Continental Automotive Gmbh

Vitesco Technologies Gmbh

Michael Katzenberger

Robert Hoffmann

Manfred Kramel

Nicolas Nozeran

Michael Kausche

Simon Ruscheinski

Various embodiments include a method for actuating a piezo actuator of an injection valve of a fuel injection system comprising: determining actuation signals for the piezo actuator using a stored current/voltage characteristic curve for carrying out an injection process; detecting the profile of the current flowing through the piezo actuator during the injection process and the profile of the voltage applied to the piezo actuator during the injection process; adapting the stored current/voltage characteristic curve based at least in part on the detected current profile and the detected voltage profile; and determining actuation signals for the piezo actuator using the stored, adapted current/voltage characteristic curve for carrying out a subsequent injection process.

Actuator for a piezo actuator of an injection valve

A method is disclosed for determining the idle travel of a piezo-injector which has a piezo-actuator and a nozzle needle which is activated directly by the piezo-actuator. A test pulse is applied to the piezo-actuator, which pulse brings about a continuous increase in the piezo-travel. The time period is measured which passes between the starting of the test pulse and the time when the idle travel is overcome. The idle travel of the piezo-injector is then determined from the measured time period.

Method for determining the idle travel of a piezo-injector with a directly actuated nozzle needle

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.

Growing community of inventors

Wuppertal, Germany

Michael Katzenberger