JPH05126584A - Vibration gyro - Google Patents

Abstract

PURPOSE:To make a vibrator conduct a stable self-induced vibration by a method wherein driving voltages applied to separate piezoelectric elements are increased or decreased for regulation and thereby driving forces of the separate piezoelectric elements and voltages generated thereby are balanced. CONSTITUTION:In the case when an AC voltage for driving is supplied to a movable terminal 20 of a variable resistor 16 from a driving means for vibration, the movable terminal 20 is controlled so that a potential difference between terminals 5 and 9 and the one between terminals 6 and 10 be equal to each other, and thereby a resistance value of the variable resistor 16 is regulated. In other words, the respective output voltages of the terminals 9 and 10 show voltages which are distributed properly by the variable resistor 16 and impressed on separate piezoelectric elements 2 and 3, and a voltage difference between them becomes voltages generated by the piezoelectric elements 2 and 3 with a bending vibration of a vibrator. By regulating the variable resistor 16, accordingly, driving forces and the generated voltages for the vibrator by the separate piezoelectric elements 2 and 3 are balanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope for detecting an angular velocity, and more particularly to sufficiently stabilizing self-excited vibration.

[0002]

2. Description of the Related Art As a conventionally known vibrator used in a vibrating gyroscope, there is, for example, the one shown in FIG. In this structure, the vibrator 4 is formed by attaching piezoelectric elements 2 and 3 to two side surfaces of a vibrating body 1 having a quadrangular cross-sectional shape, which are adjacent to each other with one corner therebetween and are not parallel to each other. It is a thing. Here, as shown in FIG. 4 (b), the connection terminals 5 and 6 of the piezoelectric elements 2 and 3, respectively, together with the connection terminals 9 and 10 of the capacitive elements 7 and 8, are impedance elements Z ₁ and Z ₁ . ₃ and Z ₂ , Z ₄
Is connected to the connection terminal 11 via the, and the connection terminal 11 is further connected to a vibration driving means (not shown).

In the operation of such a vibrating gyro, the vibrating driving means applies a driving voltage to the piezoelectric elements 2 and 3 of the vibrating element 4 through the impedance elements Z ₁ and Z ₃ to cause the vibrating element 4 to move. Is an arrow in Fig. 4 (a)
Flexural vibration starts in the direction indicated by 12. Therefore, the piezoelectric element 2
And the impedance element Z ₁ of the connection terminal 5 and the capacitive element 7 and the impedance element Z ₂ of the connection terminal 9, respectively, the operation output, the piezoelectric element 3 and the impedance element Z.
A loop of self-excited vibration is formed by feeding back the connection terminal 6 with ₃ and the capacitive element 8 and the differential output of each of the connection terminals 10 with the impedance element Z ₄ to the vibration driving means. The child 4 continuously vibrates in the direction of the arrow 12. Such an oscillator 4 is indicated by an arrow 14 in the figure.
When rotated in the direction indicated by, Coriolis force is generated,
The vibrator 4 also flexurally vibrates in the direction of the arrow 13 in the figure, so that a difference occurs in the voltage generated between the piezoelectric elements 2 and 3, whereby the angular velocity can be measured.

[0004]

However, in the vibrating gyroscope as described above, if the driving force and the generated voltage of the respective piezoelectric elements differ due to the difference in the piezoelectric constants and the error in the dimensions, it is possible to achieve a good balance. In addition, it is not possible to cause the flexural vibration, and the vibrator cannot perform stable self-excited vibration.

An object of the present invention is to adjust the driving voltage applied to each piezoelectric element to adjust the driving force and the generated voltage of each piezoelectric element effectively, so that stable self-excited vibration of the vibrator is achieved. It is intended to provide a vibrating gyro capable of performing the above.

