JPH0786417B2 - Vibrating gyro - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vibration gyro that detects Coriolis force for the purpose of detecting angular velocity.

[Conventional technology]

Conventionally known vibration gyros include, for example, one shown in FIG.

This is two arm members that extend parallel to each other in the Z-axis direction of the three-dimensional coordinate system and are positioned at a predetermined interval in the Y-axis direction.
A drive oscillator 104, which is integrally connected to the lower ends of 101 and 102 by a base portion 103 extending in the Y-axis direction, is fixed to a base 106 via a support member 105, and the drive oscillator 104 is also provided.
The base portion 103 is provided with a detecting means 107 protruding in the X-axis direction.

In such a vibration gyro, for example, each arm member 10
By applying an AC voltage to the driving means 108, 109 provided in 1, 102,
While driving the arm members 101 and 102 to vibrate symmetrically in the Y-axis direction by a piezoelectric method, an electromagnetic method, or the like, the driving vibrator 10
When 4 is rotated around the Z axis at an angular velocity ωz, each arm member 101, 102 moving at a velocity V at a certain moment,
Coriolis forces Fcx that are opposite to each other in the X-axis direction are generated.

Here, since the velocity V of the arm members 101 and 102 changes in an alternating manner, the Coriolis force Fcx is generated in a form modulated by the frequency of the both arm members 101 and 102, and the drive vibrator 104 is moved relative to the base 106 by Z.
This causes torsional vibration about the axis, and the torsional angle is proportional to the Coriolis force Fcx, and thus the angular velocity ωz.

Therefore, in this conventional device, the magnitude of the torsional vibration is
By the detecting means 107 protruding in the X-axis direction, a piezoelectric method,
It is supposed to be detected by an electromagnetic method or the like.For example, in a piezoelectric method using a bimorph element or the like, a torsional vibration is converted into a bending vibration of the detecting means 107, and a charge generated by the bimorph element is converted into a voltage according to the bending amount. Is extracted and detected.

However, in such a conventional technique, the vibration of the arm members 101, 102 is caused by the unbalance of the mass of each arm member 101, 102, the unbalance of the length, etc. of the base portion 103.
Due to causing unnecessary vibration in the Y-axis direction,
Since the detection means 107 also outputs a signal generated by the unnecessary vibration, even if the angular velocity ωz is zero, the state as if the Coriolis force is detected, that is, the offset is set. However, there is a problem that the S / N ratio is generated, and the S / N ratio, and eventually, the detection sensitivity is reduced.

Therefore, in order to solve the problem of the conventional technology, the applicant first proposed as a highly sensitive vibration gyro with an excellent S / N ratio.
As shown in FIG. 9, from the base portion 3 of the drive vibrator 4 to Z
On one side surface of the support member 5 provided so as to project in the axial direction, there is provided a detection means 9 in which an electrode is provided on each of the facing surfaces of the piezoelectric material polarized in the Z-axis direction and orthogonal to the Y-axis. We proposed a vibrating gyroscope which is biased and fixed in the X-axis direction while being in contact with the support member 5 (Japanese Patent Application No. 1-2703).
No. 66).

This vibrating gyro proposed by the applicant prior to this application, as described in the prior art, does not require the detecting means 9 to project from the base portion 3 in the X-axis direction and to the side surface of the supporting member 5. , It can be manufactured by directly joining, therefore the structure of the device can be simplified, the device itself can be made small and inexpensive, and the assembly of the device can be made extremely easy. it can.

Moreover, in such a vibration gyro preceding the present application, the detection means 9 functions to detect the torsion moment Mt acting on the support member 5 due to the generation of the Coriolis force Fcx. However, even if there is an unnecessary vibration in the Y-axis direction in the base portion 3 due to an imbalance in its mass, length, etc., it is necessary to use a special means to prevent the influence from leaking into the detection signal. There is an effect that it can be effectively prevented and the detection sensitivity can be greatly improved.

