JPS5852428B2 - Mirror rotation control element - Google Patents

Description

[Detailed description of the invention] The present invention relates to a mirror rotation control element.

Moving coil type rotation devices such as coreless morphs have conventionally been available, and it is possible to use these rotation devices as rotation control elements.

When this rotating device is used as a rotation control element, the resonance amplitude in the primary resonance caused by the return spring becomes extremely large by one point, and the safety of the control system is greatly deteriorated.

Therefore, in order to improve stability, oil damping or the like can be considered as a method of applying damping.

However, this method has drawbacks such as oil leakage and temperature characteristics.

Furthermore, if the moving coil portion has low rigidity and is actually used, resonance will occur at a low frequency in the moving coil portion, deteriorating the phase characteristics as a control element.

The present invention was made to address this problem, and uses a short ring.

Short rings are used in linearly moving control elements, such as voice coils, but this linearly moving type has the following problems.

That is, when used as a rotating type, since the mechanism is for converting linear movement to rotation, a new load is generated, increasing the dead zone for control, and causing new vibrations.

It also deteriorates stability.

Another problem is that in voice coils and the like, the eddy current generated in the short ring flows in a direction around the cylinder, so in order to allow the eddy current to flow, the short ring must be a perfect cylinder, which increases costs.

The present invention aims to provide a rotary control element free from the above-mentioned drawbacks, and the present invention will be explained below based on the drawings showing an example of its implementation.

FIG. 1 is a cross-sectional view of the mirror rotation control element of the present invention.
2 is a light reflecting mirror, and 2 is a support for the light reflecting mirror 1.

3 is a rotating shaft of the light reflecting mirror 1, and 4 is a bearing for the rotating shaft 3.

5 is a cylindrical core magnet magnetized in a direction perpendicular to the axis of the rotating shaft 3, and 6 is a case outer cylinder arranged concentrically with the core magnet 5 and forming a closed magnetic path.

Reference numeral 7 denotes a case side plate that fixes the core magnet 5 and the case outer cylinder 6 in a fixed position.

Reference numeral 8 denotes a drive coil, which is wound so as to have a component in a direction parallel to the rotating shaft 3.

Coil support members 9 and 9' are used to connect the drive coil 8 to the rotating shaft 3.

The rotation shaft 3, drive coil 8, and coil support members 9, 9' serve as a coil rotation element.

10 is a return spring that returns the coil rotator to a fixed position.

In the present invention, in the coil support members 9 and 9' of the coil rotator, the coil support member 9' is made of a conductive material.

Alternatively, both the coil support members 9 and 9' are made of conductive material.

By making both the coil supporting members 9 and 9' of conductive material, the coil supporting members 9 and 9' can be integrally molded.

Coil support members 9 and 9b conductive materials include conductive resin, copper with low electrical resistance, aluminum with low specific gravity, and various other metal materials. There are magnetic materials.

Figure 2 shows the case where a conductive material in magnetic flux rotates.
It shows the state of electric current that is generated and flows within a conductive material.

a indicates the direction of magnetic flux, which in the case of the present invention is generated from the core magnet 5t in FIG.
forms a closed magnetic circuit.

b indicates the rotation direction of the coil support member 9', and C indicates the current generated and flowing through the coil support member 9/J made of a conductive material when the coil support member 9 rotates in a magnetic flux. It shows.

Due to the current C and the magnetic flux a, a force in an opposite direction proportional to the speed of the rotational movement is applied to the coil support member 9', and a damping effect is exerted on the movement of the coil support member 9'.

Figure 3 shows the phase characteristics, where the horizontal axis is the frequency,
The vertical axis shows the phase delay.

This figure shows vibrations having a secondary resonant frequency of frequency f1, where the broken line shows the vibration with almost no damping, and the solid line shows the vibration with sufficient damping.

FIG. 4 shows the amplitude characteristics in the case shown in FIG.

The horizontal axis shows frequency and the vertical axis shows amplitude, where the resonance frequency is fl, the broken line shows the case where the damping is not very strong, and the solid line shows the case where the damping is sufficiently strong.

If the damping is not very strong, the response characteristics will be poor and extremely unstable when used for control.

FIG. 5 shows the phase characteristics and amplitude characteristics when the vibration device has primary resonance and further has secondary resonance.

The left vertical axis shows the amplitude, the right vertical axis shows the phase delay, and the horizontal axis shows the frequency.

The solid line is the amplitude characteristic when damping is applied, the broken line is the phase characteristic when damping is applied and there is no secondary resonance, and the dashed line is the phase characteristic when there is secondary eutectoid at a low frequency. The two-dot chain line shows a part of the phase characteristic when there is primary resonance at a high frequency.

