JP2012204778A - Reactor and reactor case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor and a reactor case capable of improving assembly workability.SOLUTION: A reactor 1 includes an assembly 10 having a coil 2 obtained by winding wire and a magnetic core 3 on which the coil 2 is placed, and a case 4 for accommodating the assembly 10. The case 4 includes a bottom plate part 40 and a side wall part 41 that is a member separated from the bottom plate part 40. The bottom plate part 40 is a member to be brought into contact with an installation object when the reactor 1 is installed in the installation object. The side wall part 41 is integrated with the bottom plate part 40 using a fixing material and placed so as to surround the assembly 10. A positioning groove 45 is formed on the inner face of the bottom plate part 40 so as to position at least one of the coil 2 and the magnetic core 3.

Description

  The present invention relates to a reactor used 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, and a reactor case used for the reactor. In particular, the present invention relates to a reactor excellent in assembly workability.

  A reactor is one of the parts of a circuit that performs a voltage step-up operation or a voltage step-down operation. For example, Patent Document 1 discloses a reactor used for a converter mounted on a vehicle such as a hybrid vehicle. The reactor includes a coil formed by winding a winding, an annular magnetic core in which the coil is disposed, a case that houses a combination of the coil and the magnetic core, and a sealing resin that is filled in the case. Prepare. A terminal fitting is attached to the end of the winding constituting the coil, and the coil is supplied with power from an external device such as a power source through the terminal fitting. This reactor is generally used by being fixed to a cooling base in order to cool a coil that generates heat when energized.

  The case is typically an aluminum die-cast product, and is used as a heat dissipation path for fixing heat to the coil and the like by being fixed to the cooling base.

JP 2010-050408 A

  In the case, a bottom plate portion that forms the bottom surface of the case inner surface and a side wall portion that forms the side wall surface of the case inner surface are integrally formed in advance. Since the coil is usually made of copper and the magnetic core is usually made of iron, the combination is heavy. Therefore, in a reactor having a conventional aluminum case, when the assembly is assembled to the case, the assembly, which is a heavy object, is lifted and inserted from the opening of the case, resulting in poor assembly workability.

  By the way, it is possible to omit the case. However, when the case is omitted, the coil and the magnetic core are exposed, and thus the coil and the magnetic core cannot be protected at all from the external environment such as dust and moisture and mechanical external force such as impact.

  Accordingly, one of the objects of the present invention is to provide a reactor having excellent assembly workability. Another object of the present invention is to provide a reactor case that improves assembly workability.

  The present invention has (1) a structure in which the case is divided into a bottom plate portion and a side wall portion, and (2) at least one of a coil and a magnetic core on the inner surface of the bottom plate portion (the surface that becomes the inner surface side when the case is used). The above-mentioned object is achieved by adopting a configuration in which positioning grooves for positioning are formed.

  The reactor of the present invention includes a combination having a coil formed by winding a winding and a magnetic core on which the coil is disposed, and a case for housing the combination. The case includes a bottom plate portion and a side wall portion which is a member independent of the bottom plate portion. The bottom plate portion is a member that contacts the installation target when the reactor is installed on the installation target. The side wall portion is integrated with the bottom plate portion by a fixing material, and is disposed so as to surround the periphery of the combination. And the positioning groove which positions at least one of the said coil and the said magnetic core is formed in the inner surface of the said baseplate part, It is characterized by the above-mentioned.

  The reactor case according to the present invention accommodates a combined body having a coil formed by winding a coil and a magnetic core on which the coil is disposed, and the bottom plate portion and the bottom plate portion are independent members. With some sidewalls. The bottom plate portion is a member that contacts the installation target when the reactor is installed on the installation target. The side wall portion is integrated with the bottom plate portion by a fixing material, and is disposed so as to surround the periphery of the combination. And the positioning groove which positions at least one of the said coil and the said magnetic core is formed in the inner surface of the said baseplate part, It is characterized by the above-mentioned.

  According to the reactor and the reactor case of the present invention described above, it is possible to improve the assembly workability by adopting a structure in which the case is divided into the bottom plate portion and the side wall portion. Specifically, after placing the combined body on the inner surface of the bottom plate portion with the side wall portion removed and assembling the combined body to the bottom plate portion, the side wall portion is disposed and the bottom plate portion and the side wall portion are integrated. By doing so, the reactor can be assembled. Therefore, unlike the conventional case, it is not necessary to lift the heavy assembly to the opening of the case, and the assembly workability can be improved.

  In addition, the positioning groove for positioning at least one of the coil and the magnetic core is formed on the inner surface of the bottom plate portion, so that when the combination is placed on the bottom plate portion, the combination can be positioned accurately and easily. it can. When the inner surface of the bottom plate portion is flat, it is difficult to accurately position the combination body with respect to the bottom plate portion when placing the combination body on the bottom plate portion, and this positioning needs to be performed using a jig or the like. On the other hand, when the positioning groove is formed on the inner surface of the bottom plate part, it is possible to easily position at least one of the coil and the magnetic core without positioning jigs, so that the assembly can be positioned accurately and easily. Therefore, the assembly workability can be further improved.

  In addition, according to the reactor and the reactor case of the present invention described above, the bottom plate portion and the side wall portion are separate members, and each can be manufactured separately, so that the degree of freedom in assembly is great. For example, the assembly can be placed on the inner surface of the bottom plate portion with the side wall portion removed, and a bonding layer for fixing the coil to the inner surface of the bottom plate portion with the side wall portion removed can be formed. Here, in the conventional case in which the bottom plate portion and the side wall portion are integrally formed and cannot be separated, the side wall portion obstructs and it is difficult to form a bonding layer on the inner surface of the bottom plate portion (the bottom surface of the case). Therefore, in the reactor and the reactor case of the present invention, it is easy to form a bonding layer on the bottom plate portion, and in this respect as well, improvement in assembly workability can be expected. Alternatively, when producing an integrated object in which the terminal fitting is fixed to the side wall portion, the terminal fitting is integrally formed by injection molding or the like when the sidewall portion is produced, or by using a fastening member such as a bolt. Or can be made. When integrally molded by injection molding or the like, the number of parts and the number of assembling processes are reduced, and improvement in productivity can be expected. When a tightening member such as a bolt is used, it is easy to replace or change parts such as terminal fittings, which is excellent in terms of maintainability and ease of design change. In addition, in the reactor of the present invention, by providing the case, the coil and the magnetic core can be protected from the external environment and mechanical external force.

  As an example of the case where the bottom plate portion and the side wall portion constituting the case are formed of different materials, the bottom plate portion is formed of a metal material, and the side wall portion is formed of an insulating resin material. When the bottom plate portion is formed of a metal material, the thermal conductivity is high and the heat dissipation can be improved. Examples of the metal material include metals such as aluminum and magnesium, alloys thereof, and stainless steel. In particular, aluminum or an aluminum alloy has high thermal conductivity (aluminum: 237 W / m · K) and is lightweight, so that heat dissipation can be improved and weight can be reduced.

  On the other hand, since the side wall portion is formed of an insulating resin material, the size can be reduced. In a reactor having a conventional aluminum case, it is necessary to electrically insulate the coil from the case, and there is usually a relatively large gap between the coil and the inner surface of the case to ensure an electrical insulation distance. Provided. Therefore, it is difficult to reduce the size of the conventional reactor from the viewpoint of securing this insulation distance. On the other hand, when the side wall portion is formed of an insulating resin material, the side wall portion can be disposed close to the coil, and the size can be reduced. Further, if an insulating resin material that is lighter than the metal material is selected, further weight reduction can be achieved. Examples of the insulating resin material include polybutylene terephthalate (PBT) resin, urethane resin, polyphenylene sulfide (PPS) resin, and acrylonitrile-butadiene-styrene (ABS) resin. In addition, when a side wall part is formed with an electroconductive and nonmagnetic metal material, while improving heat dissipation, it functions as a magnetic shield, Therefore A leakage magnetic flux can be suppressed.

