JPS61160633A - Solenoid spring clutch - Google Patents

Abstract

PURPOSE:To make a spring windable gradually on a hub winding surface and a rotor winding surface as well as to reduce a degree of impact torque in time of connection so sharply, by working a coil spring into a taper form. CONSTITUTION:A coil spring 206 is formed into a taper form on which a diame ter expands toward the side of an armature 150. Therefore, in time of clutch connection, or when the coil spring 206 rolls a winding surface 1a of an input rotor 1 and a winding surface 4a of a hub 4 tight, first tight winding is started from an end part at the smaller side in diameter of the coil spring 206. There fore, the tight winding is started from the winding surface 4a of the output hub 4, then winding takes place gradually toward the winding surface 1a of the input rotor 1. Accordingly, in time of the clutch connection, impactive torque is preventable from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic spring clutch for intermittent power transmission, and is suitable for use, for example, to intermittently drive a refrigerant compressor in an automobile air conditioner. It is something.

[Conventional technology]

As shown in the vertical cross-sectional view of FIG. 8, the conventional electromagnetic spring clutch includes an input rotor 1 which is a rotary driving body, and mt&, 2a built in the input rotor I and installed in the front housing (f) 1 of the compressor. , stay 2b, bearing (f
The excitation coil 2 is attached by the circlip (f) 8 through the inner race of ) 9, and by applying voltage to this coil 2 and exciting the magnetic circuit section around the excitation coil 2, it is magnetically attracted. An armature 150 is frictionally engaged with a friction surface 1b provided on one end surface of the input rotor 1 and rotates integrally with the armature 150. A hook portion 6a at one end is engaged with a notch 151 formed in this armature 150, and a hook portion 6a at the other end is attached. The part 6b is provided with a coil spring 6 that engages with a notch 41 provided in the output hub 4, which is a rotating driven body, and when the excitation coil 2 is energized, the coil spring 6 protrudes from the input rotor l in the axial direction. The cylindrical spring winding surface 1a is wound around the winding surface 1a of the output hub 4, and the torque of the input rotor 1 is transmitted to the output hub 4 by this winding force. )2 and oak)
(f) 3 and is transmitted to the rotating shaft (f) 4 of the compressor, which is fixed.

Further, the coil spring 6 is housed in a spring cover 170 that is concentrically attached to the output hub 4, and the armature 150 is supported by a flange 171 of the input rotor of the spring cover 170. Further, the input rotor 1 is supported by a bearing (f) 9 attached to the outer periphery of the front housing (f) 1 of the compressor. It is fixed by clip (f)B.

When the excitation coil 2 is turned off, the armature 150 is attracted to the spring cover 170 by a permanent magnet 173 fixed to the flange portion 171 of the spring cover 170 by adhesive or the like, and the spring 6 is returned to its original shape. There is.

[Problem that the invention seeks to solve]

However, in the conventional electromagnetic spring clutch having the above configuration, the coil spring 6 is connected to the cylindrical spring winding surface 1a of the input rotor 1 (output hub 427).
Since the gaps between the coil spring 6 and the winding surface 1a of the rotor 1 and the winding surface 4a of the output hub 4 are constant when the coil spring 6 is wound around the winding surface 4a of the rotor 1, after the excitation coil is energized, the coil spring 6 Wrapping surface 1a of hub 1 and winding surface 4a of hub 4
It wraps around evenly and tightly. For this reason, the torque transmitted to the output hub 4 side rises instantaneously, and an impact torque is generated on the rotary shaft (f) 4 of the compressor, which induces noise in the passenger compartment and deteriorates the feeling of the occupants. This damaged the joint between the output hub 4 and the rotary shaft (f) 4 of the compressor by the key (f) 2, significantly shortening its lifespan. Further, as the clutch is repeatedly engaged and engaged, the coil spring 6, the winding surface 1a which is the winding part of the coil spring 6, and the winding surface 4a of the output hub 4 wear out, and when this wear becomes severe, the winding surface 1a The coil spring 6 enters the gap g between the abutting portion of the output hub 4 and the output hub 4. At this time, a thrust load is applied to the output hub 4, causing problems such as adversely affecting the durability of the compressor.

In view of the above-mentioned problems, the present invention reduces the impact torque at the time of connection and eliminates the coil spring from digging into the gap g by gradually winding the coil spring from one end to the other end. With the goal.

