JP3352856B2 - Transducer protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection device for protecting a vibrator for use in a vibration type gyroscope used in a navigation system or a camera shake preventing mechanism, and particularly has excellent shock resistance against dropping and the like. The present invention also relates to a vibrator protection device having excellent shield characteristics.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view showing a vibration type gyroscope using a tripod tuning fork type vibrator. In the vibratory gyroscope shown in FIG. 7 , reference numeral 2 denotes a vibrator, and reference numeral 3 denotes a support. The vibrator 2 has a cantilever structure in which a base 2 d is rigidly supported by a support 3. Vibrating pieces 2a, 2b, and 2c are formed in a branch at the tip of the vibrator 2. The vibrator 2 is formed by laminating a piezoelectric material on both front and back surfaces of a constant elastic metal plate such as an elinvar, or is formed entirely of a piezoelectric material. Each vibrating bar 2
Each of a, 2b, and 2c is provided with a drive electrode for vibrating in the X direction and a detection electrode for detecting a vibration component in the Y direction.

An AC drive voltage of the same phase is applied to the driving electrodes of the vibrating bars 2b and 2c on both sides of the vibrating bars provided on the vibrator 2, and the driving electrode of the central vibrating bar 2a is vibrated. An AC drive voltage having a phase opposite to that of the pieces 2b and 2c is applied. As a result, the vibrating bars 2b and 2c on both sides and the central vibrating bar 2a are vibrated in the X direction in phases opposite to each other (a phase different by 180 degrees).

When the vibrating gyroscope in which the above-mentioned vibration occurs is placed in a rotating system around the Z-axis, the vibrating reed 2
a, 2b, and 2c, a Coriolis force in the Y direction having a magnitude proportional to the speed in the X direction acts on each of the vibrating bars 2a, 2b, and 2c.
b and 2c have a vibration component in the Y direction. Also in this vibration in the Y direction, the vibrating bars 2b and 2c on both sides
And the central vibrating reed 2a have opposite phases (180
Degrees). Vibration components in the Y direction of the respective vibrating bars 2a, 2b, and 2c are extracted from the detection electrodes, and an angular velocity ω about the Z axis is calculated from the detection output.

[0005]

Since the conventional vibratory gyroscope shown in FIG. 7 is small and the size of the vibrator 2 is small, it is very difficult to handle the vibrator 2 as a single component. is there. Also, if the vibrator 2 is accidentally applied to another component or dropped during transportation, storage of parts, or incorporation into a product, the vibrator 2 is damaged and becomes unusable.

It is also considered that the vibrator is housed in a case to be made into a chip component. However, since the vibrator must be supported so as to be able to vibrate in the case, the vibrator is housed in the case with some degree of freedom. Therefore, when a strong impact such as a drop is given to the case, the vibrator is easily damaged in the case.

Further, since the vibrator 2 vibrates at a very high frequency, high-frequency noise due to the vibration adversely affects other circuits. Therefore, it is necessary that the vibrator be incorporated into the product while being securely shielded.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a vibrator protection device capable of supporting a vibrator in a state strong against impact and having a high shielding effect.

[0009]

According to the present invention, there is provided a protection device in which a vibrator having a plurality of vibrating pieces branched at a tip is incorporated, wherein the vibrator has a base on which the vibrating piece is not formed. Is sandwiched by a support member formed of an elastic material, and is a shield body made of a single metal plate.
Wherein the base of the vibrator is supported via the support member between the open ends of the bent portion .

The shield is formed by bending a metal plate into a U-shape.
It can be formed as a slab.

Further, the support of the vibrator is provided in the shield body.
It is also possible to adopt a configuration in which the member is supported and the middle part of the vibrator is elastically supported.

Further, it is preferable that the shield body has a support structure in which a portion of the vibrator opposite to the support side is supported on a base.

Further, it is possible to adopt a structure in which the upper and lower portions of the shield are sandwiched between elastic bodies, and the shield and the elastic body are housed in a case.

In the vibrator protection device according to the present invention, the base of the vibrator is supported by the shield while at least both sides of the vibrator are covered by the shield. Therefore, the impact is not directly transmitted to the vibrator when the vibrator hits another component, and the vibrator is easily prevented from being damaged. Further, the radiation noise of the ultrasonic wave due to the vibration of the vibrator can be shielded by the shield body. In addition, since the shield body has a shape in which the shield body faces both the front and back surfaces of the vibrator, the assembly of the shield body and the vibrator can be made thin. Also, if not only the base of the vibrator is supported in the shield, but also the center of the vibrator is elastically supported, the vibrator can perform a vibration operation inside the shield, and the vibrator can be moved to the neutral position in the shield. The vibrator does not hit the inner wall surface of the shield when an external impact is applied. Furthermore, if the shield body is formed by a metal plate bent in a U-shape,
The manufacturing process of the shield body is simplified.

