JPH06253392A - Piezoelectric vibration device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to realize a holding structure for a piezoelectric vibrator that is stable and has very little deterioration in characteristics. [Structure] 1 is a rectangular plate-shaped piezoelectric vibrator having electrodes 2 attached to opposite surfaces, and by applying an AC electric field to the electrodes 2, a length vibration having a main displacement in the length direction of the vibrator 1 The mode is excited. The node of this length vibration is linear in the central portion of the rectangular plate, and metal such as nickel, chromium, and aluminum having fine irregularities near the node line is linearly sprayed, and the sprayed film 3 is attached. It is held through this sprayed film 3. [Effect] By holding the piezoelectric vibrator via the sprayed film having a rough surface, the piezoelectric vibrator can be held in a state where the holding range is wide but the actual contact area is small.
As a result, the stability and reliability of the piezoelectric vibrator are improved, and it is possible to realize a device with less deterioration in characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator holding structure using a piezoelectric material such as piezoelectric ceramic, crystal, niobium lithium oxide or the like.

[0002]

2. Description of the Related Art A conventional structure of a piezoelectric vibrator holding structure using a piezoelectric material such as piezoelectric ceramics, crystal, niobium lithium oxide or the like will be described below.

Piezoelectric vibrators used for mechanical filters, oscillators, etc. are made of materials such as piezoelectric ceramics, crystal, niobium lithium oxide, etc., and an appropriate vibration mode is excited by the piezoelectric effect according to the frequency range to be used. . And
These piezoelectric vibrators are configured as a filter or an oscillator by holding them near a node where the vibration amplitude is 0 so as not to suppress vibration. Since the node at which the vibration amplitude is 0 is a point or line having no area, ideally it is desirable to hold the piezoelectric vibrator at a point or line with an area of 0. In order to realize the retention, it has a certain finite area and is retained in a dot shape or a linear shape.

FIG. 6 is a perspective view of a conventional rectangular plate type piezoelectric vibrator 11 made of a piezoelectric material such as a piezoelectric ceramic. Electrodes 12 are formed on opposing main surfaces and an electric field is applied between the electrodes. Then, the spreading vibration of the square plate is excited. The node of this vibration mode is a point at the center of the square plate, and as shown in the figure, the piezoelectric vibrator is held near the center of the piezoelectric vibrator by a holder 13 having a spring-like property having a circular flat end. Holding from both sides.

FIG. 7 is a perspective view of another conventional rectangular plate type piezoelectric vibrator 14 made of a piezoelectric material, in which the length vibration of the rectangular plate is excited. In the length vibration, the vibration node is linear in the center of the rectangle, and in the same figure, the vicinity of the node of the piezoelectric vibrator is linearly held by a holding tool 15 having a certain width.

In these conventional holding structures, when the holding area is small, the holding becomes unstable, and when the holding area is large, the vibrating portion is held down, so that the vibration is suppressed and the vibration is suppressed. The characteristics of the child deteriorate.

[0007]

The conventional piezoelectric vibrator holding structure does not deteriorate the characteristics because the piezoelectric vibrator has a certain area and is directly held by a holding tool in a dot shape or a linear shape. When the holding area is reduced as described above, the holding becomes unstable, and when a shock such as a drop is applied, the posture of the vibrator changes, and the characteristics also change. And
If the holding area is increased in order to stabilize the holding, the vibrating part will be pressed down, and the vibration of the vibrator will be suppressed, so the characteristics will deteriorate and the effect on the vibrator characteristics will be small. There is a problem that it is difficult to realize reliable and stable holding.

[0008]

A metal or ceramic sprayed film is formed on at least one of a vibration node of a piezoelectric vibrator and a part of a holder for holding the piezoelectric vibrator. Holds the piezoelectric vibrator.

[0009]

[Function] A metal or ceramic sprayed film having fine irregularities on the surface is formed on at least one of the vibrating nodes of the piezoelectric vibrator, or at least one of the holders for holding the piezoelectric vibrator. By holding the piezoelectric vibrator through the film, even if the contact area between the piezoelectric vibrator and the holder is increased, the effective contact area can be reduced due to the fine irregularities on the surface of the sprayed film. Therefore, by increasing the area for holding, the stability and reliability are improved, and by reducing the effective contact area, it is possible to realize the holding of the piezoelectric vibrator with less deterioration of the characteristics.

[0010]

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

FIG. 1 is a perspective view of a piezoelectric vibrator used in a holding structure according to an embodiment of the present invention. In the figure, reference numeral 1 is a rectangular plate-shaped piezoelectric vibrator made of a piezoelectric material such as piezoelectric ceramic, crystal, niobium lithium oxide, etc., and an electrode 2 is attached to the opposite surface, and an alternating electric field is applied to the electrode 2. Due to
A length vibration mode having a main displacement in the length direction of the vibrator 1 is excited.

