JPH0319488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention was filed on June 17, 1982 by the same applicant.
Japanese Patent Application No. 104331/1982 filed on 1983 relates to an improvement of a gyro device, and in particular relates to a gyro device having a new driving device with a simple structure and high performance.

Conventionally, this type of vibrating gyroscope device is
For example, one shown in FIG. 1 is provided. In the conventional gyro device shown in Fig. 1,
A tuning fork 1 is attached to a base 2 via a flexible shaft 3.
A displacement detector 6 and a drive coil 4 are installed near the upper end of the tuning fork 1, and the output of the displacement detector 6 is inputted to the drive coil 4 through a drive amplifier 5 to keep the vibration amplitude of the tuning fork 1 constant. keeping. When the angular velocity Ω is input around the axis (Z-Z) of the deflection axis 3 of the tuning fork 1, the vibration velocity v of the tuning fork 1 and the input angular velocity Ω
A Coriolis force Fc corresponding to is generated, which causes 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 1 is detected by a torsion detector 8 provided in the tuning fork 1, and this detection output and the output of the drive amplifier 5 are synchronously rectified by a demodulator 7. In this way, the input angular velocity Ω is detected.

However, in such a conventional vibrating gyro device, since the Coriolis force Fc corresponding to the input angular velocity Ω is extracted as the rotation angle of the tuning fork 1 having a large moment of inertia, the sensitivity to the input angular velocity Ω is poor. If you try to increase this, the entire device will become larger, and the unbalance of the tuning fork 1 will directly affect the detection accuracy, so the requirements for processing accuracy will be severe.
If the driving frequency of the tuning fork 1 is lowered in an attempt to avoid this, the disturbance due to the imbalance of the tuning fork 1 will increase, the frequency characteristics will deteriorate, and since the tuning fork 1 is supported in a cantilevered manner, the load on the bending shaft 3 will increase. There were problems (disadvantages) such as the need for a large capacity and the large size of this part.

Therefore, the invention of the earlier application by the same applicant as the above-mentioned present application focuses on the problems (deficiencies) of such conventional devices, and the invention focuses on the problems (deficiencies) of such conventional devices, and the invention is based on The above problem can be solved by installing the flat plates at 180° symmetrical positions so that their surfaces are perpendicular to the axis, and differentially extracting the axial displacement or strain of the two flat plates caused by the Coriolis force. The article concerned a gyroscope device that solved the problem.

Therefore, the gist of the invention of the prior application is that a base, a shaft member rotatably attached to the base, and a surface substantially orthogonal to the axis of the shaft member coincide with each other; two strip-like members attached to the shaft member so that the longitudinal direction of the member is axially symmetrical with respect to the axis; and a detection device that differentially detects the deflection of the two strip-like members in the axial direction. and a drive device for applying alternating angular vibration (torsional vibration) around the axis to the base to the shaft member having the two strip-shaped members.

Hereinafter, in order to facilitate understanding of the present invention, first,
The invention of the prior application having the above-mentioned gist will be explained based on FIGS. 2 and 3.

FIG. 2 is a perspective view showing the gyro device according to the invention of this prior application. In the gyro device shown in FIG. 2, one end of a shaft 11 is rotatably attached to a base 10 so that the shaft 11 is approximately perpendicular to the base 10, and the other end is attached via a mounting member 12. , two thin plate-like members 13 and 13', for example, strip-shaped, are attached. In this case, the plate members 13, 13' are
These plate surfaces are substantially orthogonal to the axis (Z-Z) of the shaft 11, and their longitudinal directions are symmetrical with respect to the shaft 11. Plate member 13,
Weights 14 and 14' are attached to the free ends of 13', respectively. The angle detector 15 and the drive device 16 are connected to the axis 1.
The drive device 16 is driven by the output from the external drive amplifier 5, and the mounting member 1 is mounted around the mounting member 1.
2. Plate members 13, 13' and weights 14, 14'
around the axis (Z-Z) in the figure, the angular velocity ω
vibrate alternately. Displacement detectors 17, 17' are provided on the base 10 below the weights 14, 14',
The axis of the weights 14, 14' with respect to the base 10 (Z-
Z) direction displacement is detected. Note that due to design considerations, the weights 14, 14' are attached to the plate-like members 13, 1.
It can also be replaced by the weight of 3' itself.