  As one form of the reactor of this invention, the said assembly is accommodated in the said case so that the axial direction of the said coil may be parallel to the inner surface of the said baseplate part, and the said positioning groove is orthogonal to the axial direction of the said coil In the cross section in the direction, the shape may be a shape along the outer peripheral surface of the coil facing the inner surface of the bottom plate portion.

  According to this configuration, since the outer peripheral surface of the coil faces the inner surface of the bottom plate portion and the positioning groove has a shape along the outer peripheral surface of the coil, it is only easy to position the coil (union) with respect to the bottom plate portion. In addition, since the distance between the coil that generates heat when the reactor is used and the bottom plate portion is shortened, the heat of the coil can be efficiently transmitted to the bottom plate portion. Therefore, the heat generated in the coil can be efficiently radiated to the installation target such as the cooling base via the bottom plate portion, so that the heat dissipation is improved.

  As one form of the reactor of this invention, it is mentioned that the said baseplate part is a metal plate in which the said positioning groove was formed by press work.

  According to this configuration, since the positioning groove of the bottom plate portion is formed by pressing, an improvement in productivity can be expected. The positioning groove can be formed by pressing the plate material, by cutting, or by integral molding if the bottom plate portion is a die-cast product. In particular, when positioning grooves are formed on a plate by pressing, the plate is easy to obtain due to its high versatility, and the plate is widely pressed, reducing costs and improving productivity. Can be achieved. Furthermore, since the bottom plate portion is a metal plate, the thermal conductivity is high and the heat dissipation is improved.

  Here, when a metal plate in which positioning grooves are formed by pressing is used for the bottom plate portion, the thickness of the bottom plate portion (excluding the uneven portions forming the positioning grooves) is, for example, 1 mm or more and 5 mm or less, preferably 2 mm or more, The height of the positioning groove is 10% or more and 100% or less, preferably 50% or more of the thickness of the bottom plate portion. By making the thickness of the bottom plate part 1 mm or more, preferably 2 mm or more, it is easy to ensure the strength. By making the thickness of the bottom plate part 5 mm or less, it is possible to reduce the thermal resistance and to ensure heat dissipation. In addition, by making the positioning groove height 10% or more, preferably 50% or more of the thickness of the bottom plate part, it is easy to ensure the function as the positioning groove and prevent the positioning groove from disappearing due to the formation of the bonding layer. Easy to do. By setting the height of the positioning groove to 100% or less of the thickness of the bottom plate portion, it is easy to form the positioning groove by press working. The height of the positioning groove is, for example, 0.1 mm to 4.5 mm, preferably 1 mm or more.

  The said joining layer is arrange | positioned at the side which contact | connects the said coil, and it is mentioned as a multilayer structure provided with the contact bonding layer which consists of an insulating adhesive agent, and the thermal radiation layer arrange | positioned at the side which contact | connects the said baseplate part. In this case, the coil is fixed to the bottom plate portion by the bonding layer including the heat dissipation layer. That is, a surface (hereinafter referred to as a coil installation surface) on the installation side when the reactor is installed on the installation target in the coil is close to, preferably in contact with, the heat dissipation layer. Therefore, the heat of the coil is efficiently transmitted to the heat dissipation layer, and heat can be efficiently radiated to the installation target such as the cooling base via the heat dissipation layer, so that the heat dissipation is improved. In particular, since this bonding layer includes an adhesive layer made of an insulating adhesive at least on the side in contact with the coil, even if the heat dissipation layer and the bottom plate portion are formed of a conductive metal material, the coil and the bottom plate portion Can be electrically insulated. Therefore, the thickness of the bonding layer including the heat dissipation layer can be reduced, and from this point, the heat resistance can be reduced and the heat dissipation can be improved.

  In addition, since the bonding layer includes the heat dissipation layer, as described above, it is possible to efficiently dissipate heat through at least the coil installation surface through the heat dissipation layer.For example, when filling the case with a sealing resin, Even if a resin having inferior thermal conductivity is used as the sealing resin, heat dissipation can be ensured by the heat dissipation layer. Therefore, the range of selection of the sealing resin to be used can be expanded. For example, even if a resin that does not contain a filler for imparting thermal conductivity is used for the sealing resin, it is easy to ensure heat dissipation. Or even if it is a case where it does not fill with sealing resin, it can have sufficient heat dissipation by a heat dissipation layer.

  Furthermore, as described above, by reducing the thickness of the bonding layer including the heat dissipation layer, the distance between the coil installation surface and the inner surface of the bottom plate portion can be reduced, and further miniaturization can be achieved.

  The bonding layer may have a single layer structure made of an insulating material (eg, an insulating adhesive) or a multilayer structure including a layer made of an insulating material. With a single layer structure, the bonding layer can be easily formed. On the other hand, with a multilayer structure, defects such as pinholes are unlikely to occur, and insulation can be easily ensured. In particular, when a multilayer structure of the same material is used, the thickness per layer can be reduced and a bonding layer can be easily formed. On the other hand, a multi-layer structure made of different materials can have a plurality of characteristics such as insulation between the coil and the bottom plate, adhesion with the coil, and heat dissipation from the coil to the bottom plate. For example, a bonding layer having a multilayer structure including the adhesive layer and the heat dissipation layer as described above may be used. For the adhesive layer, for example, an adhesive (for example, an epoxy-based adhesive) having better adhesion than the heat dissipation layer is used, and for the heat dissipation layer, for example, a material (for example, alumina) having better thermal conductivity than the adhesive layer. By using the filler-containing epoxy adhesive), the adhesion with the coil can be improved, and the heat of the coil can be efficiently transmitted to the heat dissipation layer by this adhesion. Of course, the type of adhesive used in the adhesive layer and the heat dissipation layer (epoxy adhesive in the above example) may be different. In addition, since the adhesive layer is made of an insulating adhesive, even if the adhesive layer is thin, sufficient insulation is ensured between the coil and the bottom plate, and the heat of the coil is transferred to the heat dissipation layer by this thinning. easy. Furthermore, if the heat dissipation layer is also formed of an insulating material, the insulating property can be further improved, and even if the thickness of each layer is reduced, it has a multilayer structure, so that it can have a sufficient insulating property. In addition, an insulating sheet may be used for at least one of the adhesive layer and the heat dissipation layer.

  Here, when the bonding layer has a multilayer structure, the thickness and the number of layers per layer may be appropriately selected. The thicker the total thickness, the higher the insulating property, and the thinner, the higher the heat dissipation. When the material of each layer is a material excellent in insulation, sufficient heat dissipation and insulation can be obtained even if each layer is thin and the number of layers is small. For example, a bonding layer having a total thickness of less than 2 mm, further 1 mm or less, particularly 0.5 mm or less can be obtained.

  In the multi-layer joint layer including the adhesive layer and the heat dissipation layer as described above, at least a part of the heat dissipation layer is formed of a material having a thermal conductivity of more than 2 W / m · K from the viewpoint of improving heat dissipation. It is preferable. For example, an epoxy-based adhesive containing an alumina filler is excellent in both insulation and heat dissipation, and can satisfy a thermal conductivity of 3 W / m · K or more. In this case, since the entire bonding layer is made of an insulating material, the insulating property can be further improved. An adhesive containing the filler as described above may be used for the adhesive layer.

