JP2545963Y2 - Piezoelectric vibration 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 piezoelectric vibratory gyroscope used for attitude control of equipment mounted on a moving body such as a ship or a car, and a navigation system for a car.

[0002]

2. Description of the Related Art A piezoelectric vibrating gyroscope is a type of gyroscope utilizing a mechanical phenomenon in which when a rotating object is given a rotational angular velocity, a Coriolis force is generated in a direction perpendicular to the vibration direction.

When the piezoelectric vibrator is rotated in a state where one-way vibration is excited by applying a voltage, a force acts on the piezoelectric vibrator in a direction perpendicular to the vibration by the action of the Coriolis force described above. A new vibration is excited, and an output voltage can be obtained based on the new vibration.

Since the magnitude of this new vibration is proportional to the magnitude of the previously excited vibration and the rotational angular velocity of the vibrator,
With the input voltage kept constant, the magnitude of the rotational angular velocity can be obtained from the magnitude of the output voltage.

FIG. 1 is a schematic structural view of a conventional piezoelectric vibrating gyroscope. Piezoelectric ceramic thin plates 102 and 103 polarized in a thickness direction are joined to adjacent surfaces of a metal prism 101 having a square cross section. I have. The metal prism 101 is capable of bending vibration in two directions perpendicular to each other at substantially the same resonance frequency. When a voltage having a frequency equal to the resonance frequency is applied to the piezoelectric ceramic thin plate 102, the metal prism 101 bends and vibrates in a direction in which the surface to which the piezoelectric ceramic thin plate 102 is bonded becomes uneven, as shown in FIG. When the metal prism 101 is rotated about the longitudinal direction in this state, the metal prism 101 performs a new bending vibration in a direction in which the surface to which the piezoelectric ceramic thin plate 103 is bonded becomes uneven due to the action of the Coriolis force. 1
At 03, a voltage proportional to the rotational angular velocity is generated.

In FIG. 1, for supporting the piezoelectric gyro, two metal members opposing each other at a position approximately 22.4% of the entire length from one end face of the metal prism 101, that is, a position of a vibration node with respect to the bending resonance vibration mode. Support wires 104 and 104 'each made of a metal wire are welded to the surface perpendicular to the surface. Furthermore, the total length is 2 from the other end face.
At the position of 2.4%, that is, at the position of the node of the vibration with respect to the bending resonance vibration mode, the supporting wires 105, 105 made of metal wires are respectively provided on the other two metal surfaces opposed to each other at right angles to the surface where the metal wires are welded. 'Is welded perpendicular to that plane. Thin metal wires are used for these support wires so as to minimize the influence on each of the bending vibrations orthogonal to each other.

[0007] As a piezoelectric vibrator, a piezoelectric vibrator in which strip-shaped electrodes are provided in the longitudinal direction at intervals on the peripheral surface of a piezoelectric ceramic cylinder is also known.

A piezoelectric vibrator using a piezoelectric ceramic pipe instead of the piezoelectric ceramic cylinder is also known.

[0009]

In the piezoelectric gyro shown in FIG. 1, a pair of supporting wires 104 and 104 'almost ideally oscillate with respect to bending vibration in a direction perpendicular to the surface to which the piezoelectric ceramic thin plate 102 is joined. Support the nodes of
The other pair of support wires 105, 105 'is distorted by the bending vibration. On the other hand, for the bending vibration in the direction perpendicular to the above-mentioned direction, the support lines 105 and 105 'provide ideal support, but there is a problem that the support lines 104 and 104' similarly have an adverse effect.

In order to reduce the influence on the bending vibration, it is necessary to make the diameter of the support wire as small as possible.
Making the support wires finer has the problem of deteriorating the vibration resistance and shock resistance of the vibrator itself.

On the other hand, as shown in FIG. 3, a band-shaped electrode 10
When a piezoelectric gyro is to be constituted by the piezoelectric vibrator subjected to step 6, a support for supporting the piezoelectric vibrator is required. It is conceivable to use a support wire as shown in FIG. 1 as this support tool.

However, since the band-shaped electrodes 106 formed on the outer peripheral surfaces of the piezoelectric ceramic cylinder and the pipe are formed by screen printing or vapor deposition, etc.
When a supporting wire made of a thin metal wire is supported by welding or soldering, there is a disadvantage that vibration resistance and impact resistance are deteriorated.

An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional method of supporting a piezoelectric vibrating gyroscope, to reduce the influence on bending vibration on the side surface of the piezoelectric vibrating gyroscope, and to determine the position when supporting a node. Another object of the present invention is to provide a piezoelectric gyro that can be easily performed.

