Continental Automotive Gmbh

Vitesco Technologies Gmbh

Robert Hoffmann

Hartmut Wolpert

Steffen Lehner

Michael Katzenberger

Simon Ruscheinski

Hans-Jörg Wiehoff

Anselm Schwarte

Tany Gargiso

Nicolas Nozeran

Michael Kausche

Peter Matthias Ruße

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.

Method for identifying faulty components of a fuel injection system

A method for monitoring the condition of a piezoinjector of a fuel injection system is disclosed. The fuel injection is carried out in injection cycles, each of which comprises a filling phase, a holding phase, and an emptying phase. The discharge resistance is ascertained during the holding phase of the piezoinjector. Conclusions about the working order of the piezoinjector are drawn using the ascertained discharge resistance.

Method for monitoring the condition of a piezo injector of a fuel injection system

A method for actuating a piezoelectric actuator and a piezo injector of a fuel injection system having a nozzle needle which can be moved between the closed position and an open position by the piezoelectric actuator are disclosed. Current is applied to the piezoelectric actuator from a source for the duration of a charging time as a function of a required quantity of fuel, in order to move the nozzle needle into its opened position for a time period which is dependent on the required quantity of fuel. The charging time is selected according to the following relationships: t(p)=t(p) for TI&#x3e;tand t(p, TI)&#x2266;Ti for TI&#x2266;t.

Method for actuating a piezo injector of a fuel injection system

A method for detecting error-containing components of a piezo-injector in an internal combustion engine fuel-injection system is disclosed. The piezo-injector has a piezoelectric actuator and an injection needle driven thereby, and is configured for operation in a partial-stroke mode and a full-stroke mode. First, the internal combustion engine is brought to a defined operational point. Then, the time for the injector needle to strike its stop when said injector needle is opened, as well as the time for the injector needle to strike its needle seat again when said injector needle is closed, are measured. The measured times are compared to normal values determined at the test stand. Parameter(s) for the fuel-injection system are calculated, using different calculation models, and the results are stored. Finally, the calculated parameters of the different calculation models are compared to norm values determined at the test stand, and compared to one another.

Method for detecting faulty components of an electronically regulated fuel injection system of an internal combustion engine

A method is disclosed for determining the force acting on the nozzle needle of a directly driven piezo injector, in which an electrical voltage is built on the piezo actuator which drives the nozzle needle by means of a charging process. After the charging process has ended, the voltage at the piezo actuator is measured again. A voltage gradient is determined from consecutive voltage values. Conclusions of the force acting on the nozzle needle are drawn from the voltage gradients.

Method for determining the force conditions at the nozzle needle of a directly driven piezo injector

A method is disclosed for monitoring the state of a piezoelectric injector of the fuel injection system of an internal combustion engine, the piezoelectric injector having a piezoelectric actuator and a nozzle needle that can be moved by said piezoelectric actuator. The piezoelectric injector can be operated in a partial-stroke mode and a full-stroke mode. In the partial-stroke mode, the curve of an electrical parameter over time is recorded, the maximum value of the curve is determined, a constant parameter value that arises after the presence of the maximum value is determined, the duration between the presence of the maximum value and the reaching of the constant parameter value is determined, the difference between the maximum value and the constant parameter value is determined, and conclusions about the state of the piezoelectric injector are drawn on the basis of the determined duration and the determined difference.

Method for monitoring the state of a piezoelectric injector of a fuel injection system

In a method for localizing a fault location within a fuel injection system, when a critical fault is detected by the diagnostic function, a pulse or a series of pulses to the injectors is triggered by a control unit. By observing the voltage value and/or charge value at the injector, it is possible to localize the fault location within the fuel injection system.

Method for the localization of a fault location within a fuel injection system

A check is made to determine whether the capacitance value measured at a specific point in time corresponds to a capacitance value of a calculated further capacitance profile or the measured capacitance value is within two tolerance ranges.

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Ruhstorf/Rott, Germany

Robert Hoffmann