DETERMINATION OF THE MOVEMENT BEHAVIOUR OF A FUEL INJECTOR ON THE BASIS OF THE TIME INTERVAL BETWEEN THE FIRST TWO VOLTAGE PULSES IN A HOLDING PHASE

摘要

A method for determining the opening behaviour over time and/or the closing behaviour over time of a fuel injector having a coil drive is described. The method involves (a) applying a boost voltage to the coil drive in a boosting phase for moving a magnet armature of the coil drive from a closing position into an opening position, (b) applying a holding voltage to the coil drive in a holding phase for holding the magnet armature in the open position, wherein the holding voltage is applied in the form of a plurality of holding pulses with the result that a predefined holding current with a lower and an upper holding level is set, (c) detecting the time interval (ΔT) between the first holding pulse (H1) and the second holding pulse (H2), and (d) determining the opening behaviour over time and/or the closing behaviour over time of the fuel injector as a function of the detected time interval between the first holding pulse (H1) and the second holding pulse (H2).