JPS61276278A - Laminated type piezoelectric body - Google Patents

Abstract

PURPOSE:To prevent the generation of relative positional movement to vibrations, etc. and even during driving of several piezoelectric plate, and to maintain the stable state of laminating by bending a metallic plate toward the side surfaces of the piezoelectric plates in the bent section of the metallic plate. CONSTITUTION:A laminated type piezoelectric body A is further bent so that both side end sections of the bent sections 11a, 11b of each ribbon-shaped metallic plate 11, 12 are brought into contact with piezoelectric plates 10, thus laminating the piezoelectric plates 10 at stable positions, then resulting in no mutual relative positional movement of the piezoelectric plates 10 even when high-frequency voltage is applied to the laminated type piezoelectric body and the piezoelectric body is driven. Accordingly, trouble such as short circuit among the metallic plates during driving or cracking due to collisions with a casing, etc. of the piezoelectric plates 10 is also eliminated.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a laminated piezoelectric device that is formed by laminating a large number of plate-like members made of piezoelectric elements, expands and contracts in response to applied voltage, and acts as an actuator. Regarding the body.

(Prior Art) A conventional laminated piezoelectric body includes, for example, a piezoelectric plate having a circular shape and electrodes formed on both sides, and a metal plate having approximately the same shape as the piezoelectric plate and having one protrusion on the periphery. and,
These piezoelectric plates and metal plates are stacked alternately, and the protrusions of each metal plate face in the opposite direction to the adjacent ones and are electrically connected to the protrusions of the adjacent metal plate. A positive terminal and a negative terminal are formed. However, in such a laminated piezoelectric body, the protrusions are usually connected by spot welding or the like, but there is a problem in that the welded portions peel off when the laminated piezoelectric body is operated at a high frequency. Furthermore, if the metal plate has cracks or the like, the piezoelectric plate will crack or the amount of displacement will decrease under high loads, so it is usually difficult to press-form metal plates, and electric discharge machining or the like must be used. Therefore, there was also a problem that the cost of the metal plate was extremely high.

(Problems to be Solved by the Invention) The present invention has been made in view of the above points, and its main purpose is to provide a laminated piezoelectric material in which the metal plate for voltage application has a simple ribbon shape. The object of the present invention is to make it possible to use a simple cutting process that is easy to process, and to reduce the possibility that the laminate will be damaged or the amount of displacement will decrease.

- There is a prior art (Japanese Patent Application No. 58-210707) by the applicant of the old patent application in order to achieve the same object as above, and a basic embodiment thereof is disclosed. The present invention is based on the prior art described above, and provides a layered piezoelectric material with further technical improvements.

Another object of the present invention is to maintain a stable laminated structure without shifting the relative positions of the metal plate and the piezoelectric plate even when the laminated piezoelectric body is driven under any conditions where external vibrations or the like act. The object of the present invention is to provide a laminated piezoelectric material that has the following properties.

(Means for solving the problem) The present invention includes a plurality of piezoelectric plates formed from piezoelectric elements, a first ribbon-shaped metal, and a second ribbon-shaped metal, and the first and second ribbon-shaped metal plates are provided. Two ribbon-shaped metal plates are bent at the bending portion and inserted between the predetermined piezoelectric plates, and the plurality of piezoelectric plates and the first and second ribbon-shaped metal plates are alternately superimposed and laminated. At the same time, the first
and a second ribbon-shaped metal plate is bent toward the side surface of the piezoelectric plate, and a terminal of one polarity is connected to the first ribbon-shaped metal plate via a lead wire, and a second ribbon-shaped metal plate is connected to the first ribbon-shaped metal plate through a lead wire. Terminals of the other polarity are connected to each other via lead wires.

(Example) Next, an example of the present invention will be described based on the drawings. 1st
4 to 4 show a first embodiment of the present invention,
FIG. 1 is a partial side view of a laminated piezoelectric body, FIG. 2 is a plan view of a ribbon-shaped metal plate, and FIGS. 3 and 4 are diagrams for explaining the lamination process.

