JP2011009660A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor in which a radiation fin is fixed more simply by using members that constitute the reactor.SOLUTION: The reactor includes: an annular circular magnetic core 200 having a pair of coil-wound parts 220; and a pair of coil elements 110a, 110b that are disposed on outer peripheries of both the coil-wound parts 220. The reactor further includes a radiation fin 300 and a resin part 120. In the resin part 120, the magnetic core 200, at least one of the coil elements 110a, 110b, and the radiation fin 300 are integrally molded. Since the radiation fin 300 is integrally molded by the resin part 120, at least one of the coil 110 and magnetic core 200 is protected by the resin part 120, and the radiation fin 300 is readily held to at least one of the coil 110 and magnetic core 200.

Description

  The present invention relates to a reactor used in a DC-DC converter for an electric vehicle such as a hybrid vehicle, and more particularly to a reactor excellent in heat dissipation and assembly workability.

  2. Description of the Related Art In recent years, converters that perform voltage step-up / step-down are used in hybrid vehicles that are becoming popular, and a reactor described in Patent Document 1 is known as one of the components of the converter.

  The reactor includes an annular magnetic core (iron core) and a coil disposed on the outer periphery of a part of the core. This coil has a pair of coil elements arranged in parallel. And a cylindrical cover is formed so that the outer side of both these coil elements may be covered collectively, and the several fin for improving the heat dissipation of a reactor is provided in the outer periphery of this cover. The cover having fins is fixed by filling the gap between the coil and the cover with resin, and the gap between the core and the coil is also filled with resin.

Japanese Patent Laid-Open No. 8-222442 FIG.

  However, in the above reactor, in order to fix the fin to the coil, it is necessary to fill the gap between the cover and the coil with resin, and to fix the coil to the core, the gap between the core and the coil is required. It is necessary to fill the gap with resin. That is, it is necessary to individually fill the inner peripheral side and the outer peripheral side of the coil with resin, and the assembly work of the reactor becomes complicated. In particular, there is often a certain gap between the turns of the coil, and the coil itself expands and contracts. Therefore, handling the coil that expands and contracts when the reactor is assembled makes the assembly work more difficult.

  In addition, since resin exists only on the inner and outer peripheral sides of the coil, it is necessary to provide a cover and a case for covering the core separately in order to protect the components other than the coil, such as the core. Further, the assembly work becomes complicated.

  This invention is made | formed in view of said situation, and the one of the objectives is using the structural member of a reactor, and providing a reactor which can fix a radiation fin more simply.

  The reactor of this invention is equipped with the annular magnetic core which has a pair of coil winding part, and a pair of coil element arrange | positioned on the outer periphery of both coil winding parts. And this reactor is equipped with the resin part which integrally molds a radiation fin and at least one of the said core and a coil element, and a radiation fin.

  According to this configuration, since the radiating fin is integrally formed with the resin portion, at least one of the coil and the core is protected by the resin portion, and the radiating fin is easily held with respect to at least one of the coil and the core. Can do. Therefore, the assembly workability of the reactor is excellent.

  As one form of the reactor of this invention, providing a radiation fin in the side surface of each coil element is mentioned.

  If it is a side surface of each coil element, it is relatively easy to project the heat radiating fins and hardly interfere with other peripheral devices. Therefore, it is possible to construct a reactor that can sufficiently exhibit the effect of improving the heat radiating characteristics by the heat radiating fins. Moreover, if a heat radiating fin is provided on the side surface of the coil element, it is easy to configure a mold for molding the resin portion, and it is easy to take out the molded body from the mold.

  As one form of the reactor of this invention, you may comprise the said thermal radiation fin by a part of said resin part.

  According to this configuration, the heat radiating fins can be formed at the same time when the resin portion is molded. In addition, it is not necessary to configure the radiating fins with a material independent of the resin portion, and the number of parts can be reduced.

  As one form of the reactor of this invention, it is mentioned to comprise a radiation fin with a nonmetallic material.

  By using a non-metallic material for the heat dissipating fin, it is possible to easily insulate the heat dissipating fin from the coil.

  As one form of the reactor of this invention, it is mentioned that a radiation fin is comprised with a metal material.

  If the radiating fin is a metal material, there are wide choices of materials having high heat conduction characteristics, and the radiating fin can easily have high radiating characteristics. As a result, a reactor having excellent heat dissipation characteristics can be constructed. Further, the heat dissipating fins can have high toughness and can be made difficult to be damaged.

