JP2010165951A - Reactor and molded coil body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact reactor excellent in heat radiation, and also a molded coil body suitable as a constituent component in the reactor. <P>SOLUTION: A molded coil body 1 includes coil 3 obtained by spirally winding a wire 3w, a molded resin 4c covering an outer periphery of the coil 3, and a heat radiating plate 5 located at the outer periphery of the coil 3 and fixed by the molded resin 4c. The heat radiating plate 5, which is rectangular, includes a buried surface 51 not exposed in the molded resin 4c, an exposed surface 52 opposed to the buried surface 51 and exposed from the molded resin 4c, and four end faces. Two end faces 5e are formed in a trapezoidal shape becoming narrow from the buried surface 51 toward the exposed surface 52. The remaining two end faces includes a tilted rectangular surface 53. A triangular part formed by the buried surface 51 and the tilted surface 53 functions as an engagement for preventing falling off of the heat radiating plate 5. The reactor including the molded coil body 1 is excellent in heat radiation due to provision of the heat radiating plate 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a reactor used for a component of an in-vehicle DC-DC converter such as a hybrid vehicle, and a coil molded body used for a component of the reactor. In particular, the present invention relates to a small reactor having excellent heat dissipation.

  Conventionally, a reactor in which a coil is arranged on the outer periphery of a magnetic core is known. A typical structure is a structure (Patent Document 1) in which a combination of a magnetic core and a coil is housed in a metal case such as aluminum and the inside of the case is sealed with resin. This reactor is used by fixing the case to a frame containing a refrigerant so that the coil and the magnetic core that generate heat when energized can be efficiently cooled.

Japanese Patent Laid-Open No. 2008-098204

  In-vehicle components arranged in vehicles such as automobiles are desired to be small and lightweight. However, it is difficult to reduce the size and weight of a conventional reactor by providing a case. It is conceivable to omit the case, but in that case, there is a concern about a decrease in heat dissipation.

  Then, one of the objectives of this invention is providing the reactor which is excellent in heat dissipation, although it is small. Moreover, the other objective of this invention is to provide the coil molded object suitable for the component of the said reactor.

  The inventors have studied a configuration in which the case is omitted and a heat radiating plate is disposed on the gantry side on the outer periphery of the coil. Moreover, the structure which fixes the outer periphery of a coil and the outer periphery of the combination of a magnetic core and a coil with resin, and fixes a heat sink to the outer periphery of a coil with this resin was examined. The shape of the heat radiating plate is a general rectangular plate, that is, a shape composed of two rectangular surfaces facing each other and four rectangular end surfaces that are connected between the two surfaces and orthogonal to the two surfaces. When manufacturing a reactor with a heat sink placed under the coil, when the reactor is lifted and moved, the end face of the heat sink becomes parallel to the drop direction, causing the heat sink to fall off and fall. The In order to prevent the heat sink from falling, if the heat sink is fixed by using a fixing member such as a bolt separately, the number of parts and work processes are increased. Therefore, the present invention suppresses the falling of the heat radiating plate by making it difficult to come off the heat radiating plate so that the effect of improving the heat radiating property due to the presence of the heat radiating plate can be sufficiently obtained.

  The coil molded body of the present invention is a member used for a reactor in which a coil formed by spirally winding a coil is disposed on the outer periphery of a magnetic core, and the coil is held in a compressed state rather than its free length. A resin molded part that is disposed on the outer periphery of the coil, and a heat-dissipating plate that will be described later fixed by a resin component of the resin molded part. The reactor of the present invention includes this coil molded body and a magnetic core disposed on the inner periphery of the coil.

  A reactor that does not include a coil molded body is proposed separately from the reactor that includes the coil molded body. The reactor according to the present invention includes a magnetic core, a coil disposed on the outer periphery of the core, a resin coating that covers the outer periphery of the combination of the magnetic core and the coil, and an outer periphery of the coil. The following heat radiating plate fixed by the constituent resin of the resin coating portion is provided.

  The heat dissipation plate provided in the above-described coil molded body of the present invention and the reactor of the present invention includes an embedded surface and an exposed surface. The embedded surface is a surface that is disposed on the coil side and is not exposed from the resin molded portion or the resin coating portion, and the exposed surface is opposed to the embedded surface and from the resin molded portion or the resin coating portion. The exposed surface. Further, in the heat radiating plate, an end surface region between the embedded surface and the exposed surface has a latching portion that prevents the heat radiating plate from falling off by being caught by the resin forming portion or the resin constituting the resin coating portion.

  According to the said structure, a heat sink is fixed to a resin molding part or a resin coating part in the state which the latching part provided in the end surface area | region of the heat sink was hooked by the resin of the resin molding part or the resin coating part. Therefore, even if the coil molded body of the present invention or the reactor of the present invention is lifted or moved so that the exposed surface of the heat radiating plate becomes downward during assembly or transportation of the reactor, the above-mentioned latching portion is not attached to the resin. By being caught, it can prevent effectively that a heat sink falls. Since the reactor of the present invention is excellent in heat dissipation due to the presence of this heat sink, for example, it is possible to adopt a configuration in which a metal case is omitted, and the size can be reduced, and the number of parts and work processes can be reduced. it can.

  In addition, when the reactor is assembled using the coil molded body of the present invention having the heat radiating plate, since the coil does not expand and contract during assembly, the coil is easy to handle and the reactor is easy to assemble.

