JPH0756300B2 - Electromagnetic coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has an electromagnetic coupling device for connecting and disconnecting the transmission of rotational torque and braking of a rotating body by excitation and non-excitation of an exciting coil, and in particular, an exciting coil is provided therein. The present invention relates to an electromagnetic coupling device including an electromagnet including a yoke and a resin-made terminal block fixed to the back surface of the yoke.

[Conventional technology]

For example, in an electromagnetic clutch as an electromagnetic coupling device mounted on a refrigerant compressor as a vehicle air conditioner, a pair of terminals are insert-molded in a resin-made terminal block fixed to the rear surface of the yoke. Through the terminal of
The exciting coil is connected to an external electric circuit.

An example of this type of electromagnetic coupling device is, for example, Jitsuko Sho 57-26980.
What is disclosed in the publication is known, and FIG. 7 is a longitudinal sectional view of an electromagnet provided in this electromagnetic coupling device. In the figure, an electromagnet 1 is a yoke 2 having an annular groove 2a.
An exciting coil 4 wound around a coil bobbin 3 having a U-shaped cross section is provided inside the annular groove 2a, and a through hole 2b formed at the bottom of the annular groove 2a. From the hole 3a of the coil bobbin 3 facing the coil bobbin 3, both ends 5 of the winding start and the winding end of the exciting coil 4 are drawn out. Reference numeral 6 denotes a terminal block formed of a resin material in a box shape and having a projecting opening 6a fitted in the through hole 2b. The terminal block 6 is fitted in the concave groove 7a of the mounting plate 7, and the concave groove 7a is formed. It is fixed to the back surface of the yoke 2 by a cut-and-raised piece (not shown) formed in the portion. The exciting coil 4 drawn out from the through hole 2b
The both ends 5 of the winding start and the winding end are drawn into the terminal block 6. Further, a pair of terminals 8 are integrally formed in the terminal block 6 by insert molding, and the winding start and winding end ends 5 of the exciting coil 4 drawn into the terminal block 6 are
The lead wires 9 are caulked and fixed to the pair of terminals 8, respectively, and are electrically connected to the lead wires 9 which are also caulked and fixed to the pair of terminals. The coil bobbin 3 and the terminal block 6 configured as described above include a caulking piece 10 formed in the opening of the annular groove 2a,
It is fixed by a caulking piece (not shown) formed in the concave groove 7a portion, and is exposed to the outside of the exciting coil 4 shown by the symbol A in the figure, and the terminal block 6 shown by the symbol B in the figure.
Resin 11 is filled in the winding start and winding end portions 5 of the exciting coil 4 drawn into the inside and the connecting portion between the terminal 8 and the through hole 2b of the yoke 2 shown by the symbol C in the drawing. The excitation coil 4 and the connected portion are configured to prevent insulation failure and disconnection.

With this configuration, the coil bobbin 3 around which the exciting coil 4 is wound is loosely fitted in the annular groove 2a of the yoke 2, and both ends 5 of the exciting coil 4 at the start and end of the winding are placed in the terminal block 6. After being taken out to and connected to the terminal 8, the exposed portion A of the exciting coil 4 to the outside and the winding portion B between the winding start and end portions 5 of the exciting coil 4 drawn into the terminal block 6 and the terminal 8 are connected. , And in the through hole 2b C of the yoke 2, the resin 11
The magnetizing coil 4 is insulated and fixed in the annular groove 2a of the yoke 2 by pouring.

[Problems to be Solved by the Invention]

However, in such a conventional electromagnetic coupling device, as described above, the exposed portion A of the exciting coil 4, the winding start and end portions 5 of the exciting coil 4 and the connection portion B between the terminal 8 and The resin 11 for preventing disconnection due to insulation failure or vibration is poured into the through hole 2b C of the yoke 2, and since such casting work is performed during the production process, the work takes a long time. In short, there was a problem that productivity was reduced and labor was heavy.

The present invention has been made in view of the above points, and provides an electromagnetic coupling device capable of preventing disconnection due to insulation failure, vibration, etc. without performing resin injection work and improving productivity. The purpose is to do.

[Means for Solving the Problems]

In order to achieve such an object, in the present invention, the coil bobbin is divided into two members that can be joined to each other to be formed into a hollow ring as a whole, and the exciting coil is wound and disposed in an intermediate portion thereof. The cylindrical opening formed on the yoke was inserted into the through hole formed in the bottom of the annular groove of the yoke, and both ends of the exciting coil at the winding start and the winding end were drawn into the terminal block from the cylindrical opening. .

