JP2780377B2 - Electromagnetic coupling device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic coupling device such as an electromagnetic clutch for intermittently transmitting power to a compressor of a vehicle air conditioner.

[Prior Art] Conventionally, as an electromagnetic clutch provided in a compressor of a vehicle air conditioner, for example, there is an electromagnetic clutch shown in FIG. 8 and FIG. This is because a rotor 1 rotates by receiving a rotational force, an armature 2 is disposed opposite to the rotor 1 so as to be able to contact and separate from the rotor 1, and an exciting coil that attracts the armature 2 to the rotor 1 when energized. 3, a cylindrical holding plate 4 that rotates integrally with the armature 2, and an outer peripheral surface 6a that is provided on the inner peripheral side of the holding plate 4 and that is connected to the rotating shaft 5 and faces the holding plate 4. And a cushion rubber (elastic member) 7 interposed between the holding plate 4 of the hub 6 and buffering the rotation of the holding plate 4 to the hub 6.

The cushion rubber 7 is attached by filling an unvulcanized rubber between the outer peripheral surface 6a of the hub 6 coated with the adhesive and the inner peripheral surface 4a of the holding plate 4, and then joining by pressing the mold and heating. . Further, thereafter, the holding plate 4 is drawn from the state shown by the dashed line in FIG.
Is reduced from L1 to L2 to give the cushion rubber 7 a compressive strain. That is, when the cushion rubber 7 is cooled, the heat shrinkage of the holding plate 4 and the hub 6 is smaller than the heat shrinkage of the cushion rubber 7, and the rigidity of the holding plate 4 and the hub 6 is extremely high. 7, a tensile stress is generated. In addition to removing the tensile stress, the tensile stress generated inside the cushion rubber 7 due to torque transmission during use of the electromagnetic clutch is reduced to improve durability. This is generally called “aperture”, and the degree is represented by “aperture ratio” (= (L1−L2) / B), and the optimal value is 10 to 20%. And
The holding plate 4 that has been drawn is fixed to the armature 2 with rivets 8, and the hub 6 is fixed to the rotating shaft 5 with nuts 9.

[Problems to be Solved by the Invention] However, since the holding plate 4 is drawn to impart compressive strain to the cushion rubber 7, it is held by a material which is easily plastically processed such as a low carbon steel plate or an aluminum plate. Even if the plate 4 is formed, an expensive drawing die
A press machine is required, which causes high costs. Also, during the plastic working, the armature holding surface 4b of the holding plate 4 is deformed or displaced from the center of the shaft. Therefore, after performing the plastic working, the finish processing of the armature holding surface 4b and the processing of the rivet hole 4c are performed. And that was also the cause of high costs.

An object of the present invention is to provide an electromagnetic coupling device that can apply compressive strain to an elastic member without plastically deforming a holding plate.

Means for Solving the Problems According to the present invention, there is provided a rotor which rotates by receiving a rotational force, an armature which is provided opposite to the rotor so as to be able to contact and separate from the rotor, and an armature which is energized. An excitation coil for attracting to the rotor, a holding plate that rotates integrally with the armature, and an outer peripheral surface that is provided on the inner peripheral side of the holding plate and that is connected to a rotating shaft and faces the holding plate. And an elastic member interposed between the hub and the holding plate and transmitting the rotation of the holding plate to the hub in a cushioning manner, wherein the elastic member is joined and arranged between the hub and the holding plate. When the hub is attached to the rotating shaft and the holding plate is attached to the armature after the mounting, the electromagnetic coupling device in which the hub and the holding plate are fixed while pressing the elastic member so as to reduce the distance between the hub and the holding plate. The is to its gist.

[Operation] A state in which the elastic member is pressed to reduce the distance between the hub and the holding plate when the hub is attached to the rotating shaft and the holding plate is attached to the armature after the elastic member is joined and arranged between the hub and the holding plate. The elastic member is compressed and deformed by fixing the hub and the holding plate.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 (section AA in FIG. 1) show an electromagnetic clutch in a vehicle air conditioner. A rotary shaft 12 of the compressor is provided in a housing 11 of the compressor. The exciting coil 14 is formed by winding a coil around a plastic cylindrical winding body 14a, and the winding body 14a is fixed to the stator housing 13 by caulking. The exciting coil 14 is connected to an external power supply by a lead wire (not shown), and when energized, forms a magnetic circuit as shown by a one-dot chain line (a) in FIG.

A mounting flange 13a is joined to the stator housing 13, and is fixed to the compressor housing 11 by a circlip 15 via the mounting flange 13a. The rotor 16 made of a magnetic material is formed integrally with the pulley, and is rotatably mounted on the housing 11 of the compressor via a bearing 17. The ring shield 18 is fixed by a rotor 16 and a bearing 17.

