JP2010114998A - Coil unit and electromagnetic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil unit that ensures the gap between a coil and a core properly from the viewpoint of ensuring heat dissipation properties and preventing discharge, and to provide the electromagnetic component. <P>SOLUTION: The coil unit 20 includes a coil 10, and a partial molding 15 which is molded integrally with the coil 10. A split core 51 is attached to the coil unit 20 by fitting the partial molding 15 and teeth 51b. The gap Sp between the coil unit 20 and the split core 51 is ensured in a proper range by the partial molding 15. In other words, the entire gap Sp can be reliably filled with resin during whole molding. Since the air gap between the coil 10 and the split core 51 can be eliminated, heat dissipation properties are ensured and generation of partial discharge is controlled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coil unit and an electromagnetic component arranged in a motor, a generator, a reactor, or the like.

  A stator (stator), a reactor, and a transformer of a motor or a generator are configured by winding a coil around a core. In the stators of Patent Documents 1 and 2, the coil is wound around the core via an insulator. And in order to dissipate the heat which generate | occur | produces with a coil, the whole stator is molded with resin.

In Patent Document 3, an insulator made of a thermosetting resin is insert-molded in a core or a coil. Then, the stator is formed by combining the core and the coil, and the entire stator is molded with resin.
JP 59-222005 JP-A-60-32534 JP 2008-160938 A

  However, in Patent Documents 1 and 2, the gap between the core and the insulator or the gap between the insulator and the core is narrow. Therefore, it is difficult to sufficiently fill the gap with mold resin when the entire molding is performed. For this reason, there is a possibility that the heat dissipation is deteriorated and the insulation is deteriorated due to partial discharge.

On the other hand, in Patent Document 3, there is always a gap between the insulator and either the core or the coil. Therefore, it is difficult to fill the gap with the molding resin when the entire molding is performed. For this reason, there are the same problems as in Patent Documents 1 and 2.
In particular, a resin mixed with a filler for the purpose of increasing the thermal conductivity has poor fluidity, so that the above-described problems appear remarkably.

  The objective of this invention is providing the coil unit which can ensure appropriately the distance of a coil and a core from a viewpoint of heat dissipation ensuring and discharge prevention, and an electromagnetic component using the same.

The coil unit of the present invention is wound in a shape surrounding the periphery of a rectangular core. The coil unit includes a rectangular tube-shaped coil having a pair of first and second side portions and third and fourth side portions that face each other. The first side portion and the second side portion are portions that generate a main magnetic current in the core. And the partial mold part shape | molded integrally with the coil is provided in the 3rd side part and 4th side part of a coil.
When the core is disposed in a motor or a generator, the third and fourth side portions are coil end portions of the coil.
The partial mold portion is generally made of a resin, but an inorganic insulator or the like may be used.

With this structure, the coils are bundled by the partial mold portion so as not to be separated. When the core is attached to the coil, the partial mold portion is interposed between the coil and the core in the coil unit. Therefore, it becomes easy to keep the distance between the coil and the core within the range in which the mold resin is filled. When the gap is filled with mold resin, heat dissipation can be secured. In addition, since there is no gap between the core and the coil unit, occurrence of partial discharge is also suppressed.
On the other hand, the presence of the partial mold portion causes the third and fourth side portions of the coil to be separated from the core. However, since the third and fourth side portions are not portions that cause the main magnetic current in the core, the function of the coil unit is hardly impaired.

  It is preferable that the partial mold part has the positioning part which determines the relative position of a core and a coil. Thereby, it becomes possible to ensure the distance of all the gaps between the core and the coil appropriately.

The coil is preferably provided such that the distance between the first and second side portions with the core is within a predetermined range. This makes it possible to keep the distance between the first and second side portions that cause the main magnetic current in the core and the core within an appropriate range.
The predetermined range is a distance at which the entire mold part is sufficiently filled with resin and heat dissipation is ensured. When a resin to which a filler is not added is used, the fluidity is good, so that it is easy to fill the resin even in a narrow gap. However, in order to improve heat dissipation, it is preferable to increase the thermal conductivity by adding a filler even if the fluidity deteriorates. Moreover, even if the distance between the coil and the core is too large, the heat dissipation is deteriorated.
The predetermined range is, for example, about 0.3 mm to 1.0 mm.