In addition, a protruding opening formed on the bottom of the housing of the terminal block is fitted into a through hole formed in the yoke to align the housing, and the housing is attached to the rear surface of the yoke. It is fixed to the rear surface of the yoke by a cut-and-raised piece of a welded mounting plate, the lid body is press-fitted into the opening in the upper part of the housing through the packing made of an elastic material, and the winding drawn from the projecting opening portion. The connection between the beginning and the end of the winding and the pair of terminals in the terminal block was cut off from the outside.

Further, a cylindrical opening is formed in the coil bobbin from which both ends of the winding start and end of the exciting coil are formed, and fitted into a through hole formed in the yoke, and both ends of the winding start and end are drawn in. A protruding opening was formed in the bottom of the terminal block, and the cylindrical opening was press-fitted and fixed in the protruding opening via a rubber bush.

[Work]

Since the coil bobbin is divided into two members and the whole is formed in a hollow ring shape, and the exciting coil is arranged in this hollow portion, a waterproof measure is provided, so that moisture enters from the outside of the wound exciting coil. And no insulation failure occurs.

In addition, since a waterproof measure is constructed by inserting the elastic packing into the housing of the terminal block and press-fitting the lid, both ends of the exciting coil and the end of the winding and the inside of the terminal block Insulation failure does not occur at the connection part with the pair of terminals.

Furthermore, in the penetration yard drilled in the bottom of the yoke,
By fitting the cylindrical opening of the coil bobbin and the projecting opening of the terminal block via the rubber bush, moisture does not enter through the through hole and insulation failure is prevented.

Then, in constructing such a waterproof measure, the cylindrical opening of the coil bobbin and the protrusion formed on the housing of the terminal block are fitted into the through hole formed in the bottom of the yoke. As a result, the coil bobbin and the casing are prevented from rotating, and the caulking piece of the yoke and the cut-and-raised piece of the mounting plate welded to the yoke prevent it from coming off. The disconnection of the connection between the terminals at the beginning and end of the winding and the terminal is prevented.

〔Example〕

1 to 5 show an example in which the electromagnetic coupling device according to the present invention is applied to an electromagnetic clutch of a compressor. FIG. 1 is a longitudinal sectional view of the electromagnetic clutch, FIG. 2 is a side view of the same, and FIG. Is a vertical sectional view of the electromagnet, FIGS. 4 (a) and 4 (b) are vertical sectional views of the coil bobbin, FIG. 5 (a) is a plan view of the terminal block shown without the lid, and FIG. 5 (b) is Similarly, the front view and FIG. 5 (c) are the bottom views.

In the figure, the electromagnetic clutch 12 includes a yoke 14 fixed to a housing of a compressor (not shown) through a mounting plate 13, and the yoke 14 is formed in an annular shape having a U-shaped cross section. In the annular groove 14d, the exciting coil 1
5 is wound around a coil bobbin, which will be described later, and is internally provided. In addition, the cylindrical portion 16 of the housing has a rotor 1 that has an annular groove 17a that is crowned in the yoke 14 in an idle state from the opening side.
A bearing 7 is supported by a bearing 18 so as to be freely rotatable and restricted from moving in the axial direction. On the other hand, at the tip of the drive shaft 19 penetrating the cylindrical portion 16 provided in the compressor, a hub 20 formed in a cylindrical shape with a flange is attached by shafts and fixed to the drive shaft 19 with a bolt 21. On the leaf spring 22 tacked to the hub 20, an armature 23 formed in the shape of a ring is used as a friction surface.
23a is tacked with the friction surface 17b of the rotor 17 facing it.

The armature 23 is formed of an outer ring member 23b and an inner ring member 23c that are concentrically arranged with an annular gap 24 therebetween, and between the inner ring member 23c and the flange 20a of the hub 20, A stopper rubber 25 is inserted and sandwiched.
That is, the armature 23 is elastically held by the hub 20 by the leaf spring 22, and between the rotor 17 and the armature 23,
A gap indicated by a symbol G in the drawing is formed. 26 is the rotor
A pulley that is fitted and welded to the outer periphery of 17 and is drivingly connected to a pulley provided on the crankshaft of an automobile engine by a belt, and is configured to rotate by being driven from the engine side. . Reference numeral 27 denotes a terminal block (described later) that constitutes an electromagnet 28 together with the yoke 14 and includes an exciting coil 15
Is energized by ON-OFF control of an external electric circuit via this terminal block 27, the generated magnetic flux causes the armature 23 to be attracted to the rotor 17, and the rotation of the rotor 17 is rotated by the armature 23, the leaf spring 22 and the hub. It is configured to be transmitted to the drive shaft 19 via 20.

