JPH05226716A - Simply packaged electrostrictive effect element - Google Patents

Abstract

PURPOSE:To get elements different in request properties at low cost, in a simply packaged electrostrictive effect element which has an upper metal fitting at the top of the electrostrictive effect element surrounded by a metallic case and a lower metal fitting at the bottom. CONSTITUTION:A simply packaged electrostrictive effect element simple 6 has, at the upper metal fitting 2, a conical projection as an engaging means, and has, at the lower metal fitting 3, a conical recess, the area of the bottom of which is equal to the area of the bottom of the projection and the depth of which is larger than the height of the projection, as an engaging means, and two pieces of simple electrostrictive effect elements are coupled by this engaging means. Hereby, it will do to change the number of simply packaged electrostrictive element simples to be coupled, according to request property, so the necessity of completing a number of members different in design vanishes, and further the production line is simplified, and the cost is cut down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostrictive effect element, and more particularly to a case-type simple exterior electrostrictive effect element.

[0002]

2. Description of the Related Art In a conventional electrostrictive effect element, as shown in FIG. 3, an electrostrictive material 7 having a thickness of about 0.1 mm and an internal electrode 8 having a thickness of about 10 μm are alternately laminated. On the exposed pair of side surfaces, the end faces of the internal electrodes 8 are alternately arranged and alternately insulated on each side by an insulating layer 9 such as glass, and the non-insulated internal electrodes are formed on each side by silver paste or the like. The external electrodes 10 are electrically connected. At this time, solder 12 is applied to each external electrode 10.
When a voltage of 150 V is applied to the lead wire 5 connected by, a displacement of about 20 μm is generated in the electrostrictive effect element having a length of 20 mm.

Normally, the electrostrictive effect element is coated with epoxy resin 11 except for both upper and lower end surfaces so that the end surfaces of the external electrode 10, the insulating layer 9 and the internal electrode 8 do not come into direct contact with the outside air. This electrostrictive effect element has a structure in which the internal electrodes 8 are exposed at intervals of 0.1 mm on the side surface, and a high voltage of 150 V is applied between the internal electrodes 8, so that water or an ionic substance is attached. This is to prevent the drawback that the insulating property is deteriorated by doing so.

However, it is difficult to completely prevent invasion of moisture and contaminants with the epoxy resin 11, and it can be said that the reliability has been significantly improved (about one digit) compared with the initial development of the electrostrictive effect element. However, the electrostrictive effect element of this structure has a drawback that the reliability is still low as compared with general electronic components.

As one method for improving the drawbacks of such a resin-coated electrostrictive effect element, a completely airtight metal case-encased electrostrictive effect element for completely shielding the outside air was devised as shown in FIG. (See Japanese Patent Laid-Open No. 2-125674). In this electrostrictive effect element with a completely airtight metal case, a metal member 14 having an airtight lead terminal 16 is fixed to one of both end faces of the electrostrictive effect element 1 which is covered with an epoxy resin and inserted in a metal bellows case. On the other hand, a metal member 15 is fixed to the other, and the bellows case and the metal member 14 and the metal member 15 are connected by welding or the like to form a sealed structure.

With this structure, the reliability is greatly improved, but on the other hand, the outer shape is significantly larger than that of the resin-clad electrostrictive effect element. Also, there is a drawback that the cost is significantly increased due to the complicated and elaborate assembly process for the case.

As a method for improving the respective drawbacks of the resin-clad type element and the completely airtight metal case encased electrostrictive element, a simple external type electrostrictive element as shown in FIGS. 5 (a) and 5 (b) is used. Is proposed. Note that FIG.
FIG. 5A is a vertical cross-sectional view, and FIG. 5B is a plan view (not disclosed at the time of filing of the present application for Japanese Patent Application No. 3-102292).

The simple exterior type electrostrictive effect element of this structure has the following structure. A disk-shaped conical upper metal fitting having a cone having a height of about 3 mm and a bottom diameter of about 6 mm at one end surface of the electrostrictive effect element 1 inserted in a cylindrical stainless steel metal case 4. 2 is adhered with an adhesive, and the other surface has a disc-shaped stainless steel plate having a thickness of about 5 mm and has lead holes 3a through which the lead wires 5 pass, and a depth of about 2 mm.
The lower metal fitting 3 having a conical recess is adhered with an adhesive, and the lower metal fitting 3 and the metal case 4 are fixed by spot welding.

At this time, the upper metal fitting 2 can slide by using the inner surface of the metal case 4 as a guide to transmit the displacement of the electrostrictive effect element 1 to another object.

The simple exterior type electrostrictive effect element of this structure has the following features with respect to the resin exterior type electrostrictive effect element.