  The electromagnetic component of the present invention is provided with an entire mold portion that fills a gap between the coil unit and a core disposed inside the coil unit.

Thereby, the electromagnetic component which can ensure the distance of a coil and a core appropriately from a viewpoint of heat dissipation ensuring and discharge prevention is obtained.
Electromagnetic components include motors and generators (stator), reactors, and transformers.

  According to the coil unit or the electromagnetic component of the present invention, the distance between the coil and the core can be appropriately ensured. Therefore, partial discharge can be suppressed while ensuring heat dissipation.

(Embodiment 1)
−Structure of coil unit−
FIGS. 1A and 1B are a perspective view and a cross-sectional view taken along line Ib-Ib, respectively, showing a coil unit 20 according to Embodiment 1 of the present invention in order. The coil knit 20 of the present embodiment is arranged on a stator (stator) of a motor. In the figure, the x direction is the rotor side direction (radial direction), the y direction is the coil side direction (circumferential direction), and the z direction is the coil end direction (axial direction).

As shown in the figure, the coil unit 20 includes a coil 10 wound in a shape surrounding a core and a partial mold portion 15.
The partial mold portion 15 is formed integrally with the coil 10 in the coil end portion 10 a of the coil 10. For example, the coil end portion 10a of the coil 10 is attached to a part of the die cavity of the mold, and resin molding is performed. This method is generally called outsert molding.

  Here, the coil end portion 10a of the coil 10 is a portion parallel to the xy plane shown in the lower right of FIG. The coil side portion 10b of the coil 10 is a portion parallel to the xz plane shown in the lower right of FIG. The coil side portion 10b is a first side portion and a second side portion that generate a main magnetic current in the core. The coil end portion 10a is a side portion that intersects the coil side portion 10b that is the first and second side portions.

In the present embodiment, the coil 10 is obtained by winding the rectangular wire 11 in an edgewise manner, but is not limited thereto. The coil 10 of the present invention can use a coil wire having an arbitrary cross-sectional shape such as a circle, rectangle, or polygon.
For example, the coil 10 may be one in which a flat wire 11 is wound flatwise. Further, instead of the flat wire 11, a round wire, a square wire, a polygonal wire or the like may be wound in multiple layers.
Note that both ends of the coil 10 project to the coil end side to form external terminals 13 and 14.

  Although not shown, each rectangular wire 11 has a copper wire having a substantially rectangular cross section and a coating film covering the copper wire. The skin covering film is made of an imide resin represented by polyimide, polyamideimide, polyesterimide and the like.

As the partial mold part 15, resins such as unsaturated polyester resin (BMC), PPS resin (polyphenylene sulfide), LCP resin (liquid crystal polymer), epoxy resin, and urethane can be used. However, it is not necessarily limited to resin, and an inorganic insulator may be used.
In particular, it is preferable to use an unsaturated polyester resin as the resin constituting the partial mold portion 15. This is because the unsaturated polyester resin has a high molding accuracy because the molding shrinkage rate is almost zero when transfer molding is performed.

-Stator structure-
FIG. 2 is a perspective view showing a state in which the split core 51 is attached to the coil unit 20.
The split core 51 has a yoke part 51 a and a teeth part 51 b that protrudes from the yoke part 51 to the rotor side. In the present embodiment, the split core 51 has a laminated steel plate structure in which a large number of magnetic steel plates are laminated with an insulating layer interposed therebetween. However, you may employ | adopt what is called a powder core structure formed by compression-molding the magnetic powder which has an insulating film.

The tooth part 51 b of the split core 51 is inserted inside the coil 10. At this time, the partial mold part 15 and the teeth part 51b are fitted together. As described above, since the unsaturated polyester resin has a molding shrinkage rate of approximately 0, an intermediate fit is possible. Thereby, the relative positional relationship between the coil unit 20 and the split core 51 is substantially determined.
At this time, it is preferable to set the clearance Sp between the coil unit 20 and the split core 51 on the coil side side within a predetermined range of 0.3 mm to 1.0 mm.

