JP3282442B2 - Vibrating gyro - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope,
Especially, for example, a vibration gyro that can be applied to a navigation system that detects the position of a moving object by detecting angular velocity and performs appropriate guidance, or a yaw rate sensor that detects external vibration and performs appropriate vibration suppression. is there.

[0002]

2. Description of the Related Art FIG. 7A is a perspective view showing an example of a conventional vibrating gyroscope, and FIG. 7B is a sectional view thereof.
FIG. 8 is an illustrative view showing a state in which the vibrating gyroscope shown in FIG. 7 is bending vibrating. The vibrating gyroscope 1 includes a vibrator 2, and the vibrator 2 includes a vibrating body 3. The vibrating body 3 is formed in a regular triangular prism shape using, for example, a constant elastic metal material. Piezoelectric elements 4a, 4b, 4c are formed on three side surfaces of the vibrating body 3, respectively. Each of the piezoelectric elements 4a, 4b, and 4c includes a piezoelectric layer 5 made of porcelain or the like. Then, electrodes 6 are formed on both surfaces of the piezoelectric layer 5. One of these electrodes 6 is adhered to the vibrating body 3. Further, a support member 7 is fixed to a ridge portion near the node point of the vibrating body 3. Support member 7
Is formed of, for example, a metal wire, and is fixed to the vibrating body 3 by welding or the like. The support member 7 is formed in a U-shape, and both ends of the support member 7 are attached to a support base 8 or the like.

In this vibrating gyroscope 1, a piezoelectric element 4a,
An oscillation circuit is connected between 4b and the piezoelectric element 4c. With this oscillation circuit, the vibrating body 3 bends and vibrates in a direction orthogonal to the surface on which the piezoelectric element 4c is formed. In this state, when the vibrating body 3 rotates about the central axis, the direction of the bending vibration changes due to the Coriolis force. Thereby, the piezoelectric elements 4a,
4b produces a difference. Therefore, the piezoelectric element 4
By measuring the difference between the output signals a and 4b, the rotational angular velocity can be detected.

[0004]

In the conventional vibrating gyroscope 1 as shown in FIG. 7, the vibrating body 3 is formed of a regular triangular prism-shaped sound piece, and flexurally vibrates at a node of free vibration of the vibrating body 3. . In this case, as shown in FIG. 8, the vibrating body 3 bends and vibrates around two node points. When the length of the vibrating body 3 is L, the nodal points of the vibrating body 3 are 0.1 mm from both ends. 2
It is on the center line at the position 24L. Further, the displacement due to the Coriolis force generated when the vibrating body 3 rotates around its central axis occurs in a direction orthogonal to the displacement of the free vibration of the vibrating body 3. Furthermore, the sensitivity of the vibrating gyroscope 1 is enhanced by maintaining a high degree of freedom in the support structure of the vibrating body 3 in the two directions orthogonal to each other.

For a series of these reasons, in the conventional vibrating gyroscope 1 shown in FIG. 7, as a structure for supporting the vibrating body 3, the vibrating body 3 has a high degree of freedom as much as possible. The middle part of the U-shaped support member 7 made of a metal wire is fixed to the ridge near the node point by welding or the like, and both ends of the support member 7 are fixed to the support 8 in a three-dimensional manner. It constitutes a complex support structure.
In this case, the vibrating body 3 is supported by the support member 7 at two node points on both sides in the longitudinal direction.

In the conventional vibrating gyroscope 1 shown in FIG. 7, since the U-shaped supporting member 7 is bulky, the miniaturization of the vibrating gyroscope is hindered, and the vibrating gyroscope is prepared by using the separately prepared supporting member 7 and supporting stand 8. In order to support the body 3, their material costs and their assembling costs are also high, which hinders a reduction in manufacturing costs. In the conventional vibrating gyroscope 1 under such circumstances, it is conceivable to reduce the overall length L of the vibrating body 3 in order to reduce the size. Since the amplitude of the free vibration of the body 3 decreases, the frequency increases. Therefore, even if the vibrating gyroscope is reduced in size, the sensitivity of the vibrating gyroscope 1 is reduced, causing a problem. Conversely, in order to increase the sensitivity of the vibrating gyroscope 1, it is necessary to increase the total length L of the vibrating body 3 in order to increase the amplitude of free vibration of the vibrating body 3. Will do.

