JP2002048155A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic clutch which has combined advantage of a flat spring type and a rubber type and has a simple configuration. SOLUTION: A follower side connection part 61a connected to a rotating shaft 8 side of a compressor 7 is formed integral with the inner periphery side of a spring plate member 61 of disc form, an outer periphery ring part 61f opposing to an armature 5 is formed integral with the outer periphery of the spring plate member 61 of disc form, a plurality of flat spring parts 61b which generate spring force to move the armature 5 in a direction away from a rotor are arranged integrally in such a manner to extend radially between the follower side connection part 61a and the outer periphery ring part 61f in the spring plate member 61 of disc form, and the armature 5 and the outer periphery ring part 61f are directly connected therebetween by an elastic member 63.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch for transmitting and interrupting rotational power, and is suitable for use, for example, for intermittent operation of a compressor of a car air conditioner.

[0002]

2. Description of the Related Art Conventionally, an electromagnetic clutch for a compressor of a car air conditioner has a rotor which is rotationally driven by a drive source such as an engine and an armature which is opposed to the rotor with a predetermined minute gap therebetween. The hub structure for connecting the armature to the rotary shaft on the compressor side is roughly classified into the following two types.

That is, one of them is a leaf spring type hub structure in which one end of the leaf spring is connected to an inner hub connected to a rotary shaft on the compressor side, and the other end of the leaf spring is connected to an armature. It is a structure to be connected. The other one is a rubber-type hub structure in which the inner peripheral side of a cylindrical elastic member is connected to an inner hub connected to a rotary shaft on the compressor side, and the outer peripheral side of the elastic member is formed. Is connected to the armature via a holding plate having a cylindrical holding portion.

[0004]

By the way, in the case of the former leaf spring type, an inexpensive iron-based material can be used as the leaf spring material, and a simple connecting means such as rivet connection is used for the connecting portion of the leaf spring material. Therefore, the manufacturing cost can be reduced, and a leaf spring material having a small plate thickness can be used, so that there is an advantage that the axial dimension of the electromagnetic clutch can be reduced. However, on the other hand, the power transmission system from the armature to the hub does not have a damping mechanism for vibration (shock) and torque fluctuation, so that the effect of damping clutch operating noise and torsional resonance of the clutch cannot be expected.

If the rotating shaft of the compressor is locked for some reason, the armature cannot rotate and the rotor slides on the armature to rotate. However, in the case of the leaf spring type, the torque limiter is not used. Since the function (fuse function) cannot be exhibited, the overload operation is continued for a long time, and the belt for transmitting the engine power or the friction surface temperature is abnormally increased due to the slip of the rotor for a long time. Could cause

On the other hand, the latter rubber type can exert the damping effect of the elastic member made of rubber, so that the clutch operating noise and the torsional resonance of the clutch can be reduced as compared with the leaf spring type. Further, if the rotating shaft of the compressor is locked for some reason, the heat generated on the friction surface between the rotor and the armature causes the temperature of the elastic member to rise and fusing, so that the power transmission between the armature and the hub is performed. Can be shut off. Therefore, a torque limiter function (fuse function) that stops heat generation on the friction surface and shuts off power transmission when overloaded
Can be achieved.

However, in the rubber type, the elastic member also serves to generate a spring force for returning the armature to the direction in which the armature is separated from the rotor friction surface. It is necessary to set the dimension much larger than the leaf spring material, and as a result, there is a problem that the dimension in the clutch axial direction becomes large.

Japanese Utility Model Laid-Open Publication No. 61-194831 discloses that a plate-like elastic member and a rigid plate are arranged on the surface of the armature on the side opposite to the rotor (the side opposite to the friction surface). Elastic member and a rigid plate) are adhered and fixed to each other, and the rigid plate is connected to the inner hub via a plurality of leaf springs, and the vibration sound of the armature is absorbed by the vibration damping action of the plate-like elastic member. An electromagnetic clutch is described that is designed to reduce it.

However, in this prior art, the rigid plate holding one surface of the plate-like elastic member is connected to the inner hub by using a plurality of independent leaf springs, so that the number of parts increases and the product cost increases. There is a problem that becomes.