[Problems to be Solved by the Invention]

However, in the above-mentioned vibrating gyro proposed by the applicant earlier, only the angular velocity ωz around the Z axis can be detected, and the angular velocities around other axes, that is, the vibration directions of the arm members 1 and 2 are detected. Another orthogonal axis: angular velocity ω around the X axis
As for x, it was impossible to detect x despite the generation of Coriolis force Fcz in the Z-axis direction and mutually opposite directions.

Therefore, the present invention aims to provide a vibrating gyroscope capable of simultaneously solving the above-mentioned problems of the conventional technique and the prior proposal technique, and particularly enables advantageous detection of the angular velocity ωx around the X axis. On the other hand, a vibration gyro that can detect a biaxial angular velocity generated in a so-called single drive vibrator by using it in combination with a detection unit for the angular velocity ωz around the Z axis that has already been proposed. Is aimed at.

[Means for Solving the Problems]

As a configuration of a vibrating gyroscope suitable for achieving the above object, the present invention provides two arm members extending in parallel to each other in the Z-axis direction of a three-dimensional coordinate system, and one end portion of each of these arm members. In which a drive vibrator is configured with a base portion integrally connecting the base member and the base member, preferably a central portion thereof, is provided with a support member protruding in the Z-axis direction, and the Y of the support member is provided. At least one side surface orthogonal to the axis is provided with a detecting means constituted by providing electrodes on opposing surfaces orthogonal to the Y axis of a piezoelectric material polarized in the Y axis direction. With respect to the arrangement of the detection means described above, at least one side surface orthogonal to the Z axis and the opposing piezoelectric element polarized in the Z axis direction, which is orthogonal to the Z axis, are arranged on the base portion of the drive vibrator. Electrodes on each side In addition to proposing a vibrating gyroscope in which one of the electrodes is brought into contact with and fixed to a base portion, the sensing means configured and arranged is further proposed, and further, in the base portion of the drive vibrator, preferably in the central portion thereof, A support member protruding in the X-axis direction is provided, and at least one side surface of the support member is provided on each of the opposing surfaces of the piezoelectric material polarized along the X-axis direction, which extends along the support member, parallel to the X-axis. The detecting means including the electrodes is arranged so as to be biased in one of two directions orthogonal to the X axis of the supporting member, and one electrode is brought into contact with and fixed to the supporting member. And at least one side surface of the support member projecting in the X-axis direction, the X-axis of a piezoelectric material extending along the polarization member and polarized in the X-axis direction and substantially in tune with the one side surface. Parallel An electrode is provided on each of the opposing surfaces, and at least one of these electrodes is provided with a detecting means which is divided into two in a direction orthogonal to the X axis, and one of the electrodes is brought into contact with a supporting member. We propose a vibrating gyro, which is fixed by doing so.

[Work]

Now, a tuning fork structure as shown in FIG. 10; that is, two arm members 1 extending parallel to each other in the Z-axis direction of the three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction. , 2 and the base portion 3 integrally connecting the respective one end portions of the arm members 1 and 2 together constitute a drive vibrator 4, and the base portion 3 of the drive vibrator 4 projects in the Z-axis direction. In the tuning fork structure in which the supporting member 5 is provided and fixed to the base 6, the angular velocity ωx around the X axis of this structure will be examined below.

Considering a case where the drive vibrator 4 is rotated around the X axis at an angular velocity ωx while symmetrically vibrating the arm members 1 and 2 in the Y axis direction, each arm member moving at a velocity V at a certain moment. 1,2
In the Z-axis direction, Coriolis forces Fcz in mutually opposite directions are generated. As a result, the drive vibrator 4 is
As shown in FIG. 11, the arm member 1 is pushed down toward the base 6 side based on the Coriolis force Fcz, while the arm member 2 is acted on by the opposite moment separating from the base 6. And pushed up. Therefore, at this time, in the base portion 3, the arm member 1 side and the arm member 2 side are flexibly deformed in the opposite directions of the Z-axis, with the connection portion with the support member 5 as a boundary, and the support member 5 is also Y-shaped. It deforms by bending in the axial direction.

