JPH0979858A - Protection construction of vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize the whole while maintaining protection function of a vibrator by forming the inside face of a case surrounding the circumference of the vibrator into a projecting shape in the vibrating direction facing to the vibrator. SOLUTION: In this vibrator 1, a square pole-like vibrator 3 is weld joined with two thin supporting wires 4 connected to base plates 5a, 5b, and supported capably of vibrating in y-direction. For preventing deformation due to the external force of the supporting wires, magnetization or humidification of the vibrator 3, or the like, a case 2 of rectangular parallelepiped including a pedestal 6 is arranged so as to surround the circumference of the vibrator 1, and hence the vibrator 1 is protected. In this case, the top board 2a of the case 2 opposite to the vibrating direction (y) of the vibrator 1 is formed into a projecting shape rounded facing to the vibrator 1. Hereby, the reflected wave of an acoustic sound at the inside face of the case 2 is effectively diffused, and the influence of the reflected wave on the vibration attitude of the vibrator 1 can be effectively reduced. Consequently, the case 2 can be arranged close to the vibrator 1, and the whole can be miniaturized while maintaining the protection function of the vibrator 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective structure for a vibrator used in a vibration gyro or the like, and more particularly to a protective structure for a vibrator capable of sufficiently stabilizing the flexural vibration posture of the vibrator. .

[0002]

2. Description of the Related Art Conventionally, in a vibrator used in a vibration gyro or the like, a rectangular parallelepiped case 2 including a pedestal 6 is arranged so as to surround the circumference of the vibrator 1 as shown in FIG. Thus, for example, during handling, it is possible to prevent the vibrator 1 from being deformed due to an external force or the like being directly applied to the vibrator 1, or to block the vibrator 1 from the outside air to improve the moisture resistance, or the case 2 The material of (1) is made conductive or ferromagnetic so that the vibrator 1 is protected by providing an electromagnetic shield.

That is, the vibrator 1 has, for example, a vibrating body 3 made of, for example, a constant elastic alloy or the like and in the shape of a quadrangular prism, and a position corresponding to a node on a ridge line facing each other,
Alternatively, at a position in the vicinity thereof, the vibrating body 3 is joined to the two gate-shaped thin supporting wires 4 connected to the substrates 5a and 5b, respectively, by welding or the like so that the vibrating body 3 can be vibrated in the y direction. ing.

In the vibrator 1 having such a structure, the support wire 4 is deformed by an external force exceeding the support strength determined in relation to the diameter and material of the support wire 4, or the characteristics of the vibrating body 3 are concerned. Problems such as magnetization when the vibrating body 3 is made of a constant elastic alloy or the like, moisture absorption problems when the vibrating body 3 is made of ceramic or the like, or problems caused by exposure to a bad environment such as electric noise or dew condensation. is there. For this reason,
As described above, by protecting the vibrator 1 with the case 2, the occurrence of such a problem is prevented.

[0005]

By the way, recently, for example, in a vibration gyro, downsizing has been demanded, and accordingly, the vibrator 1 is also downsized. In this case, in particular, if the dimension of the vibrating body 3 in the longitudinal direction (z direction) is shortened, the vibrator 1 can be effectively downsized.

However, when the longitudinal dimension of the vibrating body 3 is shortened, the frequency of the vibrator 1 increases in inverse proportion to the square of the length, and the directivity of the acoustic wave emitted from the vibrator 1 accordingly. It becomes sharp and easy to concentrate in one direction.

For example, as shown in FIG. 8, when a vibrating body 3 having a quadrangular cross section vibrates in the y direction, which is one of the diagonal directions of the cross section, the side faces 3a, 3b, 3 respectively.
Acoustic waves 8 are radiated from c and 3d in a direction orthogonal to each side surface. Here, when the acoustic wave 8 on each side surface is decomposed into a y-direction component that is a vibration direction and an x-direction component that is orthogonal thereto, the acoustic waves 8 radiated from the side surfaces 3a and 3d have opposite x-direction components. It becomes a phase and is offset,
The y-direction component has the same phase and is emphasized. Similarly, the acoustic wave 8 radiated from each of the side surfaces 3b and 3c is also x
The directional components have opposite phases and are offset, and the y-direction components have the same phase and are emphasized.

