JPH08159775A - Vibration gyroscope - Google Patents

Abstract

PURPOSE: To provide a vibration gyroscope having a supporting structure, which can prevent the leaking of the vibration from a vibrator, maintains the vibration absorbing effect without obstructing the vibration, and can prevent the deformation caused by excessive shock from the outside. CONSTITUTION: This gyroscope has a columnar vibrator 2, a driving means and a detecting means, which are provided on the side surface of the vibrator 2, supporting members 4, which are formed out of plate materials in an approximately frame shape and support the vicinities of the node points of the vibrator 2 at the inner peripheral part, a holding substrate 6, which has supporting pieces 9 on both sides of the vibrator 2 in the width direction, and linking parts 5 and 5 for linking the supporting members 4 and the supporting pieces 9 of the holding substrate 6. The linking parts 5 and 5 are located on a straight line, which passes the center of gravity of the cross section in the vicinity of the node point of the vibrator 2 and is orthogonal to the bending vibration direction of the vibrator 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration gyro, and more particularly to, for example, a navigation system which detects the position of a moving body by detecting a rotational angular velocity and performs appropriate guidance, or an external vibration which is detected by an appropriate vibration. The present invention relates to a vibration gyro that can be applied to a vibration isolation system such as a shake prevention device for damping vibration.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view showing an example of a conventional vibrating gyro, which is the background of the present invention, and FIG. 8 is a front view thereof. The vibration gyro 21 includes a vibrator 22. The vibrator 22 is made of a constant elastic metal such as elinvar, and is formed in a substantially regular triangular prism shape. On the three sides of the oscillator 22,
Piezoelectric elements 23a, 23b and 23c are formed, respectively. The piezoelectric elements 23a, 23b, 23c are, for example, piezoelectric ceramics with electrodes formed on both sides. And
The piezoelectric elements 23a, 23b, 23c are adhered to the side surface of the vibrator 22, and two of the piezoelectric elements 23a, 23b
b is used for driving and detecting an output signal. The other piezoelectric element 23c is used for feedback.

The vibrator 22 is supported by the support members 24, 24 at the ridgeline portion near its node point. The support member 24 is
A thin wire material having a high elastic modulus made of tungsten or the like is formed in a substantially U-shape. The support member 24 is
It is fixed to the holding substrate 25.

In the vibrating gyro 21, the piezoelectric element 23
An oscillation circuit (not shown) or the like is connected as a feedback loop for self-excited oscillation between the piezoelectric elements 23c and a and 23b. Then, by the drive signal from the oscillation circuit,
The vibrator 22 causes bending vibration mainly perpendicular to the surface on which the piezoelectric element 23c is formed. When rotation about the axis of the vibrator 22 is applied in this state, the vibration direction of the vibrator 22 changes due to the Coriolis force, and an output difference occurs between the piezoelectric elements 23a and 23b. By measuring the output difference, the oscillator 2
The rotational angular velocity added to 2 can be detected.

Here, the support member 24 is formed of a thin wire having a high elastic modulus so that the vibration of the vibrator 22 does not leak to the holding substrate 25 and the vibration of the vibrator is not hindered. Is to get.

[0006]

However, in such a conventional vibrating gyroscope 21, when an excessive impact is applied from the outside, the supporting member 24 is deformed because it is made of a thin wire,
As a result, a predetermined vibration cannot be obtained, and there is a possibility that characteristic deterioration or erroneous detection may occur.

Therefore, a main object of the present invention is to provide a vibrating gyroscope having a support structure capable of preventing deformation due to excessive impact from the outside while maintaining a vibration absorbing effect which is the same as that of a conventional vibrator support structure. It is to be.

[0008]

In order to achieve the above-mentioned object, the present invention provides a columnar vibrator, a driving means and a detecting means provided on the side surface of the vibrator, and a plate material in a substantially frame shape. A support member formed to support the vicinity of the node point of the vibrator at the inner peripheral edge, a holding substrate having support pieces on both sides in the width direction of the vibrator, and the support member and the support piece of the holding substrate are connected. And a connecting part that passes through the center of gravity of the cross section near the node point of the vibrator and is located on a straight line that is perpendicular to the bending vibration direction of the vibrator.

