JP2709844B2 - Magnetic coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an air gap type in which a driving torque or a braking torque is obtained by a magnetoresistive force generated by a magnetic force flowing through an air gap between a driving side and a driven side. It relates to a magnetic coupling.

[Conventional technology]

The magnetic coupling flows through a friction type magnetic coupling that obtains a driving torque or a braking torque by a frictional force generated by connecting a driving side and a driven side with a magnetic force, and an air gap between the driving side and the driven side. Air gap type magnetic joints, which obtain driving torque or braking torque by magnetic resistance generated by magnetic force, i.e., induction force, are roughly classified into air gap type magnetic joints. It is used for various applications because of its easy control of torque.

Various types of devices for controlling the torque in this type of air gap type magnetic coupling have been developed depending on the device in which the magnetic coupling is incorporated.For example, a device for controlling the amount of magnetic flux generated from an electromagnet into electric droplets, A device that controls the magnetic resistance value in a magnetic circuit by adjusting the air gap between the magnet and the magnetic disk, or between a magnet and a magnetic shielding plate made of a magnetic material provided between the magnet and the magnetic disk. Various types have been known, such as those that control the amount of magnetic flux diverted to the magnetic disk by forming a short-circuit path for the magnetic flux.

However, among them, the torque control device that controls the amount of magnetic flux of the electromagnet needs to provide another electric circuit between the electromagnet and the power supply for connection, and has a problem that it is relatively expensive. Also, a torque control device that controls the amount of magnetic resistance in the magnetic circuit by adjusting the size of the air gap,
For example, as in a magnet tension device disclosed in JP-A-59-182167, a magnetic brake for a fishing reel disclosed in U.S. Pat. In order to adjust the tension through the cam mechanism as a load, or to adjust by manually rotating the screw member,
Either the magnet or the magnetic disk must be configured to be movable in the axial direction, and the structure of the apparatus itself is complicated, and there is a problem that it cannot be provided at low cost.

Therefore, a magnetic shield plate type, which has a simple structure, can be provided at low cost, and can easily control the torque, is preferred as the air gap type magnetic coupling capable of controlling the torque. A hysteresis clutch / brake disclosed in Japanese Patent Application Laid-Open No. 54-4017 is known. The magnetic coupling includes a permanent magnet fixed to a yoke and having alternately changed magnetism in a circumferential direction, and a magnetic disk (semi-hard magnet) opposed to the permanent magnet via an air gap. The magnetic shield plate is inserted from the outside in the radial direction so as to be freely inserted and removed. The torque is controlled by adjusting the insertion amount of the magnetic shield plate to control the amount of magnetic flux detour. In this magnetic joint, the torque can be controlled from almost zero to a maximum value by symmetrically providing a pair of magnetic shield plates having a substantially semicircular shape.

Further, as this kind of magnetic shield plate type air gap type magnetic coupling, for example, a magnetic clutch device disclosed in Japanese Patent Application Laid-Open No. 54-81447 is known in addition to the above.
In this magnetic joint, a magnetic shield plate is provided between the permanent magnet and the magnetic disk, and the position of the slit formed in this magnetic shield plate is changed with respect to the permanent magnet divided in the circumferential direction and alternately arranged N and S. Thus, the amount of detour of the magnetic flux to the magnetic disk side is adjusted.

[Problems to be solved by the invention]

However, such a magnetic shielding plate type air gap type magnetic joint still has the following problems.

First, in the magnetic coupling disclosed in Japanese Patent Publication No. 54-4017, it is necessary to pivot the magnetic shielding plate radially outside of the magnetic coupling main body. If it is narrow, it will not be possible to mount the magnetic joint and it will not only be versatile, but also because the air gap between the permanent magnet and the magnetic disk is very small,
When mounting this magnetic coupling on a winding machine or reel, it is difficult to mount the magnetic shield, such as adjusting the gap to incorporate the magnetic shield plate into the permanent magnet and the magnetic disk in a non-contact state. There is a problem.

Next, in the magnetic coupling disclosed in Japanese Patent Application Laid-Open No. 54-81447, the magnetic shielding plate is magnetically attracted to the permanent magnet in a state of being fitted and centered in a cylindrical sleeve. When installing on a tensioning device for wire material,
There has been a problem that the magnetic shielding plate cannot be rotated by using the tension acting on the wire as a load.