As shown in FIG. 3, the armature 19 made of a magnetic material has a disk shape, and three sets of rivet holes 19a are formed for each two armatures. Here, the distance between the center of the armature 19 and each set of rivet holes 19a is L2. The armature 19 is provided facing the sliding surface 16a of the rotor 16, and three holding plates 20 are fixed to the armature 19 by rivets 21. As shown in FIG. 1, the holding plate 20 has an outer peripheral shape that matches the outer peripheral shape of the armature 19, an inner shape that has an arc shape opposite to the outer peripheral shape, and extends in the rotation axis direction. It has an inner wall 20a. Each armature 19 is provided at an even position with respect to the rotating shaft 12.

The hub 23 has a triangular shape having an outer peripheral surface having a side facing the inner wall 20a of the holding plate 20, and a cylindrical portion extending in the rotation axis direction.
23a. The cylindrical portion of the inner wall 20a of the holding plate 20 and the hub 23
A cushion rubber 22 as an elastic member made of butyl rubber or natural rubber is adhered and fixed between the cushion rubber 22a and the cushion rubber 22a.

Here, the holding plate 20 and the hub 23 are fixed to the cushion rubber 22 as follows.

First, as shown in FIGS. 4 and 5, an adhesive is applied to the adhesive surface between the holding plate 20 and the hub 23, that is, the inner surface of the inner wall 20a of the holding plate 20 and the outer surface of the cylindrical portion 23a of the hub 23. The holding plate 20 coated with the adhesive is separated by a predetermined distance, that is, the center of the rivet hole 20b provided in the holding plate 20 is positioned at the position of the distance L1 (> L2) shown in FIG. To load.
Next, the unvulcanized rubber is filled between the holding plate 20 and the hub 23 in the mold, then the mold is squeezed and heated, and the holding plate 20 and the cushion rubber 22, and the hub 23 and the cushion Rubber
Glue to 22.

Then, as shown in FIG.
19, and the rivet hole 20b of the holding plate 20 is set in the armature 1
The cushion rubber 22 is joined by the rivet 21 in a state where the cushion rubber 22 is compressed and deformed until it coincides with the rivet hole 19a of the ninth. As a result, the holding plate 20 is fixed as shown by the chain line in FIG.

At this time, the squeezing rate α of the cushion rubber 22 is α = {(L1−L2) / B} × 100 <%> where B is given by the rubber width before compression deformation, and α = 10 to 20% L1 and L2 are set as described above.

In the case of this embodiment, as shown in FIG. 4, the rubber width B is B1 or B2 depending on the location. Then, the compression deformation rate α1 in the B1 part is 20%, and the compression rate α2 in the B2 part is 10%.
%.

The hub 23 is joined and fixed to the rotating shaft 12 of the compressor by a nut 24.

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

When a DC current is applied to the exciting coil 14 at the time of starting the compressor, magnetic flux is generated as shown by a dashed line (a) in FIG.
A force that is attracted to the rotor 16 is applied to the armature 19, and the cushion rubber 22 bends, so that the armature 19 moves in the axial direction together with the holding plate 20, and the sliding surface 16 of the rotor 16 moves.
Apply suction to a.

Since the rotor 16 is driven by a vehicle engine (not shown) via a belt, when the rotor 16 and the armature 19 are attracted, the driving force is transmitted to the armature 19, and the rotation of the armature 19 is performed via the rivet 21. It is transmitted to the holding plate 20 and further transmitted to the cushion rubber 22. However, at this time, since the compressor is still stationary, the hub 23 is stationary by receiving the load of the piston and the like (not shown) of the compressor and the force due to the moment of inertia. Therefore, the driving force on the driving side received via the holding plate 20 and the force due to the inertia moment of the hub 23 in the stationary state are the cushion rubber.
22 will be twisted in the direction of rotation. And, while this cushion rubber 22 is deformed, the hub
The torque is transmitted to 23.

In addition, during the continuous operation of the compressor, the cushion rubber 22 continuously transmits the driving force, and elastically deforms in response to the fluctuation of the driving torque of the compressor to transmit the rotational force in a buffered manner.
Thereby, protection of the compressor and reduction of noise are achieved.

When the power transmission by the electromagnetic clutch is to be cut off, the power supply to the exciting coil 14 is cut off, and the armature is turned off.
19 is the sliding surface of the rotor 16 due to the restoring force of the cushion rubber 22
It returns to its original position with a predetermined gap from 16a.

From such usage, the cushion rubber 22 is deformed by the size of the suction gap G in the rotation axis direction, that is, in a state of being tensilely deformed, the rotational force at the time of starting the compressor and the continuous driving torque of the compressor. , And undergoes elastic deformation. Rubber materials generally have the property of being strong in compression but weak in tension, and are extremely strictly used. In addition, cushion rubber
Since the molding of 22 and the bonding with the holding plate 20 and the hub 23 are performed by heating, in the completed state of the product, that is, in the use state, the holding plate 20, the holding plate 20,
Since the rigidity of the hub 23 is extremely high, a tensile stress is generated inside the cushion rubber 22.

