JPH052016U - Piezoelectric vibration gyro - Google Patents

Abstract

(57) [Abstract] [Purpose] The drawbacks of the conventional method of supporting a piezoelectric vibrating gyro have been eliminated, and the influence on the bending vibration in the perpendicular direction has been reduced, and the influence has to be made for each vibration direction. To provide a piezoelectric gyro that is symmetrical and has a small influence on the characteristics of the piezoelectric vibration gyro. [Structure] A strip-shaped electrode 21 parallel to the length direction is formed on the outer peripheral surface of the columnar piezoelectric ceramic 20, polarization treatment is performed using the strip-shaped electrode, and a bending vibration mode by the piezoelectric effect of the columnar piezoelectric ceramic is utilized. In a piezoelectric vibrating gyro that is driven and detected, the columnar piezoelectric ceramics 20 are supported and fixed at the nodes of flexural vibration through a belt-shaped ring 30 made of a fiber such as cloth or non-woven fabric or a foam material such as foam styrene or sponge.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piezoelectric vibrating gyro, and more specifically, a piezoelectric vibrating gyro that uses ultrasonic vibration of a piezoelectric vibrator among gyroscopes mounted on ships and automobiles to control its attitude and route. It concerns the improvement of the child support structure.

[0002]

[Prior Art]

 A piezoelectric vibrating gyro is a type of gyroscope that utilizes a mechanical phenomenon in which a Coriolis force is generated in a direction orthogonal to the vibrating direction when a rotating angular velocity is applied to a vibrating object. When the piezoelectric vibration is rotated, a force acts in the direction orthogonal to this vibration due to the action of this Coriolis force, and the other vibration is excited. The magnitude of this vibration is proportional to the magnitude of the vibration on the input side and the rotational angular velocity. Therefore, with the input voltage kept constant, the magnitude of the rotational angular velocity can be obtained from the magnitude of the output voltage.

FIG. 4 shows an example of a schematic structure of a conventional piezoelectric vibrating gyro. Electrodes are formed on both surfaces of adjacent metal prisms 7 having a square cross section, and piezoelectric ceramic thin plates 8 and 9 polarized in the thickness direction are bonded to the adjacent surfaces. This metal prism 7 can flexurally vibrate in two directions orthogonal to each other at substantially the same resonance frequency. When a voltage having a frequency equal to this resonance frequency is applied to the piezoelectric ceramic thin plate 8, the piezoelectric ceramic thin plate 8 is moved. Flexural vibration occurs in the direction in which the joined surface becomes uneven. In this state, no voltage is generated on the piezoelectric ceramic thin plate 9 of the metal prism 7. However, when the metal prism 7 is rotated about the longitudinal direction, the Coriolis force causes the metal prism 7 to join the piezoelectric ceramic 9 surface. Bends and vibrates in the direction of the unevenness, and a voltage proportional to the rotational angular velocity is generated in the piezoelectric ceramics 9.

By the way, from the one end face in the length direction of the metal prism 7 which is the piezoelectric vibrator having the above-mentioned structure and properties, the metal prism 7 is hung from the central portion of the metal face facing the position of approximately 22.4% of the total length. Directly, supporting wires 10 and 10 'each made of a thin metal wire are welded. Further, supporting wires 11 and 11 'each made of a thin metal wire are welded perpendicularly to the central portion of the metal surface facing the position of about 22.4% of the entire length from the other end surface. The positions where these metal wires 10, 10, 11 and 11 'are welded are the nodes of vibration for the bending resonance vibration mode of the prism 7, and the bending vibrations orthogonal to each other should have minimal influence on them. Moreover, a thin metal wire is used for support.

[0005]

[Problems to be solved by the device]

 However, according to the conventional supporting method as shown in FIG. 4, as shown in FIG. 5, the supporting lines 10 and 10 ′ support the contact of vibration almost ideally against bending vibration in the direction of the arrow. It will be. However, at this time, bending strain is generated in the support lines 11 and 11 ', which adversely affects the bending vibration in the direction of the arrow. On the other hand, the supporting lines 10 and 10 'similarly affect the bending vibration in the direction perpendicular to the arrow in the figure. In order to minimize the effect on flexural vibration, the diameter of the support wire should be made as small as possible, but if the support wire is made too thin, there is a risk that the vibration resistance and shock resistance characteristics of the piezoelectric vibrator itself will deteriorate.

Further, in this piezoelectric vibrating gyroscope, the vibrator is composed of a single piezoelectric ceramic, and the strip electrodes formed on the outer peripheral surface thereof are formed by screen printing or vapor deposition. Therefore, it is more dangerous to weld or solder a support wire made of too thin a metal wire in terms of vibration resistance and durability and shock resistance.

The purpose of the present invention was proposed in view of the above problems of the prior art, and eliminates the drawbacks in the conventional method of supporting a piezoelectric vibration gyro, and reduces the influence on bending vibration in the orthogonal direction, Moreover, the purpose of the present invention is to provide a piezoelectric gyro whose influence is symmetrical with respect to each vibration direction and which has little influence on the characteristics of the piezoelectric vibration gyro.

