JPH056320U - Piezoelectric vibration gyro - Google Patents

Abstract

(57) [Abstract] [Purpose] Vibrations that eliminate the drawbacks of conventional piezoelectric vibration gyro support methods, facilitate the alignment of the support positions, and support without welding or soldering, and facilitate the assembly process. To provide a vibrator for a gyro. A piezoelectric vibrating gyroscope in which a strip-shaped electrode 2 parallel to the longitudinal direction is formed on an outer peripheral surface of a piezoelectric vibrator 1 and is driven and detected by utilizing a bending vibration mode due to a piezoelectric lateral effect of the piezoelectric vibrator. A needle-shaped hole 3 is provided from both end surfaces 4 of the piezoelectric vibrator 1 inward in the axial direction to a position corresponding to a bending vibration node, and a support 5 is inserted into the hole 3. Support.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piezoelectric vibrating gyro, and more specifically, it relates to a gyroscope used for a posture control of a moving body such as a ship or an automobile and equipment mounted on the moving body itself, a navigation system of an automobile, and the like. The present invention relates to the shape and support method of a vibrator in a piezoelectric vibrating gyro that utilizes ultrasonic vibration.

[0002]

[Prior Art]

 A piezoelectric vibrating gyro is a gyroscope that utilizes the mechanical phenomenon that 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 oscillator is rotated with one vibration excited, a force acts in the direction orthogonal to this vibration due to the action of the Coriolis force described above, 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 determined from the magnitude of the output voltage.

FIG. 4 shows an example of a schematic structure of a conventional piezoelectric vibrating gyro. Piezoelectric ceramics thin plates 8 and 9 polarized in the thickness direction are joined to adjacent surfaces of a metal prism 7 having a square cross section. This metal prism 7 can flexurally vibrate in two directions orthogonal to each other at substantially the same resonance frequency, and 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 will be moved. Flexural vibration occurs in the direction in which the joined surface becomes uneven. When the metal prism 7 is rotated about its length in this state, the Coriolis force causes the metal prism 7 to bend and vibrate in the direction in which the surface to which the piezoelectric ceramics 9 is bonded becomes uneven, and the metal prism 7 rotates to the piezoelectric ceramic 9. A voltage proportional to the angular velocity is generated.

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, a supporting wire 11 made of a thin metal wire perpendicular to the surface where the metal wire is welded at a position of approximately 22.4% of the entire length from the other end surface, and is perpendicular to the metal surface at the center of the opposing metal surface 11, 11 'is welded. The portions where these metal wires 10, 10, 11 and 11 'are welded serve as nodes of vibration for the bending resonance vibration mode of the prism 7, and the bending vibrations that are orthogonal to each other should have a minimal effect on each. It is supported by a thin metal wire. Furthermore, electrode lead wires are soldered to the electrodes of the piezoelectric ceramic thin plate and connected to the drive and detection circuits.

[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. At this time, bending strains are 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 support lines 10 and 10 'similarly affect the bending vibration in the direction orthogonal to the arrow in the figure. The diameter of the support wire should be made as small as possible in order to minimize the effect on flexural vibration, but if the support wire is made too thin, there is a risk of degrading the vibration resistance characteristics and shock resistance characteristics of the piezoelectric vibrator itself. ..

According to such a conventional supporting method, it is difficult to accurately align the positions of the supporting wires and weld them, and if the supporting position deviates from the node of the bending vibration, the bending vibration is greatly affected. It aggravates the detection system.

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 supporting wire made of too thin a metal wire in view of vibration resistance and durability and shock resistance.

The object of the present invention was proposed in view of the above problems of the prior art. It eliminates the drawbacks of the conventional method of supporting a piezoelectric vibration gyro, facilitates the alignment of the supporting position, and prevents welding. Another object is to provide a vibrator for a vibration gyro that can be supported without soldering and can be easily assembled.

[0009]

[Means for Solving the Problems]

 For this reason, the piezoelectric vibrating gyroscope of the present invention forms a band-shaped electrode on the outer peripheral surface of a vibrator (hereinafter referred to as “vibrator”) composed of a piezoelectric ceramic cylinder or pipe, and flexural vibration due to the piezoelectric lateral effect of the vibrator. In a piezoelectric vibration gyro that is driven and detected by using a mode, a needle-like hole is formed up to the position of the bending vibration node of the vibrator, and the vibrator is provided at its supporting position. It is characterized in that a support made of a conductive material such as a metal wire is pressure-bonded, adhered or welded to the needle-shaped hole to support the vibrator.

[0010]

【Example】

 FIG. 1 is a perspective view showing a structural example of a piezoelectric vibrator and a supporting portion used in a piezoelectric vibrating gyro configured using the piezoelectric vibrating gyro support of the present invention, and FIGS. FIG. 3 is a cross-sectional view showing a structure and an assembling method of a piezoelectric vibrator for a piezoelectric vibrating gyroscope and a support according to the present invention. On the outer peripheral surface of the piezoelectric vibrator 1, n strip electrodes 2 (here, n = 6 will be described) are formed in parallel with the length direction. The strip electrode 2 can be easily obtained by directly forming it by curved surface screen printing or by removing unnecessary portions of the electrode formed on the entire surface by plating or the like by photoetching.

