JPS633466Y2 - - Google Patents

Description

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

A conventional electromagnetic spring clutch is shown in FIG. 1 in a longitudinal cross-sectional side view.

A conventional electromagnetic spring clutch A shown in FIG. 1 has an output hub 1 as an output rotating member connected to an input shaft of a driven device so as to rotate together with the input shaft.

Input hub 2 as an input rotating member is output hub 1
A groove pulley 4 for connecting to an external drive source is fixedly attached with the same axis line.

On the other hand, a boss portion 7 is formed on the output hub 1 at a position adjacent to the boss portion 2A of the input hub 2.

The outer diameter of the boss portion 7 of the output hub 1 is the same as or slightly smaller than the outer diameter of the boss portion 2A of the input hub 2.

The boss portion 7 concentrically has a sleeve 8 having an inner diameter that forms an annular gap S of a predetermined width between the boss portion 7 and the outer circumferential surface 7a.
Moreover, it is supported so that it can freely rotate.

The sleeve 8 has one end fitted to the boss 7 so that the end faces are aligned, and the other end is concentrically supported on the input hub 2 so as to be freely rotatable.

A coil spring 3 for seaming is housed in the gap S.

The coil spring 3 is a spring wire product with a rectangular cross section, and has one end 3A inserted into a notch 9 formed in the sleeve 8, and the other end 3B inserted into a boss 7.
They are respectively hooked in notches 10 formed in the boss portion 2A, and have a winding tendency at least to the outer circumferential surface 2a of the boss portion 2A, so that the end portion 3B outputs the winding direction with the end portion 3A being held down. When turned in the direction of rotation of the shaft 1, the diameter expands, that is, the direction in which the seaming loosens.

On the other end of the output hub 1, a field core 6, which becomes a fixed member when attached to a device, is supported concentrically so as to be rotatable relative to the output hub 1.

The field core 6 fixed to the mounting plate 5 is a member in which an inner pole member 6A and an outer pole member 6B are integrally joined.The inner pole member 6A consists of a flange part and a boss part, and the outer pole member 6B has a It is a member formed by pressing a single metal plate into a shape having a vertical wall portion, and the boss portion of the inner pole member 6A is fitted and fixed to the vertical wall portion. Note that the end faces 6a and 6b of the inner pole member 6A and the outer pole member 6B face the same vertical plane.

Further, a bobbin 17 around which an electromagnetic coil 16 is wound is fitted and fixed to the boss portion of the inner pole member 6A.
The base end portions of compression coil springs 18, 18 (only one is shown) are housed in symmetrical positions on the upper front surface of the bobbin 17, respectively.

The compression coil spring has its lower end supported at the lower part of the field core 6 which is a fixed member, and contacts near the upper end which is the free end of the armature 13 which is freely tiltable in the axial direction. Gives a tendency to tilt in a direction.

The armature 13 is a plate-like object formed by pressing a single metal plate, and has a protrusion 13 cut out and formed by pressing at the left and right center position of the upper end.
A is provided.

The projection 13A can freely fit into the recess 12 formed in the sleeve 8 by tilting the armature 13 toward the sleeve.

The recess 12 may have a radial slit shape, but in order to easily and reliably fit the protrusion 13A into the recess 12, the recess 12 is formed on the side that approaches the protrusion 13A when the sleeve 8 is rotating. one side,
It is inclined so as to gradually reach the bottom surface of the recess 12.

The armature 13 is provided with a large hole 13B.

A collar-shaped spacer 11 that maintains the distance between the boss portion 7 and the field core 6 is inserted through the hole 13B, and when the armature 13 is magnetically attracted to the field core 6 and tilted by being pushed by the compression coil spring 18. The dimensions are determined so as not to interfere with the spacer 11.

The armature support structure for the field core 6, which is a fixed member, consists of metal bushes 14, 14 (only one shown) fixed to the field core 6 by screws 15, 15 (only one shown), and a predetermined position at the bottom of the armature 13. It has a structure in which the holes 13B' and 13B' (only one of which is shown) are loosely fitted.

Note that the bushes 14, 14 (only one is shown) may be made of rubber.

Electromagnetic spring clutch A with the above structure
By applying a voltage to the electromagnetic coil 16, a magnetic flux passes through the inner pole member 6A and outer pole member 6B of the field core 6 and the armature 13, and the excited armature 13 is elastically pushed by the compression coil spring 18. The protrusion 13A of the armature 13 is magnetically attracted to the field core 6 against pressure, and the protrusion 13A of the armature 13 is attached to the sleeve 8.
escapes from the recess 12.

