JPH08178671A - Piezoelectric vibration gyroscope - Google Patents

Abstract

PURPOSE: To downsize a gyroscope and allow the surface mounting by adhering and fixing, to a circuit board, a cylindrical piezoelectric vibrator having a soft elastic body adhered and fixed onto the nodal point or nodal line of vibration. CONSTITUTION: Since a molding 20 of soft elastic body is adhered and fixed onto the nodal point or nodal line of vibration of a cylindrical piezoelectric vibrator 1, and this vibrator 1 provided with the molding 20 is adhered and fixed to a circuit board 18, the board 18 is used also as a piezoelectric vibrator holder to minimize the height and the connecting area. The vibrator 1 is connected to a lead wire connecting terminal 23 on the board 18 by a lead wire 22, the mounting part of a piezoelectric vibration gyroscope driving and detecting circuit and the vibrator 1 are mounted on one surface of the board 18, and a through-hole for a surface mounting terminal 19 is provided on the board end surface to form a power supply and signal taking terminal. For the IC of the mounting part on the board 18, a bare chip part 21 is wire-bonded, and coated with a mold resin 24, whereby the area of the mounting part is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called piezoelectric vibrating gyroscope using ultrasonic vibration of a piezoelectric vibrator, among gyroscopes used for camera shake prevention of a camera-integrated VTR and navigation systems of automobiles.

[0002]

2. Description of the Related Art A piezoelectric vibrating gyroscope, when a rotating angular velocity is applied to a vibrating object (hereinafter, the direction of this exciting vibration is referred to as the X direction), a direction perpendicular to the vibrating (exciting) direction (hereinafter , And the direction of this vibration is referred to as the Y direction.) Is a gyroscope that utilizes a mechanical phenomenon that a Coriolis force is generated in the Y direction. When one of the vibrations is excited and the vibrator is rotated, the Coriolis force causes a force to act in a direction perpendicular to the vibration, and the other vibration is excited.
Since the magnitude of this vibration is proportional to the magnitude of the vibration on the input side and the rotational angular velocity, the magnitude of the rotational angular velocity can be changed from the magnitude of the output voltage proportional to the magnitude of this vibration with the input voltage kept constant. You can ask.

FIG. 2A is a schematic structural view of a piezoelectric vibrator used in a piezoelectric vibrating gyro.

In FIG. 2A, the circumference on the outer peripheral surface of a piezoelectric ceramic cylinder (hereinafter referred to as a piezoelectric vibrator) 1 is 6
Six strip-shaped electrodes 2 parallel to the length direction at equal positions
7 are formed. The six strip electrodes 2 to 7 are alternately arranged along the circumference, and both ends thereof are connected to the connection electrodes 8-1 and 8-2. These strip electrodes 2 to 7 are easily manufactured by directly forming them on a curved surface by screen printing, or by forming them on the entire surface by plating or the like, and then removing unnecessary portions of the electrodes by photoetching.

FIG. 2B is a structural sectional view of the piezoelectric vibrator 1. Of the six strip-shaped electrodes 2 to 7, the earth terminals 2, 4 and 6 are alternately arranged along the circumference, one strip-shaped electrode 3 is a drive terminal, and the remaining two strip-shaped electrodes 5 and 7 are provided. Is the detection terminal.

FIG. 3 is a schematic view of the structure of a conventional piezoelectric gyro. The piezoelectric vibrator 1 is bonded and fixed to the piezoelectric vibrator holder 10 via a silicone rubber 13 having a soft elastic adhesive property. One drive terminal, two detection terminals, and a common ground terminal of the piezoelectric vibrator 1 are respectively connected to the terminals 15 of the piezoelectric vibrator holder 10 by the lead wires 12.
It is connected by soldering. In the piezoelectric vibrator holder 10 including the piezoelectric vibrator 1, the board connection terminal 16 and the circuit board 9 are connected by soldering, and then the metal outer case 1
1 and is molded with the silicone resin 14 from the bottom side. Incidentally, 17 is a terminal pin.