The present invention has been made to solve such a problem, and has a simple structure, can be provided at a low cost, can perform stable torque control with a light load, is easily mounted on a device, and is a versatile air gap. It is intended to provide a magnetic coupling.

[Means for solving the problem]

In order to respond to such a demand, the magnetic coupling according to the present invention includes an annular magnet fixed to the yoke and formed so that different magnetic poles face alternately in the circumferential direction of the side surface, and a center hole of the magnet and the magnet. A rotating shaft rotatably inserted into the center hole of the yoke and supported by the yoke via a bearing, and a magnetic disk axially mounted on the rotating shaft and facing the side surface of the magnet at a predetermined interval in the axial direction. A disk portion interposed between these magnets and the magnetic disk, and a cylindrical portion fitted to the yoke via a bearing, and the strength of the magnetic field according to the relative rotation position with respect to the magnets. A magnetic shielding plate capable of changing the diameter is provided, and an air gap in the axial direction is formed between the disk portion and the magnet, and between the disk portion and the magnetic disk, and provided on the disk portion. Multiple radially extending slits An air gap is formed into, is made larger than the air gap the air gap to the circumferential direction to the axial direction.

[Action]

According to the present invention, the magnetic flux of the magnet bypasses the magnetic disk through the fan-shaped portion between the slits in the disk portion of the magnetic shielding plate, and the magnet and the magnetic disk are connected by the magnetoresistive force generated by the magnetic force. You. Also, in this state, when the relative position in the rotation direction between the magnet and the slit forming position in the disk portion of the magnetic shielding plate changes, a short circuit circuit of magnetic flux is generated between the magnet and the disk portion of the magnetic shielding plate. As a result, the amount of magnetic flux diverted to the magnetic disk is reduced, and the magnetic resistance obtained by the magnetic force is reduced.

〔Example〕

1 to 3 show an embodiment in which a magnetic coupling according to the present invention is applied to a tension control device for a wire, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a front view of a magnetic shielding plate, and FIG. FIG. 3 is a schematic front view of a tension control device for a filament material embodying the present invention. In the present embodiment, a tension control device incorporating the magnetic coupling of the present invention is provided in a winding machine that winds a magnet coil as a wire material, and the magnet is directed to a winding unit of the winding machine. In the traveling route of coil 1 (hereinafter referred to as line 1),
A tension control device indicated by reference numeral 2 as a whole is provided. Fixed housing 3 as a device main body of the tension control device 2
, A mounting plate 5 of the magnetic coupling 4 is fixed, and a dish-shaped yoke 6 is fixed to a vertical surface thereof by a set screw 7. A case 8 formed in a semi-cylindrical shape with a bottom and opening upward is fixed to the outer peripheral portion of the yoke 6 with a plurality of set screws 9, and further fitted on the inner peripheral surface of the yoke 6. A cylindrical portion 11a of a magnetic shielding plate 11, which will be described later, is rotatably supported on the rolling bearing 10. A rotating shaft 12 is rotatably supported by the cylindrical portion 11a and the vertical plate 8a of the case 8 via rolling bearings 13, 13, and 14. The projecting portion of the rotating shaft 12 from the housing 3 is The tension pulley 15 is fixed with a key and a bolt. In FIG. 3, reference numeral 16 denotes a tension arm swingably supported by a shaft support 17 on the housing 3 side.
The auxiliary tension pulley 18 is rotatably pivoted,
The wire 1 is guided from the snail guide 19 to the tension pulley 15 and is in contact with the tension pulley 15 for about 360 °. Has been taken. An adjusting spring 2 is provided between the other free end of the tension arm 16 and a spring hole 11c (see FIGS. 1 and 2) of a projecting piece provided on the disk portion 11b of the magnetic shielding plate 11.
An adjustment spring 21 is also stretched in series with the adjustment spring 20 between the spring hole 11c of the magnetic shielding plate 11 and the casing 3 side. In this way, the tension arm 16 and the magnetic shield plate 11 connected by the adjustment spring 20 so as to rotate in conjunction with each other are provided with a turning force in the direction of applying tension to the wire 1 by the adjustment springs 20 and 21. ing.