That is, in a case where secondary resonance occurs at a low frequency as shown by the dashed line, the phase is delayed by more than 1800 degrees at the low frequency as shown in the figure.

Therefore, as shown in the figure, only the control gain G1 can be obtained.

When there is a high-frequency I-secondary resonance as shown by the inverted two-dot chain line, a high control gain of 02 is obtained as shown in the figure, which is a desirable characteristic for control.

Therefore, higher control gain can be obtained by increasing the rigidity of the rotator and the like.

Next, FIG. 6 is a diagram showing the principle of operation.

d indicates magnetic flux, which is generated by the core magnet 5 in FIG.

e indicates the movement of the drive coil 8 when a current flows through the drive coil 8 in the magnetic flux d.

Furthermore, FIG. 7 shows a magnetic circuit when the coil support member 9' is made of a highly magnetic material.

When the coil support member 9 is not made of magnetic material, the gap in this magnetic circuit is e.

Conversely, when the coil support member 9' is made of magnetic material, the gap becomes e1+e2, and the gap can be made much smaller than when the coil support member 9' is not made of magnetic material.

If the gap can be made smaller, the magnetic flux acting on the drive coil can be increased.

Therefore, the current flowing through the drive coil can be reduced.

Furthermore, as shown in FIG. 2, since the eddy current does not go around the cylinder of conductive material, there is no need to pass the conductive material through a complete cylinder.

On the other hand, in a voice coil or the like, the eddy current goes around the cylinder, so the cylinder must be a perfect cylinder and cannot have any gaps.

Since the present invention can be implemented as described above,
The following great effects can be obtained.

IA By using a conductive material as the coil support member, damping can be applied to the movement of the rotator.

Thereby, the stability of the rotating device can be increased.

2) The rigidity of the drive coil portion can be increased.

Therefore, the frequency of secondary resonance can be increased as a characteristic, and the control gain of the rotating device can be increased.

3) By making the coil support member a metal with high conductivity, such as copper or aluminum, a higher damping effect can be obtained and stability can be improved.

In addition, the aluminum type can reduce the weight, reduce the moment of inertia, and increase the efficiency of the rotating device.

4) By using metal for the coil support member I, the rigidity of the rotor as a whole can be increased.

5) By forming the coil support member from a magnetic material, the magnetic circuit gap can be substantially reduced, so that the magnetic flux can be increased and the current flowing through the drive coil can be reduced.

In other words, efficiency can be improved.

6) By reducing the gap in the magnetic circuit and increasing the magnetic flux, the damping effect can be increased and the stability of the rotating device can be improved.

7) By using a conductive resin as the coil support member, damping can be achieved, and since the coil support member is made of resin, the rotor portion can be integrally molded.

Therefore, the rigidity of the rotor as a whole can be increased,
Also, the production process is easier.

8), Show) With the IJ tongue linear movement type, it was necessary to scrape the plate into a perfect cylinder, but with the rotary type I scraping of the present invention, it is not necessary to make the plate into a perfect cylinder, and the plate can be made into a round shape. It can be provided at low cost because it can be made from recycled materials.

Also, the processing method is free.

9) Since the torsional rigidity can be increased, the torsional vibration frequency can be increased, and the phase delay can be reduced, a high control gain can be achieved when used for control.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view, FIGS. 2 to 6 are explanatory diagrams of the operation, and FIG. 7 is an explanatory diagram showing an application example. In the figure, 1... Light reflecting mirror 2... Support body, 3... Rotating shaft, 4... Bearing, 5
... Core magnet, 6 ... Case outer cylinder, 1 ... Case side plate, 8 ... Drive coil, 9, 9' ... Coil support member, 10...
...It's a continuous f.

Claims (1)

[Claims] 1. a freely rotatable light reflecting mirror; a cylindrical core magnet magnetized in a direction perpendicular to the central axis of rotation of the light reflecting mirror and having an axis coinciding with the central axis of rotation of the light reflecting mirror; A case outer cylinder is arranged concentrically with the outer circumference of the core magnet to form a closed magnetic path with a gap therebetween, and a cylindrical part is located in the gap and one end is coupled to the reflecting mirror. a coil support member; a rotation drive coil disposed in the cylindrical portion i of the coil support member and having a coil whose component is parallel to the axis of the core magnet; and a return spring for returning the reflection mirror to a fixed position. A mirror rotation control element, wherein at least the cylindrical portion of the coil support member is formed of a conductive material.