Silver electrodes (not shown) are concentrically formed on both sides of a plurality of piezoelectric plates 10 each having a piezoelectric element formed into a disk shape with a diameter of 15 fl and a thickness of 0.5 van.

1 for voltage application shown in FIG. Second metal plate 11
．． 12 has a ribbon shape in which the bent portions 11a and 12a are periodically formed by notching, and is made of, for example, a stainless steel plate with a thickness of about 20 μm.

These plurality of piezoelectric plates 10 and the first . Second metal plate 11
．． 12 are alternately polymerized and laminated to form the laminate A shown in FIG. Second metal plate 11.12
Both sides 11b and 12b of the bent portions 11a and 12a are further bent toward the side surface of the piezoelectric plate 10. Further, the first and second metal plates 11 and 12 each have a lead wire 1.
3.14 is connected.

Next, FIG. 3 shows the laminated state of this laminate A.

To explain in detail based on FIG. 4, first, the piezoelectric plate 10 is set on the first metal plate 11, and then the piezoelectric plate 1
After setting the second metal plate 12 on the top surface of 0, then setting another piezoelectric plate 12 on top of the second metal plate 12, bend the first metal plate 1 at the bending part 11a. It's layered.

If this is shown in the state in the middle of lamination in Fig. 3, after placing the piezoelectric plate 1o, bend the metal plate 12 backward in the figure from the bending part 12a (the state shown in Fig. 3), and then place another layer on top of it. Piezoelectric plate 1
After setting 0, the metal plate 11 is bent to the right from the bending portion 11a. After inserting another piezoelectric plate 1o, the metal plates 12 are bent toward the front and stacked alternately.

After that, each bent portion 11a, 12 of each metal plate 11.12
As shown in FIG. 4, both sides 11b and 12b of
The piezoelectric plate 10 is bent toward the side surface of the piezoelectric plate 10 so that the ends of both sides 11b and 12b thereof are in contact with the side surface of the piezoelectric plate 10. This laminated piezoelectric body A is inserted into an insulating case made of resin or the like. Alternatively, the bent portions 11a of the metal plates 11 and 12 are brought into contact with another metal plate on the side surface parallel to the laminated axis of the laminated piezoelectric body A.

The laminated state is maintained by spot welding with 12a. The length of the laminated piezoelectric body is about 40 m, and it has a structure in which about 75 piezoelectric plates 10 are laminated.

Both lead wires 13.1 of the laminated piezoelectric body A having such a configuration
When a voltage of 500 to 700 V is applied to the piezoelectric plate 4 in the polarization direction, the piezoelectric plate expands and contracts by 50 to 70 microns in the axial direction, thereby acting as an actuator.

The laminated piezoelectric body A shown in FIG.
Since both ends of b are further bent so as to contact the piezoelectric plate 0, the piezoelectric plates 10 are stacked in a stable position, and when a high frequency voltage is applied to the laminated piezoelectric material to drive it. However, the piezoelectric plates 10 do not move relative to each other. Therefore, problems such as short circuits between the metal plates during driving, or the piezoelectric plates 10 colliding with the casing (not shown) or the like and breaking are also solved. In addition, metal plate 11.12
In order to further bend both sides of the bent portions 11a and 12a, for example, the portions 11b and 12b to be bent can be easily bent by pushing them toward the sides of the piezoelectric element.

Furthermore, instead of bending, the piezoelectric plate 10 can be fixed together by tightening the bent portions 11a and 12a from the sides of the laminated piezoelectric body A toward the center. Furthermore, although the piezoelectric plate 10 used in the above-mentioned embodiments is disk-shaped, a piezoelectric body 15 with a part of the four corners of a rectangle cut out as shown in FIG. 6 is used as shown in FIG. Ribbon-shaped metal plate 1
The same effect as in the above-mentioned embodiment can be obtained by bending both sides 16b of each bent portion 16a toward the side surface of the piezoelectric plate 15 with respect to the laminated piezoelectric body alternately laminated by the piezoelectric body 6.

