JP2002221417A - Vibration gyro - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration gyro having a stable property for the gyro. SOLUTION: The vibration gyro 10 includes a vibrator 12 that is made chiefly of piezoelectric ceramics and formed like a regular rectangular prism. The vibrator 12 is supported by a support member 22 made of 42Ni, for example. The support member 22 is connected to a support base 32 formed on a mount base 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope, and more particularly to a vibrating gyroscope used, for example, for detecting rotation of a car navigation system or rollover of a car.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view showing an example of a conventional vibrating gyroscope. A vibrating gyroscope 1 shown in FIG. 7 includes a columnar vibrator 2 mainly composed of piezoelectric ceramics. The vibrator 2 is mounted on a support base 5 of a mounting base 4 via a support member 3 made of phosphor bronze. The vibrating gyroscope 1 shown in FIG. 7 vibrates in the x-axis direction when the Coriolis force does not act, but when the Coriolis force acts by rotating around the z-axis, a vibration mode in the y-axis direction is also added, and this y The angular velocity is detected by detecting the vibration in the axial direction. That is, in the vibrating gyroscope 1, the vibration modes in the two directions of the x-axis direction and the y-axis direction must be stable without being affected by the environment. Therefore, special attention is required for the support structure of the vibrator 2.

[0003]

In the vibrating gyroscope 1 shown in FIG. 7, since the supporting member 3 is required to have elasticity and electrical conductivity, the supporting member 3 is made of phosphor bronze, while the vibrator 2 is mainly composed of phosphor bronze. Since it is made of a non-metallic material such as piezoelectric ceramics, the difference in thermal expansion between the vibrator 2 and the support member 3 is large. If the difference between the thermal expansions of the vibrator 2 and the support member 3 is large, the temperature change of the vibration mode in the x-axis direction and the y-axis direction is also large. As a result, stable gyro characteristics cannot be obtained. If the difference in thermal expansion between the vibrator 2 and the support member 3 is large, the thermal stress applied to the connection between the vibrator 2 and the support member 3 is large, and the durability of the vibrating gyroscope 1 against thermal shock and the like is poor. .

[0004] Therefore, a main object of the present invention is to provide a vibration gyro capable of obtaining stable gyro characteristics.

[0005]

A vibrating gyroscope according to the present invention comprises: a columnar vibrator mainly composed of a non-metal; a support member electrically and mechanically connected to the vibrator to support the vibrator; In a vibrating gyroscope having a mounting base connected to a support member, a metal material having a coefficient of thermal expansion in the range of 0.1 to 10 times the thermal expansion coefficient of the vibrator is used as a material of the support member. A vibration gyro characterized by the following. In the vibrating gyroscope according to the present invention, for example, an alloy mainly containing Fe and Ni is used as a material of the support member.

In the vibrating gyroscope according to the present invention, a metal material having a thermal expansion coefficient in the range of 0.1 to 10 times the thermal expansion coefficient of the vibrator is used as the material of the supporting member. The difference in thermal expansion with the member is reduced.

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

[0008]

FIG. 1 is a schematic plan view showing an example of a vibrating gyroscope according to the present invention, and FIG. 2 is a perspective view showing a vibrator used in the vibrating gyroscope. The vibrating gyroscope 10 shown in FIG. 1 includes a vibrator 12 having, for example, a regular quadrangular prism shape.

As shown in FIG. 2, the vibrator 12 includes, for example, a strip-shaped first piezoelectric substrate 14a and a second piezoelectric substrate 14b made of piezoelectric ceramics. The first piezoelectric substrate 14a and the second piezoelectric substrate 14b are stacked and bonded. Further, the first piezoelectric substrate 14a and the second piezoelectric substrate 14b are polarized in opposite thickness directions. The polarization directions of the first piezoelectric substrate 14a and the second piezoelectric substrate 14b may be opposite to each other.

