JPH0720930Y2 - Electrostrictive effect element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electrostrictive effect element used for a piezoelectric actuator, which includes a laminated body in which piezoelectric ceramic members and internal electrode conductors are alternately laminated.

[Conventional technology]

Recently, piezoelectric actuators have been regarded as extremely promising as optical or magnetic disk heads, various optical devices, precision positioning devices for precision machine tools, and other mechanical drive elements.

When using a laminated electrostrictive effect element for these devices,
Generally, a columnar electrostrictive effect element whose side surface is covered with resin or an electrostrictive effect element 1 having metal caps 3 and 11 on both ends is used as shown in FIG. The effect element 1 is assembled so as to be sandwiched by the actuator mounting members 12a and 12b.

[Problems to be solved by the device]

The above-mentioned conventional electrostrictive effect element was displaced in order to efficiently obtain a minute displacement of 1/1000 (10 μm for a total length of 10 mm) with respect to the total length of the electrostrictive effect element and to prevent cracking of the element. In order to evenly apply the load to both end faces of the element, the parallelism of both end faces of the electrostrictive effect element, the parallelism of the upper and lower metal caps, and the parallelism of the upper and lower mounting members are highly accurate. Therefore, there is a drawback that not only the cost of the electrostrictive effect element increases but also the cost increases significantly when it is used as an actuator.

[Means for Solving the Problems]

The electrostrictive effect element of the present invention is an electrostrictive effect element including a laminated body in which piezoelectric ceramic members and internal electrode conductors are alternately laminated.
Of the metal member, the first attachment member connected to the first metal member, the second metal member connected to the other end of the electrostrictive effect element, and the second metal member facing each other. And a second mounting member connected to a surface of the third metal member that does not face the second metal member, the second metal member, and the third metal member. It is characterized in that a transmission means is provided which is provided between the electrostrictive effect element and the metal member and transmits the displacement of the electrostrictive effect element to the first attachment member and the second attachment member without being biased.

[Action]

Since one end of the electrostrictive effect element is rotatably supported by the metal member via the steel ball, it is possible to mount the element in an optimal state regardless of the mounting member for mounting the element. it can.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of the electrostrictive effect element of the present invention.

The electrostrictive effect element 1 has a pair of lead wires 2a and 2b in which piezoelectric ceramic members and internal electrode conductor layers are alternately laminated. A metal cap 3 having a pair of lead terminals 4a and 4b made of glass terminals connected to the external electrode conductor of the electrostrictive effect element 1 and the lead wires 2a and 2b at one end of the electrostrictive effect element 1 and attached to the side surface by soldering. Are fixed on the inner bottom surface. Further, in the opening of the metal cap 3, a stainless bellows 5 having the same inner diameter as the outer diameter of the metal cap 3 and extending beyond the other end of the electrostrictive effect element 1 is welded over the entire circumference. There is. At the other end of the electrostrictive effect element 1, there is provided a conical recess 8a at the center of one surface and a recess 7 having an inner diameter substantially the same as the outer diameter of the electrostrictive effect element 1 at the center of the other surface. The metal member 6 is covered in the recess 7. Further, the metal member 9 having a conical concave portion 8b on one surface and having substantially the same size as the outer diameter of the metallic cap 3 is
facing the metal member 6 via the steel ball 10 sandwiched by a and 8b,
Moreover, it is welded to the bellows 5 over the entire circumference on the opening side of the bellows 5.

Next, a method for assembling the electrostrictive effect element according to the present embodiment will be described.

First, the lead wires 2a and 2b of the electrostrictive effect element 1 are connected to the lead terminals 4a and 4b of the metal cap 3 by soldering.
Then, the electrostrictive effect element 1 is put in the bellows 5 welded to the metal cap 3 and fixed with an adhesive so as to stand upright on the inner bottom surface of the metal cap 3. Next, the recess 7 of the metal member 6 is fitted into the upper end of the electrostrictive effect element 1 so that the steel ball 10 is sandwiched between the conical recess 8a of the metal member 6 and the conical recess 8b of the metal member 9. The metal plate 9 is fitted into the opening of the bellows 5. Finally, the metal member 9 and the bellows 5 are welded over the entire circumference to complete the assembly. The electrostrictive effect element completed in this way is attached to the actuator mounting members 12a, 12b.
Installed between them and applying voltage to the lead terminals 4a and 4b,
A desired displacement is generated in the direction in which the mounting portions 12a and 12b are expanded.

[Effect of device]

INDUSTRIAL APPLICABILITY As described above, the present invention has a rotatable structure composed of two metal members having steel balls sandwiched between both end faces of the electrostrictive effect element, so that both end faces of the electrostrictive effect element and the upper and lower metal members are formed. The end faces of the electrostrictive effect element and the mounting face of the mounting member can be brought into close contact with each other without finishing the parallelism between the end face of the member and both end faces of the mounting member and both end faces of the mounting member with particularly high precision. Therefore, there is an effect that the displacement can be obtained, and thus the manufacturing cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the electrostrictive effect element of the present invention,
FIG. 2 is a vertical sectional view of a conventional electrostrictive effect element. 1 ... Electrostrictive effect element, 2a, 2b ... Lead wire, 3 ... Metal cap, 4a, 4b ... Lead terminal, 5 ... Bellows, 6
... metal member, 7 ... recess of metal member 6, 8a ... conical recess of metal member 6, 8b ... conical recess of metal member 9 ... metal member, 10 ... steel ball, 12a, 12b ... Actuator mounting members.

Claims (3)

[Scope of utility model registration request] 1. An electrostrictive effect element including a laminate in which piezoelectric ceramic members and internal electrode conductors are alternately laminated, wherein a first metal member connected to one end of the electrostrictive effect element and the first A first mounting member connected to the metal member, a second metal member connected to the other end of the electrostrictive effect element, and a third metal member provided to face the second metal member.
And a second mounting member connected to a surface of the third metal member that does not face the second metal member,
A transmission means that is provided between the second metal member and the third metal member and that transmits the displacement of the electrostrictive effect element to the first mounting member and the second mounting member without being biased. An electrostrictive effect element characterized by being provided. 2. The second metal member has a first recess on a surface facing the third metal member, and the third metal member has a second recess on a portion facing the first recess. Has a recess of
The electrostrictive effect element according to claim (1), wherein the transmission means is a sphere provided between the first concave portion and the second concave portion. 3. The electrostrictive effect element according to claim (2), wherein the sphere is a steel ball.