JPH02275122A - Exciting device for electromagnetic clutch - Google Patents

Abstract

PURPOSE:To improve reliability, and still to intend automatic assembly by setting the opening portion of a bobbin in an axial direction, fitting projected portions integrally arranged on the inner and the outer peripheries thereof to circular grooves of a york main member, and arranging an exciting coil with the york main member in optimum position and in stable state. CONSTITUTION:A york main member 13 is integrally formed in a circular form of U-letter shape with an inner and an outer side flanges 13a, 13b and a bottom plate part 13c, and circular grooves 13d, 13e are providing on the inner and the outer flange parts 13a, 13b at positions facing to projected parts 15j formed on a bobbin 15. Still, the bobbin 15 is formed in U-letter shaped in section by means of an inner and an outer flange parts 15a, 15c having projected parts 15j arranged with a slit in a back face and a bottom plate part 15b, and formed in a circular shape having a butting portion 15f. It can be done thereby that circular groove 13d and the projected parts 15j are fitted to each other, so as to prevent bad insulation between an exciting coil 11 and the york main member 13, and they can be arranged in the optimum position in stable state, and together with improvement of reliability, they can be automatically assembled together.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an excitation device for an electromagnetic clutch, and particularly to an improvement of a bobbin that holds an excitation coil.

[Conventional technology]

The excitation device for the conventional electromagnetic clutch was developed in 1986-395.
As described in Publication No. 40, the cross section approximately U opened in the radial direction.
After winding an excitation coil around a bobbin molded with resin in a circular shape and storing it in the main yoke member, a resin insulator is injected between the excitation coil main yoke members and hardened. The excitation coil wound around the bobbin was insulated and fixed to the main yoke member. However, in such conventional technology, although the side surface and inner circumferential surface of the excitation coil are reliably insulated by the bobbin, due to variations in the outer flange dimensions of the main yoke member and the winding work, the inner surface of the outer flange and the bobbin may be insulated. The outer circumferential surface of the excitation coil wound on the yoke may come into contact with each other, causing insulation failure, and there is no positioning means that allows the excitation coil to be placed in the optimal position within the main yoke member, resulting in an unstable condition. There was a lack of sufficient consideration given that there was a potential for resin molding.

[Problem to be solved by the invention]

In the above conventional technology, sufficient consideration is not given to the fact that the distance between the outer circumferential surface of the excitation coil and the inner circumferential surface of the outer flange of the main yoke member is not constant, and in some cases, the two may come into contact with each other. There was a latent problem that insulation failure occurred at this contact portion.

An object of the present invention is to provide a highly reliable excitation device for an electromagnetic clutch in which an excitation coil is stably arranged at an optimal position on the main yoke member, and no insulation failure occurs. Furthermore, it is an object of the present invention to provide an excitation device that suppresses winding distortion of an excitation coil and is suitable for automatic assembly.

[Means to solve the problem]

The above objective is achieved by making the bobbin cross-section approximately U-shaped with an opening in the same direction as the opening of the main yoke member, and by interposing the bobbin between the excitation coil and the inner surface of the outer flange of the main yoke member. . Further, in order to arrange the excitation coil at an optimal position, protrusions are provided on the inner and outer peripheries of the bobbin, and an annular groove is provided at a position facing the main yoke member, so that the bobbin is housed within the main yoke member. At this time, the protrusion of the bobbin is fitted into the annular groove.