  As one form of the reactor of this invention, the said resin part may be provided with the inner side resin part holding the shape of a coil, and the outer side resin part formed in the outer side of an inner side resin part. In that case, it is mentioned that the said radiation fin is integrally molded by the inner side resin part.

  According to this configuration, the coil can be handled as a member that does not expand and contract by holding the shape of the coil with the inner resin portion. Further, by molding the heat radiation fin integrally with the inner resin portion, it can be handled as a component combined with the coil and the heat radiation fin. Therefore, the assembly workability of the reactor is excellent.

  As one form of the reactor of this invention, the said resin part may be provided with the inner side resin part holding the shape of a coil, and the outer side resin part formed in the outer side of an inner side resin part. In that case, it is mentioned that the said radiation fin is integrally shape | molded by the outer side resin part.

  According to this configuration, the coil can be handled as a member that does not expand and contract by holding the shape of the coil with the inner resin portion. Also, by molding the heat radiation fins integrally with the outer resin part, the heat radiation fins can be fixed to one or both of the coil and the core, and the object to which the heat radiation fins are attached can have a wide degree of freedom. it can.

  According to the reactor of the present invention, since the radiating fins are integrally formed with the resin portion, at least one of the coil and the core is protected by the resin portion, and the radiating fin is easily fixed to at least one of the coil and the core. It can be carried out.

1 is an exploded perspective view of a reactor of the present invention according to Embodiment 1. FIG. It is a perspective view of the coil used for the reactor of Embodiment 1. FIG. It is a partial notch perspective view of the reactor of this invention which concerns on Embodiment 2. FIG. FIG. 10 is a schematic explanatory diagram illustrating a method for manufacturing a reactor according to a third embodiment.

[Embodiment 1]
A reactor according to the present invention in which a coil and a radiating fin are integrally formed with a resin portion will be described with reference to FIGS. In each figure, the same reference numerals indicate the same items.

[overall structure]
As shown in FIG. 1, the reactor 1 includes a coil molded body 100 and a magnetic core 200 combined with the coil molded body 100. The coil molded body 100 is configured by integrating the coil 110 and the heat radiating fins 300 with the resin portion 120. For example, the reactor 1 is used by being directly installed on a metal (typically aluminum) cooling base (not shown) having a refrigerant circulation path therein. Hereinafter, each component will be described in more detail.

[Coil molding]
(coil)
As shown in FIG. 2, the coil 110 has a pair of coil elements 110a and 110b formed in a rectangular tube shape by spirally winding one continuous winding 110w. Both coil elements 110a and 110b are formed side by side so that their axial directions are parallel to each other. The winding 110w is preferably a coated wire having an insulating coating layer on the outer periphery of the conductor. Here, a coated rectangular wire is used in which the conductor is made of a copper rectangular wire and the insulating coating layer is made of enamel. Both coil elements 110a and 110b are formed by edgewise winding the covered rectangular wire, and are connected by a winding part 110r formed by folding a part of the winding 110w into a hairpin shape. The winding 110w can have various shapes such as a circular shape and a polygonal shape, in addition to the conductor made of a rectangular wire.

  Both end portions of the winding 110w forming the coil 110 are appropriately extended from the turn forming portion and pulled out of the resin portion 120 (FIG. 1), and the conductor portion exposed by peeling off the insulating coating layer, A terminal member (not shown) made of a conductive material is connected. An external device (not shown) such as a power source for supplying power is connected to the coil 110 via the terminal member. For connection between the conductor portion of the winding 110w and the terminal member, welding such as TIG welding can be used.

(Heat radiation fin)
The radiating fin 300 is a member that efficiently radiates heat generated by the excitation of the coil 110. In this example, the heat radiating fins 300 made in advance using a material different from the resin part 120 are used.

  As a material of the radiation fin 300, a material having excellent thermal conductivity is preferable. If it is a metal material, copper, a copper alloy, aluminum, and an aluminum alloy can be used suitably. As long as it is a non-metallic material, at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, and silicon carbide can be suitably used. If it is a metal material, acquisition of a material and the process of the radiation fin 300 are easy. Further, if it is a non-metallic material, it is possible to easily ensure insulation from the coil 110 regardless of the insulation coating of the winding 110w and the thickness of the resin portion 120 described later. In this example, the heat radiation fin 300 is made of alumina. In addition, the radiating fin 300 may be formed of a composite material in which ceramic particles having high thermal conductivity are dispersed in a metal matrix. For example, a composite material in which SiC particles are dispersed in an aluminum alloy or a magnesium alloy can be given.

