Ceramtec Gmbh

Ceramtec Ag, Innovative Ceramic Engineering

Festo Ag & Co

Ellenberger & Poensgen Gmbh

Reiner Bindig

Hans-Jürgen Schreiner

Alfons Kelnberger

Hans-Jurgen Schreiner

Jurgen Schmieder

Jürgen Schmidt

Matthias Simmerl

Peter Meckler

Michael Naumann

Markus Birner

Peter Stingl

Peter Post

Kurt Handschuh

Claudia Voigt

Günter Helke

J&uuml;rgen Gerhartz

Konrad Tzschentke

Hans-Juergen Schreiner

Thilo Steichele

Hans-J&uuml;rgen Schreiner

Gunther Helke

Jürgen Brandt

Andreas Gunther

Tobias Schmidt

Jürgen Schmieder

Andreas Günther

Günther Helke

A method, a device and use for measurement of a force with a pressure sensor made of a piezoelectric material. The change in the capacitance of the pressure sensor is used for force measurement so that no load amplifier is necessary for measurement and as a result the measuring system as a whole is miniaturized.

Pressure sensor for detecting force

According to the state of the art, piezoceramic multi-layer elements are sintered in air at temperatures of approximately 1100 DEG C or higher. Therefore, only a noble metal having a high melting temperature can be used as the inner electrode. Non-noble metals would oxidize. Therefore, a silver-palladium alloy having up to 40% palladium is normally used. However, such a measure is associated with high material costs. Lower melting temperatures of the inner electrode material, however, also require a ceramic material having correspondingly low sintering temperatures. The invention therefore proposes that an electrically non-conductive sintering additive added be added to the base material, and that the inner electrode comprise silver, preferably pure silver, as the main material component thereof, and an electrically non-conductive material component and/or a metal alloy or metal oxide mixture.

Piezoceramic multi-layer element

The invention relates to actuator module () having a piezoceramic multilayer actuator () arranged in a casing (). In order to avoid an increase in conductivity and hence rising leakage current at the actuator surface even after a long period of use, the invention proposes that the casing () is hermetically sealed, and a chamber () is arranged between the multilayer actuator () and the casing (), which chamber is entirely or partially filled with a medium () that chemically transforms and/or binds water.

Actuator module having a multi-layer actuator arranged in a housing and a continuously extremely low leakage current at the actuator surface

An electromagnetic relay, in particular a motor vehicle relay, contains a magnet yoke, a relay coil, a hinged armature which is pivotable about an axis of rotation and on which a moving contact, as working or switchover contact, is retained relative to at least one fixed contact. A piezo actuator is provided, which keeps the working or switchover contact closed when the relay coil is de-energized as a result of the actuation of the piezo actuator.

Electromagnetic relay

The invention relates to a force module () for generating forces in a highly dynamic manner by assembling a plurality of piezo actuators () for connecting to a voltage source. To enable the force module () to generate forces in the range of a few 100 kN in a highly dynamic and spatially resolved manner, according to the invention it is proposed that the force module () consists of at least two sub-modules (), each having at least two piezo actuators () and their electrical contacting elements, and a controlling and protection module () for the piezo actuators () in the sub-modules (), wherein all electric contacting elements of the sub-modules () are fed into the controlling and protection module ().

Force module with sub-modules and a controlling and protection module for generating forces in a highly dynamic manner

A monolithic multilayer actuator made of a sintered stack of thin films of piezoceramio with embedded metallic internal electrodes. All metallic internal electrodes of one polarity are electrically connected in parallel by way of a base metallization applied to the stack and wherein an external electrode is connected in an electrically conducting manner to the base metallization for electrical contacting purposes. In order to provide that the external electrode can be applied to the base metallization using simple and cost-effective means so that said electrode is expandable such that it dissipates the cracks arising from cracking energy in the actuator without the external electrode disconnecting in the process that are sintered together, the layer being applied onto the base metallization.

Monolithic multi-layered actuator with external electrodes made of a metallic, porous, expandable conductive layer

A device for generating electrical energy in a rotating system for the purpose of supplying electric current to electronic components in the system, comprising external forces, acting on the system, that act on piezoelectrically active energy converters in the system, as a result of which electrical energy is generated, and comprising an electronic system for processing the generated electrical energy and transferring it to the components.

