Siemens Aktiengesellschaft

Continental Automotive Gmbh

Kyocera Corporation

Harald Johannes Kastl

Carsten Schuh

Bernhard Döllgast

Masahiro Inagaki

Atsushi Ochi

Takami Sakamoto

Claus Zumstrull

Christoph Hamann

Christian Reichinger

Andreas Lenk

Maximilian H Kronberger

Katrin Benkert

Stefan Kohn

Stefan Denneler

Michael Denzler

Thomas Richter

Hermann Bödinger

A piezo-stack includes a plurality of lateral surfaces and a first passivation layer applied to a first lateral surface. The first passivation layer terminates flush with opposing lateral surfaces that adjoin the first lateral surface.

Piezo-stack with passivation, and a method for the passivation of a piezo-stack

A method for producing a piezo actuator includes: providing a green stack including alternately successive green films and inner electrode layers; forming trenches on the outside green stack in areas in which the inner electrode layers are intended to be electrically insulated from the corresponding outer electrodes, the trenches shortening the inner electrode layers from the outside of the green stack toward the inside; filling the trenches with an electrically insulating slurry; further processing the green stack, including filling the trenches with slurry, such that the green films produce piezo electric layers and the green stack produces a piezo stack; mounting two outer electrodes on the outside of the piezo stack, such that the two outer electrodes are alternately electrically connected to the inner electrode layers. The trenches may be filled with the slurry using one of the following methods; screen printing, immersion, spraying, or vacuum infiltration.

Method for producing a piezo actuator and piezo actuator

A piezoceramic multilayer actuator has a first sub-stack () with a plurality of piezoceramic layers () and at least one internal electrode (), the piezoceramic layers () and the at least one internal electrode () being laminated in an alternating manner, a second sub-stack () has a plurality of piezoceramic layers () and at least one internal electrode (), the piezoceramic layers () and the at least one internal electrode () being laminated in an alternating manner, and a connection layer () arranged between the first sub-stack () and the second sub-stack (), wherein the connection layer () is set up by a multitude of single connection points or connection lines () or other connection regions.

Piezoceramic multilayer actuator with high reliability

A piezoelectric component with a monolithic stack has piezoceramic layers and electrode layers arranged alternately one on top of the other, at least one porous security layer arranged in the stack for the formation of a crack if mechanical overload of the stack occurs, at least one outer electrode arranged at a lateral surface section for electric contacting of the electrode layers and a plastic sheath of the stack for protecting the stack, wherein the plastic sheath has silicon. The piezoelectric component is characterized in that a coating of the outer electrode, has silicon-free polymer, is arranged between the outer electrode and the plastic sheath. By coating the plating of the outer electrode, the area of the security layer present directly under the plating is protected from silicon component deposits. The piezoelectric component is used for the control of valves, particularly of injection valves of internal combustion engines.

Piezoelectric component comprising security layer and method for the production thereof

A piezoelectric component with a monolithic stack, has electrode layers and piezoceramic layers arranged alternately one on top of the other, the piezoceramic layers have a piezoceramic, and having at least one porous security layer arranged in the stack for the formation of a crack if mechanical overload of the stack should occur. The piezoelectric component has an infiltration barrier arranged between the security layer and a lateral surface section of the stack for suppressing the penetration of a foreign substance into the security layer. The piezoelectric component can be as a piezoactuator for controlling a valve, particularly a valve of an internal combustion engine.

Piezoelectric component comprising a security layer and an infiltration barrier and a method for the production thereof

A piezoelectric stack () has alternately successive piezoelectric layers () and inner electrode layers () which are alternately electrically connected to two outer electrodes () which are arranged on the outer side () of the piezoelectric stack (). The piezoelectric stack () also has at least one safety layer () which is arranged between two successive piezoelectric layers () instead of one of the inner electrode layers (). The safety layer () is structured in such a manner that it has an internal interruption () which is configured in such a manner that the safety layer () does not form an electrical contact between the two outer electrodes () if it contact-connects both outer electrodes () and is electrically conductive.