  The reactor and the reactor case according to the present invention have a structure in which the case is divided into a bottom plate portion and a side wall portion, and positioning grooves are formed on the inner surface of the bottom plate portion, thereby improving the assembly workability. it can.

It is a schematic perspective view which shows the reactor of embodiment. It is a disassembled perspective view which shows the outline of the reactor of embodiment. It is a disassembled perspective view which shows the outline of the assembly of the coil and magnetic core which are provided in the reactor of embodiment. It is a figure which shows the outline of the baseplate part provided in the reactor of embodiment, and is sectional drawing of the direction orthogonal to the axial direction of a coil.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The same reference numerals in the figure indicate the same names. In the following description, the side that becomes the installation side when the reactor is installed on the installation target is described as the lower side, and the opposite side (opposite side) is described as the upper side.

"overall structure"
The reactor 1 includes a combined body 10 of a coil 2 formed by winding a winding 2w and a magnetic core 3 on which the coil 2 is disposed, and a case 4 that houses the combined body 10. The case 4 is a box that is open on one side, and is typically filled with a sealing resin (not shown), and the assembly 10 is embedded in the sealing resin except for the end 2e of the winding. . A terminal fitting 8 is joined to the end 2e of each winding, and power is supplied to the coil 2 via the terminal fitting 8. The reactor 1 is characterized in that the case 4 is configured by combining a plurality of independent members, and that a positioning groove 45 (see FIG. 2) is formed in the bottom plate portion 40 constituting the case 4. . Hereinafter, each component will be described in more detail.

[Union]
[coil]
The coil 2 will be described with reference to FIGS. The coil 2 includes a pair of coil elements 2a and 2b formed by spirally winding a single continuous winding 2w having no joint part, and a coil connecting part 2r for connecting both the coil elements 2a and 2b. . Each coil element 2a, 2b has the same number of turns, and the shape (end face shape) viewed from the axial direction is substantially rectangular (rectangular shape with rounded corners). These coil elements 2a and 2b are arranged side by side so that their axial directions are parallel, and a part of the winding 2w is U-shaped on the other end side of the coil 2 (the back side in FIG. 2). A coil connecting portion 2r is formed by bending. With this configuration, the winding directions of both coil elements 2a and 2b are the same.

  The winding 2w is preferably a coated wire having an insulating coating made of an insulating material on the outer periphery of a conductor made of a conductive material such as copper, aluminum, or an alloy thereof. Here, a coated rectangular wire is used in which the conductor is made of a copper rectangular wire and the insulating coating is made of enamel (typically polyamideimide resin). The thickness of the insulating coating is preferably 20 μm or more and 100 μm or less, and the thicker the pinholes can be reduced, the electrical insulation can be enhanced. Both coil elements 2a, 2b are formed in a hollow rectangular tube shape by winding the above-mentioned covered rectangular wire edgewise. As the winding 2w, in addition to a conductor made of a flat wire, various shapes such as a circular shape, an elliptical shape, and a polygonal shape can be used. The rectangular wire is easy to form a coil with a high space factor as compared with the case where a round wire having a circular cross section is used. When a rectangular wire is used, the surface on the installation side when the reactor 1 is installed on the installation target in the coil 2 (hereinafter referred to as a coil installation surface; the lower surface in FIGS. 2 and 3) is equal to the thickness of the rectangular wire. Since it substantially has an area based on the product of the number of turns, it is easy to ensure a wide contact area with a bonding layer 42 to be described later, compared to the case where a round wire is used. Furthermore, the flat wire is easy to secure a bonding area with the terminal fitting 8 in the same shape. In addition, it is also possible to form each coil element by separate windings and join the ends of the windings forming each coil element by welding or soldering to form an integrated coil.

  Both end portions 2e of the winding forming the coil 2 are appropriately extended from the turn forming portion on one end side (the front side in FIG. 2) of the coil 2 and pulled out of the case 4 (see FIG. 1). A terminal fitting 8 made of a conductive material is connected to both ends 2e of the drawn-out winding on a conductor portion exposed by peeling off the insulation coating. An external device (not shown) such as a power source for supplying power to the coil 2 is connected via the terminal fitting 8.

[Magnetic core]
The magnetic core 3 will be described with reference to FIG. The magnetic core 3 includes a pair of inner core portions 31 where the coil elements 2a and 2b are respectively disposed, and a pair of outer core portions 32 where the coil 2 is not disposed and is exposed from the coil 2. Here, each inner core portion 31 has a rectangular parallelepiped shape (here, rounded corners), and each outer core portion 32 has a prismatic body having a pair of trapezoidal surfaces. The magnetic core 3 has an outer core portion 32 disposed so as to sandwich the inner core portion 31 that is spaced apart, and the end surface 31e of each inner core portion 31 and the inner end surface 32e of the outer core portion 32 are in contact with each other to form an annular shape. Formed. The inner core portion 31 and the outer core portion 32 form a closed magnetic path when the coil 2 is excited.

  The inner core portion 31 is a laminated body configured by alternately laminating core pieces 31m made of a magnetic material and gap members 31g typically made of a nonmagnetic material, and the outer core portion 32 is made of a magnetic material. A core piece consisting of The core piece 31m and the gap material 31g can be joined and integrated by, for example, applying an adhesive or winding an adhesive tape. Further, an adhesive may be used for forming the inner core portion 31, and an adhesive may not be used for joining the inner core portion 31 and the outer core portion 32. Here, no adhesive is used for joining the core piece 31m and the gap material 31g.

  As each core piece, a molded body using magnetic powder or a laminated body in which a plurality of magnetic thin plates (for example, electromagnetic steel sheets) having an insulating coating are laminated can be used. Examples of the molded body include iron group metals such as Fe, Co, and Ni, Fe-based alloys such as Fe-Si, Fe-Ni, Fe-Al, Fe-Co, Fe-Cr, and Fe-Si-Al, and rare earth metals. Compacts using powders made of soft magnetic materials such as magnetic materials and amorphous magnetic materials, sintered products obtained by sintering the above powders after press molding, and moldings such as injection molding and cast molding of the above powder and resin mixture A hardened body is mentioned. In addition, a ferrite core which is a sintered body of a metal oxide can be used. The molded body can easily form various three-dimensional magnetic cores.

  As the green compact, a powder having an insulating coating on the surface of the powder made of the soft magnetic material can be suitably used. In this case, after the powder is molded, heat treatment is performed at a temperature lower than the heat resistance temperature of the insulating coating. It is obtained by applying. Typically, the insulating coating includes a silicone resin or a phosphate.

  The material of the inner core portion 31 and the material of the outer core portion 32 may be different. For example, when the inner core portion 31 is the above-mentioned green compact or the above laminated body and the outer core portion 32 is the above-mentioned molded and hardened body, the saturation magnetic flux density of the inner core portion 31 can be higher than that of the outer core portion 32. Here, each core piece is a compacted body of soft magnetic powder containing iron such as iron or steel.

  The gap material 31g is a plate-like material disposed in a gap provided between the core pieces 31m for adjusting the inductance, and is a material having a lower magnetic permeability than the core piece, such as alumina, glass epoxy resin, and unsaturated polyester. Typically, it is made of a nonmagnetic material (in some cases, an air gap). In addition, if a mixed material in which magnetic powder (for example, ferrite, Fe, Fe-Si, Sendust) is dispersed in a nonmagnetic material such as ceramics or phenol resin is used for the gap material 31g, the leakage magnetic flux in the gap portion can be reduced. Can do.