When the above-described assembly of the shield and the vibrator is installed on the base, it is preferable to support the shield on the base at a portion opposite to the side on which the vibrator is supported. . In this structure, when vibration or impact is applied from the outside, the shield body vibrates with the support portion to the base as a fulcrum, and further, the vibrator vibrates inside the shield body with the support portion of the base as a fulcrum. The vibration of the shield body and the vibration of the vibrator can effectively absorb external vibrations and shocks, thereby preventing the vibrator from being damaged by the vibrations and shocks.

Further, when the above-mentioned assembly of the shield and the vibrator is sandwiched between elastic bodies and housed in a case, the vibrator can be handled in the same manner as a chip component. In this assembly, since the vibrator is housed in the shield and the shield is held by the elastic body in the case, the function of protecting the vibrator when an external force acts on the case is extremely high. When the case is formed of a shielding material, the vibrator can be double shielded. Further, when the base is a printed circuit board, it is possible to connect the wiring of the electrodes of the vibrator to the base and connect the base to an external circuit.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded perspective view showing a basic structure of a vibrator protection device used as a vibrating gyroscope. Vibrator 2 illustrated in FIG. 1 is the same as the conventional example shown in FIG. The vibrator 2 has a plate shape,
A piezoelectric material is laminated on both sides of a plate made of a constant elastic material such as an elinvar or a plate made entirely of a piezoelectric material. As described in the related art, the vibrator element 2 is formed with the vibrating reeds 2a, 2b, and 2c branched at the front end thereof. The drive electrodes for driving in the X direction and the Y direction are provided on the surface of each vibrator. There is provided a detection electrode for detecting a vibration component when the vibration occurs. The vibrating bars 2b and 2c on both sides are driven by the AC drive power applied to the drive electrodes.
Vibrates at the same phase in the X direction, and the central vibrator 2a vibrates in the X direction with a phase opposite to that described above. When placed in a rotating system around the Z axis, vibrations in the Y direction are generated in the vibrating bars 2a, 2b, 2c by Coriolis force. This vibration component is detected by the detection electrode, and the angular velocity ω about the Z axis is obtained.

In this vibrator 2, the vibrating pieces 2a, 2b and 2c branched into three vibrate, but the vibrating pieces 2b and 2c on both sides and the central vibrating piece 2a are opposite in the X direction. In the vibration in the Y direction due to the Coriolis force, the phases of the vibrating bars 2b and 2c on both sides and the center vibrating bar 2a are opposite. The direction of the amplitude of the vibrating bars 2b and 2c on both sides at a certain point in time is opposite to the direction of the amplitude of the central vibrating bar 2a. Therefore, the resonator elements 2a, 2b, 2
The balance of the entire vibrator 2 when c is vibrated is good, and it is difficult for the vibrator 2 to be twisted or the like in a portion where the vibrating piece is not formed. Therefore, even if the base 2d of the vibrator 2 is held between the support members 4 and 4 and the base 2d is firmly supported, the vibrating pieces 2a, 2b and 2c do not have much influence on the vibration operation. That is, the tripod tuning fork type vibrator 2 is suitable for forming a cantilever support structure by supporting the base with a rigid body.

The shield 1 is formed by bending a metal plate such as stainless steel into a U-shape. The support member 4 is fixed between the upper and lower metal plates 1a and 1b at the open end of the shield body 1. The base 2 d of the vibrator 2 is sandwiched between the metal plates 1 a and 1 b and the support members 4 and 4 at the open end of the shield 1, and the vibrating bars 2 a, 2 b and 2 c extend toward the bent portion 1 c of the shield 1. The vibrator 2 is cantilevered in the shield body 1. Since the vibrator 2 does not significantly affect the vibration operation even if the base 2d is rigidly supported, the support members 4 and 4 are formed of metal, ceramic, or a synthetic resin material, and the base 2d of the vibrator 2 is It can be rigidly fixed to the open end.

However, the support members 4, 4 can be made of an elastic material that can be slightly deformed, such as a resin material or hard rubber. When the support members 4 and 4 are formed of an elastic material, the vibrating pieces 2 a and 2
When the base 2d slightly warps due to the vibrations b and 2c, it can be absorbed by the support members 4 and 4. However, it is necessary that the rigidity of the support members 4 and 4 is high to some extent. When the support members 4 and 4 are made of a very soft material, the vibration of the vibrating reeds 2a, 2b and 2c causes
4, which reduces the accuracy of Coriolis force detection.

