JP3020496B1 - Anti-vibration device for angular velocity sensor and angular velocity sensor device - Google Patents

Abstract

A vibration isolator holding an angular velocity sensor in a case, wherein a sensitive axis and an elastic coefficient in a direction perpendicular to the sensitive axis can be set independently. SOLUTION: Sensor mounting plates 2 and 3 are mounted on two surfaces perpendicular to a detection axis of an angular velocity sensor 1. Similarly, ring-shaped elastic disks 4 and 5 are attached to the sensor attachment plates 2 and 3, and pipes 6 and 7 are further attached. The pipes 6 and 7 hold an angular velocity sensor in a case 10 using elastic disks 8 and 9 provided outside. In this case, the elastic coefficients of the sensitive axis and the axis perpendicular thereto are determined by the deformation of the elastic disks 4, 5, 8, and 9. Further, the elastic modulus in the direction perpendicular to the sensitive axis can be adjusted by changing the length of the pipes 6,7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity sensor device for use in an automobile navigation system, an automatic steering system, an attitude control of a model helicopter for radio control, and an anti-vibration device therefor.

[0002]

2. Description of the Related Art In a conventional car navigation system, a traveling trajectory of a vehicle is calculated by integrating a speed of the car to obtain a travel distance, integrating a rotational angular velocity, and obtaining an azimuth thereof. In a model helicopter for radio control, the angular velocity around the yaw axis is detected, and the attitude is stabilized by feeding back to the pitch control of the tail rotor. An angular velocity sensor is widely used for these purposes. As such an angular velocity sensor, a piezoelectric gyro utilizing Coriolis force is often used in addition to a gyro conventionally used. The piezoelectric vibration type angular velocity sensor vibrates a vibrator such as a triangular prism, and detects a Coriolis force generated in the vibrator according to the rotational angular velocity during rotation by a detecting piezoelectric element.

When such an angular velocity sensor is affected by external vibration or impact, an erroneous signal may be output. For this reason, it is necessary to support the sensor so that the angular velocity can be accurately detected without being affected by vibration from the vehicle body or the body.

A vibration isolator for an angular velocity sensor needs to be isoelastic and high in rigidity around the sensitive axis of the angular velocity sensor. If the angular velocity sensor is held by the vibration isolating member, the center of gravity moves in accordance with the acceleration, and if it is not elastic with respect to the sensitive axis, a rotation signal from the angular velocity sensor may be generated even if it is a simple reciprocating movement. There is. If the rigidity is low, the angular velocity of the moving body cannot be faithfully transmitted to the angular velocity sensor. Therefore, the angular velocity sensor needs to consider the shape of the vibration isolating member based on these requirements.

[0005] In view of such demands for isoelasticity around the sensitive axis and high rigidity, for example, as shown in FIG. 8, a vibration-type angular velocity sensor 101 is made of a disk-shaped elastic body 102 of a uniform material having an appropriate thickness. An angular velocity sensor device held in a case 103 by a hollow disk-shaped elastic body is used. Hereinafter, this is referred to as a first conventional example. 6-4
As shown in No. 3571, the angular velocity sensor is housed in an elastic body such as silicone resin and fixed in a cylindrical case, and the case is supported on an outer cylindrical housing via a U-shaped vibration-proof rubber. Some suggestions have been made. Hereinafter, this is referred to as a second conventional example.

[0006]

The support by the elastic body shown in the above-mentioned first conventional example has no unnecessary space and is low in cost. However, there are cases where acceleration in the sensitive axis (Z-axis) direction is applied. When an acceleration is applied in a direction (X-axis direction, Y-axis direction) perpendicular to the sensitive axis, the elastic body has a different elastic modulus because the distortion generated in the elastic body is geometrically different. The elastic coefficient K _Z of normal sensitive axis decreases, modulus K _X and K _Y direction perpendicular to the sensitivity axis becomes large. For this reason, it is difficult to change only one of the elastic coefficients in two directions even if the size of the disk-shaped vibration isolating member 102 is changed. That is, when the elastic modulus in the direction perpendicular to the sensitive axis is reduced by changing the dimensions, there is a method of increasing the outer circumference of the disk-shaped vibration isolating member or reducing the thickness thereof. The modulus of elasticity will also be reduced. Further, it is necessary to avoid that the vibration isolating member is deformed due to the weight of the angular velocity sensor in a normal state, and the angular velocity sensor deviates from a proper position. Assuming that a value satisfying this requirement is the lower limit of the elastic modulus, the elastic modulus in the direction perpendicular to the axis may not drop to a predetermined value even if the elastic modulus in the sensitive axis direction has reached the lower limit.

