JP5246502B2 - Reactor and converter - Google Patents

Description

  The present invention relates to a reactor used for circuit components that perform voltage step-up and step-down operations. In particular, the present invention relates to a reactor that is small and excellent in heat dissipation.

  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 Documents 1 and 2 disclose a reactor used for circuit components of a converter mounted on a vehicle such as a hybrid vehicle. The reactor includes an annular magnetic core, a coil having a pair of coil elements arranged side by side on the outer periphery of the core, and a case for housing a combination of the magnetic core and the coil. The case is typically made of aluminum (paragraph 0037 of Patent Document 2). The above assembly is sealed with a potting resin filled in the case (FIG. 3 of Patent Document 2), and this case has screws and bolts so that the coil and the magnetic core that generate heat when energized can be efficiently cooled. It is fixed to the cooling base using, for example, and used for the heat dissipation path. A cylindrical bobbin made of an insulating resin is disposed on the outer periphery of the magnetic core (FIG. 8 of Patent Document 2) to insulate between the magnetic core and the coil.

JP 2006-351675 A JP 2007-116066

  In particular, it is desired that parts mounted on vehicles such as automobiles be small and light. However, it is difficult to further reduce the size and weight of a reactor including a case as described above.

  It is conceivable to omit the case in order to reduce the size and weight. However, in this case, there is a concern about a decrease in heat dissipation. Further, when the case is omitted, there is a possibility that the mutual positioning of the magnetic core and the coil becomes difficult, or a deviation occurs after the combination.

  Then, one of the objectives of this invention is providing the reactor which is excellent in heat dissipation, although it is small. Another object of the present invention is to provide a reactor that can easily position a coil and is excellent in assembly workability.

  Instead of omitting the entire case, it is conceivable to use a pedestal in which only a part of the case, for example, the side wall is omitted. However, if the pedestal is a flat, flat plate, the contact area between the combination of the magnetic core and the coil and the pedestal is small, so that the effect of improving heat dissipation is small. Further, in the pedestal as described above, it is difficult to position the assembly on the pedestal, and the assembly workability of the reactor is also inferior. Then, the structure which performs positioning by providing the dent along the outer periphery shape of the said assembly in a base, and fitting the said assembly in this recess was examined. However, in the configuration in which only one relatively large dent is formed on the flat plate, it has been found that the pedestal may be warped. When warping occurs in the pedestal, the pedestal becomes difficult to adhere to the cooling base, resulting in a decrease in heat dissipation. Further, as described above, the mechanical strength of the pedestal is lowered in the configuration in which only one relatively large recess is formed.

  Therefore, in the present invention, in addition to providing a recess for fitting the assembly into the pedestal, the pedestal is shaped so as not to warp.

  The present invention is a reactor including an annular magnetic core and a coil disposed on the outer periphery of the magnetic core, and includes a heat radiating table on which a combination of the magnetic core and the coil is disposed. In this heat radiating stand, at least the surface on the side where the above-mentioned combination is arranged is made of an insulating material. Moreover, this heat sink has a recessed part in which a part of said combination is fitted. This recessed part has a partition part which partitions off the internal space of the said recessed part into several small space. And both the end surfaces and the outer side surfaces of the coil are positioned by fitting a part of the coil into a small space of the concave portion partitioned by the partition portion.