The base end 2d of the vibrator 2 is
4, the vibrator 2 is instantaneously greatly deformed when an external impact is applied, and the vibrating reeds 2a, 2b, 2c are impacted on the inner wall surface of the shield body 1. May be hit. In order to eliminate such instability of cantilever support, the middle portion of the vibrator 2 can be supported by soft elastic bodies 5 and 5. The elastic members 5 and 5 are formed of a material having low rigidity so as to support positions of the vibrator 2 deviated from the vibrating bars 2a, 2b and 2c, and not to hinder the vibration of the vibrating bars 2a, 2b and 2c. .

The provision of the elastic members 5, 5 ensures that the vibrator 2 is held in the middle of the inside of the shield body 1 and prevents the vibrating bars 2a, 2b, 2c from hitting the inner wall of the shield body 1. . Further, the elastic members 5 and 5 are
By being formed of a soft material at a position deviating from a, 2b, and 2c, the vibrating operation of the vibrator 2 is not adversely affected.

The protection device for a vibrator according to the present invention shown in FIG. 1 has a structure in which the vibrator 2 is held in a shield body 1 formed by bending a metal plate. . Further, since the vibrator 2 is protected by the shield body 1, the vibrator 2 is hardly damaged by external force. Further, noise caused by ultrasonic waves when the vibrator 2 vibrates can be reliably shielded by the shield body 1.

FIG. 2 shows an example of a structure for supporting the assembly of the shield 1 and the vibrator 2 shown in FIG. 1 on a base. FIGS. 3 to 5 show the support structure shown in FIG. FIG. As shown in FIG. 2, the shield 1 is provided with a support member 4 that supports the vibrator 2 on the side of the bent portion 1 c.
Is preferably supported at point P on the side opposite to the side provided with. The point P is preferably provided on the left side in the figure from the center point of the dimension of the shield body 1 in the Z direction. As shown in FIG. 6, the point P may be provided on the bent portion 1c.

In the case where the point P of the support point of the shield body 1 is provided on the left side in the figure, when vibration or impact is applied from the outside, the shield body 1 uses the point P as a fulcrum, and α1-α2.
Vibrates by deforming in the direction. Further, the vibrator 1 deforms in the β1-β2 direction with the portion of the support member 4 located on the free end side of the shield body 1 as a fulcrum and vibrates. As described above, in the structure in which the shield body 1 deforms and vibrates around the point P and the vibrator 2 further deforms and vibrates around the free end side of the vibration, external vibrations and impacts cause the deformation of the shield body 1. And the deformation of the vibrator 2 and are absorbed. Therefore, the vibrator 2 is less likely to be damaged by an external impact or vibration.

In the vibrator protection device shown in FIG. 3, the shield body 11 is bent into a U shape by a metal plate.
The base 2d of the vibrator 2 is held by the supporting members 4 and 4 at its open end. In this shield body 11, supporting pieces 11 are provided on both sides of a lower metal plate 11c near a folded portion.
a, 11a are formed, and mounting holes 11b, 11b are formed in the support pieces 11a, 11a.

When the mounting holes 11b, 11b are fixed on the base 7 with screws, the support piece 11a becomes a point P in FIG. 2, and when an external impact or vibration is applied, the shield member Numeral 11 deforms with the support piece 11a as a fulcrum. Further, an elastic body 6 is interposed between the base 7 and the bottom surface of the shield body 11. Elastic body 6
Is a flexible elastic body such as rubber, sponge, air cushion, foaming agent and the like. By providing the elastic body 6, the external force acting on the base 7 is absorbed by the elastic body 6, and the vibrator 2 is further protected from external vibration.

In the vibrating body protection device shown in FIG. 4, support pieces 21a, 21a are formed on both sides of a metal plate 21c above a U-shaped shield body 21, and the support pieces 21a, 21a are formed.
Are fixed on the base 7 by the mounting holes 21b, 21b formed in the base. Also in FIG. 4, the support pieces 21a, 21a are at point P in FIG.
It can be deformed using 1a and 21a as fulcrums.

In the vibrating body protection device shown in FIG. 5, the supporting pieces 31a and 31a are provided on both sides of the metal plate 31c on the upper side of the shield body 31 formed in a U-shape, similarly to the device shown in FIG.
a is formed. However, cuts are formed on both sides of the metal plate 31c, and the support pieces 31a, 31a are formed at positions retracted toward the center. Since the support pieces 31a, 31a do not protrude significantly in the width direction, the overall width dimension W can be reduced. In FIG. 5, since the cuts 31d are formed at the base ends of the support pieces 31a, 31a, the support pieces 31a, 31a are formed.
a as a fulcrum P point, as shown in FIG.
1 tends to vibrate in the α1-α2 direction. Therefore, external vibrations and shocks can be absorbed by the shield body 31 and the vibrator 2
The protection function of the is increased.