As described above, when the vibrator 1 vibrates, an acoustic wave is generated with directivity in the vibration direction, and the directivity becomes sharper as the frequency of the vibrator 1 increases and the number of vibrations increases. Therefore, when the case 2 is arranged near the vibrator 1, the acoustic waves 8 are particularly concentrated and projected on the top plate 2a of the case 2 orthogonal to the vibration direction of the vibrator 1. Therefore, as shown in FIG. 9, the reflected wave 9 of the acoustic wave 8 reflected by the top plate 2a is not weakened and is again transmitted to the vibrator 1.
Will return to.

As shown in FIG. 7, when the vibration direction of the vibrator 1 and the top plate 2a of the case 2 are ideally and exactly orthogonal to each other, the reflected wave 9 on the top plate 2a is Since it acts evenly on the vibrator 1, it does not affect the vibration posture of the vibrator 1, but in the actual assembly, the vibrator 1
Since there are variations in the relative mounting positions and angles of the case 2 and the case 2, the reflected wave 9 acts non-uniformly on the vibrator 1.

As described above, in the conventional vibrator protection structure, the vibration posture of the vibrator 1 changes and becomes unstable due to the mounting of the case 2, so that even if the vibrator 1 is downsized, There is a problem in that the case 2 cannot be brought close to it, which makes it impossible to effectively reduce the size of the case 2 as a whole.

The object of the present invention has been made in view of the above-mentioned problems of the prior art, and is appropriately configured so as to effectively downsize the whole while sufficiently maintaining the above-mentioned protection function of the vibrator. It is to provide a protective structure for a vibrator.

[0012]

In order to achieve the above object, the protective structure for a vibrator according to the present invention has a case arranged so as to surround the periphery of the vibrator in order to protect the vibrator. At least a part of the inner surface of the element is formed in a convex shape toward the vibrator in the vibration direction.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the convex portion formed on the case acts to diverge the acoustic wave from the vibrator reflected by this portion and reduce the directivity of the reflected wave. . That is, for example, as schematically shown in FIG. 1, when the plate 11 having a convex shape is opposed to the traveling direction of the acoustic wave 8, the acoustic wave 8 is incident on the plate 11 at a certain incident angle. Therefore, the reflected wave 9 advances so as to spread to the outside.

Therefore, the density of the reflected wave 9 decreases,
Since the sound pressure of the reflected wave that directly acts on the vibrator is reduced, it is possible to reduce the change in the vibration posture of the vibrator due to the sound pressure of the reflected wave 9.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a first embodiment of the present invention. In this embodiment, in the configuration shown in FIG. 7, the top plate 2a of the case 2 for protecting the vibrator 1 facing the vibration direction (y direction) of the vibrator 1 is rounded toward the vibrator 1. It has a convex shape, for example, a shape forming a part of a cylinder extending in the z direction or a shape forming a part of a spherical shell, and the other configurations are the same as those in FIG. 7. Therefore, a member having the same function as the member shown in FIG.
The same reference numerals are given and the description thereof is omitted.

In this way, if the top plate 2a of the case 2 facing the vibration direction (y direction) of the vibrator 1 is formed in a rounded convex shape toward the vibrator 1, the vibrator 1 radiates. The reflected wave of the acoustic wave reflected by the top plate 2a is generated by the vibrator 1
Since it propagates so as to spread in the width direction of x, that is, the x direction,
The density of the reflected wave is reduced. Therefore, it is possible to effectively suppress the change in the vibration posture of the vibrator 1 due to the sound pressure of the reflected wave.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, in the configuration shown in FIG. 2, the top plate 2a of the case 2 has a V-shaped convex shape toward the vibrator 1. The V-shaped top plate 2a is
The vibrator 1 is formed uniformly in the longitudinal direction (z direction) of the axis of the vibrator 1, or is not formed uniformly, for example, is formed in an inverted pyramid shape.