Next, the electromagnet 28, which is a main part of the present invention, will be described. The yoke 14 of the electromagnet 28 is formed in an annular shape having a U-shaped cross section as a whole by the inner and outer peripheral wall portions 14a and 14b and the bottom portion 14c.
The tapers 14a and 14b are provided with tapers that become narrower toward the bottom 14c. These inner and outer peripheral walls 14a, 14b and the bottom
An exciting coil 15 wound around a coil bobbin 29 and shielded from the outside is internally provided in an annular groove 14d formed by 14c, and a through hole 14e is provided in the bottom portion 14c.

The coil bobbin 29 is made of a resin material and is divided into an inner coil bobbin 30 shown in FIG. 4 (a) and an outer coil bobbin 31 shown in FIG. 4 (b). Of these, the inner coil bobbin 30 includes a cylindrical portion 30b in which an inner peripheral wall portion 14b of the tapered yoke 14 is in contact with an inner peripheral surface 30a having a taper, and a locking groove 30c is formed on the outer side of the annular groove.
An annular flange portion 30d positioned so as to close the open end of 14d and a bent portion 30e are formed in an annular shape having an L-shaped cross section. Further, the outer coil bobbin 31 has a cylindrical portion 31b in which the outer peripheral wall portion 14a of the tapered yoke 14 is in contact with the tapered outer peripheral surface 31a and a pair of cylindrical opening portions 31c having through holes. And an annular flange portion 31d formed to be in contact with the bottom plate 14c of the annular groove 14d and a plurality of engaging portions 31e formed in the circumferential direction are formed in an annular shape having an inverted L-shaped cross section. Then, the inner coil bobbin 30 is wound with an exciting coil 15 having a self-bonding property which is a double-structured enameled wire in which a self-bonding layer is applied onto an insulating layer, for example, and the winding start of this exciting coil 15 is started. The inner coil bobbin 30 and the outer coil bobbin 31 around which the exciting coil 15 is wound are joined while the end portion 15a and the winding end portion 15b are inserted into the cylindrical opening 31c. When joining the coil bobbins 30 and 31, the engaging groove 30c provided on the inner coil bobbin 30 and the engaging portion 31e provided on the outer coil bobbin 31 are engaged to temporarily fix the coil bobbin 29.
The entire circumferences of the mating surfaces 32, 33 of 30, 31 are welded by, for example, ultrasonic welding, and the coil bobbin 29 is finally fixed and completely integrated. Note that 30f and 31f are concave grooves for guiding the winding start end 15a and the winding end end 15b of the exciting coil 15 to the through holes of the cylindrical opening 31c.

The coil bobbin 29 assembled externally in this way is
The tapered inner peripheral portion 30a and the outer peripheral portion 31a of both coil bobbins 30 and 31 are press-fitted into the annular groove 14d while being fitted with the tapered inner and outer peripheral wall portions 14a and 14b formed in the annular groove 14d of the yoke 14. By crimping a plurality of caulking pieces 14f formed by pressing at the open end of the annular groove 14d, the removal from the annular groove 14d is restricted and fixed. Further, the cylindrical opening 31c of the outer coil bobbin 31 is connected to the yoke 1
4 is inserted into the through hole 14e.

The yoke 1 into which the cylindrical opening 31c of the coil bobbin 29 is inserted
The housing 34 of the terminal block 27, which is inserted from the through hole 13a of the mounting plate 13 welded to the back surface of the yoke 14, is inserted into the through hole 14e of FIG.
The side projecting opening 34a is fitted to the coil bobbin 2
The cylindrical opening 31c of 9 is press-fitted into the center hole of the waterproof rubber bush 35 fitted in the protruding opening 34a.