A needle-shaped hole 3 is formed from one end face in the length direction to the inside from a circular face 4 which is both end faces of the piezoelectric vibrator, to a position of about 22.4% of the entire length. The tip end of the piezoelectric vibrator 5 is inserted into the hole 3 and pressure-bonded or adhered to the piezoelectric vibrator 1 to be supported by the support base 6.

The piezoelectric vibrator shown in FIG. 1 is polarized by using the strip electrodes, and then a part of the strip electrodes is subjected to an AC voltage substantially equal to the resonance frequency of the bending vibration of the piezoelectric ceramic cylinder 20. When the piezoelectric ceramic cylinder 20 is rotated about the length axis in a state in which bending vibration is generated by applying a voltage, a Coriolis force is generated in a direction orthogonal to the vibration direction, which is different from the driving strip electrode. A voltage proportional to the angular velocity of rotation applied to the strip electrode is generated.

FIG. 2A is a cross section taken along the axis of the cylinder of the piezoelectric vibrator, and the support hole 3 has a needle shape from one end face in the length direction to a position of about 22.4% of the entire length. Has been formed. The size of the needle-shaped hole 3 is set so that the support 5 does not hinder the movement of the vibrator. FIG. 2B is a cross-sectional view showing the structure of the piezoelectric vibrating gyro support 5, which is made of a conductive spring material such as phosphor bronze. Then, the tip thereof is sharp so as not to interfere with the bending vibration of the piezoelectric vibrator 1. The support 5 is configured to have a degree of freedom in the arrow direction due to its spring property. Then, the piezoelectric vibrator 1 is inserted into the support 5 as shown in FIG. The tip of the support tool 5 is inserted into the needle-shaped hole 3 of the vibrator. The support tool 5-1 and the support tool 5-2 are spread by the piezoelectric vibrator 1 in the direction of the arrow, and the tip of the support tool 5 is crimped to the piezoelectric vibrator 1 due to the spring property of the support tool 5. 1 is supported.

At the time of assembly, the supporting position of the piezoelectric vibrator 1 is easily positioned by the hole 3 of the vibrator 1, so that the piezoelectric vibrator 1 is supported without displacement. In addition, since the tip of the support 5 is pressed into the hole 3 of the piezoelectric vibrator 1 to support the piezoelectric vibrator 1, steps such as welding and soldering are unnecessary.

In the above description, the piezoelectric vibrating gyroscope composed of the piezoelectric ceramic cylinder is described for the sake of convenience, but it goes without saying that the piezoelectric vibrating gyroscope may have the same structure even if it has a prismatic shape.

[0016]

[Effect of the device]

 According to the present invention, the positioning of the support position of the piezoelectric vibrator 1 becomes easy, and the vibrator is supported by crimping the support tool only by inserting the vibrator into the support tool. For this reason, steps such as welding and soldering of the supporting tool are unnecessary, and the manufacturing cost can be reduced. Further, according to the present invention, the presence of the needle-shaped hole 3 prevents the supporting position from being displaced during assembly, and it is possible to obtain the support with less influence on the characteristics of the piezoelectric vibrating gyro, thereby providing a highly accurate piezoelectric vibrating gyro. It has a great industrial value.

[Brief description of drawings]

FIG. 1A is a perspective view showing the structure of a piezoelectric vibrating gyroscope according to a position embodiment of the present invention. FIG. 3B is a perspective view showing a needle-shaped hole of a piezoelectric vibrator for a piezoelectric vibration gyroscope according to an embodiment of the present invention.

FIG. 2A is an axial cross-sectional view showing a structure of a support portion of a vibrator for a piezoelectric vibration gyroscope according to an embodiment of the present invention. FIG. 1B is a sectional view showing the structure of a support for a piezoelectric vibrating gyroscope according to an embodiment of the present invention.

FIG. 3 is a perspective view showing an example of a structure of a piezoelectric vibrating gyro configured using the piezoelectric vibrating gyro support of the present invention and a piezoelectric vibrator.

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]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric ceramics column 2 Strip electrode 3 Needle-shaped hole 4 Circular surface (end face) 5 Supporting tool 6 Supporting base 6 External electrode 7 Metal prism 8 and 9 Piezoelectric ceramic thin plate 10, 10 ', 11, 11' Metal supporting wire

Claims (1)

[Claims for utility model registration] 1. A band-shaped electrode parallel to the length direction is formed on the outer peripheral surface of the piezoelectric vibrator, and the piezoelectric vibrator is driven by utilizing the bending vibration mode by the piezoelectric lateral effect. In the piezoelectric vibrating gyro for performing detection, needle-shaped holes are provided from both end faces of the piezoelectric vibrator inward in the axial direction to positions corresponding to flexural vibration nodes, and a supporting tool is provided in the holes. A piezoelectric vibration gyro characterized by being inserted.