  In the present invention, the shape of the latching portion of the heat sink is not particularly limited. For example, at least a part of the end region is a tapered surface that tapers from the embedded surface toward the exposed surface, and has a shape having an inclined surface that is not orthogonal to the embedded surface (exposed surface). . At this time, a triangular portion formed by the embedded surface and the inclined surface can be caused to function as a latching portion. When the constituent resin of the resin molded portion or the resin coating portion enters (exists) the triangular portion formed by the inclined surface and the extended surface of the exposed surface, the hook portion is caught by the resin. Alternatively, at least a part of the end region may have a latching portion by forming a step having a plate width that narrows from the embedded surface toward the exposed surface, that is, a shape having an inverted pyramid-shaped step. it can. The structure having the inclined surface is easier to mold the heat sink than the structure having the step, and is excellent in manufacturability of the heat sink. In the configuration having the step, the constituent resin of the resin molded portion or the resin coating portion easily reaches the corner of the step portion, and a gap is hardly generated between the heat sink and the resin molded portion or the resin coating portion. Moreover, when there are few inclined surfaces, it is excellent in the moldability of a heat sink, and when many, the fall prevention effect can be improved.

  More specifically, the heat radiating plate is a rectangular plate, and among the end surfaces of the rectangular plate, two opposing end surfaces are tapered surfaces that taper from the embedded surface toward the exposed surface, and the remaining two end surfaces are The thing which is an inclined surface inclined with respect to the embedding surface is mentioned. An example of the tapered surface is a trapezoidal shape. Since the heat radiating plate is a rectangular plate and only two end surfaces are inclined surfaces, the heat radiating plate is excellent in manufacturability and can effectively prevent the heat radiating plate from falling off.

  The constituent material of the heat sink is preferably a material having a thermal conductivity α (W / m · K) of more than 3 W / m · K, particularly 20 W / m · K or more, and more preferably 30 W / m · K or more. Since this heat radiating plate is disposed in contact with or close to the coil, it is preferable that the whole is made of a nonmagnetic material in consideration of magnetic characteristics. The material satisfying such characteristics is preferably a nonmagnetic inorganic material. Nonmagnetic inorganic materials include conductive materials and insulating materials. The constituent material of the embedded surface disposed on the coil side in the heat radiating plate is desirably electrically insulated from the coil, and is preferably an insulating material. Therefore, the heat dissipation plate may be composed entirely of an insulating inorganic material, or may have a laminated structure including a layer made of an insulating inorganic material on the surface of a plate-like substrate made of a conductive inorganic material. It may be a thing. Note that “insulating” has an insulating property that can ensure electrical insulation with the coil. Ceramics can be preferably used as the insulating inorganic material, and metals such as aluminum can be preferably used as the conductive inorganic material. A heat sink using ceramics is lightweight, and a heat sink using a metal material has high heat dissipation. In the case of using ceramics, a heat sink having a specific shape can be obtained by molding using a mold having a predetermined shape or by appropriately cutting the material plate by grinding or laser processing. When using a metal material, a heat sink with a specific shape can be obtained by appropriately cutting the material plate or forming it using a predetermined mold. Alternatively, a heat sink having a predetermined shape can be obtained by preparing a plurality of materials and bonding them with an adhesive or the like.

  This invention reactor can be set as the structure which does not have metal cases in the outer periphery. By omitting the case, this reactor has a small number of parts and is small and lightweight.

  In the reactor including the coil molded body of the present invention, the outer periphery of the combined body of the coil molded body and the magnetic core can be configured not to be covered with resin. Since this reactor does not require a step of coating the outer periphery of the assembly with a resin, it is excellent in assembling workability.

  The reactor of the present invention is excellent in heat dissipation while being small. By using the coil molded body of the present invention, a small reactor having excellent heat dissipation can be easily manufactured.

(A) is a schematic perspective view of the coil molded body of Embodiment 1, and (B) is a front view of the coil molded body. FIG. 3 is an exploded perspective view for explaining a manufacturing procedure of a reactor including the coil molded body according to the first embodiment. (A) is a front view of a coil molded body having a heat sink having a step in the end surface region, (B) to (D) are partial cross-sectional views showing an enlarged heat sink portion in the coil molded body, (B) is a heat radiating plate having a curved surface in the end surface region, (C) is a heat radiating plate having a protrusion in the end surface region, and (D) is a heat radiating plate having a parallelogram-shaped end surface. 5 is a schematic perspective view of a reactor according to Embodiment 2. FIG. 6 is a front view of a reactor according to Embodiment 2. FIG. It is a front view of the reactor of the modification 2-1.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 (A) is a perspective view showing an outline of the coil molded body of the present invention, FIG. 1 (B) is a front view of the coil molded body, and FIG. 2 is an exploded perspective view of a reactor including the coil molded body. It is. In the drawings, the same reference numerals denote the same items. The coil molded body 1 includes a coil 3 formed by winding a winding 3w in a spiral shape, a resin molded portion 4c that covers the outer periphery of the coil 3, and a resin that forms the resin molded portion 4c. And a heat sink 5 fixed by the The reactor 10 includes a coil molded body 1 and a magnetic core 2 (coil winding portion 2c) that is inserted and arranged on the inner periphery of the coil 3 of the coil molded body 1. The most characteristic feature of the coil molded body 1 and the reactor 10 is the shape of the end face of the heat sink 5. Hereinafter, each configuration will be described in more detail.

