Electromagnetic coil, electromagnetic clutch provided with same, and method for manufacturing same

Abstract

The invention provides a technology capable of realizing miniaturization and light weight of an electromagnetic coil. The electromagnetic coil (10) includes: a magnetic coil housing (20) having an annular housing groove (24); a frameless coil (30) directly housed in the housing groove (24); a covering body (40) which has elasticity and resin impregnation properties and covers the whole of the frameless coil (30); and an electrically insulating layer (50) which is formed from an electrically insulating thermosetting resin impregnated in the covering body (40) and which covers the surface of the frameless coil (30).

Description

Technical Field

[0001] The present invention relates to an electromagnetic coil, an electromagnetic clutch including the electromagnetic coil, and an improved technology for a method of manufacturing the electromagnetic coil. Background Art

[0002] The electromagnetic coil is provided in various electromagnetic devices such as electromagnetic clutches, and is also called an excitation coil. As such an electromagnetic coil, for example, Patent Document 1 (refer to Figure 1 , paragraph 0023) technology.

[0003] According to the electromagnetic coil disclosed in Patent Document 1, a coil bobbin on which a coil is wound is stored in a storage groove of a coil case (equivalent to an annular groove of a coil storage frame), and the coil bobbin and the coil are covered and fixed in the storage groove with a mold resin.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: JP 2020-085173 A Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] In recent years, from the perspective of miniaturization and lightness of electromagnetic equipment, it is required to realize miniaturization and lightness of electromagnetic coils of electromagnetic equipment. However, the electromagnetic coil known in Patent Document 1 is a structure in which a coil frame and a coil are molded in a storage groove using a layer of molding resin, so there are limitations on miniaturization and lightness.

[0009] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a technology capable of realizing miniaturization and weight reduction of an electromagnetic coil.

[0010] Technical solutions for solving technical problems

[0011] In the following description, in order to facilitate understanding of the present invention, reference numerals in the drawings are given in parentheses, but the present invention is not limited to the embodiments shown in the drawings.

[0012] According to the present invention, first, an electromagnetic coil (10) is provided, characterized in that it comprises:

[0013] A magnetic coil housing (20) having an annular receiving groove (24);

[0014] A frameless coil (30) is directly received in the receiving slot (24);

[0015] A covering body (40) having elasticity and resin impregnation properties, covering the entire frameless coil (30);

[0016] The electrical insulating layer (50) is composed of an electrically insulating thermosetting resin impregnated in the covering body (40) and covers the surface of the frameless coil (30).

[0017] Second, preferably, based on the electromagnetic coil described in the first aspect, the covering body (40) is made of knitted fabric.

[0018] Thirdly, preferably, based on the electromagnetic coil described in the first aspect, the covering body (40) is made of stretchable nonwoven fabric.

[0019] Fourthly, preferably, based on the electromagnetic coil described in any one of the first to third aspects, the covering body (40) is composed of a tape (41) that can be wound around the frameless coil (30).

[0020] Fifth, preferably, based on the electromagnetic coil described fourthly, the tape (41) is wound into at least two layers relative to the frameless coil (30).

[0021] Sixth, preferably, based on the electromagnetic coil described in any one of the first to fifth aspects, the frameless coil (30) is fixed to the storage groove (24) by the thermosetting resin.

[0022] Seventh, preferably, based on the electromagnetic coil described in the sixth aspect, the coil housing (20) has a recess (27) recessed from the side wall (26) that divides the storage groove (24),

[0023] At least a portion of the thermosetting resin is buried in the recess (27).

[0024] Eighth, preferably, an electromagnetic clutch (100) is provided, characterized in that it comprises:

[0025] The electromagnetic coil (10) described in any one of the first to seventh;

[0026] A first rotating body (101) on the driving side, which is made of magnetic material;

[0027] A second rotating body (102) on the passive side, which is capable of relatively rotating relative to the first rotating body (101);

[0028] an armature plate (103) made of a magnetic material, connected to the second rotating body (102), and arranged opposite to the side end surface (101a) of the first rotating body (101) with a gap (104);

[0029] The electromagnetic coil (10) is housed inside the first rotating body (101) in such a manner that, by energizing the frameless coil (30), a magnetic circuit is formed through the first rotating body (101) and the armature plate (103) and an attraction force is generated that causes the armature plate (103) to be electromagnetically attracted to the first rotating body (101).

