and device for injecting fuel into an internal combustion engine

The present disclosure relates to methods for operating an injection valve. An example method may include capturing ACTUAL quantities constituted by actuator current or actuator charge and/or actuator voltage continuously during an injection process; reconstructing a dynamic progression of the nozzle-needle stroke of an injection valve on the basis of a model structure for a motion of the nozzle needle of the injection valve, ascertaining the DESIRED quantities constituted by actuator current or actuator charge and/or actuator voltage therefrom, wherein the dynamic progression of the nozzle-needle stroke is reconstructed via a simplified model structure by introduction of at least one discrete measured value pertaining to the injection valve into a basic model of the nozzle-needle motion; comparing the DESIRED quantities with the ACTUAL quantities; and minimizing the difference between the DESIRED quantities and the ACTUAL quantities.

Method for operating an injection valve

A method is provided for determining the opening and/or closing time of the nozzle pin in an injection valve in an internal combustion engine having a plurality of cylinders. The nozzle pin is directly driven by a piezo actuator. The piezo voltage and/or the piezo charge at the respective piezo actuator functioning as a sensor is measured for the corresponding injection pulse in a plurality of cylinders of the internal combustion engine, and the median value of the measured voltage and/or charge values of the piezo actuators for the plurality of cylinders for the corresponding injection pulse is calculated. The obtained median value is then used as a replacement value for determining the opening and/or closing time in case of non-detectability or disruption of the needle opening and/or needle closing information.

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Wuppertal, Germany

Hans-Joerg Wiehoff