However, when the hub 23 and the holding plate 20 are attached, the hub 23
In order to reduce the distance between the cushion rubber 22 and the holding plate 20, the cushion rubber 22 is fixed in a state where the cushion rubber 22 is pressed and is subjected to a compressive strain, so that the tensile stress generated inside the cushion rubber 22 is reduced in advance to improve durability. I have it.

Thus, in the present embodiment, in order to reduce the tensile stress generated inside the cushion rubber 22 and improve the durability,
Cushion rubber 22 (elastic member) between hub 23 and holding plate 20
When the hub 23 is attached to the rotating shaft 12 and the holding plate 20 is attached to the armature 19 after the hub 23 is joined to the armature 19, the holding plate 20 is pressed with the cushion rubber 22 pressed to reduce the distance between the hub 23 and the holding plate 20. Fixed. That is, the rivet hole 19a of the armature 19 and the rivet hole 20b of the holding plate 20 are aligned with the cushion rubber 22 pressed, so that the holding plate 20 is fixed to the armature 19. As a result, the molding of the cushion rubber 22
It is not necessary to draw the holding plate 20 after bonding. Therefore, there is no restriction on the material of the holding plate 20, and the holding plate 20 can be used for a material having higher strength, and the weight can be reduced. In addition, there is no problem such as deformation and misalignment of the armature holding surface 20c of the holding plate 20, there is no need to process the armature holding surface 20c, and the rivet holes 20b may be machined in the state of the holding plate 20 alone. Cost can be reduced.

Further, this "aperture" was relatively easy when the holding plate 4 was cylindrical, as shown in FIGS. 8 and 9, but when the holding plate 20 was non-cylindrical or when the holding plate 20 was non-cylindrical. If the inner wall has a slope, it is difficult to manufacture, and the shape of the rubber hub is restricted. However, it is possible to eliminate the restriction of "aperture" and manufacture rubber hubs of various shapes.

The present invention is not limited to the above-described embodiment. For example, as shown in FIGS. 6 and 7 (a sectional view taken along the line BB in FIG. 6), the inner wall 20a of the holding plate 20 is inclined. You may.

In the above embodiment, the armature 19 and the holding plate 20
Is fixed by two rivets 21, but may be fixed by bolts or the like. Further, the positioning between the armature 19 and the holding plate 20 may be performed by, for example, a combination of a projection formed by a pin or a punch and a hole. Although the number of the holding plates 20 has been described as three, two or four as needed.
More than one is acceptable.

In the above embodiment, the holding plate 20 is divided into three types and the mounting position is adjusted. However, the armature side may be divided and the mounting position may be adjusted. In short, hub 23
After the cushion rubber 22 (elastic member) has been joined and disposed between the and the holding plate 20, the cushion rubber 22 is pressed by reducing the relative distance between the hub 23 and the holding plate 20 when the hub 23 and the holding plate 20 are attached. What is necessary is just to be able to fix in a state.

[Effects of the Invention] As described above in detail, according to the present invention, an excellent effect of giving a compressive strain to an elastic member without plastically deforming the holding plate is exhibited.

[Brief description of the drawings]

FIG. 1 is a front view of an electromagnetic clutch according to an embodiment, and FIG.
3 is a front view of the armature, FIG.
Fig. 5 is a diagram for explaining the attachment of the cushion rubber, Fig. 5 is a diagram for explaining the attachment of the cushion rubber, Fig. 6 is a cross-sectional view of another example, and Fig. 7 is a BB cross section of Fig. 6. FIG. 8 is a front view of a conventional electromagnetic clutch, and FIG. 9 is a sectional view of the conventional electromagnetic clutch. 12 is a rotating shaft, 14 is an exciting coil, 16 is a rotor, 19 is an armature, 20 is a holding plate, 22 is a cushion rubber as an elastic member, and 23 is a hub.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16D 27/112

Claims (1)

(57) [Claims] 1. A rotor that rotates by receiving a rotational force, an armature that is disposed opposite to the rotor so as to be able to contact and separate from the rotor, and an excitation coil that attracts the armature to the rotor when energized. A holding plate that rotates integrally with the armature, a hub provided on the inner peripheral side of the holding plate, connected to a rotating shaft, and having an outer peripheral surface facing the holding plate; An elastic member interposed between the holding plates, the elastic member transmitting the rotation of the holding plate to the hub in a buffered manner, to the rotation axis of the hub after the elastic member is joined and arranged between the hub and the holding plate. An electromagnetic coupling device, wherein the hub and the holding plate are fixed in a state where the elastic member is pressed so as to reduce the distance between the hub and the holding plate when the mounting is performed and the holding plate is mounted on the armature.