Patent ID: 6424078
Filing Date: 2002-07-23
Classification: F02M,H01L

Abstract:
A piezoelectric actuator for actuating control valves or injection valves of internal combustion engines in motor vehicles, having a piezoelectric actuator body (1) formed of a multi-layer laminate of stacked layers of piezoelectric material and between them electrically conductive layers acting as electrodes, in which the actuator body (1) is surrounded by a module wall (2), said module wall defines an intermediate chamber (10,11) therewithin, which chamber is divided into an upper chamber portion (11) and a lower chamber portion (10) by an axially movable partition (8) located transversely on an actuator head of said actuator body, and at least a selected one of the upper chamber (11) and the lower chamber (10) experiences a flow through it of a cooling air stream (L zu, L ab) for cooling the actuator body (1), the module wall (2) in the lower chamber portion (10) is provided with an air inlet opening (16) and an air outlet opening (17), and the actuator body, including its flow connections in the region of the lower chamber portion (10) through which air flows, is protected against moisture by an elastomer jacket (5, 15).