In the second conventional example, the resonance frequency in the direction perpendicular to the sensitive axis is lowered by using a cylindrical case or a silicone resin for supporting the angular velocity sensor in the cylindrical case. As a result, the weight increases, and the moment of inertia about the axis increases, so that the response speed decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and makes the elastic coefficient in the sensitive axis direction and the elastic coefficient around the sensitive axis independent while the angular velocity sensor is held with high rigidity. The purpose is to be able to set.

[0009]

The invention according to claim 1 of the present application is a vibration isolator of an angular velocity sensor for holding an angular velocity sensor in a case, which is provided on a disk portion and an outer peripheral portion of the disk portion. A first ring portion, a second ring portion parallel to the first ring portion, a pair of elastic members having a cylindrical portion connecting an outer periphery of the first ring portion and an inner periphery of the second ring portion, The disk portions of the pair of elastic members are connected symmetrically to two surfaces perpendicular to the angular velocity detection axis of the angular velocity sensor, and the outer peripheral ends of the respective elastic members are held in a case. Things.

According to a second aspect of the present invention, there is provided an anti-vibration device for an angular velocity sensor which holds the angular velocity sensor in a case,
On two surfaces perpendicular to the angular velocity detection axis of the angular velocity sensor, the circular first and second elastic members respectively mounted around the detection axis, the angular velocity detection axis and the axis of the cylinder coincide with each other. First and second cylindrical members having predetermined lengths attached to the outer peripheral portions of the first and second elastic members in different directions from each other, and the angular velocity sensor detection shaft provided on the other end surface of each of the cylindrical members. Ring-shaped third mounted around
And a fourth elastic member, wherein the angular velocity sensor is held by attaching outer peripheral portions of the third and fourth elastic members to a case.

According to a third aspect of the present invention, there is provided a case, an angular velocity sensor, a disk portion, a first ring portion provided on an outer peripheral portion of the disk portion, and a second ring portion parallel to the first ring portion, A pair of elastic members having a cylindrical portion connecting an outer periphery of the first ring portion and an inner periphery of the second ring portion,
The disk portions of the pair of elastic members are connected symmetrically to two surfaces perpendicular to the angular velocity detection axis of the angular velocity sensor, and an outer peripheral end of each elastic member is held in the case. Is what you do.

According to a fourth aspect of the present invention, there are provided first and second circular first and second circular sensors mounted on a case, an angular velocity sensor, and two surfaces perpendicular to an angular velocity detection axis of the angular velocity sensor, respectively, with the detection axis as a center. An elastic member and first and second lengths 1 and 2 attached to outer peripheral portions of the first and second elastic members in directions different from each other such that the angular velocity detection axis and the axis of the cylinder coincide with each other.
A second cylindrical member; ring-shaped third and fourth elastic members attached to the other end surfaces of the respective cylindrical members around the detection shaft of the angular velocity sensor; The outer peripheral portion of the fourth elastic member is attached to the case to hold the angular velocity sensor.

[0013]

FIG. 1 is a sectional view showing the overall configuration of an angular velocity sensor held by a vibration isolator according to a first embodiment of the present invention, and FIG. 2 is an assembly configuration diagram thereof. In the figure, an angular velocity sensor 1 includes an oscillation circuit, a piezoelectric element for vibration, a vibrating body, a piezoelectric element for vibration detection,
An angular velocity sensor that houses a detection circuit, an amplifier, and the like, detects an angular velocity based on a Coriolis force when rotating along a central axis thereof, and outputs a voltage corresponding to the angular velocity. The housing of the angular velocity sensor 1 itself has an electromagnetic shielding function and attenuates acoustic vibrations generated by an internal vibrating body, and has a sound insulating function, and is an essential function in configuring the angular velocity sensor. Is fulfilled.

The upper and lower surfaces of the angular velocity sensor 1 are mounted on sensor mounts 2 and 3 as shown in the figure. The sensor mounts 2 and 3 are hard disks, and are mounted so that the detection axis of the angular velocity sensor 1 is located at the center thereof. It is also assumed that the center of gravity G of the angular velocity sensor 1 is located on this detection axis. An opening is formed at a substantially central portion of the sensor mount 3, and a lead wire is drawn out from the angular velocity sensor 1.

