JP2554076B2 - Electromagnetic clutch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic clutch for connecting and disconnecting power transmission to a supercharger of a vehicle, a refrigerant compressor of an air conditioner, and the like.

[Prior Art] In recent years, a high-class automobile is equipped with a supercharger, that is, a supercharger, and the supercharger is intermittently driven by an electromagnetic clutch when the engine reaches a predetermined rotation speed.

This electromagnetic clutch has a rotor to which an exciting coil is attached and an annular armature, and the armature can be moved toward and away from the rotor. An outer plate having a non-circular, for example, + -shaped flange is attached to the armature, and an inner plate having the same shape as the outer plate is coaxially provided on the outer plate via an elastic member such as cushion rubber. ing. This inner plate is finally connected to the propeller of the supercharger via a drive shaft or the like. When the electromagnetic clutch operates, the armature is attracted to the rotor by energizing the exciting coil, and the rotation of the rotor is transmitted to the propeller through the outer plate, the cushion rubber, the inner plate and the rotating shaft in this order. At this time, the cushion rubber arranged between the inner plate and the outer plate receives a torsional deformation force (shearing force).

[Problems to be Solved by the Invention] Generally, the durability of the cushion rubber against the torsional deformation force is as shown in the graph of FIG. 7. Therefore, in order to improve the durability against the torsional deformation force, The amount of rubber strain when receiving (torsion load) should be reduced. Therefore, if the rubber hardness of the cushion rubber is improved, the spring constant in the torsional direction of the surface of the cushion rubber is increased and the spring constant in the axial direction is also increased. The durability is also improved.

However, the electromagnetic clutch of the vehicle compressor and the refrigerant compressor of the air conditioner has a restriction on the spring constant in the contact / separation direction of the armature (axial direction of the rotating shaft), and if the rubber hardness of the cushion rubber is improved, The spring constant in the axial direction also increases, and there is a risk that the armature will not be sucked, and the cushion rubber could not achieve the desired durability against torsional deformation.

It is an object of the present invention to provide an electromagnetic clutch that dramatically improves the durability of an elastic member against a torsional deformation force without changing the elastic constant of the elastic member in the axial direction.

[Means for Solving Problems] An electromagnetic clutch according to the present invention is provided with an exciting coil that generates a magnetic force when energized, a rotor having an annular plate-shaped friction surface, and a friction surface of the rotor. An armature that is attracted to and frictionally engages the friction surface of the rotor by the magnetic force generated in the exciting coil; and an outer plate that is connected to the armature and that has an outer flange that extends axially away from the armature. An inner plate having an inner flange disposed on the inner peripheral side of the outer flange and facing the outer flange with a predetermined gap, and an axial spring constant for allowing movement of the armature to the rotor side. Is maintained at a predetermined value, and the torsional spring constant for ensuring durability in the torsional direction is set to a predetermined value or more, the outer flange and the A plate member provided in a gap with the side flange and provided in parallel with the outer flange and the inner flange, an outer elastic body that is arranged between the outer flange and the plate member and is elastically deformable, And an elastic member which is disposed between the plate member and the inner flange and is made of an inner elastic body that is elastically deformable.

[Operation] With the above-described configuration, the electromagnetic clutch of the present invention, when transmitting the rotational force on the outer plate or inner plate side to the inner plate or outer plate side via the elastic member, the elastic member exerts a torsional deformation force in the rotational direction. receive. In order to improve the durability of the elastic member against the torsional deformation force, between the flange of the outer plate and the flange of the inner plate,
Since the outer elastic body, the plate member, and the inner elastic body are provided as the elastic members, the lengths of the outer elastic body and the inner elastic body in the twisting direction are shortened, and the outer side elastic member is configured so that the plate member receives the torsional deformation force. It is arranged parallel to the flange of the plate and the flange of the inner plate.

Therefore, in comparison with a conventional elastic member that uses only cushion rubber between the flange of the outer plate and the flange of the inner plate, in the electromagnetic clutch of the present invention, without changing the axial configuration. Since the configuration in the torsion direction is changed, the hardness in the torsion direction of the elastic member can be increased and the elastic constant in the torsion direction can be increased without changing the elastic constant in the axial direction. It is possible to improve durability against force.

Keep the axial spring constant at a predetermined value to allow the armature to move to the rotor side, and make sure that the torsional spring constant for ensuring durability in the torsional direction becomes a predetermined value or more.
Within the scope of the design, various changes can be made regarding the dimensions of the outer elastic body, the inner elastic body, and the plate member.

