JPS63218115A - Piezo-electric relay - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a piezoelectric relay, and more particularly to a laminated piezoelectric driver relay with a simple structure.

[Conventional technology and problems]

Currently, the bimorph type and laminated type, which are commonly used as piezoelectric relays, each have advantages and disadvantages.

The bimorph type has the advantage of a large displacement magnification ratio because it obtains bending displacement by joining two piezoelectric thin plates, but it is difficult to obtain a displacement amount and a displacement force corresponding to the voltage.

Therefore, as seen in Japanese Utility Model Application Publication No. 59-110938, the application range of the piezoelectric bimorph is expanded using a mechanism in which an initial displacement is given to the piezoelectric bimorph and the mechanical bias is released during the operation process by voltage application. Although there are technologies to expand this, it has not yet been possible to obtain the amount of displacement and displacement force that corresponds to the voltage.

On the other hand, the laminated type generates pressure and displacement corresponding to the applied voltage, and the pressure is high (although it has the advantage of fast response speed, etc., but the displacement magnification rate is small, so it does not require complicated expansion). It has the disadvantage of requiring a mechanism.

In order to simplify this enlargement mechanism, for example,
There is a technique described in Japanese Patent No. 132670.

That is, in FIG. 4, the driver 3 is fixed to the upper part of the laminated piezoelectric driver 2 disposed on the substrate 1.
A lever 5 of a first hinge spring 4 whose one end is fixed to the substrate 1 comes into contact with the upper part of the lever 5, and a second hinge spring 6 provided at the free end side of the lever 5 has one end fixed to the substrate 1. Third
A fourth hinge spring 9 is attached to a lever 8 connected to the other end of the hinge spring 7, and a fourth hinge spring 9 is connected to the free end side of the lever 8.
The hinge spring 9 is attached to a lever 11 connected to a fifth hinge 10 fixed to the substrate 1, and a movable contact 12 is provided at the tip of the lever 11.

Furthermore, since the elongation strain of the laminated piezoelectric drive body depending on the voltage is mechanically expanded in several stages by the above-mentioned expansion mechanism, the complexity and size of the expansion mechanism are unavoidable. .

The complexity and size of the enlarging mechanism increases the mechanical strain generation location and inertial mass of the enlarging mechanism, which is a drawback to the responsiveness of the laminated piezoelectric drive body.

The present invention has been made to address these problems and provides a stacked piezoelectric relay that does not require a large displacement amplification mechanism.

[Means for solving problems]

The present invention provides a laminated piezoelectric drive body in which a plurality of piezoelectric elements are integrally laminated with electrodes of different poles alternately sandwiched between each other;
A piezoelectric device comprising: an output section having a pressure-sensitive conductor and two output terminals sandwiching the pressure-sensitive conductor; and a fixing member that overlaps and accommodates the laminated piezoelectric drive body and the output section and restrains their movement. A relay was configured such that the pressure-sensitive conductor was compressed in response to elongation strain in the lamination direction caused by voltage application to the laminated piezoelectric drive body.

[For production]

When a layered piezoelectric driver is applied, the layered piezoelectric driver stretches in the stacking direction and causes strain in response to the voltage.

Since both ends of the laminated piezoelectric drive body and the output section superimposed thereon are restrained by fixing members, the elongation strain of the laminated piezoelectric drive body becomes compressive strain of the pressure-sensitive conductor in the output section.

The electrical resistance of the pressure-sensitive conductor rapidly decreases in response to compressive strain, and the two output terminals sandwiching the pressure-sensitive conductor close, allowing current to flow.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the piezoelectric relay of the present invention, and reference numeral 2 denotes a laminated piezoelectric drive body in which electrodes of different poles are alternately sandwiched between a plurality of thin plate-like piezoelectric elements and are laminated integrally. , when a predetermined DC voltage is applied, a minute displacement occurs in the direction perpendicular to the layers (the stacking direction).

The electrodes sandwiched between the piezoelectric elements are each connected to an external electrode with the same polarity, and one external electrode is connected to the input terminal 1 via the electric wire 13.
4, and the other external electrode is connected to an input terminal 16 via an electric wire 15.

The output section 17 is superimposed on the upper surface of the laminated piezoelectric drive body 2 (see FIG. 2).