The sensor mounting plates 2 and 3 are coaxially mounted on elastic disks 4 and 5, which are first and second elastic members, respectively. The elastic disks 4 and 5 are circular or annular disks made of an elastic member such as rubber, and the inner peripheral portion thereof is
And 3 respectively. The outer peripheral portions of the elastic disks 4 and 5 are bent outward with respect to the angular velocity sensor 1 as shown, and are connected to pipes 6 and 7. The pipes 6 and 7 are cylindrical members having a fixed length L, and are respectively connected to elastic disks 8 and 9 as third and fourth elastic members on upper and lower surfaces thereof. The outer elastic disks 8 and 9 are also disks made of an elastic member such as a ring-shaped rubber, and the inner peripheral surfaces thereof are bent and connected to the inner peripheral portions of the pipe members 6 and 7. The elastic discs 8, 9 are arranged in parallel with the inner elastic discs 4, 5, and the respective outer peripheral portions are bent downward and upward, respectively. The case of the angular velocity sensor device includes a case body 10, a base 11, and a cylinder 12 having a diameter substantially equal to the inner wall of the case body 10.
The outer peripheral portions of the elastic disks 8 and 9 are folded back along the cylinder 12 as shown in the figure, and are inserted into the case body 10. And it is fitted and fixed on the base 11. The angular velocity sensor device thus configured is attached to a moving body (not shown).

Next, the movement when vibration is applied to the angular velocity sensor device of the present embodiment will be described. First, a coordinate axis fixed to the case body 10 of this device is assumed. The upper part of the paper in the sensitive axis direction passing through the center of gravity G of the angular velocity sensor 1 is defined as the Z-axis direction, the right-hand direction perpendicular to the paper is defined as the X-axis direction, and the back direction perpendicular to the Z-axis and the paper is defined as the Y-axis direction. The origin O of these coordinates is assumed to coincide with the center of gravity G of the angular velocity sensor 1 when the angular velocity sensor device is at rest. The following description will be made ignoring the weights of the sensor mounts 2 and 3, the elastic disks 4, 5, 8, and 9, and the pipes 6 and 7.

First, a case where the entire angular velocity sensor device is accelerated in the Z-axis direction will be described with reference to FIG. FIG. 3 schematically shows the deformation except for the outer case 10 and the base 11. In this case, each elastic disk 4, 5, 8, 9
Is deformed as shown in FIG. When the acceleration in the Z-axis direction is applied in this manner, each elastic disk is deformed as shown in the figure, but the centers of the pipes 6 and 7 do not change in the X-axis or Y-axis direction, and the angular velocity sensor The center of gravity G also moves along the Z axis in the −Z direction according to the acceleration.

Next, a case where the angular velocity sensor device accelerates in the X-axis direction will be described with reference to FIG. In this case, the angular velocity sensor 1 itself moves in the -X direction as shown in FIG. The center of the upper end surface of the pipe 6 and the center of the lower end surface of the pipe 7 hardly change, and these two surfaces are inclined as shown. If the centers of these surfaces move in the -X direction,
Large stress is generated in the external elastic disks 8 and 9. This stress is a tensile stress and a shear stress in the radial direction. On the other hand, when these surfaces are inclined, a tensile stress in the radial direction and a bending stress in the thickness direction are generated. Due to the difference between these stresses, the centers of the upper end face and the lower end face do not move in the -X direction, but are inclined as shown in the figure. The same applies to the inner elastic disks 4 and 5. Since the elastic disks 4 and 5 are attached to the lower end surface and the upper end surface of the pipes 6 and 7, respectively, they move as a whole according to the inclination of the pipe. Is at the center position, and the surfaces of the elastic disks 4 and 5 are inclined. However, since the angular velocity sensor 1 is vertically symmetric with respect to the XY plane, the angular velocity sensor 1 does not tilt in the vertical direction and moves only in the −X axis direction. Assuming that the distance between the center of gravity G of the angular velocity sensor 1 and the origin O at this time is x, the distance x is given by the inclination of the pipes 6 and 7 and the length L thereof. Pipes 6 and 7
Is related only to the deformation of the four elastic disks 4, 5, 8, and 9, and the restoring force F resulting from this deformation is a force that draws the center of gravity G to the coordinate origin O of the case. Therefore, even if the restoring force is the same, the distance x changes depending on the length L of the pipe. The following equation holds between the restoring force F, the elastic coefficient K, and the distance x. F = K _X × x That is, the elastic coefficient K _X can be adjusted by the pipe length L. Although the case where the acceleration acts in the X-axis direction has been described here, since it is axisymmetric about the Z-axis,
The same can be said for the case where an angular velocity is applied in the axial direction or the intermediate direction between the X axis and the Y axis.