  Thereafter, the entire coil unit 20 and the split core 51 are molded to form a split stator. If the dimension of the gap Sp is set within the predetermined range, the resin is sufficiently filled in the gap Sp, and heat dissipation is also ensured.

  3A to 3C are cross-sectional views showing steps until the split stator 50A is formed. 3A to 3C show changes in the structure in the cross section (cross section parallel to the xy plane) taken along line III-III shown in FIG.

  FIG. 3A is a cross-sectional view of the coil unit 20. The opening 33 of the coil 10 of the coil unit 20 is sufficiently larger than the outer shape of the tooth portion 51 b of the split core 51.

  FIG. 3B is a cross-sectional view showing a state where the tooth portion 51 b is inserted into the opening 33 of the coil 10. As shown in the figure, a gap Sp exists between the coil 10 and the tooth portion 51b.

  FIG. 3C is a cross-sectional view when the divided stator 50A is assembled. In the present embodiment, resin is injected into the gap Sp between the coil 10 and the tooth portion 51 b to form the entire mold portion 30. As the resin of the entire mold part 30, epoxy resin, BMC resin (unsaturated polyester resin), urethane or the like is used. It is preferable that an insulating filler is added to the entire mold part 30. By adding the inorganic filler, the thermal conductivity of the entire mold part 30 is improved.

FIG. 4 is a cross-sectional view showing a schematic structure of the stator 50 in which the divided stators 50A are combined in an annular shape. A rotor (not shown) provided with a permanent magnet is disposed inside the stator 50.
Instead of the split core 50, an annular integrated stator that is continuously connected by a yoke portion may be used. In that case, a plurality of teeth portions protrude from the stator to the rotor side.

As a procedure for assembling the stator 50, the following procedure is suitable. First, the coil unit 20 and the split core 51 are separately prepared. Next, the divided stator 50A is assembled from the coil unit 20 and the divided core 51 (see FIG. 3C). In that case, the whole mold which embeds resin in gap Sp between teeth part 51b and coil 10 is performed.
Each divided stator 50A formed as described above is assembled in an annular shape. Thereafter, the stator 50 is assembled by being enclosed from the outside using a ring member or the like (not shown).

  According to the coil unit 20 of the present embodiment, the following effects can be obtained. First, the partial mold part 15 can prevent the coil 10 from being deformed by a springback or the like. And since the coils 10 can be closely adhered, the space factor is improved.

  Further, when the stator is assembled, the partial mold portion 15 is interposed between the coil 10 and the core (the teeth portion 51b) (see FIG. 3B). Thereby, the distance between the coil 10 and the teeth part 51b is maintained appropriately. That is, the entire mold part 30 can be sufficiently filled with the mold resin. Therefore, the air gap can be eliminated and heat dissipation can be maintained high. In addition, partial discharge due to the presence of voids can be prevented.

  In the present embodiment, the gap Sp is set to a predetermined range of 0.3 mm to 0.5 mm, but is not limited to this. Even if the gap Sp is smaller than 0.3 mm, if the filler is not added or a small amount of resin is used, the resin can be sufficiently filled in the gap Sp. However, in order to improve heat dissipation, it is preferable to increase the thermal conductivity by adding a filler even if the fluidity deteriorates. Therefore, the gap Sp is preferably 0.3 mm or more. On the other hand, if the gap Sp exceeds 0.5 mm, the heat dissipation is deteriorated. Therefore, it is preferable that the clearance Sp is set to a predetermined range of 0.3 mm to 0.5 mm.

Even if the gap Sp is sufficiently filled with resin, if the gap Sp is small, partial discharge may occur through the resin. Generally, when the distance between the core and the coil unit is smaller than 0.1 mm, partial discharge tends to occur.
However, the insulation distance for preventing partial discharge differs depending on the voltage between the coil and the core and the dielectric constant of the member disposed between them. Therefore, the lower limit of the predetermined range in the present invention is preferably an insulation distance determined by the structure of the stator. In the present embodiment, since the lower limit value of the predetermined range is 0.3 mm, partial discharge through the resin can also be suppressed.