<Coil molding>
[coil]
The coil 3 includes a pair of coil elements that are formed by spirally winding one continuous winding 3w and arranged in parallel. The winding 3w 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 are formed by edgewise winding the covered rectangular wire, and are connected by a winding portion 3r. The windings can be used in various shapes such as a circular shape and a polygonal shape in addition to the conductor made of a flat wire. Alternatively, each coil element may be manufactured separately, and the ends of the windings forming each coil element may be joined by welding or the like to form an integral coil.

  Both end portions of the winding 3w forming the coil 3 are appropriately extended from the turn forming portion and drawn to the outside of the resin molding portion 4c, and the conductive material is exposed to the conductor portion exposed by peeling off the insulating coating layer. A terminal member (not shown) made of is connected. An external device (not shown) such as a power source for supplying power is connected to the coil 3 through this terminal member. For connection between the conductor portion of the winding 3w and the terminal member, welding such as TIG welding can be used.

[Resin molding part]
A resin molded portion 4c is formed on the outer periphery of the coil 3 so as to hold each coil element in a compressed state. Here, the resin molded portion 4c covers the entire coil 3 along the shape of the coil 3 except for both ends of the winding 3w. The thickness of the portion covering the turn forming portions of both coil elements in the resin molded portion 4c is substantially uniform, and the portion covering the winding portion 3r has a shape protruding in the axial direction of the coil.

  The inner periphery of each coil element is also covered with the constituent resin of the resin molded portion 4c, and has a hollow hole 4h formed of the constituent resin. A coil winding portion 2c (FIG. 2) of the magnetic core 2 (FIG. 2) is inserted and disposed in each hollow hole 4h. The thickness of the constituent resin is adjusted so that each coil winding portion 2c is arranged at an appropriate position on the inner periphery of the coil element, and the shape of the hollow hole 4h is changed to the outer shape of the coil winding portion 2c (here, a rectangular parallelepiped shape). ). Therefore, the constituent resin present on the inner periphery of each coil element functions as a positioning portion for the coil winding portion 2c.

  In the example shown in FIG. 1, the entire inner circumference of each coil element is covered with the constituent resin. However, the insulation distance between the magnetic core 2 and the coil 3 can be secured, and positioning can be performed as described above. If the constituent resin is present, the entire inner circumference of each coil element may not be covered with the constituent resin as in the example shown in FIG.

  The resin component of the resin molded part 4c is a material that has heat resistance that does not soften against the maximum temperature of the coil or core when the coil molded body 1 is used as a reactor, and that can be transfer molded or injection molded. 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.

[Heatsink]
The coil molded body 1 is arranged so that both coil elements are arranged side by side and attached to a gantry (not shown). In each coil element, the heat radiating plate 5 is arranged so as to be in contact with the surface (coil element installation surface) attached to the gantry. The heat radiating plate 5 is fixed to the coil 3 with the constituent resin of the resin molded portion 4c.

  The heat radiating plate 5 is a rectangular plate and is disposed so as to be in contact with the installation surfaces of both coil elements. More specifically, the heat radiating plate 5 includes an embedded surface 51 that is not exposed from the resin molded portion 4c, an exposed surface 52 that faces the embedded surface 51 and is exposed from the resin molded portion 4c, and the embedded surface 51 is exposed. It is composed of four end faces that connect the face 52. Here, the embedding surface 51 is assumed to have a size capable of sufficiently contacting with the installation surfaces of both coil elements. It is good also as a structure which has arrange | positioned so that it may be in contact with the installation surface of each coil element by using two heat sinks.

  Of the four end surfaces of the heat sink 5, the two opposite end surfaces 5e are tapered, more specifically, trapezoidal that tapers from the embedded surface 51 toward the exposed surface 52 as shown in FIG. Therefore, the embedded surface 51 is larger than the exposed surface 52. The trapezoidal end surface 5e is orthogonal to the embedded surface 51 and the exposed surface 52. On the other hand, the remaining two end surfaces are rectangular and are inclined surfaces 53 that are non-orthogonal to the embedded surface 51 and the exposed surface 52 and intersect the thickness direction of the heat sink 5. Here, the heat radiating plate 5 is arranged so that the trapezoidal end face 5 e faces the axial direction of the coil 3.

Radiating plate 5 of the specific shape, silicon nitride (Si ₃ N _4): it is composed of about 20~150W / m · K. Here, the heat sink 5 is formed by molding the constituent material (Si ₃ N ₄ ) into a predetermined shape.

  In the heat sink 5, a triangular portion formed by the embedded surface 51 and the inclined surface 53 functions as a latching portion that prevents the heat sink 5 from falling off. Further, by means of a triangular portion (receiving portion 4n) constituted by the resin of the resin molded portion 4c that has entered the triangular space formed by the extended surface of the exposed surface 52 and the inclined surface 53, the heat sink 5 is It is firmly fixed to the resin molded part 4c. When the coil molded body 1 is lifted or moved upward in a state where the coil molded body 1 is arranged so that the exposed surface 52 is downward as shown in FIG. Even if it is about to fall, the above-mentioned latching part is caught by the receiving part 4n, and the heat sink 5 is difficult to fall. In this example, the corners of the heat radiating plate 5 have a sharp shape, but if the corners are rounded, cracks at the corners of the heat radiating plate 5 can be prevented.

