JP2845735B2 - Tension adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a disk made of a hysteresis material on a rotating shaft on which a tension pulley is mounted.
The present invention relates to a tension adjusting device interposed in a magnetic field of a pair of permanent magnets.

[0002]

2. Description of the Related Art A conventional tension adjusting device has a first yoke having a bottomed cylindrical shape, a side surface facing the bottom portion, and is detachably fitted and fixed to an opening of the first yoke. A permanent magnet having a polarity alternately circumferentially fixed to the bottom of the first yoke and the side surface of the second yoke, and a hysteresis is generated in the magnetic field of the pair of permanent magnets. A magnetic coupling having a structure in which a disk made of material is interposed (see Japanese Patent Application Laid-Open No. 52-119747) is mounted, and a rotating shaft on which the disk is mounted and a tension pulley at the tip of the rotating shaft are braked. I have to.

In such a tension adjusting device, when a pair of permanent magnets oppose each other with the same polarity, the magnetization of the disk becomes saturated, and the maximum braking torque is applied to the tension pulley. Further, when the pair of permanent magnets face each other with different poles, the minimum braking torque is applied to the tension pulley.

[0004]

A conventional tension adjusting device
Is thus has granted a constant tension to brake the tension pulley in line material such as yarn and a magnet wire subjected to the tension pulley by the magnetic coupling such, conventional magnetic joint, a bottomed cylindrical shape The second yoke is removably fitted and fixed to the opening of the first yoke.
Due to the magnetic force of the leakage magnetic circuit of the magnet, in the axial direction
The side surface of the second yoke is magnetically attracted to the side surface of the first yoke.
With this structure, the rotational load resistance of the second yoke with respect to the first yoke is increased, and it is difficult to adjust the minute braking torque of the tension pulley.

In the conventional tension adjusting device, the rotary shaft is rotatably supported only on the first yoke side via a bearing. However, the rotary shaft is designed by the first yoke and the second yoke via a bearing. It is common to support them. Such a structure
The second yoke can move axially on the rotating shaft side.
Because it is limited, the side of the first yoke in the axial direction
The structure in which the side surface of the second yoke is magnetically attracted can be omitted.
To reduce the rotational load resistance of the second yoke with respect to the first yoke.
Can be frustrated. However, with such a structure , the first yoke fixed to the main body of the tension adjusting device is rotatable and adjustable , that is, the first yoke is integrated with the first yoke.
When the second yoke is not fixed, the external force in the axial direction
If this occurs, an accident such as damage to the bearing will occur. Therefore, it is necessary to adopt a structure that can prevent such an accident without increasing the rotational load resistance of the second yoke with respect to the first yoke. SUMMARY OF THE INVENTION It is an object of the present invention to provide a tension adjusting device which facilitates adjustment of a braking torque of a tension pulley and can prevent accidental damage to a bearing.

[0006]

In order to achieve the above object, according to the present invention, there is provided a first yoke which is fixed to a main body and to which first permanent magnets having alternating polarities in a circumferential direction are fixed. A second yoke, which is concentrically arranged with the first yoke, is opposed to the first permanent magnet with a predetermined gap therebetween, and has a second permanent magnet formed of the same pole arrangement fixed thereto; A rotating shaft rotatably supported by the first yoke and the second yoke via individually fitted bearings and having a distal end inserted through a through hole formed in the main body; A disc made of a hysteresis material rotatably interposed in the gap, a tension pulley pivotally mounted on the tip of the rotating shaft, and integrally fixed to the first yoke and detachably mounted to the second yoke. Made of freely fixed non-magnetic material And a coupling member, characterized in that the flange portion facing axially end portion and a non-contact state of the coupling member is formed in the second yoke.

[0007]

In the tension adjusting device, since the disk on the rotating shaft is magnetized in the magnetic field of the pair of permanent magnets, the tension pulley axially mounted on the rotating shaft rotates against the magnetizing force of the disk. The braking torque of the tension pulley is adjusted by changing the relative position of the pair of permanent magnets.

[0008]

1 is a front view, FIG. 2 is a side view, and FIG. 3 is a side view in which the upper half of the magnetic coupling of FIG. 1 is sectioned. FIG. 4 is a sectional view taken along line AA of the magnetic coupling of FIG. The tension adjusting devices shown in these drawings are used as a tension adjusting device for a linear material having a relatively small tension value such as a thread or a magnet wire.

Reference numeral 1 denotes a main body of the tension adjusting device, to which a first yoke 3 of a magnetic coupling 2 is fixed by screws (not shown). An annular flange 3a is formed on the outer peripheral surface on the outer surface side, which is the surface on which the first yoke 3 is attached to the main body 1, and on the inner surface side, an annular ring whose polarity is alternately changed in the circumferential direction. The first permanent magnet 4 is fixed. An annular second yoke 5 is disposed concentrically with the first yoke 3, and like the first yoke 3, the second yoke 5 also has a flange portion 5a formed on the outer peripheral surface on the outer surface side. An annular second permanent magnet 6 which is arranged concentrically with the first permanent magnet 4 and has the same pole arrangement is fixed to the side surface.