[0030] In addition, according to the present invention, ninthly, a method for manufacturing an electromagnetic coil (10) is provided, wherein the electromagnetic coil (10) comprises:

[0031] A magnetic coil housing (20) having an annular receiving groove (24);

[0032] A frameless coil (30) is directly received in the receiving slot (24);

[0033] A covering body (40) having elasticity and resin impregnation properties, covering the entire frameless coil (30);

[0034] An electrical insulating layer (50), which is composed of an electrically insulating thermosetting resin impregnated in the coating (40) and covers the surface of the frameless coil (30);

[0035] The manufacturing method of the electromagnetic coil (10) is characterized by comprising:

[0036] A step of preparing the frameless coil (30);

[0037] Thereafter, a step of using the covering body (40) to cover the entire frameless coil (30);

[0038] Thereafter, a step of storing the frameless coil (30) covered by the covering body (40) in the storage groove (24);

[0039] Thereafter, a step of injecting a liquid thermosetting resin (70) having electrical insulation properties into the storage groove (24) to impregnate the coating (40) with the liquid thermosetting resin (70);

[0040] Thereafter, the step of forming the electrical insulating layer (50) is performed by heating the liquid thermosetting resin (70) impregnated in the coating (40) to cure the resin.

[0041] Effects of the Invention

[0042] According to the present invention, it is possible to provide a technology capable of achieving miniaturization and weight reduction of an electromagnetic coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a cross-sectional view of the electromagnetic coil of the embodiment.

[0044] Figure 2 yes Figure 1 The illustrated perspective view is of a structure in which a frameless coil is covered by a covering body.

[0045] Figure 3 Yes Figure 2 The illustrated structure is an enlarged cross-sectional view of a portion of a structure in which a frameless coil is covered with a covering body.

[0046] Figure 4 It is along Figure 3 Cross-sectional view of line 4-4.

[0047] Figure 5 middle, Figure 5 A is an explanatory diagram for explaining the winding process of the electromagnetic coil of the embodiment. Figure 5 B is an explanatory diagram for explaining the holding process of the electromagnetic coil of the embodiment. Figure 5 C is an explanatory diagram for explaining the component connection preparation process of the electromagnetic coil of the embodiment.

[0048] exist Figure 6 middle, Figure 6 A is an explanatory diagram for explaining the coating process of the electromagnetic coil of the embodiment. Figure 6 B is an explanatory diagram for explaining the connection process of the electromagnetic coil of the embodiment. Figure 6 C is an explanatory diagram for explaining the additional coating process of the electromagnetic coil of the embodiment.

[0049] Figure 7 This is an explanatory diagram for explaining the step of storing the electromagnetic coil according to the embodiment.

[0050] Figure 8 This is an explanatory diagram for explaining a preheating process of the electromagnetic coil in the embodiment.

[0051] Fig. 9 This is an explanatory diagram for explaining the impregnation treatment process of the electromagnetic coil of the example.

[0052] Fig.10 This is an explanatory diagram for explaining a curing process of the electromagnetic coil according to the embodiment.

[0053] Fig.11 Yes Figure 1 A cross-sectional view of an electromagnetic clutch with an electromagnetic coil is shown. DETAILED DESCRIPTION

[0054] Embodiments of the present invention will be described below based on the drawings. It should be noted that the embodiments shown in the drawings are examples of the present invention, and the present invention is not limited to these embodiments.

[0055] <Example>

[0056] Please refer to the attached Figure 1 The electromagnetic coil 10 of the embodiment, the electromagnetic clutch 100 including the electromagnetic coil 10 , and the method for manufacturing the electromagnetic coil 10 will be described.

[0057] Figure 1 The electromagnetic coil 10 shown is used in electromagnetic devices such as electromagnetic clutches and electromagnetic brakes. The electromagnetic coil 10 includes a magnetic annular coil housing 20 based on a center line CL, a coil 30 accommodated in the coil housing 20, a coating 40 that has elasticity and resin impregnation and covers the entire coil 30, and an electrical insulating layer 50 that is made of an electrically insulating thermosetting resin impregnated in the coating 40 and covers the surface of the coil 30.

[0058] The coil housing 20 has a U-shaped cross-section with one end open, and has an annular housing groove 24 defined by an inner side wall 21 , an outer side wall 22 , and a bottom wall 23 that blocks ends of the side walls 21 , 22 .

[0059] The surface 25 on the opposite side of the bottom wall 23 in the coil housing 20 is called the open end surface 25. The opening 24a of the storage groove 24 is located on the side of the open end surface 25 (the side opposite to the bottom wall 23). For the groove width Gw of the storage groove 24, it is preferred that the opening 24a is wide. If it is wide, it is easy to inject the liquid thermosetting resin described later into the storage groove 24.

