JPS6329948Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement of an electromagnetic spring clutch that uses a tightening coil spring for torque transmission.

[Conventional technology]

As this type of electromagnetic spring clutch, for example, an electromagnetic spring clutch developed by the present applicant and described in Japanese Patent Application Laid-Open No. 58-61333 is known.

Referring to FIG. 5 of the accompanying drawings showing a longitudinal side view of this electromagnetic spring clutch, the clutch body A has an output shaft 1, which is a tubular shaft, in the center, and an input shaft on one end of the output shaft. The hub 2 is supported so that it can freely rotate.

The input hub 2 has a boss portion 2A, the outer peripheral surface of which is formed as a tightening surface for the tightening coil spring 3.

On the other hand, an annular member 4 is fitted and fixed to the longitudinal center of the output shaft 1, and the outer diameter of the boss portion 4A of this annular member is the same as or slightly smaller than the outer diameter of the boss portion 2A. It is formed to the same size.

A sleeve 5 is fitted to the input hub 2 and the annular member 4, and the sleeve 5 and the boss portions 2A and 4
An annular gap S is formed between the coil spring 3 and the coil spring 3.

The coil spring 3 has one end 3A formed into an outwardly bent portion that is hooked into a notch 6 formed in the sleeve 5, and the other end 3B is hooked into a notch 7 formed in the annular member 4. be. coil spring 3
is made of a spring wire with a rectangular cross section, and the winding direction is such that the end 3A is held down and the end 3B is the output shaft 1.
The direction in which the diameter expands when turned in the direction of rotation, that is,
This is the direction in which the seaming loosens.

The output shaft 1 has its other end inserted into a center hole 9 of an annular field core 8 so as to be freely rotatable.

The field core 8 is a cylindrical member in which an electromagnetic coil 10 is housed between an inner pole 8A and an outer pole 8B, and a plate-shaped armature 11 is supported on the front surface of the field core 8 so as to be tiltable in the direction of the sleeve 5.

The armature 11 has a large hole 13A in the center through which the spacer 12 fitted on the output shaft 1 is inserted, and small holes 13B in the lower part at symmetrical positions. A protrusion 14 is provided which is cut and formed by processing.

In the armature 11, a hole 13B faces a metal bush 16 fixed with screws 15 at a symmetrical position below the outer pole 8B of the field core 8, and a projection 14 engages with a notch 17 formed in the sleeve 5.

an upper left-right symmetrical portion of the armature 11;
A compression coil spring 19 is interposed between the field core 8 and the front surface of a bobbin 18, and the armature 11 is always pushed and tilted toward the sleeve 5 by the action of the compression coil spring 19.

The armature 11 is excited by applying a voltage to the electromagnetic coil 10 wound around the bobbin 18, and is magnetically attracted to the field core 8 in an upright state.

When the armature 11 stands up, the protrusion 14 disengages from the notch 17 of the sleeve 5 and releases the restraint of the sleeve 5, so that the coil spring 3, which has a winding tendency to tighten around the boss portion 2A of the input hub 2, is integrated with the boss portion 2A. The annular member 4, which rotates and is connected to the coil spring, rotates together with the input hub 2, and torque is transmitted from the input side to the output side.

That is, as long as the sleeve 5 is stopped, the torque transmission is interrupted by the armature 11, but the output rotating member is not free, but is held unrotatable by the armature 11.

[Problem that the invention attempts to solve]

In such a conventional electromagnetic spring clutch, when it is used as a clutch for transmitting torque to a rotary cutter for paper cutting of a copying machine that uses roll paper, the output shaft 1 is connected to the rotary cutter of the copying machine. In order to position or correct the position of the rotary cutter blade while the rotary cutter is connected, the power must be cut off, so the output shaft 1 cannot rotate.In other words, with only the structure shown in FIG. If the power supply is cut off during work such as replacement, the output shaft 1 is restrained in a non-rotating state, so there is a drawback that it is impossible to position or correct the position of the blade of the rotary cutter.

[Means for solving problems]

This invention aims to solve the above-mentioned problems with conventional electromagnetic spring clutches. It is characterized in that it is equipped with a rotating member that is rotatably supported on the outside and has one end in contact with the armature and the other end in contact with an operating member, and the operating member releases the engagement between the armature and the sleeve via the rotating member. There is.

〔Example〕

Next, embodiments of this invention will be described with reference to the drawings.

Fig. 1 is a partially cutaway side view of an example of an electromagnetic spring clutch according to this invention, Fig. 2 is a rear view taken along the line A-A in Fig. 1, and Fig. 3 is a part of Fig. 1. A front view of the right side of the notch, and FIG. 4 is a partial plan view taken along the line B in FIG. 1. In addition, the clutch body
A' is different from the clutch body A of FIG. 5 only in that the notch 17 of the sleeve 5 is made into a protrusion 17', and the armature 11 is provided with an outward protrusion 11A. To explain the characteristic parts, the electromagnetic spring clutch has a flange portion 21A and a boss portion 21B on the torque take-off shaft 20 arranged on the same axis as the output shaft 1.
A cup-shaped operating member 21 having a shape is attached by a key 101 so as to be rotatable integrally with the torque extraction shaft 20 and slidable in the axial direction.