Therefore, when the entire length L of the vibrating body 3 is the same, the frequency is reduced, and the sensitivity of the vibrating gyroscope can be increased. When the frequency of the vibrating body 3 at the time of free vibration is the same, Therefore, there is a need for a vibrating gyroscope having a vibration mode in which the overall length L can be shortened and the size can be reduced.

Therefore, a main object of the present invention is to provide a vibrating gyroscope which can be manufactured easily, has high sensitivity and can be miniaturized.

[0009]

SUMMARY OF THE INVENTION The present invention includes a vibrating body having a cylindrical hollow portion and performing bending vibration and a supporting portion for supporting the vibrating body at an axial end of the vibrating body. The body and the support are integrally formed by subjecting the pre-processed material to drawing, and the vibrating body is a vibrating gyroscope that is cantilevered by the support. The vibrating body may be formed in a bottomed cylindrical shape. The vibration body may be formed in a polygonal cylindrical shape. Furthermore, the vibrating body may be formed in a circular cylindrical shape.

[0010]

The vibrator and the support for supporting the vibrator are integrally formed by drawing. The vibrating body is supported at the axial end of the vibrating body by the support portion, so that when the vibrating body is freely vibrating, the vibration mode is a so-called cantilever support type (cantilever type). Therefore, in the case where the length of the vibrating body in the axial direction is the same between the vibrating gyroscope of the present invention and the vibrating gyroscope of the conventional example, the amplitude of the vibrating gyroscope of the present invention is larger than that of the vibrating gyroscope of the conventional both-end supporting type. . Therefore, by increasing the amplitude, the vibration gyro of the present invention has a lower frequency and a higher sensitivity. On the other hand, in the vibrating gyroscope of the present invention and the vibrating gyroscope of the conventional example, when the frequency at the time of free vibration of the vibrating body is the same, the vibrating gyroscope of the present invention has a larger amplitude due to the vibration mode of the cantilever support type. The length of the vibrating body in the axial direction can be made shorter than that of a conventional double-sided vibrating gyroscope, and the vibrating body can be reduced in size.

[0011]

According to the present invention, a vibrating gyroscope which can be easily manufactured, has high sensitivity, and can be downsized can be obtained.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0013]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is an illustrative view taken along line II-II of FIG.

The vibrating gyroscope 10 includes a vibrator 12, and the vibrator 12 includes a vibrator 14. This vibrator 14
Is, for example, made of a constant elastic material and is formed in a bottomed regular triangular cylindrical shape. In this case, the vibrating body 14 has a regular triangular prism-shaped hollow portion 1 extending from one end in the axial direction to the other end by a predetermined length.
6. At one end of the vibrating body 14 in the axial direction, a supporting portion 18 for supporting the vibrating body 14 is provided.
4 and are formed integrally. The vibrating body 14 and the support portion 18 are integrally formed of, for example, a constant elastic material. The support portion 18 includes three support pieces 20a, 20b, 20c and 1
And two support rings 22.

That is, the vibrating body 14 is formed with three rectangular plate-shaped support pieces 20a, 20b and 20c extending outwardly at right angles from three peripheral edges at one end in the axial direction. Further, the periphery of the tip of each of the three support pieces 20, 20 b and 20 c is surrounded by one support ring 22. In this embodiment, the support ring 22 is
For example, it is formed of a disk ring and has three support pieces 20a,
It is formed integrally with 20b and 20c.

