JP2658596B2 - Electrostrictive effect element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostrictive element utilizing an electrostrictive effect, and more particularly to an outer case structure.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a cylindrical case 3a, 3b is bonded to the upper and lower end surfaces of a laminated body 1 with adhesives 7a, 7b, and a lead is connected to the cylindrical case 3b. Terminals 5a and 5b are provided, and electrically connected to the laminated body 1 by lead wires 2a and 2b.
b, a cylindrical metal bellows 9 that expands and contracts in the polarization direction of the laminate is welded.

[0003]

The above-described conventional electrostrictive effect element requires an environment,
In particular, it is easily affected by moisture, and it is important for reliability to prevent moisture from entering.

However, the conventional electrostrictive effect element uses a metal bellows 9 having a spring property utilizing elastic deformation of a metal, as shown in FIG. There is a defect that the airtightness is lost due to breakage, and the high-speed response is deteriorated due to resonance of the bellows.

SUMMARY OF THE INVENTION It is an object of the present invention to stably maintain a sealed state for a long period of time, not to cause breakage due to metal fatigue, and to degrade high-speed response without resonating like a bellows. An object of the present invention is to provide an electrostrictive effect element which does not cause the electrostrictive effect element.

[0006]

An electrostrictive effect element according to the present invention is an electrostrictive effect element in which plate-like electrostrictive ceramic members and internal electrode conductors are alternately laminated, and is fixed to a first end face of the laminate. A first cylindrical case, and a second cylindrical case fixed to the second end surface, where the first cylindrical case and the second cylindrical case face each other. Wherein the first cylindrical case and the magnet are fixed, the second cylindrical case and the magnet or a member made of a high magnetic permeability material are fixed, and the magnet fixed to the first cylindrical case and the magnet are fixed. Second
A magnetic fluid is provided in a gap between the magnet and a member made of a material having high magnetic permeability fixed to the cylindrical case.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of one embodiment of the present invention. As shown in FIG. 3, the laminate 1 is prepared by mixing zirconate titanate or lead titanate-based electrostrictive ceramic powder, a binder, and an organic solvent, slip-casting into a sheet shape, and drying silver / palladium on a dried green sheet. A conductor paste in which the mixed powder is dispersed in a vehicle is screen-printed, and a plurality of internal electrodes are laminated, laminated by hot pressing, then debindered and sintered to form an electrostrictive ceramic member 10.
And the internal electrode body 11a are alternately laminated.

As shown in FIG. 3, the lead wires 2a and 2b alternately connect the internal electrode conductors 11a of the laminate 1 alternately.
It is connected to a pair of comb-shaped external electrode conductors 11b.

Donut-shaped magnets 4a, 4b are fixed to the cylindrical cases 3a, 3b, and lead terminals 5a, 5b are provided on the side surfaces of the cylindrical case 3b. The lead terminals 5a and 5b are electrically connected to external electrodes of the laminate by the lead wires 2a and 2b.

The laminate 1 is bonded to the cylindrical cases 3a, 3b with adhesives 7a, 7b. The clearance between the magnets 4a and 4b is about 0.3 mm. Into this gap, a magnetic fluid 8 in which a magnetic powder of about 10 mm in which a surfactant is adsorbed is dispersed in a silicone-based oil or a fluorine-based oil is injected. The injection of the magnetic fluid 8 is performed in nitrogen whose dew point has been lowered to −30 ° C. after vacuum drying the whole.

FIG. 2 is a longitudinal sectional view of another embodiment of the present invention. In this embodiment, instead of the magnet 4b, a high permeability material 6 made of armco iron (permeability of 10 × 10 ₋₁₃ H / m) is used.

FIG. 5 is a diagram showing the high-speed response of the conventional example and the embodiment of the present invention. It can be seen that the displacement amount is not easily stabilized in the conventional example of the diagram (a), whereas the embodiment of the diagram (b) is immediately stable.

[0013]

As described above, according to the present invention, a sealed state can be stably maintained for a long period of time by sealing with a magnetic fluid. In addition, since elastic deformation is not used, no destruction due to metal fatigue occurs, and resonance does not occur unlike bellows, so that high-speed response does not deteriorate.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of an electrostrictive effect element according to another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a laminate.

FIG. 4 is a longitudinal sectional view of an example of a conventional electrostrictive effect element.

FIG. 5 is a diagram showing a high-speed response of the electrostrictive effect element of the conventional example and the example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laminated body 2a, 2b Lead wire 3a, 3b Cylindrical case 4, 4a, 4b Magnet 5a, 5b Lead terminal 6 High permeability material 7a, 7b Adhesive material 8 Magnetic fluid 9 Metal bellows 10 Electrostrictive ceramic member 11a Internal electrode conductor 11b External electrode conductor

Claims (1)

(57) [Claims] 1. A first cylinder fixed to a first end face of a laminated body in an electrostrictive effect element in which a laminated body in which plate-shaped electrostrictive ceramic members and internal electrode conductors are alternately laminated is packaged in a case. A first cylindrical case, a magnet, and a second cylindrical case fixed to the second end surface at a portion where the first cylindrical case and the second cylindrical case face each other. Are fixed, and the second cylindrical case and the magnet or the member made of the high magnetic permeability material are fixed, and the magnet fixed to the first cylindrical case and the magnet fixed to the second cylindrical case or An electrostrictive element comprising a magnetic fluid in a gap between a member made of a high magnetic permeability material.