Device for generating energy in a rotating system

A method for producing a component as monolithic multilayer element or multilayer bending element, comprising at least two layer stacks each having 1-400 layers of piezoelectrically active material which are separated by at least one layer stack comprising 0-100 layers of piezoelectrically inactive material, wherein the inner electrodes of the active layer stacks contain at least the following materials: a) pure silver b) electrically non-conductive material having a proportion by weight of 0% to at most 30% and the material of the piezoelectrically active layers has a sufficient activity in a thermal process such that sintering below the melting point of the material of the inner electrodes is possible and performed.

Monolithic bending element

A block of stacked green films provided with internal electrodes is laminated, at least one actuator is separated from the block, the actuator obtains its shape by means of a machining operation, is then sintered, and the sinter skin produced by the sintering is used as an insulating layer. The sinter skin is abraded at the points where the internal electrodes are connected to the external electrodes.

Process for the manufacture of piezoceramic multilayer actuators

The invention relates to a method for the manufacture of piezoelectric multilayer actuator in which thin layers of a piezoceramic material, called 'green leaves' on which at least one internal electrode is applied, are stacked to form a block such that the internal electrodes are guided in alternation to oppositely lying surfaces of the actuator, where they become bound together by an external electrode, the actuator compact being sintered and subjected to abrasive shaping, and then the base metallization is applied for the external electrode. In order to achieve insulation with a ceramic layer which can be applied after the sintering and the abrasive shaping, and thus satisfy even stringent requirements, it is proposed that areas to be insulated be coated by thick-layer methods with a paste consisting of an inorganic, low-sintering material or a mixture of materials and an organic binder system, and be then subjected to a burning-on process, the coating thickness after the sintering being between 1 and 40 &#x3bc;m, preferably between 2 and 20 &#x3bc;m, or between 4 and 15 &#x3bc;m.

Insulation for piezoceramic multilayer actuators

In piezoceramic multilayer actuators, the head region and the foot region consist of inactive, that is to say electrode-free, piezoceramic layers. Due to the arrangement of the metallic electrodes and the layers of the piezoceramic materials, the shrinkage of the piezoceramic material, in particular in the passive head region and foot region, is influenced during the sintering process and can cause the formation of cracks. Different expansion behavior of the active and of the passive region during operation also lead to stresses which favor crack formation, in particular at the boundary between both regions. According to the invention, it is therefore proposed that a transition region (), whose shrinkage and expansion behavior lies between the shrinkage and expansion behavior of the active region () and the shrinkage and expansion behavior of an inactive region () which are electrode free, adjoins the active region () up to the inactive head region () and up to the inactive foot region ().

Piezoceramic multilayer actuator with a transition region between the active region and the inactive head and foot regions

The invention relates to a monolithic multilayer actuator comprising a sintered stack of thin films, made from piezo-ceramic with inlaid metallic inner electrodes which extend from the stack on alternate sides and are electrically wired in parallel with external electrodes () and are provided with connector wires (). According to the invention, the actuator may be supplied with nominal voltage over a long period of time, without a change in the properties thereof, whereby the multilayer actuator () is sealed within a metallic or ceramic housing (), the connector wires () are integral parts of the housing base () and the housing () is filled with a water-absorbing medium () and a water-transporting, electrically-insulating medium ().

Monolithic multilayer actuator in a housing

Piezoceramic multilayer actuators and a process for their manufacture

A directly actuated electric valve is proposed that has a piezoelectric drive unit ( ) for direct actuation of a valve member ( ). The piezoelectric drive unit ( ) contains, extending transverse to the displacement direction of valve member ( ), at least one piezo-flexural element ( &prime;), which acts on valve member ( ) at one end and is mounted stationary with respect to the housing at the other, such that its electrically induced flexural motion produces the linear displacement motion of valve member ( ). Such a configuration permits very short switching times with compact dimensions.

Piezoelectric valve

A monolithic multi-layer actuator includes a sintered stack of thin films of piezoceramic material with metallic internal electrodes which lead out of the stack (,) in alternate directions and are connected electrically in parallel by way of external electrodes, with the external electrodes on the contact sides of the stack consisting of an applied basic metallisation and being connected to electrical connection elements preferably by way of soldering. In order to avoid failures of the actuator during dynamic loads it is suggested that an electroconductive electrode which is structured to be three-dimensional in structure be arranged between the basic metal lining and the connection elements, which electrode is connected to the basic metallisation by way of partial contact points and is constructed to be expandable between the contact points.

Growing community of inventors

Bindlach, Germany

Reiner Bindig