Method for determining the rail pressure of an injector having a piezoelectrical actuator

Abstract

A method for determining the rail pressure of an injector including a voltage-controlled piezoelectrical actuator, the piezoelectrical actuator actuating a nozzle needle using hydraulic coupler. As a result of the pressure in the high-pressure channel, a coupler pressure is built up via the hydraulic coupler, the coupler pressure inducing a piezovoltage in the actuator. Because this voltage value is redundant with regard to the pressure value in the high-pressure channel, which is measured by a pressure sensor, the voltage value is used for monitoring the functioning of the pressure sensor. In the event of the failure of the pressure sensor, emergency operation is built up for the injector with the assistance of the induced voltage. The injector advantageously functions for injecting fuel in an internal combustion engine.

Dependencies are inferred from the claim text.