It is not easily affected by the atmosphere and has high reliability. This effect is further improved by sealing the lid member and the case with a sealing material having elasticity.

The accuracy of the external dimensions is improved.

Strong against external force, especially with anti-aggregation force.

It is easy to join with other members.

It has a conical projection and a hollow,
Easy to align.

On the other hand, the electrostrictive effect element in the completely airtight metal case has the following features.

The external dimensions are small.

Since the manufacturing process is simple, it is possible to significantly reduce the cost.

[0019]

The displacement amount of the conventional simple exterior electrostrictive effect element described above is determined by the element length of the internal electrostrictive effect element. As described above, when the internal electrostrictive effect element has a length of 20 mm and a voltage of 150 V is applied, it is about 2
Although the displacement amount of μm can be obtained, the maximum displacement amount required for various purposes varies. For example, 20μm, 40μ
m, 60 μm, 120 μm, etc., where the internal element lengths are 20 mm, 40 mm, 60, respectively.
The design must be mm and 120 mm. That is, it is necessary to prepare simple exterior type electrostrictive effect elements having different length designs depending on applications, and as a result, various kinds of members must be prepared, and the production line becomes complicated and the cost becomes high. is there.

An object of the present invention is to provide a simple exterior type electrostrictive effect element capable of manufacturing an electrostrictive effect element having various characteristics required at low cost.

[0021]

According to the present invention, there is provided an electrostrictive element inserted in a cylindrical metal case, and is attached to one end of the electrostrictive element so as to slide on the inner surface of the metal case. In a simple exterior electrostrictive effect element having a first lid member and a second lid member bonded to the other end of the electrostrictive element and fixed to the inner surface of the metal case, the first and second The lid member has a fitting means for fitting and adhering the first and second lid parts, and the metal case is for taking out a lead wire from the electrostrictive element provided on a side surface thereof. Is characterized by having lead holes.

Further, the present invention is characterized in that the simple exterior type electrostrictive element is a single body and includes two or more simple exterior type electrostrictive effect elements which are coupled by a fitting means.

According to the present invention, the fitting means includes a conical projection provided on an upper surface of the first lid member, and a bottom area and a depth provided on a lower surface of the second lid member. Is preferably a conical depression equal to or larger than the bottom area and height of the protrusion.

Further, according to the present invention, the fitting means includes a truncated cone-shaped projection provided on an upper surface of the first lid member, and a bottom area and a height thereof provided on a lower surface of the second lid member. Is preferably a truncated cone-shaped recess equal to or larger than the bottom area and height of the protrusion.

[0025]

The upper and lower lid members that seal the electrostrictive effect element with the metal case have, for example, a conical projection for the upper lid member and a projection for fitting the lower lid member with the projection. Grooves of equal or larger size are provided as fitting means. A plurality of the simple exterior electrostrictive elements are connected by the fitting means according to the required displacement amount.

Therefore, it is not necessary to prepare a large number of members having different designs, and the production line can be simplified, thereby making it possible to significantly reduce the cost.

Further, as the fitting means, when the electrostrictive effect element has a cylindrical shape, a conical shape or a truncated cone shape is preferable. The fitting means is not limited to this, and may have another shape according to the shape of the electrostrictive effect element.

[0028]

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

FIG. 1A is a vertical sectional view showing a first embodiment of the present invention, and FIG. 1B is a plan view thereof.

The first embodiment includes two simple exterior type electrostrictive effect element single bodies 6, and a simple exterior type electrostrictive effect element single body 6 is provided.
Is about 1.5 mm in height at the tip of the upper end of the electrostrictive effect element 1 inserted in the cylindrical metal case 4 made of stainless steel,
A disc-shaped upper metal fitting 2 having a cone with a bottom surface diameter of 5.0 ± 0.01 mm is adhered with an adhesive, and a depth of about 1.
The lower metal fitting 3 having a conical recess having a diameter of 7 mm and a diameter of 5.0 ± 0.01 mm is adhered with an adhesive, the lower metal fitting 3 and the metal case 4 are fixed by spot welding, and the lead wire 5 is connected to the metal case 4. It is configured to be taken out from the side surface of the via the lead hole 4a.

In this embodiment, the lower metal fitting 3 of the upper simple exterior type electrostrictive effect element single body 6 and the upper metal fitting 2 of the lower simple exterior type electrostrictive effect element single body 6 are fitted to each other with an adhesive. Bonded to form a simple resin exterior device. The lead wire 5 taken out from the side surface of the metal case 4 is obtained by soldering and connecting the positive electrodes to each other and the negative electrodes to each other. Further, the lead hole 4a is sealed with a sealing material having elasticity.

