JP2009195038A - Rotary actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a rotary actuator capable of reducing a moment of inertia, improving a speed of response and providing a low inertia and a high torque even in a short-sized structure with respect to the radius of gyration and an axial length. <P>SOLUTION: The rotary actuator is composed of a stator having a magnet yoke 4, a magnet 5 having four poles on the outer periphery of the yoke and a flange face 41 on one side of the magnet yoke, fitting a bearing 7 at the center of the yoke and fixing a cylindrical-shaped housing 2 on the outer periphery of the flange face. The rotary actuator is further composed of a rotary section configured of a shaft 8 fitted to the bearing, a hub 6 pressed into the shaft, an approximately trapezoidal coil 3 having four segments bonded with the hub and a connection board 10 mounted on the base of the coil. The rotary actuator is further composed of a spiral-shaped FPC board 11 connected from the connection board and capable of rotating the rotary section at a fixed angle and an end cap 9 fixing one side of the FPC board and functioning as a cover. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a rotary actuator that rotates and reciprocates.

  Conventional galvanometers (also called galvanometers) that indicate the amount to be measured by rotating the arc in response to the current flowing through the moving coil are rectangular coils, etc., and the bearings are mounted with pivot bearings. A helical spring is used to return to a fixed position when the movable coil is disconnected, and the needle is moved according to the magnitude of the excitation current, so that a relatively weak torque is sufficient.

  There has been a proposal that employs a rotary actuator as an application technology of such a galvanometer.

Referring to Patent Document 1 as a conventional example, the magnetic gap between the armature and the field is set inside the armature magnetic pole with respect to a wide relative angle change between the armature and the field of the rotary actuator for rotation angle control. Form a concave notch on the opposite side of the field at the center of the armature magnetic pole or reduce the axial thickness at the center of the armature magnetic pole. The configuration in which the amount of change in the magnetic flux with respect to the minute rotation angle acting between the armature and the field is kept substantially constant, and the torque is prevented from decreasing as the rotor rotates. Has been.

  Therefore, even if the rotor that rotates within a predetermined angle with respect to the stator is stopped at a plurality of positions, torque reduction does not occur in the wide rotation range of the rotor, so that the stable range is achieved. Although it is said that a stopped state can be obtained, the processing or assembly processing for forming and configuring the magnetic gap requires man-hours.

Further, referring to Patent Document 2, the stator is wound around the stator iron core having salient poles, in order to eliminate the occurrence of reversal torque in the non-energized torque. The rotor is rotatably arranged on the outer peripheral side of the stator, and is configured by attaching a two-pole permanent magnet to a cylindrical yoke.
This permanent magnet has a single-walled semicircular arc plate shape, but the permanent magnet facing surface (inner diameter side) and opposite surface (outer diameter side) of each unit magnet have different radii. The thickness of both end portions which are magnetic pole boundary portions is set to be 0.75 times the thickness of the central portion.

  Therefore, the relationship between the stator yoke and the rotor is different between Patent Document 1 and Patent Document 2, but the same is true when the magnetic gap amount is displaced with the rotation angle.

  Further, referring to Patent Document 3, in order to make the torque characteristics uniform, the shape of the salient pole of the rotor wound with the coil is the length between the surface of the salient pole facing the stator and the center of the rotation axis. , The salient poles are formed on the rotor core so as to change depending on the angle from the center, the arc outer shape is formed from different radii, and the permanent magnet on the opposing surface is the same as described in Patent Document 2, The arc centers of the opposing surface arc (inner diameter side) and the opposite surface arc (outer diameter side) are formed so as to be shifted so that the thickness of the magnetic pole boundary portion is slightly thinner than the thickness of the magnetic pole center portion.