[Advantages of the Invention] With the above configuration and operation, the electromagnetic clutch of the present invention has the elastic constants in the torsion direction of the outer elastic body and the inner elastic body without changing the elastic constants of the outer elastic body and the inner elastic body in the axial direction. And the durability of the elastic member against the torsional deformation force can be dramatically improved.

Also, keep the axial spring constant at a predetermined value to allow the armature to move toward the rotor side, and set the torsional spring constant to ensure durability in the torsional direction to a predetermined value or more within the design range. The dimensions of the outer elastic body, the inner elastic body and the plate member can be variously changed.

[Embodiment] An electromagnetic clutch of the present invention will be described based on an embodiment shown in the drawings.

1 and 2 show the electromagnetic clutch of the present invention.
This electromagnetic clutch is used to interrupt the transmission of the driving force of the engine to the supercharger of the automobile, that is, the supercharger.

Reference numeral 1 denotes a housing of a supercharger, 2 denotes a stator housing made of a magnetic material, inside of which an exciting coil 3 wound in a cylindrical shape in a plastic winding body 3a is arranged. The winding body 3a is fixed to the stator housing 2 by caulking. The exciting coil 3 is connected to an external power source by lead wires 3b and 3c as shown in FIG. 3, and forms a magnetic circuit as shown by a broken line i in FIG. 2 when energized. .

A mounting flange 2a is joined to the stator housing 2 and is fixed to the supercharger housing 1 by a circlip 4 via the mounting flange 2a.

Reference numeral 5 denotes a rotor having a pulley 6 coupled thereto by welding or the like, which is rotatably mounted on the housing 1 via a bearing 7. An armature 8 is provided so as to face the friction surface 5 a of the rotor 5, and an outer plate 10 is fixed to the armature 8 by a rivet 9. And this outer plate 10
Are connected to the inner plate 12 via elastic members 11.

The outer plate 10 is a flat plate 10a attached to the armature 8, a notch 10c formed in an inner peripheral edge 10b of the flat plate 10a,
And an axially extending outer flange 10d that extends axially away from the armature 8 from its inner peripheral edge 10b. The inner peripheral edge 10b of the flat plate 10a is formed such that the corresponding points are point-symmetric.

The inner plate 12 extends in the axial direction away from the armature 8 from the flat plate 12a disposed inside the flat plate 10a of the outer plate 10 and the outer peripheral edge 12b of the flat plate 12a, and is predetermined inside the outer flange 10d of the outer plate 10. The inner side flanges 12d are formed in a + shape and are arranged to face each other with a gap therebetween.

Outer flange 10d of outer plate 10 and inner plate 12
The elastic member 11 provided between the inner flange 12d and
The cushion rubber 11a is an outer elastic body, the plate member 11b, and the cushion rubber 11c is an inner elastic body.

The plate member 11b is made of carbon steel, and is provided approximately in the middle between the outer flange 10d of the outer plate 10 and the inner flange 12d of the inner plate 12, and the outer flange 10d and the inner flange 1d.
It is arranged parallel to 2d. The longitudinal direction of the plate member 11b is formed longer than the longitudinal direction of the cushion rubber 11c,
The thickness direction of the plate member 11b is formed longer than the thickness direction of the cushion rubbers 11a and 11c. That is, the plate member 11b is
The cushion rubber 11a and the cushion rubber 11c are arranged between them so as not to come into direct contact with each other.

The cushion rubber 11a is filled between the outer flange 10d of the outer plate 10 and the plate member 11b, and the cushion rubber 11a.
c is filled between the plate member 11b and the inner flange 12d of the inner plate 12.

Then, the inner peripheral edge 10b of the outer plate 10 and the inner plate 1
The cushion rubber 11a and the cushion rubber 11c are not provided between the outer peripheral edge 12b and the outer peripheral edge 12b, and holes 50 and holes 51 are formed at four positions at angular intervals of approximately 90 degrees. The hole 51 acts as a relief of the torsional deformation force applied to the cushion rubbers 11a and 11c. However, these holes 51
Is not always necessary, but may be provided as needed.

Here, the outer plate 10 and the inner plate 12 and the elastic member 11 are fixed to each other as follows.

That is, first, an adhesive is applied to the bonding surfaces of the outer plate 10 and the inner plate 12, that is, the inner surface of the outer flange 10d of the outer plate 10, the outer surface of the inner flange 12d of the inner plate 12, and both surfaces of the plate member 11b. Flanged outer flange 10d, inner flange 1
2d and the plate member 11b are arranged in a row with a predetermined gap in between and arranged in the mold. Then, the outer flange 10d in the mold and the plate member 1
1b, between the inner flange 12d and the plate member 11b is filled with unvulcanized rubber, and then the mold is clamped and heated, and the outer plate 10, the plate member 11b, and the inner plate are adhesively bonded. 12 and the cushion rubbers 11a and 11c are adhered, and the cushion rubbers 11a and 11c are molded into a predetermined shape. In this embodiment, the cushion rubbers 11a and 11c
The hole 50 may be formed at the time of filling.