  The space between the coil end portion 10a of the coil 10 and the tooth portion 51b is widened by the partial mold portion 15a. However, since the amount of heat generated in the coil end portion 10a is small, there is almost no influence on the heat dissipation. That is, if the distance between the coil 10 and the tooth portion 51b in the coil side portion is appropriate, heat can be effectively released.

(Modification of Embodiment 1)
FIG. 5 is a perspective view showing a state where the split core 51 is attached to the coil unit 20 according to the modification of the first embodiment. In this figure, the same members as those shown in FIG. 1 and FIG.

In the coil unit 20 of the present modification, engagement convex portions 15 a are provided at two locations above and below the partial mold portion 15. On the other hand, an engagement groove 51c that engages with the engagement convex portion 15a is formed in the coil end portion of the tooth portion 51b of the split core 51. The engaging protrusion 15a and the engaging groove 51c are formed along the axial direction (x direction) of the motor. The engagement convex portion 15a and the engagement groove 51c function as a row positioning portion for relative positioning of the coil unit 20 and the split core 51 in the circumferential direction (y direction).
The structure of the positioning portion is not necessarily limited to this structure, and a well-known and usual engagement structure can be adopted.

  The engagement convex portion 15a and the engagement groove 51c define a gap Sp between the coil 10 and the tooth portion 51b on the coil side side. Therefore, the gap Sp can be reliably set within the predetermined range, and the effects of the first embodiment can be obtained more reliably.

(Embodiment 2)
FIG. 6 is an exploded perspective view showing a part of the reactor device according to the second embodiment. FIG. 7 is a perspective view showing a schematic configuration of reactor device 70 according to the second embodiment.
The reactor device 70 is configured by housing a reactor 60 (electromagnetic component) in a case 71. The reactor 60 includes a core 61 and a coil unit 62 that surrounds the core 61 in an annular shape.

  The core 61 is mainly composed of a soft magnetic material, which is also called a high magnetic permeability material, or an electromagnetic steel plate, and the planar shape is substantially a track shape. Although not shown, the core 61 has a plurality of partial cores connected via a gap spacer made of a nonmagnetic and insulating material such as ceramics, glass, glass epoxy or the like. Although not clearly shown in FIG. 6, the core 61 is divided into a portion corresponding to the linear portion of the track and a semicircular portion corresponding to the corner portion.

  The coil unit 62 includes an annular portion 62a (coil portion) surrounding the two straight portions of the core 61, a connection portion 62b, and a terminal 62c. The coil wire of the coil unit 62 is almost entirely covered with an insulating film, and only the terminal 62c is exposed from the insulating film. When energized, an alternating current flows from one terminal 62c to the other terminal 62c through the annular portion 62b and the connecting portion 62b.

In addition, partial mold portions 65 are provided on a pair of opposite side portions of the annular portion 62a of the coil unit 62, respectively. The side portion on which the partial molding portion 65 is provided corresponds to the coil end portion 10a (third and fourth side portions) of the coil 10 in the first embodiment. The side portions that generate the main magnetic current in the core 61 are the first and second side portions that are in contact with the inner side surface and the outer side surface of the track-shaped core 61, respectively. The third and fourth side portions intersect the first and second side portions.
However, the lower partial mold portion 65 is provided at a position where it cannot be seen in FIG. The partial mold portion 65 is formed integrally with the annular portion 62 a of the coil unit 62. As the material of the partial mold part 65, the same resin as that of the partial mold part 15 in the first embodiment can be used.

  At the time of assembly, the coil unit 62 is mounted around the straight portion of the core 61. At this time, the partial mold part 65 and the linear part of the core 61 are fitted together. Thereafter, after the reactor 60 is accommodated in the middle case 66, the middle case 66 and the reactor 60 are accommodated in the case 71.