The techniques described in each of these patent documents are characterized in that either the stator or the rotor, or both the stator and the rotor are formed into a unique shape for torque improvement, and require special processing. It was a thing.
JP-A 63-249456 Japanese Patent Laid-Open No. 9-163708 JP 2004-312829 A

The so-called galvanometer used in galvanometers, which were conventional current measurement instruments, amplifies the deflection of the pointer by attaching a mirror and projecting reflected light instead of the pointer to detect minute currents. I was trying to point to the numbers.
A galvanometer scanner is a successor to this mechanism.
The galvanometer scanner, which is the current optical scanner product, has to scan or position a heavy mirror attached to a rotating shaft at high speed and with high accuracy, and therefore, a galvanometer scanner that can be used for a heavy load is required. It was.
Furthermore, there has been a demand for a small moment of inertia for high-speed response and high-speed operation.

In addition, a coreless motor with fast response has been used for steering power of a light aircraft. However, in a usage in which forward / reverse rotation is always forced, a brushless coreless motor has a short life.
Further, the rotary solenoid has drawbacks such as slow response speed and inability to control the angle.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotary actuator that improves torque, greatly improves the life, decreases the moment of inertia, and improves the response speed.

  In order to solve the above problem, a rotary actuator according to claim 1 of the present invention has a magnet yoke, a four-pole magnet on the outer periphery of the yoke, and a flange surface on one side of the magnet yoke. A stator with a bearing attached to the center of the shaft, a cylindrical housing fixed to the outer periphery of the flange surface, a shaft mating with the bearing, a hub press-fitted into the shaft, and a four-segment substantially trapezoidal coil bonded to the hub A rotating part composed of a connection plate attached to the bottom surface of the coil, a spiral FPC board connected from the connection board and capable of rotating the rotation part by a predetermined angle, and an end cap for fixing one side of the FPC board and covering It is characterized by comprising.

  The rotary actuator according to claim 2 of the present invention is characterized in that, in claim 1, the circumferential surfaces of the substantially trapezoidal coils are arranged such that adjacent coils overlap each other.

  Furthermore, the rotary actuator according to claim 3 of the present invention is characterized in that, in claim 1 or claim 2, the movable part of the FPC is rotatable in a U-shape.

  In the rotary actuator of the present invention, torque can be improved by using a four-segment coil, and by using an FPC, a non-contact structure can be obtained, and the life can be greatly improved. The response speed could be improved by placing the part that does not contribute to the center part with a small radius of rotation and a small turning radius.

  Embodiments of the present invention will be described below with reference to the drawings.

  1-5 is a figure regarding the rotary actuator 1 of this invention. As shown in FIG. 1, the rotary actuator 1 is accommodated in the stator housing 2 with the rotor coil 3 disposed so as to surround the outside of the magnet 5. The stator housing 2 is formed in a cylindrical shape, and a flange portion 41 formed on the magnet yoke 4 is attached to one of the axial directions, and an end cap 9 is attached to the other. The magnet yoke 4 is provided with a sleeve-shaped bearing 7 that rotatably supports the shaft 8.

  As shown in FIG. 3, the magnet yoke 4 has a structure in which four pole magnets 5a to 5d, in which N poles and S poles are alternately arranged, are fixed to four surfaces as members for generating a field magnetic flux on the outer periphery thereof. It is said that.

As shown in FIGS. 1 and 2, the rotor coil 3 has a hollow internal coil body formed by winding a predetermined number of turns of a coil, which is a conductor, in a substantially trapezoidal shape (or arcuate shape) on the peripheral side surface of the magnet 5. A predetermined number of turns of a coil, which is a conductor, are wound in a substantially trapezoidal shape (or arcuate shape) on the inner coil 3a arranged in parallel and the peripheral side surface of the ascending shape using the inner coil 3a as a virtual disk. A hollow external coil body is formed of an external coil 3b arranged in parallel covering the internal coil 3a.
In other words, the circumferential surface of the substantially trapezoidal coil is arranged in a cross pattern so that adjacent coils overlap each other.

  The cross-shaped four-segment rotor coil 3 (3a, 3b) is bonded to the hub 6 press-fitted into the shaft 8.