Next, another example of the ribbon-shaped metal plate will be described.

The metal plates 11' and 12' shown in FIG. 7 are cut in four places from both sides along the lines bent at the narrowest bends 11a and 12a of the metal plates 11 and 12 shown in FIG. It contains llc and 12c. This metal plate 11
After stacking the piezoelectric plates 10 alternately in the same manner as in the above-mentioned embodiment using The piezoelectric plate 10 is folded toward the side and is stacked and fixed in contact with the side surface of the piezoelectric plate 10. The outer shape of the laminated piezoelectric body at this time is almost the same as that of the above embodiment, but the metal plates 11', 12
' is the piezoelectric plate 1 compared to the metal plates 11 and 12 of the above embodiment.
Since each piezoelectric plate 10 is sufficiently contacted with the side surface of 0, each piezoelectric plate 10 is firmly fixed, and relative positional movement becomes even more difficult to occur.

Incidentally, the notches should be made in the metal plates not only in the ribbon-shaped metal plates 11 and 12 of the disk-shaped piezoelectric plate 10 shown in FIG. 2, but also in the ribbon-shaped metal plates 16 for the square piezoelectric plate 15. I can do it. Furthermore, a piezoelectric plate 10.15 and a metal plate 1
1.12. ll'.

In order to reduce the relative movement between the piezoelectric plates 12' and 16, grooves or the like are formed along both sides of the bent portion of the metal plate, that is, along the axial direction of the piezoelectric plate on the side surfaces of the piezoelectric plates 10 and 15. It goes without saying that both sides of the bent portion of the metal plate may be bent so as to contact or engage with this cut groove.

(Effects of the Invention) As described above, since the metal plate is bent toward the side surface of the piezoelectric plate at the bent portion of the metal plate, each piezoelectric plate is resistant to vibrations, etc., and even during driving. Relative positional movement is less likely to occur, and a stable stacked state can be maintained. Therefore, the possibility of problems such as short circuits between metal plates is greatly reduced, improving the durability and reliability of the laminated piezoelectric material, and since the metal plates have a ribbon shape, lamination assembly is easy. It can be produced in large quantities and has excellent productivity.

[Brief explanation of drawings]

FIG. 1 is a partial side view of a laminated piezoelectric body showing an embodiment of the present invention, FIG. 2 is a plan view of a ribbon-shaped metal plate, FIGS.
The figures are for explaining the lamination of laminated piezoelectric bodies.
6 are diagrams showing a ribbon-shaped metal plate and a piezoelectric plate when piezoelectric plates of different shapes are laminated, respectively, and FIG. 7 is a plan view showing another ribbon-shaped metal plate. 10... Disk-shaped piezoelectric plate, 11.12... Ribbon-shaped metal plate, lla, 12a... Bent part, llb, 12b.
...Both sides of the bent part, IIC, 12c...notch, 1
3.14... Lead wire, 15... Square piezoelectric plate, 1
6... Ribbon-shaped metal plate, 16a... Bent portion.

Claims (2)

[Claims] (1) A plurality of piezoelectric plates formed from piezoelectric elements, and a first
and a second ribbon-shaped metal plate, the first and second ribbon-shaped metal plates are bent at a bending part and inserted between predetermined piezoelectric plates, and the plurality of piezoelectric plates The plate and the first and second ribbon-shaped metal plates are alternately stacked and stacked, and the first and second ribbon-shaped metal plates are folded toward the side surface of the piezoelectric plate at the bending portion. A terminal of one polarity is connected to the first ribbon-shaped metal plate via a lead wire, and a terminal of the other polarity is connected to the second ribbon-shaped metal plate via a lead wire. A laminated piezoelectric body characterized by: (2) The laminated piezoelectric material according to claim 1, wherein the bent portion of the metal plate is provided with a cut along a bending line formed during lamination.