JPS60185111A - Gyroscope device - Google Patents

Abstract

PURPOSE:To reduce costs by a simple structure, to increase detecting sensitivity and to detect an input angular speed up to a high frequency, by a constitution, in which the vibrations of two vibrating arms of a tuning fork, which have a square cross section, are differentially detected by piezoelectric elements for detection at the base parts of the arms. CONSTITUTION:Driving piezoelectric elements 4 and 4' are bonded to the outer surface of the base parts of vibrating arms 1-1' of a tuning fork 1. Piezoelectric elements 40 for detection are bonded to the surfaces, which cross said outer surfaces at right angles. When an angular seed OMEGA is applied around the Z axis, a Coriolis force FC is generated and the vibrating arms 1-1' are bent in the opposite direction. This state is differentially detected by the piezoelectric elements 40. Since two elements 40 are provided, the output sensitivity is made to be zero with respect to the acceleration input in the direction of the X axis, the natural frequency of each vibrating arm having a square cross section is made approximately equal to the vibration frequency of the tuning fork and a deflecting shaft is omitted. Therefore, costs can be reduced, strength can be increased and the tuning fork is directly attached to the base table without using a vibration preventing device. Thus the input angular speed up to a high frequency can be detected.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a gyro device, particularly a vibrating or tuning fork gyro device.

BACKGROUND ART AND PROBLEMS Conventionally, as this type of vibrating gyro device, one shown in FIG. 1, for example, has been proposed.

In the conventional gyro device shown in FIG. 1, a tuning fork (1) is attached to a base (2) via a flexible shaft (3). ) and drive coil (4) are installed, and the output of the displacement detector (6) is input to the drive coil (4) through the drive ring center device (5) to maintain the vibration amplitude of the tuning fork (11) constant. When an angular velocity Ω is input around the axis (Z-Z) of the deflection axis (3) of the tuning fork (11), a Coriolis force Fc corresponding to the vibration velocity V of the tuning fork (11) and the input angular velocity Ω is generated. , thereby causing the entire tuning fork (1) to alternately rotate around the axis (Z-Z).

That is, torsional vibration occurs in the tuning fork (1).

In the conventional example shown in Fig. 1, this torsional vibration of the tuning fork f1) is detected by a torsion detector (8), and this detection output and the output of the drive ring center unit (5) are synchronized by a demoschrake (7). By rectifying the input angular velocity Ω, the input angular velocity Ω is detected and a gyro device is constructed.

However, in such a conventional vibrating gyro device, since the tuning fork (1) with a large output is supported in a cantilevered manner, it is necessary to have a large load capacity of the bending shaft (3), and this part As the Coriolis force Fc corresponding to the input angular velocity Ω is extracted as the rotation angle of the tuning fork [11] which has a large moment of inertia, the sensitivity to the input angular velocity Ω is at its core. ,
Problems include that the entire device becomes large and bulky, that the deflection shaft (3) and torsion detector (8) are composed of separate parts, resulting in a complex structure and low detection sensitivity. There was a point (flaw).

OBJECTS OF THE INVENTION Accordingly, the main object of the present invention is to provide a gyro device that eliminates the above-mentioned drawbacks of the conventional art.

Summary of the Invention In the present invention, two driving piezoelectric elements are attached to the outer surface of a tuning fork near the base of the two (IM) vibrating arms, each having two vibrating arms having a substantially stop square cross section. In addition, the above-mentioned conventional gyro device has an extremely simple structure in which two detection piezoelectric elements are fixed to each of the side surfaces perpendicular to the above-mentioned outer surface, and the above-mentioned tuning fork is directly attached to the base at its base. This solution solves the problems of

EXAMPLE Hereinafter, an example of the gyro device according to the present invention will be described with reference to FIG. 2, which is a perspective view thereof.

In addition, in the same figure, the numerals corresponding to those in FIG. 1 indicate the same elements.