In this state, the force that binds the sleeve 8 is removed, so the sleeve 8 can rotate freely, and the coil spring 3, which has a winding tendency to tighten around the boss 2A of the input hub 2, connects with the boss 2A. The boss portion 7, which rotates together with the input hub 2 and is connected to the coil spring 3, rotates together with the input hub 2, and torque is transmitted from the input side to the output side.

Next, when the voltage application to the electromagnetic coil 16 is stopped, the magnetic flux disappears and the force that attracts the armature 13 to the field core 6 is removed.
3, the sleeve instantly tilts in the direction of 8.

Armature 13 tilted in 8 directions of sleeve
In this case, the protrusion 13A connects to the recess 1 within one rotation of the sleeve 8.
2 and forcibly stops the sleeve 8.

When the sleeve 8 stops, the notch 9 of the sleeve 8
Coil spring 3 with end 3A hooked to
Due to the inertia of the boss part 7 side that hooks the end part 3B, the end part 3B moves in the direction of continuing the previous rotation.
is rotated and the diameter is expanded.

This allows the input hub 2 of the coil spring 3 to
At the same time that the tightening force on the coil disappears and the torque transmission is interrupted, the boss portion 7 connected to the sleeve 8 via the coil spring 3, that is, the output hub 1, is forcibly stopped by the armature 13. It receives the embrace of the sleeve 8 that is being held and immediately stops.

The coil spring 3, whose diameter has expanded instantaneously, will once again come into sliding contact with the inner diameter surface of the boss portion 2A of the input hub 2 due to its own diameter reduction force, but as long as the sleeve 8 is stopped by the armature 13,
The output hub 1 never rotates.

As described above, although the electromagnetic spring clutch A shown in FIG. 1 operates, the structure is such that the protrusion provided on the armature is recessed into the recess of the sleeve when the torque transmission is interrupted.
Stopping from high-speed rotation also requires protrusions and notches that will not cause operational errors, which can be difficult in terms of design.

Based on the above-mentioned points of view, this invention provides an electromagnetic spring clutch that can reliably stop the sleeve and eliminates the risk of operation errors. an annular gap S between an output hub having a boss portion disposed adjacent to the hub portion and the boss portion and the outer circumferential surface;
a sleeve which forms a sleeve and is arranged concentrically with the input hub and the output hub so that it can freely rotate;
Further, the other end is hooked to the boss part of the output hub, and the coil spring has a winding habit at least to the boss part of the input hub, and is fixed to the end face of the sleeve. A friction member, an armature that can freely make frictional contact with the friction member and is oriented perpendicular to the axis of the sleeve, a field core that supports the armature movably only in the axial direction, and presses the armature in the direction of the sleeve. The clutch-off state is maintained by restraining the sleeve by bringing the armature, which is supported movably only in the axial direction by the field core, into frictional contact with the friction member attached to the sleeve. be.

Next, the electromagnetic spring clutch of this invention will be explained by way of examples with reference to the drawings.

FIG. 2 shows an embodiment of the electromagnetic spring clutch of this invention in a longitudinal sectional side view. The only difference is the structure of the sleeve, the structure of the armature, and the support form; other parts are the same as the conventional electromagnetic spring clutch shown in Fig. 1, so similar members are given the same reference numerals. explain.

As an input rotating member, an input hub 2 that rotates together with the groove pulley 4, and a boss portion 2A of this input hub 2
an output hub 1 having a boss portion 7 disposed adjacent to the output hub 1;
and a sleeve 8', which forms an annular gap S between the boss portion 2A and the outer peripheral surfaces 2a and 7a, and is arranged concentrically with the input hub 5 and the output hub 1, and one end 3A is inserted into the notch of the sleeve 8'. 9, the other end 3B is respectively hooked to the notch 10 of the boss portion 7 of the output hub 1, and has a winding habit at least to the boss portion 2A of the input hub 2, and is housed in the gap S. A coil spring 3, a friction member 19 fixed to the end surface of the sleeve 8', and an armature 13 that can freely make frictional contact with the friction member and move in parallel in a direction perpendicular to the axis of the sleeve 8'. ', a field core 6' that movably supports armature 13' only in the axial direction, and a spring 18' that has the tendency to press armature 13' in the direction of sleeve 8'. The clutch B attaches the spring 1 to the front end surface of the bobbin 17' around which the electromagnetic coil 16 is wound.
A spring receiving portion 17'A for housing the spring 8' is provided.

