JPH09126247A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To design in an electromagnetic clutch, a bush rubber having a spring constant in a high twisting direction, and also having a desired axial spring constant, by independently arranging a part for receiving the axial reaction of the bush rubber and a part for receiving the reaction in the twisting direction thereof separately from each other. SOLUTION: A first elastically deformed part 23 for receiving the axial reaction of a bush rubber 6 is arranged between a pin member 5 arranged to be projected from a reverse side surface against the clutch rotor side of an armature 4 and a first angularly cylindrical side wall part 31 of a cup 7 integrally formed on a hub plate 8, and a second elastically deformed part 24 for receiving the reaction in the twisting direction of the bush rubber 6 is arranged around the periphery of the pin member 5 having an angularly annular clearance S between the first elastically deformed part 23 and the inner surface of a second angularly cylindrical side wall part 32. Hereby, the axial reaction of the bush rubber 6 may not be increased even though a spring constant in the twisting direction of the second elastically deformed part 24 is increased.

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, for example, an electromagnetic clutch for connecting and disconnecting a refrigeration cycle refrigerant compressor and an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in an electromagnetic clutch mounted on a vehicle air conditioner, a refrigerant compressor which is a so-called refrigeration cycle device of a car air conditioner, a rubber hub is interposed between an inner hub and an outer hub, This rubber hub is not only for the suction direction (axial direction) of the armature,
Displacement is also possible in the torque transmission direction (twisting direction) to provide the effect of reducing torque fluctuations on the refrigerant compressor side.

However, it is difficult to adequately optimize the spring constant in the torque transmission direction (spring constant in the twisting direction) in order to optimize the physical size of the electromagnetic clutch and the spring constant in the axial direction. However, the effect of reducing the torque fluctuation by the rubber hub cannot be said to be sufficient. Therefore, torque fluctuations increase in the frequency range near the torsional resonance point of the electromagnetic clutch and refrigerant compressor vibration system, and when the resonance range is close to the vehicle resonance point, the synergistic effect increases noise. However, there was a problem that noise was transmitted to the passenger compartment.

Here, a plurality of cups integrally formed on the hub plate are arranged on the side opposite to the friction surface of the armature, and bush rubbers are respectively provided between the cups and the plurality of pins fixed to the armature. In an electromagnetic clutch that is mounted and the inner peripheral side of the hub plate is fixed to the inner hub by rivets, increase the thickness of the bush rubber or increase the rubber hardness of the bush rubber to prevent twisting as described above. I try to avoid the resonance point.

[0005]

However, in the conventional electromagnetic clutch, in order to avoid the torsional resonance point, the spring constant of the bush rubber in the torque transmission direction (spring constant in the torsional direction) is increased. However, the spring constant of the bush rubber in the suction direction (spring constant in the axial direction) also increases at the same time. In this way, if the axial reaction force of the bush rubber becomes high, it becomes difficult for the armature to be attracted to the friction surface of the rotor even if a magnetic force is generated in the electromagnetic coil. The problem arises. Such a problem is a great constraint when designing an electromagnetic clutch including a bush rubber having a high spring constant in the torsion direction.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a spring with a high twisting direction in an electromagnetic clutch by separately and independently providing a portion for bearing an axial reaction force of an elastic member and a portion for bearing a twisting direction reaction force. An object of the present invention is to enable a design to obtain an elastic member having a constant and a desired spring constant in the axial direction.

[0007]

According to the first aspect of the present invention, there are provided a first elastically deformable portion which bears an axial reaction force of the elastic member and a second elastically deformable portion which bears a torsional reaction force. By separately providing them independently, even if the spring constant of the second elastic deformation portion in the torsional direction is increased, it does not affect the axial reaction force of the elastic member, and it is possible to avoid the suction failure of the armature. Become. As a result, in the electromagnetic clutch,
This has the effect of facilitating the design of an elastic member having a high spring constant in the torsional direction and a desired spring constant in the axial direction with a sufficient torque fluctuation reducing effect.
Therefore, it is possible to adequately optimize the spring constant in the torque transmission direction while being restricted by the physical size of the electromagnetic clutch and the spring constant in the axial direction. Since it is possible to design an electromagnetic clutch that can avoid the frequency range in the vicinity from the resonance point of the one equipped with the electromagnetic clutch, the synergistic effect of preventing an increase in noise can be obtained.