The node of this length vibration is linear in the central portion of the rectangular plate, and there is fine unevenness in the vicinity of this node line.
A metal such as chrome or aluminum is linearly sprayed to apply the sprayed film 3. FIG. 2 shows a holding structure of the piezoelectric vibrator 1 of FIG. 1, in which the piezoelectric vibrator 1 is held so as to be sandwiched by a holder 4 having a spring property via a sprayed film 3.

FIG. 3 is a perspective view of a piezoelectric vibrator used in a holding structure according to another embodiment of the present invention. In the figure, reference numeral 5 denotes a disk-shaped piezoelectric vibrator having electrodes 6 attached to opposite surfaces,
By applying an AC electric field to the electrode 6, it is possible to excite a radial spreading vibration mode having a main displacement in the radial direction of the vibrator 5. The node of this vibration is a point at the center of the disk, and a metal having fine irregularities is sprayed in the shape of a disk in the vicinity of this node to attach the sprayed film 7. FIG. 4 shows a holding structure of the piezoelectric vibrator 5 of FIG. 3, in which the piezoelectric vibrator 5 is held so as to be sandwiched by a holder 8 having a spring property via a sprayed film 7.

FIG. 5 is an enlarged view of the holding portion of the holding structure of the piezoelectric vibrator in each of the above-described embodiments. The surface of the sprayed film 10 formed on the piezoelectric vibrator 9 has a fine pattern peculiar to the sprayed film. Since there is such unevenness, the contact with the holder 11 becomes partial, and even if the contact portion for holding the piezoelectric vibrator 9 and the holder 11 is increased in order to stabilize the holding, an effective contact area is obtained. Can be made smaller. Therefore, the suppression of the vibration of the piezoelectric vibrator 9 can be reduced, and the vibration leaking through the holder can be reduced, so that the deterioration of the characteristics of the piezoelectric vibrator 9 due to the holding can be extremely reduced.

In the above embodiment, the piezoelectric vibrator is formed with a metal film by thermal spraying, but the same effect can be obtained by spraying ceramics or the like. Further, in the above embodiment, the sprayed film is formed on the piezoelectric vibrator, but even if the metal or ceramic is sprayed on the holder and the vibrator is held through this sprayed film, Needless to say, the same effect can be obtained by spraying metal or ceramic on both the piezoelectric vibrator and the holder and holding the vibrator through the sprayed film.

[0016]

EFFECTS OF THE INVENTION A metal or ceramic is sprayed on at least one of a vibration node of a piezoelectric vibrator or a part of a holder for holding the piezoelectric vibrator to form a sprayed film having fine irregularities on the surface. By holding the piezoelectric vibrator through this sprayed film, even if the area of the holding part is increased, the effective contact area can be reduced because the surface has fine irregularities. It is possible to simultaneously realize both stable holding by increasing the value and holding with less deterioration of the characteristics by decreasing the effective contact area.

Further, by holding the piezoelectric vibrator through the sprayed film of an elastically stable inorganic material such as metal or ceramic, the sprayed film is not plastically deformed by the holder, so that the film thickness is reduced. Therefore, the influence of the sprayed film on the piezoelectric vibrator can be minimized, and stable holding with little change over time can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a piezoelectric vibrator in an embodiment of a piezoelectric vibration device of the present invention.

FIG. 2 is a cross-sectional view showing the configuration of the apparatus of the embodiment.

FIG. 3 is a perspective view of a piezoelectric vibrator according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing the configuration of the apparatus of the embodiment.

FIG. 5 is an enlarged view of a holding portion of the piezoelectric vibrator in the device of the embodiment.

FIG. 6 is a perspective view showing the configuration of a conventional piezoelectric vibration device.

FIG. 7 is a perspective view showing the configuration of another conventional piezoelectric vibration device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrator 2 Electrode 3 Thermal spray film 4 Holder 5 Piezoelectric vibrator 6 Electrode 7 Thermal spray film 8 Holder 9 Piezoelectric vibrator 10 Thermal spray film 11 Holder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taketoshi Yonezawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A piezoelectric vibrating device having a piezoelectric element using a piezoelectric material and a holder for holding the piezoelectric element, wherein the piezoelectric vibrating device is provided near a vibration node of the piezoelectric vibrator or holding the piezoelectric vibrator. A piezoelectric vibrating device, wherein a film having a rough surface is formed on at least one of the parts of the tool, and the piezoelectric vibrator is held via the film. 2. The piezoelectric vibrating device according to claim 1, wherein the film is a sprayed film formed by spraying a metal or a ceramic.