  The reactor of the present invention does not include a case composed of a pedestal and a side wall standing upright from the pedestal, and includes a heat radiating base composed of only a pedestal portion that does not have a side wall. Excellent heat dissipation. In particular, this heat sink has a recess into which a part of the assembly is fitted, so that the contact area between the assembly and the recess (not only in the case of direct contact but also through inclusions (including fine gaps)). And indirect contact) can be increased. For this reason, the heat of the combined body can be efficiently transmitted to the heat radiating stand from the portion of the combined body that is fitted in the recessed portion and surrounded by the recessed portion, and is excellent in heat dissipation. In addition, since the both ends and the outer surface of the coil can be easily positioned by fitting the combination into the recess, the reactor of the present invention is excellent in assembling workability, and the combination is provided by the heat radiating stand. It is excellent in handling properties by being integrated. In addition, since the both end faces and the outer face of the coil are positioned, the positions are hardly displaced even after assembly. Furthermore, the coil can be held in a compressed state by positioning both end faces of the coil. And since the said recessed part is divided | segmented into the some small space by the partition part, the curvature of a heat sink can be suppressed compared with the case where one big dent is provided. Therefore, it is easy to make a heat sink stand closely to fixed objects, such as a cooling base, and also from this point, this invention reactor is excellent in heat dissipation. Moreover, the mechanical strength of a heat sink can also be raised by providing the said partition part. Hereinafter, a more specific configuration of the reactor of the present invention will be described.

  Examples of the magnetic core provided in the reactor of the present invention include a coil winding portion in which the coil is disposed and an exposed portion in which the coil is not disposed. In particular, a shape in which the surface of the exposed portion on the side of the heat sink is protruded from the surface of the coil winding portion on the side of the heat sink. In the case where the magnetic core has such a shape, the recess of the heat radiating stand has a combination partition part interposed between the exposed part of the magnetic core and the end face of the coil as the partition part. It is done. Further, as the small space provided in the concave portion, a coil concave portion for positioning the coil by fitting the coil, and a core for positioning the magnetic core by fitting a protruding portion in the exposed portion of the magnetic core. The form which has a recessed part is mentioned.

  In the configuration including the coil recess and the core recess as described above, both the coil and the magnetic core are fitted into the recess, so that the contact area with the heat radiating base is increased, and the heat dissipation is improved. Both cores can be easily positioned. In this embodiment, the combination partition is arranged so as to be orthogonal to the axial direction of the coil.

  Examples of the coil provided in the reactor of the present invention include a form having a pair of coil elements disposed on the outer periphery of the magnetic core. When a coil is such a form, the recessed part of the said heat sink has the form which has the element partition part interposed between the said coil elements as said partition part. Moreover, the said small space provided in this recessed part has the form which has a coil recessed part which each said coil element is each engage | inserted and positions the said coil element.

  According to the said structure, since the element partition part exists between the coil elements which become high temperature easily, since the heat of a coil can be transmitted to an element partition part, heat dissipation is improved. In addition, by fitting the coil elements into the respective coil recesses, both end surfaces and both outer surfaces of each coil element are positioned, and the coil elements are not easily displaced within the coil recesses.

  As the arrangement form of the two coil elements, there are a vertically arranged state in which the axial directions of the coil elements are coaxial and a horizontally arranged state in which the axial directions of the coil elements are parallel to each other. In the vertically aligned state, the element partitioning portions are arranged so as to be orthogonal to the axial direction. In the side-by-side state, the element partitioning portions are arranged to be parallel to the axial direction. When both coil elements are arranged side by side, the temperature between the coil elements is likely to be higher than in the case where the coil elements are arranged side by side. Therefore, by providing an element partition portion, heat dissipation can be improved.

  In particular, when the structure includes both the combination partition part and the element partition part, the portion to be fitted into the recess in the combination is excellent in heat dissipation and the positioning of the coil and the magnetic core is more reliable. Can be done. Moreover, in this structure, the curvature of a heat sink can be suppressed more effectively and the mechanical strength of the heat sink can be further increased. In particular, when both the coil elements are arranged side by side as described above, the presence of both the partition portion along the axial direction of the coil and the partition portion along the direction orthogonal to the axial direction of the coil makes the warping more effective. Can be suppressed.

  The small space of the concave portion, more specifically, the core concave portion and the coil concave portion may be a bottomed concave portion having a bottom portion, or may be a through hole penetrating from one surface of the heat radiating table to the other surface. The structure which has both a bottomed recessed part and a through-hole may be sufficient.