According to the second aspect of the invention, the first engaged portion provided on the first elastically deformable portion is the first transmission member of the first transmission member.
Since the second locked portion is locked to the locking portion and the second locked portion is locked to the second locking portion of the second transmission member, the first elastically deformable portion is the first transmission member and the second transmission member. Since a desired spring constant in the axial direction can always be generated between and, it is possible to smoothly perform the suction action to the rotor of the armature connected to the first transmission member and the detachment action from the rotor. The effect is obtained.

According to the third aspect of the present invention, when the electromagnetic coil is energized and the armature is attracted to the rotor by the magnetic force of the electromagnetic coil, the first transmission member connected to the armature has a tubular shape of the second transmission member. By axially displacing with respect to the cup, the first transmission member and the first of the cup
The first elastic deformation part sandwiched between the side wall part and the side wall part elastically deforms. As a result, the rotary power of the rotor is transmitted to the armature and the first transmission member by attracting the armature to the rotor and frictionally engaging the rotor. At this time, when the armature is being sucked, the torque is not yet applied in the torque transmission direction (twisting direction), and the second elastic member
Since there is a predetermined gap between the outer surface of the elastically deformable portion and the inner surface of the second side wall portion of the cup, the suction characteristic of the armature does not deteriorate. Once the suction of the armature to the rotor is completed, torque is applied in the torsional direction, and the second elastic deformation portion of the elastic member comes into contact with the inner surface of the second side wall portion of the cup, so that the second elastic deformation portion moves. The elastic deformation causes a reaction force in the torsional direction in the second elastic deformation portion. Therefore,
Without affecting the axial elasticity of the first elastically deformable portion,
The effect that the reaction force of the second elastic deformation portion in the torsion direction, that is, the elastic member having a high spring constant in the torsion direction can be designed can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

[Structure of Embodiment] FIGS. 1 to 5 show an embodiment of the present invention. FIG. 1 is a view showing a main portion of a bush rubber type electromagnetic clutch, and FIGS. It is a figure showing the whole clutch structure.

The bush rubber type electromagnetic clutch 1 is mounted on a refrigerant compressor as an auxiliary machine incorporated in a refrigerating cycle of a car air conditioner, and if necessary, rotates an internal combustion engine (hereinafter referred to as an engine) as a power source. It is a rotary power transmission device that transmits power to a drive shaft (not shown) of the refrigerant compressor. This electromagnetic clutch 1 is roughly classified into an electromagnetic coil 2,
It is composed of a clutch rotor 3 which is rotated by transmitting the rotational power of the engine, an armature 4 arranged to face the clutch rotor 3, and a hub assembly which will be described later and is drivingly connected to the armature 4.

The electromagnetic coil 2 comprises a resin coil bobbin 11
A well-known coil in which a conductive wire such as a copper wire having an insulating coating is wound around is an exciting coil that generates a magnetic force when energized and demagnetizes when the energization is stopped. The electromagnetic coil 2 is supported by the stator housing 12. The stator housing 12 is made of a magnetic material such as iron or low carbon steel and forms a magnetic circuit (magnetic path) of the electromagnetic coil 2 together with the clutch rotor 3 and the armature 4.

The clutch rotor 3 is made of a magnetic material such as iron or low carbon steel, and has a U-shaped cross section (an inverted U-shaped in FIG. 2) that covers the electromagnetic coil 2 supported by the stator housing 12 from one end side. Is formed in. This clutch rotor 3
Has an annular plate-shaped friction wall 13 on one end side. The surface of the friction wall 13 facing the armature 4 (one end surface)
Is a frictional engagement surface (hereinafter abbreviated as frictional surface) that frictionally engages with the armature 4.