In view of the above, it is an object of the present invention to provide an electromagnetic clutch having both advantages of a leaf spring type and a rubber type and a simple configuration.

[0011]

To achieve the above object, according to the first aspect of the present invention, the rotating shaft of the driven device (7) is provided on the inner peripheral side of the disc-shaped spring plate member (61). (8)
The driven side connecting portion (61a) connected to the side is integrally formed, and the outer peripheral ring portion (61f) facing the armature (5) is integrally formed on the outer peripheral side of the disc-shaped spring plate member (61). The armature (5) is separated from the driving-side rotating member (4) between the driven-side connecting portion (61a) and the outer peripheral ring portion (61f) of the disc-shaped spring plate member (61). A plurality of leaf spring portions (61b) that generate a spring force in one direction are integrally formed so as to extend in the radial direction, and an elastic member (6) is provided between the armature (5) and the outer ring portion (61f).
It is characterized by direct connection according to 3).

According to this, the elastic member (63) is interposed between the armature (5) and the outer peripheral ring portion (61f) of the spring plate member (61).
The shock when the armature (5) is attracted to the driving side rotating member (4) can be reduced by the vibration damping action of the elastic member (63). Similarly, torsional resonance caused by fluctuations in the driving torque of the driven device (7) can be reduced by the vibration damping effect of the elastic member (63). The vibration damping action of these elastic members (63) can effectively reduce the operating noise of the electromagnetic clutch (1) and the driven device (7).

Moreover, the axial return operation of the armature (5) when the clutch is off can be performed by the spring force of the leaf spring portion (61b), so that the elastic member (63) can return the axial direction of the armature (5). It is not necessary to combine the spring action for Therefore, the shape of the elastic member (63) can be formed in a plate shape along the radial direction of the armature (5) and the spring plate member (61), and the elastic member (6) can be formed.
Since the axial dimension (plate thickness) of 3) can be made much smaller than that of the conventional cylindrical elastic member, the axial dimension can be reduced as compared with the conventional rubber type electromagnetic clutch.

When the locking phenomenon of the driven device (7) occurs for some reason, the elastic member (63) is generated by the heat generated on the friction surface between the driving rotating member (4) and the armature (5). Of the elastic member (63), it is possible to exhibit a torque limiter function. Therefore,
The overload state due to the locking phenomenon of the driven device (7) is released, and the occurrence of troubles such as belt breakage and abnormal temperature rise due to continuous overload state for a long time can be suppressed.

Further, the armature (5) and the outer peripheral ring portion (61f) of the spring plate member (61) are directly connected by an elastic member (63), and the armature (5) is directly supported by the elastic member (63). And a spring plate member (6
1) includes a driven side connecting portion (61a) and a plurality of leaf spring portions (6
1b) and the outer peripheral ring portion (61f) are integrally formed, so that the configuration is significantly simpler than that of Japanese Utility Model Laid-Open No. 61-194831, and assembly can be facilitated.

Further, since the plurality of leaf spring portions (61b) are formed so as to extend in the radial direction of the spring leaf member (61), the plurality of leaf spring portions (61b) are complicatedly arranged in the circumferential direction. Not a flat shape, but a plurality of leaf springs (61b)
Can have a simple chevron shape extending in the radial direction as illustrated in FIG.

Therefore, the elastic member (6
The fixing step of 3) can be easily performed, and the shape of the driven side connecting portion (61a) on the inner peripheral side of the spring plate member (61) can be simplified, so that the forming process of the spring plate member (61) becomes easy. .

As a result, an electromagnetic clutch having both advantages of a leaf spring type and a rubber type can be provided at a low cost with a simple configuration.

Specifically, as in the second aspect of the present invention, a notch that partitions both circumferential sides of a plurality of leaf spring portions (61b) is formed in a disc-shaped spring plate member (61). Groove (6
1c) is formed, and the cutout groove (61c) is preferably formed into a curved shape that connects the groove portions (61d) located on one side in the circumferential direction of the adjacent leaf spring portion (61b).