  When at least one of the small spaces is a bottomed recess, if a part of the combination fitted in the bottomed recess is in contact with the bottom, the contact area between the combination and the heat sink is increased. , Heat dissipation can be improved. Moreover, in this structure, since the combined body inserted by the bottomed recessed part does not contact a fixing object etc. directly, a combined body can be protected mechanically.

  When at least one of the small spaces is a through hole, a part of the combined body fitted in the through hole is exposed from the through hole, and the exposed portion of the combined body is flush with the one surface of the heat sink. With this configuration, the exposed portion can directly contact a fixed object such as a cooling base. Therefore, the heat of the assembly can be directly released to the fixed object. In addition, even if it is a through-hole, a heat sink has high mechanical strength by providing a partition part as mentioned above.

  The magnitude | size of the said partition part can be adjusted suitably. For example, as the size of the combination partition portion disposed between the coil and the magnetic core (typically the exposed portion), the inner peripheral surface of the coil does not contact the coil winding portion of the magnetic core, and the combination The magnitude | size which the end surface of a body partition part touches a coil winding part is mentioned. In this case, the combination partition portion is interposed between the magnetic core and the end face of the coil, so that the insulation between the magnetic core and the coil can be enhanced, and the coil inner circumference and the coil winding of the magnetic core can be increased. A gap can be generated between the two parts. It is expected that the insulation between the coil and the magnetic core can be enhanced by this gap, and the bobbin provided on the outer periphery of the conventional magnetic core can be omitted or simplified.

  The reactor of the present invention is small and lightweight, and has excellent heat dissipation.

FIG. 1 is an explanatory view for explaining the procedure for assembling the reactor of the first embodiment. FIG. 2 is a schematic front view of the reactor of the first embodiment. FIG. 3 shows a modification of the heat radiating table, FIG. 3 (A) is a cross-sectional view of the heat radiating table having a bolt hole, FIG. FIG. 3 (C) is a schematic perspective view of a heat sink having a shape along the outer shape of the combined body. FIG. 4 is a schematic perspective view showing another modified example of the heat radiating table, FIG. 4 (A) is an example having a notch in the combination partition part, and FIG. 4 (b) is a convex part in the combination partition part. An example having FIG. 5 is a schematic perspective view of another heat radiating stand, FIG. 5 (A) is a modified example of the combination partition part, and FIG. 5 (B) is an example including the combination partition part and the element partition part, FIG. 5 (C) shows an example including the combination partition section and the element partition section of the above modification. FIG. 6 (A) is a schematic front view of the reactor according to the second embodiment, and FIG. 6 (B) is a schematic perspective view of a heat radiating stand included in the reactor. FIG. 7 (A) is a schematic front view of a reactor having a fixed structure different from that of the reactor according to the first embodiment, and FIG. 7 (B) is a schematic perspective view of a heat radiating stand included in the reactor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1>
FIG. 1 is an exploded perspective view showing an outline of the reactor of the present invention, and FIG. 2 is a schematic front view of the reactor, showing a state in which a heat radiation stand is cut. Hereinafter, the same reference numerals in the drawings indicate the same names. The reactor 1 includes a combined body 10 having an annular magnetic core 11 and a coil 12 disposed on the outer periphery of the magnetic core 11, and a heat radiation base 13 on which the combined body 10 is disposed. The reactor 1 is used by fixing the radiator 13 to a fixed object 100 (FIG. 2) such as a cooling base. The feature of the reactor 1 is the shape of the heat sink 13. Hereinafter, each configuration will be described in more detail.

