JP2001218445A - Oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a small size oscillator support structure that is suitable for oscillating a scanning mirror of a laser scanning apparatus and a sub-mirror of a radio telescope. SOLUTION: This structure is composed of a rotor 12 that is fixed to a sub-mirror 2 supported to oscillate and is curved like an arc and a stator 14. The magnetized first teeth 22 are arranged at a constant pitch at the external circumference surface 16 of rotor 12 and the stator 14 includes a base material 24, a plurality of cores (26 and others) arranged on the base material 24 and a coil 36 wound to each core. At the end of each core, the second tooth 38 is arranged with the same pitch as the first tooth 22, the second tooth 38 of each core is provided opposed to the first tooth 22 by forming a gap between the first tooth 22 of the rotor 12, and when one second tooth 38 of the adjacent two cores is provided opposed to the first tooth 22, the second tooth 38 of the other core is displaced by almost 1/4 the pitch of the second tooth 38 from the opposing position for the first tooth 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing structure suitable for swinging a mirror constituting a scanning mirror of a laser scanning device or a sub-mirror of a radio telescope, for example.

[0002]

2. Description of the Related Art For example, in a radio telescope, a sub-mirror is provided in front of a main mirror, and the sub-mirror is swung in front of the main mirror. Generally, a swinging structure of a sub-mirror is supported in front of a primary mirror via a plurality of stays, and the sub-mirror is configured to be swingably supported and swung by the swinging structure. .

[0003]

Therefore, it is desirable that the swinging structure of the secondary mirror be as small as possible so that the primary mirror can receive as many radio waves as possible, and if possible, it will fall within the contour of the secondary mirror. Ideally, it should be large.
The present invention has been made to solve such a problem, and an object of the present invention is to provide an oscillating structure that can be made compact and, in a radio telescope, can be contained within the contour of a sub-mirror. It is in.

[0004]

In order to achieve the above object, a swing structure according to the present invention comprises a swingable body, a support for swingably supporting the swingable body, and a support fixed to the swingable body. , A stator fixed to the support, and first magnetic teeth provided on the rotor.
The stator includes a base fixed to the support, a plurality of cores made of a magnetic material provided on the base, second teeth respectively formed on the plurality of cores, and And a wound coil. A plurality of the first teeth are provided at a constant pitch along a circumferential direction of the virtual arc so that the tip of the first tooth is located in the virtual arc centered on the center of the swing of the swingable body. . The plurality of core portions are erected from the base at intervals in the circumferential direction of the virtual arc, and the second teeth are provided at the tip of each core portion along the circumferential direction of the virtual arc. A plurality of teeth are provided at the same pitch as the first teeth. The plurality of first teeth and the plurality of second teeth of each core portion face each other with an equal gap in the radial direction of the virtual arc, and are adjacent to each other.
When the second tooth of one of the core portions is directly opposed to the first tooth of the rotor, the second tooth of the other core portion of the two core portions is the first tooth. Are provided so as to be shifted in the circumferential direction of the imaginary arc with respect to the teeth of. Further, there is provided control means for sequentially selecting a core portion in which the second tooth is displaced from the first tooth and energizing the coil.

In the oscillating structure according to the present invention, when the second tooth is deviated from a position directly opposite to the first tooth of the rotor by the control means, the coil is supplied with an appropriate current polarity by the control means. , The first tooth of the magnetic rotor is the second tooth
For example, due to a magnetic attraction force acting between the second tooth and the second tooth, the second tooth moves until the second tooth is directly opposed to the second tooth. Thus, the rotor swings with the swingable body. That is,
With the same principle as that of the pulse motor, if the core part with the second tooth displaced is sequentially selected and the coil is energized with an appropriate current polarity, the object to be swung is accurately swung with the rotor by a desired angle. Can be. And in the swing structure of the present invention,
Since the rotor is directly fixed to the oscillating body and the driving means of the oscillating body is integrated with the oscillating body, for example, a single pulse motor is separately provided as in the related art,
Compared to the case where the swingable body is driven via a coupling mechanism,
The swinging structure can be made extremely compact.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an example of a swing structure according to the present invention, FIG. 2 is a sectional side view taken along line AA ′ in FIG. 1, and FIG. 3 shows a rotor constituting the swing structure according to the embodiment. FIG. 4 is a front view of the rotor,
5 is a side view of the rotor, FIG. 6 is a perspective view showing a stator constituting the swing structure of the embodiment, FIG. 7 is a front view of the stator, FIG. 8 is a side view of the stator, and FIG. It is a fragmentary front view which shows the principal part of.