Meanwhile modulus K _Z in the Z-axis direction as shown in FIG. 3 is determined only by the properties of the elastic disc 4,5,8,9, also by changing the length L of the pipe 6, 7 Z changes in the axial direction of the elastic coefficient K _Z is not. Therefore it is possible to K _Z determines the diameter and material of the elastic disc 4,5,8,9 to a desired value, then adjust the K _X the length L of the pipe 6 and 7. In this way, the elastic modulus in the Z-axis direction and in the direction perpendicular thereto can be determined independently.

For example, in the case of a radio control helicopter, the harmful vibration frequency is, for example, 40 Hz to 18 Hz.
It is considered that the frequency is 0 Hz, and it is necessary to remove the vibration of 40 Hz or more. In this case 40Hz for vibration in any direction
In order to cut off the above, the resonance frequency in any direction is 4
It must be 0 Hz. The vibration damping device cuts off the vibration frequency higher than the resonance frequency and acts to prevent vibration from being applied to the angular velocity sensor.
Hz. The resonance frequency is the elastic modulus and the mass of the moving part,
That is, it can be calculated from the angular velocity sensor itself and the mass of the sensor mounting base. As described above, in order to obtain a desired vibration frequency cutoff characteristic, by independently selecting the elastic modulus in the X-axis direction and the elastic modulus in the Z-axis direction, it is possible to prevent the characteristic in only one direction from being of excessive quality. . Further, the design becomes easy, and the whole can be reduced in size and weight. Further, since the moment of inertia around the axis can be reduced as compared with the second conventional example, the response speed does not decrease.

FIGS. 5A and 5B are a perspective view and a sectional view showing the configuration of a pipe-shaped member and an external elastic disk according to a second embodiment of the present invention. As shown in this figure, the outer elastic disk is not an annular disk as in the first embodiment, but is curved so as to be connected to the ring 21 from the inner periphery of the ring 21 and the pipe 6. It is configured as an elastic member 22. The members attached below the pipe 7
A similar member is used in place of the elastic disk 9. Other configurations are the same as those of the first embodiment. In this case, similarly to the first embodiment, the elastic modulus in the Z-axis direction and the elastic modulus in the direction perpendicular thereto can be independently selected.

Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, instead of the pipes 6 and 7 of the first embodiment described above, as shown in FIG. And thereby achieve the function of the pipe-shaped member. Further, the pipe member is not limited to a pipe having a constant diameter, but may be a pipe-shaped member 26 having a circular conical shape as shown in FIG. Other configurations are the same as those of the first embodiment.
Also in this case, the elastic modulus in the Z-axis direction and the elastic modulus in the direction perpendicular thereto can be independently selected.

FIG. 7 is a diagram showing a configuration of an angular velocity sensor device according to a fourth embodiment of the present invention. In this embodiment, circular elastic members 31 and 32 having a crank-shaped cross section are provided on the upper surface and the lower surface of the angular velocity sensor 1 as shown in the figure.
Since the elastic members 31 and 32 have the same structure, the elastic member 31 will be described in detail. The elastic member 31 has a circular portion 31a connected to the upper surface of the angular velocity sensor 1 and a flat ring portion 31b on the outer periphery thereof, and further has a cylindrical portion 31c corresponding to the pipe 6 substantially parallel to the axis of the angular velocity sensor. are doing. A ring portion 31d parallel to the ring portion 31b is provided on the outer peripheral portion of the cylindrical portion 31c, and the outer peripheral portion 31e is connected to the case. And this ring part 31b, 31
d, the circular portion 31a and the cylindrical portion 31
c, The thickness of the outer peripheral portion 31e is increased. The circular portions 31a and 32a of these elastic members 31 and 32 are symmetrically connected to the upper and lower surfaces of the angular velocity sensor 1 so as to be centered, and the outer peripheral portion 3
1e and 32e are bonded to the top and bottom of the cylinder 12
The angular velocity sensor device is configured by being housed in the housing 0 and mounted on the base 11.

Even when such elastic members 31, 32 are used, the ring portions 31b, 31d, 32b, 32d have the same functions as the elastic disks 4, 5, 8, 9 of the first embodiment. As a result, the cylindrical portions 31c and 32c can achieve the functions of the pipes 6 and 7. Further, since the angular velocity sensor 1 can be held in the case using only the elastic members 31 and 32, the number of components can be reduced, and the assembling workability can be improved. In this case, the elastic member 31,
32 may be symmetrical with respect to the angular velocity sensor 1 as shown, and may be mounted in the center direction of the angular velocity sensor as shown, or may be mounted so as to be vertically separated as shown in FIG. . When mounted inward in this manner, there is an effect that the case and the whole can be reduced in size.

In this embodiment, the cylindrical portions 31c, 3c
The thickness of the ring portion 2c is larger than that of the ring portions 31b, 31d, 32b, and 32d. However, if the ring portion 2c has a cylindrical shape, it is difficult to be deformed.

