JPH0814276A - Electromagnetic clutch - Google Patents

Abstract

PURPOSE:To provide an electromagnetic clutch in which balancing function is added to an armature support member made of reinforced plastic material. CONSTITUTION:An armature hub 10 is installed to the rotating shaft 8 of a compressor 2 in such a manner as to be integrally rotatable. An armature support member 12 made of reinforced plastic material which has a damper rubber housing part 13 is integrally fixed to the armature hub 10 by insert molding. A balance weight for canceling the dynamic unbalance of the compressor 2 is buried in the armature support member 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch mounted on a compressor for a car air conditioner, and more particularly to an electromagnetic clutch having a balancing function such as a balance weight for canceling dynamic unbalance of the compressor. It is a thing.

[0002]

2. Description of the Related Art Conventionally, an oscillating compressor or the like has a dynamic imbalance due to its structure and operation. Therefore, an electromagnetic clutch having an armature assembly mounted on the rotary shaft of the compressor is not allowed to move. Balance weights are configured to offset the imbalance. That is, Japanese Examined Japanese Patent Sho 56-
As in the electromagnetic clutch for a compressor disclosed in Japanese Patent No. 31450, an armature assembly mounted on a rotary shaft of a compressor, and a washer and a base end portion of a leaf spring on a flange portion of the armature hub. In order to offset the dynamic unbalance of the compressor by the stopper plate fixed via the armature and the armature whose free end of the leaf spring is fixed and the retracted position is limited by the protrusion of the stopper plate. The balance weight of is formed integrally.

Therefore, when the compressor is driven by magnetically attracting the armature to the rotor, which is rotationally transmitted from the drive source by the V-belt, the dynamic unbalance of the compressor is such that the balance weight is formed on the armature assembly. Since it is canceled by the dynamic imbalance that occurs in the compressor, it is possible to suppress vibration during driving of the compressor.

[0004]

In a conventional electromagnetic clutch, a stopper plate made of a metal material is provided with projections and notches to add a balancing function. However, for the purpose of weight reduction and productivity of the electromagnetic clutch, in the damper rubber type electromagnetic clutch, the mainstream of the product is to form the armature support member that stores the damper rubber that movably supports the armature in the axial direction with reinforced plastic. Is coming. Therefore, even if the armature support member made of such a reinforced plastic material is provided with a balancing function composed of the protrusions and the notches, the armature support member itself does not perform a sufficient balancing action because it is lightweight. It is an object of the present invention to provide an electromagnetic clutch in which an armature support member made of a reinforced plastic material has a balancing function.

[0005]

In order to achieve such an object, in an electromagnetic clutch of the present invention, an armature hub mounted on a rotary shaft and an armature made of a reinforced plastic material integrally formed with the armature hub are provided. A support member, a plurality of damper rubber storage portions protruding from the outer peripheral side of the armature support member at circumferential intervals, a damper rubber press-fitted into the damper rubber storage portion, and fixed to the damper rubber. And a fastening member penetrating the armature support member, an armature supported by the damper rubber via the fastening member and movable in the axial direction, and an exciting device for magnetically attracting the armature against the elasticity of the damper rubber. The balance weight is embedded in the armature support member.

[0006]