The housing 34 of the terminal block 27 is made of a resin material and integrally formed with a protruding opening 34a having a pair of through holes formed in the bottom, a housing 34b opening upward, and a pair of mounting flanges 34c. Formed and front-facing housing
Equipped with 34d. Further, the terminal block 27 is provided with a lid body 37 which is press-fitted into the housing 34 via a backing 36 made of an elastic material, and a pair of terminals 38a, 38 insert-molded in the housing 34.
In b, a winding start end 15a and a winding end end 15b of the exciting coil 15 drawn from the cylindrical opening 31c of the coil bobbin 29 are shown.
And are connected. The terminals 38a and 38b are extended in the housing 34d and are connected to an external electric circuit in the housing 34d. Further, between the pair of terminals 38a, 38b, a surge absorbing diode 39 connected to them is arranged, and the terminal block 27 is a cut-and-raised piece formed on the mounting plate 13 by press working.
Yoke by bending 13b and 13c into the groove of flange 34c.
It is fixed on the back of 14. Reference numeral 34e is a protrusion provided on the outer periphery of the housing 34b, and is engaged with the lid body 37.

The operation of the electromagnetic clutch configured as above will be described. Since the exciting coil 15 is connected to the external electric circuit via the terminals 38a and 38b in the terminal block 27, when the exciting coil 15 is energized by ON-OFF control of this electric circuit, the magnetic flux generated causes the armature 23 to move. Is magnetically attracted to the rotor 17 against the spring force of the leaf spring 22, the rotation of the rotor 17 rotating together with the pulley 26 driven from the engine side of the automobile is transmitted to the drive shaft 19, and the compressor is driven. It

When the excitation of the exciting coil 15 is released from this state, the magnetic attraction of the armature 23 is released, so the armature 23 is separated from the rotor 17 by the spring force of the leaf spring 22 and the friction surface 23
A gap G is formed between a and 17b, and the pulley 26 drives the drive shaft 1
The transmission of rotation to 9 is cut off and the compressor stops.

Next, the assembling operation of the electromagnet 28 will be described. Outside the yoke 14, the coil bobbin 29 is divided into an inner coil bobbin 30 and an outer coil bobbin 31, so that the inner coil bobbin 30 is first wound around the inner coil bobbin 30 with multiple exciting coils 15 having a self-bonding property. Next, the inner coil bobbin 30 and the outer coil bobbin 31
When joining both coil bobbins 30, 31, the engaging groove 30c of the inner coil bobbin 30 and the engaging portion 31e of the outer coil bobbin 31 are engaged and the coil bobbin 29 is temporarily fixed. 15 is the inner coil bobbin 30
It is surrounded by a coil bobbin 29 composed of an outer coil bobbin 31 and an outer coil bobbin 31. At this time, the exciting coil 15 is drawn out from the cylindrical opening 31c at the winding start end 15a and the winding end end 15b. Next, the entire circumferences of the mating surfaces 32, 33 of the coil bobbins 30, 31 are welded by ultrasonic welding to permanently fix the coil bobbin 29. The coil bobbin 29 assembled outside in this manner is press-fitted into the annular groove 14d of the yoke 14, but since the inner peripheral surface of the annular groove 14d and the outer peripheral surface of the coil bobbin 29 are tapered, the coil bobbin 29 is firmly fixed. After the press-fitting and fixing, the crimping piece 14f provided at the opening end of the annular groove 14d is caulked, whereby the coil bobbin 29 is fixed while being prevented from coming off from the annular groove 14d. At this time, the through hole 14 of the yoke 14
Since the protruding opening 34a of the terminal block 27 is inserted in e,
The cylindrical opening 31c of the coil bobbin 29 is press-fitted into the rubber bush 35 fitted in the projecting opening 34a, and both ends 15a and 15b of the exciting coil 15 are drawn into the terminal block 27, and the terminal 38a,
38b is connected respectively. After connection, the inside of the housing 34 is insulated from the outside by pressing the lid 37 into the opening of the housing 34c via the packing 36.

As a result of the assembly in this way, the exciting coil 15 is surrounded by the coil bobbin 29 made of resin material, so that the yoke 14
It is completely insulated against, and moisture does not enter from the outside.

In addition, the inside of the housing 34 in which both ends 15a and 15b of the exciting coil 15 and the terminals 38a and 38b are connected to each other is provided with a packing 36 made of an elastic material.
Since it is blocked by the lid via the and is shielded from the outside, water does not enter the connection part.

Further, in the through hole 14e of the yoke, the coil bobbin 29
The cylindrical opening 31c and the projecting opening 34a of the terminal block 27 are
Since it is fitted through the rubber bush 35, the through hole 14
Water does not enter the terminal block 27 or the coil bobbin 29 from e.

