Hoerbiger Ventilwerke Aktiengesellschaft

Hygrama Ag

Enfo Grundlagen Forschungs Ag

Hoechst Ceramtec Aktiengesellschaft

Hoerbiger Fluidtechnik Kg

Hoerbiger Ventilwerke Aktiengessellschaft

Hoerbigee Ventilwerke Aktiengesellschaft

Herbert Frisch

Johannes Wirtl

Roland Zengerle

Thomas Uhl

Microvalve

A pneumatic actuating arrangement with a plurality of consumers (1) having working areas (7,8), a plurality of feed air/signal distributors (13) connected to a common pressure source and a common control unit (19), a plurality of electrically-actuated switching devices respectively arranged directly at the consumers (1) forming separate consumer units (9), and a combination line (12) extending between each consumer unit (9) and a feed air/signal distributor (13), each combination line including a supply pressure line for supplying air to the working areas of a respective consumer and electrical signal lines for connecting the electrically-actuated switching devices of a respective consumer unit to said common control unit.

Pneumatic actuating arrangement

A sealing ring (10) includes an outer sealing region (11) with a sealing edge (18) which rests in the installed state against the surface region to be sealed, and a holder region (12) which is situated within the sealing region (11). To prevent or render the pulling out of the sealing ring (10) from the corresponding groove-shaped recess (13) more difficult, the groove-shaped recess (13) includes at least one offset holding shoulder (16), and the holding region of the sealing ring (10) includes at least one corresponding holding edge (17), which in the installed state of the sealing ring (10) holds the sealing ring shape-lockingly like a barb.

Sealing arrangement

For a piezo valve (1) the sealable surface of the seat (13) of the controllable medium connection is so large that the pressure-induced closing force of the sealing region (14) of the bending element (4) that is generated in accordance with the medium pressure acting in the second switch position is greater than the elastically induced counterforce and smaller than the total of this counterforce and the piezo reset force acting upon application of a corresponding control voltage. Thus, both switch positions of the valve can also be held for a long period of time following pulsed voltage operation without any additional voltage application.

Piezo valve

In order to balance out the effects of the electrical and mechanical relaxation of a piezo-electric bending element which has a control area that moves in response to an applied control voltage against an elastically applied counterforce, the counterforce is applied by way of a separate external loading system. In addition, the bending element can be pre-tensioned elastically against the action of the counterforce by means of a clamped end.

A piezoelectric bending transducer is described which is suitable for installation in a valve channel. It is composed of at least one ceramic layer which is metalized on both sides and has piezoelectric properties and which is polarized such that on application of a voltage it undergoes a change in length, and of at least one rigid molding which is joined to the whole surface thereof and has approximately the same surface dimensions and which on application of a voltage does not undergo an elongation or undergoes an opposite elongation. The piezoceramic layer contains an unmetallized area which has a roughness R.sub.a of less the 0.5 .mu.m and covers an orifice in the valve channel.

Piezoelectric bending transducer and the use thereof

In order to be able to manage with minimum switching force, one of the respective sealing regions on the switching member or valve body of a two-position seat valve is made in the form of a circular sharp edge of small cross-sectional edge radius, thus requiring only a very small force for keeping the valve tight. In particular, in combination with a pressure equalizing construction, this enables very low control energy to undergo maximum amplification.

Two position seat valve

An electro-pneumatic signal converter is provided with a piezo-electric bending element (3) disposed in a sealed transmitter casing (1) from which a signal output (4) issues. It controls a pneumatic signal transmitter which consists of an air inlet seating (5) and an air outlet seating (6) provided opposite each other in the transmitter casing (1). The piezo-electric bending element (3) is pretensioned against the air inlet seating (5) by a spring. In order to improve its retention and guiding, the piezo-electric bending element (3) is disposed in a chamber (2) which closely surrounds it in the transmitter casing (1), in which support zones (14, 16) spaced-apart in the axial direction are provided for the bending element (3), and in addition the piezo-electric bending element (3) is retained and urged against the support zones (14, 16) by a guide spring (7) fixed in the transmitter casing (1).

Electro-pneumatic signal converter

An electro-pneumatic signal converter, having a piezo-electric bending element (1) which bends when an electrical voltage is applied and controls a pneumatic signal transmitter. The piezo-electric bending element (1) is securely clamped in a sealed transmitter casing (4) and controls an air inlet seating (7) and an air outlet seating (8) which are inserted opposite one another in the transmitter casing (4). In the absence of electrical voltage the piezo-electric bending element (1) bears against the air inlet seating (7), against which it is pretensioned. When a voltage is applied, it separates from the air inlet seating (7) and closes the air outlet seating (8). The respective pneumatic signal is taken off on a signal output (10) which is led out of the sealed space (9) of the transmitter casing.

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Vienna, Austria

Herbert Frisch