[Manufacture of coil compacts]
The coil molded body 1 including the heat radiating plate 5 can be manufactured by using a molding die as described below. As the molding die, one constituted by a pair of first and second molds that can be opened and closed can be used. The first mold comprises an end plate located on one end side of the coil 3 (the side from which the end of the winding 3w is pulled out in FIG. 1), and a core inserted into the inner periphery of each coil element, The second mold includes an end plate located on the other end side of the coil (on the winding portion 3r side in FIG. 1) and a peripheral side wall covering the periphery of the coil 3. Further, the first and second molds include a plurality of rod-like bodies that can be advanced and retracted inside the mold by a drive mechanism, and these rod-like bodies allow end faces of the coil elements (surfaces in which the turn forming portions look annular). Is suitably pressed to compress the coil element. The rod-shaped body has sufficient strength against compression of the coil 3 and heat resistance against heat during molding of the resin molded portion 4c, and reduces the number of portions of the coil 3 that are not covered with the resin molded portion 4c. In addition, it is as thin as possible.

  The coil 3 is arranged in the molding die so that a certain gap is formed between the surface of the molding die and the coil 3. Further, the heat sink 5 is disposed at a predetermined position between the inner periphery of the molding die and the outer periphery of the coil 3. At this time, the coil 3 is not yet compressed.

  Next, the molding die is closed, and the core of the first die is inserted into the inner periphery of each coil element. At this time, the interval between the inner periphery of the core and the coil element is made substantially uniform over the entire periphery of the core.

  Subsequently, the rod-shaped body is advanced into the molding die to compress each coil element. By this compression, adjacent turns constituting each coil element are brought into contact with each other, and there is no gap between the turns. In addition, the embedded surface of the heat sink 5 is placed in contact with the compressed coil 3.

  Then, after injecting resin into the molding die from the resin injection port and solidifying, the molding die is opened, the coil 3 is held in a compressed state, and the heat sink 5 is fixed to the outer periphery of the coil 3 The molded body 1 is taken out. Note that the plurality of small holes formed in the portion pressed by the rod-shaped body may be filled with an appropriate insulating material or the like, or may be left as it is.

  In the above manufacturing method, the method of fixing the heat sink at the same time as the formation of the resin molded portion of the coil molded body has been described, but a fitting groove into which the heat sink is fitted into the resin molded portion of the coil molded body is formed. Alternatively, the heat sink may be inserted into the fitting groove. The fitting groove is provided, for example, so as to pass through from one end side to the other end side in the axial direction of the coil and open at both ends so that the heat sink can be inserted. As such a coil molded body, it is preferable to use one having a core for further forming a fitting groove in the molding die. In this configuration, for example, the installation surface of the coil element is covered with a resin, and the constituent resin of the resin molded portion is present between the installation surface of the coil element and the heat radiating plate, so that the insulation can be improved. . This configuration can be applied to a later-described modified example or Embodiment 2 as long as the heat sink can be inserted.

<Reactor>
[Magnetic core]
As shown in FIG. 2, the magnetic core 2 has a pair of rectangular parallelepiped coil winding portions 2c in which the respective coil elements are respectively disposed, and a pair of end cores 2e in which the coils 3 are not disposed, and are separated from each other. The end core 2e is disposed so as to sandwich the coil winding portion 2c to be disposed, and is formed in a closed loop shape (annular shape). The coil winding portion 2c is configured by alternately laminating core pieces 2m made of a soft magnetic material containing iron such as iron or steel and gap members 2g made of a nonmagnetic material such as alumina, and an end core 2e is a core piece made of the soft magnetic material. Each core piece can be a soft magnetic powder compact or a laminate of a plurality of electromagnetic steel plates. The gap material 2g is a member disposed in a gap provided between the core pieces 2m for adjusting the inductance. The core piece and the gap material are integrally joined with an adhesive or the like. The number of core pieces divided and the number of gap members can be appropriately selected so that the reactor 10 has a desired inductance.

[Manufacture of reactors]
Reactor 10 is formed by inserting magnetic core 2 (coil winding part 2c) into hollow hole 4h of coil molded body 1 and assembling magnetic core 2. More specifically, the coil piece 2c is formed by fixing the core piece 2m and the gap material 2g with an adhesive or the like, and this coil winding part 2c is inserted and disposed in the hollow hole 4h. At this time, each coil winding portion 2c is inserted into a hollow hole 4h formed in a predetermined thickness by a resin component of the resin molded portion 4c of the coil molded body 1 so that each coil element is appropriate. It is arranged in the position. Next, the end core 2e is arranged so that both end faces of the coil element of the coil molded body 1 are sandwiched between the pair of end cores 2e, and the end core 2e and the coil winding portion 2c are bonded with an adhesive or the like. By joining, the reactor 10 is obtained.

  Although the reactor 10 may be left as it is, a resin portion may be further provided so as to cover the outer periphery of the combined body of the coil molded body 1 and the magnetic core 2. By providing this resin part, the combined body can be handled as an integrated object, and the handleability is excellent, and the magnetic core can be mechanically protected and protected from the environment. When the resin portion is provided, if the exposed surface 52 of the heat sink 5 is exposed from the resin portion, the heat sink 5 can be brought into direct contact with the gantry, so that the heat dissipation efficiency is good. As this resin portion, for example, epoxy resin, urethane resin, PPS resin, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin, or the like can be used. These resins can also be used for the constituent resin of the resin coating portion of Embodiment 2 described later.

