JPH02268221A - Gyroscope apparatus - Google Patents

Abstract

PURPOSE:To eliminate defective conduction and capacitance change in piezoelectric elements and to stabilize performances by applying a conductive bonding agent at the central parts of the elements and applying an ordinary bonding agent around the central part, when the piezoelectric elements are bounded and fixed to hinges and a tuning fork. CONSTITUTION:When signal detecting piezoelectric elements 31-1 and 31-2 are bonded and fixed to hinge parts 30-1 and 30-3 of a hinge 30, a conductive bonding agent 51 is applied to the central parts of the bonding surfaces of the elements 31-1 and 31-2. An ordinary bonding agent 50 is applied around the bonding agent 51. Thereafter, the elements 31-1 and 31-2 are brought into contact with the hinge parts 30-1 and 30-3 tightly and fixed to the hinge parts. When piezoelectric elements for driving are bonded and fixed to both sides along the deflecting part and the base part of the tuning fork and when displacement detecting piezoelectric elements are bonded and fixed to the outer surface of the deflecting part of the tuning fork, the same procedure is performed. Thus, defective conduction at the bonding surfaces of the piezoelectric elements and electrodes, and capacitance change are eliminated, and the performances are stabilized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gyro device (angular velocity detection device) using a tuning fork.
Regarding.

[Conventional technology]

In a conventional gyro device using a tuning fork, as shown in FIG.
-1), (1-1), the flexible parts (1-2), (1-2) connected to these, and both the flexible parts (1-2
), a base (1-3) that connects each free end of (1-2)
and both flexible parts (1-2) from this base (1-3),
(1-2) A connecting part (
1-4).

In addition, (30) is a hinge, and this hinge (30) includes a central connecting part (30-2), and rectangular hinge parts (30-1) and (30-3) extending vertically from the central connecting part (30-2). A base or annular portion (30-4) that integrally connects and connects the free ends of the two hinge portions (30-1) and (30-3).
It consists of It is desirable that the hinge (30) be manufactured as a whole from a single plate by a method such as wire cutting. The hinge part (30-IL (30-3) has a tuning fork (1)
A piezoelectric element (31-1) for detecting the deflection that occurs in the tuning fork (1) and, therefore, in the hinge (30) due to the angular velocity Ω input around the input shaft (2-2).

(30-2) are respectively fixed with ordinary adhesive. Further, the connecting portion (30-2) of the hinge (30) is connected to the tuning fork (1).
It fits into the U-shaped recess (1-4a) of the connecting portion (1-4).

Further, at the base of the hinge (30), that is, at both open ends of the annular portion (30-4), there are provided a cylindrical body (41-1) having substantially the same shape and size with one end closed, (41- 2) Fix each opening airtightly. In this case, the axes of the annular portion (30-4), cylindrical bodies (41-1), and (41-2) are made to coincide with the tuning fork axis or the input axis (Z-Z), respectively. The closed ends (41-1a) and (41-2a) of the cylindrical bodies (41-1) and (41-2) are connected through the cylindrical elastic members (42-1) and (42-2). , L-shaped fittings whose lower ends are fixed to the mounting base (44), respectively (
43-1) and (43-2). In addition, in the above configuration, the center of gravity of the tuning fork (1) is located at the hinge (3).
0) so that it coincides with the center of both hinge parts (32-1) and (30-3), that is, the center of the connecting part (30-2),
Of course, each part of the tuning fork (1) is designed.

In addition, in Figure 2, (4aL (4a) is a tuning fork (1)
This shows a piezoelectric element that drives the .

FIG. 3 is an explanatory diagram for explaining the principle of the conventional example shown in FIG. 2, and shows the main parts thereof as viewed from the axis (ZZ) direction of FIG. 2. As shown in the figure, this gyro device has
When the angular velocity Ω is applied around the axis (2-2), the corresponding Coriolis force Fc is applied to both the vibrating masses (1-1),
(1-1) in parallel and opposite directions, and the resulting torque is applied to the hinge parts (30-1) and (30-3) via the connecting part (30-2) of the hinge (30). , as shown in the figure, causes an S-shaped bending deformation. In this case, the piezoelectric elements (31-1) and (31-2) are connected to the hinge portion (30-1) so that their polarization directions are opposite to each other, as indicated by + and - in the figure. , (30-
3), so the side piezoelectric layer (31-1),
The input angular velocity Ω is detected by short-circuiting (31-2) to make one output (45), and synchronously rectifying this with the voltage from the voltage source (5a) shown in Fig. 2 in the demoscillator (7). , thus a gyro device can be obtained.

Although not shown, an axis (Y-Y
) direction, the piezoelectric element (31-
The voltages induced at 1) and (31-2) have opposite signs, and there is no output from these.

Further, in order to avoid the influence of temperature, it is desirable to make the tuning fork (1) and the hinge (30) from a thermostatically elastic material.