[0060] The coil 30 is directly received in the receiving groove 24 of the coil housing 20 without passing through a coil frame. That is, the coil 30 is a frameless coil structure in which the coil frame is eliminated. Hereinafter, the coil 30 is sometimes referred to as a "frameless coil 30". The frameless coil 30 is composed of a coil winding wire 31 such as a copper wire. The cross-sectional shape of the frameless coil 30 is preferably configured as a quadrilateral cross-section (including a substantially quadrilateral cross-section) in which the coil winding wires 31 are tightly packed. The portion of the electrical insulating layer 50 on the side of the opening 24a of the receiving groove 24 is a structure having only the thickness amount (including the approximate thickness amount) of the coating 40, that is, it is composed only of an electrically insulating thermosetting resin impregnated in the coating 40.

[0061] The frameless coil 30 is fixed to the storage groove 24 by the thermosetting resin 50 (electrical insulating layer 50 ). Therefore, it is possible to prevent the frameless coil 30 from falling out of the storage groove 24 .

[0062] The coil case 20 has a recess 27 recessed from the inner surface 26 (surface 26 on the storage groove 24 side) on the inner surface 26 of at least one of the inner peripheral side wall 21 and the outer peripheral side wall 22. The recess 27 is formed on a part of the inner surface 26 or the entire circumference.

[0063] In this way, the coil housing 20 has a recessed portion 27 recessed from the side wall 21 of the storage groove 24. At least a portion of the thermosetting resin 50 (electrical insulating layer 50) is buried in the recessed portion 27. Therefore, at least a portion of the thermosetting resin 50 is hooked in the recessed portion 27, so that the frameless coil 30 can be prevented from falling off from the coil housing 20 more firmly.

[0064] As described above, the covering body 40 is formed of a member having elasticity and resin impregnation properties.

[0065] For example, the covering body 40 is preferably made of knitted fabric. The covering body 40 is made of knitted fabric that is more stretchable than woven fabric. Since the covering body 40 is stretchable, it is not easy to wrinkle when covering the skeletonless coil 30, and can be closely attached to the skeletonless coil 30. The covering body 40 made of knitted fabric can uniformly cover the skeletonless coil 30 and impregnate and maintain the liquid thermosetting resin. Therefore, a uniform electrical insulating layer 50 can be formed on the surface of the skeletonless coil 30.

[0066] As another example, the covering body 40 is preferably made of a stretchable nonwoven fabric. As the stretchable nonwoven fabric, a stretchable nonwoven fabric such as "FELIBENDY" (registered trademark) manufactured by KurarayKuraflex Co., Ltd. is preferably exemplified. In addition, as a technology of stretchable nonwoven fabric, JP 2012-012758A (invention title: High elongation stretchable nonwoven fabric, applicant: KurarayKuraflex Co., Ltd.) is known.

[0067] The covering body 40 is formed by a stretchable nonwoven fabric that is more stretchable than a woven fabric. Since the nonwoven fabric is stretchable, it is not easy to wrinkle when covering the frameless coil 30, and can be closely attached to the frameless coil 30. The covering body 40 composed of the nonwoven fabric can uniformly cover the frameless coil 30 and impregnate and maintain the thermosetting resin. Therefore, a uniform electrical insulation layer 50 can be formed on the surface of the frameless coil 30.

[0068] Further, if Figure 2 and Figure 3 As shown, the covering body 40 is composed of a belt 41 that can be wound around the frameless coil 30. The belt 41 is composed of a component that has elasticity and resin impregnation, such as a knitted fabric or a stretchable nonwoven fabric. In this way, by winding the belt 41 around the frameless coil 30, the entire frameless coil 30 can be covered. Therefore, it is easy to cover the frameless coil 30 as a whole.

[0069] By overlapping and winding the coating 40 (multiple winding) on ​​the frameless coil 30, the amount of the liquid thermosetting resin impregnated into the coating 40 can be easily and reliably controlled. As a result, the required thickness of the electrical insulating layer 50 can be easily and reliably controlled.

[0070] For example, Figure 3 and Figure 4 As shown, the tape 41 is wound into multiple layers (at least two layers) with respect to the frameless coil 30. For example, the tape 41 is preferably wound into multiple layers while overlapping half of the tape width Tw each time. In this way, since half of the tape width Tw is overlapped each time, no gap appears between adjacent tapes 41 and tapes 41, and the electrical insulation layer 50 can be reliably formed on the periphery of the frameless coil 30.

