JP2577524Y2 - Electromagnetic coupling device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic coupling device such as an electromagnetic clutch or an electromagnetic brake, and more particularly to a hub having an armature supported by an elastic member so as to be movable only in the axial direction. The present invention relates to an electromagnetic coupling device configured as a series arrangement of a damper rubber and a leaf spring when viewed from above.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic coupling device in which a damper rubber and a leaf spring are arranged in series and an armature is supported on a hub has been proposed in Japanese Utility Model Laid-Open No. 62-141931. Such an electromagnetic coupling device includes a hub mounted on a rotating shaft such as a compressor for a car air conditioner, a plurality of through holes formed in a flange of the hub and dividing the circumferential direction of the flange into three equal parts, Sleeves connected by damper rubber in the holes, a plurality of leaf springs individually fixed to the ends of each sleeve by rivets inserted into the sleeves, and an armature to which the free ends of these leaf springs are fixed. It has.

In addition, the leaf spring extending in a tangential direction of a reference circle concentric with the hub has a short rectangular piece extending from a fixing point with the hub (hereinafter referred to as a base end) to a side opposite to the free end. Are formed, and stopper rubbers are individually arranged between the short rectangular piece and the armature.

Accordingly, in the electromagnetic coupling device having such a structure, for example, rotation of an engine is transmitted by energizing an electromagnetic coil to magnetically attract an armature to a rotor (referred to as a pulley in the above publication). The rotation of the rotating rotor is transmitted to the rotating shaft of the compressor.

In general, the purpose of forming such an elastic member having a damper rubber and a leaf spring in series is that if only the damper rubber is used, its spring constant is large, and a large amount of deflection cannot be set due to its spring load characteristics. Because. That is, if the gap between the armature and the rotor (hereinafter, referred to as an air gap) increases due to wear, the spring load of the damper rubber increases rapidly, and in such an electromagnetic coupling device using only the damper rubber, the electromagnetic coil This is because the magnetic attraction force of the armature must be set large by increasing the minimum attraction voltage of the armature.

[0006]

However, in the conventional electromagnetic coupling device which has solved the above-mentioned problems, a conventional rubber coupling device is provided with a stopper rubber against the base end portion of the leaf spring in order to suppress the vibration caused by external vibration acting on the armature. The free end of the leaf spring is bent toward the rotor side, and an initial reaction force (hereinafter, referred to as “reaction”)
However, such a set load is not set for the damper rubber, and the deflection of the armature cannot be suppressed. Further, if the rigidity of the damper rubber is increased so that the armature can be prevented from running without applying a set load to the damper rubber, the damping effect of the damper rubber at the time of rotation transmission, which is the original purpose, is reduced. This invention aims to solve such a problem.

[0007]

In order to achieve such an object, the present invention comprises a plurality of rivets connected to a flange of a hub by a damper rubber and extending in a direction of a center axis of the hub. An electromagnetic coupling device in which a base end of a leaf spring having a free end fixed to an armature disposed concentrically with the damper rubber is connected by the rivet to the damper rubber. A large-diameter portion facing the hole and a small-diameter portion protruding from the through-hole, the large-diameter portion having a small-diameter-portion-side end surface as an abutting surface of the leaf spring; By inserting a small diameter portion of the rivet into a through hole formed in the through hole and plastically processing the tip, the base end side surface of the leaf spring is brought into contact with the flange side surface of the hub by the set load of the damper rubber. ,this Characterized in that the flange side of the probe and the plate spring abutting surface of the rivet is configured on the same plane.

[0008]

When the armature is magnetically attracted to the rotor by energizing the electromagnetic coil, the armature is magnetically attracted to the rotor against the spring load of the leaf spring and the damper rubber. When the power supply to the electromagnetic coil is cut off, the armature is separated from the rotor by the elastic restoring force of the leaf spring and the damper rubber.

[0009]

1 and 2 show an electromagnetic clutch as an electromagnetic coupling device according to an embodiment of the present invention. FIG.
FIG. 2 is a sectional view taken along line AA of FIG. The electromagnetic coupling devices shown in these drawings are configured as electromagnetic couplings that transmit the rotation of an automobile engine to a compressor for a car air conditioner.

A hub 3 having a flange 3a is mounted on a rotating shaft 2 projecting from a cylindrical portion 1a of the compressor 1 so as to be integrally rotatable. The flange 3a of the hub 3 has a substantially triangular shape in a front view. The stopper plate 4 is fixed with rivets. The stopper plate 4 is configured to further extend the flange 3 a of the hub 3 radially outward, and is a flange member of the hub 3.

A plurality of damper covers 5 are welded to the stopper plate 4 at positions that divide the circumferential direction into three equal parts and are on the same circumference. A rivet 6 extending in the direction of the central axis is connected by a damper rubber 7. The rivet 6 has a headed cylindrical shape, and has a large-diameter portion 6 a to which a damper rubber 7 is fixed and faces a through hole 4 a formed in the stopper plate 4 and protrudes from a side surface of the stopper plate 4. It has a small diameter portion 6b.