The magnetic coupling 4 includes an annular permanent magnet 22 fixed to the end face of the yoke 6. In the case of the present embodiment, the permanent magnet 22 has a side surface divided into four parts in the circumferential direction, and has an N pole and an S pole. The magnetic poles different from the poles are formed so as to face alternately. A boss 23 is press-fitted into the knurled portion 12a of the rotating shaft 12, and is fixed by plastic deformation.The boss 23 is formed in a disc shape with a material having a large magnetic hysteresis such as a permanent magnet material. Magnetic disk 24 is fixed. A disk portion 11b of the magnetic shielding plate 11 is provided between the magnetic disk 24 and the permanent magnet 22.
An air gap indicated by reference numeral g in the figure is formed between the permanent magnet 22 and the permanent magnet 22. Also,
The magnetic shielding plate 11 is integrally formed of a cylindrical portion 11a and a disk portion 11b by a magnetic material, and a predetermined air gap indicated by a symbol G in the figure is circularly arranged at circumferentially equal positions of the disk portion 11b. A plurality of slits 11d (four in accordance with the number of magnetic poles of the magnet 22) are formed as magnetically disconnected portions extending in the radial direction so as to be formed in the circumferential direction. The air gap G of the slit 11d is formed to be larger than the air gap g between the magnetic disk 24 and the magnetic shielding plate 11.

With this configuration, the magnetic flux passing through the magnetic shield plate 11 from the N pole of the permanent magnet 22 in the state shown in FIG. Since the air gap g is larger than the air gap g between the magnetic disks 24, the magnetic flux circuit is formed on the magnetic disk 24, the magnetic shielding plate 11, the S pole of the permanent magnet 22, and the yoke 6. The rotating shaft 12 is braked by the resistance force via the magnetic disk 24. When the magnetic shield plate 11 is rotated from the state shown in FIG. 2 to 45 °, the displacement of the relative rotation position between the magnetic pole on the magnet 22 and the slit 11d causes the magnetic flux to the magnetic disk 24 side. The amount of detour is small.

The operation of the tension control device configured as described above will be described. A tension is applied to the wire 1 attached to the tension pulleys 15 and 18 from the snail guide 19 and guided to the winding section by the auxiliary tension pulley 18 at the tip of the tension arm 16 which is rotated by the spring force of the adjustment springs 20 and 21. Have been. The magnetic flux of the permanent magnet 22 forms a circuit along the path, and the rotating shaft 12 is braked via the magnetic disk 24 by this magnetoresistive force. , The maximum braking torque value is initially set.

If an abnormal tension acts on the wire 1 for any reason during the winding operation of the wire 1 in such a state, the tension arm 16 is rotated by this tension, and the magnetic shield plate 11 connected to the tension arm 16 by the braking spring 20 is moved. Since the magnetic disk 24 rotates, the amount of magnetic flux that bypasses the magnetic shielding plate 11 to the magnetic disk 24 by the amount of the rotated displacement decreases, and the braking torque decreases. Further, when the magnetic shielding plate 11 rotates and its slit 11d is displaced by 45 ° from the position in FIG. 2,
Since the magnetic flux circuit has a short-circuit path that does not constitute the magnetic disk 24, the braking torque is zero. As described above, the braking torque of the magnetic joint 4 becomes smaller as the position of the slit 11d as the magnetically disconnected portion of the magnetic shielding plate 11 changes, so that the tension applied to the line 1 when the abnormal tension occurs in the line 1 Is reduced, and disconnection due to tension can be prevented beforehand. When the abnormal tension is eliminated, the tension arm 16 returns to the initial setting state, and the wire 1 shifts to winding with a predetermined tension applied. The amount of return of the tension arm 16 by the braking force of the magnetic joint 4 can be adjusted by changing the distance between the shaft support 17 of the tension arm 16 and the auxiliary tension pulley 18.

FIG. 4 is a longitudinal sectional view of a braking device showing another embodiment of the present invention corresponding to FIG. In the braking device 4A of the present embodiment, a magnetic shielding plate 11A formed into a bottomed cylindrical shape is provided on the outer peripheral surface of a yoke 6A fixed to the mounting plate 5 with a set screw 7.
It is rotatably fitted via a rolling bearing 10. Also, the case 8 provided in the embodiment of FIG. 1 is not provided. Other configurations are almost the same as those of the above-described embodiment, and perform the same operation as that of the above-described embodiment.