On the main surface of the first piezoelectric substrate 14a, two divided electrodes 16, 16 are formed at intervals in the width direction. A common electrode 18 is formed on the main surface of the second piezoelectric substrate 14b. Further, the first piezoelectric substrate 1
4a and the second piezoelectric substrate 14b, the intermediate electrode 2
0 is formed.

In the vibrator 12, the first piezoelectric substrate 1
Since the piezoelectric substrate 4a and the second piezoelectric substrate 14b are polarized in opposite thickness directions, if a drive signal such as a sine wave signal is applied between the two divided electrodes 16, 16 and the common electrode 18, the first piezoelectric substrate 14b becomes first. The piezoelectric substrate 14a and the second piezoelectric substrate 14b vibrate in opposite directions. In this case, when the first piezoelectric substrate 14a extends in a direction parallel to the main surface, the second piezoelectric substrate 14b contracts in a direction parallel to the main surface. Conversely, when the first piezoelectric substrate 14a is contracted in a direction parallel to its main surface, the second piezoelectric substrate 14b extends in a direction parallel to its main surface.
Therefore, the first piezoelectric substrate 14a and the second piezoelectric substrate 14b bend and vibrate in a direction perpendicular to the main surface, with a portion slightly inside from both ends in the longitudinal direction as a node portion.

At four positions corresponding to nodes on the upper and lower surfaces of the vibrator 12, four support members 22 are provided.
Is attached by, for example, soldering or a conductive adhesive, and the vibrator 12 is sandwiched from above and below. The support member 22 provides a drive signal to the divided electrode and the common electrode of the vibrator 12 and also serves as a conductive line for obtaining a detection signal from the divided electrode and the common electrode. Therefore, one support member 2 in the longitudinal direction of the upper surface of the vibrator 12
The central portion 22a of the second support member 22 is electrically connected to one divided electrode 16, and the central portion 22a of the other support member 22 in the longitudinal direction is electrically connected to the other divided electrode 16. The central portions 22a of the two support members 22 on the lower surface of the vibrator 12 are
It is electrically connected to the common electrode 18.

The above-mentioned supporting member 22 has a central portion 22a formed as a substantially rectangular plate-like pad, and a substantially Z-shaped pad on both sides of the central portion 22a for obtaining the effect of confining the vibration of the vibrator 12. A rectangular plate-like end portion 22c is formed via the intermediate portion 22b. These support members 22 are formed by punching, for example, a 42Ni plate material.

The vibrating gyroscope 10 further includes a box-shaped mounting base 30 made of, for example, a synthetic resin. On the inner walls on both sides in the width direction of the mounting base 30, for example, four rectangular parallelepiped support bases 32 are formed integrally with the mounting base 30 at intervals.

The four ends 22c of the two support members 22 attached to the lower surface of the vibrator 12 are attached to the lower surfaces of the four support bases 32 of the attachment base 30, for example, with an adhesive. Similarly, the four ends 22 c of the two support members 22 attached to the upper surface of the vibrator 12 are attached to the upper surfaces of the four support stands 32 of the attachment base 30 by, for example, an adhesive.

In the vibrating gyroscope 10 shown in FIG. 1, the vibrator 12 is mainly made of piezoelectric ceramics, the coefficient of thermal expansion of which is, for example, 1.1 × 10 ⁻⁶ / ° C., and the supporting member 22 is made of 42Ni. Since the thus formed 42Ni has a thermal expansion coefficient of, for example, 4.5 × 10 ⁻⁶ / ° C.,
In particular, the difference in thermal expansion between the vibrator 12 and the support member 22 is smaller than that of a piezoelectric gyro having a support member made of phosphor bronze having a thermal expansion coefficient of, for example, 17 × 10 ⁻⁶ / ° C.

In the vibrating gyroscope 10, since the difference in thermal expansion between the vibrator 12 and the support member 22 is reduced, the support of the vibrator 12 is stabilized without being affected by temperature, and the temperature of the output of the vibrating gyroscope 10 is reduced. Stable gyro characteristics such as drift characteristics and temperature characteristics of sensitivity can be obtained.