As shown in FIGS. 1 and 2, the oscillating structure of the embodiment, as an example, oscillates and supports a sub-mirror 2 of a radio telescope. The secondary mirror 2 is supported on an upper part of a gantry 4 (corresponding to a support in the claims) so as to be swingable around a virtual straight line connecting both steel balls via two steel balls 6 (FIG. 2). I have. The surface of the sub mirror 2 on the side opposite to the gantry 4 is formed in a convex shape, and has a mirror surface 8.

The swing structure 10 according to the present embodiment includes a rotor 12 and a stator 14. The rotor 12 has a bolt 12 </ b> A
The main part of the outer peripheral surface 16 extends along the virtual arc, and the center of the virtual arc is the center C of the swing of the secondary mirror 2.
Almost matches. As shown in FIGS. 3 and 4, the rotor 12 includes a permanent magnet 18 and a magnetic member 20 that contacts the permanent magnet 18.
The surface opposite to 8 constitutes the outer peripheral surface 16 of the rotor 12, and the permanent magnet 18 extends in an arc shape with the magnetic member 20. A plurality of first teeth 22 are provided on the outer peripheral surface 16 of the rotor 12.
Are arranged at a constant pitch in the extending direction of the outer peripheral surface 16 and have a fan shape. These first teeth 22 are magnetized by the action of the permanent magnet 18 and become N poles or S poles. I have.

On the other hand, as shown in FIG. 1 and FIG.
Are formed on the bottom inside the gantry 4. As shown in FIGS. 6 to 8, the stator 14 includes a base 24 and a plurality of cores made of a magnetic material arranged upright on the base 24 at intervals from each other and arranged in the extending direction of the outer peripheral surface of the rotor. Portions 26, 28, 30, 32, and 34, and a coil 36 wound around each core portion. At the tip of each core portion, a plurality of second teeth 38 are substantially similar to the first teeth 22. They are provided at the same pitch in the direction in which the outer peripheral surface 16 extends. The second of each core portion 26, 28, 30, 32, 34
The teeth 38 face the first teeth 22 by forming the same gap in the radial direction of the outer peripheral surface 16 between the teeth 38 of the rotor 12 and the first teeth 22 of the rotor 12, and each of the core portions 26, 28, 30 , 3
Control means 40 for energizing the coils 36 of the two and 34 are provided.

When one second tooth 38 of two adjacent core portions faces the first tooth 22 of the rotor 12, the second tooth 38 of the other core portion becomes the first tooth 38. Teeth 22
Of the pitch of the second teeth 38 from the position directly opposite to
It is displaced by 4 in the direction of arrangement of the teeth. More specifically, in the present embodiment, when the second teeth 38 of the core portion 30 erected in the center are directly opposed to the first teeth 22 of the rotor 12 as shown in FIG. The second teeth 38 of the core part 26 are, for example, １ ／ to the left in FIG.
The second teeth 38 of the core portion 28 are displaced by a pitch with respect to the first teeth 22 by, for example, 1/4 pitch to the left in FIG. 1. At this time, the second
Of teeth 38 in the opposite direction to first teeth 22
The second teeth 38 of the core portion 34
Is displaced by ピ ッ チ pitch with respect to the tooth 22 of the first embodiment.