[0006]

The vibrating gyroscope of the present invention comprises:
A first impedance element in which two sets of piezoelectric elements are attached to at least one side surface of a vibrating body having a polygonal transverse cross section to form a vibrator, and one set of piezoelectric elements is connected in series.
A parallel connection part with a second impedance element serially connected to one capacitive element, a third impedance element serially connected to the other set of piezoelectric elements, and a third impedance element serially connected to the other capacitive element. A variable resistor is connected to each of the parallel connection portions with the impedance element 4 and the movable terminal of the variable resistor is connected to the vibration driving means of the piezoelectric element.

This will be described more specifically with reference to FIGS. 1 and 2. In the figure, the same parts as those described in the related art are indicated by the same numbers. In this vibrating gyroscope, for example, as shown in FIGS. 1 (a) and 1 (b), two sets of piezoelectric elements are provided on two side faces of a vibrating body 1 having a polygonal cross-sectional shape and adjacent to each other with one corner portion. When 2 and 3 are attached to form the vibrator 4, as shown in FIG.
The other end of the first impedance element Z ₁ whose one end is connected to the piezoelectric element 2 of one set and the other end of the second impedance element Z ₂ whose one end is connected to the first capacitive element 7 are mutually connected. To the connecting point, one fixed terminal 18 of the variable resistor 16 is connected, and the other end of the third impedance element Z ₃ whose one end is connected to the piezoelectric element 3 of the other set, and the second capacitive element. The other fixed terminal 19 of the variable resistor 16 is connected to the connection point where the other end of the fourth impedance element Z ₄ whose one end is connected to 8 is mutually connected, and the variable resistor 16
The movable terminal 20 is connected to a vibration driving means (not shown).

[0008]

According to this vibrating gyro, the drive voltage applied to each piezoelectric element 2 and 3 can be adjusted by adjusting the resistance value of the variable resistor 16 by moving the movable terminal 20. Therefore, the driving force and the generated voltage of each piezoelectric element can be made sufficiently equal to make the bending vibration of the vibrator well balanced, and stable self-excited vibration can be provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 (a) to 1 (d) are diagrams showing a configuration example of a vibrator applicable to the vibration gyro of the present invention. The one shown in FIG. 1 (a) is a vibrating body 1 having a rectangular cross section,
By bonding piezoelectric elements 2 and 3 to two adjacent side surfaces with a corner therebetween, a vibrator 4 similar to that described with reference to FIG. 4 (a) showing a conventional example is configured. In No. 4, the piezoelectric elements 2 and 3 are made to function as piezoelectric elements for driving, returning, and detecting by the method described in Japanese Patent Application No. 3-162331.

Here, in the vibrating gyroscope of the present invention, as shown in FIG. 2, the impedance element Z ₁ is connected in series to the connection terminal 5 of the piezoelectric element 2, and the impedance element is connected to the connection terminal 9 of the capacitive element 7. Z ₂ is connected in series, and these series connection parts are connected in parallel to each other, and the variable resistor 16 is connected to the connection point of both impedance elements Z ₁ and Z _2.
One of the fixed terminals 18 is connected. The piezoelectric element 2
And the other end of the capacitive element 7 are grounded. Similarly, the impedance element Z ₃ is connected in series to the connection terminal 6 of the piezoelectric element 3, the impedance element Z ₄ is connected in series to the connection terminal 9 of the capacitive element 8, and these series connection parts are connected in parallel with each other. Then, the other fixed terminal 19 of the variable resistor 16 is connected to the connection point between the impedance elements Z ₃ and Z ₄ . Then, again, the other end of the piezoelectric element 3 and the other end of the capacitive element 8 are grounded. Further, the movable terminal 20 of the variable resistor 16 is connected to a vibration driving means (not shown).

