JPH09329157A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a shock absorbing member, and certainly reduce the adsorption sound of a clutch plate, by providing two layer of a wear resistant member and an elastic member to the shock absorbing member, and projecting the wear resistant member from one frictional surface to the other frictional surface. SOLUTION: When an electromagnetic coil is not energized, a part of the wear resistant member 12 of a shock absorbing member 10 is projected from the frictional surface 7a of a rotor 7. When the electromagnetic coil is energized so as to generate electromagnetic force, a clutch plate 14 is adsorbed to the frictional surface 7a against the elastic force of an origin return spring. At this time, the clutch plate 14 is firstly struck against the wear resistant member 12 of the shock absorbing member 10 and adsorbed to the frictional surface 7a while elastically deforming the elastic member 13, thus the collisional force of the clutch plate 14 can be loosened. Next, a gap (g) between the frictional surfaces 14a, 7a of the clutch plate 14 and the rotor 7 is made to be zero, the clutch plate 14 is integrally connected to the rotor 7, and rotational force from an engine is transmitted to a rotary shaft. When energization to the electromagnetic coil is stopped, attraction applied to the clutch plate 14 is made to be zero, thus the connected condition of the clutch plate 14 and the rotor 7 is canceled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch, and more particularly to an electromagnetic clutch for transmitting a driving force from a driving source to a rotating shaft of a refrigerant compressor.

[0002]

2. Description of the Related Art FIG. 4 is a longitudinal sectional view showing a conventional electromagnetic clutch, and FIG. 5 is an exploded perspective view of the electromagnetic clutch of FIG.

This electromagnetic clutch is rotatably supported by a housing (not shown) of a refrigerant compressor through a bearing 105, and is rotated by a rotational force from an engine, and a rotary shaft of the refrigerant compressor. (Not shown) and has a predetermined gap G on the friction surface 107a of the rotating body 107.
The friction surface 114a of the clutch plate 114 and the friction surface 10a of the rotating body 107
And an electromagnetic coil 108 to be attracted to 7a.

A pulley 111 is fixed to the outer peripheral surface of the rotating body 107, a V-belt (not shown) is wound around the pulley 111, and the rotating body 107 is connected to the crankshaft of the engine via the V-belt.

An annular groove 106 is provided on the friction surface 107a of the rotating body 107. Further, the rotating body 107 has a small-diameter hole 11 that allows the annular groove 106 and the annular space 104 to communicate with each other.
5a and the through hole 115 composed of the large diameter hole 115b,
Is provided.

In the annular groove 106, an annular hub 116 and
An annular cushioning member 110 joined to the hub 116 is housed. The hub 116 has a small diameter hole 115a.
A shaft 117 that is slidably inserted into the shaft is integrally provided.

An annular actuating plate 118, which is attracted to the anti-friction surface 120 opposite to the friction surface 107a of the rotating body 107 when the electromagnetic coil 108 is energized, is housed in the annular space 104. The working plate 118 is provided with the hub 1 via the shaft 117.
16 and is movable in the axial direction integrally with the hub 116 and the cushioning member 110. The working plate 118 has a large diameter hole 1.
The elastic force of the coil spring 119 attached to 15b urges the electromagnetic coil 108. Therefore, the buffer member 110 and the hub 116 are retracted in the annular groove 106.

[0008]

When the electromagnetic coil 108 is not energized, the clutch plate 114 is located at a position separated from the friction surface 107a of the rotor 107 by a predetermined gap G by the elastic force of the origin return spring (not shown). Hold.
Therefore, in this state, the driving force from the engine is not transmitted to the rotary shaft of the refrigerant compressor. Also, the operating plate 118
Is separated from the anti-friction surface 120 by the elastic force of the coil spring 119, the buffer member 110 and the hub 116 are retracted into the annular groove 106, and the contact surface of the buffer member 110 is substantially the same as the friction surface 107a of the rotating body 107. Located on the plane.

When the electromagnetic coil 108 is energized and an electromagnetic force is generated, the operating plate 118 is attracted to the anti-friction surface 120 against the elastic force of the coil spring 119, so that the cushioning member 110 causes the friction surface of the rotating body 107. It projects from 107a to the clutch plate 114 side. At the same time, the clutch plate 114 resists the elastic force of the origin return spring and the friction surface 10 of the rotating body 107.
7a is sucked. At this time, the clutch plate 114 first hits the cushioning member 110 and is attracted to the friction surface 107a of the rotating body 107 by pushing the cushioning member 110 back to its original position. Therefore, the collision noise when the clutch plate 114 is attracted is reduced.

The gap G between the friction surface 114a of the clutch plate 114 and the friction surface 107a of the rotor 107 becomes zero,
When the clutch plate 114 is integrally connected to the rotating body 107, the rotational force from the engine is transmitted to the rotary shaft of the refrigerant compressor.

