Piezoelectric fuel injector operating method in which the residual actuator charge just prior to an injection event is measured so that subsequently a charge is applied such that the total charge corresponds to a set value

摘要

The fuel injector (200) is controlled using a control valve (230) with a piezoelectric actuator (210). The piezoelectric actuator is controlled with an electrical control value, the charge of the actuator. The magnitude of the charge is set so that it is just large enough to open the control valve during an injection event. The inventive method involves measuring the residual charge on the actuator just prior to the next injection and then applying a different amount so that the total charge magnitude corresponds to the set charge magnitude. An independent claim is made for a control unit (100) for controlling a piezoelectric fuel injector.