[0007]

In the conventional piezoelectric vibrating gyro, the supporting portion of the piezoelectric vibrator 1 is bonded with a soft elastic silicone rubber at the vibration nodal points or nodal lines of the columnar piezoelectric vibrator vibrating at one wavelength resonance. The silicone rubber is bonded to the piezoelectric vibrator holder, and the piezoelectric vibrator holder is fixed to the circuit board by soldering.

As described above, in the conventional support, there is a problem in that the piezoelectric vibrator 1, the silicone rubber, the holder, and the circuit board are arranged in this order, so that the height direction becomes large.

There is also a problem in that a large connection area is required on the circuit board depending on the size of the piezoelectric vibrator holder.

Therefore, further reduction in size in the height direction and connection area has been desired for the conventional piezoelectric vibration gyro.

An object of the present invention is to provide a piezoelectric vibrating gyro which is smaller than the conventional piezoelectric vibrating gyro and can be surface-mounted.

[0012]

According to the present invention, when a rotational angular velocity is applied, vibration due to Coriolis force is generated in a direction perpendicular to the excitation direction, and it is possible to perform excitation and detection in two directions orthogonal to each other. In a piezoelectric vibrating gyroscope configured by using the piezoelectric vibrator configured as described above, a soft elastic body is bonded and fixed to a vibration node or a nodal line of a columnar piezoelectric vibrator that vibrates at one wavelength resonance, and then the soft elastic body is bonded. A piezoelectric vibrating gyro is obtained in which the columnar piezoelectric vibrator having the above is bonded and fixed to a circuit board.

Further, according to the present invention, a piezoelectric vibration further comprising another electronic circuit component, wherein the columnar piezoelectric vibrator and the other electronic circuit component are mounted only on one surface of the circuit board. You get a gyro.

Further, according to the present invention, a piezoelectric vibrating gyro is characterized in that a half-divided through hole is provided as an electric power source and an output terminal portion on an end face of the circuit board, and the through hole enables surface mounting. Is obtained.

[0015]

When the supporting method of the piezoelectric vibrating gyroscope according to the present invention is used, the supporting portion of the piezoelectric vibrator is composed of the vibrator, the soft elastic body and the circuit board in this order, and the circuit board serves as a holder for the piezoelectric vibrator. By also functioning as above, the conventional height direction and the connection area can be made smaller.

In the piezoelectric vibrating gyroscope of the present invention, the electronic circuit component and the columnar piezoelectric vibrator are mounted only on the upper surface, and half-through holes are formed at the end surface of the circuit board as power source and output terminal portions. By using this portion, surface mounting becomes possible.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A piezoelectric vibrating gyroscope according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a small S as an embodiment of the present invention.
The structural schematic diagram of an MD type piezoelectric vibrating gyro is shown.

In this embodiment, when a rotational angular velocity is given,
Vibration due to Coriolis force is generated in the direction perpendicular to the excitation direction,
In a piezoelectric vibrating gyroscope configured by using a piezoelectric vibrator configured so that it can be excited and detected in two directions orthogonal to each other, on a vibration node or node line of a columnar piezoelectric vibrator that vibrates with one wavelength resonance After the soft elastic body is adhered and fixed, the columnar piezoelectric vibrator provided with the soft elastic body is adhered and fixed to the circuit board.

Further, in this embodiment, the electronic device further includes other electronic circuit components, and the columnar piezoelectric vibrator and the other electronic circuit components are mounted only on one surface of the circuit board.

Further, in the present embodiment, a half-divided through hole is provided on the end surface of the circuit board as a power source and output terminal portion, and the through hole enables surface mounting.