Next, a U-shaped structure as shown in FIG. 12; that is, two arms extending parallel to each other in the Z-axis direction of the three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction. Member 1 ', 2'
And a base portion 3'which integrally connects the respective end portions of these arm members 1 ', 2'to form a drive vibrator 4', and the base portion 3'of the drive vibrator 4'is provided with an X The angular velocity ωx about the X-axis of this structure in a U-shaped structure in which a supporting member 5 ′ projecting in the axial direction is provided and fixed to a base (not shown) will be examined below.

Considering a case where the drive vibrator 4'is rotated around the X axis at an angular velocity ωx while oscillating the arm members 1'and 2'symmetrically in the Y axis direction, the arm is moving at a velocity V at a certain moment. Coriolis forces Fcz in the Z-axis direction and in mutually opposite directions are generated on the arm members 1'and 2 '. As a result, this drive oscillator 4 '
In the same manner as described above, the supporting member 5'protruding in the X-axis direction receives the torsion moment Mt caused by the opposite Coriolis force Fcz generated in each arm member 1 ', 2'. It is twisted and deformed.

As can be seen from the above description, according to the vibrating gyroscope of the present invention, in the structure of the driving vibrators 4 and 4'described above, the X-axis around the X-axis acting on the support member 5 projecting in the Z-axis direction of the base section 3 is acted. Deformation due to the moment of, and the bending deformation due to the moment around the X-axis acting on the base portion 3, or around the X-axis acting on the support member 5'protruding in the X-axis direction of the base portion 3 '. By detecting the torsional deformation due to the moment by providing a detecting means on each of the supporting members 5 and 5 ', it is possible to detect the angular velocity ωx around the X axis which cannot be detected by the known vibration gyro. It is possible.

Now, to the side surface of the support member 5, a detecting means 12 having electrodes 10 and 11 respectively on opposite surfaces of the piezoelectric material polarized in the Y-axis direction on opposite surfaces orthogonal to Y, and either one of the electrodes 10 and 11 is bonded. Then, the detection means 12 has a support member 5 for the detection means 12.
An electric displacement corresponding to the flexural deformation acting on the joint surface is generated.

Further, when one of the electrodes is joined to the side surface of the base portion 3 by a detecting means having electrodes on the opposite surface orthogonal to the Z axis of the piezoelectric material polarized in the Z axis direction, this detecting means is joined. At 12, an electric displacement corresponding to the flexural deformation acting on the joint surface of the base portion 3 is generated.

Furthermore, on the side surface of the supporting member 5 ', a detecting means 12 of a piezoelectric material polarized in the X-axis direction and having electrodes on any opposing surfaces parallel to the X-axis, is provided on the X-axis of the supporting member 5'. When one of the electrodes of the detecting means 12 is joined by being biased in one of the two directions orthogonal to, the detecting means 12 acts on the joint surface of the supporting means 5 '. Generates electrical displacement corresponding to torsional deformation.

Therefore, in the present invention, basically, (a) the detecting means mainly composed of piezoelectric material polarized in the Y-axis direction is provided on at least one side surface of the supporting member 5 orthogonal to the Y-axis. By attaching one of the electrodes provided on the opposing surface orthogonal to the Y axis of 12 so as to be in contact with each other, (b) In addition, the detection means mainly composed of a piezoelectric material polarized in the Z axis direction is used as a base. By mounting one of the electrodes provided on the opposite surface of the detecting means 12 orthogonal to the Z axis to at least one side surface orthogonal to the Z axis of the portion 3, (c) Furthermore, in the X axis direction. When the support member 5'projects in the X-axis direction from the base portion 3 ', the detection means mainly composed of the polarized piezoelectric material is provided on at least one side surface of the support member 5'. Parallel to the axis By mounting the support member in one of two directions orthogonal to the X axis so that one of the electrodes provided on the opposite surface is in contact with each other, the structure is simplified. Realizes a small and inexpensive vibration gyro.