However, in this electromagnetic clutch, the structure for reducing the suction noise of the clutch plate 114 is complicated as described above, the number of parts is large, and the manufacturing cost of the electromagnetic clutch is high. Spring 1
19 and the like are used, the self-excited vibration of the coil spring 119 due to the vibration from the engine, the rattling sound of the hub 116 when the rotating body 107 vibrates in the radial direction, and the buffer member 110 due to the torque generated at the time of adsorption. However, there is a problem that the dragging phenomenon occurs.

The present invention has been made in view of such circumstances, and its problem is to simplify the structure for reducing the suction noise of the clutch plate to suppress the manufacturing cost of the electromagnetic clutch and to improve the durability of the buffer member. It is an object of the present invention to provide an electromagnetic clutch that can improve the performance and more reliably reduce the suction noise of the clutch plate.

[0013]

In order to solve the above-mentioned problems, an electromagnetic clutch according to a first aspect of the present invention is rotatably supported by a housing, and is rotated by a rotational force from a drive source about a rotation shaft as a rotation center. Which includes a rotating body, a clutch plate connected to the rotating shaft and arranged to face a friction surface of the rotating body, and an electromagnetic coil for attracting the friction surface of the clutch plate to the friction surface of the rotating body. In the clutch, a groove provided on either one of the friction surface of the rotating body or the friction surface of the clutch plate, and a buffer member housed in the groove, wherein the buffer member is at least a wear-resistant member. And an elastic member, and a part or all of the wear-resistant member protrudes from the one friction surface toward the other friction surface.

When the electromagnetic coil is energized and an electromagnetic force is generated, the clutch plate is attracted to the friction surface of the rotating body. At this time, the wear-resistant member of the buffer member first comes into contact with the other friction surface, and the elasticity of the buffer member is reached. The member contracts in the thickness direction, and the friction surface of the clutch plate is attracted to the friction surface of the rotating body. In this way, the collision force of the clutch plate is relieved when it is adsorbed on the friction surface of the rotating body, so that the adsorption noise of the clutch plate is reduced.

When the electromagnetic coil is energized, the frictional surface of the clutch plate and the contact surface of the wear-resistant member of the cushioning member are in close contact with each other due to the electromagnetic force of the electromagnetic coil and the elastic force of the elastic member of the cushioning member. Power is gained.

The electromagnetic clutch of the invention described in claim 2 is
In the electromagnetic clutch of the invention described in claim 1, the groove is an annular groove.

Since the groove is an annular groove, the suction noise of the clutch plate can be reduced by accommodating one annular buffer member in the groove.

An electromagnetic clutch according to a third aspect of the invention is
In the electromagnetic clutch of the invention according to claim 1 or 2,
The wear resistant member is a base material mainly composed of steel fibers and metal powder, a binder of thermosetting resin, and at least one of cashew polymer, calcium carbonate and alumina.
And a friction and wear adjusting agent containing one of them, and the elastic member is made of a rubber or resin material.

By adding a metallic material or a friction and wear modifier as the wear resistant member of the cushioning member, the wear resistance is improved, the life of the cushioning member is extended, and the suction noise of the clutch plate is generated for a long period of time. It can be kept small and a larger frictional force can be obtained.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view showing an electromagnetic clutch according to an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view showing a state where the clutch plate is attracted to a friction surface of a rotating body, and FIG. 3 is a clutch plate. FIG. 4 is a partially enlarged cross-sectional view showing a state in which is not adsorbed on the friction surface of the rotating body.

This electromagnetic clutch is rotatably supported by a boss portion 1a of a housing 1 of the refrigerant compressor via a radial bearing 5, and an engine (driving source) not shown with the rotary shaft 2 of the refrigerant compressor as the center of rotation. The rotating body 7 that is rotated by the rotating force from the rotating body 7 is connected to the rotating shaft 2 through the connecting member 9, and the friction surface 7a of the rotating body 7 is separated by a predetermined gap g (for example, 0.3 to 0.6 mm). The clutch plate 14 is disposed to face each other, and the electromagnetic coil 8 that attracts the friction surface 14 a of the clutch plate 14 to the friction surface 7 a of the rotating body 7.

The electromagnetic coil 8 is the annular space 4 of the rotor 7.
And is fixed to the housing 1 via the connecting fitting 3.

A pulley 11 is fixed to the outer peripheral surface of the rotating body 7, a V belt (not shown) is wound around the pulley 11, and the rotating body 7 is connected to the crankshaft of the engine via the V belt.