If the top plate 2a is formed in a V shape toward the vibrator 1 as described above, the incident angle of the acoustic wave to the top plate 2a is increased even in the portion near the center of the axis of the vibrator 1. can do. Therefore, since the reflected wave of the acoustic wave on the top plate 2a can be diffused more widely in the x direction than in the first embodiment, it is possible to more effectively suppress the change in the vibration posture of the vibrator 1 due to the sound pressure of the reflected wave. can do.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, the shape of the top plate 2a of the case 2 is a cylindrical shape that is located on both sides of the vibrator 1 in the width direction, that is, in the x direction with the vicinity of the center of the vibrator 1 as a boundary, and extends in the axial direction. Each of them is bulged toward the outside of the case 2 so as to form a part or a part of a spherical shell shape, and has a convex shape toward the vibrator 1 near the center of the axis of the vibrator 1.

According to this structure, since the incident angle of the acoustic wave on the top plate 2a can be made larger in the portion near the center of the axis of the vibrator 1, the reflected wave of the acoustic wave on the top plate 2a can be reduced. , Can be diffused more widely in the x direction than in the second embodiment. Therefore, the change in the vibration posture of the vibrator 1 due to the sound pressure of the reflected wave can be suppressed more effectively.

FIG. 5 shows a fourth embodiment of the present invention. This embodiment is similar to the first embodiment except that the top plate 2a is
Is formed in a rounded convex shape toward the vibrator 1 so as to form a part of a cylinder extending in the width direction (x direction) of the vibrator 1.

According to this structure, the reflected wave of the acoustic wave on the top plate 2a can be widely diffused in the z direction. Therefore, as in the case of the first embodiment, the vibration of the vibrator 1 due to the sound pressure of the reflected wave. It is possible to effectively suppress changes in posture.

FIG. 6 shows a fifth embodiment of the present invention. This embodiment is applied when the vibrator 1 vibrates in the x direction. Therefore, in this embodiment,
Both side plates 2b of the case 2 facing the vibration direction are formed in a rounded convex shape toward the vibrator 1 so as to form a part of a cylinder extending in the y direction.

As described above, if the side plates 2b of the case 2 facing the vibration direction (x direction) of the vibrator 1 are formed in a convex shape toward the vibrator 1, reflection of acoustic waves on the side plates 2b is achieved. Since the wave can be widely diffused in the z direction, it is possible to effectively suppress the change in the vibration posture of the vibrator 1 due to the sound pressure of the reflected wave, as in the above-described embodiment. In addition, the shape of the both side plates 2b in this case is not limited to the shape shown in FIGS.
It can also be formed in a shape similar to the shape of the top plate 2a shown in FIG.

It should be noted that the present invention is not limited to the above-described embodiments, but many variations and modifications are possible. For example, the vibrating body 3 that constitutes the vibrator 1 may be formed of a material such as a constant elastic alloy, ceramic, glass, or the like, and the shape thereof may be a polygonal column or a column other than the square column. Also, the case 2 including the pedestal 6
Can be formed so as to completely seal the oscillator 1 or partially cover it. Further, the present invention can be effectively applied not only to the vibrator used for the vibration gyro but also to the protective structure of various vibrators.

[0026]

According to the present invention, since at least a part of the inner side surface of the case for protecting the vibrator is formed in a convex shape toward the vibrator in the vibration direction, the case emitted from the vibrator The reflected wave of the acoustic wave reflected on the inner surface can be effectively diffused. Therefore, it is possible to effectively reduce the influence of the reflected wave on the vibration posture of the vibrator, and thus it is possible to dispose the case close to the vibrator, thereby sufficiently maintaining the protection function of the vibrator. , The whole can be effectively miniaturized.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the operation of the present invention.

FIG. 2 is a diagram showing a first embodiment of the present invention.

FIG. 3 is also a diagram showing a second embodiment.

FIG. 4 is likewise a diagram showing a third embodiment.

FIG. 5 is likewise a diagram showing a fourth embodiment.

FIG. 6 is likewise a diagram showing a fifth embodiment.

FIG. 7 is a diagram showing a conventional example.

FIG. 8 is a diagram for explaining generation of acoustic waves.

FIG. 9 is a diagram for explaining a conventional problem.

[Explanation of symbols]

 1 vibrator 2 case 2a top plate 2b side plate 3 vibrating body 4 support wires 5a, 5b substrate 6 pedestal

Claims (1)

[Claims] 1. A vibrating body is provided with a case arranged so as to surround the vibrating body in order to protect the vibrating body, and at least a part of an inner side surface of the case is convex toward the vibrating direction in the vibrating direction. A protective structure for a vibrator, which is formed in a shape.