Piezoelectric stack and method for producing a piezoelectric stack

In a piezoelectric multilayer actuator () having micromechanical relief zones () and an insulation layer () as well as in a method for producing said actuator, as a result of the micromechanical relief zones (), poling cracks are concentrated in these relief regions (). This makes it possible to provide the sections I, II, III of the multilayer actuator () with an insulation layer () which only has an extension behavior similar to the multilayer actuator () without poling cracks.

Piezoceramic multilayer actuator with stress relief sections and insulation layers in sections without relief zones

A piezoceramic multilayer actuator () includes a plurality of green layers, wherein the green layers are to be converted to piezoceramic layers () with a piezoceramic material in a subsequent step of heating. A security layer material mixture with a second material () and particles () embedded in the second material () is provided, wherein the particles () have a third material different from the first material and different from the second material (). The security layer material mixture is laminated between two piezoceramic layers (), thereby forming a green stack. The green stack is heated to a sintering temperature, wherein the green layers are converted to the piezoceramic layers (), and wherein a chemical reaction of the third material degrades the mechanical connection of the piezoceramic layers () by the security layer ().

Piezoceramic multilayer actuator and method of manufacturing a piezoceramic multilayer actuator

A piezoceramic multilayer actuator () has a plurality of piezoceramic layers (), a security layer () and a plurality of inner electrodes (). The piezoceramic layers () has a piezoceramic first material sintered at a sintering temperature. The security layer () has a second material and is disposed between two piezoceramic layers (). Each of the plurality of inner electrodes () has a third material and is deposited between two piezoceramic layers (). The degree of sintering of the second material is lower than the degree of sintering of the third material.

Piezoceramic multilayer actuator manufactured according to particular sintering parameters and corresponding method of manufacturing

A piezoceramic multilayer actuator () has a plurality of piezoceramic layers () and a security layer () disposed between two piezoceramic layers (). The piezoceramic layers () have a piezoceramic first material sintered at a sintering temperature. The security layer () has a second material () and particles () at least partially embedded in the second material (). The particles () have a third material different from the first material and different from the second material (). An adhesion between the third material and the first material is weaker than an adhesion between the second material () and the first material.

A piezo actuator in a monolithic multilayer design, has at least one piezoelectrically active stack element, wherein the stack element has stacked piezoceramic layers made of piezoceramic material and electrode layers arranged between the piezoceramic layers, at least one piezoelectrically inactive terminating region arranged above the stack element, and at least one junction region arranged between the stack element and the terminating region, wherein the stack element, the terminating region and the junction region are connected to one another to form a monolithic total stack. The junction region has stacked piezoceramic layers and electrode layers arranged between the piezoceramic layers, and the piezoceramic layers and the electrode layers are in a form and are arranged on one another such that in the stack direction of the junction region one piezoelectrically active area per junction piezoceramic layer is successively changed from piezoceramic layer to piezoceramic layer.

Monolithic piezo actuator with a change in the electrode structure in the junction region, and use of the piezo actuator

A piezoactuator has at least one piezoelectric-active partial stack with piezoceramic layers arranged one over the other with piezoceramic material and electrode layers arranged between the piezoceramic layers, at least one piezoelectric-inactive terminating region arranged over the partial stack and at least one transition region between the partial stack and the terminating region, the partial stack, the terminating region and the transition region all connected together to give a monolithic complete stack. The transition region has a transition region stack with piezoceramic layers arranged one over the other and electrode layers arranged between the piezoceramic layers both have a form and are arranged on each other such that, in the stack direction of the transition region stack, from piezoceramic layer to piezoceramic layer there is a successive rotation about a main axis of the polarity and/or a rotation of the main axis of the electric control is provided.

Monolithic piezoactuator with rotation of the polarisation in the transition region and use of said piezoactuator

A piezoelectric component () has at least one monolithic piezo element () having an electrode layer (), at least one further electrode layer (), at least one piezoceramic layer () disposed between the electrode layers and at least one predetermined breaking point () which, in the event of mechanical overload of the piezo element, leads to the formation of a specific crack () in the monolithic piezo element, wherein the predetermined breaking point includes the electrode layer. The component is, for example, a piezoelectric actuator with a monolithic actuator body () in which piezo elements with predetermined breaking points and further piezo elements () without predetermined breaking points are arranged one on top of the other and sintered collectively.

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Fichtelberg, Germany

Harald Johannes Kastl