〔Example〕

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

1 (a) and 1 (b) are perspective views showing an embodiment of the present invention, in which the same parts as those described in the prior art are designated by the same numbers.

That is, reference numerals 1 and 2 respectively denote arm members that extend in parallel to each other in the Z-axis direction and are positioned at a predetermined distance in the Y-axis direction, and 3 denotes those arm members 1 and 2. Shows the base parts integrally connected at the lower end. In addition, 4 is
Shows a drive vibrator composed of arm members 1 and 2 and a base portion 3,
The drive vibrator 4 is fixed to the base 6 by a support member 5 protruding from the base portion 3 in the Z-axis direction.

Here, in this example, a vibrating gyro is configured by joining the detection means 12 to one side surface of the support member 5 orthogonal to the Y axis in a posture in which the one electrode 10 is in contact.

In the vibrating gyroscope of this example, the detecting means 12 is made of a piezoelectric material 15 polarized in the Y-axis direction, as shown by an outline arrow in the figure, and has electrodes on opposite surfaces orthogonal to the Y-axis.
According to this, when the bending as shown in FIG. 11 occurs in the supporting member 5, it acts as expansion and contraction on the piezoelectric material attached to it.
A voltage associated with the Coriolis force Fcz is generated between the electrodes 10 and 11.

That is, when the arm members 1 and 2 are vibrated symmetrically in the Y-axis direction by applying an AC voltage to the driving means 13 and 14, the vibrating gyro is rotated about the X-axis at an angular velocity ω, the detection means 12
Can detect the torsion moment Mt acting on the support member 5 based on the Coriolis force Fcz.

In addition, in the vibrating gyro shown in FIG.
The 1, 2, the base portion 3 and the support member 5 do not necessarily have to be an integral structure, and may be configured to be interconnectable.

2 (a) and 2 (b) are schematic diagrams showing another embodiment of the vibrating gyroscope of the present invention, in which the support member 5 is made of a plate-shaped material and , A vibration gyro having detection means 12 and 12a mounted on both surfaces orthogonal to the Y axis. Here, the detection means 12 and 12a are made of a piezoelectric material 15 polarized in the Y-axis direction, and constitute a bimorph in which electrodes 10, 11, 10a and 11a are provided on opposing surfaces orthogonal to the Y-axis. .

Next, FIG. 3 shows still another embodiment: an example of a vibrating gyroscope in which the detecting means 12 is joined to at least one side surface of the base portion 3 orthogonal to the Z axis. The detection means 12 used in this example is made of a piezoelectric material 15 polarized in the Z-axis direction as shown by the white arrow in the figure, and electrodes (not shown) are provided on the opposing surfaces orthogonal to the Z-axis. Is configured,
Since a voltage associated with the Coriolis force Fcz is generated between these electrodes, it functions in the same manner as shown in each of Figs. In this case, it should be noted that since the base portion 3 bends in the opposite direction with the support member 5 as a boundary, the detecting means 12 needs to be biased to one side in the Y-axis direction and joined.

Further, FIG. 4 is a diagram showing an application example of the example of FIG.
Of at least one side surface of the base portion 3 orthogonal to the Z axis,
Both are examples in which two detecting means 12 and 12 'which are located on one side in the Y-axis direction are fixed. However, as described above, in consideration of the fact that both ends of the base portion 3 of the drive vibrator 4 bend in opposite directions with the support member 5 as a boundary, the following arrangement of detecting means is required. is there.

That is, in this example, the respective detection means 12 and 12 'are
The center of it is roughly divided by the XY plane, and Z
It is composed of two piezoelectric materials configured so that the directions of polarization in the axial direction are reversed to each other, and as described above,
Electrodes (not shown) are provided on opposing surfaces of the piezoelectric material that are orthogonal to the Z axis.