The vibrating body 14 and the support 18 formed integrally with the vibrating body 14 are manufactured by, for example, drawing. In this embodiment, for example, the vibrating body 14 and the support portion 18 are integrally formed by drawing a pre-processed material (blank) 24 as shown in FIG. In this case, the pre-processed material 24 includes, for example, a disk-shaped vibrating body forming portion 26. In the circumferential portion of the vibrating body forming portion 26,
Three rectangular plate-shaped support piece forming portions 28a, 28b, and 28c are protrudingly provided at the same intervals.
Further, the three support piece forming portions 28a, 28b and 28
A single support ring forming portion 30, for example, in the form of a ring is formed around c around them. 1
Vibrating body forming portions 26 and three support piece forming portions 28, 28
b and 28c and one support ring forming portion 30 are integrally formed of a constant elastic material or the like. Then, the vibrating body 14 and the supporting portion 18 are integrally manufactured by subjecting the center portion of the vibrating body forming portion 26 of the pre-processed material 24 to drawing.

On the other hand, piezoelectric elements 32a, 32b and 32c are formed on three side surfaces of the vibrating body 12. The piezoelectric element 32a includes a piezoelectric layer 3 made of, for example, ceramics.
4a, electrodes 36a,
38a are formed. Then, one electrode 36a is bonded to one side surface of the vibrating body 14. Similarly, the piezoelectric elements 32b and 32c respectively include the piezoelectric layers 34b and 34c
including. Then, electrodes 36b, on both surfaces of the piezoelectric layer 34b,
38b are formed, and electrodes 36 are formed on both surfaces of the piezoelectric layer 34c.
c, 38c are formed. These piezoelectric elements 32b, 3
One electrode 36b, 36c of 2c is bonded to the other two side surfaces of the vibrating body 14.

The vibrator 12 thus formed is
As shown in FIGS. 4 and 5, for example, it is held by a cylindrical holding member 40 made of a synthetic resin. In this case, one end of the vibrator 12 in the axial direction is
The vibrating gyroscope 10 of this embodiment
Vibration mode is the so-called cantilever type (cantilever support type)
Vibration mode.

In the vibrating gyroscope 10, the piezoelectric element 32
An oscillation circuit (not shown) is connected between a, 32b and 32c. With this oscillation circuit, the vibrating body 14 bends and vibrates in a direction orthogonal to the surface on which the piezoelectric element 32c is formed. In this state, when the vibrating body 14 rotates around its central axis, Coriolis force acts on the vibrating body 14 to change the direction of bending vibration. For this reason, a difference occurs between the output signals of the piezoelectric element 32a and the piezoelectric element 32b. By measuring the difference between these output signals, the rotational angular velocity can be detected.

Since the vibrating gyroscope 10 is in a cantilevered (cantilevered) vibration mode, it is similar to a vibration mode of a both-ends supporting type like the conventional vibrating gyroscope 1 shown in FIGS. The displacement amount becomes larger as compared with.
In this case, if the length of the vibrating body 14 in the axial direction is the same,
The vibration gyro 10 of the present embodiment shown in FIGS. 1, 2, 4 and 5 has a larger amplitude than the conventional vibration gyro 1 shown in FIGS. 7 and 8. Therefore, in the vibration gyro 10 of this embodiment, the frequency is reduced and the sensitivity is increased.

If the resonance frequency of the vibrating body of the conventional vibrating gyroscope 1 and that of the vibrating gyroscope 10 of the present embodiment at the time of free vibration are the same, in other words, if the sensitivity is the same, the vibrating gyroscope 10 of the present embodiment is used. In this case, the length of the vibrating body in the axial direction can be made shorter than in the conventional vibrating gyroscope 1. Therefore, the vibrating gyroscope 1 of this embodiment
At 0, downsizing is possible. In this case, according to the experiment of the inventor, the axial length of the vibrating body can be reduced to １ ／ of the conventional length.

Further, in this vibrating gyroscope 10, FIG.
Unlike the conventional example having a complicated and difficult-to-form vibrating body support structure as shown in FIG. 8, the vibrating body 14 and the supporting portion 18 are integrally formed by drawing or the like, so that the manufacturing is simple. Thus, the manufacturing cost can be reduced. In other words, in the vibrating gyroscope according to the present invention, as in the conventional vibrating gyroscope 1 shown in FIGS. 7 and 8, a manufacturing process of separately preparing a supporting member for supporting the vibrating body and attaching it to the vibrating body is performed. Can be omitted.