  The shape of the heat dissipating fin 300 is not particularly limited as long as its surface area can be secured wider. As a form for securing the surface area, a shape having a plurality of protrusions is suitable. This projection can be used in various forms such as a rod shape, a strip shape, and a plate shape. The size and number of protrusions may be selected as appropriate. In this example, a plurality of protrusions 320 having a triangular cross section extending in the axial direction of the coil are arranged on a rectangular plate-like substrate 310 in the form of heat radiation fins 300 arranged in parallel in the height direction of the coil 110.

  It is preferable that the radiating fin 300 is installed at a location where the reactor 1 is likely to generate heat and in the vicinity thereof, where it is difficult to interfere with other components of the reactor 1 and peripheral devices of the reactor 1. In this example, the radiating fins 300 are provided on both outer side surfaces of the coil 110. Of course, other than that, the radiating fin 300 may be installed on the upper surface of the coil 110 or the like.

(Resin part)
The resin part 120 retains the coil 110 and holds the coil 110 and the radiation fin 300 integrally.

  The portion where the coil 110 is covered with the resin portion 120 is only required to retain the shape of the coil 110 to the extent that the expansion and contraction of the coil 110 can be avoided and to hold the radiating fin 300 integrally with the coil 110, excluding the end of the winding 110w. The entire surface of the coil 110 may be used, or a part of the coil 110 may be used. The part where the coil 110 is covered with the resin part 120 can sufficiently protect the coil 110 mechanically and electrically, and the part where the coil 110 is exposed from the resin part 120 can efficiently radiate heat from that part. To. Here, each of the coil elements 110a and 110b is covered with a resin portion 120 on a part of the upper and lower surfaces, both end surfaces, and the inner peripheral surface, and each is held in a compressed state with substantially no gap between turns. Yes. In addition, both outer surfaces of the coil elements 110a and 110b are covered with the substrate 310 of the radiating fin 300, and the substrate 310 is embedded in the resin portion 120, so that the radiating fin 300 is integrated with the coil 110. And the protrusion 320 of the radiation fin 300 is exposed from the resin part 120, and the efficient heat dissipation from the protrusion 320 is achieved.

  The form of the resin portion 120 is molded into a structure that substantially follows the shape of the coil 110. That is, the thickness of the portion that covers the turn forming portions of both coil elements 110a and 110b in the resin portion 120 is substantially uniform, and the portion that covers the winding portion 110r has a shape protruding in the axial direction of the coil 110. is there.

  Of the resin portion 120, the constituent resin covering the inner periphery of each of the coil elements 110a and 110b forms a hollow hole 120h. A coil winding part 220 (FIG. 1) of the magnetic core 200 is inserted and arranged in each hollow hole 120h. At that time, the thickness of the resin part 120 that forms the hollow hole 120h is set so that each coil winding part 220 is coaxially arranged on the inner circumference of the coil elements 110a and 110b, and the hollow hole 120h The cross-sectional shape is matched to the outer shape of the coil winding portion 220 (here, a rectangular parallelepiped shape). Therefore, the resin part 120 forming the hollow hole 120h functions as a positioning part of the coil winding part 220 and further functions as an insulating member between the coil winding part 220 and the coil 110.

  Further, in this example, the upper surface of the resin portion 120 covering the coil 110 (the surface on the side from which the end of the winding 110w is drawn) is planar, and the bottom surface facing this upper surface is the surface of both coil elements 110a and 110b. The surface is uneven along the outer shape. More specifically, the resin portion 120 is provided with a dent in a portion covering a gap having a triangular cross section formed between the coil elements 110a and 110b. This dent has a trapezoidal cross section, and is provided in the entire region from one end surface of the coil molded body 100 to the other end surface along the axial direction of the coil 110 (FIG. 1). The shape of the dent, the formation region, the depth, and the like can be selected as appropriate. If the bottom surface is an uneven surface, the amount of the constituent resin of the resin portion 120 can be reduced, and the heat dissipation from the recessed portion can be enhanced. Moreover, if the protrusion corresponding to a dent is formed in the cooling base which is the installation object of a reactor, position alignment with respect to the cooling base of a reactor can be performed easily. Of course, you may shape | mold the resin part 120 in the form without a dent.

