JPH058691Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrostrictive element, and particularly to a casing structure of an electrostrictive element.

[Conventional technology]

Conventionally, a laminated type electrostrictive element has a structure as shown in Fig. 2a and b, where 1 is a ceramic electrostrictive material layer made of lead zirconate titanate having a composite perovskite structure, and 2 is an electrostrictive material layer made of ceramic lead zirconate titanate having a composite perovskite structure. This is an internal electrode layer using a silver-palladium alloy disposed to sandwich the material layer 1. 3 is an insulating material coated to insulate every other end face of the internal electrode layer 2, and 4 is an external electrode coated with a conductive paste to electrically connect every other internal electrode layer 2. It is a layer. 5 is made of the same material as the external electrode layer 4;
This is an end face electrode layer electrically connected to. 6 is a protective layer coated with resin to electrically insulate the entire side surface.

[Problems to be solved by the invention] In the above-mentioned conventional electrostrictive effect element, (a) cracks and chips occur in the portions of the protective layer not covered with the resin during handling.

(b) A separate mechanism is required to apply compressive force in the vertical direction.

There is a drawback.

[Means for solving problems]

The object of the present invention is to provide an electrostrictive effect element that eliminates such conventional drawbacks.

According to the present invention, a columnar electrostrictive element with end electrodes led out on the upper and lower surfaces is housed in a conductive cylindrical exterior case, and a T-shaped cross-section is placed on the upper surface of the electrostrictive element. An electrostrictive effect element characterized in that an electrical insulating material is interposed between the electrode plate and the edge of the outer case is caulked is obtained.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1a is a plan view of an electrostrictive effect element according to an embodiment of the present invention, and FIG. 1b is a sectional view thereof. 1 in the diagram
2 is a ceramic electrostrictive material layer made of lead zirconate titanate having a composite perovskite structure.
is an internal electrode layer using a silver-palladium alloy disposed so as to sandwich the electrostrictive material layer 1 therebetween. 3 is an insulating material such as glass deposited to insulate every other end face of the internal electrode layer 2, and 4 is an external electrode layer coated with a conductive paste to connect every other internal electrode layer 2. be. Reference numeral 5 denotes end electrode layers which are disposed on the upper and lower surfaces of the electrostrictive material layer 1 and are made of the same material as the external electrode layer 1 and connected to the external electrode layer 1. Reference numeral 7 denotes an upper electrode plate having a T-shaped cross section, and 8 an upper surface of an electrical insulating material 9 having a substantially U-shaped cross section, which is inserted between the outer case 8 and the upper electrode plate 7 by bending the edge 8a inward. It is a hardened exterior case.

Next, a method for manufacturing the electrostrictive element of the present invention will be explained. That is, a ceramic calcined powder made of lead titanate or the like is prepared and dispersed in an organic solvent such as ethyl cellosolve together with a small amount of an organic binder such as polybutyral resin and a plasticizer such as dioctyl phthalate to form a slurry. This slurry is fluidly applied onto a polyester film having a thickness of 100 μm by a slip casting method using a doctor blade, and a green sheet serving as the electrostrictive material layer 1 having a thickness of 70 μm is adhered thereon. Next, after forming the internal electrode layer 2 in a predetermined shape by screen printing a conductive paste such as silver-palladium paste on the green sheet, the green sheet in the area where the internal electrode layer 2 was printed is cut into a predetermined size. Peel off from polyester film. A desired number of green sheets are stacked and pressed from above and below using a hot press to form a laminate in which electrostrictive material layers 1 and internal electrode layers 2 are alternately arranged.

Next, the organic binder contained in this laminate is decomposed at high temperature to evaporate and removed, and then the temperature is raised to 1120°C at a rising speed of 5°C/min.
Sintering is carried out by holding the temperature at 1120°C for 2 hours. Next, the sintered laminate is cut into a grid pattern to expose the end faces of the internal electrode layers 2. On one side, an insulating material 3 such as glass is deposited every other layer on the end surface of the internal electrode layer 2 by electrophoresis, and on the other side, an internal electrode layer is coated with no insulating material 3. An insulating material 3 is coated on the end face opposite to 2. In order to electrically connect the upper surface of each insulating material 3 to the internal electrode layer 2 which is not coated with an insulating material, a conductive paste such as silver paste is printed by screen printing to form an external electrode layer 4. Form. Next, a conductive paste such as silver paste is printed on the upper and lower surfaces of the laminate by screen printing to form an external electrode layer 4.
The end face electrode layer 5 is formed by printing so as to be electrically connected to the end face electrode layer 5. Next, the top and bottom surfaces of the laminate cut by means such as ultrasonic processing are brought into contact with the upper electrode plate 7 and the outer case 8 made of metal, respectively, and pressure is applied from the top and bottom of the laminate using a press or the like. While maintaining this state, the edge 8a of the outer case 8 is passed through the electrical insulating material 9, which is passed through the protrusion 7a of the upper electrode plate 7.
Fold it inward and caulk it to seal.

[Effect of idea]

As explained above, the present invention has the following effects.

(a) Since the electrostrictive material layer is not exposed, no cracking or chipping occurs during handling.

(b) Compressive force is applied in the vertical direction of the electrostrictive element by caulking the edge of the metal case, so there is no need to apply compressive force.

Although the electrostrictive effect element of this embodiment has a circular cross section, it may have a rectangular or polygonal cross section.

[Brief explanation of drawings]

1A and 1B are a plan view of an electrostrictive effect element of the present invention, and FIGS. 2A and 2B are a plan view and a sectional view of a conventional electrostrictive effect element. DESCRIPTION OF SYMBOLS 1... Electrostrictive material layer, 2... Internal electrode layer, 3... Insulating material, 4... External electrode layer, 5... Edge electrode layer, 6... Insulating protective layer, 7... Upper electrode plate, 8...
Exterior case, 9...Electrical insulating material.

Claims (1)

[Scope of utility model registration request] A columnar electrostrictive element having end electrodes on the upper and lower surfaces is housed in a conductive cylindrical outer case, and the outer case and the end electrode on the lower surface are electrically connected, and the electrostrictive element is An electrostrictive effect element characterized in that an electrical insulating material is interposed between an upper electrode plate having a T-shaped cross section placed on an end electrode on the upper surface of the effect element, and the end of the outer case is caulked.