[Means for solving problems]

In order to achieve the above objects, the present invention provides: (a) an input rotor to which rotation is transmitted from a drive source; (b) a friction surface formed on one end surface of this input rotor; (d) an excitation coil that generates magnetic flux when energized to attract the armature to the friction surface of the input rotor; (e) an output coupled to the driven shaft; a hub; (n) a cylindrical wrapping surface protruding from the friction surface of the input rotor; and a coil spring having a hook portion at the other end locked to the armature and a hook portion at the other end locked to the output hub, and (h) the outer diameter of the coil spring is formed into a tapered shape. Adopt means.

[For production]

According to the above technical means, when the clutch is connected, the tapered coil spring moves from the end with a smaller diameter (for example, the end on the side of the output hub) to the end with a larger diameter (for example, the end on the armature side). Since the coil spring is gradually wound toward the winding surface of the input rotor and the output hub, the coil spring is gradually wound around the winding surfaces of the input rotor and the output hub, thereby alleviating the impactful torque transmission.

〔Example〕

Next, the present invention will be described in detail with reference to the accompanying drawings.

Figures 1 to 4 show an embodiment of the present invention, in which an excitation coil 2 is built into the input rotor 1 with a slight gap in between.
, is attached to a front housing (f) 1 of an automobile air conditioning compressor by a circlip (f) 8 via an inner race of a bearing (f) 9. An input rotor 1 is rotatably supported by a front housing (f) 1 of an automobile air conditioning compressor via the bearing (f) 9.

An output hub 4 is fixed to a rotating shaft of the compressor, that is, a driven shaft (f) 4, via a key (f) 2 and a nut (f) 3.

A cylindrical winding surface 1a and a friction surface 1b are formed on one end surface of the input rotor 1, and an armature 150 is disposed facing each other on the friction surface 1b. A hook portion 206a at one end of the coil spring 206 is locked. A hook portion 206b at the other end of the coil spring 206 is engaged with a notch 41 provided in the winding surface 4a of the output hub 4. As shown in FIGS. 1 and 3, this coil spring 206 is formed in a tapered shape whose diameter increases from a hook portion 206b on the output hub side toward a hook portion 206a on the armature side. Therefore, the gap S between the inner circumference and the outer circumference of the tapered coil spring 206, the winding surface 4a of the hub 4, and the winding surface 1a of the rotor l becomes larger toward the armature side hook portion 206a.

In addition, the input rotor 1 receives power extracted from a drive source (for example, an automobile engine) (not shown) via a belt (not shown), and the magnetic flux generated when voltage is applied to the excitation coil 2 is applied to the arcuate shape of the input rotor 1. The magnetic attraction force is generated by bypassing the slit 1c and passing through the armature 150.

A groove 1d into which the belt fits is provided on the outer periphery of the input rotor 1.

In this example, the input rotor 1, the yoke 2a around the excitation coil 2, the armature 150, the coil spring 206, the spring cover 170, and the output hub 4 that form the magnetic circuit are all made of iron-based materials.

A plurality of permanent magnets 173 are fixed to the back side of the armature 150 in the cover 170 by adhesive or the like, and when the excitation coil 2 is deenergized, the magnets 17
3, the armature 150 is held by suction. The cover 170 is provided with a protrusion 275 (see FIG. 4) that protrudes toward the inner circumference of the armature 150.
By supporting the inner peripheral surface of the armature 150, eccentricity of the armature 150 during operation is suppressed. This protrusion 275
As shown in FIG. 4, a slit 276 is provided to allow the hook portion 206a at one end of the coil spring 206 to move by a predetermined angle necessary until the hook portion 206a is completely wound.

Next, the operation of this embodiment in the above-described configuration will be explained.

