Piezoelectric actuator

US6940213B1 · kind B1 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Rudolf Heinz · Renningen, DE
• Friedrich Boecking · Stuttgart, DE

Key dates

• Filing date: Feb 24, 2000
• Grant date: Sep 6, 2005
• Expiry date: Feb 24, 2020

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02M63/0026
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a piezoelectric actuator, in particular for actuating control valves or injection valves of internal combustion engines in motor vehicles, having a circular, cylindrical piezoelectric actuator body 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 that function as electrodes, wherein these first and second electrode layers alternatingly contact a first and second electrically conductive common electrode connection. Either the piezoelectric actuator body has either an internal longitudinal bore and at least the first common electrode connection is provided on the inner wall of the actuator body constituted by the internal longitudinal bore and contacts every first electrode layer there or alternatively, the actuator body has no internal bore and the first and second electrode layers are respectively exposed on the outer cylinder wall of the actuator body at points angularly offset from one another and respectively contact the first and second electrode connections there.