JPH0540818U - Piezoelectric vibration gyro - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a piezoelectric gyro that has less influence on the flexural vibration on the side surface of the piezoelectric vibrating gyro and that can be easily positioned when supporting a node. [Structure] A vibration node at resonance of a flexural vibration mode when a piezoelectric vibrator is housed in the inner peripheral surface at both opening ends of the support tool 110 inward in a radial direction and when the support tool 110 stores the piezoelectric vibrator. The ring-shaped protrusions 108 are provided so as to be located at two positions corresponding to. Therefore, if one opening end is positioned on one node, the other opening end is automatically positioned at the other node. Further, the through holes 109 are provided on the outer peripheral surface of the ring-shaped protruding portion 108 inward in the radial direction and at positions corresponding to the strip electrodes 106 at intervals in the circumferential direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piezoelectric vibrating gyroscope used for posture control of equipment mounted on a moving body such as a ship or an automobile and for a navigation system of an automobile.

[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 perpendicular to the vibration direction when a rotating angular velocity is applied to a vibrating object.

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

Since the magnitude of this new vibration is proportional to the magnitude of the vibration excited in advance and the rotational angular velocity of the vibrator, with the input voltage kept constant, the magnitude of the output voltage changes to the rotational angular velocity. The size of can be calculated.

FIG. 1 is a schematic view of the structure of a conventional piezoelectric vibrating gyro. Piezoelectric ceramic thin plates 102 and 103 polarized in the thickness direction are formed on adjacent surfaces of a metal prism 101 having a square cross section. It is joined. The metal prism 101 can flexurally vibrate in two directions perpendicular to each other at substantially the same resonance frequency. Further, when a voltage having a frequency equal to this 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. In this state, when the metal prism 101 is rotated about the longitudinal direction, the action of the Coriolis force causes the metal prism 101 to perform new bending vibration in the direction in which the surface to which the piezoelectric ceramic thin plate 103 is bonded becomes uneven, and the piezoelectric ceramic A voltage proportional to the rotational angular velocity is generated in the thin plate 103.

In FIG. 1, in order to support this piezoelectric gyro, two metal electrodes that are opposed to each other at a position of about 22.4% of the entire length from one end face of the metal prism 101, that is, a node of vibration for the bending resonance vibration mode. Supporting wire rods 104 and 104 'each made of a metal wire are welded to the metal surface perpendicularly to the surface. Further, at a position where the total length is about 22.4% from the other end face, that is, at the position of a vibration node for the bending resonance vibration mode, the metal wire is orthogonal to the surface on which the metal wire is welded, and the other two metal surfaces are opposed to each other. The support wires 105, 105 'are welded perpendicularly to the surface. Thin metal wires are used for these support wires to minimize the influence on bending vibrations that are orthogonal to each other.

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

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

[0009]

[Problems to be solved by the device]

 In the piezoelectric gyro of FIG. 1, the pair of support wires 104 and 104 'almost ideally support the nodes of vibration for bending vibration in the direction perpendicular to the surface where the piezoelectric ceramic thin plate 102 is joined. The other pair of support wires 105 and 105 'are distorted due to the bending vibration. On the other hand, although the support lines 105 and 105 'ideally support flexural vibrations in the direction perpendicular to the above-mentioned direction, there is a problem that the support lines 104 and 104' have the same adverse effect.

Further, in order to reduce the influence on the flexural vibration, it is necessary to make the diameter of the support wire as thin as possible. However, making the support wire fine makes the vibration resistance and impact resistance characteristics of the vibrator itself. There was a problem of deterioration.

On the other hand, as shown in FIG. 3, when a piezoelectric gyro is to be formed by a piezoelectric vibrator in which the strip electrode 106 is provided on the outer peripheral surface of the above-mentioned known piezoelectric ceramic cylinder 107, the piezoelectric vibrator is supported. A support is needed to do this. As this supporting tool, it is possible to use a supporting wire as shown in FIG.

However, since the strip-shaped electrode 106 formed on the outer peripheral surfaces of the piezoelectric ceramic cylinder and the pipe is formed by screen printing or vapor deposition, a support wire made of a thin metal wire is welded or soldered. However, there is a drawback in that the vibration resistance and impact resistance are deteriorated.

An object of the present invention is to eliminate the above-mentioned defects in the conventional method of supporting a piezoelectric vibrating gyro, reduce the influence on the bending vibration on the side surface of the piezoelectric vibrating gyro, and support the node. The purpose is to provide a piezoelectric gyro that can be easily positioned.

[0014]

[Means for Solving the Problems]

 According to the present invention, a piezoelectric vibrator in which a band-shaped electrode is provided in the longitudinal direction at intervals on the peripheral surface of a piezoelectric ceramic body having a circular cross section, and the piezoelectric vibrator of the piezoelectric vibrator is radially inward along the circumferential direction. The piezoelectric vibrator is housed in the cylinder, and the ring-shaped protrusion is provided on the peripheral surface of the piezoelectric vibrator and at the position of the node. A piezoelectric vibrating gyro, which is characterized in that it is pressed against and supported by the portion, is obtained.

A piezoelectric vibrating gyro is characterized in that the cylinder has a ring-shaped protruding portion and a radial through hole for drawing a lead wire at a position corresponding to the strip electrode. can get.

[0016]

Embodiment An embodiment of the present invention will be described with reference to FIGS.

In FIG. 3, the piezoelectric vibrator is composed of a piezoelectric ceramic cylinder 107 and n strip electrodes 106 formed in parallel on the outer peripheral surface in the longitudinal direction.

The strip electrode 106 can be easily obtained by directly forming 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 ceramic cylinder 107 is polarized using the strip electrode 106 to obtain a piezoelectric vibrator.

This piezoelectric vibrator bends and vibrates by applying an AC voltage between a pair of electrodes of the plurality of strip electrodes 106. When the piezoelectric ceramic cylinder 107 is rotated about the axis of the cylinder in the above-mentioned vibration state, Coriolis force is generated in a direction perpendicular to the vibration direction, and new vibration is vibrated. Occurs.

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

In FIG. 4, the resonance of the bending vibration mode occurs when the piezoelectric vibrator is housed in the inner peripheral surface at both opening ends of the support tool 110 inward in the radial direction and when the piezoelectric vibrator is housed in the support tool 110. The ring-shaped protrusions 108 are provided so as to be located at two positions corresponding to the nodes of the vibrations in. Therefore, if one open end is located on one node, the other open end will automatically be located at the other node. The through-holes 109 are provided at positions corresponding to the band-shaped electrodes 106 from the outer peripheral surface of the ring-shaped protrusion 108 toward the inner side in the radial direction and at intervals in the circumferential direction.

Next, after accommodating the piezoelectric vibrator in the support tool 110, the piezoelectric vibrator is inserted into the through hole 109 with a soft conductive adhesive and supported and fixed at the position of the bending vibration node. The support 110 containing the piezoelectric vibrator is inserted into the outer case 111 and mounted.

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

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

[0026]

[Effect of the device]

 According to the present invention, the vibration resistance and impact resistance of the piezoelectric vibrator itself are less deteriorated, the structure is simple and practical, and the support is made of a relatively soft rubber-like elastic insulating material. Since it is made of a material, it can reduce external influences on vibrations, and it also reduces influences on flexural vibrations on the peripheral surface of the piezoelectric vibration gyro, making it easy to perform positioning when supporting nodes. It is to provide a gyro.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram 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 a structure of a piezoelectric vibrating gyro of 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 Supporting tool 111 Outer case

Claims (2)

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