The electromagnetic clutch drives the compressor equipped with the armature assembly having the armature by magnetically attracting the armature to the rotor to which the rotation of the automobile engine is transmitted. The dynamic unbalance inside the compressor is canceled by the dynamic unbalance due to the balance weight embedded in the armature support member of the armature assembly.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an electromagnetic clutch according to the present invention, and FIG.
1 is a cross-sectional view of FIG. 1, FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2, FIG. 4 is a cross-sectional view illustrating a method of manufacturing an armature support member, FIG. 5 is an enlarged view of a main part of FIG. 2, and FIG. FIG. 7 is a cross-sectional view of an essential part for explaining the influence of the inclination strain in the inside, and FIG. In these drawings, an electromagnetic clutch generally designated by 1 is attached to a car air-conditioner compressor 2 and is used as a power transmission device for transmitting or interrupting rotation of an automobile engine to the compressor 2. . Reference numeral 3 denotes a rotor rotatably supported by a cylindrical portion 2a of the compressor 2 via a bearing 2b, and a poly V groove pulley 4 made of a plastic material is integrally formed on the outer peripheral surface of the rotor 3. . Denoted at 3a and 3b are magnetic field detouring slits formed by punching and are provided on the same circumference at intervals. The rotor 3 and the pulley 4 are formed by insert-molding the rotor 3 as an insert in a mold of an injection molding machine and injecting a plastic material into the mold from a gate. This molding method is disclosed in Japanese Patent Laid-Open No. 4-290618. A field core 6 in which an electromagnetic coil 5 is installed as an exciting device is fitted in the annular groove of the rotor 3, and the field core 6 is screwed and fixed to the housing of the compressor 2 via a mounting plate 7. .

An armature assembly 9 is integrally rotatably mounted on the rotary shaft 8 of the compressor 2. The armature assembly 9 is formed of these members and a reinforced plastic, with an armature hub 10 made of a metal material fitted to the rotary shaft 8 by serration and a contact plate 11 with which the tip of the rotary shaft 8 abuts as an insert. It has a structure in which a disc-shaped plate 12 as an armature support member is integrated by insert molding. The armature hub 10
It comprises a boss portion 10a having a serration groove formed on the inner peripheral surface thereof, which fits on the rotating shaft 8, and a disc-shaped flange portion 10b extending radially outward from the end surface of the boss portion 10a.
In the flange portion 10b, a plurality of (six in this embodiment) engagement holes 10c formed at equidistant positions on the same circumference, and a rivet to be described later that is cut out in a semi-circular shape on the outer peripheral edge. A plurality of (three in the present embodiment) escape portions 10d for 14 are formed.

On the outer peripheral side of the plate 12, a plurality (three in this embodiment) of recessed rubber damper accommodating portions 13 are formed at equal positions on the same circumference, and a cylindrical accommodating wall 12 is provided.
A disk portion 12b which is surrounded by a and is located near the center
A protrusion 12c serving as a rotation stopping portion that engages with the engagement hole 10c of the armature hub 10 is integrally formed therewith. The storage wall 12a of the damper storage portion 13 is provided with a protrusion 121a having a height L2 that is higher than the height L1 of the rivet 14, which will be described later. At the tip of the protruding portion 12c, there is integrally formed a retaining portion 12d that is formed in a flat shape on the rotor 3 side of the flange portion 10b of the armature hub 10. The plate 12 includes a disc portion 12b and a retaining portion 12d. It is integrated with the armature hub 10 by sandwiching the flange portion 10b. Further, the inner peripheral edge of the plate 12 has a cylindrical portion 12e that functions as a retaining member for the contact plate 11, and the outer peripheral edge has a cylindrical cover 12f.
Each is integrally formed.

Reference numeral 14 designates a rivet as a fastening member whose end on the opening side of the storage portion 13 is chamfered in an arc shape.
Is a damper rubber to which the rivet 14 is fixed at the center, and is press-fitted and fixed to the damper rubber storage portion 13 of the plate 12. The tip of the rivet 14 is projected from the through hole 12g formed in the bottom surface of the storage portion 13 toward the rotor 3 side, and is caulked and fixed to the armature 16. In addition, the caulking fixing structure of the armature 16 with the rivet 14 is as follows.
It is disclosed in Japanese Utility Model Laid-Open No. 4-32327. 16a
Is a slit for detouring the magnetic field and is provided at intervals on the same circumference.

The inner diameter of the armature 16 is smaller than the outer diameter of the flange portion 10b of the armature hub 10, and the elasticity of the damper rubber 15 causes the armature 16 to move to the flange portion 10 of the armature hub 10.
It is in contact with b. Here, the contact surface of the flange portion 10b that contacts the armature 16 is formed to be slightly higher in height than the facing surface of the plate 12 that faces the outer peripheral edge of the armature 16, and the space between the armature 16 and the plate 12 is reduced. A void G is provided in the.