A base end of a leaf spring 9 having a free end fixed to the armature 8 is fixed to the small diameter portion 6b of the rivet 6. The leaf spring 9 is formed of a rectangular thin plate having a width larger than the diameter of the through hole 4 a formed in the stopper plate 4, and the peripheral edge of the through hole formed in the base end portion corresponds to the large diameter portion 6 a of the rivet 6. Small diameter side end surface (contact surface of leaf spring 9)
6 c, and the outer edge of the base end is in contact with the peripheral edge of the through hole 4 a of the stopper plate 4.

The contact surface 6c of the rivet 6 is shifted from the side of the armature 8 of the stopper plate 4 toward the damper rubber 7 before the tip of the small diameter portion 6b of the rivet 6 is subjected to plastic working. The tip of the rivet 6 is subjected to plastic working as shown in FIG.
The armature 8 side surface of the stopper plate 4 is aligned with the side surface on the same plane. A set load is applied to the damper rubber 7 by such plastic working. The leaf spring 9 has a larger spring constant than the leaf spring of the electromagnetic coupling device in which only the leaf spring is provided as an elastic member, and no set load is applied to the leaf spring 9.

On the other hand, the armature 8 is opposed to a rotor 10 rotatably supported via a bearing on the cylindrical portion 1a of the compressor 1 with an air gap G therebetween. The rotor 10 has a V groove 1 around which a V belt (not shown) is stretched.
0a and the field core 1 in which the electromagnetic coil 11 is installed
2 has an annular groove 10b fitted therein. The field core 12 is fixed to the compressor 1 via a mounting plate 13. Further, the leaf spring 9 has a structure sandwiched between the stopper plate 4 and the armature 8.

In the electromagnetic coupling device having the above structure, when the electromagnetic coil 11 is energized and the armature 8 is magnetically attracted to the rotor 10, the armature 8 resists the load of the leaf spring 9 and the damper rubber 7 against the spring load. The rotation of the rotor 10 is transmitted to the rotating shaft 2 of the compressor 1. When the power supply to the electromagnetic coil 11 is stopped, the armature 8 is separated from the rotor 10 by the elastic return force of the leaf spring 9 and the damper rubber 7.

Here, when the air gap G between the armature 8 and the rotor 10 is set to 1.0 mm, the leaf springs 9 are respectively bent so that the leaf spring 9 bends about 0.7 mm first and then the damper rubber 7 bends about 0.3 mm. And the spring constant of the damper rubber 7 are set. Further, the set overall spring constant is set smaller than the spring constant of the damper rubber of the electromagnetic coupling device in which only the damper rubber is provided as the elastic member.

Although the stopper plate 4 is fixed to the flange 3a of the hub 3 in the above description, the stopper plate 4 may be omitted by extending the flange 3a of the hub 3 in the radial direction. Also, an electromagnetic clutch is shown as an electromagnetic coupling device.
The present invention can also be applied to an electromagnetic brake that magnetically attracts the magnetic brake.

[0018]

According to the electromagnetic coupling device of the present invention, in the electromagnetic coupling device having a structure in which the leaf spring and the damper rubber are arranged in series as viewed from the power transmission path, the base end of the leaf spring is connected to the leaf spring contact surface of the rivet. The rivet leaf spring contact surface and the hub flange side surface are configured to be on the same plane, so that a set load can be applied to the damper rubber, and the armature is subjected to external vibration. Deflection can be suppressed.

[Brief description of the drawings]

FIG. 1 is a front view of an electromagnetic clutch as an electromagnetic coupling device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of the electromagnetic clutch of FIG. 1;

[Explanation of symbols]

 3 hub 4 stopper plate 5 damper cover 6 rivet 7 damper rubber 8 armature 9 leaf spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A hub having a plurality of rivets connected to a flange of a hub by a damper rubber and extending in a central axis direction of the hub, and having a free end fixed to an armature arranged concentrically with the hub. In the electromagnetic coupling device, the base end of the leaf spring is connected to the damper rubber by the rivet, the rivet has a large diameter portion facing a through hole formed in a flange of the hub and a small diameter projecting from the through hole. The leaf spring has a shape in which a small-diameter-side end surface of a large-diameter portion is an abutting surface of the leaf spring, and the small-diameter portion of the rivet is inserted into a through hole formed in a base end of the leaf spring. By subjecting the tip to plastic working, the base end side surface of the leaf spring is brought into contact with the flange side surface of the hub due to the set load of the damper rubber, and the flange side surface of the hub and the leaf spring contact surface of the rivet Are coplanar An electromagnetic coupling device configured as described above.