  The number of core pieces and gap members can be appropriately selected so that the reactor 1 has a desired inductance. Moreover, the shape of a core piece or a gap material can be selected suitably. Here, the inner core portion 31 shows a form composed of a plurality of core pieces 31m and a plurality of gap members 31g. However, the inner core part 31 may have one gap member or no gap member depending on the material of the core pieces. It is also possible to adopt a form. In addition, here, each outer core portion 32 shows a form constituted by a single core piece, but may be constituted by a plurality of core pieces. In the case where the core piece is formed of a compacted body, when the inner core portion and the outer core portion are configured by a plurality of core pieces, each core piece can be made small, and thus the moldability is excellent.

  In addition, if the outer core of the inner core portion 31 is provided with a coating layer made of an insulating material, the insulation between the coil 2 and the inner core portion 31 can be enhanced. The said coating layer is provided by arrange | positioning a heat shrinkable tube, a normal temperature shrinkable tube, an insulating tape, insulating paper, etc., for example. In addition to enhancing insulation by placing the shrinkable tube on the outer periphery of the inner core 31 or attaching insulating tape, the core piece and the gap material are integrated without using an adhesive. You can also Moreover, it can replace with the insulator 5 (circumferential wall part 51) mentioned later, and these shrinkable tubes and insulating tape can be utilized.

  In the magnetic core 3 shown in this example, the installation side surface of the inner core portion 31 and the installation side surface of the outer core portion 32 are not flush with each other. Specifically, when the reactor 1 is installed on the installation target, a surface on the outer core portion 32 on the installation side (hereinafter referred to as a core installation surface; the lower surface in FIG. 3) is a surface on the inner core portion 31 on the installation side. Than protruding. Here, the core installation surface of the outer core portion 32 and the coil installation surface of the coil 2 are flush with each other, and the surface facing the installation side surface of the inner core portion 31 (upper surface in FIG. 3) In a state where the outer core portion 32 is installed on the installation target so that the surface facing the core installation surface of the outer core portion 32 (upper surface in FIG. 3) is flush with the installation target, The length in the direction perpendicular to the surface (here, the length perpendicular to the axial direction of the coil 2 and the vertical direction in FIG. 3) is adjusted. Therefore, the magnetic core 3 has a gate shape when seen through from the side in a state where the reactor 1 is installed. Further, since the core installation surface and the coil installation surface are flush with each other, not only the coil installation surface of the coil 2 but also the core installation surface of the magnetic core 3 should be in contact with a bonding layer 42 (see FIG. 2) described later. Can do. Further, in a state where the magnetic core 3 is assembled in an annular shape, the side surface of the outer core portion 32 (the front side and the back surface in FIG. 3) protrudes outward from the side surface of the inner core portion 31. Therefore, the magnetic core 3 is H-shaped when seen through from the upper surface or the lower surface in a state where the reactor is installed (in a state where the lower side is the installation side in FIG. 3). Such a three-dimensional magnetic core 3 can be easily formed by forming a compacted body, and the outer core portion 32 can also use a portion protruding from the inner core portion 31 as a magnetic flux path. Can do. Further, since the core installation surface and the coil installation surface are flush with each other, the installation surface of the combined body 10 is large, and the combined body 10 can be stably installed.

[Insulator]
As shown in FIG. 3, the combined body 10 includes an insulator 5 between the coil 2 and the magnetic core 3 to enhance insulation between the coil 2 and the magnetic core 3. The insulator 5 includes a peripheral wall portion 51 disposed on the outer periphery of the inner core portion 31 and a pair of frame-like portions 52 that are in contact with the end surface of the coil 2 (surface in which the turn of the coil element appears to be annular).

  The peripheral wall portion 51 is interposed between the inner peripheral surface of the coil 2 and the outer peripheral surface of the inner core portion 31, and insulates the coil 2 from the inner core portion 31. Here, the peripheral wall 51 is constituted by a pair of divided pieces 511 and 512 having a cross section. The divided pieces 511 and 512 are not in contact with each other, and the divided pieces 511 and 512 are arranged only on a part of the outer peripheral surface of the inner core portion 31 (here, mainly the surface on the installation side of the inner core portion 31 and its opposite surface). It is said. The peripheral wall portion 51 may be a cylindrical body disposed along the entire circumference of the outer peripheral surface of the inner core portion 31. If the insulation distance between the coil 2 and the inner core portion 31 can be secured, FIG. As shown in the figure, a part of the outer peripheral surface of the inner core portion 31 may not be covered by the peripheral wall portion 51. In addition, here, the peripheral wall 51 uses a window provided with a window penetrating the front and back.

  Since a part of the inner core portion 31 is exposed from the peripheral wall portion 51, the material of the insulator 5 can be reduced. Further, in the embodiment including the sealing resin, the inner core portion 31 is configured such that the divided pieces 511, 512 having the window portion are configured such that a part of the outer peripheral surface of the inner core portion 31 is not covered by the peripheral wall portion 51. In addition to increasing the contact area between the sealing resin and the sealing resin, bubbles are easily removed when the sealing resin is poured, and the reactor 1 is excellent in manufacturability.

  Each frame-like portion 52 is interposed between the end surface of the coil 2 and the inner end surface 32e of the outer core portion 32, and insulates the coil 2 from the outer core portion 32. Each frame-like portion 52 is a B-shaped body having a flat plate-like main body portion and a pair of openings through which the inner core portions 31 are inserted. Here, in order to facilitate the insertion of the inner core portion 31, a short cylindrical portion that continues from the opening of the main body portion and protrudes toward the inner core portion 31 is provided. In addition, the coil connection part 2r is placed on one (right side in FIG. 3) of the frame-like part 52, and a pedestal 52p for insulating the coil connection part 2r and the outer core part 32 is provided.

  As a constituent material of the insulator 5, insulating resin materials such as polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin, polybutylene terephthalate (PBT) resin, and liquid crystal polymer (LCP) can be used. The insulator 5 may not be provided.

〔Case〕
Case 4 will be described with reference to FIG. The case 4 in which the combined body 10 of the coil 2 and the magnetic core 3 is housed includes a flat bottom plate portion 40 and a frame-like side wall portion 41 standing on the bottom plate portion 40. Here, the assembly 10 is housed in the case 4 so that the axial direction of the coil 2 (coil elements 2a, 2b) is parallel to the inner surface of the bottom plate portion 40. Further, in the case 4, the bottom plate portion 40 and the side wall portion 41 are not integrally formed, and are independent members, and are integrated by a fixing material, and a positioning portion 45 is formed on the bottom plate portion 40. Each of them is characterized by having a bonding layer 42 on the bottom plate portion 40.

[Bottom plate]
The bottom plate portion 40 is a rectangular plate and comes into contact with the wetland object when the reactor 1 is installed on the installation object. In the example illustrated in FIG. 2, an installation state in which the bottom plate portion 40 is downward is shown, but there may be an installation state in which the bottom plate portion 40 is upward or sideward. In the bottom plate portion 40, when the case 4 is assembled, a positioning groove 45 is formed on the inner surface which becomes the inside of the case, and a bonding layer 42 is provided. The outer shape of the bottom plate portion 40 can be selected as appropriate. Here, the bottom plate portion 40 has attachment portions 400 protruding from the four corners, and the outer shape thereof is a shape along the outer shape of the side wall portion 41 described later. When the case 4 is configured by combining the bottom plate portion 40 and the side wall portion 41, the mounting portion 400 overlaps with the mounting portion 411 of the side wall portion 41. Each mounting portion 400 is provided with a bolt hole 400h through which a bolt (not shown) for fixing the case 4 to the installation target is inserted. The bolt hole 400h is provided so as to be continuous with a bolt hole 411h of the side wall 41 described later. As the bolt holes 400h and 411h, any of through-holes not subjected to threading and threaded holes subjected to threading can be used, and the number and the like can be appropriately selected.

