JPS639786Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a coil case for an electromagnetic clutch.

As shown in FIG. 5, the coil case 115 that fixedly supports the magnetic coil 120 of the electromagnetic clutch 101 has a U-shaped cross section in which an inner cylindrical portion 116 and an outer cylindrical portion 117 are continuous at a disk portion 118 at the rear end. Moreover, it was an integrally molded product made by deep drawing a relatively thick yoke by press forming.

Then, the bobbin 121 on which the magnetic coil 120 is wound in advance is placed in the coil case 1 having a U-shaped cross section.
15 and insert it into the front end 116 of the inner cylinder part of the case 115.
The bobbin 121 was fixed in the case 115 by caulking 116b in the outer circumferential direction.

That is, since the conventional coil case 115 is an integrally molded product with a U-shaped cross section by deep drawing,
Even the outer cylindrical portion 117 is thick, and the outer diameter of the outer cylindrical portion is inevitably large.
The front end of the inner cylinder part had to be caulked 116b.

Also, the magnetic coil 120 is attached to the bobbin 121 in advance.
In order to wind the bobbin 121 in layers, it was necessary to give the bobbin 121 a certain degree of wall thickness.

In view of the above points, the present invention was made to improve these problems, and its purpose is to transform the coil case into a yoke (inner case) in which a disk part is formed on the outer periphery of the rear end of the small diameter cylindrical part. and a thin plate yoke (outer case) with a disk portion formed on the inner periphery of the front end of a large diameter cylindrical portion, and the magnetic coil is held between the disk portion of the inner case and the disk portion of the outer case. In this way, the outer periphery of the disc part of the inner case and the inner periphery of the cylindrical part of the outer case are press-fitted, and the outer casing can be made thinner and the outer casing can be made thinner without requiring the conventional press deep drawing of the outer cylindrical part of the case. The coil case can be made smaller and lighter without increasing the diameter, and the crimping process can be omitted, and the magnetic coil can be layered after the bobbin is attached to the inner case, so the coil case can be made smaller and lighter. In particular, by making the outer case and bobbin thinner, it is possible to bring the magnet coil closer to the outer and inner cylinder parts that constitute the annular recess of the rotor, which is the iron core that the magnet coil faces. It has excellent magnetic transmission efficiency,
To provide an inexpensive coil case for an electromagnetic clutch.

A further object of the present invention is to shorten the axial length of the cylindrical portion of the inner case to form a space in front of the cylindrical portion, and to form an inner cylindrical portion forming the annular recess of the rotor in the space. By exposing the large diameter part formed on the outer periphery of the yoke, and by making the cylindrical part of the inner case face the large diameter part in the axial direction, further improvement of magnetic transmission efficiency is planned. To provide an inexpensive coil case for an electromagnetic clutch by eliminating press deep drawing of the coil case.

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 4. FIG. 1 is a longitudinal cross-sectional side view showing a main part of the electromagnetic clutch according to the present invention, partially cut away.

The tip of the casing 2 of the electromagnetic clutch 1 constitutes a small-diameter boss portion 2a, and the shaft 3 projects its tip forward by inserting horizontally into this 2a, and the shaft 3 has a mechanical seal 4 and a bearing (not shown). It is supported by the boss portion 2a via the boss portion 2a. A hub 5 is keyed to the tip of the shaft 3, and a damper plate 6 is integrally connected to the tip surface of the shaft 3.
constitutes a driven plate, and a nut 7 is fastened to the tip of the shaft 3. A stopper rubber 8 is interposed on the rear surface of the damper plate 6, and a disk plate 9 is installed.
is attached, and this 9 is in close proximity to a rotor 10 rotatably provided on the outer periphery of the casing boss portion 2a. Both the disk plate 9 and the rotor 10 have iron cores, and the rotor 10 is mounted immovably in the axial direction on the outer periphery of the boss portion 2a via a ball bearing 11. In the figure, 12 is a nut, 13 is an oil cover, and 14 is a snap ring.

A V-groove 10a is formed on the outer periphery of the rotor 10, and the rotor 10 is connected to a drive source such as an automobile engine through a V-belt (not shown) stretched across the rotor 10a, so that the rotor 10 is constantly rotating. The electromagnetic clutch 1 is connected by energizing a magnet coil (to be described later) facing inside an annular recess 10b provided in the rearward opening, and the rotation is transmitted to the shaft 3, and the compressor etc. are operated.

The coil case according to the present invention is constructed as follows.