[Effect]

The approximately U-shaped annular bobbin whose cross section opens in the same direction as the opening of the yoke main member is stored in the yoke main member while holding the excitation coil, so that the outer peripheral surface of the excitation coil and the yoke main member are A bobbin, which is an insulator, is interposed between the inner surface of the outer flange and the inner surface of the outer flange. As a result, the outer circumferential surface of the excitation coil and the inner surface of the outer flange of the main yoke member are reliably separated from each other, and unwinding of the excitation coil is suppressed, so that they do not come into contact with each other and cause insulation failure. At the same time, the protrusions provided on the inner and outer peripheries of the bobbin are housed in a fitted state in the annular grooves provided at opposing positions of the main yoke member. As a result, the excitation coil held by the bobbin can be placed at an optimal position within the main yoke member in a stable state with no winding misalignment.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a longitudinal cross-sectional view of an electromagnetic clutch using the present invention, which consists of a hub 3 connected to the shaft end of a shaft 2 of a rotating machine 1, a part of which is shown, and a magnetic material connected to a drive source by a level belt. an input rotating body 8; a movable piece 5 made of a magnetic material disposed at a position opposite to the input rotating body 8 in the axial direction;
An output rotary body 6 comprising a leaf spring 4 for coupling the movable piece 5 to the hub 3, and an excitation device 10 for frictionally engaging the movable piece 5 and the input rotary body 8. There is.

When the excitation coil 11 installed in the excitation device 10 is energized, a main magnetic circuit A as shown by the broken line in FIG. 1 is formed, and the magnetic flux flowing through the main magnetic circuit A causes the movable piece 5 to The driving force of the input rotary body 8 is transmitted to the output rotary body 6 by the frictional engagement force. Further, when the excitation coil 11 is not energized, the spring force of the plate spring 4 separates the movable piece 5 from the input rotary body 8, thereby cutting off the driving force from the input rotary body 8.

Next, the configuration of the excitation device 1o will be described. 13 is a main yoke member, which includes an outer flange portion 13a and an inner flange portion 1.
3b and a bottomed part 13c connecting both flange parts, an electromagnetic steel plate is integrally formed by pressing into an annular cross-sectional shape. Note that the bottom plate portion 13c is provided with a take-out hole for pulling out the lead wire 20 connected to the end of the excitation coil 11 to the outside via the grommet 21. Also 13
d indicates the inner and outer flange portions 13a of the main yoke member 13;

13b are annular grooves provided at positions facing protrusions 15j of the bobbin 15, which will be described later. Furthermore, the inner and outer flange parts 13a and 13b of the main yoke member have a shape that is easy to press by making the wall thickness at the bottom part where a lot of magnetic flux flows thicker to reduce magnetic resistance, and by making the tip part where there is less magnetic flux thinner. I have to. 14 is a support member, which connects the excitation device 1 to the rotating machine 1.
0, and is joined to the back surface of the bottomed part 13c of the main yoke member 13 by caulking, welding, etc.

Next, 15 shown in Fig. 3 is a bobbin, as shown in Fig. 2.
It is continuously molded from a resin such as nylon into an annular shape having a substantially U-shaped cross section, consisting of an outer flange part 15a, an inner flange part 15c, and a bottomed part 15b connecting these two flange parts in a staggered arrangement. It is constructed into an annular shape with an abutting portion 15f as shown in FIG. Furthermore, the inner and outer flange portions 15a and 15c of the bobbin 15 have protruding portions 15j integrally formed on their outer peripheries. Here, a slit 15h is arranged on the back surface of the protrusion 15j in consideration of workability when fitting the protrusion 15j into the annular groove 13d provided in the main yoke member 13. Furthermore, the inner and outer flange portions 15
By arranging a and 15c in a staggered manner, the flange portion 1
5a and 15c are easy to open, and the work of holding the fully wound excitation coil 11 is easy. In addition, 15e provided at the tips of the inner and outer flange portions 15a and 15c are provided to hold down the excitation coil 11 so that it does not move in the axial direction. Next, the excitation coil 11 is held in the U-shaped section of the bobbin 15, and the excitation coil 11 is placed on the back side of the bottomed part 15b.
A lead wire 20a with a grommet 21 attached thereto.

20b are connected using the connector 16 to complete the excitation coil assembly 12 shown in FIG.