According to the third aspect of the present invention, an outer peripheral ring portion (61f) is provided at an intermediate portion between the plurality of leaf spring portions (61b).
Has a wide portion (61 g) for enlarging the area of the
1g) is characterized in that at least a part of its inner peripheral side extends inward from the inner peripheral surface of the armature (5).

As a result, the widened portion (61g) located at the intermediate portion between the plurality of leaf spring portions (61b) can increase the area of fixation between the outer peripheral ring portion (61f) and the elastic member (63). The torsional durability of the clutch can be improved.

More specifically, the invention has an inner hub (60) connected to the rotating shaft (8), and the driven side connecting portion (61) is connected to the inner hub (60).
a) may be connected.

The reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

This embodiment shows an example in which the present invention is applied to an electromagnetic clutch mounted on a refrigerant compressor of a refrigeration cycle for vehicle air conditioning. FIG. 1 is a sectional view of the electromagnetic clutch, FIG. 2 is a front view of a hub portion which is a main part thereof, FIG. 3 is a rear view of the hub portion, and FIG. is there.

The electromagnetic clutch 1 includes an electromagnetic coil 3 housed in a stator 2, a rotor (drive-side rotating member) 4 that is driven to rotate by a vehicle engine (not shown), and a rotor 4 that is driven by an electromagnetic force generated by the electromagnetic coil 3. 5 attached to the armature, and a hub connected to the armature 5 and rotating integrally with the armature 5 (driven-side rotating member)
6 is provided.

The hub 6 is a refrigerant compressor (driven device) 7
And transmits rotational power to the refrigerant compressor 7.

The stator 2 is made of a magnetic material such as iron and has a U-shaped cross section. An electromagnetic coil 3 is accommodated in the stator 2, and the electromagnetic coil 3 is electrically insulated in the stator 2 by an insulating resin member such as epoxy. Then, the mold is fixed. The stator 2 is fixed to a housing 10 of the refrigerant compressor 7 via a ring-shaped support member 9.

The rotor 4 has a pulley 4a around which a multi-stage V-belt (not shown) is wound.
It is rotated by the rotational power of the engine transmitted via the belt. The rotor 4 is made of a magnetic material such as iron, and has a U-shaped cross section that accommodates the stator 2 with a small gap therebetween. Further, the rotor 4 has a bearing 11 on the inner periphery thereof, and the bearing 11 allows the rotor 4 to rotate the cylindrical boss portion 10 of the housing 10 of the refrigerant compressor 7.
It is rotatably supported on the outer peripheral surface of a.

The armature 5 is opposed to the friction surface of the rotor 4 with a predetermined minute gap (for example, about 0.5 mm), and is formed of a magnetic material such as iron in a ring shape. As shown in FIG. 3, the armature 5 of the present embodiment has a magnetic shielding groove 5c between the inner ring 5a and the outer ring 5b. The groove 5c is divided into a plurality of parts (four in the illustrated example) in the circumferential direction, and the inner ring part 5a and the outer ring part 5b are integrally connected by a bridge part (connection part) 5d between the groove parts 5c. ing.

Next, the details of the hub 6 will be described.
It has an inner hub 60 formed of a ferrous metal in a cylindrical shape, and a spline fitting portion 60a (FIG. 4) is formed on the inner peripheral surface of the cylindrical portion of the inner hub 60. The rotary shaft 8 is integrally fitted in the rotation direction. In addition, mounting flanges 60b extending radially outward from one axial end (left end in FIG. 1) of the cylindrical portion of the inner hub 60 are integrally formed at three circumferential locations (see FIG. 3). I have.

A driven side connecting portion 61a (FIG. 2) of the inner peripheral portion of the spring plate member 61 is connected to the three mounting flange portions 60b by three rivets 62. The spring plate member 61 is made of an iron-based metal spring material, and its entire shape is formed in a disk shape as shown in FIG.

A ring portion 60c is formed to protrude radially inward from one end (left end in FIG. 1) of the cylindrical portion of the inner hub 60 in the axial direction. As a result, it is fastened and fixed to the tip end surface of the rotating shaft 8. Thereby, the hub 6 can be integrally connected to the rotating shaft 8.