[0009]

According to the above construction, since the supporting member is formed of the plate material, it is possible to prevent the deformation due to the excessive impact from the outside. Further, since the connecting portion between the supporting member and the supporting piece of the holding substrate passes through the center of gravity of the cross section near the node point of the oscillator and is located on a straight line perpendicular to the bending vibration direction of the oscillator, It is possible to minimize vibration of the vibrator that is transmitted to the support piece through the connecting portion.
Further, the vibration transmitted to the support piece can be absorbed as the bending vibration of the support piece.

[0010]

1 is a perspective view of a vibrating gyroscope showing an embodiment of the present invention, and FIG. 2 is a front view thereof. The vibration gyro 1 includes a vibrator 2. The vibrator 2 is made of, for example, a constant elastic metal such as elinvar, or a material that generally causes mechanical vibration such as quartz, glass, crystal, or ceramic, and is formed in a substantially equilateral triangular prism shape.

Piezoelectric elements 3a, 3b and 3c as driving means and detecting means are formed on the three side surfaces of the vibrator 2, respectively. The piezoelectric elements 3a, 3b, 3c are formed by forming electrodes on both sides of a piezoelectric ceramic, for example, and one of these electrodes is bonded to the side surface of the vibrator 2 with an adhesive or the like. Among them, the piezoelectric elements 3a and 3b are used for driving and detecting an output signal, and the piezoelectric element 3c is used for feedback. An oscillation circuit (not shown) or the like is connected between the piezoelectric elements 3a and 3b and the piezoelectric element 3c as a feedback loop for self-excited driving.

The vibrator 2 is made of a plate material and is supported by frame-shaped support members 4 and 4 having a substantially square V shape. Support member 4
Substantially strip-shaped connecting portions 5 and 5 are provided near the centers of both sides of the outer peripheral edge of the support member 4, and the supporting member 4 and the connecting portions 5 and 5 etch plate materials such as Fe-Ni alloys and constant elastic ropes. It is integrally molded by this. Then, the ridge line portion near the node point of the vibrator 2 is joined to the central portion of the upper side of the inner peripheral edge portion of the support member 4 by spot welding, laser welding, soldering, silver brazing, etc. , 5 pass through the center of gravity 2G of the cross section near the node point of the vibrator 2 and are located on a straight line perpendicular to the bending vibration direction of the vibrator 2. Here, the thickness of the plate member of the support member 4 is
It is desirable that the width is about 0.1 to 1 mm, and the width of the supporting member 4 is sufficiently larger than the thickness of the plate material.

Although the support member 4 has a substantially square frame shape, it may have a trapezoidal or elliptical frame shape. The support member 4 can also be used as a passage for a wire connecting the piezoelectric elements 3a, 3b, 3c and the oscillation circuit.

The support member 4 is held by a holding substrate 6 having a substantially rectangular shape. The holding substrate 6 is made of a Fe—Ni alloy, and is provided with wall portions 7, 7 standing upright on both side edges in the width direction.
It is formed so that the lower part of the support member 4 can be sufficiently accommodated between the seven. And shake. The support member 4 is arranged so that the axial direction of the moving element 2 is parallel to the longitudinal direction of the holding substrate 6.
The connecting portions 5 and 5 provided on the outer peripheral edge of the
The upper surface of 7 is joined by spot welding, laser welding, soldering, silver brazing, or the like. Here, the wall portion 7 and the connecting portion 5
Slits 8 and 8 are formed on both sides of the joint portion from the upper surface of the wall portion 7 downward, and a support piece 9 is formed between the slits 8 and 8. As a result, the support member 4 is connected to the connecting portions 5 and 5.
Will be supported by the support pieces 9, 9.

In the above-described embodiment, the supporting piece 9 is formed by cutting the slits 8 on both sides of the joint portion between the wall portion 7 and the connecting portion 5, but as shown in FIG. A cutout portion 11 may be provided from the central portion of the portion 7 to the vicinity of the joint portion between the wall portion 7 and the connecting portion 5, and the support piece 9 may be formed by the cutout portion 11 and one slit 8. As shown, the support piece 9 may be independently provided on both side edges in the width direction of the holding substrate 6 by cutting out the end side of the wall portion 7, and any means may be used to form the support piece 9. Good. Further, as shown in FIGS. 5 and 6, the connecting portions 5 and 5 are bent toward the central portion side of the holding substrate 6, and the supporting member 4 is formed among the slits 8 and 8 forming the supporting piece 9. The supporting structure may be such that it is housed in one of the slits 8 on the end side in the longitudinal direction of 6, and this supporting structure can reduce the width of the holding substrate 6. Further, the holding substrate 6 is Fe-
Instead of the Ni alloy, a non-ferrous metal such as aluminum or brass, a glass epoxy material, a ceramic material such as alumina, or a glass material may be used.

