Patent ID: 6940213
Filing Date: 2005-09-06
Classification: F02M,H01L

Abstract:
1. A piezoelectric actuator for actuating control valves or injection valves of internal combustion engines in motor vehicles, comprising a circular, cylindrical piezoelectric actuator body ( 1 ) in the form of a multilayered laminate made up of stacked layers of piezoelectric material with intervening metallic or electrically conductive, alternating first and second electrode layers ( 10 , 11 ) that function as electrodes, wherein these first and second electrode layers ( 10 , 11 ) alternatingly contact first and second electrically conductive common electrode connections ( 12 , 13 ), said first and second electrode layers ( 10 , 11 ) respectively include portions which are disposed only on the outer cylinder wall ( 4 ) of the actuator body ( 1 ), and at points that are angularly offset from one another, and each portion from each of the first and second electrode layers contacts the first and second electrode connections ( 12 , 13 ), wherein each first electrode layer ( 10 ) has a recess ( 17 ) which encompasses and insulates the second electrode connection ( 13 ), wherein each of the first and second electrode connections ( 12 , 13 ) constitutes a contact surface in the form of a section of a cylinder circumference extending at least 90° in the circumferential direction, and also extending in the longitudinal direction of the actuator body ( 1 ).