6 (a) and 6 (b) are longitudinal sectional views of the coil bobbin main part showing another embodiment of the present invention, and FIG. 6 (a) is a longitudinal sectional view of the outer coil bobbin main part. (B) is a longitudinal sectional view of an inner coil bobbin main part. That is, in this embodiment, the coil bobbin is divided into the inner coil bobbin 40 and the outer coil bobbin 41, and the inner coil bobbin 40 is integrally formed in a ring shape having a U-shaped cross section with the bottom plate 40a, the outer flange 40b, and the inner flange 40c. At one position of the annular bottom plate 40a, the winding start end 15a of the exciting coil 15 is provided.
And a pair of cylindrical openings 40d into which the winding end portions 15b are inserted.
Are integrally formed. Further, the outer coil bobbin 41 is formed in a wheel plate shape, and is configured to close the open end of the inner coil bobbin 40. The volumes of the welded portions 41b and 41c formed on the inner and outer circumferences of the outer coil bobbin 41 are smaller than the volumes of the annular grooves 40f and 40e formed on the inner and outer peripheral edges of the opening of the inner coil bobbin 40. 40g is a groove for guiding the winding start end 15a and the winding end 15b of the exciting coil 15 to the through hole of the cylindrical opening 40d.

With this configuration, the winding coil 15 is housed in the inner coil bobbin 40, and the winding start end portion 15a and the winding end end portion 15b thereof have a cylindrical opening 40.
After being inserted into d and pulled out to the outside, the fitting portion 41a of the outer coil bobbin 41 is press-fitted and closed at the opening end of the inner coil bobbin 40, and the welding portions 41b and 41c of the outer coil bobbin 41 are ultrasonically welded. Weld the mating surfaces. In this case, the volume of the welded portions 41b, 41c of the outer coil bobbin 41 is formed to be smaller than the volume of the annular grooves 40e, 40f of the inner coil bobbin 40, so that at the time of welding after fitting these, from the end surface of the coil bobbin. , The flash does not protrude.

After being assembled in this manner, it is housed in the annular groove 14d of the yoke 14 and caulked by the caulking piece 14f, which is the same as the above-mentioned embodiment.

Although the cylindrical openings, 31c, 40d are integrally formed with the coil bobbin in each of the above-described embodiments, the rubber bush may be formed separately from the coil bobbin.

Further, in each of the above-mentioned embodiments, the exciting coil is the magnet wire having self-bonding property.
An exciting coil made of a general magnet wire wound around 30 and 40 may be fixed by winding a tape.

Furthermore, in each of the above-described embodiments, the example in which the present invention is applied to the electromagnetic clutch has been shown, but the present invention can be applied to the electromagnetic brake in the same manner, and the same effect can be obtained. Furthermore, although the divided coil bobbins are fixed by ultrasonic welding in the above embodiments, they may be fixed by other fixing means such as an adhesive.

〔The invention's effect〕

As is clear from the above description, according to the present description, in the electromagnetic coupling device, the coil bobbin is divided into two members that can be joined to each other to form a hollow ring shape, and the electromagnetic exciting coil is wound and disposed in the hollow portion. At the same time, the cylindrical opening formed in the coil bobbin is inserted into the through hole formed in the bottom of the annular groove of the yoke, and the winding start and end ends of the exciting coil are connected to the terminal through the cylindrical opening. Since the water is prevented from entering from the outside to the place where the exciting coil is attached by pulling it into the table, the exciting coil is electrically completely insulated and an accident such as insulation failure can be prevented.

In addition, a protruding opening formed on the bottom of the housing of the terminal block is fitted into a through hole formed in the yoke to align the housing, and the housing is attached to the rear surface of the yoke. It is fixed to the rear surface of the yoke by a cut-and-raised piece of a welded mounting plate, the lid body is press-fitted into the opening in the upper part of the housing through the packing made of an elastic material, and the winding drawn from the projecting opening portion. By cutting off the connection between the start and end ends of the winding and the pair of terminals in the terminal block to the outside, water enters the connection between the winding start and end of the exciting coil and the pair of terminals. It is possible to prevent accidents such as poor insulation because it is electrically insulated completely.

Further, a cylindrical opening is formed in the coil bobbin from which both ends of the winding start and end of the exciting coil are formed, and fitted into a through hole formed in the yoke, and both ends of the winding start and end are drawn in. By forming a projecting opening at the bottom of the terminal block and press-fitting and fixing the cylindrical opening into the projecting opening via a rubber bush, the mounting position of the coil bobbin and the terminal block are inserted from the through holes. Water will not penetrate into the space and will be completely electrically insulated, preventing accidents such as poor insulation.