  The resin part 120 has a heat resistance that does not soften against the maximum temperature of the coil 110 and the magnetic core 200 when the reactor 1 including the coil molded body 100 is used. Transfer molding and injection molding Can be suitably used. In particular, a material having excellent insulating properties is preferable. Specifically, thermosetting resins such as epoxy, thermoplastic resins such as polyphenylene sulfide (PPS) resin and liquid crystal polymer (LCP) can be suitably used. Here, an epoxy resin is used. Further, as a constituent resin of the resin portion 120, heat dissipation can be improved by using a mixture of a filler made of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, and silicon carbide. .

(Molding of coil molded body)
The coil molded body 100 can be manufactured using a molding die as described below. As the molding die, one constituted by a pair of a first die and a second die that can be opened and closed in the axial direction of the coil 110 can be used. The first mold has a rectangular parallelepiped shape inserted into one end side of the coil 110 (the side from which the end of the winding 110w is drawn out in FIG. 1) and the inner circumference of each of the coil elements 110a and 110b. The second mold includes an end plate located on the other end side of the coil 110 (on the winding portion 110r side in FIG. 1), and a peripheral side wall that covers the periphery of the coil 110. The first mold and the second mold include a plurality of rod-shaped bodies that can be moved back and forth inside the mold by a drive mechanism, and these rod-shaped bodies allow the end surfaces of the coil elements 110a and 110b (turn forming portions to be annular). The coil elements 110a and 110b are compressed by appropriately pressing the visible surface. The rod-shaped body has sufficient strength against compression of the coil 110 and heat resistance against heat at the time of molding of the resin part 120, and in order to reduce the number of places not covered with the resin part 120 in the coil 110, It is preferable to make it as thin as possible.

  The coil 110 is arranged in the molding die so that a certain gap is formed between the surface of the molding die and the coil 110. At this time, the coil 110 is not yet compressed.

  Further, the radiation fins 300 are arranged so that the substrate 310 is opposed to each outer surface of the coil 110. A recess is formed in a portion of the inner surface of the peripheral side wall of the second mold that faces the protrusion 320 of the radiating fin 300, and the protrusion 320 of the radiating fin 300 is not damaged by the mold. Further, since the protrusion 320 of the radiating fin 300 extends along the axial direction of the coil 110, the protrusion 320 does not obstruct the opening and closing of the mold if a mold that opens and closes in the axial direction of the coil 110 is used. . If necessary, an appropriate jig that protrudes into the mold may be used in order to prevent the displacement of the radiating fin 300 in the mold.

  Next, the molding die is closed, and the core of the first die is inserted into the inner circumference of each of the coil elements 110a and 110b. At this time, the interval between the inner periphery of the core and the coil elements 110a and 110b is made to be substantially uniform over the entire periphery of the core.

  Subsequently, the rod-shaped body is advanced into the molding die to compress the coil elements 110a and 110b. By this compression, the gap between adjacent turns constituting each of the coil elements 110a and 110b is reduced.

  Thereafter, the resin is injected into the molding die from the resin injection port and solidified. By solidifying the resin, the coil 110 is held in a compressed predetermined shape, and the coil molded body 100 in which the coil 110 and the radiation fin 300 are integrated is molded. Thereafter, the molding die is opened, and the coil molded body 100 is taken out.

  Note that the plurality of small holes formed in the portion pressed by the rod-shaped body may be left as it is or may be filled with an appropriate insulating material or the like. Moreover, when forming a dent in the bottom face side of the resin part 120, what has a protrusion for forming a dent is utilized for a metal mold | die.

[Magnetic core]
The magnetic core 200 is a member for making the magnetic field generated by the excitation of the coil 110 an annular magnetic path. The magnetic core 200 includes a pair of rectangular coil winding portions 220 in which the coil elements 110a and 110b are disposed, and a pair of end cores 210 in which the coil elements 110a and 110b are not substantially disposed. A closed loop (annular) magnetic core 200 is formed by disposing the end core 210 so as to sandwich the coil winding portions 220 that are spaced apart and arranged in parallel.