In the vibrating gyroscope 10, the difference in thermal expansion between the vibrator 12 and the support member 22 is reduced.
The thermal stress applied to the connection between the vibrator 12 and the support member 22 is also reduced, and the durability of the vibrating gyroscope 10 against thermal shock and the like is improved.

FIG. 3 is a graph showing a change in sensitivity to thermal shock of the vibrating gyroscope 10 shown in FIG. 1, and FIG. 4 is a graph showing a change in sensitivity to thermal shock of a vibrating gyroscope having a supporting member made of phosphor bronze. From the graphs shown in FIGS. 3 and 4, the change in sensitivity after the thermal shock test was performed 1000 times was 20% or more for the vibrating gyroscope in which the supporting member was formed of phosphor bronze, whereas the change in sensitivity was 42Ni. It can be seen that the vibration gyro 10 shown in FIG.

FIG. 5 is a graph showing the output change with respect to the thermal shock of the vibrating gyroscope 10 shown in FIG. 1, and FIG. 6 is a graph showing the output change with respect to the thermal shock of the vibrating gyroscope having the supporting member made of phosphor bronze. According to the graphs shown in FIGS. 5 and 6, the output change after the thermal shock test was performed 1000 times also showed that the vibration gyro having the supporting member made of phosphor bronze had a variation of 100 degrees / second or more. , 42
The vibrating gyroscope 10 shown in FIG.
It can be seen that the variation is improved to within 30 degrees / sec and the variation itself is also small.

In the above-described vibrating gyroscope 10, the supporting member 22 is made of 42Ni. In the present invention, however, 36Ni having a thermal expansion coefficient of, for example, 1.2 × 10 ⁻⁶ / ° C.
The support member 22 may be constituted by. In this case, since the difference in thermal expansion between the vibrator 12 and the support member 22 is further reduced, an effect superior to the above-described effect is achieved.

In the vibrating gyroscope 10 described above, a box-shaped mounting base 30 having a regular quadrangular prism-shaped vibrator 12, a support member 22 having a substantially Z-shaped intermediate portion 22b, and a rectangular parallelepiped support 32 is provided. Although used, they may be formed in other shapes in the present invention.

[0023]

According to the present invention, a vibrating gyroscope having stable gyro characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is an illustrative plan view showing one example of a vibrating gyroscope according to the present invention.

FIG. 2 is a perspective view showing a vibrator used in the vibrating gyroscope shown in FIG.

FIG. 3 is a graph showing a change in sensitivity to thermal shock of the vibrating gyroscope shown in FIG.

FIG. 4 is a graph showing a change in sensitivity to a thermal shock of a vibrating gyroscope having a supporting member made of phosphor bronze.

FIG. 5 is a graph showing an output change with respect to a thermal shock of the vibrating gyroscope shown in FIG. 1;

FIG. 6 is a graph showing an output change with respect to a thermal shock of a vibrating gyroscope having a supporting member made of phosphor bronze.

FIG. 7 is a perspective view showing an example of a conventional vibrating gyroscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration gyroscope 12 Vibrator 14a 1st piezoelectric substrate 14b 2nd piezoelectric substrate 16 Split electrode 18 Common electrode 20 Intermediate electrode 22 Supporting member 22a Central part 22b Intermediate part 22c End part 30 Mounting base 32 Support base

Claims (2)

[Claims] 1. A columnar vibrator mainly composed of a non-metal, a support member electrically and mechanically connected to the vibrator to support the vibrator, and a mounting base connected to the support member. A vibrating gyroscope comprising: a metal material having a coefficient of thermal expansion in a range of 0.1 to 10 times a coefficient of thermal expansion of the vibrator as a material of the supporting member. 2. The material of said support member is Fe and N.
The vibrating gyroscope according to claim 1, wherein an alloy containing i as a main component is used.