Piezoelectric actuator

US7429813B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gerhard Walter · Hamburg, DE
• Armin Mann · Sachsenheim, DE

Key dates

• Filing date: Nov 18, 2004
• Grant date: Sep 30, 2008
• Expiry date: Apr 26, 2025

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N30/88

Abstract

Piezoelectric actuators having ceramic layers and electrode layers, and being provided with an outer cover layer on each end face of the piezoelectric actuator. The ceramic layers and the outer cover layers each have a predetermined dielectric constant. Rapid switching of the actuator results in considerable electromagnetic interference, which must be reduced through complex measures involving the control unit or electric lines. The device reduces electromagnetic interference by decreasing the interfering capacitance between the actuator and the actuator housing connected to ground electrically. The outer cover layers have a lower relative dielectric constant than the ceramic layers between the outer cover layers.