Next, FIG. 5 is a view of a vibrating gyroscope showing still another embodiment. In this example, the support member 5 is provided so as to project from the base portion 3 in the X-axis direction and is fixed to a base (not shown). This drive gyro is illustrated on one of the side surfaces of the support member 5 projecting in the X-axis direction, which is orthogonal to the Y-axis, and on the opposing surface of the piezoelectric material polarized in the X-axis direction, which is orthogonal to the Y-axis. This is a vibrating gyroscope configured by biasing and fixing the detection means 12 provided with the omitted electrodes in the Z-axis direction. In this example, as described above, the torsional moment generated in the support member 5 acts on the piezoelectric material as a “shear”, and therefore a voltage associated with the Coriolis force Fcz is generated between the electrodes attached to the detection means. Like

Further, FIG. 6 is a diagram of a vibrating gyro that is an embodiment of the same type as FIG. That is, in this example, the support member 5 protruding from the base portion 3 in the X-axis direction and fixed to a base (not shown) is made of a plate-shaped material, and the support member 5 is opposed to the Y-axis at a right angle. This is a type in which detection means 12, 12 'each having an electrode (not shown) are provided on the surface.

The detection means 12 in this example extends along the plate-shaped supporting member 5 and polarizes the piezoelectric material having a width substantially equal to that of the supporting member in the X-axis direction, and
Where electrodes are provided on opposing surfaces orthogonal to the Y axis, at least one of these electrodes is a small electrode that is divided into two by a virtual plane orthogonal to the electrode surface and parallel to the X axis. It is configured. The appearance of this detection means 12 is similar to that of a bimorph in which an elastic plate is sandwiched by general thickness vibrators, and thus it can be made to function in the same manner as shown in FIG. 1 against the generation of Coriolis force Fcz. it can.

Now, FIG. 7 is a diagram showing an application example of the present invention.
The vibration gyro of the embodiment illustrated in the figure and the conventional detecting means 11 for the angular velocity ωz about the Z axis are both attached, and an example of biaxial angular velocity detection is shown.

Further, FIG. 8 is a diagram showing another application example of the present invention similarly to FIG. 7, and in this case, an H-shaped drive which is a modification of the U-shaped drive vibrator described so far. An example applied to a vibrator is shown. In the vibration gyro of this example, as in the embodiment shown in FIG. 1, the detection means 12 is provided on one side surface of the support member 5 and the Coriolis force Fcx generated with the angular velocity ωz around the Z axis is provided. Support member 5 according to
2 shows an example in which the angular velocity in the biaxial directions can be detected by additionally using the detecting means 16 for detecting the twist around the Z axis.

〔The invention's effect〕

Thus, according to the present invention, as is apparent from the above, by surface-bonding the detection means to the support member, the mechanical strength of the detection means is increased and damage to the detection means due to impact or the like is prevented. You can

Further, according to the present invention, it is possible to detect an angular velocity around the X axis, which has not been conventionally done, and this corresponds to a vibrating gyro for two units with a simple structure by a single driving vibrator. It is also possible to add a biaxial direction detection function.

[Brief description of drawings]

1 (a) and 1 (b) are perspective views of an embodiment of a vibrating gyroscope and a detecting means of the present invention, and FIGS. 2 (a) and 2 (b) are other vibrating gyroscopes of the present invention. FIG. 3 is a front view of another embodiment of the present invention, FIG. 4 is a front view of another embodiment of the present invention, and FIG. 5 is another view of the present invention. 6 is a front view of another embodiment of the present invention, FIG. 7 is a front view showing a biaxial application example of the present invention, and FIG. 8 is a front view of the present invention. FIG. 9 is a front view showing a shaft type application example, FIG. 9 is a view showing a conventional example, FIGS. 10 to 12 are explanatory views for explaining the operating principle of the present invention, and FIG. It is a perspective view of the vibration gyro which concerns on a proposal. 1,2 ... arm member, 3 ... base part, 4 ... driving vibrator, 5 ... support member, 6 ... base, 12 ... detecting means, 10,10a, 11,11a ... electrode, 13 ... Piezoelectric material.