FIG. 6 is a perspective view showing another embodiment of the present invention. The vibration gyro 10 of the embodiment shown in FIG.
The formation positions of 2a, 32b and 32c are different. That is, in the vibrating gyroscope shown in FIGS. 1, 2, and 4, etc., three piezoelectric elements 32a, 32b, and 32c are formed on three side surfaces of the vibrating body 14, respectively. However, in the vibrating gyroscope 10 shown in FIG. Three piezoelectric elements 32a, 32
b and 32c are formed on the upper surfaces of the three support pieces 20a, 20b and 20c of the support portion 18 of the vibrating body 14, respectively. The vibrating gyroscope 10 of the embodiment shown in FIG. 6 has the same operation and effect as the above-described embodiment.

In each of the above-described embodiments, the shape of the vibrating body formed by drawing is not limited to a regular triangular cylinder, but may be other polygonal cylinders such as a quadrangular cylinder and a hexagonal cylinder. And may be formed in a cylindrical shape. In this case, the shape of the through-hole is not limited to a regular triangular prism, but may be a polygonal prism such as a quadrangular prism, or a cylindrical shape.

In each of the above embodiments, the vibrating body 14 is formed in a cylindrical shape with a bottom. However, the vibrating body 14 forms a hollow portion 16 with a through hole penetrating from one end to the other end in the axial direction. It may be configured to do so.

In each of the above-described embodiments, the support piece constituting the support portion is formed in a rectangular plate shape. However, the present invention is not limited to the rectangular plate shape, but may be formed in another shape such as a column shape. You may. Further, in each of the above-described embodiments, the support ring constituting the support portion is formed in a disk ring shape. However, the support ring is not limited to the disk ring shape, and may be, for example, a rectangular frame shape. For example, it may be formed in another annular body.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an illustrative view showing one example of a method of manufacturing a vibrating body of the vibrating gyroscope of the embodiment shown in FIGS. 1 and 2;

FIG. 4 is a partially cutaway perspective view showing a method of supporting the vibrating gyroscope shown in FIGS. 1 and 2;

FIG. 5 is a sectional view taken along line VV in FIG. 4;

FIG. 6 is a perspective view showing another embodiment of the present invention.

FIG. 7A is a perspective view showing an example of a conventional vibrating gyroscope, and FIG. 7B is a sectional view thereof.

FIG. 8 is an illustrative view showing a state in which the vibrating gyroscope shown in FIG. 7 is bending vibrating;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Vibration gyroscope 12 Vibrator 14 Vibrating body 16 Hollow part 18 Support part 20a, 20b, 20c Support piece 22 Support ring 24 Pre-processed material (blank) 32a, 32b, 32c Piezoelectric element 34a, 34b, 34c Piezoelectric layer 36a, 36b, 36c, 38a, 38b, 38c Electrode 40 Holding Member

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-61613 (JP, A) JP-A-2-290171 (JP, A) JP-A-56-87823 (JP, A) JP-A-5-1987 240648 (JP, A) Japanese Utility Model 62-119099 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 19/56 G01P 9/04

Claims (4)

(57) [Claims] 1. A bending vibration having a cylindrical hollow portion.
A vibrating body that supports the vibrating body at an axial end of the vibrating body, wherein the vibrating body and the supporting part are integrally formed by performing drawing on a pre-processed material. A vibrating gyroscope, wherein the vibrating body is cantilevered by the support portion. 2. The vibrating gyroscope according to claim 1, wherein said vibrating body is formed in a bottomed cylindrical shape. 3. The vibrating body is formed in a polygonal cylindrical shape.
The vibrating gyroscope according to claim 1 . Wherein said vibrating body is formed into a cylindrical shape, wherein
The vibrating gyroscope according to claim 1 or 2.