  Alternatively, the side wall portion 41 may not have the attachment portion, and only the bottom plate portion 40 may have the attachment portion 400. In the case of this form, the outer shape of the bottom plate portion 40 is formed so that the attachment portion 400 of the bottom plate portion 40 protrudes from the outer shape of the side wall portion 41. Alternatively, only the side wall portion 41 may have the attachment portion 411 and the bottom plate portion 40 may have no attachment portion. In the case of this form, the outer shape of the side wall portion 41 is formed such that the attachment portion 411 of the side wall portion 41 protrudes from the outer shape of the bottom plate portion 40.

[Sidewall]
The side wall portion 41 is a rectangular frame-like body, and when the case 4 is assembled by closing one opening portion with the bottom plate portion 40, the side wall portion 41 is disposed so as to surround the assembly 10 and the other opening portion is opened. The Here, the side wall 41 has a rectangular shape along the outer shape of the bottom plate portion 40 when the reactor 1 is installed on the installation target, and the open side region is magnetic with the coil 2. It is a curved surface shape along the outer peripheral surface of the combination 10 with the core 3. In the assembled state of the case 4, the outer peripheral surface of the coil 2 and the inner surface of the side wall 41 are close to each other, and the distance between the outer peripheral surface of the coil 2 and the inner surface of the side wall 41 is about 0 mm to 1.0 mm. narrow. In addition, here, in the region on the opening side of the side wall portion 41, a bowl-shaped portion is provided so as to cover the trapezoidal surfaces of the both outer core portions 32 of the combined body 10. In the combined body 10 housed in the case 4, the coil 2 is exposed as shown in FIG. 1, and the magnetic core 3 is substantially covered with the case 4. By providing the hook-shaped part, (1) Improvement of vibration resistance, (2) Improvement of rigidity of case 4 (side wall part 41), (3) Protection from the external environment and mechanical external force of the assembly 10 Various effects such as are obtained. The hook-shaped portion may be omitted, and both the coil 2 and the trapezoidal surface of at least one outer core portion 32 may be exposed.

(Mounting location)
Similar to the bottom plate portion 40, the region on the installation side of the side wall portion 41 has mounting portions 411 protruding from the four corners, and each mounting portion 411 is provided with a bolt hole 411h to constitute a mounting location. ing. The bolt hole 411h may be formed only by the constituent material of the side wall portion 41, or may be formed by arranging a cylindrical body made of another material. For example, when the side wall portion 41 is formed of a resin as described later, if a metal tube made of a metal such as brass, steel, stainless steel or the like is used for the cylindrical body, since the strength is excellent, the creep deformation of the resin Can be suppressed. Here, a metal tube is arranged to form the bolt hole 411h.

(Terminal block)
In the region on the opening side of the side wall portion 41, the hook-shaped portion covering the upper side of the one outer core portion 32 functions as a terminal block 410 to which a pair of terminal fittings 8 to be described later are fixed. First, the terminal fitting 8 will be described.

[Terminal bracket]
The terminal fitting 8 will be described with reference to FIG. Each terminal fitting 8 to which each end 2e of the winding 2w constituting the coil 2 is connected is a conductive member formed by appropriately bending a plate made of a conductive material such as copper, copper alloy, aluminum, aluminum alloy. It is. An end 2e of the winding is joined to one end side of each terminal fitting 8 by welding or soldering, and an external device such as a power source is connected to the other end side to enable power supply to the coil 2.

  On one end side of each terminal fitting 8, a pair of joining pieces 81a and 81b sandwiching the end portion 2e of the winding are provided. Here, a part of the plate material is formed to be bent in a U shape, and each joining piece 81a, 81b is a rectangular piece that is connected via a curved portion and arranged in parallel. In this embodiment, after the winding end 2e is inserted between the joint pieces 81a and 81b, the conductor portion of the winding end 2e and the joint pieces 81a and 81b of the terminal fitting 8 are welded by TIG welding. , Soldering, crimping, etc. to make electrical connection.

  On the other end side of each terminal fitting 8, there is provided a through hole 82h through which a connecting member such as a bolt for connecting to an external device such as a power source is inserted. In this embodiment, in a state where the terminal fitting 8 is fixed to the side wall portion 41, the other end side region having the through hole 82h is disposed so as to protrude from the side wall portion 41 (see FIG. 1). In addition, the other end side region having the through hole 82h can also be supported by the constituent material of the side wall portion 41. For example, when the side wall portion 41 is formed of an insulating resin material as will be described later, a support base (not shown) in the other end side region may be integrally formed of the material. By appropriately arranging a nut or the like on the support base and arranging the through hole 82h coaxially with the hole of the nut, an external device can be connected through the connecting member such as the bolt.

  After each terminal fitting 8 is placed on the terminal block 410, the terminal fixing member 9 is covered from above, and the terminal fixing member 9 is fastened by a bolt 91 to be fixed to the terminal block 410. As a constituent material of the terminal fixing member 9, an insulating resin material that is used as a constituent material of a case described later can be suitably used. Further, when the side wall portion 41 is formed of an insulating resin material as will be described later, instead of using the terminal fixing member 9 and the bolt 91, the terminal fitting 8 is formed integrally with the side wall portion 41 by injection molding or the like. It is also possible.

(Case material)
As a constituent material of the case 4, for example, a metal material can be used. Since metal materials generally have high thermal conductivity, a case with excellent heat dissipation can be obtained. Specific metal materials include, for example, aluminum and its alloys, magnesium (thermal conductivity: 156 W / m · K) and its alloys, copper (398 W / m · K) and its alloys, and silver (427 W / m · K). ) And its alloys, iron, and austenitic stainless steel (eg, SUS304: 16.7 W / m · K). When the aluminum, magnesium, or an alloy thereof is used, a lightweight case can be obtained, which can contribute to weight reduction. In particular, aluminum and its alloys are excellent in corrosion resistance and are therefore suitable for use in in-vehicle parts. When the case 4 is formed of a metal material, it can be formed by plastic working such as press working in addition to casting such as die casting.

  Alternatively, as the constituent material of the case 4, for example, an insulating resin material such as polybutylene terephthalate (PBT) resin, urethane resin, polyphenylene sulfide (PPS) resin, or acrylonitrile-butadiene-styrene (ABS) resin can be used. . Since such an insulating resin material has electrical insulation, the insulation between the coil 2 and the case 4 can be enhanced. Moreover, such an insulating resin material is lighter than the metal material and contributes to further weight reduction. When the insulating resin material is mixed with a ceramic filler as will be described later, heat dissipation can be improved. When the case 4 is formed of an insulating resin material, it can be formed by injection molding.

  The constituent materials of the bottom plate portion 40 and the side wall portion 41 can be the same type of material, and in this case, the thermal conductivity of both is equal. Alternatively, since the bottom plate portion 40 and the side wall portion 41 are separate members, both constituent materials can be different materials. In this case, in particular, when both constituent materials are selected so that the thermal conductivity of the bottom plate portion 40 is larger than the thermal conductivity of the side wall portion 41, the heat of the coil 2 and the magnetic core 3 disposed on the bottom plate portion 40 is selected. Can efficiently dissipate heat to the installation target such as a cooling base. Here, the bottom plate portion 40 is formed of aluminum, and the side wall portion 41 is formed of PBT resin. In the case where the bottom plate portion 40 has electrical conductivity, an insulating property can be improved by performing anodizing or the like to provide an extremely thin insulating coating (thickness: about 1 μm to 10 μm) on the inner surface.