Two magnetic poles are formed near the inner circumference and the outer circumference of the friction wall 13 of the clutch rotor 3 by diverting the magnetic flux flowing in the radial direction of the electromagnetic coil 2 to improve the transmission torque. The annular void 14 is formed almost all around. The clutch rotor 3 is rotatably supported on the outer periphery of a housing (not shown) of the refrigerant compressor via a ball bearing 15 arranged on the inner periphery thereof. A multi-stage V-pulley 16 is fixed to the outer circumference of the clutch rotor 3 by welding or the like. And
The clutch rotor 3 is a rotating body that is rotated by the rotational power of the engine transmitted via a multi-stage V belt (not shown) that is wound around the multi-stage V pulley 16, and a drive-side friction member.

The armature 4 is made of a magnetic material such as iron or low carbon steel, and is formed in an annular plate shape. The armature 4 is arranged so as to face the friction surface of the clutch rotor 3 with an axial gap, and the other end surface is a friction engagement surface (hereinafter abbreviated as friction surface) that frictionally engages with the friction surface of the clutch rotor 3. ing. When the electromagnetic coil 2 is energized, the armature 4 is attracted to and frictionally engaged with the clutch rotor 3 side, whereby the rotation of the clutch rotor 3 is transmitted.

Further, like the clutch rotor 3, in the armature 4, a magnetic pole is formed by circumventing the magnetic flux flowing in the radial direction of the electromagnetic coil 2 to form one annular gap (for improving transmission torque). (Not shown) is formed over substantially the entire circumference. A ring shield 18 sandwiched between the clutch rotor 3 and the ball bearing 15 is provided on the inner peripheral side between the friction surface of the clutch rotor 3 and the friction surface of the armature 4. This ring shield 18 is provided so as to extend in the axial direction from the clutch rotor 3 side to the armature 4 side, and when the clutch rotor 3 rotates, oil, lubricant, etc. scatter and the friction surface of the clutch rotor 3 and the friction of the armature 4 are scattered. It is a sealing member that prevents the surface from adhering.

Next, the hub assembly of this embodiment will be described in detail with reference to FIGS. 1 to 5. The hub assembly of this embodiment includes three pin members 5 fixed to the armature 4, three bush rubbers 6 respectively locked to the pin members 5, and three bush rubbers 6 for accommodating the bush rubbers 6.
It comprises a hub plate 8 having individual cups 7, a boss hub 9 connecting the hub plate 8 and the drive shaft of the refrigerant compressor, and the like. The boss hub 9 has an outer peripheral side fixed to the inner peripheral side of the hub plate 8 by using rivets 10, and an inner peripheral side fixed to the drive shaft of the refrigerant compressor by spline fitting or a key.

The three pin members 5 are the first transmission member of the present invention, and as shown in FIGS. 1, 4 and 5, are made of a metal material such as iron or low carbon steel, and have a substantially cylindrical shape. It is formed in a shape. The three pin members 5 are provided so as to project from the one end surface on the opposite side to the clutch rotor 3 side of the armature 4, and are located at the same circumference of the armature 4 and at equal intervals (for example, the armature 4). Are fixed at intervals of 120 °). Specifically, one end side is projected outward from the one end face of the armature 4 in the axial direction, and the other end portion is caulked to be attached to three cylindrical voids 17 of the armature 4 at equal intervals. ing. The three pin members 5 project in the axial direction (axial direction) of the armature 4, and a rectangular top plate portion 21 as a first locking portion is provided at the tip of the projecting portion.
A cylindrical body portion 22 having an outer diameter smaller than that of the top plate portion 21 is provided on the remaining portion of the protruding portion. That is, the outer peripheral edge of the top plate portion 21 projects like a brim from the outer periphery of the body portion 22. Here, when the body portion 22 and the bush rubber 6 have an adhesive structure, the top plate portion 21 becomes unnecessary.

The three bush rubbers 6 are the elastic members of the present invention, and as shown in FIGS. 1, 4 and 5, for example, chlorinated butyl rubber (IIR) or nitrile rubber excellent in vibration absorption. It is formed in a rectangular tube shape by an elastic body such as synthetic rubber such as (NBR) or natural rubber. The bush rubber 6 has a first elastically deforming portion 23 formed in a substantially square ring shape and a second elastically deforming portion 24 formed in a substantially square tube shape so that these elastically deform independently and independently. It is integrally molded into.