  In a general process, the entire mold (potting) is then performed to fill the entire gap of the case 71 with resin. At this time, almost the entire reactor 60 excluding the terminal 62c and a portion adjacent to the terminal 62c is sealed in the resin. The resin is also filled in the gap between the annular portion 62 a of the coil unit 62 and the core 61.

Also according to the first embodiment, by providing the partial mold portion 65, the same effect as in the first embodiment can be exhibited.
That is, the partial mold part 65 can prevent the coil from being deformed by a springback or the like. Further, since the partial mold portion 65 is interposed between the coil and the core 61, the distance between the coil and the core 61 is properly maintained. That is, the resin can be sufficiently filled between the coil and the core 61 during the entire molding. Therefore, the air gap can be eliminated and heat dissipation can be maintained high. In addition, partial discharge due to the presence of voids can be prevented.

  Also in the present embodiment, a positioning portion can be provided in the partial mold portion 65 and the core 61 as in the modification of the first embodiment. For example, an engaging projection and an engaging groove that engage with each other can be formed.

(Other embodiments)
In the first embodiment, the salient pole structure in which the teeth 51b protrude from the yoke 51a is adopted as the core structure. However, the core structure in the stator is not limited to such an embodiment, and other structures can be adopted.

  In the said Embodiment 1, 2, the example which used the coil unit as a part of a rotary motor or a reactor was demonstrated. However, the coil unit of the present invention can also be used for linear motors, generators, transformers, and the like. That is, the electromagnetic component of the present invention can be applied to a general apparatus having a coil and a core.

  The structure of the embodiment of the present invention disclosed above is merely an example, and the scope of the present invention is not limited to the scope of these descriptions. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  The coil unit and electromagnetic component of the present invention can be used for a linear motor, a generator, a reactor, a transformer, and the like. These devices are arranged in hybrid vehicles, electric vehicles, fuel cell vehicles, robots, and various industrial equipment.

(A), (b) is the perspective view which shows the coil unit which concerns on Embodiment 1 of this invention in order, and sectional drawing in the Ib-Ib line. It is a perspective view which shows the state which mounted | wore the division | segmentation core with the coil unit which concerns on Embodiment 1. FIG. (A)-(c) is a cross-sectional view which shows the process until a division | segmentation stator is formed. It is sectional drawing which shows the schematic structure of the stator which combined the division | segmentation stator in cyclic | annular form. It is a perspective view which shows the state which mounted | wore with the split core to the coil unit which concerns on the modification of Embodiment 1. FIG. It is a perspective view which decomposes | disassembles and shows a part of reactor device which concerns on Embodiment 2. FIG. It is a perspective view which shows schematic structure of the reactor apparatus which concerns on Embodiment 2. FIG.

Explanation of symbols

Sp gap 10 coil 10a coil end part 10b coil side part 11 flat wire 13, 14 terminal 15 partial mold part 15a engagement convex part 20 coil unit 21, 22 terminal 30 whole mold part 33 opening part 50 stator 50A division stator 51 division core 51a Yoke part 51b Teeth part 51c Engaging groove 60 Reactor 61 Core 62 Coil unit 62a Annular part (coil)
62b Connection portion 62c Terminal 65 Partial mold portion 66 Middle case 70 Reactor device 71 Case

Claims (4)

A first side wound around a rectangular core and generating a main magnetic current in the core, a second side facing the first side, and a third side intersecting the first and second sides A rectangular tube-shaped coil having a portion and a fourth side portion facing the portion,
A partial mold part provided on the third side part and the fourth side part of the coil and molded integrally with the coil;
Coil unit equipped with. The coil unit according to claim 1, wherein
The partial mold part is a coil unit having a positioning part for determining a relative position between the core and the coil. The coil unit according to claim 1 or 2,
The said coil is a coil unit provided so that the distance with the core in the said 1st side part and a 2nd side part may be settled in a predetermined range. The coil unit according to any one of claims 1 to 3,
A core disposed inside the coil unit;
An entire mold part made of a resin filling at least the gap between the coil unit and the core;
With electromagnetic parts.

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