As shown in FIG. 2, the spring plate member 61 is a plate extending in the radial direction between the driven side connecting portion 61a of the inner peripheral portion, more specifically, the connecting portion formed by the rivet 62 and the outer peripheral ring portion 61f. Three spring portions 61b are formed. Therefore, the longitudinal direction of the leaf spring portion 61b is oriented in the radial direction.

In order to form the leaf spring portion 61b, a notch groove 61c for partitioning both sides of the leaf spring portion 61b in the circumferential direction.
Is formed. Here, the notch groove 61c has a curved shape, and has a groove portion 61d located on one side in the circumferential direction of the adjacent leaf spring portion 61b, and an intermediate groove portion 61e connecting the groove portions 61d to each other. A curved shape is formed by being located on the innermost side.

The distal ends of the three leaf spring portions 61b on the outer peripheral side are integrally connected to an outer peripheral ring portion 61f. Accordingly, the spring plate member 61 has a distance from the driven side connecting portion 61a of the inner peripheral portion to the outer peripheral ring portion 61f of the spring plate member 61, which is one.
Are connected as one disk shape.

In this embodiment, the notch 61
The intermediate groove 61e of the armature 5c as shown in FIG.
Notch groove 61c so as to be located further inward than the inner peripheral surface of
The curved shape is set. Thereby, a wide portion 61g for enlarging the area of the outer peripheral ring portion 61f can be formed at an intermediate portion between the three leaf spring portions 61b, and the innermost peripheral portion of the wide portion 61g is formed of the armature 5. It can extend to the inside from the inner peripheral surface.

Next, the spring plate member 61 and the armature 5 have substantially the same outer diameter, and between the spring plate member 61 and the armature 5, there is provided an elastic member 63 for directly connecting them.
Is arranged.

The elastic member 63 is made of a rubber-based elastic material, and has a ring-like plate shape corresponding to the ring shape of the armature 5 as shown in FIGS. The elastic member 63 is integrally bonded (fixed) to both the spring plate member 61 and the armature 5 by a method such as baking adhesion (vulcanization adhesion) in a predetermined mold.

More specifically, the elastic member 63 is provided for the armature 5 with the inner ring 5a and the outer ring 5b.
To the spring plate member 61,
A portion closer to the outer periphery than the notch groove 61c, that is, the outer peripheral ring portion 61f and the wide portion 61g as shown by the fine dot portion in FIG.
The elastic member 63 is baked and adhered only to the part. Therefore,
The inner ring 5 of the armature 5 among the spring plate members 61
The elastic member 6 is provided on the driven side connecting portion 61a and the plate spring portion 61b even if the portion is located on the outer peripheral side from the inner peripheral surface of FIG.
3 is not baked and adhered. This is to prevent the elastic deformation of the leaf spring portion 61b from being hindered by the adhesion of the elastic member 63.

In the baking bonding step, by applying a method such as masking the application of the adhesive to the driven-side connecting portion 61a and the plate spring portion 61b, the driven-side connecting portion 61a and the plate spring portion 61b can be applied. The adhesion of the elastic member 63 can be easily prevented.

As the rubber material used for the elastic member 63, a wide range of the operating environment temperature of the vehicle (from -30 ° C.
Those which exhibit excellent characteristics in terms of torque transmission and torque fluctuation absorption (vibration damping) with respect to 120 ° C) are preferable. Specifically, when chlorinated butyl rubber, acrylonitrile butadiene rubber, ethylene propylene rubber or the like is used Good.

The three holes 61h of the spring plate member 61
Is to insert a pin (not shown) and press it against the armature 5 to hold the armature 5 at a predetermined position in the mold when performing the above-mentioned baking and bonding process.
Similarly, three holes 5e of the armature 5 are inserted into a hole (not shown) and pressed against the spring plate member 61 when the above-mentioned baking process is performed, so that the spring plate member 61 is inserted into the mold. In a predetermined position.