[0071] In this way, the covering body 40 is preferably a strip-shaped structure that can further easily cover the frameless coil 30 compared to a sheet-shaped structure. Since the strip-shaped covering body 40 that can easily cover the frameless coil 30 is overlapped and wound, the electrical insulating layer 50 can be formed without a gap, and the required thickness of the electrical insulating layer 50 can be managed by the number of overlapping covering bodies 40. That is, by managing the thickness of the covering body 40 covering the frameless coil 30, the amount of liquid thermosetting resin impregnated with the covering body 40 can be easily and reliably managed. As a result, the required thickness of the electrical insulating layer 50 can be easily and reliably managed.

[0072] like Figure 2 As shown, the frameless coil 30 is connected to an accessory component 63 such as a thermal fuse as needed, and the ends 31a, 31a (connection ends 31a, 31a) of the coil winding wire 31 are connected to an external wiring 64. The thermal fuse melts when the ambient temperature exceeds a specified value, thereby cutting off the power supply to the frameless coil 30.

[0073] The above description of the electromagnetic coil 10 is summarized as follows.

[0074] like Figure 1 As shown, the electromagnetic coil 10 includes a magnetic coil housing 20 having an annular receiving groove 24, a frameless coil 30 directly received in the receiving groove 24, a sheath 40 having elasticity and resin impregnation properties and covering the entire frameless coil 30, and an electrical insulating layer 50 formed of an electrically insulating thermosetting resin impregnated in the sheath 40 and covering the surface of the frameless coil 30.

[0075] Thus, the electromagnetic coil 10 of this embodiment has the greatest feature of forming the electrical insulation layer 50 on the surface of the frameless coil 30 by impregnating the coating 40 with an electrically insulating liquid thermosetting resin. In other words, the electromagnetic coil 10 does not simply form the electrical insulation layer 50 on the surface of the frameless coil 30 using the liquid thermosetting resin injected into the storage groove 24 of the coil housing 20.

[0076] In detail, the coil 30 is directly received in the storage groove 24 of the coil housing 20 without passing through the coil skeleton. That is, the coil 30 is a structure of a frameless coil 30 in which the coil skeleton is eliminated. The frameless coil 30 is entirely covered by a coating 40 having elasticity and resin impregnation properties. The coating 40 is impregnated with an electrically insulating liquid thermosetting resin. By means of the impregnated thermosetting resin, an electrical insulating layer 50 can be formed on the surface of the frameless coil 30. The coating 40 constitutes a substrate for forming and maintaining the electrical insulating layer 50. The electrical insulating layer 50 is formed only on the interior and surface of the coating 40 by impregnation, and electrically insulates the side walls 21, 22 (slot side walls 21, 22) of the coil housing 20 that divide the storage groove 24 from the surface of the frameless coil 30.

[0077] Therefore, the slot side walls 21 and 22 can be electrically insulated from the frameless coil 30 without the coil bobbin. Since the coil bobbin is eliminated, the electromagnetic coil 10 can be made smaller and lighter.

[0078] Moreover, the electrical insulating layer 50 is formed only inside and on the surface of the coating 40 serving as the base material by impregnation. Therefore, the thickness of the electrical insulating layer 50 can be relatively thin. For example, the portion of the electrical insulating layer 50 on the side of the opening 24a of the storage groove 24 is a structure having only the thickness of the coating 40 (including the approximate thickness), that is, it is formed only by the electrically insulating thermosetting resin impregnated in the coating 40. There is no need to fill the entire storage groove 24 with the electrically insulating liquid thermosetting resin. The groove width Gw and the groove depth Gd of the storage groove 24 can be set small. As a result, the electromagnetic coil 10 can be miniaturized and lightweight.

[0079] In addition, the covering body 40 has elasticity and is therefore less likely to wrinkle when covering the frameless coil 30. Therefore, the covering body 40 can be uniformly impregnated with the liquid thermosetting resin, and thus the electrical insulating layer 50 of uniform thickness can be obtained.

[0080] Next, a method for manufacturing the electromagnetic coil 10 having the above-described structure will be described.

[0081] The structure of the electromagnetic coil 10 according to the assembling method of the present embodiment is summarized as follows.

[0082] like Figure 1As shown, the electromagnetic coil 10 includes: a magnetic coil housing 20 having an annular receiving groove 24; a frameless coil 30 directly received in the receiving groove 24; a sheath 40 having elasticity and resin impregnation properties and covering the entire frameless coil 30; and an electrical insulating layer 50, which is composed of an electrically insulating thermosetting resin impregnated in the sheath 40 and covers the surface of the frameless coil 30.

