JP2599395B2 - Tuned Dry Gyro - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuned dry gyro, and more particularly to a flexure hinge mechanism which is an important component of the tuned dry gyro, in which gimbal unbalance and mistuning are applied. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuned dry gyro structure capable of processing and assembling a gyro with a high degree of accuracy by providing a simple and easy adjusting means.

[Conventional technology]

The tuned dry gyro generally has the structure shown in FIG. 4, and has an inner flexure hinge 3a, a gimbal 8, and an outer flexure connected to a shaft 2 which is rotationally driven by a motor 1 in a case 5. A gyro rotor 4 is provided via a hinge 3b, and the gyro rotor 4 is a gyro serving as a sensing element forming a gyro input shaft and a gyro output shaft. Case 5
A pick-off 6 for detecting output from an output shaft and other torquer devices 7 are provided therein. The structural characteristics of this tuned dry gyro can be summarized in that, unlike an integrating gyro, the gyro rotor 4 and the motor 1 for driving the gyro rotor are separated. The most important component of the tuned dry gyro is the flexure hinge mechanism 3 having the flexure hinges 3a and 3b and the gimbal 8,
The three-dimensional view of the structural model is clearly shown in FIG.

The function of this flexure hinge 3 is that the gyro rotor 4
With the support of the tuned gyro, it determines one of the kinematic conditions for an ideal free gyro, which is why it is positioned as the most important component of the tuned gyro.

In the configuration of FIG. 5, assuming that the spring constants of the hinges 3a and 3b are K, the moments of inertia around the x-axis and y-axis of the gimbal are a and b, and the moments of inertia around the z-axis are c, (1/2) ・ (a + b-
It generates the equivalent spring force represented by c) · N ^2. This is to balance the spring force of the flexure hinge mechanism 3, which is a mechanical spring body, with the gyro rotor 4 'so as to act in the direction of offsetting the gyro rotor 4' from the zero point.
Can function as a free rotor.

Therefore, At this time, the tuned dry gyro says that tuning has been achieved, and the spin rate N of the gyro rotor 4 'at this time is called a tuning frequency.

The conditions under which the tuned dry gyro becomes a free rotor are briefly described above, but the operating principle of the tuned dry gyro will be described in more detail by a motion method.

The equation of motion of the tuned dry gyro is already described in the literature and will not be described in detail. However, here, the general formula of the tuned dry gyro derived by Craig and RJG is expressed as a single gimbal system (actually, Most tuned dry gyros have a single gimbal)
And in a real tuned dry gyro, 2N
Since the micro-vibration term is hardly a problem, ignoring this results in the following equation of motion.

I _XY + D _{q XY} + K _N θ _XY −j (H _{1 XY} + T _q θ _XY ) = − I _XY + jH _{0 XY} + M _XY …… (1) And H ₀ and H ₁ each represent angular momentum. Generally, since the moments of inertia a, b, and c of the gimbal are smaller than the moments of inertia A, B, and C of the gyro rotor by two or more digits, H ₀
H ₁ = CN = H. Rewriting equation (1) under these conditions gives equation (2).

I ( _XY + _XY ) −jH ( _XY + _XY ) = δT _IXY + δT _QXY + δR _RXY + M _XY (2) where δT _IXY , δT _QXY , and δR _RXY are respectively It is. The symbols in the expressions (2) and (3) are as follows.

I = (1/2) · (A + B + a) M X, M Y; torque applied from the outside to the gyro rotor, ND; torque by aerodynamic effects acting on the gyroscope rotor, T _D; drag torque acting on the gyroscope rotor, D; damping coefficient around flexure hinge, hinge torsion axis x, y, D _R : damping coefficient between rotor / case working in a direction perpendicular to gyro rotor rotation axis, θ _X , θ _Y ; case coordinate system X , The displacement angle (offset angle) of the gyro rotor relative to the case decomposed into Y, φ _X , φ _Y ; the absolute angle of the case decomposed into the case coordinate system.

In each of the above symbols, when the suffix is attached as theta _XY means a complex number _{(θ XY = θ X + jθ} Y), the same phi _XY, also M _XY.

Note that _MXY includes an error torque such as a mass unbalance torque generated when an external acceleration is applied (including a vibration acceleration).