In this embodiment, since the elastic members 63 are provided integrally with thin-film-shaped covering portions 63a and 63b for covering the inner peripheral surface and the outer peripheral surface of the armature 5, respectively.
The thin film-shaped covering portions 63a and 63b can also have the same surface protection function as the surface treatment layer. for that reason,
A surface treatment step for the armature 5 can be eliminated.

Next, the operation of the present embodiment in the above configuration will be described. When the energization of the electromagnetic coil 3 is stopped (when the clutch is off), the armature 5 is rotated by the spring force of the leaf spring portion 61b of the spring leaf member 61. 4 is held at a position separated by a predetermined distance from the friction surface.

Therefore, rotational power from a vehicle engine (not shown) is transmitted only to the rotor 4 via the V-belt, and is not transmitted to the armature 5 and the hub 6. Therefore, only the rotor 4 idles on the bearing 11, and the compressor 7 is stopped.

Now, when the electromagnetic coil 3 is energized, the armature 5 is attracted to the rotor 4 by the electromagnetic force generated by the electromagnetic coil 3 against the spring force of the leaf spring portion 61b of the spring plate member 61, and the armature 5 Is attracted to the rotor 4. Then, the rotation of the rotor 4 is transmitted to the rotation shaft 8 of the refrigerant compressor 7 via the armature 5, the elastic member 63, the spring plate member 61, and the inner hub 60, and the refrigerant compressor 7
Operates.

When the energization of the electromagnetic coil 3 is cut off, the armature 5 returns to the original separated position by the spring force of the leaf spring portion 61b of the spring leaf member 61 due to the disappearance of the electromagnetic force. Returns to the stopped state.

By the way, the armature 5 and the spring plate member 6
Since the elastic member 63 is interposed between the outer peripheral ring portion 61f and the outer peripheral ring portion 61f, the armature 5 is brought into contact with the friction surface of the rotor 4 in the process in which the armature 5 is attracted to the rotor 4 when the clutch is turned on. Shock and vibration at the time of being sucked can be reduced by the vibration damping action of the elastic member 63. Similarly, the torsional resonance caused by the fluctuation of the driving torque of the compressor 7 can be reduced by the vibration damping action of the elastic member 63. Due to the vibration damping action of these elastic members 63, the operating noise of the electromagnetic clutch 1 and the refrigerant compressor 7 can be effectively reduced.

In addition, the armature 5 when the clutch is off
Can be performed by the spring force of the leaf spring portion 61b of the spring plate member 61, so that it is not necessary for the elastic member 63 to also perform the spring action for the axial return operation of the armature 5. Therefore, the shape of the elastic member 63 can be made into a thin plate shape along the radial direction of the armature 5 and the outer peripheral ring portion 61f of the spring plate member 61, and the axial dimension (plate thickness) of the elastic member 63 is, for example, The diameter can be reduced to about 2 mm, which can be significantly reduced as compared with the axial dimension (normally, about 10 mm) of a conventional cylindrical elastic member.

Further, when the locking phenomenon of the compressor 7 occurs for some reason, the hub 6 and the armature 5 connected to the rotating shaft 8 of the compressor 7 cannot rotate, so that the rotor 4 is not connected to the armature 5. It will rotate while sliding. As a result, the friction surface between the rotor 4 and the armature 5 generates heat, and the temperature of the elastic member 63 increases.

When the temperature rises to a fusing temperature determined by the material of the elastic member 63, the elastic member 63 is blown,
The connection state between the armature 5 and the spring plate member 61 is interrupted. Therefore, after this, the armature 5 is still attracted to the rotor 4, the rotor 4 rotates integrally with the armature 5, and the armature 5 and the spring plate 6
1 is interrupted, so that the overload state due to the locking phenomenon of the compressor 7 is released. Therefore, it is possible to suppress the occurrence of troubles such as belt breakage or abnormal temperature rise due to the overload state continuing for a long time.

A plurality of leaf spring portions 61b are formed to extend in the radial direction between the driven side connecting portion 61a of the inner peripheral portion of the spring plate member 61 and the outer peripheral ring portion 61f. For this reason, the wide part 61g which enlarges the area of the outer peripheral ring part 61f can be formed in the intermediate part between the plurality of leaf spring parts 61b.