First, when a voltage is applied to the excitation coil 2, the magnetic circuit around it and the armature 150 are excited, and as a result, the armature 150 rotates together with the input rotor 1, which is magnetically attracted to the friction surface 1b of the input rotor l. The rotation of the armature 150 tightens the coil spring 206 onto the winding surface 1a of the input rotor 1 and the winding surface 4a of the output hub 4, and the torque transmitted to the input rotor 1 is transmitted through the output hub 4 to the compressor. It is transmitted to the rotating shaft (f) 4. Here, in this example, the coil spring 206 is shown in FIG.
As shown in FIG. 3, since the coil spring 206 is formed in a tapered shape whose diameter increases toward the armature 150 side, when the clutch is connected, the coil spring 206 is connected to the winding surface 1a of the input rotor 1 and the winding surface of the hub 4. 4a, the winding is first started from the smaller diameter end of the coil spring 206. Therefore, the winding is started from the winding surface 4a of the output hub 4, and then the winding surface 1a of the input rotor 1 is tightened.
Winding occurs gradually towards the end.

Therefore, there is no sudden winding that occurs in the conventional parallel coil spring 6 shown in FIG. This problem can be resolved.

Next, when the excitation coil 2 is de-energized, the armature 150 is released from the friction surface 1b of the input rotor 1.
The attractive force of the permanent magnet 173 returns the coil spring 206 to its original position, and the coil spring 206 also comes out of its frictional engagement with the winding surface 1a of the input rotor 1 and the winding surface 4a of the hub 4 due to its own restoring force, thereby reducing the torque. Transmission is definitely released.

In the above-described embodiment, the coil spring 206 is formed into a tapered shape whose diameter increases toward the armature 150, so that the coil spring 206 is formed in a tapered shape whose diameter increases toward the armature 150 side. coil spring 20
As shown in FIGS. 5 to 7, the coil spring 306 is wound around the armature 1 gradually.
50 in a tapered shape whose diameter increases toward the output hub 4 side, from the winding surface 1a of the input rotor 1 to the output hub 4.
A similar effect can be obtained by winding the coil spring 306 gradually toward the winding surface 4a.

Furthermore, in each of the above embodiments, the coil spring 206
, 306 into which the hook portions at both ends are engaged.
41 is preferably subjected to hardening treatment such as induction hardening to improve wear resistance.

In addition, the permanent magnet 17 is used as a return force for the armature 150.
3 was used, but instead of the magnet 173, a spring means such as a plate spring or a coil spring, or an elastic body such as rubber may be used.

〔Effect of the invention〕

As explained above, according to the present invention, by processing the coil spring into a tapered shape, it is possible to gradually wrap the spring around the hub winding surface and the RONITA winding surface, thereby reducing the shock at the time of connection. Since the torque can be significantly reduced, it is possible to eliminate the operating noise and the spring biting into the gap g as in the conventional structure, and it has the great effect of greatly improving clutch durability.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an electromagnetic spring clutch showing an embodiment of the present invention, Fig. 2 is a front view of the coil spring shown in Fig. 1, Fig. 3 is a side view of Fig. 2, and Fig. 4 is the first
5 is a longitudinal sectional view of an electromagnetic spring clutch showing another embodiment of the present invention, and FIG.
A front view of the coil spring shown in the figure, FIG.
FIG. FIG. 8 is a longitudinal sectional view showing a conventional electromagnetic spring clutch, FIG. 9 is a front view of a coil spring used in the conventional electromagnetic spring clutch, and FIG. 1O is a side view of FIG. 9. 1...Input rotor, 1a...Rotor side winding surface, ■b
...Friction surface, 2...Exciting coil, 4...Output hub, 4a...Hub side winding surface, 6,206,306...
Coil spring, 6a, 206a, 30
6 a, 6 b, 206b, 306b... hook portion, (f) 4... driven shaft, 150... armature, 170... spring cover O

Claims (3)

[Claims] (1) (a) An input rotor to which rotation is transmitted from a drive source, (b) A friction surface formed on one end surface of this input rotor, (c) An armature installed opposite to the friction surface of this input rotor. (d) an excitation coil that generates magnetic flux when energized to attract the armature to the friction surface of the input rotor; (e) an output hub coupled to the driven shaft; and (f) the input rotor. (g) a cylindrical wrapping surface protruding from the friction surface of the output hub; (h) an electromagnetic spring clutch comprising: a coil spring whose hook portion at the other end is engaged with the output hub; and the outer diameter of the coil spring is tapered. (2) The electromagnetic spring clutch according to claim 1, wherein the coil spring is formed in a tapered shape whose diameter increases from the output hub side toward the armature side. (3) The electromagnetic spring clutch according to claim 1, wherein the coil spring is formed in a tapered shape whose diameter increases from the armature side toward the output hub side.