From equations (2) and (3), if the tuned dry gyro is designed and manufactured so that K _N = T _q = D _q = 0, then θ _XY −φ _XY when M _XY is zero. It operates as a free gyro having two degrees of freedom.

Also added to rebalance circuit in this state, it is allowed to act on the gyro rotor as a torque proportional to M _D to theta _D theta
_{Since D} is detected in proportion to _D , it operates as a rate gyro. Here, the suffix D in the above represents either the X or Y axis.

[Problems to be solved by the invention]

Ideally, the tuned dry gyro is designed and manufactured so that the torque becomes zero as shown on the right side of the equation (2). In particular, δT _{IXY in} equation (2)
Is the mistuning torque, which depends on the design of the flexure hinge / gimbal mechanism. A point to be noted in the design of this flexure hinge mechanism is that if there is a gimbal unbalance torque (torque due to mismatch between the torsion axis of the flexure hinge and the center of gravity of the gimbal), an external 2N angular vibration is applied. If this is done, a 2N rectification error will occur. In order to solve this problem, in the case of Japanese Patent Publication No. 56-9647, a method is proposed in which two compensating weights are used for the gimbal.

According to Japanese Patent Publication No. 56-9647, it is possible to compensate for mistuning and gimbal unbalance torque by using the compensation weight and the spring rate compensation rod.

However, with the two gimbal unbalance compensation weights and the spring rate compensation rod, the mistuning torque and the gimbal unbalance torque cannot be separated well, and an extremely long time is required for the adjustment. In order to separate the gimbal 4 ", when the gimbal 4" is rotated by an adjustment method using two gimbal unbalance compensation weights 9a and 9b as shown in FIG. As shown in the figure for the two phase positions of 0 ° and 180 °, 1N torque is applied to the gyro rotor from FIG. 5 showing a model of the flexure hinge mechanism of the tuned gyro. Will be.

M _XY = m · r · N ² · δ · e ^jNt where, m: weight of weight, r: radius of rotation of weight, N: number of rotations of gimbal, δ: CG point of gimbal and CG of weight This is an unfavorable phenomenon in terms of the output noise of the tuned gyro, since the gyro rotor generates a modulation output as shown in FIG.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional tuned dry gyro, and has a flexure that can adjust three points of mistuning torque adjustment, gimbal unbalance torque adjustment, and modulation. The purpose is to obtain a hinge mechanism.

[Means for solving the problem]

In the flexure hinge mechanism according to the present invention, four adjusting screws are provided on a gimbal which is a component of the mechanism, and the four screws are adjusted and moved with respect to the gimbal to adjust the gimbal balance torque and mistuning. And prevents the occurrence of modulation.

That is, according to the present invention, a tuned dry drive provided with a flexure hinge mechanism formed by coupling an inner flexure hinge coupled to a rotation shaft and an outer flexure hinge coupled to a gyro rotor via a gimbal. In the gyro, four screw holes drilled on the gimbal of the flexure hinge mechanism at a certain interval on the same circumference around the geometric center of the gimbal, respectively, in the axial direction of the rotation shaft. The tune is provided in the same direction as the above, and is provided with four adjusting screws screwed into the four screw holes, which can be screw-displaced from the outside and can be exchanged for length adjustment as required.・ Provides dry gyros.

(Operation)

The method of using the four screws in the present invention is as follows.
Adjust gimbal unbalance torque. This adjustment is 2
The adjustment is made by raising or lowering the four or four screws by the same amount in the same direction.

 Next, the mistuning torque is adjusted.

In this case, the adjustment is performed by pairing two opposed screws. That is, when two screws are pulled up by the same amount in the same direction, the other two opposite screws are adjusted by moving the same amount in the opposite direction. In this method, no modulation occurs because two opposite screws move by the same amount. Hereinafter, the present invention will be specifically described based on embodiments shown in the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 and FIG. 3 show a sectional view and a plan view of the flexure hinge of the present invention.

The flexure hinge mechanism 12 of the tuned dry gyro is provided to support the gyro rotor 10 as described above, and the gyro rotor 10 includes an inner rotor 14,
An outer rotor 16, a balance ring 20, and a balance screw 22 are provided. Further, 24 is a torquer inner and outer ring magnet, 26 is a return pass ring, and 28 is a pick-off return pass ring.

