JPS6138278A - Bimorph type piezo actuator - Google Patents

Abstract

PURPOSE:To minimize sliding parts by sealing a bimorph type piezo actuator in casings. CONSTITUTION:An electrical strain element 1 is formed as a board of bimorph type electrical strain elements. A bimorph type piezo actuator is comprised of the electrical strain element 1 and a voltage applying plate 13. Contact plates 17, 18 connected respectively with conductors 15, 16 are fixed in casings 3a, 3b, and the free ends of the contact plates 17, 18 are formed in curved shape to be pressed on the voltage applying plates 13, 14 owing to their elasticity when the casings 3a, 3b are fixed. An elastic plate 2 is bent by means of the bimorph type electrical strain element 1 when the voltage is applied to the voltage applying plate 13 or 14 to move a valve body 5 variably to either of positions for seating it at a valve seat 7 or 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention comprises a plate-shaped bimorph type electrostrictive element and a voltage application plate arranged at a predetermined interval on the bimorph type electrostrictive element,
The present invention relates to a bimorph piezoelectric actuator that applies a voltage to the applied voltage plate to cause strain in the bimorph electrostrictive element.

[Prior art and problems to be solved] Conventionally, electromagnetic valves have been widely used as switching valves that are switched by electrical control, but the movable core and the valve body that is switched and moved by the movable core are formed as sliding members. Because of this, there were problems in terms of durability and reliability of switching operation.

An object of the present invention is to provide a switching valve that eliminates as much of the sliding portion as possible, which is a problem in the prior art.

[Means to solve problems]

To achieve the above object, the present invention comprises a plate-shaped bimorph electrostrictive element and a voltage application plate arranged at a predetermined interval on the bimorph electrostriction element, and a voltage is applied to the voltage application plate to form the bimorph shape. A bimorph piezoelectric actuator that causes strain in an electrostrictive element includes a casing having a chamber therein for accommodating the actuator, and a connection plate attached to the casing and connecting a power source and the applied voltage plate, The casing is provided with a plurality of valve seats arranged at predetermined intervals and a plurality of flow paths associated with the valve seats, a valve body is provided at an end of the bimorph type electrostrictive element, and the valve body The valve seat and the valve body are positioned relative to each other such that the valve seat is seated on one valve seat when no voltage is applied to the applied voltage plate, and the valve seat is seated on the other valve seat due to distortion of the bimorph type electrostrictive element when voltage is applied. This was achieved using a bimorph type piezoelectric actuator that has the following characteristics.

〔effect〕

The present invention eliminates sliding parts and improves the durability and reliability of the switching valve. Furthermore, since it does not generate a back electromotive force unlike a solenoid in a solenoid valve, high-speed switching operation is possible, resulting in a switching valve suitable for high-frequency switching valves for digital actuators and high-speed sorting devices.

〔Example〕

The details of the present invention will be explained based on embodiments shown in the drawings.

In FIG. 1, an elastic plate 2 is fixed to an electrostrictive element 1. One end of the elastic plate 2 is clamped and fixed between a first casing 3a and a second casing 3b of two split casings 3 that can be fixed to each other. The electrostrictive element 1 and the elastic plate 2 are housed in a chamber 4 inside the casing 3.

A valve body 5 is fixed on both sides of the free end of the elastic plate 2, and one of the valve bodies 5 is connected to a first flow path 6 formed in the first casing 3a at the opening to the chamber 4. 1 facing the valve seat 7. The other side of the valve body 5 faces the second valve seat 9 provided at the opening to the second flow path 80 chamber 4 formed in the second casing 3b. The chamber 4 opens to the outside through a third flow path lO.

In the illustrated example, in a normal state in which the elastic plate 2 is fixed to the casing 3, the valve element 5 is seated on the second valve seat 9, closing the second flow path 8 and opening the first flow path 6.

Insulators 11 and 12 are fixed to the end of the electrostrictive element 1 opposite to the valve body 5 so as to sandwich them from both sides. In this case, the elastic plate 2 is also clamped between the insulators 11, 12. Two voltage application plates 13 and 14 are fixed with insulators 11 and 12 in between, and the voltage application plates 13 and 14 are arranged opposite to the electrostrictive element 1 at a predetermined interval.

An electrostrictive element in which a piezoelectric element that generates strain by applying an electric field and an elastic plate whose elongation rate is different from that of the piezoelectric element are bonded together is known as a bimorph electrostrictive element.