The flat plate 12a of the inner plate 12 is joined and fixed by a hexagonal nut 14 to a rotary shaft 13a connected to a propeller (not shown) of a supercharger via a hub 13 which is integral with the flat plate 12a. In this case, the hub 13 and the rotary shaft 13a are connected by the key 13b. At this time, serrations or splines may be used instead of the keys 13b. The outer plate 10 and the armature 8 are connected to each other by the outer flange 10 of the outer plate 10 as shown in FIG.
It is connected by three rivets 9 provided in d.

 Next, the operation of the electromagnetic clutch of this embodiment will be described.

When the supercharger is activated, when the exciting coil 3 is energized, a magnetic flux is generated as indicated by a broken line i in FIG. 2, and the armature 8 is applied with a force attracted to the rotor 5. As a result, the cushion rubbers 11a and 11c elastically bend, and the armature 8 moves in the axial direction together with the outer plate 10 to be suction-adhered to the friction surface 5a of the rotor 5.

Since the rotor 5 is driven by an automobile engine (not shown) via a pulley 6 and a belt (not shown), when the rotor 5 and the armature 8 are attracted, the driving force is transmitted to the armature 8 and the rotation of the armature 8 Is transmitted to the outer plate 10 via the rivet 9 and further transmitted to the propeller of the supercharger via the cushion rubber 11a, the plate member 11b, the cushion rubber 11c, the inner plate 12, the hub 13 and the rotating shaft 13a in this order.

However, since the supercharger is still stopped at this time, the inner plate 12 is stationary under the force of the load such as the propeller and the moment of inertia. Therefore, the driving force on the driving side received through the outer plate 10 and the force due to the moment of inertia of the inner plate 12 in the stationary state shockly apply to the cushion rubbers 11a and 11c, and a torsional deformation force is applied in the rotation (twisting) direction. Like

Although the torsional deformation force is applied to the cushion rubbers 11a and 11c as described above, the plate member 11b is interposed between the cushion rubbers 11a and 11c.
Since the cushion rubbers 11a and 11c are provided, the length in the torsional direction is shortened. Also, this plate member 11b is the outer plate 1
Since the outer flange 10d of 0 and the inner flange 12d of the inner plate 12 are arranged parallel to each other, the plate member 11b absorbs the twisting deformation force.

Therefore, in comparison with the conventional elastic member using only the cushion rubber between the outer plate and the inner plate, the electromagnetic clutch of the present embodiment does not change the configuration in the axial direction, The configuration of has been changed.

Here, the spring constant of this embodiment is set according to the following equation.

I. Torsional spring constant KN Torsional spring constant kc per unit is kc = Eap · ab / ha: vertical length of rubber b: horizontal length of rubber h: thickness of rubber where apparent elasticity The rate Eap = α · G is given by

∴kc = α ・ G ・ ab / h Torsional spring constant (torque / rad) is kN ＝ T / θ ＝ Fr / θ ＝ Kc ・ rθ ・ r / θ ＝ Kc ・ r ² KN ＝ n ・ α ・ G ・r ² ab / h …… II. Axial spring constant KG The axial spring constant kc per piece is kc = Gap · ab / h where the apparent shear modulus Gap is Gap = G (1 + 1/3・ H ² / a ² ) ^-1 KN = n ・ G ・ ab / h (1 + 1/3 ・ h ² / a ² ) ... n: Number of rubber dampers S: Shape ratio S = ab / {2 (a + b) h }, In the formula, the number of rubber dampers: n ′ = 2n (twice) Rubber damper thickness: h ′ = (h−t) / 2 t: The plate thickness of the plate member 11b, the axial direction of the cushion rubber 11a, 11c The rubber hardness (shear elastic modulus) is changed so as not to change the spring constant.

That is, the electromagnetic clutch of the present embodiment can increase the hardness of the elastic member 11 in the torsional direction and increase the spring constant of the torsional direction without changing the spring constant in the axial direction. The durability against force can be dramatically improved.

In addition, the axial spring constant is maintained at a predetermined value to allow the armature 8 to move toward the rotor 5, and the design is made so that the torsion spring constant for ensuring durability in the torsion direction is equal to or greater than the predetermined value. Within the range, the cushion rubber 11a and the cushion rubber 11c have a vertical length a, a horizontal length b, and a thickness h,
The dimensions of the cushion rubber 11a and the cushion rubber 11c and the plate member 11b such as the plate thickness t of the plate member 11b can be changed.