FIG. 4 shows the hinge part (30-) of the hinge (30) mentioned above.
1) Piezoelectric element (31-1), (31
-2) is a perspective view for explaining a conventional method of fixing. As shown in the figure, in this conventional method, an ordinary adhesive (50) is applied to one side of the piezoelectric element (31-1) (or (31-2)), and the applied surface is attached to the hinge part (30-2).
1) By bringing the piezoelectric element (31-1) (or (31-3)) into close contact with (or (30-3)),
It's fixed on that. This also includes drive piezoelectric elements (4a), (4
When fixing a) with adhesive, and even if not shown, a tuning fork (11
) The same applies to the case where the piezoelectric element for displacement detection is adhesively fixed to the flexible portions (1-2) and (1-2) of (1-2).

[Problem to be solved by the invention]

However, in such a conventional gyro device, the hinge portions (30-1), (3
When fixing the piezoelectric elements (31-1) and (31-2) to the piezoelectric elements (31-1) and (31-2) using a normal adhesive (50), the piezoelectric elements (31-1) and (31-2) may 31
-1), the lower surface of (31-2) and the hinge part (30-1)
), (30-3), there are many cases where electrical continuity cannot be obtained between the piezoelectric element, the function as a piezoelectric element is no longer obtained, and the yield rate during production of the gyro device is also reduced. A similar problem also occurs when a piezoelectric element for driving and a piezoelectric element for displacement detection are adhesively fixed to the tuning fork (1).

Furthermore, in order to avoid the above problems, if only a conductive adhesive is used as the adhesive, the adhesive strength is insufficient, so the gyro performance changes greatly over time, making it impossible to obtain the desired gyro performance. There was a problem.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a novel gyro device that further solves the above-mentioned conventional problems.

[Means to solve the problem]

According to the present invention, a tuning fork, a detection piezoelectric element for detecting vibration of the tuning fork, a driving piezoelectric element for driving the tuning fork, a detection piezoelectric element, and a moment due to Coriolis generated in the tuning fork are detected. In the gyro device having a detection section, when each of the piezoelectric elements is fixed to the tuning fork or the detection section, a conductive adhesive is used in the center of the piezoelectric element to improve the yield of the bonding process. A gyro device is obtained.

[Effect] A piezoelectric element for driving a tuning fork.

When a detection piezoelectric element for detecting displacement and a signal detection piezoelectric element are adhesively fixed to the hinge part of the hinge, a conductive adhesive (51) is applied to the center of the piezoelectric element, and the conductive adhesive By applying an ordinary adhesive (50) around (51) and adhesively fixing the piezoelectric element, capacitance change due to aging of the piezoelectric element is prevented, and the yield and stability of the gyro are improved.

〔Example〕

FIG. 1 is a partially sectional perspective view of a main part of an embodiment of a gyro device according to the present invention. In the gyro device of the present invention, the configuration and operation other than those shown in FIG. 1 are the same as those of the conventional example shown in FIG. 2, even if not shown, and detailed explanation thereof will be omitted.

In the embodiment of the present invention shown in FIG. 1, piezoelectric elements (3
1-1) and (31-2), in the center of the adhesive surface of the piezoelectric elements (31-1) and (31-2),
After applying the conductive adhesive (51), a normal adhesive (50) is applied around the conductive adhesive (51), and then the piezoelectric elements (31-1), (31-2) are closely fixed to the hinge parts (30-1) and (30-3), respectively.

This also corresponds to the bending part (1-2) of the tuning fork (1), (1
-2) and the base (1-3), when piezoelectric elements for driving are adhesively fixed on both sides thereof, and when the bending part (1-2) of the tuning fork (1) is displaced on the outer surface of the (1-2). The same applies to the case where a piezoelectric element for detection is fixed with adhesive.

In the above description, the application and effects to a gyro device using a tuning fork have been explained, but for example, the dither hinge of a ring laser gyro.

The present invention is applicable to all devices having a structure in which a piezoelectric element is bonded to a metal member, such as an accelerometer using a piezoelectric element.

〔Effect of the invention〕

According to the present invention described above, when a piezoelectric element is adhesively fixed to a hinge and a tuning fork, a conductive adhesive is used in addition to a normal adhesive, so that the electrodes on the adhesive surface of the piezoelectric element and
Electrical conduction is reliably established between the bonded surface and the phenomena of poor conduction and capacitance changes in the piezoelectric element after bonding, which were the case in the past, are eliminated, and the performance of the gyro device is stable and the yield during production is improved. improves.

[Brief explanation of drawings]

Fig. 1 is a perspective view with a part of the main part of an embodiment of the present invention in cross section, Fig. 2 is a perspective view of a conventional gyro device with a part removed, and Fig. 3 is a route for explaining the principle thereof. 4 are sectional views of the main parts of FIG. 2. In the figure, (1) is a tuning fork, (30) is a hinge, (30
-1). (30-3) is the hinge part, (31-1), (3L2
) represents a piezoelectric element for detection, (4a) and (4a) represent a piezoelectric element for driving, (50) represents a normal adhesive, and (51) represents a conductive adhesive, respectively.

Claims (1)

[Claims] A tuning fork, a detection piezoelectric element that detects vibrations of the tuning fork, a drive piezoelectric element that drives the tuning fork, a detection piezoelectric element, and a detection section that detects a moment due to Coriolis force generated in the tuning fork. The gyro device is characterized in that when each of the piezoelectric elements is fixed to the tuning fork or the detection part, a conductive adhesive is used in the center of the piezoelectric element to improve the yield of the bonding process. A gyro device.