[0083] The method for manufacturing the electromagnetic coil 10 includes the following steps.

[0084] First, if Figure 5 As shown in A, the coil winding wire 31 is wound around a winding tool 61 by a winding machine (shown) to manufacture the frameless coil 30 (winding step).

[0085] After the winding process, Figure 5 As shown in B, the frameless coil 30 is removed from the winding tool 61, and the coil state is held by the temporary fixing tape 62 (holding step).

[0086] After this holding process, Figure 5 As shown in FIG. 3C, the connection ends 31a, 31a of the coil winding wire 31 are led out from the frameless coil 30 (parts connection preparation step). The connection ends 31a, 31a are connected to the external wiring 64 (see FIG. 3C). Figure 2 ) part. In the component connection preparation process, when the accessory component 63 (refer to Figure 2 ), the midway portion of the coil winding wire 31 of the frameless coil 30 is cut, and the component connecting portions 31b, 31b are led out from the midway of the coil winding wire 31 (the end portions 31b, 31b are cut off).

[0087] By executing the holding step and the component connection preparation step, the frameless coil 30 is prepared. Hereinafter, completion of the holding step and the component connection preparation step is regarded as execution of the step (preparation step) of preparing the frameless coil 30.

[0088] After this preparation process, Figure 6 As shown in FIG. 1A, the entire frameless coil 30 is covered with a covering body 40 except for the connection end portions 31a, 31a and the component connection portions 31b, 31b (covering process). The covering process can be performed by winding the covering body 40, for example, composed of a tape 41, around the frameless coil 30. Through the covering process, the frameless coil 30 and the component connection portions 31b, 31b can be electrically insulated.

[0089] After the coating process, Figure 6As shown in B, the external wiring 64 is connected to the connection end portions 31a, 31a of the coil winding wire 31 (connection step). In this connection step, the accessory component 63 is connected to the component connection portions 31b, 31b as needed.

[0090] After this connection process, Figure 6 As shown in C, the connection ends 31a, 31a and the component connection parts 31b, 31b are covered with a covering body 40 (additional covering step). This additional covering step can be performed by wrapping the covering body 40, for example, composed of a belt 41, including the connection ends 31a, 31a, the component connection parts 31b, 31b and the accessory parts 63, around the frameless coil 30. This additional covering step can electrically insulate the connection ends 31a, 31a, the component connection parts 31b, 31b from the coil housing 20. It should be noted that since the accessory parts 63 and the external wiring 64 slightly protrude from the outer peripheral surface of the frameless coil 30, the covering body 40 also bulges accordingly (at Figure 6 In C, the bulged portion is shown larger for easier understanding).

[0091] After the additional coating process, Figure 7 As shown, the frameless coil 30 covered by the covering body 40 is stored, that is, installed in the storage groove 24 of the coil housing 20 (storage process). In this storage process, the coil housing 20 is pre-installed in the housing holding fixture 65 (carrying table 65). For example, a fixing plate 108 is pre-fixed to the bottom wall 23 of the coil housing 20. The coil housing 20 is installed in the housing holding fixture 65 with the fixing plate 108 facing downward. Therefore, the upper side of the storage groove 24 of the coil housing 20 is open. It should be noted that the shape and size of the housing holding fixture 65 are arbitrary. The result of this storage process, as shown in FIG. Figure 8 As shown, the frameless coil 30 is received in the receiving slot 24. Figure 6 As shown in C, the accessory parts 63 and the external wiring 64 slightly protrude from the outer peripheral surface of the frameless coil 30. Figure 8 As shown, even if the frameless coil 30 is pressed into the housing groove 24 , a gap 66 (space 66 ) is provided between the frameless coil 30 and the bottom wall 23 .

[0092] After this storage process, Figure 8 As shown, the thermosetting resin 70 and the coil housing 20 are preheated in a manner to maintain the fluidity of the liquid thermosetting resin 70 having electrical insulation properties (preheating process). For example, a container 81 containing the liquid thermosetting resin 70 is heated by a heater 82, and the liquid thermosetting resin 70 is maintained in a preheated state, thereby maintaining the fluidity of the thermosetting resin 70. In addition, the coil housing 20 after the storage process is placed in a preheating furnace 83 for preheating.