Next, the oscillating structure 10 constructed as described above is used.
The operation of will be described. When the rotor 12 is not swinging as shown in FIG.
0, the second tooth 38 is connected to the rotor 12 as shown in FIG.
Of the first tooth 22. Therefore, at this time, the second teeth 38 of the core portion 28 are 1/1 with respect to the first teeth 22.
It is displaced to the left by four pitches. Therefore, the control unit 40 supplies electricity to the coil 36 of the core unit 28 to
8 is magnetized and its second tooth 38 becomes, for example, an N-pole. If the first tooth 22 is magnetized, for example, to an S-pole, the second tooth 38 of the core 28 and the rotor 12 are rotated. The suction force acts between the first tooth 22 and the rotor 12, and the rotor 12
The first tooth 22 swings to a position directly opposite the second tooth 38 of the core 28, and thus swings clockwise in FIG. 1 by an angle corresponding to a quarter pitch.

Next, in this state, the second teeth 38 of the core portion 30 are displaced rightward by 1/4 pitch with respect to the first teeth 22. When the current to the coil 36 is eliminated and the coil 36 of the core 30 is energized with the opposite current polarity to magnetize the core 30, the second teeth 38 of the core 30 become S poles, A repulsive force acts between the second tooth 38 and the first tooth 22 of the rotor 12, and the rotor 12 is configured such that each of the first teeth 22 is located between the two adjacent second teeth 38 of the core 30. It swings further by the same angle in the same direction as the previous time until it reaches the position.

The second tooth 38 of the core 32 is
Is displaced leftward by 1/4 pitch with respect to the first teeth 22. When the coil 36 of the core part 32 is energized to magnetize the second teeth 38 of the core part 32 to the N pole, the core Part 32
A suction force acts between the second teeth 38 of the rotor 12 and the first teeth 22 of the rotor 12, and the rotor 12
Is further swung by the same angle in the same direction as the previous time until it comes to a position directly facing the second tooth 38.

As a result, the second teeth 38 of the core section 34 are displaced to the right by a quarter pitch with respect to the first teeth 22. When magnetized to the pole, a repulsive force acts between the first teeth 22 and the rotor 12 further swings by the same angle in the same direction as the previous time.

Each of the cores 26, 28, 30, 3
By repeating the power supply control to the rotors 2 and 34, the rotor 12 can be swung together with the secondary mirror 2 by a required angle in a required direction. In the swing structure 10 according to the present embodiment, the rotor 12 is directly fixed to the sub-mirror 2, and a part of the driving means of the sub-mirror 2 is integrated with the sub-mirror 2. As compared with the related art, for example, a single pulse motor is separately provided and the sub-mirror 2 is driven via a coupling mechanism or the like. Therefore, as can be seen from FIG. 1, the swinging structure 10 of the sub mirror 2 can be accommodated within the contour of the sub mirror 2, and does not hinder radio waves incident on the primary mirror (not shown) facing the sub mirror 2. This is effective for increasing the sensitivity of radio telescopes.

In the present embodiment, the first teeth 22 of the rotor 12 are changed to the second teeth of the core by performing energization control for alternately switching the current polarity to the coil 36 of each core. 38 and the first tooth 2 of the rotor 12
The state in which 2 is at the intermediate position of the second teeth 38 of the core portion is alternately repeated, so that the rotor 12 swings. Such a control method of the pulse motor is one of conventionally known control methods, and the present invention is not limited to the control method of the embodiment. For example, by sequentially energizing the coils 36 of each core with the same current polarity, the rotor 12 is rotated in a state where the first teeth 22 of the rotor 12 always face the second teeth 38 of each core. It is also possible to make it swing. Further, in the above-described embodiment, the swing structure in which the mirror constituting the sub-mirror of the radio telescope is a swingable body has been described as an example, but the present invention is not limited to this. For example, the present invention can be applied to an oscillating structure in which a mirror constituting a scanning mirror of a laser scanning device is an oscillating object.