 4 and 5 show a second embodiment of the present invention.

(Functions having the same functions as those in the first embodiment are designated by the same reference numerals) In this embodiment, the gap between the outer plate 10 and the inner plate 12 is set to gradually widen in the radial direction. For example, the gap A is larger than the gap B as indicated by symbols A and B in FIG. With this setting, when the cushion rubbers 11a and 11c are deformed between the outer plate 10 and the inner plate 12, the amount of deformation is generally uniform, and the outer plate 10 and the inner plate 12 are elastically spaced at equal intervals. Contrary to a large local deformation, the cushion rubbers 11a and 11c do not undergo fatigue deterioration at an early stage and contribute to a longer life such as improved durability.

 FIG. 6 shows a third embodiment of the present invention.

(Functions that are the same as in the first embodiment are given the same numbers) In the case of this embodiment, the points that differ from the above-mentioned embodiments are.
Outer flange 10d of outer plate 10 and inner plate 1
The two inner flanges 12d are both Y-shaped. Even with this structure, the same effect as that of each of the above-described embodiments can be obtained.

In this embodiment, the outer flange 10d of the outer plate 10,
After the inner flange 12d of the inner plate 12 and the plate member 11b are arranged in a row with a predetermined gap, the cushion rubbers 11a and 11c
Although the cushion rubber is filled between the outer flange 10d of the outer plate 10 and the inner flange 12d of the inner plate 12, the plate member 11b may be fitted in the middle of the cushion rubber.

In this embodiment, the inner peripheral edge of the outer plate and the outer peripheral edge of the inner plate are formed in a substantially + shape or a substantially Y shape.
If the inner peripheral edge of the outer plate and the outer peripheral edge of the inner plate are formed in a shape in which the axial center exists at the rotation center of the outer plate and the inner plate, point symmetry, axial symmetry, etc. are not limited to this embodiment.

In addition, in concrete implementation, the application target is not limited to a supercharger of an automobile, but may be applied to a refrigerant compressor of an air conditioner, and various modifications can be made without departing from the gist of the invention.

[Brief description of drawings]

1 is a front view showing the left half of the first embodiment of the electromagnetic clutch of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG.
FIG. 1 is a perspective view showing a first embodiment of an electromagnetic clutch of the present invention,
FIG. 4 is a front view showing the left half of the second embodiment of the present invention, FIG. 5 is a vertical sectional view taken along the line A--A of FIG. 4, and FIG. 6 is a third embodiment of the electromagnetic clutch of the present invention. And FIG. 7 is a graph showing the relationship between the amount of rubber strain and the number of times of endurance with respect to the torsional deformation force. In the figure, 3 ... Excitation coil, 5 ... Rotor, 8 ... Armature, 10 ... Outer plate, 11 ... Elastic member, 12 ...
Inner plate, 10a …… flat plate, 10b …… inner peripheral edge, 10c ……
Notch, 10d …… Outside flange, 11a …… Cushion rubber (outer elastic body), 11b …… Plate member, 11c …… Cushion rubber (inner elastic body), 12a …… Plate, 12b …… Outer peripheral edge, 12d
...... Inner flange

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Tabuchi 1-1, Showamachi, Kariya City, Nippon Denso Co., Ltd. (72) Inventor Yoshiro Kato, Toyota City, Toyota City 1 (72) Inventor Tomoyuki Kurata 1 Kashio-cho, Totsuka-ku, Yokohama-shi Bridgestone Co., Ltd. (56) Bibliography 57-83925 (JP, U) 58-60586 (JP, U)

Claims (1)

(57) [Claims] 1. An exciting coil which generates a magnetic force when energized, a rotor having an annular plate-shaped friction surface, and a rotor which is arranged so as to face the friction surface of the rotor and which is generated by the magnetic force generated in the exciting coil of the rotor. An armature that attracts and frictionally engages a friction surface, an outer plate that is connected to the armature and that has an outer flange that extends axially away from the armature, and an inner peripheral side of the outer flange, and An inner plate having an inner flange opposite to the outer flange with a predetermined gap, and an axial spring constant kept at a predetermined value to allow movement of the armature to the rotor side, and durability in the torsion direction is maintained. It is provided in the gap between the outer flange and the inner flange so that the torsional spring constant for ensuring the spring constant is equal to or greater than a predetermined value. A plate member provided parallel to the outer flange and the inner flange, an outer elastic body that is arranged between the outer flange and the plate member and is elastically deformable, and between the plate member and the inner flange. And an elastic member formed of an inner elastic body that is elastically deformable.