In each of the above embodiments, the permanent magnet 22 is set to NS, NS.
Although the example of dividing into four is shown, this may be two poles of NS, and the slit 11d of the magnetic shielding plate 11 corresponding to this may be two. Also, slit the magnetically disconnected part of the magnetic shield plate 11.
Instead of being constituted by 11d, a nonmagnetic material may be filled in the slit 11d to bypass the magnetic flux of the permanent magnet 22 to improve the demagnetization efficiency. Further, in each of the above embodiments, the example in which the entire magnetic shielding plate 11 is formed of a magnetic material has been described.
If only 11b is made of a magnetic material and the cylindrical portion 11a is made of a non-magnetic material, leakage of magnetic flux to the bearing 10 can be prevented. Also, the magnet need not be the permanent magnet 22, for example, Jikken 48-18935.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, an electromagnet in which an electromagnetic coil is wound around an iron core provided on the yoke 6 side, and a magnetic disk 24
May be formed of a magnetic material such as carbon steel for machine structural use.
Furthermore, in the above description, an example was shown in which the magnetic coupling was incorporated in the control device of the winding machine. However, the magnetic coupling can also be used for a braking device of a fishing reel, for example, Is not limited. Further, the present apparatus controls the torque based on the relative positional relationship between the magnet and the magnetic shielding plate. The magnet may be rotatable and the magnetic shielding plate may be fixed.

〔The invention's effect〕

According to the magnetic coupling according to the present invention as described above,
An annular magnet fixed to the yoke and formed such that different magnetic poles alternately face in the circumferential direction of the side surface portion, and rotatably inserted into the center hole of the magnet and the center hole of the yoke and supported by the yoke via a bearing. A rotating shaft, a magnetic disk axially mounted on the rotating shaft and facing a magnet side surface at a predetermined interval in the axial direction, and a disk portion interposed therebetween and the yoke fitted via a bearing. A magnetic shield plate having a cylindrical portion and a magnetic field that can vary the strength of the magnetic field in accordance with the relative rotation position with respect to the magnet, between the disk portion and the magnet, and between the disk portion and the magnet. An air gap in the axial direction is formed between the disk and the disk, and a plurality of slits provided in the radial direction of the disk portion form an air gap in the circumferential direction. Formed larger than the air gap in the axial direction. In, an excellent effect described below.

That is, according to the present invention, the magnetic flux from the magnet is bypassed to the magnetic disk by the relative rotation position between each magnetic pole of the magnet and the slit portion in the disk portion of the magnetic shielding plate,
It is possible not to make a detour, so that the magnet and the magnetic disk can be connected by a magnetoresistive force generated by a magnetic force, or the magnetoresistive force can be reduced or made substantially zero.

Therefore, according to the present invention, the magnetic shield plate can be easily rotated and displaced relative to the magnet by a light load such as the tension of the linear material, and stable torque control can be performed. In addition, since the magnetic shielding plate is supported on the yoke via the bearing, mounting on the device is facilitated, and versatility is improved.

[Brief description of the drawings]

1 to 4 show an embodiment of a magnetic coupling according to the present invention, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a front view of a magnetic shield plate, and FIG. 3 is a line embodying the present invention. FIG. 4 is a longitudinal sectional view of a magnetic joint showing another embodiment of the present invention corresponding to FIG. 4,4A ... magnetic coupling, 10 ... bearing, 11,11A ... magnetic shielding plate, 11a ... cylindrical part, 11b ... disk part, 11d ... slit, 12 ... rotary shaft, 22 ... permanent Magnet, 24 ... Magnetic disk.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeharu Arai 2-678, Aioi-cho, Kiryu-shi, Gunma Prefecture Inside the Ogura Kurachi Co., Ltd. Co., Ltd. (56) References JP-A-54-81447 (JP, A)

Claims (1)

(57) [Claims] An annular magnet fixed to a yoke and formed so that different magnetic poles alternately face each other in a circumferential direction of a side surface portion; and a rotatably inserted through a center hole of the magnet and a center hole of the yoke. A rotating shaft supported on the yoke via a bearing, a magnetic disk axially mounted on the rotating shaft and facing a side surface of the magnet at a predetermined interval in the axial direction, and between the magnet and the magnetic disk A magnetic shielding plate having an interposed disk portion and a cylindrical portion fitted to the yoke via a bearing, the magnetic shielding plate being capable of varying the strength of a magnetic field in accordance with a relative rotation position with respect to the magnet; An air gap is formed in the axial direction between the disk of the magnetic shielding plate and the magnet, and between the disk portion and the magnetic disk, and a radial direction provided on the disk portion is provided. The magnetic ring of the magnet ring is The same number of forming an air gap in the circumferential direction, the magnetic coupling, characterized in that the air gap to the circumferential direction is formed to be larger than the air gap to the axial direction.