Next, the operation of the gyro device of the prior application shown in FIG. 2 will be explained. Now, by the drive device 16, the weight 14
and 14' are moving in mutually opposite directions at a speed v, an angular velocity Ω to be measured is input around an axis (X-X) perpendicular to the axis (Z-Z) of the device, and the device Assuming that the whole body is rotating in inertial space, the weight 14 has an upward direction and a weight 1
A downward Coriolis force Fc acts on 4'. As a result, due to the flexibility of the plate members 13, 13',
A deflection amount Δx in the opposite direction as shown in FIG. 3 occurs in the plate members 13, 13'. Therefore, this is electrically detected by the displacement detectors 17 and 17', and their detection outputs are passed through the actuation amplifier 18 and then sent to the demodulator 7 to which the output of the displacement angle detector 15 is input. This makes it possible to obtain an output proportional to the input angular velocity Ω. That is, the angular velocity Ω can be detected. Note that the displacement detectors 17 and 17' also generate displacement outputs due to acceleration in the axis (Z-Z) direction, but these are canceled out by the operation amplifier 18 because the displacements are in the same direction. , it is not an output.

By the way, the drive devices of the devices of the conventional and prior inventions described above are both mechanically complex and
There was a problem in that the amplitude of vibration, which directly affects the output sensitivity of the device, could not be increased.

Therefore, the main object of the present invention is to provide a gyro device which eliminates the above-mentioned drawbacks.

The gyro device according to the present invention is characterized in that the gyro device detects angular velocity by alternately vibrating two thin plate-like force detection members on a base by a drive device, the drive device being It consists of a bimorph type piezoelectric element located at the center of two force detection members in the longitudinal direction and having a common surface and a surface orthogonal to each of the longitudinal directions, and one end of the bimorph type piezoelectric element is connected to the force detecting member. The other end of the mounting member of the detection member is attached to the base.

The present invention will be explained below with reference to FIGS. 4 to 6. Note that in FIGS. 4 to 6, the same reference numerals as in FIGS. 1 to 3 indicate the same elements, and detailed explanation thereof will be omitted.

FIG. 4 is a perspective view showing an example of the gyro device of the present invention. In the example of the present invention shown in the figure, two drive devices 35 and 36 each made of a rectangular bimorph piezoelectric element are installed approximately in the center of the base 10.
Both of those plate surfaces are substantially perpendicular to the plate surface of the base 10 on the same plane parallel to the drive axis (Z-Z), and there is a gap G between them that is approximately rectangular and extends in the vertical direction. It is fixed via the mounting members 35' and 36' so that it exists. Of course, the mounting members 35' and 36' may be omitted. A mounting member 3 having mounting portions 30-1 and 30-2 that intersect with each other in a cross shape and are fixed to each other.
One mounting part 30-1 of 0 is connected to both drive devices 35,
It is fixed to the free end, that is, the upper end of 36, and supports these upper ends. At the mounting portion 30-2 of the mounting member 30, which is located within the gap G between the two drive devices 35 and 36 and parallel to the input shaft (X-X), two substantially identical and bimorph strip-shaped bimorphs are mounted. Force detection piezoelectric element, force detection member or plate-shaped vibrating member 25 of the same size,
25', both of which are parallel to the input axis X-X,
Moreover, they are attached so that their plate surfaces are perpendicular to the plate surfaces of the piezoelectric elements of the drive devices 35 and 36. Therefore, the plate surfaces of the piezoelectric elements 25 and 25' for detecting both forces are as follows.
They are perpendicular to the upper surface (horizontal surface) of the base 10, that is, in a vertical plane, and there is a sufficient gap between their lower edges and the upper surface of the base 10, respectively.

Here, as shown in the figure, one of the driving devices 35 made of a bimorph type piezoelectric element includes two thin plate-shaped piezoelectric elements 35-1 and 35-3 and a thin metal plate made of a high-strength material sandwiched between the two piezoelectric elements 35-1 and 35-3. 35-2. In this example, one, e.g.
Although not shown, a signal from a drive amplifier similar to the example in FIG. 2, for example, an alternating voltage, is applied to the piezoelectric element 35-1 to drive the other piezoelectric element 35-
3 is used for detecting the declination angle, it is of course possible to use a detection device having another configuration for detecting the declination angle.