The cylindrical opening of the coil bobbin and the projecting opening formed in the housing of the terminal block are fitted into the through holes formed in the bottom surface of the yoke, so that the coil bobbin and the terminal block are separated by the yoke. Prevents disconnection of the exciting coil and its winding start and end parts and the connection part with the terminal because it is locked and fixed by the caulking piece of the yoke and the cut and raised piece of the mounting plate welded to this yoke. be able to.

Moreover, since such insulation failure and disconnection can be prevented without molding the resin, the preparation time is shortened, the productivity is improved, and the labor is reduced.

[Brief description of drawings]

1 to 5 show an example in which the electromagnetic coupling device according to the present invention is applied to an electromagnetic clutch of a compressor. FIG. 1 is a longitudinal sectional view of the electromagnetic clutch, FIG. 2 is a side view of the same, and FIG. Is a vertical sectional view of the electromagnet, FIGS. 4 (a) and 4 (b) are vertical sectional views of the coil bobbin, FIG. 5 (a) is a plan view of the terminal block shown without the lid, and FIG. 5 (b) is Similarly, FIG. 6 (a) is a bottom view, FIG. 5 (c) is a bottom view, and FIGS. 6 (a) and 6 (b) are longitudinal cross-sectional views of a coil bobbin main part showing another embodiment of the present description. ) Is a vertical sectional view of an outer coil bobbin main part, FIG. 6B is a vertical sectional view of an inner coil bobbin main part, and FIG. 7 is a vertical sectional view of an electromagnet provided in a conventional electromagnetic coupling device. 14 …… Yoke, 15 …… Excitation coil, 27 …… Terminal block, 28…
… Electromagnet, 29 …… Coil bobbin, 30,40 …… Inner coil bobbin, 31,41 …… Outer coil bobbin, 31c …… Cylindric opening, 34 …… Case, 34a …… Projecting opening, 35 …… Rubber bush , 36 …… packing, 37 …… lid, 38a, 38b …… terminals.

Claims (3)

[Claims] 1. An exciting coil wound around a coil bobbin,
A yoke in which the exciting coil is installed, a terminal block made of resin material fixed to the back surface of the yoke, and insert-molded in the terminal block are connected to the winding start end and the winding end end, respectively. In an electromagnetic coupling device including an electromagnet including a pair of terminals, the coil bobbin is divided into two members that can be joined to each other to form a hollow ring, and the exciting coil is wound in the hollow portion. At the same time, the cylindrical opening formed in the coil bobbin is inserted into the through hole formed in the bottom of the annular groove of the yoke, and the winding start and end ends of the exciting coil are connected to the terminal through the cylindrical opening. An electromagnetic coupling device characterized by being pulled into the table. 2. An exciting coil wound around a coil bobbin,
A yoke in which the exciting coil is installed, a terminal block made of resin material fixed to the back surface of the yoke, and insert-molded in the terminal block are connected to the winding start end and the winding end end, respectively. In an electromagnetic coupling device including an electromagnet composed of a pair of terminals formed in the housing, the through hole formed in the yoke is fitted with a projecting opening formed in the bottom of the housing of the terminal block. The housing is fixed to the rear surface of the yoke with a cut-and-raised piece of a mounting plate welded to the rear surface of the yoke, and a lid is inserted into an opening in the upper portion of the housing through an elastic packing. An electromagnetic coupling device, characterized in that a connection portion between the winding start and winding end portions and a pair of terminals in the terminal block, which are press-fitted and pulled in from the projecting opening, is cut off from the outside. 3. An exciting coil wound around a coil bobbin,
A yoke in which the exciting coil is provided, a terminal block made of a resin material fixed to the back surface of the yoke, a winding start end and a winding end end of the exciting coil insert-molded in the terminal block, respectively. In an electromagnetic coupling device provided with an electromagnet consisting of a pair of terminals connected to each other, a cylindrical opening from which both ends of the exciting coil are started and formed is formed in the coil bobbin, and a through hole is formed in the yoke. A protruding opening is formed at the bottom of the terminal block that fits into the hole and that both ends of the winding start and the end of winding are drawn, and the cylindrical opening is inserted into the protruding opening via a rubber bush. An electromagnetic coupling device characterized by being press-fitted and fixed.