JPH0130393B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an actuator device that utilizes a piezoelectric effect and is applied to, for example, a relay or the like.

[Technical Background of the Invention and Problems Therewith] As is well known, actuator devices using piezoelectric elements have conventionally been considered to be of a laminated type in which a plurality of piezoelectric elements are stacked, or of a bimorph type. However, in all of these actuator devices, the movement of the piezoelectric element cannot be obtained sufficiently, so the movement of the piezoelectric element is mechanically expanded.
This magnification rate also has a limit, and the necessary and sufficient driving force for driving other devices cannot be obtained, which poses a practical problem.

[Purpose of the invention] This invention was made based on the above circumstances, and its purpose is to obtain a sufficient movable force using a piezoelectric element, and to be small, lightweight, and inexpensive. The present invention aims to provide a piezoelectric actuator device that is suitable for use in humans.

[Summary of the Invention] This invention provides, for example, a laminated piezoelectric element inside a sealed case filled with silicone oil, and a side surface of the case that has a smaller area than the piezoelectric element and a movable element on the outer surface. An action section is provided to magnify the action of the piezoelectric element using Pascal's principle and transmit it to the movable element.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a case where the present invention is applied to a relay. In the figure, a case 11 of a piezoelectric actuator 10 is made of a resin material with sufficient rigidity, and an incompressible liquid 12 such as silicone oil is contained inside the case 11.
is filled. Inside this case 11,
Electrodes 13 and 14 are arranged with a predetermined distance between them, and a plurality of rectangular piezoelectric films 15, for example, are laminated between the electrodes 13 and 14. The electrodes 13 and 14 have a piezoelectric film 15 having elasticity that allows them to move in accordance with the operation. Further, on one side of the case 11, an acting part 16 having a diameter _D1 , which is thinner than the wall thickness of the case 11, and curved to obtain elasticity is integrally provided with the case 11. A movable member 17 is provided in the central portion of the action portion 16 located on the outer surface side of the case 11. The tip of the movable element 17 is held at a position where the elasticity of the acting portion 16 and the pressure of the liquid 12 filled in the case 11 are balanced. Further, a movable contact piece 1 constituting a contact mechanism is provided at the tip of the movable element 17.
The free ends of the movable contact pieces 18 are brought into contact with each other, and the free ends of the movable contact pieces 18 are provided with contacts 19 . Further, a fixed contact piece 20 is provided near the movable contact piece 18, and this fixed contact piece 20 is provided with a contact point 21 that can come into contact with the contact point 19.

The operation in the above configuration will be explained. Said electrode 1
3 and 14, the movable element 17 is positioned in the state shown in FIG.
8. The contacts 19 and 21 on the fixed contact piece 20 are spaced apart from each other. In this state, the electrodes 13, 14
When a predetermined voltage is supplied to the piezoelectric film 15, the piezoelectric film 15 is expanded, and the force of the piezoelectric film 15
is uniformly propagated. Then, the force applied to the liquid 12 is propagated to the acting portion 16, and the acting portion 16 and the mover 17 are driven in a direction to protrude from the case 11. Therefore, the movable piece 18 is operated by the movable element 17, and this movable piece 18
The contact 19 of is contacted with the contact 21 of the fixed contact piece 20. The amount of movement of this mover 17 is determined by the amount of movement of the piezoelectric film 15.
and is inversely proportional to the surface area of the piezoelectric film 15 and the area of the acting portion 16.

On the other hand, when the voltage supply to the electrodes 13 and 14 is stopped from this state, the piezoelectric film 15 contracts, and the movable element 17 balances with the pressure of the liquid 12 due to the elasticity of the action portion 16 and the movable contact piece 18. returned to position. As a result, the movable contact piece 18
The contact 19 of is spaced apart from the contact 21 of the fixed contact piece 20.

According to the above embodiment, the piezoelectric film 15 is provided inside the case 11 filled with the incompressible liquid 12, and the force generated by the piezoelectric film 15 is applied to the liquid 12 and the acting portion having a smaller area than the piezoelectric film 15. It is transmitted to the movable element 17 via 16. Therefore, the force generated by the piezoelectric film 15 can be magnified and transmitted to the movable element 17. Furthermore, by changing the area ratio between the piezoelectric film 15 and the acting portion 16, it is possible to easily set a required magnification ratio, which is extremely convenient in practice.

Moreover, according to this configuration, the force generated by the piezoelectric film 15 is directly transmitted to the acting part 16 and the movable element 17 via the incompressible liquid 12.
Unlike the conventional bimorph type, there is almost no mechanical transmission loss, and the power transmission efficiency is good.

Furthermore, since the device can be made smaller than when the force of the piezoelectric film 15 is mechanically expanded, it is possible to make the shape and weight of the relay using this device smaller and lighter.

Furthermore, compared to mechanically expanding the force of the piezoelectric film 15, it is possible to set the moving distance of the movable element 17 with higher accuracy, so it is possible to construct a small and highly accurate relay. It is.

In the above embodiment, the present invention is applied to a relay, but the present invention is not limited to this. For example, as shown in FIG. When attached, the paper cone 22 vibrates in response to the signals supplied to the electrodes 13 and 14, and sound is generated, making it possible to configure a speaker.

Further, in the above embodiment, the action portion 16 and the mover 17
Although it is formed integrally with the case 11, it may be formed separately from the case 11, for example.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a piezoelectric actuator device that can obtain sufficient movable force using a piezoelectric element and can be small, lightweight, and inexpensive.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing one embodiment of a piezoelectric actuator device according to the present invention, and FIG. 2 is a side sectional view showing another embodiment of the invention. 11...Case, 12...Incompressible liquid, 1
3, 14... Electrode, 15... Piezoelectric film, 16
...Action part, 17... Movable element, 18... Movable contact piece, 20... Fixed contact piece, 22... Cone paper.

Claims (1)

[Scope of Claims] 1. A case filled with an incompressible liquid, a piezoelectric element housed inside the case, and a piezoelectric element provided on a side surface of the case so as to communicate with the inside of the case. A piezoelectric actuator device having a smaller area and comprising an operating portion that operates a driven member in response to the operation of the piezoelectric element. 2. The piezoelectric actuator device according to claim 1, wherein the acting portion is curved and integrally formed with the side surface of the case so as to have elasticity. 3. The piezoelectric actuator device according to claim 1, wherein the driven member is a movable contact piece that constitutes a switch mechanism. 4. The piezoelectric actuator device according to claim 1, wherein the driven member is a vibrating body constituting a speaker.