The electrostrictive element 1 is formed as a plate-shaped bimorph type electrostrictive element, and the electrostrictive element 1 and the applied voltage plate 13 form a bimorph type piezoelectric actuator.

Contact plates 17.18 connected to conductive wires 15.16 are fixed to the first casing 3a and the second casing 3b, respectively, and the free ends of the contact plates 17.18 are connected to the casings 3a, 3b.
It is curved so that it is elastically pressed against the voltage application plates 13 and 14 when the plate b is fixed.

By using the bimorph type electrostrictive element 1, the elastic plate 2 is caused to bend when voltage is applied to the voltage application plates 13 and 14,
The valve body 5 is switched between a position where it is seated on the first valve seat 7 and a position where it is seated on the second valve seat 9.

As the electrostrictive element, a combination of two types of materials is used: a material that is highly strained when an electric field is applied, and a material that is less strained. In this electrostrictive element, the electrostrictive element is bent due to the difference in strain when an electric field is applied. In the present invention, a bimorph type electrostrictive element in which an elastic plate 2 is laminated to the electrostrictive element 1 is used.

By pasting the electrostrictive element 1 and the elastic plate 2 together in this way, the elastic plate 2 is bent, and the valve body 5 is made movable between the first valve seat 7 and the second valve seat 9. It operates as an actuator.

According to the present invention, an actuator that functions as a 30,000-way switching valve or a 4-way switching valve can be obtained with a simple structure in which the so-called bimorph piezoelectric actuator is sealed in a casing. This actuator has no sliding parts, improving durability and reliability, and since there are no sliding parts, the force required to move the valve body is small, enabling energy savings and high-speed movement compared to conventional switching valves. It also made it possible.

The contact plates 17, 18 can also be embedded in advance when the casing 3 is molded with an insulating material. It is also possible for the contact plates 17, 18 to be formed by the conductor 15, 16 itself.

As shown in FIG. 2, the voltage application plates 13.14 are integrally molded to be embedded in the casings 3a, 3b, respectively, and the ends of the voltage application plates 13.14 are connected to tongue portions 17a forming outlet or terminal connection parts. , 17b may be formed to protrude outside the casing 3. In FIG. 2, it is not necessary to fix the applied voltage plates 13.14 through the insulating material 11.12, and the structure becomes simpler.

By fixing two actuators forming the switching valve shown in FIGS. 1 and 2 adjacent to each other as shown in FIG. 3, a five-way switching valve can be easily formed. Furthermore, a four-way switching valve can be formed by modifying the flow path. The switching mode can be changed depending on how the conductors 15 and 16 of the two switching valves are connected.

In FIG. 3, parts corresponding to those in FIG. 1 are given the same reference numerals. Since the structure and operation are the same as those shown in FIG. 1, detailed explanation will be omitted.

The embodiments shown in Figs. 1 to 3 are formed in a so-called povent valve type, and the valve body can approach and leave the valve seat surface, whereas the embodiment shown in Figs.
As shown in the figure, the valve body is formed as a kind of slide valve body, and has a plurality of flow passage openings 7.

It is formed so as to be slidable along the casing surface 19 having a radius 9' while maintaining a minute distance from the casing surface 19. Figure 4 (A) shows an example of a valve element for switching between two flow paths, and Figure 4 (B) shows an example of a valve element for switching between two or more flow paths. Also, at least 2 adjacent valve bodies 5
A recess 20 is formed to communicate between the individual flow paths.

In this example, no pressure is applied to the valve body in the direction of movement, so it has the advantage that it can be driven by a small element and can be provided with an arbitrary number of ports.