[0017]

As described above, according to the oscillating structure of the present invention, in the core portion where the second tooth is displaced from the position directly facing the first tooth of the rotor, an appropriate current polarity is applied to the coil. , The first tooth of the magnetic rotor moves until it comes to face the second tooth due to, for example, the attractive force of the magnet acting between the rotor and the second tooth. Thus, the rotor swings with the swingable body. That is, on the same principle as the pulse motor, the second tooth
The coils which are shifted with respect to the teeth are sequentially selected, and the coil is energized with an appropriate current polarity, so that the object to be swung can be accurately swung by a desired angle integrally with the rotor. In the swing structure of the present invention, the rotor is directly fixed to the swing body, and a part of the driving means of the swing body is integrated with the swing body. For example, as compared with a case in which a single pulse motor is separately provided and the swingable body is driven via a coupling mechanism or the like, the swinging structure can be made extremely compact.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a swing structure according to the present invention.

FIG. 2 is a sectional side view taken along line AA ′ in FIG.

FIG. 3 is a perspective view showing a rotor constituting the swing structure according to the embodiment.

FIG. 4 is a front view of a rotor.

FIG. 5 is a side view of the rotor.

FIG. 6 is a perspective view showing a stator constituting the swing structure according to the embodiment.

FIG. 7 is a front view of the stator.

FIG. 8 is a side view of the stator.

FIG. 9 is a partial front view showing main parts of a rotor and a stator.

[Explanation of symbols]

 2 Secondary Mirror 4 Mount 6 Steel Ball 8 Mirror Surface 10 Swinging Structure 12 Rotor 14 Stator 16 Outer Surface 18 Permanent Magnet 20 Magnetic Member 22 First Teeth 24 Base 26, 28, 30, 32, 34 Core 36 Coil 38 2 teeth 40 control means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ichifusa Noda 3-10-28 Nishikubo, Musashino-shi, Tokyo F-term in Oshima Prototype Research Laboratory 2H045 AB03 AB22 AB62 5H641 BB17 BB19 GG02 GG04 GG08 GG23 HH03 HH05 HH06 HH08 HH10 5J047 AA00 AB00 BF01

Claims (5)

[Claims] 1. A swingable body, a support body that swingably supports the swingable body, a rotor fixed to the swingable body, a stator fixed to the support body, and provided on the rotor. The stator includes a base fixed to the support, a plurality of cores made of a magnetic material provided on the base, and the plurality of cores. Each of the second teeth is formed by a coil wound around each core portion, and the first teeth are formed in a virtual arc centered on the center of the swing of the swingable body. Are provided at a constant pitch along the circumferential direction of the virtual arc, and the plurality of core portions are erected from the base at intervals in the circumferential direction of the virtual arc; The second tooth is provided at the tip of each core along the circumferential direction of the virtual arc. A plurality of first teeth and a plurality of second teeth of each core portion are provided at the same pitch as one tooth, and are opposed to each other while forming an equal gap in a radial direction of the virtual arc. When the second teeth of one core of the two cores are directly opposed to the first teeth of the rotor, the second teeth of the other core of the two cores are A control unit that is provided so as to be shifted in a circumferential direction of the virtual arc with respect to one tooth, and sequentially selects a core portion in which the second tooth is shifted with respect to the first tooth and energizes the coil. Swinging structure, which is provided. 2. The method according to claim 1, wherein the rotor includes a permanent magnet and a magnetic member that contacts the magnet, and the first teeth are provided on a position of the magnetic member opposite to the magnet. The swing structure according to claim 1, wherein 3. The swing structure according to claim 2, wherein said magnet extends in an arc shape together with said magnetic member. 4. The swing structure according to claim 1, wherein five core portions are provided, and the first teeth of the stator extend in a fan shape. . 5. The oscillating body is a mirror constituting a scanning mirror of a laser scanning device or a sub-mirror of a radio telescope, and the rotor is fixed to a back side of the mirror. Item 3. The swing structure according to Item 1.