Next, FIG. 4 shows a state in which the excitation coil assembly 12 is started to be assembled to the yoke main member 13, and FIG. 5 shows that the protrusion 15j provided on the bobbin 15 of the excitation coil assembly 12 It is in contact with the tips of the inner and outer flanges 13a and 13b of the main iron member 13 and is bent by the back slit 15h. By being further pushed into this successor iron main member 13, the inner and outer flange portions 13 of the iron yoke main member 13
a.

The protrusion 15j is fitted into an annular groove 13d provided on the inner periphery of the excitation coil assembly 13b, thereby fixing the excitation coil assembly 12 in the axial direction.

Thereafter, after injecting the insulating resin 18 between the yoke main member 13 and the exciting coil assembly 12 in the same manner as in the prior art,
After a hardening process, the excitation device 10 of the present invention is completed.

Incidentally, FIG. 7 shows a bobbin according to another embodiment.

By using a plurality of winding excitation coils 11 instead of the bobbin 15 shown in FIG. It is more suitable for automation because it can be constructed by repeating the simple operation of clipping the coil 11 with divided bobbins.

[Effects of the Invention] According to the present invention, the outer peripheral flange portion 15a of the bobbin 15 is interposed between the outer peripheral surface of the excitation coil 11 and the inner peripheral surface of the outer flange portion 13a of the main yoke member 13.

As a result, the inner circumferential surface of the outer flange portion 13a and the excitation coil 11 are reliably separated from each other, and winding distortion of the excitation coil 11 can be suppressed, so that it is possible to prevent the two from coming into contact and causing poor insulation. . Furthermore, by fitting the protrusions 15j provided on the inner and outer peripheries of the bobbin 15 into the annular grooves 13d provided at opposing positions on the main yoke member 13,
There is an effect that the excitation coil 11 can be positioned within the yoke main member 13 and the excitation coil 11 can be stably arranged at an optimum position within the yoke main member 13. At the same time, it also serves to prevent the bobbin 15 holding the excitation coil 11 from being pulled out in the axial direction.

In addition, the present invention can cope with the conventional technology by changing the bobbin shape, and the above effects can be obtained with less cost increase.
Furthermore, since the excitation coil can be manually wound and the bobbin can be assembled later, it is ideal for automatic assembly of an excitation device.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of an excitation device for an electromagnetic clutch according to an embodiment of the present invention, Fig. 2 is an external perspective view of the bobbin used in Fig. 1, and Fig. 3 shows the usage state of Fig. 2. A plan view, FIGS. 4 and 5 are main part sectional views showing the state in which the excitation coil assembly is housed in the main yoke member, and FIG. 6 is an external perspective view showing the excitation coil assembly used in FIG. 1. 7 are external perspective views showing other embodiments. DESCRIPTION OF SYMBOLS 1... Rotating machine, 6... Output rotating body, 8... Input rotating body, 10... Excitation device, 11... Excitation coil, 1
2... Excitation coil assembly, 13... Yoke main member, 1
3a...Outer flange part, 13b...Inner flange part, 15...Bobbin, 15a...Outer flange part,
15c...Inner house 2 drawings ¥ 3 drawings Tail 4 drawings Height 6 drawings Height S drawing

Claims (3)

[Claims] 1. An excitation device for an electromagnetic clutch comprising a yoke main member constituting a part of a main magnetic circuit, an excitation coil serving as a source of magnetic flux, and an annular bobbin with a substantially U-shaped cross section for holding the excitation coil. an opening is opened in the axial direction, and protrusions are integrally provided on the inner and outer peripheries of the bobbin, while an annular groove is provided in the yoke main member at a position facing the protrusion of the bobbin. An exciting device for an electromagnetic clutch, characterized in that the bobbin protrusion is fitted into the annular groove. 2. 2. The exciting device for an electromagnetic clutch according to claim 1, wherein the bobbin is formed by forming a plurality of bobbins continuously into a ring shape. 3. An exciting device for an electromagnetic clutch according to claim 1, wherein the bobbin is divided into a plurality of parts.