In the vibrating gyro 1 as described above, the vibrator 2 flexurally vibrates in the direction perpendicular to the surface on which the piezoelectric element 3c is formed by the drive signal from the oscillation circuit. When rotation about the axis of the vibrator 2 is applied in this state, the vibration direction of the vibrator 2 is changed by the Coriolis force, and an output difference occurs between the piezoelectric elements 3a and 3b. By measuring the output difference, the rotational angular velocity applied to the vibrator 2 can be detected.

Further, in the vibrating gyroscope 1 of this embodiment, since the supporting member 4 is formed by integrally molding a plate material, no deformation of the supporting member 4 is recognized even if a shock resistance test of 1 m drop is performed.
The support structure is much stronger than before.

Next, the operation of the vibration gyro 1 according to this embodiment for preventing the vibration of the vibrator 2 from being disturbed and preventing the vibration from leaking to the holding substrate 6 will be described.

The X axis of the three-dimensional coordinate axis is perpendicular to the side surface of the vibrator 2 including the piezoelectric element 3c, the Y axis is horizontal to the side surface of the vibrator 2 including the piezoelectric element 3c, and the Z axis is of the vibrator 2. Take in the axial direction. Then, the bending vibration of the oscillator 2 is
The bending vibration in the axial direction (hereinafter, referred to as Fx mode) and the bending vibration in the Y axis direction (hereinafter, referred to as Fy mode) will be considered.

First, since the connecting portions 5 and 5 pass through the center of gravity 2G of the cross section near the node point of the vibrator 2 and are located on a straight line perpendicular to the bending vibration direction of the vibrator 2,
Vibrations of the vibrator 2 in the Fx mode and the Fy mode transmitted from the support member 4 to the support pieces 9 and 9 via the connecting portions 5 and 5 are minimized.

For the Fx mode vibration, the supporting member 4
Receives translational kinetic energy in the X-axis direction and rotational kinetic energy about the Y-axis passing through the connecting portions 5 and 5. The vibration of the supporting member 4 due to the translational kinetic energy in the X-axis direction is converged on the connecting portions 5 and 5, and is absorbed as the bending vibration of the supporting pieces 9 and 9 of the holding substrate 6. Vibrations of the support member 4 due to rotational kinetic energy around the Y-axis are also absorbed as bending vibrations of the support pieces 9 and 9 by forming nodes at the connecting portions 5 and 5.

On the other hand, with respect to the Fy mode vibration, the support member 4 has the translational kinetic energy in the Y-axis direction and
And rotational kinetic energy about the X axis passing through the junction point 10 of the oscillator 2. The vibration of the support member 4 due to the translational kinetic energy in the Y-axis direction converges on the connecting portions 5 and 5, and is absorbed as the bending vibration of the support pieces 9 and 9. The vibration of the support member 4 due to the rotational kinetic energy around the X axis also causes
A node is formed by 0, converges on the connecting portions 5 and 5, and the supporting pieces 9 and 9 are formed.
Is absorbed as the bending vibration of.

Thus, the Fx mode and F of the vibrator 2 are
By absorbing the y-mode vibration as the bending vibration of the support pieces 9 and 9, the vibration of the vibrator 2 is not hindered and the vibration absorption effect to the holding substrate 6 is very small.

Next, in order to confirm the vibration absorbing effect of the support structure of the present embodiment, the depth of the slits 8 of the wall portion 7 is changed to change the vibration machine of the Fx mode and the Fy mode of the vibrator 2. The experimental result which measured the static quality factor (henceforth Qm) is shown.

In this experiment, the length of the side of the outer peripheral edge of the supporting member 4 having the connecting portions 5 and 5 at the center is L, and the depth of the slits 8 and 8 is L. It is expressed by the ratio of.