<Effect>
The reactor 10 including the coil molded body 1 includes the heat radiating plate 5 and thus has excellent heat dissipation even when the case made of a metal such as aluminum is omitted. In particular, the coil molded body 1 has a configuration in which the heat radiating plate 5 is provided with a latching portion, and this latching portion is hooked on the constituent resin (receiving portion 4n) of the resin molded portion 4c. Therefore, when the coil molded body 1 is transported, when the coil molded body 1 is lifted or moved when the reactor 10 is assembled, and when the reactor 10 including the coil molded body 1 is transported or attached to the gantry, etc. Even when lifted or moved, the heat sink 5 is difficult to drop. Therefore, it is expected that the reactor 10 can fully utilize the excellent heat dissipation due to the presence of the heat sink 5. Further, since the heat radiating plate 5 is disposed in contact with the installation surface on the side where the coil 3 is installed on the gantry, the heat of the coil 3 can be efficiently transmitted to the gantry.

  Furthermore, the coil molded body 1 has a structure in which the heat radiating plate 5 is fixed to the outer periphery of the coil 3 by the constituent resin of the resin molded portion 4c, and the heat radiating plate 5 is firmly fixed by having a latching portion. Therefore, a fixing member such as a bolt for fixing the heat radiating plate is unnecessary, and the number of parts and work processes can be reduced. In particular, since the fixing operation of the heat sink 5 is performed simultaneously with the formation of the resin molding portion 4c as described above, even the heat sink 5 having a complicated shape is easily integrated with the coil molded body 1. be able to.

  Furthermore, the coil molded body 1 also covers the inner periphery of each coil element with the constituent resin of the resin molded portion 4c, and by making the constituent resin into a predetermined thickness and shape, the magnetic core 2 (coil winding portion 2c) It can be used for positioning. Therefore, the coil molded body 1 can easily position the magnetic core 2 without using a positioning member such as a bobbin, and can reduce the number of parts and work processes. In addition, since the constituent resin of the resin molding portion 4c is an insulating resin, the magnetic core 2 and the coil 3 can be insulated by the constituent resin that covers the inner periphery of the coil element. An insulating member is unnecessary, and the number of parts and work processes can be reduced. In addition, the heat sink 5 shown in this example is easy to manufacture because all of the four end surfaces are flat surfaces and only the two end surfaces 53 are inclined surfaces. By using the coil molded body 1 in this manner, the reactor 10 having a small number of parts and a small size and excellent heat dissipation can be obtained. Further, since the reactor 10 does not separately cover the outer periphery of the combined body of the coil molded body 1 and the magnetic core 2 with a resin, this resin coating step is unnecessary, and the assembly workability is excellent.

(Modification 1-1)
In the first embodiment, the heat radiating plate is described which is made of a rectangular plate, the two end surfaces are trapezoidal, and the trapezoidal end surfaces are orthogonal to the embedded surface and the exposed surface. You may deform | transform a heat sink as follows. The following configurations (1) and (2) can also be applied to each modified example and Embodiment 2 described later.
(1) The four end surfaces are trapezoidal, and all end surfaces are inclined with respect to the buried surface and the exposed surface. This heat sink has a triangular portion formed by the embedded surface and the four tapered end faces, i.e., the number of hooks increases. Dropout can be prevented more effectively.
(2) The buried surface and exposed surface shall be polygonal. This heat radiating plate has many end surfaces, and these end surfaces are inclined to increase the number of latching portions, thereby making it easier to catch on the constituent resin of the resin molded portion and more effectively preventing the heat radiating plate from falling off. be able to.

(Modification 1-2)
FIG. 3 shows a coil molded body having a heat radiating plate having a shape different from that of Embodiment 1, (A) is a front view of the coil molded body having a heat radiating plate having a step in the end surface region, and (B). (D) is a partial cross-sectional view showing an enlarged heat dissipation plate part in the coil molded body, (B) is a heat dissipation plate having a curved surface in the end surface region, and (C) is a heat dissipation having a protrusion in the end surface region. A plate, (D), shows a heat radiating plate having a parallelogram-shaped end surface. The configuration of the modified example 1-2 can also be applied to modified examples described later and the second embodiment.

  (A) In Embodiment 1 above, when the two opposite end surfaces 5e are tapered from the embedded surface toward the exposed surface, the heat sink is a tapered shape, i.e., a virtual plane parallel to the embedded surface is taken. A heat sink having a shape in which the virtual surface continuously decreases toward the exposed surface has been described. Like the heat radiating plate 5A shown in FIG. 3 (A), when the two opposing end surfaces take the above virtual surface, the virtual surface is gradually reduced from the embedded surface 51A toward the exposed surface 52A. Also good. The heat radiating plate 5A shown in this example is a rectangular plate, and two end face regions facing each other have a single stepped shape as shown in FIG. 3 (A). That is, when the heat sink 5A takes the virtual surface, a virtual surface having the same area as the embedded surface 51A can be taken from the embedded surface 51A to a predetermined range in the thickness direction, and from the predetermined position to the exposed surface 52A. Is a shape in which a virtual surface having the same area as the exposed surface 52A is taken, and the embedded surface 51A side protrudes from the exposed surface 52A side. The protruding embedded surface 51A side region functions as a latching portion, and is hooked by the rectangular receiving portion 4An configured by the resin of the resin molded portion 4c that has entered the recessed rectangular space on the exposed surface 52A side. Thus, the heat sink 5A is unlikely to drop as in the first embodiment. If all the end surface regions have such a step shape, the effect of preventing the fall can be enhanced. Further, in the heat sink 5A, the constituent resin of the resin molded portion 4c is likely to spread to every corner of the recessed rectangular space on the exposed surface 52A side, and the heat sink 5A is easily fixed firmly by the constituent resin.