[Magnetic core]
The magnetic core 11 includes a pair of rectangular parallelepiped coil winding portions 11c in which the coil 12 is disposed, and a pair of rectangular parallelepiped end cores (exposed portions) 11e in which the coil 12 is not disposed, and is spaced apart. The end core 11e is disposed so as to sandwich the coil winding portion 11c to be formed, and is formed in a closed loop shape (annular shape). The magnetic core 11 is mainly made of a soft magnetic material containing iron such as iron or steel, and may include a gap material made of a nonmagnetic material such as an air gap or alumina for adjusting the inductance. Here, the coil winding portion 11c is configured by alternately laminating a core formed of a soft magnetic powder compact or a laminate of a plurality of electromagnetic steel plates and a gap material, and an end core 11e. Is composed of the core piece. The core piece, the gap material, and the core pieces are integrally joined with, for example, an adhesive. The number of core pieces divided and the presence or absence (number) of gaps can be selected as appropriate so that the reactor 1 has a desired inductance. Further, the shapes of the coil winding part 11c and the end core 11e can be selected as appropriate. For example, the coil winding part may be a columnar shape, and the end core 11e may be a U-shaped core having a curved surface as shown in FIG. When the U-shaped core having the curved surface is used, it is easy to allow magnetic flux to pass, and when the end core is a rectangular parallelepiped shape, it is easy to manufacture and the curved portion protruding outward in the U-shaped core. Since there is no, the magnetic core can be made smaller.

  As shown in FIG. 2, the magnetic core 11 is H-shaped when viewed from the front, and the outer peripheral surface of the end core 11e protrudes from the outer peripheral surface of the coil winding portion 11c. More specifically, the heat sink side (fixed target side) surface (hereinafter referred to as the mounting surface) 110e in the end core 11e is the heat sink side (fixed target side) surface (hereinafter referred to as the mounting surface) in the coil winding portion 11c. (Referred to as a mounting surface) 110c. Further, the facing surface 111e facing the mounting surface 110e of the end core 11e also protrudes from the coil winding portion 11c. In the reactor 1 shown in FIG. 2, the heat sink side (fixed target side) surface 120 (hereinafter referred to as the mounting surface) 120 of the coil 12 and the facing surface of the mounting surface 120 are the end cores of the magnetic core 11. 11e has a shape projecting from the mounting surface 110e and the opposing surface 111e, but by adjusting the size of the end core, the mounting surface and the opposing surface of the coil and the mounting surface and the opposing surface of the end core May be flush with each other.

[coil]
The coil 12 includes a pair of coil elements 12a and 12b formed by spirally winding one continuous winding. Each coil element 12a, 12b is arranged in each coil winding part 11c. Here, the winding uses a coated wire having an enamel coating on the surface of a copper flat wire, but in addition to the above flat wire, various shapes such as a circular shape and a polygonal shape are used. it can. Each of the coil elements 12a and 12b is formed by edgewise winding the covered wire. Further, the coil elements 12a and 12b are arranged side by side so that the axial directions of the coil elements 12a and 12b are parallel to each other, and are connected by a winding unit (not shown). Each coil element may be manufactured by separate windings, and ends of the windings forming each coil element may be joined by welding or the like to form an integrated coil.

  Both ends (not shown) of the windings forming the coil 12 are joined to a terminal member (not shown) made of a conductive material, and an external power source or the like that supplies power to the coil 12 through this terminal member. A device (not shown) is connected. For joining, welding such as TIG welding can be used.

[Heat sink]
The combined body 10 of the magnetic core 11 and the coil 12 is mounted on a heat radiating table 13. The radiator 13 has a rectangular flat plate shape and has a bottomed recess 14 into which a part of the combined body 10 is fitted. Here, in the concave portion 14, the internal space of the concave portion 14 is divided into three small spaces by two rectangular plate-like partition portions (combined body partition portions) 15a and 15b. One of the small spaces is a coil recess 140 into which a part of the coil 12 is fitted, and each of the remaining two small spaces is a core into which a protruding portion protruding from the coil winding portion 11c is fitted in the end core 11e. Recesses 141 and 142.