Another object of the present invention is to provide a piezoelectric vibrating gyro that can be stably supported by using a piezoelectric vibrator in which a strip-shaped electrode is formed on the outer circumference of a columnar vibrator made of a single piezoelectric ceramic.

[0009]

[Means for Solving the Problems]

 For this reason, the piezoelectric vibrating gyroscope of the present invention forms a strip electrode parallel to the longitudinal direction on the outer peripheral surface of the columnar piezoelectric ceramic, performs polarization processing using the strip electrode, and produces the piezoelectric effect of the columnar piezoelectric ceramic. In a piezoelectric vibrating gyro that drives and detects using a bending vibration mode, the columnar piezoelectric ceramic is bent and vibrated through a strip ring made of fibers such as cloth or non-woven fabric or foam such as foam styrene or sponge. The basic structure is to support and fix it at the node position of.

[0010]

【Example】

 FIG. 1 is a perspective view showing an example of the structure of a columnar piezoelectric ceramic used in the piezoelectric vibrating gyro of the present invention. Individual strip electrodes 21 are formed. These strip electrodes 21 constitute input / output terminals and are formed directly by curved screen printing or by removing unnecessary portions of electrodes formed over the entire surface by plating or the like by photoetching. It is easy to obtain.

The piezoelectric ceramic cylinder 20 is polarized by using the strip electrodes, and then an AC voltage substantially equal to the resonance frequency of the bending vibration of the piezoelectric ceramic column 20 is applied to a part of the strip electrodes. When the piezoelectric ceramic cylinder 20 is rotated about the length axis with the bending vibration excited, a Coriolis force is generated in the direction orthogonal to the vibration direction, and the rotational angular velocity applied to a part of the strip electrode is generated. A voltage proportional to is generated.

FIG. 2 shows a support tool 30 used in the piezoelectric gyro of the present invention, which is a band-shaped ring made of soft fibers such as gauze and felt, and foam material such as foam polystyrene and sponge.

FIG. 3 is an assembled state of the piezoelectric vibrating gyroscope of the present invention. The supporting tool 30 as shown in FIG. 2 is mounted so as to circulate around two portions of the vibration ceramic node 20 (node line). Has been done. The outer periphery of the support 30 is tightened and reinforced by a hard holder 31 and attached to the outer case 32.

In general, in order to support a resonator that resonates without affecting vibration as much as possible, it is necessary to support a node (or line) of a vibration node with a soft material. However, in order to support it stably against external vibration and shock, it is necessary to fix it so that the vibrator does not shift at the support part. As described above, the support 30 of the present invention is made of soft silicone rubber, and is fixed to the piezoelectric ceramics 20 by a soft silicone adhesive. Therefore, the support 30 does not vibrate even if external vibration or shock is applied. The child can be stably supported so as not to shift.

In addition, in the piezoelectric vibrating gyroscope of the present invention, since the shape of the support 30 is ring-shaped, it is supported symmetrically with respect to both the vibration direction of the excitation vibration and the vibration due to the Coriolis force. The influence of support on the characteristics of the vibration gyro is reduced.

In the above description, the columnar piezoelectric ceramic has a cylindrical shape. However, even if the columnar piezoelectric ceramics have a prism shape with a square axial cross-section or other regular polygonal axial cross-sectional shape. It can be similarly configured.

[0017]

[Effect of the device]

 According to the present invention, the deterioration of the vibration characteristics due to the support is small, the influence on the bending vibration in the two directions orthogonal to each other is small, and the influence is symmetric with respect to each vibration direction. It is possible to obtain a piezoelectric gyro which has little influence on the characteristics of the piezoelectric vibration gyro and which can significantly improve reliability.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a piezoelectric ceramic cylinder used in a piezoelectric vibrating gyro of the present invention.

FIG. 2 is a perspective view showing a support used in the present invention.

FIG. 3 is a perspective view showing the structure of a piezoelectric vibrating gyroscope according to the present invention.

FIG. 4 is a schematic structural view of an example of a conventional piezoelectric vibrating gyro.

FIG. 5 is an explanatory view showing a conventional piezoelectric vibration gyro support method.

[Explanation of symbols]

 1, 1 ', 2, 2'Metallic tuning unit 3, 4, 5, 6 Piezoelectric ceramics thin plate 7 Metal prisms 8, 9 Piezoelectric ceramics thin plate 10, 10', 11, 11 'Metal support wire 20 Piezoelectric ceramic cylinder 21 Strip-shaped electrode 30 Supporting tool 31 Holding tool 32 Outer case

Claims (1)

[Claims for utility model registration] 1. A strip-shaped electrode parallel to the length direction is formed on the outer peripheral surface of the columnar piezoelectric ceramic, and polarization treatment is performed using the strip-shaped electrode to obtain the piezoelectric effect of the columnar piezoelectric ceramic. In a piezoelectric vibrating gyro which is driven and detected by utilizing the flexural vibration mode by, the columnar piezoelectric ceramics are supported and fixed at the node of the flexural vibration through a strip ring made of fiber or foam material. Piezoelectric vibration gyro.