If the spring 18' is a compression coil spring with a small coil diameter, it shall be installed at 3 to 5 equally divided positions in the circumferential direction, but if it is a compression coil spring with a large coil diameter, only one spring 18' will be used in a concentric arrangement. do. Also,
It may be a leaf spring, but in either case it must have an elastic pressing force capable of strongly pressing the armature 13' against the friction member 19.

Furthermore, the spacing between the boss portion 7 and the field core 6' is maintained by the collar 11, and the field core 6' is formed by integrally joining the inner pole 6'A and the outer pole 6'B. Although similar to the conventional one, the field core 6' has convex portions 20 arranged at least 3 to 5 equal angles at the tip of the outer pole 6'B, and corresponding notches 21 of the armature 13' are formed in these convex portions. In mesh with each other, the armature 13' is supported movably only in the axial direction.

Note that the field core 6' is fixed to a device frame or the like via the mounting plate 5, and a driven machine shaft 22 or the like is inserted and fixed to the output hub 1.

In the electromagnetic spring clutch B of this invention having the above-described structure, when the electromagnetic coil 16 is in the state shown in FIG. ′
It is in pressure contact with the friction member 19 of.

In this state, the coil spring 3, which has the habit of tightening the boss portion 2A of the input hub 2, expands in diameter as the input hub 2 rotates, so it cannot be tightened, and the torque of the input hub 2 is transferred to the output hub 1 side. Not communicated.

In other words, torque transmission is interrupted.

Next, when voltage is applied to the electromagnetic coil 16,
Since the armature 13' is magnetically attracted toward the field core 6' and separated from the friction member 19, the sleeve 8' becomes free and the coil spring 3 strongly tightens the boss portion 2A of the input hub 2.

As a result, torque is transmitted from the input hub 2 to the output hub 1.

As is clear from the above description, the electromagnetic coupling clutch of this invention, which presses the armature against the sleeve via a friction member and restrains the sleeve, allows the armature to move only in the axial direction so as to move in parallel, and Since the entire surface is in contact with the member, it is possible to strongly restrain the sleeve even with a relatively small pressing force, but unlike the conventional concave-convex engagement type, the sleeve can be unconstrained even by a slight armature retreat, improving operability. It has excellent advantages such as extremely high reliability.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing a conventional electromagnetic spring clutch, and FIG. 2 is a longitudinal side view showing an embodiment of the electromagnetic spring clutch of the present invention. In the drawings, B...The electromagnetic spring clutch of this invention, 1
...Output hub, 2...Input hub, 2A...Boss part, 2a...Outer peripheral surface, 3...Coil spring,
3A, 3B... End, 4... Groove pulley, 5... Mounting plate, 6, 6'... Field core, 6A, 6'A
...Inner pole member, 7...Boss part, 7a...Outer peripheral surface,
8, 8'... Sleeve, 8a... Inner peripheral surface, 9, 1
0...Notch, 11...Color, 13,13'...
Armature, 16... Electromagnetic coil, 17,1
7'...Bobbin, 18, 18'...Spring, 19...
Friction member, 20... protrusion, 21... notch.

Claims (1)

[Scope of utility model registration request] Input hub 2 that rotates together with input rotating member 4
, an output hub 1 having a boss portion 7 disposed adjacent to the boss portion 2A of the input hub 2, and the boss portion 2A of the input hub 2.
A sleeve 8' is formed with an annular gap S between the outer peripheral surfaces of the input hub 2 and the output hub 1, and is arranged concentrically with the input hub 2 and the output hub 1 so as to be freely rotatable. are respectively hooked to the boss portions 7 of the output hub 1, and at least the boss portions 2 of the input hub 2
The coil spring 3 for winding is housed in the gap S, the friction member 19 is fixed to the end face of the sleeve 8', and the friction member 19 is capable of freely coming into frictional contact with the friction member. an armature 13' oriented perpendicular to the axis of the sleeve 8';
A field core 6' that movably supports this armature only in the axial direction, and a spring 1 that has the habit of pressing the armature 13' in the direction of the sleeve 8'.
An electromagnetic spring clutch comprising 8'.