[0093] After the storage process and preheating process, Fig. 9 As shown, the liquid thermosetting resin 70 is injected into the storage groove 24 to impregnate the coating 40 with the liquid thermosetting resin 70 (impregnation process). For example, the thermosetting resin 70 can be injected into the storage groove 24 by flowing a predetermined amount of the liquid thermosetting resin 70 contained in the container 81 into the storage groove 24 (inflow method). After a certain period of time has passed since the injection, the coating 40 is impregnated with the liquid thermosetting resin 70 without omission.

[0094] More specifically, as described above, the upper side of the storage groove 24 of the coil housing 20 is open. If a certain amount of liquid thermosetting resin 70 is flowed into the storage groove 24, as shown in FIG. Fig.10 As shown, approximately the lower half of the frameless coil 30 covered by the covering body 40 is impregnated with the liquid thermosetting resin 70. The approximately upper half of the frameless coil 30 and the covering body 40 is impregnated with the liquid thermosetting resin 70 that flows into the storage groove 24. As a result, the liquid thermosetting resin 70 is impregnated into the covering body 40 without omission. Therefore, it is not necessary to fill the entire storage groove 24 with the liquid thermosetting resin 70.

[0095] After the impregnation process, Fig.10 As shown, the electric insulating layer 50 is formed by heating and curing the liquid thermosetting resin 70 impregnated in the covering body 40 (curing step). For example, the coil housing 20 after impregnation is placed in a curing heating furnace 84 for heating, thereby curing the liquid thermosetting resin 70 impregnated in the covering body 40.

[0096] After the curing step, the coil case 20 is cooled to room temperature, and a series of steps for manufacturing the electromagnetic coil 10 are completed.

[0097] The above description of the method for manufacturing the electromagnetic coil 10 is summarized as follows.

[0098] The method for manufacturing the electromagnetic coil 10 includes:

[0099] Step of preparing the frameless coil 30 ( Figure 5 A to Figure 5 C)

[0100] Then, a step of covering the entire frameless coil 30 with the covering body 40 is performed ( Figure 6 A shown in the coating process);

[0101] Thereafter, a step of housing the frameless coil 30 covered by the covering body 40 in the housing groove 24 is performed ( Figure 7 The storage process shown);

[0102] Thereafter, a step of impregnating the package 40 with the liquid thermosetting resin by injecting the liquid thermosetting resin 70 having electrical insulation properties into the storage groove 24 ( Fig. 9 The impregnation process shown in FIG.

[0103] Thereafter, a step of forming the electrical insulating layer 50 by heating and curing the liquid thermosetting resin impregnated in the coating 40 ( Fig.10 curing process shown).

[0104] Thus, the manufacturing method of the electromagnetic coil 10 of the present embodiment has the greatest feature of forming the electrical insulating layer 50 on the surface of the frameless coil 30 by impregnating the coating 40 with the electrically insulating liquid thermosetting resin 70. In other words, the electromagnetic coil 10 does not form the electrical insulating layer 50 on the surface of the frameless coil 30 by simply injecting the liquid thermosetting resin 70 into the storage groove 24 of the coil housing 20.

[0105] Specifically, the frameless coil 30, which is entirely covered by the elastic covering body 40, is received in the receiving groove 24 of the coil housing 20, and a liquid thermosetting resin 70 is injected into the receiving groove 24. Thus, the covering body 40 can be impregnated with the thermosetting resin 70. Thereafter, the impregnated thermosetting resin 70 is heated to solidify, so that the electrical insulating layer 50 can be formed on the surface of the frameless coil 30. The covering body 40 constitutes a base material for forming and maintaining the electrical insulating layer 50. Figure 1 As shown, the electrical insulating layer 50 is formed only inside and on the surface of the coating 40 by impregnation, and electrically insulates the side walls 21, 22 (slot side walls 21, 22) that divide the storage slot 24 of the coil housing 20 from the surface of the frameless coil 30. By eliminating the coil frame, the electromagnetic coil 10 can be miniaturized and lightweight.

[0106] Furthermore, the thermosetting resin 70 can be impregnated only in the interior and surface of the coating 40 serving as the base material. Therefore, the thickness of the thermosetting resin 70 can be relatively thin. For example, the portion of the electrical insulating layer 50 on the side of the opening 24a of the storage groove 24 is a structure having only the thickness of the coating 40 (including the approximate thickness), that is, it is composed only of the electrically insulating thermosetting resin impregnated in the coating 40. It is not necessary to fill the entire storage groove 24 with the electrically insulating thermosetting resin 70. The groove width Gw and the groove depth Gd of the storage groove 24 can be set small. As a result, the electromagnetic coil 10 can be miniaturized and lightweight.

