Method For Determining The Opening And/Or Closing Time Of The Nozzle Needle Of An Injection Valve

摘要

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.

主权项

1. A method for determining a nozzle needle opening time or closing time of in an internal combustion engine having a plurality of cylinders, each having a corresponding injection valve having a nozzle needle that is actuated directly by a respective piezo actuator, the method comprising:
for at least some of the plurality of cylinders, measuring a piezo voltage value or a piezo charge value at the piezo actuator of the injection valve corresponding to the respective cylinder during an injection pulse; calculating a median value of the plurality of measured piezo voltage values or piezo charge values of the piezo actuators of the plurality of cylinders as a mean value of the cylinders for corresponding injection pulse; and in response to detecting a fault, using the calculated median value as an equivalent value for determining at least one of an opening time or a closing time of a particular nozzle needle.