The structure of the flexure hinge mechanism 12 must withstand all accelerations and directions acting on the gyro rotor 10.

Therefore, the structure of the flexure hinge mechanism 12 of the present embodiment shown in FIG. 2 is designed so that the inner flexure hinge 30 can receive a load in the direction along the axis of the shaft into which the inner flexure hinge 30 is inserted. 32 is configured to receive a load in a direction perpendicular to the shaft.
The gimbal 34 of the flexure hinge mechanism 12 can be generally regarded as a flat plate, and as a result, a ₀ + b ₀ c ₀ , so that four notches are formed at the upper ring 36 of the outer flexure hinge 32.
The gimbal 34 has a structure in which the gimbal 34 can be seen from the outside. The gimbal 34 is provided with screw holes 40 drilled in the axial direction on the same pitch circle, and the four adjustment screws 42 (the (See Fig. 1). These adjusting screws 42 are vertically adjusted within the screw holes 40 during adjustment.

In this embodiment, in order to achieve K = − (a + bc) −N ² , the gimbal inertia of the inner flexure hinge 30 and the gimbal inertia of the four adjustment screws 42 attached to the outer flexure hinge 32 are set. Involved.

Design K = - a (a + b-c) N 2, first four center-of-gravity position of the adjustment screw 42 is set by vertical movement to match the center of gravity of the gimbal 34. In this state, 2N vibrations are applied to the tuned dry gyro perpendicularly to the spin axis at two G levels from the outside, and all four or any two adjusting screws 42 are moved to each of them. An adjustment is made so that the error output that appears with the vibration becomes zero.

 Next, adjustment of mistuning is started.

Since the moment of inertia C around the δ axis in the above equation is a fixed value unless the length of the screw 42 is changed, the moments of inertia a and b (usually a = b) are adjusted.

For example, to adjust mistuning in design,
Assuming that a and b should be adjusted in the increasing direction, one screw may be pulled up and the other screw may be pulled down by the same amount as the amount of pulling. This can be done fairly accurately by specifying the screw speed, if the screw pitch is properly selected in advance. Further, when the above a and b are in the decreasing direction, it becomes possible by adjusting the weight. Further, the flexure hinge mechanism 12 is configured such that the inner flexure hinge 30 can penetrate the shaft, and is thus designed to facilitate the stop adjustment of the tuned / dry gyro.

〔The invention's effect〕

As described above, according to the present invention, the configuration is such that the mistuning torque and the adjustment of the gimbal unbalance torque can be performed independently of each other, so that the adjustment time is shorter than the conventional one, and as a result, By reducing the man-hours for processing and assembling, the price of the apparatus can be reduced, and there is an effect that a highly accurate tuned dry gyro can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a gyro rotor portion of a tuned dry gyro according to an embodiment of the present invention, and FIGS.
FIG. 1 is a sectional view and a plan view of an embodiment of a flexure hinge mechanism according to the present invention. FIG. 4 is a sectional view illustrating a general configuration of a conventional tuned dry gyro. FIG. FIGS. 6 to 8 are a schematic diagram and a graph illustrating a balance adjusting means of a conventional flexure hinge mechanism. 10… gyro rotor, 12… flexure hinge mechanism,
30 Inner flexure hinge, 32 Outer flexure hinge, 34 Gimbal, 40 Screw hole, 42 Adjustment screw.

Claims (2)

(57) [Claims] 1. A tuned dry gyro having a flexure hinge mechanism formed by coupling an inner flexure hinge coupled to a rotating shaft and an outer flexure hinge coupled to a gyro rotor via a gimbal. Four screw holes drilled on the gimbal of the flexure hinge mechanism at a predetermined interval on the same circumference around the geometric center of the gimbal, respectively, in the same direction as the axial direction of the rotating shaft. Provided, the four adjusting screws screwed into the four screw holes can be screw-displaced from the outside, and can be exchanged for length adjustment as required,
A tuned dry gyro characterized by being provided. 2. An upper ring attached to an outer flexure hinge of the flexure hinge mechanism is provided with four notches, through which the adjustment screw can be easily inserted and adjusted by screw displacement from the outside. The tuned dry gyro according to claim 1, wherein