  The coil winding section 220 is configured by alternately laminating core pieces 220m made of a soft magnetic material containing iron such as iron or steel and gap members 220g made of a nonmagnetic material such as alumina. Each core piece 220m may be a soft magnetic powder compact or a laminate in which a plurality of electromagnetic steel sheets are laminated. The gap member 220g is a member disposed in a gap provided between the core pieces 220m for adjusting the inductance (there may be an air gap). The core piece 220m and the gap material 220g are integrally joined with an adhesive or the like. The number of divisions of the core piece 220m and the number of gap members 220g can be selected as appropriate so that the coils 110 each have a desired inductance.

  The end core 210 is also made of a soft magnetic material similar to the core piece 220m of the coil winding portion 220. In this example, one surface (the lower surface in FIG. 1) of the end core 210 has a shape protruding downward from the coil winding portion 220. When the reactor is installed on the cooling base, the surface facing the cooling base is used as the installation surface of each component of the reactor. If the installation surface of the end core 210 is flush with the installation surface of the coil molded body 100, both installation surfaces can be brought into contact with the cooling base, and high heat dissipation characteristics can be expected.

[Reactor assembly procedure]
In order to assemble the reactor 1, first, a coil molded body 100 is prepared. Next, the coil piece 220 is formed by fixing the core piece 220m and the gap member 220g with an adhesive or the like. Subsequently, the coil winding part 220 is inserted and disposed in the hollow hole 120 h of the coil molded body 100. Since the hollow hole 120h is formed to have a predetermined thickness by the constituent resin of the resin part 120 of the coil molded body 100 as described above, each coil winding part 220 inserted into the hollow hole 120h is a coil. Arranged at appropriate positions with respect to the elements 110a and 110b (FIG. 2). Then, the end core 210 is disposed so that both end surfaces of the coil molded body 100 are sandwiched between the pair of end cores 210, and the end core 210 and the coil winding portion 220 are joined with an adhesive or the like.

[Effect]
Since the shape of the coil 110 is held by the resin portion 120, the coil 110 can be handled as a member that does not expand and contract. Furthermore, since the heat radiating fin 300 can also be handled as an integral part of the coil 110, the assembly workability of the reactor is further improved. Further, since the heat radiating fin 300 is integrally formed with the resin portion 120 together with the coil 110, the shape retention of the coil 110 and the fixing of the heat radiating fin 300 to the coil 110 can be performed simultaneously by one resin molding. And by providing the radiation fin 300, it can be set as the reactor excellent in the thermal radiation characteristic.

[Embodiment 2]
Next, the reactor according to the present invention in which the resin part has a two-layer structure of the inner resin part 120i and the outer resin part 120o will be described with reference to FIG. In FIG. 3, a part of the outer resin portion 120o is cut away so that the magnetic core 200 and the coil molded body 100 enclosed in the outer resin portion 120o can be seen. In this example, the inner resin portion 120 i corresponds to the resin portion 120 of the first embodiment, and the inner resin portion 120 i retains the coil 110. However, the inner resin portion 120i does not hold the heat radiation fin 300. The main difference between the present embodiment and the first embodiment is that the outer resin portion 120o holds the heat radiation fin 300, and other configurations are basically the same as those of the first embodiment.

(Inner resin part)
The coil molded body 100 used in this example has a configuration in which the heat radiating fin 300 is not held and the outer surface of the coil 110 is exposed from the inner resin portion 120i. In such a coil molded body 100, when the inner resin portion 120i is molded, the coil 110 may be disposed without arranging the radiating fins 300 in the molding die.

(Outside resin part)
The outer resin portion 120o covers the combined body 10 of the coil molded body 100 and the magnetic core 200, and holds the radiation fins 300. Here, the outer resin portion 120o is formed substantially along the outer shape of the combined body 10 by casting the epoxy resin after producing the combined body 10. And the board | substrate 310 of the radiation fin 300 is embed | buried under the outer side resin part 120o.

  However, the end portions of the winding 110w and the protrusions 320 of the radiating fins 300 are exposed from the outer resin portion 120o. Further, the installation surface of the end core 210 and the installation surface of the coil molded body 100 are configured to be flush with each other and exposed from the outer resin portion 120o. Therefore, when the reactor 1 is installed on the cooling base (not shown), the installation surface of the end core 210, the installation surface of the coil molded body 100, and the installation surface of the outer resin portion 120o are all in contact with the cooling base.