An elastic member such as a compression coil spring 23 is disposed between the spring bearing member 22 which abuts the end of the output shaft 1 and is fixed on the torque extraction shaft 20 and the operating member 21, and is connected to the boss portion 21B. By being held in a loosely fitted state around the operating member 21, the operating member 21 is constantly pushed rearward and the torque extraction shaft 2
It is pressed against a stopper 102 (for example, a snap spring) at the 0 end.

A coil portion 26a of a torsion coil spring 26 is fixed to a support plate 25 screwed to the back surface of the field core 8 by a pin 27 and a retaining member 104, and the torsion coil spring 26 can freely rotate around this pin 27 as a fulcrum. is supported by

An arm 26b that extends from one end of the coil portion 26a of the torsion coil spring 26 and projects toward the operating member 21 side.
The pressing bending portion 2 of the operating member 21 is located at the tip of the operating member 21.
6c is formed, and its arm 26b is connected to the support member 2.
The arm 26 is inserted into a horizontal slit 25b provided in a cut-and-raised part 25a formed by cutting and raising a part of the arm 26.
b serves as a guide slit for rotation.

The other end of the coil portion 26a extends and projects beyond the protruding portion 11A of the armature 11. At the tip of the arm 26d, there is an abutting bent portion 26e for pushing the armature 11 toward the field core 8. Furthermore, a tension coil spring 28 and a compression coil spring 29 are provided between the arm 26d and the support plate 25 and between the base of the protrusion 14 of the armature and the field core 8, respectively.

Note that a cutter connection head 24 is formed at the tip of the torque extraction shaft 20, and this cutter connection head 2
4 is a hole 24A with an open front end and a slit 24B
and a rotary cutter shaft (not shown) is connected with a pin.

In the electromagnetic spring clutch having such a structure, when the operating member 21 is pressed toward the field core 8 side against the repulsive force of the compression coil spring 23, the flange portion 21A of the operating member 21 is bent by the pressing force of the torsion coil spring 26. The bent portion 26c is pushed, thereby causing the torsion coil spring 26 to rotate counterclockwise about the pin 27, and the abutting bent portion 26e formed at the tip of the arm 26d engages the protruding portion 11A of the armature 11. Since the armature 11 is raised by pressing , the engagement between the protrusion 14 of the armature 11 and the protrusion 17' of the sleeve 5 is released, and the torque take-off shaft 20 becomes free.

In this embodiment, the operating member 21 is supported on the torque extraction shaft 20, but it may be supported on the output shaft 1.

[Effect of idea]

As is clear from the above explanation, the electromagnetic spring clutch of this invention can release the restraint of the output shaft at will even when the power is cut off. When used as a clutch for transmitting power, the output shaft can be rotated even when the power is cut off, which has the advantage of facilitating work such as positioning and position correction of rotary cutters, for example.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of an embodiment of the electromagnetic spring clutch according to this invention, Fig. 2 is a rear view taken along the line A-A in Fig. 1, and Fig. 3 is a view similar to Fig. 1. FIG. 4 is a partial plan view taken along line B in FIG. 1, and FIG. 5 is a sectional view of a conventional electromagnetic spring clutch. In the drawings, A...Clutch body, 1...Output shaft, 2...Input hub, 2A...Boss part, 3...Coil spring, 4...Annular member, 4A...Boss part, 5...Sleeve, 8... Field core, 10... Electromagnetic coil, 11... Armature, 14... Protrusion, 1
5... Screw, 20... Torque extraction shaft, 21... Operating member, 22... Spring bearing member, 23... Compression coil spring, 24... Connection head, 25... L
Letter-shaped support plate, 26... Torsion coil spring, 27...
...Pin, 28...Tension coil spring.

Claims (1)

[Scope of utility model registration request] An output shaft, an annular member fitted and fixed onto the output shaft, an input hub fitted onto the output shaft so as to be freely rotatable, and both ends supported by flanges of the annular member and the input hub so as to be freely rotatable. a cylindrical sleeve, an annular gap formed between the inner circumferential surface of the sleeve, the annular member, and the outer circumferential surface of the boss portion of the input hub; a coil spring that is wound around the outer circumferential surface of the boss portion and has one end hooked to the annular member and the other end to the sleeve; and an electromagnetic coil disposed on the rotating shaft with its front face facing the annular member. a built-in field core; and an engaging portion that is loosely fitted onto the rotating shaft between the field core and the annular member, is tiltably supported by the field core, and is engaged with a side surface of the sleeve. In the electromagnetic spring clutch, the electromagnetic spring clutch includes a formed armature and an elastic member that presses the armature toward the sleeve, an operating member movably supported on the output shaft protruding from the back surface of the field core; A rotating member is rotatably supported on the outside of the field core and has one end in contact with the armature and the other end in contact with the operating member, and the operating member connects the armature and the sleeve via the rotating member. An electromagnetic spring clutch characterized by releasing the engagement.