Concave portions 3b and 5b are formed on the inner surfaces of the inner surfaces of the first yoke 3 and the second yoke 5, respectively, and a pair of bearings 7 in which outer rings are press-fitted into these concave portions 3b and 5b. Accordingly, the first yoke 3 and the second yoke 5 rotatably support the rotating shaft 8. A disk-shaped disk 9 made of a hysteresis material is press-fitted and fixed to the rotating shaft 8.
The first permanent magnet 4 and the second permanent magnet 6 are interposed at a predetermined gap. A pair of collars 10 having one end surface in contact with the disk 9 and the other end surface in contact with the inner ring of the bearing 7 are provided on the rotating shaft 8 between the disk 9 and the bearing 7.
Are fitted. The collar 10 is made of a non-magnetic material (such as a synthetic resin material or an aluminum material). On the other hand, the first yoke 3
A cylindrical coupling member 11 made of a non-magnetic material (synthetic resin material, aluminum material, or the like) fitted so that the end surface abuts on the flange portion 3a is integrally fixed to the outer peripheral surface of the flange member 3a.

A long hole 11a in the circumferential direction is formed on the opposite side of the coupling member 11 from the first yoke 3, and the adjusting screw 12 inserted through the long hole 11a is screwed into the screw of the second yoke 5. The coupling member 11 is detachably fixed to the second yoke 5 by being screwed into the hole 5c. In the magnetic coupling 2 of this embodiment, the end of the coupling member 11 integrally fixed to the first yoke 3 and the second yoke 5 with the collar 10 in contact with the disk 9 and the inner ring end surface of the bearing 7. A small gap S is formed between the flange 5a of the second yoke 5 and the end of the coupling member 11 in a non-contact state.

The tension adjusting device equipped with the magnetic coupling 2 having such a structure is provided with a tension pulley 13 which is screwed to the end of a rotating shaft 8 with a screw, and a wire presser 14 and a guide pulley 15. . Reference numeral 16 denotes an O-ring fitted in the pulley groove of the tension pulley 13, and the O-ring 16 prevents the linear material 17 from slipping.

The tension adjusting device having the above structure is
Since the disk 9 is magnetized in the magnetic field of the first permanent magnet 4 and the second permanent magnet 6, when the tension pulley 13 at the tip of the rotating shaft 8 on which the disk 9 is mounted is rotated,
Since the disk 9 changes its induced polarity while cutting off the magnetic field, the tension pulley 13 has the first permanent magnet 4
And the braking torque is set according to the magnetizing force of the disk 9 by the magnetic field of the second permanent magnet 6. Also tension pulley 1
When changing the braking torque of No. 3, the relative position between the first permanent magnet 4 and the second permanent magnet 6 is adjusted by loosening the adjusting screw 12 and rotating the second yoke 5. After the adjustment, the adjustment screw 12 may be retightened.

[0014]

According to the tension adjusting device of the present invention, the first yoke and the second yoke are connected by the connecting member made of a non-magnetic material, so that the first yoke of the first permanent magnet and the second permanent magnet is connected. When the leakage magnetic circuit bypassing the second yoke is not formed, and the braking torque of the tension pulley is adjusted.
Rotational load resistance of the second yoke Ri of small, thereby facilitating the adjustment of the.

[0015] Further, on the second yoke side to which the connecting member is detachably fixed, a flange portion facing the end surface of the connecting member with a small gap is provided, and the end surface of the connecting member is not in contact with the flange portion. The second yoke rotates with respect to the first yoke
During the adjustment operation in a free state, even if an external force in the axial direction is applied to the second yoke , the second yokes are not damaged before the bearing is damaged.
Abuts against the flange portion coupling member over click, Ru can hold the second yoke main body via a coupling member to these flange portions.
Therefore, the second yoke with respect to the first yoke in the adjustment work is adjusted .
An accident that damages the bearing can be prevented without increasing the rotational load resistance of the yoke.

[Brief description of the drawings]

FIG. 1 is a plan view of a tension adjusting device according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a side view showing a cross section of an upper half of the magnetic coupling of FIG. 1;

FIG. 4 is a sectional view taken along line AA of the magnetic coupling of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Magnetic coupling 3 1st yoke 4 1st permanent magnet 5 2nd yoke 5a Flange part 6 2nd permanent magnet 7 Bearing 8 Rotation shaft 9 Disk 10 Collar 11 Coupling member 12 Adjustment screw

Claims (1)

(57) [Claims] A first yoke fixed to a main body and fixed with first permanent magnets having alternately changed polarities in a circumferential direction; and a first yoke concentrically arranged with the first yoke.
A second yoke to which a second permanent magnet having the same pole arrangement is fixedly disposed facing the permanent magnet with a predetermined gap, and the first yoke via a bearing individually fitted to the inner diameter surface of the yoke; A rotating shaft rotatably supported by the yoke and the second yoke and having a tip inserted through a through hole formed in the main body, and a hysteresis axially mounted on the rotating shaft and rotatably interposed in the gap. A disk made of a material, a tension pulley pivotally attached to the tip of the rotating shaft, and a coupling member made of a non-magnetic material integrally fixed to the first yoke and detachably fixed to the second yoke. A tension adjusting device, wherein a flange portion facing the axial direction in a non-contact state with an end portion of the coupling member is formed on the second yoke.