[0107] In addition, the covering body 40 has elasticity and is therefore less likely to wrinkle when covering the frameless coil 30. Therefore, the covering body 40 can be uniformly impregnated with the thermosetting resin 70, so that the electrical insulating layer 50 of uniform thickness can be obtained.

[0108] Next, a structure in which the electromagnetic coil 10 having the above structure (including the electromagnetic coil 10 obtained by the above manufacturing method) is provided in the electromagnetic clutch 100 will be described.

[0109] like Fig.11 As shown, the electromagnetic clutch 100 is provided in a gas compressor 110 which is one of the components of the refrigeration cycle of the vehicle air conditioner and is a mechanical element component that transmits or cuts off power to the gas compressor 110. The gas compressor 110 includes a rotating shaft 112 rotatably supported by a housing 111 and a compression mechanism (not shown) housed in the housing 111 and driven by the rotating shaft 112.

[0110] The electromagnetic clutch 100 includes the electromagnetic coil 10 , a first rotating body 101 on the driving side made of a magnetic material, a second rotating body 102 on the driven side rotatable relative to the first rotating body 101 , and an armature plate 103 connected to the second rotating body 102 .

[0111] The second rotating body 102 is mounted in a manner that restricts relative rotation with respect to a rotating shaft 112 extending outward from the housing 111 .

[0112] The first rotating body 101 is an annular member based on the center line CL of the rotating shaft 112, is located radially outward from the rotating shaft 112, and is rotatably supported by the housing 111. The first rotating body 101 can receive power from an external rotating power source such as an engine or a motor, and is composed of, for example, a pulley.

[0113] The armature plate 103 is made of a magnetic material, fixed to the second rotating body 102, and arranged to face the side end surface 101a (friction surface 101a) of the first rotating body 101 with a gap 104. Specifically, the armature plate 103 has a friction surface 105 facing the side end surface 101a of the first rotating body 101.

[0114] The first rotating body 101 has a storage space 106 for storing the electromagnetic coil 10. The storage space 106 is an annular space based on the center line CL of the rotating shaft 112, and is open to the opposite side relative to the side end surface 101a. The coil housing 20 of the electromagnetic coil 10 is stored with a certain gap 107 relative to the storage space 106. Therefore, the first rotating body 101 does not slide in contact with the coil housing 20 and can rotate. The bottom wall 23 of the coil housing 20 of the electromagnetic coil 10 is fixed to the housing 111 by the fixing plate 108.

[0115] The above description of the electromagnetic clutch 100 including the electromagnetic coil 10 is summarized as follows.

[0116] like Fig.11 As shown, the electromagnetic clutch 100 has:

[0117] The electromagnetic coil 10;

[0118] A first rotating body 101 on the driving side, which is made of a magnetic material;

[0119] The second rotating body 102 on the passive side can rotate relative to the first rotating body 101;

[0120] The armature plate 103 is made of a magnetic material, is connected to the second rotating body 102 , and is disposed opposite to the side end surface 101 a of the first rotating body 101 with a gap 104 therebetween.

[0121] The electromagnetic coil 10 is accommodated inside the first rotating body 101 so that a magnetic circuit passing through the first rotating body 101 and the armature plate 103 can be formed by energizing the frameless coil 30 and an attraction force can be generated to electromagnetically attract the armature plate 103 to the first rotating body 101 .

[0122] By providing the small and lightweight electromagnetic coil 10 , it is possible to achieve a reduction in size and weight of the electromagnetic clutch 100 .

[0123] It should be noted that the electromagnetic coil 10 , the electromagnetic clutch 100 including the electromagnetic coil 10 , and the method for manufacturing the electromagnetic coil 10 of the present invention are not limited to the embodiments as long as they can achieve the functions and effects of the present invention.

[0124] For example, the electromagnetic coil 10 of the present invention (including the electromagnetic coil 10 obtained by the manufacturing method of the present invention) is not limited to the structure provided in the electromagnetic clutch 100, and can be provided in various electromagnetic devices such as electromagnetic brakes to exert the same effect as the electromagnetic clutch 100.