The coil case 15 consists of an inner case 16 and an outer case 17. The inner case 16 is a yoke in which a disk part 16b is formed on the outer periphery of the rear end of a small diameter cylindrical part 16a, and the outer case 17 is a yoke that has a large diameter cylindrical part 17a.
This is a thin plate yoke in which a disk portion 17b is formed on the inner periphery of the front end.

As shown in FIG. 2, an annular groove 18 is formed on the outer peripheral surface 16c of the disk portion of the inner case 16, and an annular projection 19 is formed on the rear inner peripheral surface 17c of the outer case 17, so that the groove 18 and the projection 19 are engaged with each other. The coil case 15 is assembled by press-fitting.

A bobbin 21 is attached to the outer periphery of the cylindrical portion 16a of the inner case 16 of the coil case 15, and the magnetic coil 20 is wound around the bobbin 21. After that, the outer case 17 is press-fitted into the inner case 16 as described above, and the magnetic coil 20 is sandwiched between the disc part 16b of the inner case 16 and the disc part 17b of the outer case 17, and the coil case 1 is assembled.
The magnet coil 20 is fixed to the magnet 5. The bobbin 21 is made of molded resin.

In the embodiment shown in FIG. 1, the coil case 1
5 is fixedly supported on the outer periphery of the casing boss portion 2a via the support plate 22, and a U-shaped cross-sectional portion 17d is integrally molded in the outer circumferential direction at the rear end of the outer case 17, but such a configuration is optional. .

Further, the length in the axial direction of the cylindrical portion 16a of the inner case 16 of the coil case 15 is shortened, and a space S is formed in front of the cylindrical portion 16a. The large diameter part 10d formed on the outer periphery of the cylindrical part 10c is brought directly close to the magnet coil 20, and the inner case 1 is placed at the rear end of this 10d.
The front ends of the cylindrical portions 16a of No. 6 are opposed to each other in the axial direction.

Since the coil case 15 is constructed by combining the inner case 16 and the outer case 17, it is possible to eliminate the conventional press deep drawing and crimping processes for the outer cylinder part of the case, thereby making it possible to reduce the thickness of the outer case 17. In addition, the outer diameter of the outer case 17 can be made as small as possible, and thus the coil case 15 can be made smaller and lighter. Furthermore, since the magnetic coil 20 can be wound after the bobbin 21 is attached to the inner case 16, the assembly process is of course improved.
It is also possible to reduce the thickness of the bobbin 21.
Therefore, by making the outer case 17 thinner and the bobbin 21 thinner, the magnetic coil 20 can be brought closer to both the outer cylindrical part 10e and the inner cylindrical part 10c that constitute the annular recess 10b of the rotor 10, which is the iron core. As a result, the magnetic transmission efficiency becomes extremely high, and moreover, the above can be provided at a low price.

Further, the cylindrical portion 16a of the inner case 16 is formed short, and the large diameter portion 10d formed on the outer periphery of the inner cylindrical portion 10c of the rotor 10 is exposed to this shortened space S, so that these 16a and 10d face each other in the axial direction. If so,
The inner cylindrical portion 10c of the rotor 10, which is the iron core, and the magnet coil 20 are brought close to each other, which contributes to further improvement of the magnetic transmission efficiency, and there is no need to deep-draw the inner case 16 at all. Therefore, the number of man-hours for processing and assembling the coil case 15 is further improved, and the cost is further reduced.

Next, we will describe the injection of a resin sealant to fill the gap between the outer periphery of the magnetic coil fixedly supported by the coil case and the inner periphery of the outer cylindrical portion of the coil case, as well as both the positive and negative terminal portions of the magnetic coil.

Conventionally, as shown in FIG. 6, both the positive and negative sides of a magnet coil 140 are inserted through a disk portion 138 of a coil case 135 having a U-shaped cross section and led out to the rear (upper side in FIG. 6) of this 138. Terminal part 1
A resin sealing material 150 is injected into 40a and 140a. After about 6 hours of drying time after injection, the sealing material 150 was injected into the case 135 as shown in FIG. 7, and after that, about 6 hours of drying time was also required. Injection into the case 135 is performed using the bobbin 141.
Appropriate holes 141b are bored in the outer peripheral edge of the front part (upper part in FIG. 7) of the disc frame part 141a, and these holes 14
It was carried out from 1b...

However, as shown in FIG. 3, the rear (upper part in FIG. 3) disk frame portion 41a of the bobbin 41, which is attached and fixed to the coil case 35 whose basic structure is similar to that of the present invention described above, has a notch in the outer circumferential direction. 41b
are formed, and these two notches 41b,
41b is aligned with both the positive and negative terminal portions 40a, 40a of the magnet coil 40.