An annular groove 6 is provided on the friction surface 7a of the rotating body 7, and a buffer member 10 is housed in the annular groove 6. The rotating body 7 is provided with a plurality of through holes 15 that allow the annular groove 6 and the annular space 4 to communicate with each other. As shown in FIG. 3, the cushioning member 10 includes a wear-resistant member 12 and an elastic member 13.
It is a layered structure. Wear-resistant member 1 when the electromagnetic coil 8 is not energized
A part of 2 is a predetermined amount from the friction surface 7a of the rotating body 7 (for example,
0.2 mm) It projects toward the clutch plate 14 side.

The wear resistant member 12 is a friction wear containing a base material mainly composed of steel fibers and metal powder, a thermosetting resin binder, and at least one of cashew polymer, calcium carbonate and alumina. It is a mixture with a regulator.

The elastic member 13 is made of a rubber or resin material, for example, an organic or inorganic material as a main component and a phenol-modified resin as a binder. In addition to this, the ratio of the rubber-based material in the base material may be increased, and a natural or synthetic rubber-based binder as a main component and an elastic material may be used. Further, a single material may be used as long as it is excellent in elasticity, but there are not many single materials having appropriate elasticity, and in consideration of joining with the wear resistant member 12, the above materials are suitable.

Although the wear resistant member 12 and the elastic member 13 are integrally joined, the joining may be performed by disposing a binder and heat-bonding, or by an adhesive sheet.

The cushioning member 10 is manufactured by the following method.

Weighing step (weighing of base material, friction and wear modifier, binder, etc.), stirring step (dry, semi-wet, wet, etc.), preforming step (molding, extrusion or calendering), preheating step (80 to 120 ° C, 1 to several hours), thermoforming step (130 to 200 ° C, 100 to 20)
0 kg / cm ² , 5 to 30 minutes), heat treatment step (150 to 3)
The cushioning member 10 is manufactured through a polishing process (00 ° C., several hours).

The wear-resistant member 12 and the elastic member 13 are separately manufactured by executing the above-mentioned steps, respectively, and the
13 may be joined, or the wear resistant member 12 may be preformed first, and the elastic member 13 may be preformed later, and then the wear resistant member 12 and the elastic member 13 may be preheated together in the following steps. It may be executed.

Next, the operation of the above electromagnetic clutch will be described.

When the electromagnetic coil 8 is not energized, as shown in FIG. 3, the clutch plate 14 is at a position separated from the friction surface 7a of the rotor 7 by a predetermined gap g by the elastic force of an origin return spring (not shown). Hold. Therefore,
In this state, the driving force from the engine is not transmitted to the rotary shaft 2 of the refrigerant compressor. When the electromagnetic coil 8 is not energized, a part of the wear resistant member 12 of the cushioning member 10 is partially abraded by the friction surface 7 of the rotating body 7.
It projects from a toward the clutch plate 14 side (see FIG. 3).
reference).

When the electromagnetic coil 8 is energized to generate an electromagnetic force, the clutch plate 14 is attracted to the friction surface 7a of the rotating body 7 against the elastic force of the origin return spring (see FIG. 2). When the clutch plate 14 is sucked, the clutch plate 14 first hits the wear-resistant member 12 of the cushioning member 10, and elastically deforms (contracts in the thickness direction) the elastic member 13 of the cushioning member 10 while frictionally contacting the friction surface 7a of the rotating body 7. Is sucked into. Since the collision force of the clutch plate 14 is relieved when it is adsorbed to the friction surface 7a of the rotating body 7 in this way, the adsorption noise of the clutch plate 14 is reduced.

Friction surface 14a of clutch plate 14 and rotor 7
When the gap g from the friction surface 7 a of the clutch plate 14 becomes zero and the clutch plate 14 is integrally connected to the rotating body 7, the rotational force from the engine is transmitted to the rotating shaft 2.

When the supply of electric power to the electromagnetic coil 8 is stopped, the suction force acting on the clutch plate 14 becomes zero, and the elastic force of the origin return spring causes the clutch plate 14 to move to the friction surface 7 of the rotating body 7.
When the clutch plate 14 and the rotating body 7 are separated from a, the coupling state between the clutch plate 14 and the rotating body 7 is released, and the state shown in FIG.

According to the electromagnetic clutch of this embodiment, when the clutch plate 14 is attracted to the friction surface 7a of the rotating body 7, the collision force of the clutch plate 14 is alleviated, so that the attraction noise of the clutch plate 14 is small. Further, since the structure for reducing the suction noise of the clutch plate 14 is simple, the number of parts is reduced and the manufacturing cost of the electromagnetic clutch can be reduced.

In the case of this embodiment, the cushioning member 10 is used.
Since the wear resistance member 12 has a high friction coefficient, the transmission torque is also advantageous, and the electromagnetic clutch can be downsized and power consumption can be reduced. Furthermore, by adding a metallic material as the wear resistant member 12 of the buffer member 10, wear resistance is improved, the life of the buffer member 10 is extended, and the suction noise of the clutch plate 14 is kept low for a long period of time. be able to.