  (B) In the first embodiment, the heat radiating plate in which the inclined surface 53 is a flat surface has been described. The inclined surface 53B may be a curved surface as in the heat radiating plate 5B shown in FIG. In this heat sink 5B, the curved portion formed by the embedded surface 51B and the inclined surface 53B functions as a latching portion, and the resin molded portion 4c is firmly attached to the resin molded portion 4c by the receiving portion 4Bn configured by the resin constituting the resin molded portion 4c. It is fixed to and difficult to fall. Note that all the end surface regions may have such a curved surface shape, or a combination of a curved surface and a flat surface.

  (C) As described in (A) above, when the heat sink of Embodiment 1 takes a virtual surface parallel to the embedded surface, the virtual surface continuously decreases from the embedded surface toward the exposed surface. This is the shape. Like the heat sink 5C shown in FIG. 3 (C), when taking the virtual surface, a shape that can take a virtual surface having a larger area than the exposed surface 52C between the embedded surface 51C and the exposed surface 52C, that is, A shape having a protrusion 54 between the embedded surface 51C and the exposed surface 52C may be used. The protrusion 54 has a rectangular parallelepiped shape and functions as a hooking portion. The heat radiating plate 5C is firmly fixed to the resin molded portion 4c by the hook portion (protrusion 54) being hooked on the receiving portion 4Cn of the shape formed of the constituent resin of the resin molded body 4c, and hardly falls. If the protrusions 54 are present not only in the two opposing end face areas but also in all the end face areas, the effect of preventing the heat sink from falling can be enhanced. In the heat sink 5C shown in this example, the embedded surface 51C and the exposed surface 52C have the same area, but the exposed surface may be smaller than the embedded surface as in the heat sink 5 of the first embodiment. Further, the shape of the protrusion 54 is not particularly limited. Such a heat sink 5C can be manufactured by molding, but can be easily formed by joining a plurality of thin plates.

(D) The radiator plate of Embodiment 1 has a shape in which the exposed surface is smaller than the embedded surface. Like the heat sink 5D shown in FIG. 3D, the embedded surface 51D and the exposed surface 52D may have the same area. At this time, of the four end surfaces of the heat sink 5D, the two opposing end surfaces 5De are in a parallelogram shape, and the remaining two opposing end surfaces are the inclined surfaces 53D. Similarly to the heat sink 5 of the first embodiment, this heat sink 5D also functions as a hook portion formed by the embedded surface 51D and one inclined surface 53D, and is made of a resin component of the resin molded portion 4c. By being hooked on the triangular receiving portion 4Dn, it is firmly fixed to the resin component 4c and hardly falls. In particular, by adjusting the manner magnitude caught enough to triangular engaging portion receiving portions 4D _n, can be more difficult to drop. In addition, since the heat sink 5D has an embedded surface 51D and an exposed surface 52D of the same area, heat from the coil can be efficiently transferred to the gantry, so the reactor including the heat sink 5D Excellent. In order to sufficiently enhance the effect of preventing the fall, it is preferable to have a plurality of latching portions as in the first embodiment.

  In addition, the shape of the embedded surface and the exposed surface may be a shape other than a rectangular shape or a polygonal shape, for example, a circular shape or an elliptical shape, and both surfaces may be the same shape, similar shape, or different shapes. For example, the shape of the embedded surface and the shape of the exposed surface can be easily made different by forming the heat radiating plate with a multilayer structure and joining plate materials having different shapes. Or you may shape | mold a heat sink so that the shape of an embedding surface and the shape of an exposed surface may differ, or may form a heat sink by cutting a raw material board.

(Modification 1-3)
The heat radiating plate of the first embodiment has been described as being made of silicon nitride. In addition, as a constituent material of the heat sink, for example, aluminum, aluminum alloy, copper, copper alloy, silver, silver alloy, metal materials such as iron and austenitic stainless steel, alumina (Al ₂ O ₃ ): 20-30 W / m About K, Aluminum nitride (AlN): 200-250W / m ・ K, Boron nitride (BN): 50-65W / m ・ K, Silicon carbide (SiC): 50-130W / m ・ K, etc. Non-metallic materials such as ceramics (numerical values are thermal conductivity) can be used. A heat sink using ceramics is lightweight, and a heat sink using a metal material has high heat dissipation.

In the case of a heat radiating plate made of a metal material, the insulating property between the coil and the heat radiating plate can be enhanced by providing a ceramic thin film having excellent insulating properties on the surface arranged close to the coil. At this time, the heat sink has an embedded surface made of the ceramic thin film and an exposed surface made of a metal material. Examples of the ceramic thin film include Si ₃ N ₄ , Al ₂ O ₃ , AlN, BN, SiC, and the like, and can be formed by a PVD method, a CVD method, or the like. Alternatively, the insulation between the coil and the heat radiating plate can be improved by fixing the heat radiating plate so that the constituent resin of the resin molded portion 4c is interposed between the coil and the heat radiating plate. The matters related to the modified example 1-3 can be applied to modified examples described later and the second embodiment.

(Modification 1-4)
In the first embodiment, the configuration in which the heat radiating plate 5 is disposed in contact with the installation surface disposed on the gantry side in the coil 3 has been described. In addition, to cover the outer periphery of the coil 3, a surface other than the installation surface in the coil 3, specifically, an upper surface (a surface from which the end of the winding 3w is pulled out in the coil 3 in FIG. If a configuration in which a separate heat sink is disposed in contact with or close to the side surface (the left and right surfaces in the coil 3 in FIG. 1A), a reactor having further excellent heat dissipation can be obtained. A separately prepared heat sink may also be fixed with the constituent resin of the resin molded portion 4c, and it is difficult to drop off because it has the same shape as the heat sink 5.