〔effect〕

According to the present invention, a switching valve without sliding parts can be obtained, which has excellent durability and
Improved reliability. Since there are no sliding parts, the force required to move the valve body is small, making it possible to save energy.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a bimorph actuator according to the present invention, FIG. 2 is a sectional view of a modification of FIG. 1, FIG. 3 is a sectional view of yet another modification, and FIG. 4 is another modification. A in the partial diagram of
B is a diagram of a valve that switches between two flow paths and B between a plurality of flow paths with one valve body. 1... Electrostrictive element 2... Elastic plate 3... Casing 4... Chamber 5... Valve body 6, 8', 10-... Channel 7.9... Valve seat 13 , 14... Applied voltage plate 1
5.16... Conductor wire 17.18... Contact plate 20.
... Written amendment to the recess procedure December 21, 1980 Director General of the Japan Patent Office Manabu Shiga 1, Indication of the case 1982 Patent Application No. 159326 2, Name switching valve of the invention 3, Person making the amendment Relationship with the case Patent applicant name: Konan Denki Co., Ltd. 4, agent address: 2-32-4-6 Nishi-Shinbashi, Minato-ku, Tokyo Title of the invention in the specification subject to amendment, scope of claims, detailed description of the invention, drawings A brief description of each column. 7. Contents of amendment +11 The name of the invention in the specification of the application is corrected to “Switching valve J.” (2) The description of the scope of claims in the specification of the application is corrected as shown in the attached sheet. (3) Specification No. 9 of the application The statement "Kotochini" in line 13 of the page has been corrected to "Toni". (4) In the specification of the present application, page 11, lines 2 to 5, the description "Bimorph......partial view" was replaced with "a vertical cross-sectional view of the switching valve. Figure 2 is the same as Figure 1. "Figure 3 is a vertical cross-sectional view of a modified example, Figure 3 is a vertical cross-sectional view of yet another modified example, and Figure 4 is a partial vertical cross-sectional view of another modified example." Attachment "2. Claims (11) Consisting of a plate-shaped bimorph electrostrictive element and a voltage application plate arranged at a predetermined interval on the bimorph electrostriction element, by applying a voltage to the voltage application plate, the bimorph A bimorph type piezoelectric actuator that causes strain in a type electrostrictive element), a casing having a chamber therein for accommodating the actuator, and a contact/discharge plate attached to the casing and connecting a power source and the applied voltage plate. , the casing is provided with a plurality of valve seats arranged at predetermined intervals and a plurality of flow paths associated with the valve seats, a valve body is provided at an end of the bimorph electrostrictive element, and the valve The relative positioning of the valve seat and the valve body is such that the body seats on one valve seat when no voltage is applied to the applied voltage plate, and seats on the other valve seat due to distortion of the bimorph electrostrictive element when voltage is applied. IIJL, which is characterized by
tL. (2) According to claim 1, the two valve seats are arranged opposite to each other at a predetermined interval in the switching movement direction of the valve body with the valve body in between to form a three-way valve. replacement light. ■Miniature light/light. ”

Claims (8)

[Claims] (1) Consists of a plate-shaped bimorph electrostrictive element and a voltage application plate arranged at a predetermined interval on the bimorph electrostriction element, and a voltage is applied to the voltage application plate to apply strain to the bimorph electrostriction element. The bimorph piezoelectric actuator that generates the piezoelectric actuator includes a casing having a chamber therein for accommodating the actuator, and a connection plate attached to the casing to connect a power source and the applied voltage plate, the casing having a predetermined interval. A plurality of valve seats and a plurality of flow paths associated with the valve seats are provided, and a valve body is provided at an end of the bimorph type electrostrictive element, and the valve body applies a voltage non-voltage to the applied voltage plate. A bimorph characterized in that the valve seat and the valve body are positioned relative to each other so that the valve seat is seated on one valve seat when voltage is applied, and the valve seat and the valve body are seated on the other valve seat due to distortion of the bimorph type electrostrictive element when voltage is applied. piezoelectric actuator. (2) The two valve seats are arranged opposite to each other at a predetermined interval in the switching movement direction of the valve body with the valve body in between, forming a two-way valve. bimorph type piezoelectric actuator. (3) A plurality of valve seats are formed side by side at predetermined intervals in the switching direction of the valve body, and open toward the valve body in a direction substantially perpendicular to the switching direction of the valve body to form a slide valve. The bimorph piezoelectric actuator according to claim 1, characterized in that: (4) Claim 3, characterized in that the valve body is formed with a recess that communicates the openings of two adjacent valve seats.
The bimorph type piezoelectric actuator described in . (5) The bimorph piezoelectric actuator according to any one of claims 1 to 4, wherein the contact plate is integrally pressed into a casing. (6) Any one of claims 1 to 5, characterized in that the voltage application plate is integrally embedded in the casing, and the end portion protrudes outside the casing as a tongue portion to form an outlet or a terminal connection portion. The bimorph piezoelectric actuator according to item 1. (7) The first aspect of the present invention is characterized in that the casing forms one unit when the actuator is incorporated therein, and two casings are fixedly arranged adjacent to each other to form a four-way valve. 7. The bimorph piezoelectric actuator according to any one of items 6 to 6. (8) Any one of claims 1 to 6, wherein the casing forms one unit with the actuator incorporated therein, and a plurality of casings are fixedly arranged adjacent to each other. The bimorph piezoelectric actuator according to item 1.