  Further, the outer resin portion 120o of the present example extends to a place where the combination 10 does not exist so that the outer shape on the installation surface side is a rectangular shape. Bolt holes 120b for bolts (not shown) for fixing the reactor 1 to the cooling base are provided at the four corners of the rectangular flange portion 120f. Each bolt hole 120b is formed of a reinforcing metal tube, but may be formed of resin itself. Examples of the metal tube include those made of brass, steel, stainless steel, and the like. The thickness of the flange portion 120f, the number of bolt holes 120b, and the like can be selected as appropriate.

  In the outer resin portion 120o, the portion excluding the flange portion 120f has a uniform average thickness of 1 to 2 mm, and the thickness of the outer resin portion 120o in the portion and the covering region for the combined body 10 can be appropriately selected. . For example, not only the installation surface of the end core 210 and the installation surface of the coil molded body 100 but also a part of the end core 210 and a part of the coil molded body 100 can be exposed from the outer resin portion 120o. .

  As the constituent resin of the outer resin portion 120o, for example, urethane resin, PPS resin, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin and the like can be used in addition to the epoxy resin. The constituent resin of the outer resin portion 120o may be the same as or different from the constituent resin of the inner resin portion 120i of the coil molded body 100. Further, if the constituent resin of the outer resin portion 120o also contains the above-described filler made of ceramics, heat dissipation can be improved.

[Reactor assembly procedure]
The coil assembly 100 and the magnetic core 200 are combined to form the combined body 10. The obtained combined body 10 and the radiating fin 300 are arranged in a mold, and the installation surface of the end core 210, the installation surface of the coil molded body 100, the end of the winding 110w, and the protrusion 320 of the radiating fin 300 are provided. The outer resin part 120o is molded so as to be exposed. In addition, the flange portion 120f is molded on the installation surface side of the outer resin portion 120o, and the metal tube is disposed at a predetermined position to simultaneously mold the bolt hole 120b. Instead of insert molding the metal tube, a through hole may be formed with resin, and a metal tube may be inserted into the through hole to form the bolt hole 120b. The obtained reactor 1 is placed on the cooling base. Then, the reactor 1 can be fixed to the cooling base by passing the bolt through the bolt hole 120b of the flange portion 120f and further tightening the bolt into the bolt hole of the cooling base. By appropriately providing heat radiation grease, a heat radiation sheet, or the like between the installation surface of the reactor 1 and the cooling base, the thermal resistance between the reactor 1 and the cooling base can be reduced.

[Function and effect]
Even in the configuration of this example, since the coil molded body 100 is used, the coil 110 can be handled as a member that does not expand and contract. Moreover, by covering the coil molded body 100 and the magnetic core 200 together with the outer resin portion 120o, not only the coil 110 but also the magnetic core 200 can be sufficiently protected mechanically and electrically. Further, by holding the heat radiating fins 300 by the outer resin part 120o, it is possible to fix the heat radiating fins 300 to the assembly 10 collectively when the outer resin part 120o is molded.

  In addition, it is good also as a structure which covers the reactor of Embodiment 1 with the outer side resin part 120o. In that case, high heat dissipation characteristics can be obtained by exposing the installation surface of the reactor of Embodiment 1 and the protrusions 320 of the heat radiation fin 300 from the outer resin portion 120o.

[Embodiment 3]
Next, there is no inner resin part that holds the coil before combining with the magnetic core, but the configuration in which the heat radiation fin is held by a single resin part corresponding to the outer resin part 120o of the second embodiment is based on FIG. I will explain.

  In this example, the same coil 110 and magnetic core 200 as in the first embodiment are combined. If necessary, a bobbin (not shown) made of an insulating material may be interposed between the coil 110 and the magnetic core 200. At this stage, the coil 110 is not covered with any resin portion. The combined body 10 of the coil 110 and the magnetic core 200 is disposed in the mold 400. Further, the heat radiating fins 300 are also arranged in the mold 400. The shape and material of the radiating fin 300 are the same as those in the first embodiment, and the arrangement location is also on the outer surface side of the coil 110. A recess for avoiding the ridge 320 is formed at a location facing the ridge 320 of the radiating fin 300 in the mold 400. With this recess, the protrusion 320 of the radiating fin 300 is prevented from being covered with the resin portion 120. The mold 400 here is a mold that opens and closes in the parallel direction of the coil elements 110a and 110b (the left-right direction in FIG. 4). A resin part 120 is molded by filling the mold 400 with resin. When molding is completed, the molded body is removed from the mold 400.