A feature of the present invention is that, in FIG. 1, the simple exterior electrostrictive effect element single body 6 is a top metal member 2 as a first lid member.
Has a conical projection as a fitting means, and the lower metal fitting 3 as a second lid member as a fitting means has a conical recess whose bottom area is equal to the bottom area of the projection and whose depth is larger than the height of the projection. And each metal case 4 has a lead hole 4
a is provided and these two simple exterior type electrostrictive effect element single bodies 6 are connected by the fitting means.

Next, the electrostrictive characteristics obtained in this embodiment will be described. The simple exterior type electrostrictive effect element alone 6 is 15
A displacement amount of 20 μm was obtained by applying 0 V, but in the present example in which two pieces were connected, a displacement amount of 40 μm was obtained at 150 V.

In the first embodiment, the case where two pieces are connected has been described, but it is naturally possible to connect three or more pieces, and in actuality, 30 simple exterior electrostrictive effect element units 6 are connected to each other to make about 6 pieces.
It was confirmed that a displacement amount of 00 μm was obtained.

FIG. 2 (a) is a vertical sectional view showing a second embodiment of the present invention, and FIG. 2 (b) is a plan view thereof.

In the second embodiment, the fitting means for the upper fitting 2 and the lower fitting 3 in the first embodiment shown in FIG. 1 is changed from a conical shape to a truncated cone shape. That is, upper metal fitting 2
Has a frustoconical projection having a height of 1.0 mm, an upper circumference of 2.0 mm, and a bottom circumference of 5.0 ± 0.01 mm. On the other hand, the lower metal fitting 3 has a conical first-shaped recess having a height of 1.5 mm, an upper circumference of 1.0 mm, and a bottom circumference of 5.0 ± 0 mm. The second embodiment is similar to the first embodiment in that two simple exterior electrostrictive effect element single bodies 6 are connected, and the same electrostrictive characteristics as the first embodiment can be obtained.

Also in the second embodiment, as in the first embodiment, two or more simple exterior electrostrictive effect element units 6 can be connected.

[0038]

As described above, the present invention has a structure in which two or more simple exterior type electrostrictive effect elements can be connected by the number capable of obtaining a desired displacement amount, so that many members having different designs are prepared. There is no need, and the production line can be simplified, resulting in significant cost reduction.

[Brief description of drawings]

FIG. 1 is a vertical sectional view and a plan view showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view and a plan view showing a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing an example of a conventional resin-coated electrostrictive effect element.

FIG. 4 is a vertical cross-sectional view showing an example of a conventional electrostrictive effect element with a completely airtight metal case.

FIG. 5 is a vertical sectional view and a plan view showing an example of a conventional simple exterior electrostrictive effect element.

[Explanation of symbols]

 1 Electrostrictive effect element 2 Upper metal fitting 3 Lower metal fitting 3a, 4a Lead hole 4 Metal case 5 Lead wire 6 Simple exterior type electrostrictive effect element single body 7 Electrostrictive material 8 Inner electrode 9 Insulating layer 10 External electrode 11 Epoxy resin 12 Solder 13 Bellows 14, 15 Metal member 16 Airtight lead terminal

Claims (4)

[Claims] 1. An electrostrictive element inserted into a cylindrical metal case, a first lid member adhered to one end of the electrostrictive element and provided so as to slide on an inner surface of the metal case, In a simple exterior electrostrictive effect element having a second lid member adhered to the other end of the electrostrictive element and fixed to the inner surface of the metal case, the first and second lid members are the first and the second lid members. It has a fitting means for fitting and adhering the second lid portion, and the metal case has a lead hole for taking out a lead wire from the electrostrictive element provided on a side surface thereof. A simple exterior electrostrictive effect element. 2. The simple exterior electrostrictive effect element according to claim 1, wherein the simple exterior electrostrictive element is a single body, and two or more simple exterior electrostrictive effect elements are joined by a fitting means. A simple exterior type electrostrictive effect element including: 3. The fitting means comprises a conical projection provided on the upper surface of the first lid member, and a bottom area and depth of the projection provided on the lower surface of the second lid member. The simple exterior electrostrictive effect element according to claim 1 or 2, which is a conical recess that is equal to or larger than the bottom area and height. 4. The fitting means is a truncated cone-shaped projection provided on the upper surface of the first lid member, and the bottom surface and height of the projection are provided on the lower surface of the second lid member. The simple exterior type electrostrictive effect element according to claim 1 or 2, wherein the simple exterior electrostrictive effect element is a truncated cone-shaped recess that is equal to or larger than the bottom area and height of the.