Determining the Movement Behavior Over Time of a Fuel Injector on the Basis of an Evaluation of the Chronological Progression of Various Electrical Measurement Variables

摘要

A method for determining the movement behavior of a fuel injector having a coil drive includes: (a) applying an electrical excitation to a coil of the coil drive, which prompts an opening movement of a valve needle; (b) recording the temporal progression of a first electrical measurement variable of the coil; (c) determining the time when the opening movement ends based on the recorded temporal progression of the first electrical measurement variable; (d) modifying the electrical excitation of the coil such that the valve needle performs a closing movement; (e) recording the temporal progression of a second electrical measurement variable of the coil; and (f) determining the time when the closing movement ends based on the recorded temporal progression of the second electrical measurement variable. One of the two measurement variables is the voltage present at the coil and the other is the intensity of current flowing through the coil.