(Integration method)
In order to integrate the bottom plate portion 40 and the side wall portion 41, various fixing materials can be used, and examples thereof include fastening members such as adhesives and bolts. Here, bolt holes (not shown) are provided in the bottom plate part 40 and the side wall part 41, and the bolts (not shown) are used as the fixing material, and both are integrated by bolts.

[Positioning groove]
The positioning groove 45 is formed on the inner surface of the bottom plate portion 40, and positions the coil 2 here. Specifically, as described above, the bottom plate portion 40 is an aluminum metal plate, and the positioning groove 45 is formed by pressing. As shown in FIG. 4, the positioning groove 45 is formed by being pressed from the surface opposite to the inner surface of the bottom plate portion 40, and the shape thereof is the axis of the coil 2 (coil elements 2a and 2b). In the cross section in the direction orthogonal to the direction, the shape is along the outer peripheral surface of the coil 2 (coil elements 2a, 2b) facing the inner surface of the bottom plate portion 40. Thereby, when mounting the assembled body 10 on the bottom plate portion 40, the coil 2 (combined body 10) can be positioned accurately and easily without using a positioning jig. Further, since the positioning groove 45 has a shape along the outer peripheral surface of the coil 2, the distance between the coil 2 and the bottom plate portion 40 is shortened (the contact area is increased), so the heat of the coil 2 is transferred to the bottom plate portion 40. Can communicate efficiently. In addition, since the positioning groove 45 is formed by pressing, an improvement in productivity can be expected. The positioning groove 45 may be formed on the metal plate by pressing, or may be formed by cutting, or may be formed by integral molding if the bottom plate portion 40 is a die-cast product.

  Here, a metal plate in which positioning grooves 45 are formed by press working is used for the bottom plate portion 40. In this case, the thickness t of the bottom plate portion 40 (excluding the uneven portion forming the positioning groove 45) is, for example, 1 mm or more and 5 mm or less, preferably 2 mm or more, and the height of the positioning groove is 10 times the thickness t of the bottom plate portion 40. % Or more and 100% or less, preferably 50% or more. In this example, the height of the positioning groove 45 formed between the surfaces where the two coil elements 2a, 2b face each other is set to 100% of the thickness t of the bottom plate portion 40, and the two coil elements 2a, 2b face each other. The height of the positioning groove 45 formed on the side opposite to the surface is set to 50% of the thickness t of the bottom plate portion 40. In this example, the thickness of the bottom plate portion 40 is 2 mm or more, and the height of the positioning groove 45 is 1 mm or more and 4.5 mm or less. If the height of the positioning groove 45 is 1 mm or more, it is easy to prevent disappearance of the positioning groove 45 due to formation of a bonding layer 42 described later.

  In this embodiment, the positioning groove 45 for positioning only the coil 2 has been described. However, a positioning groove for positioning the magnetic core 3 may be formed. In this case, for example, a positioning groove in contact with the surface opposite to the inner end surface 32e of the outer core portion 32 may be formed so as to correspond to the core installation surface of the outer core portion 32. Thereby, the axial positioning of the coil 2 of the combined body 10 can be performed more reliably.

[Joint layer]
The bottom plate portion 40 includes a bonding layer 42 at least at a location where the coil installation surface of the coil 2 contacts. Here, the bonding layer 42 has such a size that the core mounting surface of the outer core portion 32 can also contact. This bonding layer 42 has a multilayer structure including an adhesive layer made of an insulating material on the side where the coil installation surface and the core installation surface are in contact, and a heat dissipation layer made of a material having excellent thermal conductivity on the side in contact with the bottom plate portion 40. Preferably there is.

  The adhesive layer can be formed of, for example, an insulating adhesive. Specific examples include epoxy adhesives and acrylic adhesives. Here, the adhesive layer has a single-layer structure of an insulating adhesive, and is crushed and stretched when fixing the coil 2 or the magnetic core 3 (outer core portion 32).

  On the other hand, the heat dissipation layer is formed of a material having a thermal conductivity of more than 2 W / m · K. The higher the thermal conductivity of the heat dissipation layer, the better, and it should be made of 3W / m · K or more, more than 10W / m · K, especially 20W / m · K or more, especially 30W / m · K or more. Is preferred.

As a specific constituent material of the heat dissipation layer, for example, a metal material can be cited. Since metal materials generally have high thermal conductivity but have electrical conductivity, it is desirable to improve the insulating properties of the adhesive layer. Moreover, the heat dissipation layer made of a metal material tends to be heavy. On the other hand, non-metallic inorganic materials such as ceramics, such as a material selected from metal elements, B and Si oxides, carbides, and nitrides, are excellent in heat dissipation as a constituent material of the heat dissipation layer. Moreover, it is preferable because it is excellent in electrical insulation. More specific ceramics are silicon nitride (Si ₃ N ₄ ): about 20 W / m · K to 150 W / m · K, alumina (Al ₂ O ₃ ): about 20 W / m · K to about 30 W / m · K, Aluminum nitride (AlN): about 200W / m · K to 250W / m · K, boron nitride (BN): about 50W / m · K to 65W / m · K, silicon carbide (SiC): 50W / m · K to 130W / m · K and so on. When the heat dissipation layer is formed from the ceramics, for example, a vapor deposition method such as a PVD method or a CVD method can be used. Alternatively, it is also possible to form the heat dissipation layer by preparing a sintered ceramic plate or the like and bonding it to the bottom plate portion 40 with an appropriate adhesive.

  Or the insulating resin containing the filler which consists of said ceramics can be utilized for the constituent material of a thermal radiation layer. Examples of the insulating resin include an epoxy resin and an acrylic resin. By containing the filler having excellent heat dissipation and electrical insulation in the insulating resin, a heat dissipation layer having excellent heat dissipation and electrical insulation can be obtained. Even when a resin containing a filler is used, the heat dissipation layer can be easily formed by applying the resin to the bottom plate portion 40. When the heat dissipation layer is made of an insulating resin, in particular, when an adhesive is used, the adhesion between the heat dissipation layer and the adhesive layer is excellent, so the bonding layer including the heat dissipation layer is formed between the coil 2 and the bottom plate portion 40. It is possible to firmly join the gaps. In the case of forming the heat dissipation layer from the insulating resin, for example, it can be easily formed by using screen printing. Screen printing can also be used for the above-described adhesive layer.

  Here, the heat radiation layer is formed of an epoxy adhesive containing a filler made of alumina (thermal conductivity: 3 W / m · K). The heat dissipation layer has a two-layer structure made of the above adhesive, and the thickness per layer is 0.2 mm (total 0.4 mm) (total thickness with the adhesive layer is 0.5 mm). The heat dissipation layer may be three or more layers. In the case of such a multilayer structure, at least one layer of materials may be different. For example, the heat dissipation layer can have a multilayer structure made of materials having different thermal conductivities.

  The shape of the bonding layer 42 is not particularly limited as long as it has at least an area where the coil installation surface can sufficiently contact. Here, the bonding layer 42 has a shape corresponding to the coil installation surface of the coil 2 and the core installation surface of the outer core portion 32 as shown in FIG. Therefore, both the coil installation surface and the core installation surface can be sufficiently brought into contact with the bonding layer 42.

[Sealing resin]
The case 4 may be filled with a sealing resin (not shown) made of an insulating resin. In this case, the winding end 2e is pulled out from the opening of the case 4 and exposed from the sealing resin, and the winding end 2e and the terminal fitting 8 are joined by welding or soldering. To be able to. Alternatively, depending on the shape of the side wall 41, after joining by the above-described welding or the like, a sealing resin may be filled so as to embed the winding end 2e and the terminal fitting 8.