Furthermore, since no coil springs or hubs are used, the self-excited vibration of the springs and the hitting sound caused by the rattling of the hub,
A drag phenomenon or the like due to the generated torque at the time of adsorption does not occur.

In the above embodiment, the cushioning member 10 is used.
The case where the annular groove 6 for accommodating the oil is provided on the friction surface 7a of the rotating body 7 has been described, but instead of this, the annular surface 6 is provided on the friction surface 14a of the clutch plate 14 and the annular groove 6 is buffered. The member 10 may be housed. Even in this case, the same effect as that of the above-described embodiment can be obtained.

In the above-described embodiment, the cushioning member 10 is used.
In the above, the case where the wear resistant member 12 and the elastic member 13 have a two-layer structure has been described, but the cushioning member 10 may have a multilayer structure of three layers or more including two layers of the wear resistant member 12 and the elastic member 13.

Further, in the above-described embodiment, the cushioning member 10 is used.
Although the case where the annular groove 6 is adopted as a groove for accommodating the above is described, instead of this, for example, a plurality of arc-shaped grooves (not shown) are provided along the circumferential direction, and the arc-shaped grooves are provided. Alternatively, an arcuate buffer member (not shown) may be housed in each.

[0043]

As described above, according to the electromagnetic clutch of the invention described in claim 1, when the electromagnetic coil is energized, the clutch plate is attracted to the friction surface of the rotating body. The wear-resistant member of the buffer member hits the other friction surface, the elastic member of the buffer member contracts in the thickness direction, and the friction surface of the clutch plate is attracted to the friction surface of the rotating body. Is alleviated and the suction noise of the clutch plate is reduced.

Further, since the structure for reducing the suction noise of the clutch plate is simple, the number of parts is reduced and the manufacturing cost of the electromagnetic clutch can be reduced.

Further, when the electromagnetic coil is energized, the wear-resistant member of the cushioning member contacts the friction surface and the elastic member of the cushioning member does not directly contact the friction surface, so that the life of the cushioning member is extended and the shock absorbing member extends for a long period of time. The suction noise of the clutch plate can be kept low.

Further, when the electromagnetic coil is energized, the frictional surface of the clutch plate and the contact surface of the wear-resistant member of the cushioning member come into close contact with each other due to the electromagnetic force of the electromagnetic coil and the elastic force of the elastic member of the cushioning member, so that a large friction occurs. The force is obtained, the transmission torque is also advantageous, and it is possible to reduce the size of the electromagnetic clutch and save power.

According to the electromagnetic clutch of the second aspect of the invention, since the groove is an annular groove, the suction noise of the clutch plate can be reduced by accommodating one annular buffer member in the groove. .

According to the electromagnetic clutch of the third aspect of the present invention, the wear resistance is improved and the life of the buffer member is improved by adding a metallic material or a friction / wear modifier as the wear resistant member of the buffer member. As a result, the suction noise of the clutch plate can be kept low over a long period of time, and a greater frictional force can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an electromagnetic clutch according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing a state in which a clutch plate is attracted to a friction surface of a rotating body.

FIG. 3 is a partially enlarged sectional view showing a state where a clutch plate is not adsorbed on a friction surface of a rotating body.

FIG. 4 is a vertical sectional view showing a conventional electromagnetic clutch.

5 is an exploded perspective view of the electromagnetic clutch of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 6 Annular groove 7 Rotating body 7a Friction surface of rotating body 8 Electromagnetic coil 10 Cushioning member 12 Abrasion resistant member 13 Elastic member 14 Clutch plate 14a Friction surface of clutch plate

Claims (3)

[Claims] 1. A rotating body which is rotatably supported by a housing and which is rotated by a rotational force from a drive source about a rotating shaft as a center of rotation; and a rotating body which is connected to the rotating shaft and faces a friction surface of the rotating body. An electromagnetic clutch comprising a clutch plate and an electromagnetic coil for adsorbing a friction surface of the clutch plate to a friction surface of the rotating body, wherein a friction surface of either the friction surface of the rotating body or the friction surface of the clutch plate. And a buffer member housed in the groove, wherein the buffer member is at least a wear resistant member and an elastic member.
An electromagnetic clutch comprising a layer, wherein a part or all of the wear resistant member projects from the one friction surface toward the other friction surface. 2. The electromagnetic clutch according to claim 1, wherein the groove is an annular groove. 3. The friction-resistant member comprises a base material mainly composed of steel fibers and metal powder, a binder of thermosetting resin, and at least one of cashew polymer, calcium carbonate and alumina. The electromagnetic clutch according to claim 1 or 2, wherein the elastic member is made of a rubber or resin material and is mixed with a wear modifier.