When the resin sealant 50 is injected from one terminal portion 40a, the sealant 50 flows into the case 35 through the notch 41b, and the bobbin 41
Since the periphery of the front disk frame portion 41c of the outer case 37 is covered by the disk portion 37b of the outer case 37, the other terminal portion 4 does not flow out of the case 35.
0a serves as an air vent hole and fills the inside of the case 35 and both terminal portions 40a, 40a. After that, it is sufficient to dry it for about 6 hours.

Therefore, with the above structure, the injection and drying of the sealing material only need to be performed once each, and the process can be shortened by about 6 hours compared to the conventional method.

By the way, FIG. 4 shows a reference example that has a slightly different structure from the embodiments according to the present invention already described, and if a coil case 55 consisting of an inner case 56 and an outer case 57 is formed as shown in FIG. The following advantages can be exhibited.

That is, the rear end of the outer case 57 is extended 57e further rearward, and the mounting piece 5 is attached to the outer periphery of the rear end of the extended portion 57e.
7f was formed, and the mounting piece 57f was fastened to the casing 2 with bolts 70.

In this way, the mounting piece 57 can be installed integrally with the outer case 57, which is a thin plate yoke, without providing a separate support plate.
Since f is formed, a weight reduction of about 10 to 15% can be achieved in this part. Also, casing boss part 2a
Since there is no need to fit a support plate to the casing 2, the outer periphery of the boss portion 2a can be simplified.
The fluidity of the melt in casting, especially in the casting of the boss portion 2a, is improved, and this also has a great effect on countermeasures against defects such as the occurrence of blowholes in the boss portion 2a. Of course, machining the outer periphery of the boss portion 2a is simple and sufficient.

Although various configurations have been explained above, since the coil case according to the present invention is characterized by being formed by combining, other configurations are not limited to the embodiments and any configuration can be adopted. It is possible.

As is clear from the above description, according to the present invention, the coil case is integrated by press-fitting the outer periphery of the disc part of the inner case and the inner periphery of the cylindrical part of the outer case, which improves workability. Since it is no longer necessary to sandwich the layered magnet coil between the disc part of the inner case and the disc part of the outer case and press and form it by deep drawing, we can provide a small and lightweight coil case for the electromagnetic clutch at a low price. In addition, since the cylindrical portion of the inner case having a short axial length and the large diameter portion formed on the outer periphery of the inner cylindrical portion of the rotor face each other in the axial direction, the inner cylindrical portion of the rotor, which is the iron core, and the magnet The coils are placed in close proximity to each other, and this makes it possible to exhibit various features such as improved magnetic transmission efficiency.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention. FIG. 1 is a longitudinal cross-sectional side view showing the main part of the electromagnetic clutch according to the present invention, and FIG. 2 is a fitting portion of the coil case. 3 is an explanatory sectional view of the coil case portion showing the injection of resin sealant into the coil case and the terminal portion of the magnet coil, and FIG. 4 is a main part showing an example of a modification of the outer case. The side sectional views, FIGS. 5 to 7, show conventional examples. FIG. 5 is a side sectional view of the main part of the conventional electromagnetic clutch, and FIG. FIG. 7, which is similar to the figure, is an explanatory sectional view showing the injection of a sealing material into the coil case. In the drawing, 1 is the electromagnetic clutch, 2 is the casing,
10 is a rotor, 10b is an annular recess, 15, 35,
55 is a coil case, 16, 56 is an inner case, 17, 37, 57 is an outer case, 20, 4
0 is a magnet coil.

Claims (1)

[Scope of utility model registration request] In a coil case that fixedly supports a magnet coil facing into an annular recess of a rotor rotatably provided on the outer periphery of the casing of an electromagnetic clutch, the inner case of the yoke has a disk portion formed on the outer periphery of the rear end of the small diameter cylindrical portion. , consists of an outer case of a thin plate yoke in which a disk part is formed on the inner periphery of the front end of a large diameter cylindrical part, and the outer periphery of the disk part of the inner case and the inner periphery of the cylindrical part of the outer case are press-fitted and wound around a bobbin. The layered magnetic coils are sandwiched and fixedly supported between the disc part of the inner case and the disc part of the outer case, and the axial length of the cylindrical part of the inner case is set to be the same as the axial length of the bobbin. In addition, a large diameter portion is formed on the outer periphery of the inner cylindrical portion constituting the annular recess of the rotor, and the cylindrical portion of the inner case is axially opposed to the large diameter portion. Coil case for electromagnetic clutch.