Method and apparatus for überprüfug a piezoelectric actuator

摘要

A piezoelectric actuator (2) according to the present invention is a fuel injection device (i) in the installed. The piezoelectric actuating device opens or closes an injection opening of the fuel injection device in a controlled manner. The piezoelectric actuating device (2) comprises a piezoelectric element (210), which in a cylindrical housing (200) is arranged, and a movable element (260), in the case of a bottom end of the housing is arranged. A gap (gp) is between the movable element (260) and the piezoelectric element (210) is formed. A pitch or a gradient (δgrad) of the movable element (260) in relation to the piezoelectric element (210), on the basis of a smallest gap (a) in the case of an edge region of the movable element and a central gap (b) in the case of the central axis is detected. The smallest gap (a), on the basis of a piezoelectric voltage (vp) is measured, in the piezoelectric element (210) on the basis of a contact of the movable element (260) with the piezoelectric element (210) is produced, and the central gap (b), on the basis of a biasing force (f) of the movable element (260) against the piezoelectric element (210) is measured.