(Embodiment 2)
Next, a reactor that does not include a coil molded body will be described. FIG. 4 is a schematic perspective view of the reactor of the present invention, and FIG. 5 is a front view of the reactor. The reactor 20 is used by being directly attached to the gantry 100 filled with a refrigerant therein, the magnetic core 2, the coil 3 disposed on the outer periphery of the core 2, the core 2 and the coil 3 The resin cover part 4l which covers the outer periphery of this combination, and the heat sink 5 which is disposed on the outer periphery of the coil 3 and is fixed to the constituent resin of the resin cover part 4l. The feature of the reactor 20 is that it includes a heat radiating plate 5 having a specific shape as in the first embodiment. Hereinafter, a description will be given focusing on differences from the first embodiment.

[Magnetic core]
The magnetic core 2 is the same as the magnetic core provided in the reactor 10 of the first embodiment, and is formed in an annular shape by a pair of coil winding portions (not shown) and a pair of end cores 2e. Here, both the surface on the gantry 100 side of the end core 2e (the lower surface in FIG. 5, hereinafter referred to as the installation surface 2b) and the surface facing the installation surface 2b (the upper surface in FIG. 5) are coil windings. It protrudes from the surface of the turn part on the side of the gantry 100 and its opposite face, and is not flush with the coil winding part.

[coil]
The coil 3 includes a pair of coil elements formed by edgewise winding a covered flat wire as in the first embodiment. Here, each coil element is produced by a separate covered rectangular wire, and the end of the winding 3w forming each coil element is joined by welding or the like to form an integral coil.

[Insulator]
The assembly of the magnetic core 2 and the coil 3 is also provided with an insulator 6. The insulator 6 includes a cylindrical portion (not shown) that covers the outer periphery of the coil winding portion, and a pair of frame-like portions 6f that are in contact with the end face of the coil 3. If the cylindrical portion is configured to engage half-cut square tube pieces, the outer periphery of the coil winding portion can be easily covered. Each frame-like part 6f is a rectangular frame arranged at one end of the cylindrical part. Insulators such as PPS resin, polytetrafluoroethylene (PTFE) resin, and LCP can be used for the insulator.

[Resin coating part]
The combined body includes a resin coating portion 4l so as to cover the outer periphery thereof. Here, the resin coating portion 4l is formed by casting an epoxy resin so that the end of the winding 3w of the coil 3 is exposed after the assembly is manufactured. This resin coating portion 4l is a rectangular parallelepiped shape, the average thickness of the portion covering the magnetic core 2 and the coil 3 is uniform as 1 to 2 mm, the four corners are relatively thick, and the base 100 And an insertion hole 4b (FIG. 5) through which a bolt 7 for fixing the reactor 20 is inserted. The shape of the resin coating portion 4l and the thickness of the resin can be appropriately selected.

[Heatsink]
The reactor 20 includes the heat radiating plate 5 as in the first embodiment. The shape and the constituent material of the heat sink 5 are the same as those of the first embodiment, and are fixed so as to be in contact with the installation surface of the coil 3 by the constituent resin of the resin coating portion 4l. Here, as shown in FIG. 5, the heat sink 5 is arranged so that the rectangular inclined surface 53 faces the axial direction of the coil 3. That is, the heat radiating plate is horizontally rotated by 90 ° with respect to the arrangement position of the heat radiating plate according to the first embodiment so that the direction of the end face is changed. The heat sink 5 has a triangular portion formed by the embedded surface 51 and the inclined surface 53 functioning as a latching portion, and the resin-coated portion is formed by the triangular-shaped receiving portion 4n composed of the resin of the resin-coated portion 4l. It is firmly fixed to 4l and hard to fall off.

[Manufacture of reactors]
The reactor 20 having the above configuration can be formed as follows.

  First, the core piece and the gap material are fixed with an adhesive or the like to form a coil winding portion, and the tubular portion of the insulator is disposed on the outer periphery. Separately, the prepared coil 3 is placed in the coil winding portion where the cylindrical portion is arranged, and the frame-like portion 6f of the insulator 6 and the end core 2e are brought into contact with both end faces of the coil 3, so that the coil The frame-like portion 6f and the end core 2e are arranged so as to sandwich 3 and the end core 2e and the coil winding portion are joined with an adhesive or the like. Through this step, a combination of the magnetic core 2 and the coil 3 is obtained.

  The resin covering portion 4l is formed so as to cover the outer periphery of the obtained combined body, and the combined body and the heat sink 5 are integrated with the constituent resin of the resin covering portion 4l. The exposed surface 52 of the heat sink 5 and the end of the winding 3w are exposed from the resin coating 4l. The reactor 20 is assembled by the above process.

  The obtained reactor 20 is attached to the gantry 100 by placing the installation surface 2b of the end core 2e and the exposed surface 52 of the heat sink 5 in contact with the gantry 100 and tightening the bolts 7. If grease or the like is applied to the installation surface 2b or the exposed surface 52 very thinly (several tens of μm), the end core 2e and the heat sink 5 are easily brought into close contact with the gantry 100.

[effect]
Similarly to the reactor 10 of the first embodiment, the reactor 20 having the above configuration is provided with the heat radiating plate 5 and thus has excellent heat dissipation even when the case is omitted. In particular, the heat sink 5 is not easily dropped because the hook of the heat sink 5 is hooked on the constituent resin (receiving part 4n) of the resin coating part 4l. It is expected that it can be utilized for. Further, when the resin coating portion 4l is molded, the heat sink 5 is fixed to the combined body of the magnetic core 2 and the coil 3 by this constituent resin, so that the fixing work is easy and the assembly workability of the reactor is excellent. Furthermore, the reactor 20 does not require a fixing member such as a bolt for fixing the heat radiating plate 5, and the number of parts and work processes can be reduced.