In the embodiment of the invention shown in FIG. 2, a flat base (2)
, the tuning fork ill is placed on the base (2
) directly at its base (1-1) so as to be perpendicular to the plane of the base (1-1). In the present invention, two vibrating arms (
1-B) are formed from rod-shaped members each having a substantially square cross section, and the base (1-1) connects them. Drive piezoelectric elements +41 and (4') are respectively attached to the outer surface near the base (14) of each vibrating arm (l-bi) by a method such as gluing. Two detection piezoelectric elements (40) and (40') are attached to the side surface perpendicular to the above-mentioned outer surface near the base (1-1) of -1') by a method such as adhesive bonding. Drive piezoelectric element f4+, (4'
) is supplied with AC voltage from an AC signal source (5), and the tuning fork +
1+ is vibrated at a constant amplitude. 1) The vibration speed of the fork (1) is denoted by ■'ζ, as shown in FIG.

A tuning fork in such a vibrating state (in 11, the shaft (Z-Z)
When an angular velocity is applied around Ω, it is proportional to the product of the vibrating mass of the tuning fork (1), the vibration velocity ■, and the angular velocity Ω. :I Riolica Fc is in the IIQll(x-X') direction perpendicular to the axis <2-2> and the speed V, and 211#A
The vibration 11ii (14') occurs in the opposite direction, and each time the two vibrations 1itJIf (1-1') are bent in the opposite direction around the axis (Y-Y') in the figure. This bending of each vibrating arm (1-1') causes a difference of 1,
These detection outputs are synchronously rectified together with the AC power from the C1 AC signal source (5) in the digital generator (7), so that the Tj is proportional to the angular velocity. By providing the two detection piezoelectric elements (40) and (4t)') as described above, it is possible to
Output sensitivity can be set to zero.

Fork, tuning fork (the cross section of the vibrating arm (1-1') of 11 is approximately if
E square and square, frequency of tuning fork (1) and vibrating arm (1-1'
) The detection sensitivity can be increased by making the free frequencies around the axis (Y-Y') approximately equal.

Effect of the invention The effects of the present invention are listed below.

That is, (1) The flexible shaft (3) shown in Fig. 1 is no longer necessary, making it possible to reduce the size and cost, as well as reduce shock and vibration.
Excellent strength.

(2) The frequency of the tuning fork and the axis of the vibrating arm (1-1') (X-X
') The so-called tuning condition that equalizes the frequency of vibration in the direction is
This can be achieved by the extremely simple condition of making the W surface of the vibrating arm (1-1') approximately square, reducing manufacturing costs.
The uniformity of performance is 11J.

(3) Two vibrating arms (1-1') are equally vibrating 11 in opposite directions
There is no vibration in the base (1-1) due to only the lunar movement (for this reason, the tuning fork (1) is directly attached to the base (2) without using a vibration isolator such as an elastic body. It can be mounted easily, the structure can be simplified, and even high-frequency human-powered angular velocities can be detected.

[Brief explanation of the drawing]

1 is a perspective view of an example of a conventional gyro device, and FIG. 2 is a perspective view of an embodiment of the present invention. In the figure, (11 is the tuning fork, (1-1) is the base, (1-
1') is a vibrating arm, (2) is a base, t41, (4') is a driving piezoelectric element, (5) is an AC signal source, (7) is a demosulator, (40). (40') indicates a piezoelectric element for detection. Agent Manazuru Ito U-son Figure 1

Claims (1)

[Scope of Claims] 1. A tuning fork consisting of two rod-shaped vibrating arms that alternately vibrate and have an angular cross section and are arranged in parallel, and a base that connects one end of the two vibrating arms; a base to which the base is fixed;
In order to apply a constant vibration of 11 to the tuning fork, two driving piezoelectric elements and an alternating current signal source are installed near the base of the vibrating arm in an outward direction, and two driving piezoelectric elements and an AC signal source are installed near the base of the vibrating arm in the outward direction. A gyro device comprising two detection piezoelectric elements mounted perpendicular to a side surface, the two detection piezoelectric elements being differentially connected. 2. Scope of Claims The gyro device according to item 1 is characterized in that a free deflection frequency of the vibrating arm in a direction orthogonal to the direction of the alternating vibration is approximately the same as the frequency of the tuning fork.