In each of the above embodiments, the elastic disk 4,
Although rubber is used as 5, 8, and 9, it is also possible to use a thin plastic member or a thin metal plate. Further, if the angular velocity sensor 1 itself is cylindrical, the sensor mounting plate 2
Except for (3) and (3), the inner peripheral portions of the elastic disks 4 and 5 may be directly attached to the angular velocity sensor 1 with the inner peripheral portions being coaxial.

[0027]

According to the present invention, as described above, the angular velocity sensor can be held in the case via the elastic member. In this case, the elastic coefficients of the angular velocity sensor in the direction of the sensitive axis and in the direction perpendicular thereto can be set independently while maintaining high rigidity, so that the respective elastic coefficients can be set to optimal values. Therefore, it is possible to obtain an effect that the weight can be reduced without excessive quality in the specific direction vibration.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an angular velocity sensor device according to a first embodiment of the present invention.

FIG. 2 is an assembly configuration diagram of the angular velocity sensor device of the present embodiment.

FIG. 3 is a schematic diagram illustrating a deformed state of an internal member when acceleration in the Z-axis direction is applied to the angular velocity sensor according to the present embodiment.

FIG. 4 is a schematic diagram showing a deformation state of an internal member when acceleration is applied to the angular velocity sensor of the present embodiment in an X-axis direction perpendicular to a sensitive axis.

FIG. 5 is a perspective view and a sectional view of an elastic member used in an angular velocity sensor device according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a ring-shaped member according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing a configuration of an angular velocity sensor device according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view showing an example of a conventional angular velocity sensor device.

[Explanation of symbols]

 Reference Signs List 1 angular velocity sensor 2, 3 sensor mounting plate 4, 5 elastic disk 6, 7 pipe 8, 9 elastic disk 10 case body 11 base 12 cylinder 21, 23, 24 ring 22, 31, 32 elastic member 25 connecting member 26 pipe Shaped members 31a, 32a Disk portions 31b, 31d, 32b, 32d Ring portions 31c, 32c Cylindrical portions 31e, 32e Outer peripheral portions

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01C 19/00-19/72 G01P 9/04

Claims (4)

(57) [Claims] 1. An anti-vibration device for an angular velocity sensor holding an angular velocity sensor in a case, comprising: a disk portion; a first ring portion provided on an outer peripheral portion of the disk portion; A pair of elastic members having a cylindrical portion connecting an outer periphery of the first ring portion and an inner periphery of the second ring portion, on two surfaces perpendicular to an angular velocity detection axis of the angular velocity sensor. A vibration isolator for an angular velocity sensor, wherein the disk portions of the pair of elastic members are symmetrically connected to each other, and outer peripheral ends of the respective elastic members are held in a case. 2. An anti-vibration device for an angular velocity sensor which holds an angular velocity sensor in a case, wherein each of the first and second circular first and second circular axes is mounted on two surfaces perpendicular to an angular velocity detection axis of the angular velocity sensor with the detection axis as a center. A second elastic member, first and second fixed-length first and second members attached to outer peripheral portions of the first and second elastic members in different directions so that the angular velocity detection axis and the axis of the cylinder coincide with each other. Ring-shaped third and fourth cylindrical members attached to the other end surfaces of the respective cylindrical members around the detection shaft of the angular velocity sensor.
And an outer peripheral portion of the third and fourth elastic members is attached to a case to hold the angular velocity sensor. 3. A case, an angular velocity sensor, a disk portion, a first ring portion provided on an outer peripheral portion of the disk portion, a second ring portion parallel to the first ring portion, and the first ring portion. A pair of elastic members each having a cylindrical portion connecting an outer periphery and an inner periphery of the second ring portion; and a circle of the pair of elastic members symmetrically on two surfaces perpendicular to an angular velocity detection axis of the angular velocity sensor. An angular velocity sensor device, wherein a plate portion is connected, and an outer peripheral end of each of the elastic members is held in the case. 4. A case, an angular velocity sensor, first and second circular elastic members respectively mounted on two surfaces perpendicular to an angular velocity detection axis of the angular velocity sensor, the detection elastic axes being centers, and the angular velocity detection. A first and second cylindrical members having a predetermined length attached to outer peripheral portions of the first and second elastic members in directions different from each other so that an axis and an axis of the cylinder coincide with each other; Ring-shaped third and fourth rings attached to the other end surface of the cylindrical member around the angular velocity sensor detection axis.
And an elastic member, wherein the angular velocity sensor is held by attaching outer peripheral portions of the third and fourth elastic members to the case.