In FIG. 3, 26 is a lead wire that differentially connects the electrodes on the same side of one of the force detecting piezoelectric elements 25, 25'. Also, 27, 27' are
Each of them is connected to the input side of the amplifier 18' by a lead wire led out from each electrode on the other side of the same surface of the piezoelectric elements 25, 25' for detecting both forces. This amplifier 1
The output of 8' is supplied to demodulator 7. Although not shown, declination signals from the drive devices 35 and 36 are supplied to the demodulator 7 as reference signals via lead wires. Therefore, similar to the example of the earlier application mentioned above, the demodulator 7
The angular velocity Ω can be detected by the output.

In addition, in the above description, separate drive devices 35, 3
6 was used, but an integrated drive device having a gap G in the center may be used.

Next, the operation of the example shown in FIG. 3 will be explained with reference to FIG. 4. This FIG. 4 is for showing the operating principle of the driving devices 35 and 36 of the example shown in FIG. As shown in FIG. 4, the center line A-A of the width of the force detection piezoelectric elements 25, 25' is
5, 36 piezoelectric elements (hereinafter referred to as drive piezoelectric element 3)
5, 36) passing through the longitudinal center (0) of the part that causes bending deflection, and the mounting member 30
Each part is designed so that the center of gravity (0') in the vertical direction of the vibrating section consisting of the force-detecting piezoelectric elements 25 and 25' substantially coincides with the center (0).
Now, when an alternating voltage is applied to the drive piezoelectric element 35 as described above, the drive piezoelectric element 35 deforms as shown by the broken line B in FIG. The piezoelectric elements 25, 25' are
As shown by the chain line in the same figure, vibration of the angle of displacement φ is performed. In this case, it is designed so that the longitudinal center 0 of the drive piezoelectric element 35 and the center of the width of the force detection piezoelectric elements 25, 25', that is, the center of gravity (0') of the vibrating part, approximately coincide. Therefore, the entire vibrating section performs alternating vibration around the center of gravity (0').

That is, according to each of the above-mentioned examples, the drive device 35,
36 functions as a bearing device that allows the vibrating section consisting of the two force detection piezoelectric elements 25, 25' and the mounting member 30 to rotate only around its center of gravity (0'), and the above-mentioned function. It simultaneously functions as a drive device to give alternating vibrations to the vibrating part and as a displacement angle detector to detect the amplitude of the alternating vibrations, and has an extremely simple structure and minimum size. Various functions can be achieved depending on the number of parts.

Next, the operation of the example gyro device shown in FIG. 3 will be explained. Now, when the force detection piezoelectric elements 25 and 25' are moving in opposite directions at a speed v by the drive devices 35 and 36, the drive shaft Z-
Assuming that the angular velocity Ω to be measured is input around the input axis X-X perpendicular to Z, and the entire device is rotating at the angular velocity Ω with respect to the inertial space, the force detection piezoelectric element 25 , 25' are subjected to Coriolis forces Fc in opposite directions. As a result, a voltage in the opposite direction proportional to the magnitude of the Coriolis force Fc is generated in each of the force detection piezoelectric elements 25, 25'. These voltages are passed through the amplifier 18' via lead wires 27 and 27', and then passed through the demodulator 7.
As a result, an output proportional to the input angular velocity Ω can be obtained. That is, the angular velocity Ω can be detected. Incidentally, displacement output is also generated due to acceleration in the Z-Z direction of the drive shaft, but these are generated when the respective electrodes on the same side of the force detection piezoelectric elements 25, 25' are differentially connected by the lead wires 26. Since the two signals are connected to each other, they cancel each other out and are not output.

FIG. 5 is a perspective view showing still another example of the gyro device to which the present invention is applied. In the example shown in the figure, two thin plate piezoelectric elements 35A are used as drive devices, similar to one of the drive devices 35 in the example shown in FIG.
-1, 35A-3 and a thin metal plate 35A-2 made of a high-strength material placed between them, only one bimorph piezoelectric element 35A is used. In this case, only the central thin metal plate 35A-2 is further extended upward, and a mounting portion 30-1 of the mounting member 30 similar to the example shown in FIG. 3 is fixed to this extension C. still,
Force detection piezoelectric elements 25, 2 of this mounting member 30
A mounting portion 30-2 for mounting and supporting the force-detecting piezoelectric elements 25, 25' is formed downward in a saddle shape.
The center of the width, that is, approximately the center of gravity, and the metal plate 35A
The longitudinal center of the extension portion C of -2 is approximately aligned with the center of the extension portion C in the longitudinal direction.

