Patent ID: 7406952

Claim:
A method for controlling an injector comprising a nozzle needle whose position is adjustable as a function of a pressure in a control chamber and which in a closed position prevents a fluid flow through at least one injection port and otherwise releases said fluid flow, the control chamber which is hydraulically coupled to a high-pressure fluid accumulator, a piezo actuator, and a control valve which in its closed position hydraulically decouples the control chamber from a low-pressure chamber which outside of the closed position hydraulically couples the control chamber to the low-pressure chamber and upon which the piezo actuator acts, the method comprising the step of: varying a combination of a control period of the piezo actuator and an electrical energy to be supplied to the piezo actuator starting from a predefined initial combination to a target combination in which a pressure curve is recorded which is characteristic of a movement of the control valve out of its closed position without a metering of fluid taking place through the injection port.