  In addition, the reactor 20 has a configuration in which the end core 2e of the magnetic core 2 and the heat sink 5 are in direct contact with the gantry 100, so that the heat of the magnetic core 2 and the coil 3 can be efficiently transmitted to the gantry 100, and the heat dissipation Even better. Further, by forming the end core 2e so as to protrude from the coil winding portion, the end core of the conventional reactor in which the outer peripheral surface of the end core and the outer peripheral surface of the coil winding portion are flush with each other is provided. If the cross-sectional area is equal to the cross-sectional area of the end core 2e, the reactor 20 can make the length of the magnetic core (the length in the axial direction of the coil) shorter than the conventional reactor. Therefore, the reactor 10 has a smaller mounting area with respect to the gantry 100 and is smaller than the conventional reactor.

  In addition, the reactor 20 includes a resin coating portion 4l made of an insulating resin, so that (1) the magnetic core 2 and the coil 3 can be handled integrally, and (2) the magnetic core 2 can be reinforced. 3) The magnetic core 2 and the coil 3 can be protected from the external environment, and (4) insulation with surrounding members can be secured.

  Further, the reactor 20 can be easily attached to the gantry 100 by providing the insertion hole 4b through which the bolt 7 is inserted into the resin coating portion 4l. In particular, in the reactor 20, the resin in the portion where the insertion hole 4b is provided is thickened, and the resin coating portion 4l is not easily cracked by the stress when the bolt 7 is tightened. In addition, since the location where the insertion hole 4b is provided is a location where no combination exists, it is possible to reduce a decrease in heat dissipation due to the presence of a thick resin portion.

(Modification 2-1)
The heat radiating plate 5 of the second embodiment is a tapered surface in which two opposing end surfaces 5e taper from the embedded surface 51 toward the exposed surface 52. As other heat sinks, like the reactor 30 shown in FIG. 6, the heat sink 5A having a step in the end face region (as described in Modification 1-2 (FIG. 3 (A))) and FIGS. The heat sinks 5B to 5D shown in (D) can be used as appropriate.

  Note that the above-described embodiments and modifications can be appropriately changed without departing from the gist of the present invention, and are not limited to the above-described configuration.

  Since the reactor of the present invention has excellent heat dissipation and is small, it is suitable for a component part of a power conversion device such as an in-vehicle DC-DC converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle. Can be used. The coil molded object of this invention can be utilized suitably for the component of the said reactor.

1 Coil compact 2 Magnetic core 2e End core 2c Coil winding part
2m Core piece 2g Gap material 2b Installation surface 3 Coil 3w Winding
3r Unwinding part 4c Resin molding part 4l Resin coating part 4h Hollow hole 4b Insertion hole
4n, 4An, 4Bn, 4Cn, 4Dn Receiver 5,5A, 5B, 5C, 5D Heat sink 5e, 5De End face
51,51A, 51B, 51C, 51D Buried surface 52,52A, 52C, 52D Exposed surface
53,53B, 53D Inclined surface 54 Protrusion 6 Insulator 6f Frame
7 bolt 10,20,30 reactor 100 mount

Claims (6)

A coil molded body used for a reactor in which a coil formed by spirally winding a winding is disposed on the outer periphery of a magnetic core,
A resin molded part for holding the coil in a compressed state than its free length;
A heat sink disposed on the outer periphery of the coil and fixed by a resin component of the resin molded portion;
The heat dissipation plate includes an embedded surface and an exposed surface, the embedded surface is a surface that is disposed on the coil side and is not exposed from the resin molding portion, and the exposed surface is opposed to the embedded surface, and It is the surface exposed from the resin molded part,
In the heat sink, a coil molded body having a hook portion that prevents the heat sink from falling off by being caught by a constituent resin of the resin molding portion in an end surface region between the embedded surface and the exposed surface. . The coil molded body according to claim 1,
A reactor comprising a magnetic core disposed on an inner periphery of the coil. A reactor comprising a magnetic core and a coil disposed on the outer periphery of the core,
A resin coating covering the outer periphery of the combination of the magnetic core and the coil;
A heat sink disposed on the outer periphery of the coil and fixed by a constituent resin of the resin coating portion;
The heat radiating plate includes an embedded surface and an exposed surface, the embedded surface is disposed on the coil side and is a surface that is not exposed from the resin coating portion, and the exposed surface is opposed to the embedded surface, The surface exposed from the resin coating,
The reactor, wherein the heat sink has a hook portion that prevents a heat sink from falling off by being caught by a constituent resin of the resin coating portion in an end surface region between the embedded surface and the exposed surface. The heat radiating plate is a rectangular plate, and of the end surfaces of the rectangular plate, two opposing end surfaces are tapered surfaces that taper from the embedded surface toward the exposed surface, and the remaining two end surfaces are , An inclined surface inclined with respect to the buried surface,
4. The reactor according to claim 2, wherein the hooking portion is a portion formed by the embedded surface and the inclined surface.   3. The reactor according to claim 2, wherein an outer periphery of a combination of the coil molded body and the magnetic core is not covered with a resin.   6. The reactor according to any one of claims 2 to 5, wherein a metal case is not provided on an outer periphery of the reactor.

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