  The coil recess 140 and the core recesses 141 and 142 are both rectangular box-shaped bottomed recesses. More specifically, the coil recess 140 is composed of a bottom portion 14b, a pair of side surfaces 140s, one surface of the combination partition portion 15a and one surface of the combination partition portion 15b, and the coil elements 12a in a side-by-side state. The shape is in line with the shape of 12b and has a size that allows both coil elements 12a and 12b to be fitted. When the coil 12 is fitted into the coil recess 140, the coil mounting surface 120 is in contact with the bottom 14b as shown in FIG. 2, and both end surfaces of the coil 12 (surfaces in which the coil turns appear to be annular, left and right in FIG. Surface) is sandwiched between one surface of the combination partition portions 15a and 15b, and one outer surface of each of the coil elements 12a and 12b (the left and right surfaces in FIG. 1 where the coil elements 12a and 12b are not in contact with each other, the front surface in FIG. The surface that is visible) is sandwiched between both side surfaces 140s of the coil recess 140. In this way, a part of the coil 12 is surrounded by the coil recess 140, whereby the position of the coil 12 is defined. That is, the position of the coil 12 in the axial direction is defined by one surface of the combination partitioning portions 15a and 15b, and the position of the coils 12 in the side-by-side direction (left-right direction in FIG. 1) is defined by both side surfaces 140s of the coil recess 140. Is done.

  The core recesses 141 and 142 have the same shape, and are constituted by a bottom portion 141b (142b) (FIG. 2), a pair of side surfaces, the other surface of the assembly partition portion 15a (15b), and a surface facing this other surface. The shape is along the rectangular parallelepiped end core 11e, and is large enough to fit the end core 11e. When the end core 11e of the magnetic core 11 is fitted into the core recesses 141 and 142, the mounting surface 110e of the end core 11e is in contact with the bottom portions 141b and 142b as shown in FIG. The position of the magnetic core 11 (particularly, the end core 11e) is defined by being surrounded by the other surfaces of the combination partitioning portions 15a and 15b and the opposing surfaces thereof.

  In this reactor 1, the inner peripheral surface 12i of the coil 12 is placed on the outer peripheral surface of the coil winding portion 11c in a state where the coil 12 is fitted in the coil concave portion 140 of the heat radiation base 13 and the end core 11e is fitted in the core concave portions 141 and 142. The depths of the coil recess 140 and the core recesses 141 and 142 are adjusted so as not to contact each other. In addition, in the state where the coil 12 and the end core 11e are fitted in the recess 14 (140, 141, 142) as described above, the end surfaces 150a, 150b of the assembly partitioning portions 15a, 15b are placed on the mounting surface 110c of the coil winding portion 11c. The height t (the size in the vertical direction in FIG. 2) of the combination partitioning portions 15a and 15b is adjusted so as to come into contact.

  By adjusting the depth of the recess 14 of the heat sink 13 as described above, when the combined body 10 is fitted into the recess 14, the coil 12 is supported by the bottom 14b of the coil recess 140, and its position (height) Is maintained, and the end core 11e is supported by the bottom portions 141b and 142b of the core concave portions 141 and 142, and the position (height) is maintained, so that the inner peripheral surface 12i of the coil 12 and the outer periphery of the coil winding portion 11c are maintained. A gap is formed between the surface (particularly, the mounting surface 110c and its opposing surface). Further, the combination partition portions 15a and 15b can be interposed between the end core 11e and the end face of the coil 12 by adjusting the height t of the combination partition portions 15a and 15b as described above.

Various materials that are excellent in heat dissipation can be used as the constituent material of the heat sink. In particular, a non-magnetic material is preferable because a coil is disposed on the heat dissipation table. As such materials, organic materials (resins) such as epoxy resin, urethane resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin, steel, stainless steel, aluminum, Metallic inorganic materials such as aluminum alloy, copper, copper alloy, alumina (Al ₂ O ₃ ): about 20-30 W / m ・ K, silicon nitride (Si ₃ N ₄ ): about 20-150 W / m ・ K, aluminum nitride ( AlN): 200 to 250 W / m ・ K, Boron nitride (BN): 50 to 65 W / m ・ K, Silicon carbide (SiC): Nonmetal inorganic such as ceramics such as 50 to 130 W / m ・ K Examples include materials (numerical values are thermal conductivity), filler-filled resins obtained by mixing the above ceramic particles with the above-described resins, and the like. Resins and ceramics are lightweight, and metal materials have high heat dissipation. The heat radiation stand may be composed of one type of material selected from the above materials, or may be composed of a combination of a plurality of types of materials. When using resin, when using ceramics by insert molding or injection molding, etc. When molding and sintering to a desired shape, and then applying laser processing or grinding process appropriately, when using metal, the desired shape A heat radiation stand can be formed by casting or performing appropriate cutting after that.