The first elastically deforming portion 23 has a pin member 5 at its tip.
Square annular portion 25 as a first locked portion that is locked to the flange-shaped portion of the top plate portion 21, and pyramidal portion that is a second locked portion that is locked to the inner surface of the cup 7 on the outer periphery. It has 26. The first elastically deforming portion 23 is an axial reaction force applying portion that generates an axial reaction force that disengages the armature 4 from the clutch rotor 3 when the energization of the electromagnetic coil 2 is stopped. The spring constant is set.

The second elastic deformation portion 24 is the first elastic deformation portion 2
The outer diameter of the pin member 5 is smaller than that of the pin 3, and the pin member 5 is attached to the outer periphery of the pin member 5 without adhesion. The second elastically deformable portion 24 has a square annular gap S between its outer surface and the inner surface of the cup 7.
When the torque in the twisting direction is transmitted from the clutch rotor 3 to the armature 4, the second elastic deformation portion 24
It is a twisting direction reaction force applying portion in which a twisting direction reaction force is generated by coming into contact with the inner surface of the cup 7. The second elastic deformation portion 24 is also a portion that absorbs torque fluctuations on the refrigerant compressor side. If the first elastically deformable portion 23 and the second elastically deformable portion 24 are integrally molded, the second elastically deformable portion 2
The inner surface of 4 may be separated from the outer periphery of the pin member 5.

The hub plate 8 is the second transmission member of the present invention. As shown in FIGS. 1, 4 and 5, the hub plate 8 is made of a metal material such as iron or low carbon steel and has three pieces on the outer peripheral side. It has three cups 7 for accommodating the pin member 5 and the three bush rubbers 6. The three cups 7 are formed into a stepped container shape, and have a square tubular first side wall portion 31 with one end open,
A second tubular side wall portion 32 having an inner diameter smaller than that of the first side wall portion 31, a rectangular annular step portion 33 that connects the other end of the first side wall portion 31 and one end of the second side wall portion 32, and 2 is a container-shaped portion including a bottom wall portion 34 that closes the other end of the side wall portion 32.

The first side wall portion 31 is the second locking portion of the present invention. The first side wall portion 31 is the first locking portion when the outer peripheral portion of the pyramidal portion 26 of the first elastic deformation portion 23 is fixed to the inner surface by vulcanization adhesion or the like. This is a portion that houses the elastically deformable portion 23. In addition, it is not always necessary to bond the first elastic deformation portion 23 to the first side wall portion 31.
The second side wall portion 32 is a portion that accommodates the second elastic deformation portion 24 so as to face the inner surface with a square annular gap S therebetween. The bottom wall portion 34 is provided on one end surface of the armature 4 via the bush rubber 6 so that the bottom wall portion 34 can be contacted and separated by the pin member 5.
The central portion has a circular through hole 35 through which the pin member 5 is axially movable.

[Operation of Embodiment] Next, the operation of the electromagnetic clutch 1 of this embodiment will be briefly described with reference to FIGS. 1 to 5.

Due to the magnetic force generated by the energization of the electromagnetic coil 2, the armature 4 has the first bush rubber 6 of three pieces.
The clutch rotor 3 is resisted against the axial reaction force of the elastically deformable portion 23.
Sucked on the side. Here, the three pin members 5 are through holes 3
From the relationship of penetrating 5 so as to be movable in the axial direction, the three pin members 5 together with the armature 4 are displaced toward the clutch rotor 3 side with respect to the three cups 7, so that the three pin members 5 The first elastic deformation portion 23 sandwiched between the flange portion of the top plate portion 21 and the inner surface of the first side wall portion 31 and the inner surface of the step portion 33 of the three cups 7 elastically deforms from the broken line state to the solid line state in the drawing. (Compression deformation) (see FIG. 4).