In the vibrator protection device shown in FIGS. 3 to 5, it can be handled as a chip-shaped component by covering the shield case 11 or 21 or 31 and covering the entire shield case and fixing it to the base 7. It is. In this case, a circuit pattern of a conductor is formed on the surface of the base 7, and the lead wires of the drive electrodes and the detection electrodes provided on the vibrating bars 2 a, 2 b, and 2 c of the vibrator 2 are connected to the circuit pattern on the surface of the base 7 And an electrode is formed on the bottom surface of the base 7 in advance. In this way, the base 7 is placed on a general mother board, the electrodes of the base 7 are soldered to the circuit of the mother board, and the electrodes of the vibrator 2 are conducted to the circuit pattern of the mother board. be able to. It is also possible to mount other electronic circuits, such as a detection circuit of a vibration gyroscope, on the base 7.

When the structure shown in FIGS. 3 to 5 is further surrounded by a shield case, the ultrasonic waves generated by the vibration of the vibrator 2 can be shielded by both the shield body 11, 21, or 31 and the shield case.

FIG. 6 shows a U-shaped shield 4.
An example in which a support piece 41a is formed in one bent portion is shown.
A soft elastic body 6 is installed on a base 7, a shield body 41 is mounted thereon, an elastic body 9 of the same material as the elastic body 6 is installed thereon, and a shield case 10 is further covered. I have. The shield body 41 is held between the base 7 and the ceiling of the shield case 10 by being surrounded by the elastic bodies 6 and 9. And the tip of the support piece 41a
It is fitted in a groove 7 a formed in the substrate 7. In the case shown in FIG. 6, when external vibration or impact is applied, the shield body 41 moves with the support piece 41 a as a fulcrum, but since the upper and lower sides are held by the elastic bodies 6 and 9, it is impossible for the shield body 41. No force acts, and the vibrator 2 is protected.

[0033]

[0034]

According to the present invention, even when external vibration or impact is applied, the vibrator is protected by the shield, and damage to the vibrator can be prevented. When the shield is formed in a U-shape, the manufacture of the shield is easy and the whole can be made thin.

When the shield is supported on the side opposite to the support side of the vibrator, external vibrations or shocks can be absorbed by the deformation of the shield and the deformation of the vibrator, and the protection function of the vibrator can be enhanced.

Further, by storing the shield body incorporating the vibrator in the case together with the elastic body, the shield body can be handled as a chip-shaped component, and the impact resistance can be further increased. Noise such as ultrasonic waves emitted from the antenna can be double shielded.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a basic structure of a vibrating gyroscope vibrator protection device as an example of the present invention;

FIG. 2 is a side view showing a preferred example of a structure supporting the shield body shown in FIG. 1;

FIG. 3 is a side view showing a specific example of the support structure shown in FIG. 2;

FIG. 4 is a side view showing another specific example of the support structure shown in FIG. 2;

FIG. 5 is a side view showing another specific example of the support structure shown in FIG. 2;

FIG. 6 is an exploded perspective view showing another structure of the vibrator protection device;

FIG. 7 shows an example of a vibrator used in a vibratory gyroscope .
Perspective view,

[Explanation of symbols]

 1, 11, 21, 31, 41 Shield 2 Vibrator 2a, 2b, 2c Vibrating reed 2d Base 4 Supporting member 5 Elastic 6,9 Elastic 7 Base 10 Shield case

Continuation of the front page (56) References JP-A-7-243857 (JP, A) JP-A-7-83671 (JP, A) JP-A-51-134094 (JP, A) JP-A-53-6594 (JP) JP-A-52-50190 (JP, A) JP-A-48-47290 (JP, A) JP-A-53-59382 (JP, U) JP-A-48-43370 (JP, Y1) (58) Field surveyed (Int.Cl. ⁷ , DB name) G01C 19/56 G01P 9/04 H03H 9/00-9/76

Claims (5)

(57) [Claims] 1. A protection device in which a vibrator having a plurality of vibrating reeds branched at a tip is incorporated, wherein a supporting portion of the vibrator on which both front and back surfaces of a base where the vibrating reed is not formed is formed of an elastic material. Opened by bending a shield body made of a single metal plate
A vibrator protection device, wherein the base of the vibrator is supported via the support member between the discharge ends . 2. The shield body according to claim 1, wherein the metal plate is folded in a U-shape.
The vibrator protection device according to claim 1, wherein the vibrator is bent . 3. The support member of a vibrator in a shield body.
3. The vibrator protection device according to claim 1, wherein the vibrator is supported and an intermediate portion of the vibrator is elastically supported. 4. The vibrator protection device according to claim 3, wherein the shield body has a portion opposite to the support side of the vibrator supported on a base. 5. An upper and lower shield body is sandwiched between elastic bodies,
5. The vibrator protection device according to claim 1, wherein the shield body and the elastic body are housed in a case.