A connection plate 10 for supplying power to the rotor coil 3 attached to the hub 6 is provided, and power supply to the connection plate 10 is performed by the FPC board 11.
Since both the rotor coil 3 and the connection plate 10 rotate at a predetermined angle, the FPC board 11 is attached in a spiral shape, thereby adjusting the speed at which the hairspring is expanded and contracted in the same manner as a flywheel of a watch, and the FPC board 11 The other is fixed to an end cap 9 for closing the opening of the stator housing 2.

Reference numeral 12 denotes a lead wire for controlling power supply to the rotor coil 3 (3a, 3b) from an external control circuit on the FPC board 11.
Reference numeral 13 denotes a retaining ring for preventing the shaft 8 from moving (missing) in the axial direction.

  6 and 7 are diagrams relating to a stopper structure adopted for controlling the rotation angle in the rotary actuator of the present invention.

  A connecting portion 102 of the connection board 10 is provided, and an FPC board 11 formed with one side fixed to the lid member 14 and the other is formed in a spiral shape is inserted and fixed in a slit 103 for winding and fixing to the mounting portion 102. .

  Further, the bundling plate 10 is provided with stoppers 101 on both disk-shaped wings, and the coil rotor 3 is driven by the stopper 101 and the stopper jetty 141 when being fed and rotated by the stopper jetty 141 formed on the lid member 14. It becomes possible to rotate and rotate within an angle set in the region.

  In another embodiment, the stator housing 2 formed in a cylindrical shape has a cover member 14 attached to one side in the axial direction and a flange portion 41 formed on the bearing holder 42 attached to the other side. Are provided with bearings 71 and 71 for rotatably supporting the shaft 8, and four pole magnets 5a to 5d in which N poles and S poles are alternately arranged as members for generating a field magnetic flux on the outer periphery thereof. Is constituted by the magnet yoke 4 fixed to the four surfaces, the diameter of the rotor coil can be reduced, and further, the low inertia can be improved.

  The galvanometer scanner, which is an optical scanner product that scans and positions the mirror attached to the rotating shaft at high speed and with high accuracy, requires a small rotor inertia in order to operate high-speed operation at high frequency. However, in the rotary actuator of the present invention, the portion that does not contribute to the torque generation of the coil is arranged in the central portion with a small rotation radius and a small moment of inertia. As a result, the response speed can be improved and the axial direction can be shortened, so it can also be downsized, making it ideal for use in products that require low inertia and high torque, such as galvanometer scanners. It can be.

It is the plane sectional view showing the internal structure of the rotary actuator concerning Example 1 of the present invention. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. FIG. 2 is a side view with the “end cap 9” of FIG. 1 removed. It is the fragmentary sectional view which showed the internal structure of the rotary actuator which concerns on Example 1 of this invention. It is the plane sectional view showing the internal structure of the rotary actuator concerning Example 2 of the present invention. It is the side view which removed the "end cap 9" of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary actuator 2 Housing 3 Coil 4 Magnet yoke 5 Magnet 6 Hub 7 Bearing 8 Shaft 9 End cap 10 Connection board 11 FPC board 12 Lead wire 13 Retaining ring 14 Cover member 41 Flange part 42 Bearing holder 71 Bearing

Claims (3)

A magnet yoke, a four-pole magnet on the outer periphery of the yoke, a flange surface on one side of the magnet yoke, a bearing attached to the center of the yoke, and a cylindrical housing fixed to the outer periphery of the flange surface; A shaft coupled to the bearing, a hub press-fitted into the shaft, a four-segment substantially trapezoidal coil bonded to the hub, and a rotating part composed of a connection plate attached to the bottom surface of the coil, and connected from the connection plate A rotary actuator comprising a spiral FPC board whose rotating part can rotate by a predetermined angle, and an end cap that fixes and covers one side of the FPC board.
The rotary actuator according to claim 1, wherein the circumferential surfaces of the substantially trapezoidal coils are arranged such that adjacent coils overlap each other.
The rotary actuator according to claim 1 or 2, wherein the movable part of the FPC is rotatable in a U-shape.

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