The above structure will be specifically described with reference to FIG. 1. In this embodiment, a soft elastic molded product 20 is bonded and fixed to the vibration node or the nodal line of the columnar piezoelectric vibrator 1. After that, the vibrator provided with the molded article 20 of the soft elastic body is adhered and fixed to the circuit board 18. Thereby, the circuit board 18
Also serves as a holder for the piezoelectric vibrator, and makes the height direction and connection area small. The fixed columnar piezoelectric vibrator 1 is connected to the lead wire connection terminal 23 on the circuit board 18 by the lead wire 22. The circuit board 18 is provided with a piezoelectric vibrating gyro drive / detection circuit mounting component and a columnar piezoelectric vibrator 1 mounted on one surface thereof, and a half-divided through hole serving as a surface mounting terminal 19 is provided on an end surface of the circuit board. This serves as a terminal for power supply and signal extraction. In the IC of the mounted component on the circuit board, the bare chip component 21 is wire-bonded and coated with the resin 24 to reduce the area of the mounted component. After that, the outer metal case 25 is placed on the circuit board 18 and bonded to form a small SMD type piezoelectric vibrating gyro.

[0023]

As described above, according to the present invention, when a rotational angular velocity is applied, a Coriolis force causes vibration in a direction perpendicular to the excitation direction, and excitation and detection in two directions orthogonal to each other are possible. In a piezoelectric vibrating gyroscope configured by using a piezoelectric vibrator configured as described above, a soft elastic body is bonded and fixed to a vibration node or a nodal line of a columnar piezoelectric vibrator that vibrates at one wavelength resonance, and then the soft elasticity Since the columnar piezoelectric vibrator provided with the body is fixed to the circuit board by adhesion, a small and thin piezoelectric vibration gyro can be obtained.

Further, since the columnar piezoelectric vibrator and other electronic circuit parts are provided only on one surface of the circuit board, surface mounting can be performed on the device board of a camera-integrated VTR device or an automobile navigation device.

Further, since half-through holes are provided as the power supply and output terminal portions on the end face of the circuit board, the through holes facilitate the surface mounting on the device board.

[Brief description of drawings]

FIG. 1 is a structural schematic diagram of an SMD type piezoelectric vibrating gyro according to an embodiment of the present invention.

FIG. 2 is a diagram showing a structure of a general piezoelectric vibrator,
(A) is a schematic structural view of the piezoelectric vibrator, and (b) is a structural sectional view of the piezoelectric vibrator.

FIG. 3 is a schematic structural view of a conventional piezoelectric vibrating gyro.

[Explanation of symbols]

1 Piezoelectric vibrator 2,4,6 Band-shaped electrode (ground terminal) 3 Band-shaped electrode (driving terminal) 5,7 Band-shaped electrode (detection terminal) 8-1,8-2 Connection electrode (ground terminal) 9 Piezoelectric vibration gyro drive・ Detection circuit board 10 Piezoelectric vibrator holder 11 Metal outer case 12 Lead wire 13 Silicone rubber 14 Silicone mold resin 15 Lead wire connection holder terminal 16 Circuit board connection holder terminal 17,23 Terminal pin 18 SMD type piezoelectric vibration gyro Drive / detection circuit board 19 Surface mounting terminal 20 Support part molded with soft elastic body 21 Bare chip IC 22 Lead wire 23 Lead wire connection terminal 24 Mold resin 25 Metal outer case

Claims (3)

[Claims] 1. When a rotation angular velocity is applied, a Coriolis force causes vibration in a direction perpendicular to the excitation direction, and a piezoelectric vibrator configured to be capable of excitation and detection in two directions orthogonal to each other is used. In the configured piezoelectric vibrating gyro, a soft elastic body is bonded and fixed to a node or a line of vibration of a columnar piezoelectric vibrator vibrating with one wavelength resonance, and then the columnar piezoelectric vibrator including the soft elastic body is formed into a circuit. A piezoelectric vibrating gyro that is adhesively fixed to a substrate. 2. The piezoelectric vibrating gyro according to claim 1, further comprising another electronic circuit component, wherein the columnar piezoelectric vibrator and the other electronic circuit component are mounted only on one surface of the circuit board. Piezoelectric vibration gyro. 3. The piezoelectric vibrating gyro according to claim 2, wherein a half-divided through hole is provided on the end surface of the circuit board as a power source and an output terminal portion, and the through hole enables surface mounting. Piezoelectric vibrating gyro.