Thus, the spring plate member 61 and the elastic member 6
3, the bonding strength between the two members 61 and 63 can be increased, and the torsional durability of the clutch can be improved. The torsional durability is such that the maximum torque of the compressor is repeatedly applied and released between the armature 5 and the hub 6 (spring plate member 61) at predetermined time intervals, so that the elastic member 63 is broken and the torque cannot be transmitted. It can be evaluated by the number of times of application of the maximum torque of the compressor until the following condition is satisfied.

(Other Embodiments) In the above embodiment, as shown in FIG. 3, a plurality of arc-shaped magnetic shielding grooves 5c are provided between the inner ring portion 5a and the outer ring portion 5b of the armature 5. Although the armature 5 as a whole is formed as an integral part, the inner ring portion 5 of the armature 5 is used as a structure integrally connected by a bridge portion (connection portion) 5 d between the armature 5.
a and the outer ring portion 5b are formed separately from each other, a magnetic blocking groove 5c is arranged between the inner ring portion 5a and the outer ring portion 5b, and the inner ring portion 5a and the outer ring portion 5b are connected to the elastic member 63. It may be configured to be integrally bonded to the spring plate member 61 via a.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electromagnetic clutch according to one embodiment of the present invention.

FIG. 2 is a front view of a hub in the electromagnetic clutch of FIG.

FIG. 3 is a rear view of the hub of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a front view of the hub, in which a bonding area of the elastic member is indicated by a fine dot portion in FIG. 2;

[Explanation of symbols]

3 ... electromagnetic coil, 4 ... rotor (drive side rotating member), 5 ...
Armature, 6 ... Hub (drive side rotating member), 7 ... Compressor (driven side device), 8 ... Rotating shaft, 60 ... Inner hub,
61: spring plate member, 61a: driven side connecting portion, 61b: leaf spring portion, 61c: cutout groove, 61d: groove portion, 61f ...
Outer ring part, 61g ... wide part.

Claims (4)

[Claims] 1. An electromagnetic coil (3) for generating an electromagnetic force when energized, a drive-side rotating member (4) rotationally driven by a drive source, and an electromagnetic force generated by the electromagnetic coil (3). An armature (5) that is attracted to the rotating member (4) and receives the rotation of the driving-side rotating member (4); and a disk-shaped spring plate connected to the rotating shaft (8) of the driven-side device (7). A driven side connecting portion (61a) connected to the rotating shaft (8) side is integrally formed on an inner peripheral side of the disc-shaped spring plate member (61); An outer peripheral ring portion (61f) facing the armature (5) is integrally formed on an outer peripheral side of the disk-shaped spring plate member (61). The arm is provided between the driven side connecting portion (61a) and the outer peripheral ring portion (61f). A plurality of leaf spring portions (61b) for generating a spring force in a direction of separating the tuture (5) from the driving-side rotating member (4) are integrally formed so as to extend in a radial direction, and the armature (5) The outer peripheral ring portion (61f)
And an electromagnetic clutch (63) directly connected between the first and second members by an elastic member (63). 2. A notch groove (61c) that defines both circumferential sides of the plurality of leaf spring portions (61b) is formed in the disc-shaped spring plate member (61), and the notch groove is formed. (6
2. The electromagnetic clutch according to claim 1, wherein 1c) has a curved shape connecting grooves (61 d) located on one side in the circumferential direction of the adjacent leaf springs (61 b). 3. A wide portion (61g) for enlarging an area of the outer peripheral ring portion (61f) at an intermediate portion between the plurality of leaf spring portions (61b), and the wide portion (61g) includes a wide portion (61g). The electromagnetic clutch according to claim 1, wherein at least a part of a circumferential side extends inward from an inner circumferential surface of the armature. 4. An inner hub (60) connected to the rotating shaft (8), and the driven-side connecting portion (61a) is connected to the inner hub (60). 4. The electromagnetic clutch according to any one of claims 1 to 3.