A mounting member 30 and two force detection piezoelectric elements 25,
25' and the spring restoring action of the thin metal plate 35A-2, a signal with a frequency equal to the resonant frequency f ₀ of the alternating rotational amplitude around the drive shaft Z-Z is generated. , drive device 35
A, i.e. one piezoelectric element, e.g. 35A-1
When a voltage is applied to the vibrating part, a resonance phenomenon occurs in the vibrating part, and a large amplitude can be obtained with a small applied voltage. in this case,
Because high-strength material is used for the thin metal plate 35A-2,
Even if a large amplitude is applied to this, the thin metal plate 35A-2 will not be damaged due to fatigue due to repetition. That is, by utilizing the resonance effect between the thin metal plate 35A-2 and the vibrating part as a vibration amplification device, it is possible to obtain a large vibration width that is more than an order of magnitude larger than that of the above-mentioned device, and it can be used as a gyro. The sensitivity of
An effect that can be increased dramatically has been obtained.

In addition, other configurations and functions of the example shown in FIG. 5 are as follows.
Since it is almost the same as the example shown in FIG. 3, the explanation thereof will be omitted.

FIG. 7 is a perspective view showing the main parts of still another example of the present invention. The difference between this example and the example of FIG. It is in the structure of 30-2. In the example shown in FIG. 6, the mounting part is composed of two L-shaped parts 30-2 and 30'-2, and the surfaces 30-3 and 30'-3 of their respective legs are , they can be processed simultaneously as if they were on the same plane. Therefore, if the two force-detecting piezoelectric elements 25, 25' are attached to the planes 30-3, 30'-3 of the portions 30-2, 30'-2, respectively, the former surfaces are identical. It will be in a state where it is correctly aligned within the plane. In addition, in the illustrated example, the portions 30-2,
The legs of each of the force detecting piezoelectric elements 25, 25' are extended downwardly by a force detecting piezoelectric element 25, 25'.
This is to make the centers of gravity of the vibrating parts approximately coincide with each other.

As described above, the gyro device of the present invention has a much simpler structure than the conventional and prior art devices, but it achieves much better effects.

It will be apparent that many changes and modifications may be made by those skilled in the art without departing from the spirit of the invention as described above.

[Brief explanation of the drawing]

1 is a perspective view of a conventionally known tuning fork type vibrating gyro device, FIG. 2 is a perspective view of a gyro device of a prior application, and FIG. 3 is a schematic diagram for explaining the operating principle of the device shown in FIG. FIG. 4 is a perspective view of an example of the present invention, FIG. 5 is a schematic diagram for explaining the operation of the example of FIG. 4,
FIG. 6 is a perspective view of another example of the present invention, and FIG. 7 is a perspective view showing essential parts of still another example of the present invention. In the figure, 7 is a demodulator, 10 is a base,
25, 25' are piezoelectric elements for force detection, 26, 27,
27' is a lead wire, 30 is a mounting member, 35, 36,
35A is a drive device.

Claims (1)

[Scope of Claims] 1. In a gyroscope device that detects angular velocity by alternately vibrating two thin plate-like force detection members on a base using a drive device, the drive device detects the force detection members of the two force detection members. located at the center in the longitudinal direction of the member, and
A bimorph piezoelectric element having a surface perpendicular to a common plane in the longitudinal direction of the force detection members, one end of the bimorph piezoelectric element is attached to the mounting member of the force detection member, and the other end is attached to the base. A gyroscope device characterized by: 2. In the gyro device according to claim 1 above, the center of gravity of the vibrating section consisting of the two force detection members and the mounting member for the two force detection members is located approximately at the center of gravity of the two force detection members. It is characterized in that it coincides with the center of the width in the direction perpendicular to the longitudinal direction of the bimorph piezoelectric element serving as the detection member. 3. In the gyroscope device according to claim 1 above, the bimorph piezoelectric element as the driving device is composed of a thin plate made of a high-strength material at the center and thin plate-shaped piezoelectric elements provided on both sides of the thin plate. The present invention is characterized in that only the thin plate is extended in the longitudinal direction and combined with the attachment member of the force detection member.