[0014]

According to the present invention, there is provided a piezoelectric vibrator in which band electrodes are provided in the longitudinal direction at intervals on the peripheral surface of a piezoelectric ceramic body having a circular cross section, A cylinder having a ring-shaped protrusion for supporting a node of the piezoelectric vibrator on a radially inner side, wherein the piezoelectric vibrator is housed in the cylinder, and on a peripheral surface of the piezoelectric vibrator and A piezoelectric vibrating gyroscope is characterized in that the piezoelectric vibrating gyroscope is supported by being pressed against the ring-shaped protrusion at the position of the node.

Also, a piezoelectric vibrating gyroscope characterized in that the cylinder has a radial through hole for leading a lead wire at a position corresponding to the band-shaped electrode at a ring-shaped protruding portion thereof. Can be

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

In FIG. 3, the piezoelectric vibrator comprises a piezoelectric ceramic column 107 and n strip electrodes 106 formed on its outer peripheral surface in parallel with the longitudinal direction.

The strip-shaped electrode 106 can be easily obtained by directly forming the screen by curved screen printing or by removing unnecessary portions of the electrode formed on the entire surface by plating or the like by photoetching.

The piezoelectric vibrator is obtained by polarizing the piezoelectric ceramic column 107 using the strip-shaped electrode 106.

This piezoelectric vibrator is connected to the plurality of strip electrodes 10.
By applying an AC voltage between a pair of electrodes among the six electrodes, bending vibration occurs. When the piezoelectric ceramic cylinder 107 is rotated about the axis of the cylinder in the vibration state, a Coriolis force is generated in a direction perpendicular to the vibration direction, and a new vibration is vibrated. Occur.

The direction of vibration is determined by the electrode to which a voltage is applied.

In FIG. 4, when the piezoelectric vibrator is accommodated in the support 110 in a radially inward direction on the inner peripheral surface at both open end portions of the support 110, and when the piezoelectric vibrator is housed in the support 110, resonance of the bending vibration mode occurs. Ring-shaped protrusions 108 are provided at two positions corresponding to the nodes of the vibration in. Therefore, if one open end is positioned on one node, the other open end is automatically positioned on the other node. Further, the through holes 109 are provided at positions corresponding to the band-shaped electrodes 106 from the outer peripheral surface of the ring-shaped projecting portion 108 toward the radial inside and at intervals in the circumferential direction.

Next, after the piezoelectric vibrator is housed in the supporting member 110, the piezoelectric vibrator is supported and fixed at the position of the node of the bending vibration by inserting a soft conductive adhesive into the through hole 109,
Next, the support 1 in which the piezoelectric vibrator is housed in the outer case 111
Insert 10 and attach.

The support 110 is made of a conductive elastic material such as silicon rubber.

It should be noted that even if the piezoelectric ceramic body has a cylindrical shape, a square cross-sectional shape, or any other regular polygonal cross-sectional shape, the same operation as described above is performed.

[0026]

According to the present invention, the deterioration of the vibration resistance and shock resistance of the piezoelectric vibrator itself is reduced, the structure is simple and practical, and the support is relatively soft rubber-like. Since it is made of an elastic insulating material, the external influence on vibration can be reduced, and the influence on bending vibration on the peripheral surface of the piezoelectric vibrating gyroscope is reduced, and positioning when supporting nodes is easy. It is to provide a piezoelectric gyro that can be performed in

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a conventional piezoelectric vibrating gyroscope.

FIG. 2 is an explanatory view of a conventional piezoelectric vibration gyro support method.

FIG. 3 is a perspective view showing the structure of the piezoelectric vibrator of the present invention.

FIG. 4 is a perspective view showing the structure of the piezoelectric vibrating gyroscope according to the present invention.

[Explanation of symbols]

 101 Metal prism 102,103 Piezoelectric ceramic thin plate. 104, 104 ', 105, 105' Metal support wire 106 Band electrode 107 Piezoelectric ceramic cylinder 108 Ring-shaped protrusion 109 Through hole 110 Support 111 Outer case

Claims (2)

(57) [Scope of request for utility model registration] 1. A piezoelectric vibrator in which band electrodes are provided in the longitudinal direction at intervals on a peripheral surface of a piezoelectric ceramic body having a circular cross section, and nodes of the piezoelectric vibrator radially inward along the circumferential direction. And a cylinder having a ring-shaped protrusion for supporting the piezoelectric vibrator. The piezoelectric vibrator is housed in the cylinder, and the ring-shaped protrusion is provided on a peripheral surface of the piezoelectric vibrator and at a position of the node. A piezoelectric vibrating gyroscope characterized by being supported by pressure contact with the piezoelectric vibrating gyroscope. 2. The piezoelectric vibrating gyroscope according to claim 1,
A piezoelectric vibrating gyroscope, wherein the cylinder has a radial through hole for leading a lead wire at a position corresponding to the strip-shaped electrode at a ring-shaped protruding portion thereof.