At this time, when the armature 4 is being attracted to the clutch rotor 3 side, torque is not yet applied in the torque transmission direction (twisting direction), and as shown in FIG. Since the square annular gap S exists between the outer surface of the second elastically deforming portion 24 of No. 6 and the inner surface of the second side wall portions 32 of the three cups 7, the suction characteristic of the armature 4 is not deteriorated.

After that, once the suction of the armature 4 to the clutch rotor 3 is completed and the friction surface of the clutch rotor 3 and the friction surface of the armature 4 are frictionally engaged, the three bush rubbers 6 are twisted. Direction torque is applied, the second elastic deformation portions 24 of the three bush rubbers 6 are compressed by contacting the inner surfaces of the second side wall portions 32 of the three cups 7, and the second elastic deformation portions 24 are elastically deformed. As a result, a torsional reaction force is generated in the second elastic deformation portion 24. As a result, the friction surface of the clutch rotor 3 and the friction surface of the armature 4 are attracted and frictionally engaged with each other, whereby the rotational power of the engine transmitted through the multi-stage V pulley 16 is transmitted through the hub assembly to the refrigerant compressor. Transmitted to the drive shaft of.

When the load torque applied to the drive shaft of the refrigerant compressor fluctuates due to the compression action of the refrigerant, the torque fluctuation is transmitted to the electromagnetic clutch 1 side from the drive shaft. Due to this torque fluctuation, a plurality of bush rubbers 6
Relative rotation (relative angular displacement) occurs between the cup 7 and the pin member 5 due to the elastic deformation of the second elastic deformation portion 24 in the twisting direction.

When the energization of the electromagnetic coil 2 is stopped, the magnetic force generated in the electromagnetic coil 2 is demagnetized, so that the armature 4 attracted to the clutch rotor 3 side has three bush rubbers 6 The first elastically deforming portion 23 is disengaged from the clutch rotor 3 by the axial reaction force and returns to the initial position shown in FIG. As a result, the frictional engagement between the clutch rotor 3 and the armature 4 is released, and the rotational power of the engine transmitted to the clutch rotor 3 is no longer transmitted to the drive shaft of the refrigerant compressor.

[Effects of Embodiment] As described above, in the electromagnetic clutch 1, when the armature 4 is attracted to the clutch rotor 3 side, only the axial reaction force generated by the first elastically deforming portion 23 of the bush rubber 6 is generated. Therefore, even if the spring constant of the bush rubber 6 in the twisting direction is set to be high, the suction failure of the armature 4 can be prevented. That is, the second elastically deformable portion 24 can increase the spring constant in the torsional direction without affecting (increasing) the axial reaction force of the first elastically deformable portion 23. As a result, the electromagnetic clutch 1
In the above, it becomes easy to design the bush rubber 6 having a high spring constant in the torsion direction and a desired spring constant in the axial direction, which has a sufficient torque fluctuation reducing effect.

As a result, the electromagnetic clutch 1 has a sufficiently large spring constant in the torque transmitting direction, even though the size of the electromagnetic clutch 1 is increased and the spring constant in the axial direction is restricted.
Can be designed easily. Therefore, by mounting such an electromagnetic clutch 1 on a Car Ecoan refrigerant compressor, the frequency range near the torsional resonance point of the vibration system of the electromagnetic clutch 1 and the refrigerant compressor, in which the torque fluctuation increases, of the vehicle is increased. By increasing the distance from the resonance point, it is possible to avoid an increase in noise, so that it is possible to reduce noise transmitted to the vehicle interior.

[Modification] In this embodiment, the engine is used as the drive source of the electromagnetic clutch 1, but a drive means such as an electric motor, a wind turbine, or a water turbine may be used as the drive source of the electromagnetic clutch 1. In this embodiment, the present invention is applied to the electromagnetic clutch 1 which connects and disconnects the engine and the refrigerant compressor of the car air conditioner. However, the drive source of the engine and the like, and the follower of the transmission, the supercharger, the pump, the blower, the generator, etc. It may be applied to an electromagnetic clutch that connects and disconnects with the device.