  For example, an epoxy resin, a urethane resin, a silicone resin, or the like can be used as the sealing resin. Further, a sealing resin containing a filler having excellent electrical insulation and thermal conductivity, for example, a filler made of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, mullite, and silicon carbide; Then, heat dissipation can be further improved.

  When the case 4 is filled with the sealing resin, the packing 6 may be disposed in order to prevent uncured resin from leaking through the gap between the bottom plate portion 40 and the side wall portion 41. Here, the packing 6 is an annular body having a size that can be fitted to the outer periphery of the combined body 10 of the coil 2 and the magnetic core 3, and is made of synthetic rubber. Material can be used. On the installation surface side of the side wall 41 of the case 4, a packing groove (not shown) in which the packing 6 is disposed is formed.

<Manufacture of reactors>
Reactor 1 having the above configuration is typically prepared for assembly, side wall, bottom plate, ⇒ mounting and fixing the assembly ⇒ side wall layout ⇒ case assembly ⇒ terminal fitting and winding It can be manufactured by a process of joining with a wire and filling with a sealing resin.

[Preparation of union]
First, a procedure for producing the combination 10 of the coil 2 and the magnetic core 3 will be described. Specifically, as shown in FIG. 3, the core piece 31m and the gap material 31g are laminated to form the inner core portion 31, and the peripheral wall portion 51 (divided pieces 511, 512) of the insulator 5 is arranged on the outer periphery. The coil elements 2a and 2b are inserted. Since the peripheral wall portion 51 has a cross-sectional shape, it is easy to dispose the peripheral wall portion 51 on the surface on the installation side of the inner core portion 31 and its opposing surface. The frame-shaped portion 52 and the outer core portion 32 are arranged so that the end surfaces of both the coil elements 2a and 2b and the end surface 31e of the inner core portion 31 are sandwiched between the frame-shaped portion 52 of the insulator 5 and the inner end surface 32e of the outer core portion 32. Thus, the combined body 10 is produced. At this time, the end surface 31e of the inner core portion 31 is exposed from the opening of the frame-shaped portion 52 and contacts the inner end surface 32e of the outer core portion 32. In producing the combined body 10, the cylindrical portion of the frame-like portion 52 can be used as a guide.

  The pair of split pieces 511 and 512 constituting the peripheral wall portion 51 are not configured to engage with each other, but are inserted into the coil elements 2a and 2b together with the inner core portion 31 and the outer core portion 32 is further disposed, so that the coil The state of being arranged between the inner peripheral surfaces of the elements 2a and 2b and the outer peripheral surface of the inner core portion 31 is maintained, and there is no displacement or dropping.

[Preparation of side wall]
After the side wall portion 41 is formed of PBT resin, which is an insulating resin material, into a predetermined shape by injection molding or the like, the terminal fitting 8 is fixed to the terminal block 410 of the side wall portion 41 by the terminal fixing member 9 and the bolt 91, A side wall 41 to which the terminal fitting 8 is fixed is prepared. As described above, a terminal metal piece 8 integrally formed with the side wall portion 41 may be prepared.

[Preparation of bottom plate part, mounting / fixing of union]
As shown in FIG. 2, after a metal plate made of aluminum is punched into a predetermined shape, a positioning groove 45 is formed on one surface of the metal plate, and a bottom plate portion 40 having this surface as an inner surface is prepared. Further, a multi-layered bonding layer 42 including a bonding layer on the inner surface is formed into a predetermined shape by screen printing. Then, the produced combined body 10 is placed on the bonding layer 42 of the bottom plate portion 40, and then the bonding layer 42 is cured to fix the combined body 10 to the bottom plate portion 40. A positioning groove 45 is formed on the inner surface of the bottom plate portion 40, and this can be used for positioning of the coil 2, so that the positioning of the coil 2 with respect to the bottom plate portion 40, and hence the positioning of the assembly 10 can be performed accurately and easily. It can be carried out.

  In addition, the bonding layer 42 allows the coil 2 to be in close contact with the bottom plate portion 40, and the positions of the coil 2 and the outer core portion 32 are fixed. As a result, the inner core portion 31 sandwiched between the pair of outer core portions 32 is also positioned. Is fixed. That is, the magnetic core 3 including the inner core portion 31 and the outer core portion 32 is integrated by the bonding layer 42 without using an adhesive separately for bonding the core piece 31m and the gap member 31g. Further, by using an adhesive for the bonding layer 42, the assembly 10 is firmly fixed to the bonding layer 42.

  The bonding layer 42 may be formed immediately before the assembly 10 is placed, but the bonding layer 42 may be formed in advance. In the latter case, it is preferable to attach a release paper so that foreign matter or the like does not adhere to the bonding layer 42 until the combination 10 is placed. Only the heat dissipation layer may be formed in advance, and only the adhesive layer may be formed immediately before the assembly 10 is placed.

  In producing the combined body 10, an adhesive can be used for joining the core piece 31m and the gap material 31g. In this case, for example, after laminating the core piece 31m coated with an adhesive and the gap material 31g and assembling the inner core portion 31, the peripheral wall portion 51 of the insulator 5 and the coil 2 are disposed as described above. Then, as described above, the frame-shaped portion 52 of the insulator 5 is disposed between the coil 2 and the outer core portion 32, and the end surface 31e of the inner core portion 31 and the inner end surface 32e of the outer core portion 32 to which an adhesive is applied. Are brought into contact with each other to cure the adhesive, and the combined body 10 is produced. This configuration facilitates handling of the inner core portion 31 and the combined body 10. By bringing such a combined body 10 into contact with the bonding layer 42, the combined body 10 (particularly the coil 2) is firmly attached to the bonding layer 42 as in the case where no adhesive is used for bonding the core piece 31m and the gap material 31g. Can be fixed.

[Arrangement of side wall]
The side wall portion 41 to which the terminal fitting 8 is fixed is placed on the bottom plate portion 40 from above the combination body 10 so as to surround the outer peripheral surface of the combination body 10. At this time, the side wall portion 41 is arranged so that the end portion 2e of the winding is inserted between the joint pieces 81a and 81b of the terminal fitting 8.

[Assembly of the case]
The bottom plate portion 40 and the side wall portion 41 are integrated with a separately prepared bolt (not shown) in a state where the end portion 2e of the winding is interposed between both the joining pieces 81a and 81b. At this time, by adjusting the position of the side wall 41, the positions of the joining pieces 81a and 81 can also be adjusted.

  As described above, when the side wall 41 is covered from the upper side of the combined body 10, both the outer sides of the combined body 10 are caused by the above-described two hook-shaped portions of the side wall 41 (one hook-shaped portion becomes the terminal block 410). The trapezoidal surface above the core portion 32 is covered and stops. That is, the hook-shaped portion functions as positioning of the side wall portion 41 with respect to the combined body 10. In addition, the hook-shaped portion prevents the combined body 10 from falling off from the side wall portion 41 when the reactor 1 is installed on the installation target so that the bottom plate portion 40 is upward or sideward. A position fixing portion for preventing the outer core portion 32 from falling off may be separately provided on the inner side of the hook-shaped portion.

  Through the above steps, the box-shaped case 4 as shown in FIG. 1 is assembled, and the combined body 10 can be stored in the case 4. In addition, the winding end 2e can be interposed between the joint pieces 81a and 81b of the terminal fitting 8.

[Junction of terminal fitting and winding]
The end portion 2e of the winding and at least one of the joining pieces 81a and 81b of the terminal fitting 8 are joined by welding or soldering, and the two are electrically connected. In this example, the end portion 2e of the winding is interposed between the pair of joining pieces 81a and 81b and is maintained in contact with at least one of the joining pieces 81a and 81b. Therefore, in this joining, a jig for bringing the joining pieces 81a and 81b into contact with the winding end 2e is unnecessary. Alternatively, by filling solder between the joining pieces 81a and 81b and the end portion 2e of the winding, the two can be electrically connected via the solder. Therefore, the jig is not required for this connection. Through this step, the reactor 1 in which the case 4 is not filled with the sealing resin is manufactured.