On the other hand, the electromagnetic clutch 1 of such an embodiment
In FIG. 3, the balance weight 17 is embedded in the outermost peripheral portion of the plate 12. This balance weight 17
Is supported in a pair of molds like the armature hub 10 and is insert-molded on the plate 12. That is, as shown in the sectional view of FIG. 4, the boss portion 10a of the armature hub 10 is fitted into the recessed portion 18a formed in the center of the fixed mold 18, and the protrusion 19a provided on the movable mold 19 is provided. Hook the balance weight 17 on. Then, the movable mold 19 is brought into contact with the fixed mold 18 to form a space defining the plate 12. At this time, the movable mold 19
The projecting portion 19b formed at the center of the abutment plate abuts on the backing plate 11 fitted to the end of the shaft hole of the armature hub 10.
A plastic material is injected into the space from a gate (not shown) and insert-molded.

Next, the operation of the electromagnetic clutch constructed as described above will be described. The magnetic flux Φ generated by energizing the electromagnetic coil 5 is diverted from the rotor 3 to the armature 16 by the slits 3a, 3b, 16a.
Return to the double flux type magnetic flux path. Due to the magnetic attraction of the magnetic flux, the armature 16 is magnetically attracted to the rotor 3 against the elasticity of the damper rubber 15, and the rotation of the automobile engine is transmitted to the car air-conditioner compressor 2.
Further, since the magnetic flux Φ disappears when the electromagnetic coil 5 is de-energized, the elasticity of the damper rubber 15 causes the armature 1 to move.
6 is separated from the rotor 3 and retracts to the flange portion 10b of the armature hub 10. The dynamic imbalance of the car air-conditioning compressor 2 being driven is canceled by the action of the balance weight 17.

Next, by repeating the operation, the plate 12
A case in which the outer peripheral end side of the item has a tilt distortion will be described with reference to FIG. Flange portion 10b that abuts the armature 16
The contact surface of is formed slightly higher than the facing surface of the plate 12 facing the outer peripheral edge of the armature 16,
A gap G is provided between the armature 16 and the plate 12, and if this gap G is set to be larger than the inclination strain on the outer peripheral end side of the plate 12, an inclination strain of α occurs on the outer peripheral end side of the plate 12. However, the gap G1 is still formed. Therefore, even in the non-excited state in which the power supply to the electromagnetic coil 5 is cut off, the gap between the armature 16 and the rotor 3 is maintained, and the armature 16 is vibrated by external vibration.
The problem that the rotor is hit by the rotor 3 or the armature 16 and the rotor 3 slip and rotate is eliminated.

Next, the case where the damper rubber 15 falls off will be described with reference to FIG. Automobiles equipped with an electromagnetic clutch for car air conditioners may be exported to countries with extremely hot climates.In this case, friction heat generated by repeated operation and heat generated from the engine are also added to the electromagnetic clutch. It is predicted that the damper rubber 15 that is baked and fixed to the rivet 14 and that is fitted and fixed in the damper housing portion 13 will fall off in the worst case. In such a case, the elastic return of the rivet 14 by the damper rubber 15 is not performed, the electromagnetic clutch 1 is locked, and in this state, the power transmission state to the car air-conditioning compressor is continued, as shown in FIG. So that rivets 14
Dissolves the accommodated storage wall 12a, further dissolves the plate 12 as indicated by the chain double-dashed line 14a, and finally dissolves to the adjacent storage wall 12a. However, since the storage wall 12a is provided with the protrusion 121a that protrudes beyond the head of the rivet 14, the protrusion 121
Since a remains as a non-dissolved portion and the plate 12 is not separated by the protruding portion 121a, it is possible to prevent a part of the plate 12 from being separated and scattered.