  By the above molding, a reactor in which the resin portion 120 is integrated with the coil 110, the magnetic core 200, and the heat radiation fin 300 is obtained. That is, the coil 110 and the magnetic core 200 can be fixed and the heat radiation fin 300 and the coil 110 can be fixed by molding once. Further, since not only the coil 110 but also the outer periphery of the magnetic core 200 is covered with the resin portion 120, both the coil 110 and the magnetic core 200 can be sufficiently protected mechanically and electrically. Of course, in this example, the installation surface of the end core and the installation surface of the coil 110 may be exposed from the resin portion 120.

[Embodiment 4]
Next, the reactor of the present invention in which the heat dissipating fin is constituted by a part of the resin portion will be described. When the resin part is molded in the first and third embodiments or the outer resin part is molded in the second embodiment, the reactor forms the heat radiating fin by molding without using a separately prepared heat radiating fin. That is, an uneven surface corresponding to the protrusion of the heat radiation fin may be formed at a location corresponding to the heat radiation fin of the molding die.

  In particular, it is preferable to use a resin in which a highly thermally conductive filler is dispersed in the entire resin portion or at least a portion that becomes a radiation fin. Thereby, the heat dissipation characteristic of a radiation fin can be improved.

  According to this example, the resin part for retaining the shape of the coil, the resin part for integrating the coil and the magnetic core, and the heat radiation fin can be formed.

[Embodiment 5]
In the above first to fourth embodiments, the radiating fins are fixed to the side surface of the coil, but instead or additionally, the radiating fins may be fixed to the core. For example, fixing the radiating fin to the end surface (both end surfaces in the coil axis direction of FIG. 1) or the upper surface of the end core can be mentioned. The fixing of the heat radiating fins to the core may be, for example, integrally molded by the outer resin portion in the second embodiment or the resin portion in the third embodiment.

  If a heat radiating fin is provided in the core, the heat generated in the core can also be efficiently radiated through the heat radiating fin. Along with this, it is possible to construct a reactor with further excellent heat dissipation characteristics.

[Modification]
The present invention is not limited to the above embodiment, and various changes can be expected. For example, in Embodiment 1, although the structure which has a hollow hole as a coil molded object was shown, it is good also as a structure by which the coil winding part of the magnetic core was integrated with this hollow hole by the resin part. In that case, what is necessary is just to arrange | position a coil winding part to the inner periphery of a coil element instead of a core when shape | molding a resin part. According to this structure, the coil, the radiation fin, and the coil winding part of the magnetic core can be handled as a single member integrated with the resin part.

  The reactor of this invention can be utilized as components, such as a converter. In particular, it can be suitably used as a reactor for automobiles such as hybrid cars and electric cars.

1 Reactor
10 Union
100 coil molded body
110 coils
110a, 110b Coil element 110r Winding part 110w Winding
120 resin part
120i Inner resin part
120h hollow hole
120o Outer resin part
120f Flange part 120b Bolt hole
200 magnetic core
210 end core
220 Coil winding part
220m core piece 220g gap material
300 Heat dissipation fin
310 Substrate 320 Projection
400 mold

Claims (7)

A reactor comprising an annular magnetic core having a pair of coil winding portions, and a pair of coil elements disposed on the outer periphery of both coil winding portions,
Radiating fins,
A reactor comprising: a resin portion that integrally molds at least one of the core and the coil element and a radiation fin.   The reactor according to claim 1, wherein the radiating fin is provided on a side surface of each coil element.   The reactor according to claim 1, wherein the radiating fin is configured by a part of the resin portion.   The reactor according to claim 1, wherein the radiating fin is made of a nonmetallic material.   The reactor according to claim 1, wherein the radiating fin is made of a metal material. The resin part is
An inner resin portion that retains the shape of the coil element;
An outer resin part formed on the outer side of the inner resin part,
The reactor according to claim 1, wherein the radiating fin is molded integrally with an inner resin portion. The resin part is
An inner resin portion that retains the shape of the coil element;
An outer resin part formed on the outer side of the inner resin part,
The reactor according to any one of claims 1 to 5, wherein the radiating fin is formed integrally with an outer resin portion.

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