[Filling with sealing resin]
On the other hand, the case 4 may be filled with a sealing resin (not shown). By filling the case 4 with the sealing resin and curing it, the reactor 1 including the sealing resin is manufactured. In this embodiment, the joining pieces 81a and 81b and the winding end 2e may be joined after the sealing resin is filled.

<Application>
Reactor 1 having the above-described configuration has applications where current-carrying conditions are, for example, maximum current (direct current): about 100 A to 1000 A, average voltage: about 100 V to 1000 V, operating frequency: about 5 kHz to 100 kHz, typically a hybrid It can be suitably used as a component part of an in-vehicle power converter such as an automobile or an electric vehicle.

"effect"
Reactor 1 having the above-described configuration is a structure in which case 4 is divided into bottom plate portion 40 and side wall portion 41, so that the assembly can be placed on the bottom plate portion with the side wall portion removed. Thus, it is not necessary to lift the heavy assembly to the opening of the case, and the assembly workability can be improved. Further, in the reactor 1, since the positioning groove 45 is formed on the inner surface of the bottom plate portion 40, when the combination is placed on the bottom plate portion, positioning of the combination can be performed accurately and without a positioning jig. Since it can be performed easily, the assembly workability can be further improved. Further, the positioning groove 45 has a shape along the outer peripheral surface of the coil 2 facing the inner surface of the bottom plate portion 40 in a cross section in a direction orthogonal to the axial direction of the coil 2. Therefore, not only the positioning of the coil 2 (combined body 10) with respect to the bottom plate portion 40 is facilitated, but also the distance between the coil 2 and the bottom plate portion 40 is shortened, so that the heat of the coil 2 is efficiently transmitted to the bottom plate portion 40. be able to. Therefore, the heat of the coil 2 can be efficiently radiated to the installation target such as the cooling base via the bottom plate portion 40, and the heat dissipation is excellent.

  In the reactor 1, since the bottom plate portion 40 is formed of a metal material having excellent heat conductivity such as aluminum, the heat of the coil 2 can be efficiently radiated to the installation target, and the heat dissipation is excellent. Here, the bonding layer 42 is formed on the inner surface of the bottom plate portion 40, and at least the side of the bonding layer 42 that contacts the coil 2 is formed of an insulating material, so the thickness of the bonding layer 42 is about 0.1 mm, for example. Even if it is very thin, insulation between the coil 2 and the bottom plate portion 40 can be secured. In particular, the bonding layer 42 includes a heat dissipation layer with excellent thermal conductivity, such as a thermal conductivity of more than 2 W / m · K. Therefore, the heat of the coil 2 and the magnetic core 3 constituting the assembly 10 is transmitted through the heat dissipation layer. Since heat can be efficiently transmitted to the bottom plate portion 40 and efficiently radiated to the installation target, heat dissipation is improved. In this example, since all the layers constituting the bonding layer 42 are formed of an insulating material, sufficient insulation between the coil 2 and the bottom plate portion 40 can be achieved. In addition, since the bonding layer 42 is thin, heat from the coil 2 and the like can be easily transmitted to the bottom plate portion 40 and can be efficiently radiated to the installation target via the bottom plate portion 40, so that heat dissipation is improved. Further, since the bonding layer 42 is thin, the distance between the coil installation surface of the coil 2 and the inner surface of the bottom plate portion 40 can be reduced, and downsizing can be realized. Furthermore, since all the layers constituting the bonding layer 42 are formed of an insulating adhesive, the adhesion between the coil 2 and the magnetic core 3 and the bonding layer 42 is excellent. Easy to convey to 42, improving heat dissipation. In addition, since a coated rectangular wire is used for the winding 2w, the entire side surface portion of each turn constituting the coil installation surface can be brought into contact with the bonding layer 42, and the coil 2 and the bonding layer can be contacted. Since the contact area with 42 is large, heat dissipation is improved. Since the operation of forming the bonding layer 42 can be performed with the side wall portion 41 removed, it is easy to improve the assembly workability.

  Here, since the bottom plate portion 40 is a metal plate such as aluminum in which the positioning groove 45 is formed by press working, the bottom plate portion 40 can be easily manufactured, and cost reduction and productivity improvement can be achieved.

  On the other hand, since the side wall portion 41 is formed of an insulating resin material such as PBT resin, the inner surface of the side wall portion 41 can be disposed close to the outer peripheral surface of the coil 2, thereby achieving downsizing. be able to. Further, since the resin material is lighter than the metal material, the weight can be reduced.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration. For example, the shape, location, number, etc. of the positioning groove can be changed as appropriate.

  The reactor of this invention can be utilized suitably for the components of power converters, such as a vehicle-mounted converter mounted in vehicles, such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle. The reactor case of the present invention can be suitably used for the reactor of the present invention.

1 Reactor 10 Union
2 coils
2a, 2b Coil element 2r Coil connection part 2w Winding
2e Winding end (feeding point)
3 Magnetic core
31 Inner core 31e End face 31m Core piece 31g Gap material
32 Outer core part 32e Inner end face
4 cases
40 Bottom plate part 41 Side wall part 42 Bonding layer 45 Positioning groove
400,411 Mounting part 400h, 411h Bolt hole 410 Terminal block
5 Insulator
51 Peripheral walls 511,512 Split pieces
52 Frame 52p Pedestal
6 Packing
8 Terminal bracket
81a, 81b Joint piece 82h Through hole
9 Terminal fixing member 91 bolt

Claims (7)

A reactor comprising a combined body having a coil formed by winding a winding and a magnetic core on which the coil is disposed, and a case storing the combined body,
The case is
A bottom plate portion that contacts the installation target when the reactor is installed on the installation target;
It is independent of the bottom plate part, and is integrated with the bottom plate part by a fixing material, and includes a side wall part surrounding the combination,
A reactor having a positioning groove for positioning at least one of the coil and the magnetic core is formed on an inner surface of the bottom plate portion. The combination is housed in the case so that the axial direction of the coil is parallel to the inner surface of the bottom plate portion,
The reactor according to claim 1, wherein the positioning groove has a shape along an outer peripheral surface of the coil facing an inner surface of the bottom plate portion in a cross section in a direction orthogonal to the axial direction of the coil.   The reactor according to claim 1, wherein the bottom plate portion is a metal plate in which the positioning groove is formed by press working.   The reactor according to any one of claims 1 to 3, wherein the side wall portion is formed of an insulating resin material. A bonding layer for fixing the coil to the inner surface of the bottom plate portion;
The bonding layer is disposed on the side in contact with the coil, has an adhesive layer made of an insulating adhesive, and a heat dissipation layer disposed on the side in contact with the bottom plate part,
The total thickness of the said joining layer is less than 2 mm, The reactor as described in any one of Claims 1-4 characterized by the above-mentioned.   The reactor according to claim 5, wherein at least a part of the heat dissipation layer is made of a material having a thermal conductivity of more than 2 W / m · K. A reactor case that houses a combined body having a coil formed by winding a winding and a magnetic core on which the coil is disposed,
A bottom plate portion that contacts the installation target when the reactor is installed on the installation target;
It is independent of the bottom plate part, and is integrated with the bottom plate part by a fixing material, and includes a side wall part surrounding the combination,
A reactor case, wherein a positioning groove for positioning at least one of the coil and the magnetic core is formed on an inner surface of the bottom plate portion.

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