In the present invention, the bush rubber 6
The cup 7 does not have to be in the shape of a square ring or a square tube, and rubber (elastic body) is provided only on the contact side so as to increase the reaction force on the contact side of the first elastic deformation portion 23 and the second elastic deformation portion 24. Or, a shape with an increased amount of rubber (elasticity) to increase the reaction force only on the contact side (for example, star shape, square shape,
A plate shape) is also possible. Further, in the bush rubber 6, the first elastically deforming portion 23 and the second elastically deforming portion 24 may be divided. Instead of the bush rubber 6, an elastic member such as a cushion rubber or a spring may be used.

The second elastic deformation portion (twisting direction reaction force applying portion) 24 does not affect the axial reaction force of the first elastic deformation portion (axial direction reaction force applying portion) 23, for example, The spring constant in the torsional direction can be increased as shown by the broken line portion in FIG. In this case, the inner diameter of the cup 7 also needs to be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an electromagnetic clutch (embodiment).

FIG. 2 is a cross-sectional view showing an overall structure of an electromagnetic clutch (embodiment).

FIG. 3 is a plan view showing the overall structure of an electromagnetic clutch (embodiment).

FIG. 4 is an operation explanatory view showing an elastically deformed state of the bush rubber during suction and immediately after suction (example).

FIG. 5 is an operation explanatory view showing an elastically deformed state of the bush rubber during operation of the refrigerant compressor (Example).

[Explanation of symbols]

 S Square annular gap 1 Electromagnetic clutch 2 Electromagnetic coil 3 Clutch rotor 4 Armature 5 Pin member (first transmission member) 6 Bush rubber (elastic member) 7 Cup 8 Hub plate (second transmission member) 21 Top plate portion (first engagement member) Stop portion 23 first elastic deformation portion 24 second elastic deformation portion 25 square annular portion (first locked portion) 26 pyramidal portion (second locked portion) 31 first side wall portion (second locking portion) ) 32 2nd side wall part 34 Bottom wall part 35 Through hole

Claims (3)

[Claims] 1. An electromagnetic coil for generating a magnetic force when energized, (b) a rotor arranged on the side of the electromagnetic coil, and (c) a rotor facing each other with an axial gap therebetween. And an armature to which the rotation of the rotor is transmitted by being attracted to the rotor by the magnetic force generated by the electromagnetic coil and frictionally engaged with the rotor, and (d) from the side opposite to the rotor side of the armature. The first connected to the armature in a protruding state
A transmission member, (e) provided so as to surround the periphery of the first transmission member,
A second transmission member having a tubular cup extending in the axial direction of the first transmission member; (f) transmitting rotation of the first transmission member to the second transmission member, and A first elastically deformable portion that constantly contacts both the outer surface and the inner surface of the cup and bears an axial reaction force when the armature is sucked in the axial direction, and faces the inner surface of the cup with a predetermined gap. And an elastic member independently provided with a second elastic deforming portion that abuts the inner surface of the cup and receives a reaction force in the twisting direction when the armature is displaced in the twisting direction. Electromagnetic clutch. 2. The electromagnetic clutch according to claim 1, wherein the first transmission member has a first end of the first elastically deformable portion at a tip thereof.
The second transmission member has a first locking portion that locks the locked portion, and the second transmission member has a second elastic deformation portion formed on the inner surface thereof.
An electromagnetic clutch comprising a second locking portion for locking the locked portion. 3. The electromagnetic clutch according to claim 1, wherein the first elastically deformable portion is formed in an annular shape, and the second elastically deformable portion has an outer diameter larger than that of the first elastically deformable portion. Is formed in a tubular shape, and the cup has a cylindrical first side wall portion that is open at one end and accommodates the first elastically deformable portion in a state where the first elastically deformable portion is in contact with the inner surface of the cup. The inner diameter is smaller than that of the first side wall portion, and the second inner surface is opposed to the inner wall with a predetermined gap.
An electromagnetic clutch, comprising: a cylindrical second side wall portion accommodating an elastically deformable portion; and a through hole through which the first transmission member is axially movable.