[0125] In addition, the coating step of the method for manufacturing the electromagnetic coil 10 (see Figure 6A) As long as the entire frameless coil 30 can be covered by the covering body 40, it is optional whether to also cover the connecting end portions 31a, 31a and the component connecting portions 31b, 31b. For example, the connection process can be performed first (refer to Figure 6 B), and then the coating process is performed simultaneously (refer to Figure 6 A) and additional coating process (refer to Figure 6 C) By doing so, Figure 6 In the coating process shown in A, the entire frameless coil 30 can also be coated. Figure 6 The connection end portions 31a, 31a and the component connection portions 31b, 31b shown in C are covered.

[0126] Industrial Applicability

[0127] The electromagnetic coil 10 of the present invention (including the electromagnetic coil 10 of the present invention) and the electromagnetic clutch 100 including the electromagnetic coil 10 are suitable for use in a compressor of a vehicle air conditioner.

[0128] Description of Reference Numerals

[0129] 10. Electromagnetic coil;

[0130] 20 coil housing;

[0131] 21 inner peripheral side wall;

[0132] 22 side wall on the peripheral side;

[0133] 24 storage slots;

[0134] 26 inner surface (surface on the storage groove side);

[0135] 27 recess;

[0136] 30 No skeleton coil;

[0137] 31 coil winding wire;

[0138] 40 Encapsulation;

[0139] 41 belts;

[0140] 50 electrical insulation layer (thermosetting resin);

[0141] 70 Liquid thermosetting resin;

[0142] 100 Electromagnetic clutch;

[0143] 101 a first rotating body on the driving side;

[0144] 101a side end surface;

[0145] 102 a second rotating body on the passive side;

[0146] 103 armature plate;

[0147] 104 interval;

[0148] 110 Gas compressor.

Claims

1. An electromagnetic coil (10), characterized in that: Include: A magnetic coil housing (20) having an annular receiving groove (24); A frameless coil (30) is directly received in the receiving slot (24); A covering body (40) having elasticity and resin impregnation properties, covering the entire frameless coil (30); The electrical insulating layer (50) is composed of an electrically insulating thermosetting resin impregnated in the covering body (40) and covers the surface of the frameless coil (30).

2. The electromagnetic coil according to claim 1, The covering body (40) is made of knitted fabric.

3. The electromagnetic coil according to claim 1, The covering body (40) is made of stretchable nonwoven fabric.

4. The electromagnetic coil according to claim 1, The covering body (40) is composed of a tape (41) that can be wound around the frameless coil (30).

5. The electromagnetic coil according to claim 4, characterized in that The tape (41) is wound into at least two layers relative to the frameless coil (30).

6. The electromagnetic coil according to claim 1, The frameless coil (30) is fixed to the storage groove (24) by the thermosetting resin.

7. The electromagnetic coil according to claim 6, The coil housing (20) has a recess (27) recessed from a side wall (26) that divides the storage groove (24). At least a portion of the thermosetting resin is buried in the recess (27).

8. An electromagnetic clutch (100), characterized in that: have: The electromagnetic coil (10) according to any one of claims 1 to 7; A first rotating body (101) on the driving side, which is made of magnetic material; A second rotating body (102) on the passive side, which is capable of relatively rotating relative to the first rotating body (101); an armature plate (103) made of a magnetic material, connected to the second rotating body (102), and arranged opposite to the side end surface (101a) of the first rotating body (101) with a gap (104); The electromagnetic coil (10) is housed inside the first rotating body (101) in such a manner that, by energizing the frameless coil (30), a magnetic circuit is formed through the first rotating body (101) and the armature plate (103) and an attraction force is generated that causes the armature plate (103) to be electromagnetically attracted to the first rotating body (101).

9. A method for manufacturing an electromagnetic coil (10), the electromagnetic coil (10) comprising: A magnetic coil housing (20) having an annular receiving groove (24); A frameless coil (30) is directly received in the receiving slot (24); A covering body (40) having elasticity and resin impregnation properties, covering the entire frameless coil (30); An electrical insulating layer (50), which is composed of an electrically insulating thermosetting resin impregnated in the coating (40) and covers the surface of the frameless coil (30); The manufacturing method of the electromagnetic coil (10) is characterized by comprising: A step of preparing the frameless coil (30); Thereafter, a step of using the covering body (40) to cover the entire frameless coil (30); Thereafter, a step of storing the frameless coil (30) covered by the covering body (40) in the storage groove (24); Thereafter, a step of injecting a liquid thermosetting resin (70) having electrical insulation properties into the storage groove (24) to impregnate the coating (40) with the liquid thermosetting resin (70); Thereafter, the step of forming the electrical insulating layer (50) is performed by heating the liquid thermosetting resin (70) impregnated in the coating (40) to cure the resin.

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