Claims (5)

[Claims] 1. Two arm members extending parallel to each other in the Z-axis direction of a three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction, and one end portion of each of these arm members. In a vibration gyro that detects the angular velocity around the X axis of a drive vibrator that is composed of a base unit that is integrally connected, a support member that projects in the Z axis direction is provided on the base unit of the drive vibrator. At least one side surface of the member that is orthogonal to the Y axis is provided with a detection means that is provided with electrodes on opposite surfaces of the piezoelectric material polarized in the Y axis direction that are orthogonal to the Y axis. A vibration gyro which is fixed by fixing the support member so that the bending deformation of the support member in the YZ plane can be detected. 2. Two arm members extending parallel to each other in the Z-axis direction of the three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction, and one end portion of each of these arm members. In a vibrating gyroscope for detecting an angular velocity around an X axis of a drive vibrator configured with an integrally connected base portion, a support member protruding in the Z axis direction is provided on the base portion of the drive vibrator. An electrode is provided on each of the opposite sides of the piezoelectric material polarized in the Z-axis direction, which are opposed to each other in the Y-axis direction, at a position deviated in the Y-axis direction on at least one side surface of the base section orthogonal to the Z-axis. A vibrating gyroscope in which one of the electrodes is fixed by bringing one of the electrodes into contact with the base portion to detect the flexural deformation of the base portion in the YZ plane. 3. Two arm members extending parallel to each other in the Z-axis direction of the three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction, and one end portion of each of these arm members. In a vibrating gyroscope for detecting an angular velocity around an X axis of a drive vibrator configured with a base unit integrally connected, a support member protruding in the X axis direction is provided on the base unit of the drive vibrator. Supporting means is provided on at least one side surface of the supporting member, the detecting means comprising electrodes provided on the opposite surfaces of the piezoelectric material polarized along the X-axis direction extending in parallel with the X-axis. The vibrating gyroscope, which is arranged so as to be biased in one of two directions orthogonal to the X axis, and in which one electrode is brought into contact with and fixed to a supporting member. 4. Two arm members extending parallel to each other in the Z-axis direction of the three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction, and one end of each of these arm members. In a vibrating gyroscope for detecting an angular velocity around an X axis of a drive vibrator configured with a base portion integrally connected, a support member protruding in the X axis direction is provided on the base portion of the drive vibrator. An electrode is provided on at least one side surface of the support member, and on each of the opposing surfaces parallel to the X axis of the piezoelectric material, which extends along the support member and is polarized in the X axis direction and has substantially the same width as the one side surface. By disposing at least one of these electrodes and dividing the detection surface by a virtual plane that is orthogonal to the electrode surface and parallel to the X-axis, one electrode is brought into contact with the support member. Fix and twist deformation of the support member around the X axis Vibration gyro made in the manner allowed to detection. 5. Two arm members extending parallel to each other in the Z-axis direction of the three-dimensional coordinate system and positioned at a predetermined interval in the Y-axis direction, and one end portion of each of these arm members are provided. A vibrating gyroscope for detecting an angular velocity around an X-axis of a drive vibrator configured with a base unit integrally connected, wherein a base member of the drive vibrator is provided with a support member protruding in a Z-axis direction. On at least one side surface of the part orthogonal to the Z axis,
One of the detection means, which is provided with electrodes on opposite surfaces orthogonal to the Z-axis, of the piezoelectric material, which is divided by the XZ plane and whose polarization directions in the Z-axis direction are inverted to each other, is provided on one side of the Y-axis direction. A vibrating gyroscope in which one electrode of the base portion is brought into contact with and fixed to a base portion at a biased position to detect a flexural deformation of the base portion in the YZ plane.