First, under condition 1, the depth of the slits 8, 8 was 0.2 L. Under the condition 2, the depth of the slits 8, 8 was 0.4L. Under the condition 3, the depth of the slits 8, 8 was 0.5L. In Condition 4, the slits 8 and 8 were not provided as a comparative example.

Under the conditions 1 to 4, the results of measuring the Qm of the Fx mode and Fy mode vibrations of the vibrator 2 and the Fx mode of the vibrator 2 in the case of using the conventional support structure using the wire rod as a comparative example Table 1 shows the Qm of vibrations in the Fy mode and the Fy mode.

[0028]

[Table 1]

As shown in Table 1, in this experiment, the conventional wire rod was used for the Qm of vibrations in the Fx mode and the Fy mode under the condition 3 in which the depth of the slits 8, 8 was 0.5 L. It showed a good value that was no different from the vibration gyro of the support structure. In particular, the Qm of vibration in the Fx mode became better as the slits 8 were deepened.

From this experiment, by adjusting the depths of the slits 8 and 8 so that the flexural vibration of the support piece 9 can be sufficiently obtained, the Qm of the Fx mode and Fy mode vibrations can be compared with the conventional vibration gyro. It was confirmed that the value could not change. In addition, as a result of separately measuring the temperature characteristics of the output voltage of the vibrator 2 at rest with the support structure as in Condition 3, -3
It was confirmed to be as good as 100 mV / ° C. or less in the range of 0 ° C. to 85 ° C. These two measurement results are shown in Condition 3
It is shown that the above supporting structure does not hinder the vibration of the vibrator 2 as in the conventional case and prevents the leakage of the vibration to the holding substrate 6.

[0031]

As described above, according to the vibrating gyroscope of the present invention, since the supporting member is made of the plate material, it is possible to prevent the deformation due to the excessive impact from the outside. Further, the connecting portion between the supporting member and the holding substrate is supported by a supporting piece provided on the holding substrate, the connecting portion passes through the center of gravity of the cross section near the node point of the vibrator, and is perpendicular to the bending vibration direction of the vibrator. By locating on a straight line,
It is possible to minimize the vibration transmitted from the supporting member to the supporting piece of the holding substrate via the connecting portion. Further, the vibration transmitted to the support piece can be absorbed as the bending vibration of the support piece. As a result, it is possible to prevent vibration from leaking to the holding substrate, obtain a good vibration absorption effect that does not hinder the vibration of the vibrator, and provide a vibration gyro with excellent vibration resistance and shock resistance.

[Brief description of drawings]

FIG. 1 is a perspective view showing a vibrating gyroscope according to an embodiment of the present invention.

FIG. 2 is a front view of the vibrating gyro shown in FIG.

FIG. 3 is a perspective view showing a modified example of a support member of the vibration gyro shown in FIG.

FIG. 4 is a perspective view showing another modified example of the support member of the vibration gyro shown in FIG.

5 is a side view showing still another modified example of the supporting member of the vibration gyro shown in FIG. 1. FIG.

FIG. 6 is a front view of the vibrating gyro shown in FIG.

FIG. 7 is a perspective view showing a conventional vibrating gyro.

8 is a front view of the vibrating gyro shown in FIG. 7. FIG.

[Explanation of symbols]

 1 Vibration Gyro 2 Vibrator 3a Piezoelectric element 3b Piezoelectric element 3c Piezoelectric element 4 Supporting member 5 Connecting part 6 Holding substrate 7 Wall part 8 Slit 9 Supporting piece 10 Joining point

Claims (1)

[Claims] 1. A column-shaped vibrator, a driving means and a detection means provided on a side surface of the vibrator, and a plate-like member formed in a substantially frame shape, and an inner peripheral edge portion thereof supports a vicinity of a node point of the vibrator. A supporting member, a holding substrate having supporting pieces on both sides in the width direction of the vibrator, and a connecting portion connecting the supporting member and the supporting piece of the holding substrate, the connecting portion being a node point of the vibrator. A vibrating gyro, wherein the vibrating gyro is located on a straight line that passes through the center of gravity of a nearby cross section and is perpendicular to the bending vibration direction of the vibrator.