In the vibrating gyroscope constructed as described above, when the driving AC voltage is supplied to the movable terminal 20 of the variable resistor 16 from the vibration driving means, the piezoelectric element 2 and the impedance element Z ₁ are connected. The voltage difference between the terminal 5 connected to the point and the terminal 9 connected to the connection point between the capacitive element 7 and the impedance element Z ₂ , and the terminal 6 connected to the connection point between the piezoelectric element 3 and the impedance element Z _3. Then, the movable terminal 20 is controlled so that the voltage difference between the terminal 10 connected to the connection point between the capacitive element 8 and the impedance element Z ₄ becomes equal, and the resistance value of the variable resistor 16 is adjusted. According to this, the output voltage of each of the terminals 9 and 10 is
The variable resistor 16 shows the voltage properly distributed and applied to the respective piezoelectric elements 2 and 3, and the piezoelectric element 2 in which the voltage difference is generated by the bending vibration of the vibrator 4 is generated.
The generated voltages are 3 and 3. Therefore, by adjusting the value of the variable resistor 16, the driving force and the generated voltage of the vibrator 4 by the respective piezoelectric elements 2 and 3 can be well balanced.

The above-described impedance adjustment configuration has a vibrating body 1 having a triangular cross section as shown in FIG. 1 (b).
Piezoelectric elements 2 and 3 are attached to two adjacent side surfaces of the vibrator 4
, And as shown in Figure 1 (c),
The same can be applied to the vibrating body 4 in which the piezoelectric elements 2 and 3 formed by electrode division are attached to one side surface of the vibrating body 1 having a quadrangular cross-sectional shape.

Further, as shown in FIG. 1 (d), piezoelectric elements 2 and 3 are attached to two adjacent side surfaces of a vibrating body 1 having a quadrangular cross section, and the other adjacent two side surfaces of the vibrating body 1 are attached. Piezoelectric elements 2 ′ and 3 ′ are attached to form a vibrator 4, and the piezoelectric element 2 and the piezoelectric element 2 ′ on the side facing the piezoelectric element 2 are provided.
Are connected in parallel, and similarly, the piezoelectric element 3 and the piezoelectric element 3 ′ on the opposite side are connected in parallel to form a pair, and impedance elements Z ₁ and Z ₁ are connected as shown in FIG.
Connect to ₃ .

[0014]

With the above-described structure, the driving voltage applied to each piezoelectric element can be adjusted, and the driving force of the piezoelectric element and the generated voltage can be well balanced. Therefore, stable self-excitation can be achieved. Vibration can be obtained.

[Brief description of drawings]

FIG. 1A is an explanatory view illustrating the configuration of a vibrator applied to the vibration gyro of the present invention, and FIG. 1B is an explanatory view illustrating another structure of the vibrator applied to the vibration gyro of the present invention. FIG. 6C is an explanatory view illustrating still another configuration of the vibrator applied to the vibration gyro of the present invention, and FIG. 6D is a view of the vibrator applied to another embodiment of the vibration gyro of the present invention. It is explanatory drawing which illustrates a structure.

FIG. 2 is a connection layout diagram showing an embodiment of the vibration gyro of the present invention.

FIG. 3 is a connection layout diagram showing another embodiment of the vibration gyro of the present invention.

FIG. 4A is an explanatory diagram showing a configuration of a vibrator of a conventional vibrating gyro, and FIG. 4B is a connection arrangement diagram for explaining an operation of the conventional vibrating gyro.

[Explanation of symbols]

1 Vibrating body 2, 2a, 3, 3a Piezoelectric element 4 Oscillator 7, 8 Capacitance element Z ₁ , Z ₂ , Z ₃ , Z ₄ Impedance element 16 Variable resistor 20 Movable terminal

Claims (1)

[Claims] 1. A first impedance in which two sets of piezoelectric elements are attached to at least one side surface of a vibrating body having a polygonal cross-sectional shape to form a vibrator, and one set of piezoelectric elements is connected in series. Element and a second impedance element connected in series to one capacitive element in parallel, a third impedance element connected in series to the other set of piezoelectric elements, and a series connected to the other capacitive element A vibrating gyroscope in which a variable resistor is connected to each of the parallel connection portions with the connected fourth impedance element, and a movable terminal of the variable resistor is connected to a vibration driving means of the piezoelectric element.