The output section 17 is composed of a pressure-sensitive conductor 18 and output terminals 19 and 20 in contact with both ends of the pressure-sensitive conductor 18, and the pressure-sensitive conductor 18 exhibits a rapid resistance change from an insulating state to a conductive state in response to pressure stimulation. Made from pressurized conductive rubber sheet material.

As for the internal structure of the rubber sheet material, for example, gold-plated metal particles are arranged in the thickness direction of the silicone rubber sheet, and electrodes are arranged at both ends of the rubber sheet in the thickness direction.

Therefore, by simply pressing the rubber sheet lightly in the thickness direction, a metal particle path is formed between the electrodes, as shown in Figure 3.
Even a slight deformation causes a large change in resistance.

Reference numeral 21 indicates a polymerized laminated piezoelectric drive body 2 and an output section 1
When the laminated piezoelectric drive body 2 receives a DC voltage and expands in one direction, the lower end side is prevented from expanding by the frame 21. Since it is restrained, the pressure-sensitive conductor 18 that extends only in the direction of the output terminal 20 (in the direction of the arrow 22) and is sandwiched between the output terminal 20 and the frame 21 is compressed.

Next, the operation of the piezoelectric relay configured as above will be explained.

When a human power signal is input to the input terminals 14 and 16, the stacking type piezoelectric drive body 2 expands in the direction of the arrow 22 and presses the output terminal 20.

Since the output terminal 0 is not fixed to the frame 21, its pressing force presses the pressure-sensitive conductor 18.

The pressure-sensitive conductor 18 has an output terminal 1 that abuts against the frame 21.
9 and the output terminal 20 is pressed.

In the pressure-sensitive conductor 18, when no pressure is applied, the metal particles arranged in the thickness direction in the silicone rubber are spaced apart, and the resistance between the electrodes is high and the pressure-sensitive conductor 18 exhibits insulating properties, but when the pressure increases, the silicon rubber When the rubber is compressed, the metal particles become conductors, exhibiting electrical conductivity.

Therefore, as shown in FIG. 3, the resistance value rapidly decreases due to slight deformation, and the output terminals 19 and 20 are connected.

Furthermore, when the human power signal is turned off, the laminated piezoelectric drive body 2 is reduced to its original shape, so the pressure-sensitive conductor 18 also returns to its no-load state and the connection between the output terminals 19 and 20 is released.

Therefore, a complicated and large mechanical expansion mechanism is no longer necessary, and a compact piezoelectric relay that is resistant to vibration and shock can now be obtained.

〔effect〕

The present invention has the following effects.

(a) A complicated and large mechanical expansion mechanism, which has been a drawback of conventional laminated piezoelectric relays, is no longer required, and the volume of the piezoelectric relay becomes compact.

(3) The piezoelectric relay has a simple structure, and the pressure-sensitive conductor is resistant to vibrations and shocks, making it more durable than mechanical expansion mechanisms, making the piezoelectric relay more reliable.

(C) Furthermore, since the piezoelectric relay of the present invention can have an entirely sealed structure, its uses are expanded.

(d) Extremely responsive because there is no inertial mass like mechanical expansion mechanisms.

[Brief explanation of the drawing]

Figures 1 to 3 show embodiments of the present invention, with Figure 1 being a longitudinal cross-sectional view of a piezoelectric relay, Figure 2 being a perspective view of the internal components of the piezoelectric relay, and Figure 3 being a view of a pressure-sensitive conductor. A characteristic curve diagram showing the relationship between deformation and resistance value. FIG. 4 is a perspective view of a conventional laminated piezoelectric relay. 2... Laminated piezoelectric drive body, 13.15... Electric wire, 1
4.16...Input terminal, 17...Output section, 18...
・Pressure-sensitive conductor, 19.20...output terminal, 21...
flame. Patent applicant: Yazaki Sogyo Co., Ltd. Figure 1 @ Figure 2

Claims (1)

[Claims] An output having a laminated piezoelectric drive body integrally laminated with electrodes of different polarities alternately sandwiched between each of a plurality of piezoelectric elements, a pressure-sensitive conductor, and an output terminal sandwiching the pressure-sensitive conductor. and a fixing member that accommodates the laminated piezoelectric drive body and the output part in a superimposed manner and restrains the movement of both ends thereof, and the laminated piezoelectric drive body is free from elongation strain in the lamination direction caused by the application of voltage. A piezoelectric relay characterized in that conduction of the output terminal is obtained by compressing the pressure-sensitive conductor in response to the pressure-sensitive conductor.