[0016]

As described above, according to the present invention, the balance weight for canceling the dynamic imbalance generated inside the car air conditioner compressor is embedded in the armature support member made of the reinforced plastic material. , The balance function could be added to the lightweight electromagnetic clutch.
Moreover, since the balance weight is embedded in the armature support member, no special assembly process is required and the productivity is improved. Furthermore, it is economical because only the weight of the balance weight needs to be changed with respect to the difference in dynamic unbalance depending on the type of car air conditioner compressor, and no special design change is required.

Further, in the electromagnetic clutch of the present invention, the armature hub is formed with a flange portion having a plurality of engaging holes formed therein, and the retaining portion engaging with the engaging holes is integrally formed with the armature support member. Therefore, the retaining portion enhances the mechanical strength of the connection between the armature hub and the armature support member, and improves the reliability in terms of quality.

Furthermore, in the electromagnetic clutch of the present invention, since the relief portion of the fastening member is formed on the flange portion of the armature hub, the fastening member can be brought closer to the armature hub by the amount of the relief portion formed. The outer diameter size can be reduced.

Further, in the electromagnetic clutch of the present invention, the inner peripheral edge of the armature is brought into contact with the flange portion of the armature hub, and the contact surface of the flange portion of the armature support member facing the outer peripheral edge of the armature. Since the surface height is higher than that of the facing surface, the armature that retreats due to the elasticity of the damper rubber keeps its retracted position constantly at the flange part of the armature hub, and the elasticity of the damper rubber allows the armature support member to move in the axial direction. Even if slight distortion occurs, the retracted position of the armature does not change.Therefore, external vibration may cause the armature to hit the rotor, etc., which may cause unpleasant noise, or the armature and the rotor may frictionally contact each other when not excited. It is possible to prevent quality problems such as uneven wear of the armature. .

[Brief description of drawings]

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

FIG. 2 is a sectional view of FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a cross-sectional view illustrating the method of manufacturing the armature support member.

FIG. 5 is an enlarged view of a main part of FIG.

FIG. 6 is a cross-sectional view of an essential part for explaining the influence of tilt distortion during operation in the electromagnetic clutch according to the present invention.

FIG. 7 is a front view for explaining the operation of the electromagnetic clutch according to the present invention after the damper rubber has fallen off.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic clutch, 9 ... Armature assembly, 10 ... Armature hub, 10b ... Flange part, 12 ... Plate, 12a ... Damper storage wall, 121a ... Projection part, 12
c ... rotation prevention part, 12d ... retaining part, 13 ... damper rubber storage wall, 14 ... rivet, 15 ... damper rubber, 1
6 ... Armature, 17 ... Balance weight.

Claims (4)

[Claims] 1. An armature hub mounted on a rotating shaft,
An armature support member made of a reinforced plastic material integrally formed with the armature hub, a plurality of damper rubber accommodating portions projecting from the outer peripheral side of the armature support member at circumferential intervals, and the damper rubber accommodating portion. A damper rubber press-fitted into the damper, and a fastening member fixed to the damper rubber and penetrating the armature support member,
An armature supported by the damper rubber via the fastening member and movable in the axial direction, and an exciting device for magnetically attracting the armature against the elasticity of the damper rubber are provided, and a balance weight is attached to the armature support member. An electromagnetic clutch characterized by being buried. 2. A flange portion having a plurality of engaging holes formed in the armature hub, and a retaining portion engaging with the engaging hole is integrally formed with the armature support member. The electromagnetic clutch according to claim 1. 3. The relief portion of the fastening member is formed on a flange portion of the armature hub.
The described electromagnetic clutch. 4. The inner peripheral edge of the armature is brought into contact with a flange portion of the armature hub, and the contact surface of the flange portion is more than the facing surface of the armature support member facing the outer peripheral edge of the armature. The electromagnetic clutch according to claim 2, wherein the electromagnetic clutch is formed to have a surface height.