  In particular, in order to improve the insulation between the heat sink and the coil, the constituent material of the surface on the side where the combination of the magnetic core and the coil is arranged at least in the heat sink is an insulating material, for example, the above resin And filler-containing resin mixed with ceramics and ceramic particles. Therefore, the heat radiating stand is made of only an insulating material, or when the metal is used, it is assumed that the metal portion is covered with the insulating material so that the metal portion does not come into contact with the coil or the like. For example, it is possible to form a heat sink having a coil recess or a core recess by molding a resin so as to cover one surface of the metal plate or by molding a resin so as to cover the entire surface of the metal plate. A metal base similar to the final shape of the radiator base may be formed by casting or cutting, and the resin may be coated to cover the surface of this base, or other sheet material made of insulating paper or insulating material May be interposed between the coil and the metal base. The greater the proportion of metal in the heat sink, the higher the heat dissipation. Here, the heat radiating table 13 is made of an epoxy resin.

  In addition, the radiator 13 has insertion holes 16 through which bolts 200 for fixing the reactor 1 to the fixing object 100 are inserted at locations where the assembly 10 is not arranged, specifically, at four corners.

[Assembly of the reactor]
The reactor 1 having the above configuration can be formed as follows.

  First, the combined body 10 of the magnetic core 11 and the coil 12 is formed. Specifically, the coil piece 11c is formed by fixing the core piece and the gap material with an adhesive or the like, and the coil elements 12a and 12b are respectively arranged on the outer periphery thereof. The coil 12 is prepared separately by winding a winding. The end core 11e is arranged on the coil 12 so that both end faces of the coil 12 are sandwiched between the end cores 11e, and the end core 11e and the coil winding part 11c are joined with an adhesive or the like, and the combined body 10 Form. Further, the heat radiating table 13 having the coil recess 140 and the core recesses 141 and 142 is prepared by injection molding or the like.

  Next, the reactor 1 is assembled by fitting the coil 12 of the formed assembly 10 into the coil recess 140 of the heat radiating base 13 and the end core 11e into the core recesses 141 and 142, respectively.

  In order to more securely fix the combined body 10 to the radiator 13, the gap between the coil 12 and the coil recess 140 or the gap between the end core 11e of the magnetic core 11 and the core recesses 141 and 142 may be filled with an adhesive. . Further, a resin coating layer may be formed so as to cover the outer periphery of the assembly of the combined body 10 and the radiator 13. By providing the resin coating layer, mechanical protection of the coil and the magnetic core can be achieved. Examples of the constituent material of the resin coating layer include resins such as an epoxy resin, a PPS resin, and a liquid crystal polymer (LCP). Alternatively, a resin containing a filler having high thermal conductivity such as ceramics may be used. In this case, thermal conductivity can be further increased. In addition, if the surface fixed to the fixing target 100 in the heat sink 13 is exposed from the resin coating layer so as to be in contact with the fixing target 100, the heat from the heat sink 13 can be efficiently released to the fixing target 100. Can do.

[Fix reactor]
The reactor 1 having the above configuration is arranged on the fixed object 100 so that one surface of the heat radiating table 13 is in contact with the fixed object 100, and the bolt 200 is inserted into the insertion hole 16 and screwed into the fixed object 100. Used fixed to.

[effect]
Since the reactor 1 includes the heat radiating stand 13, the reactor 1 is lighter and smaller than a reactor including a case, and is excellent in heat dissipation. In particular, the heat sink 13 includes a coil recess 140 into which the coil 12 is fitted and a core recess 141, 142 into which the magnetic core 11 is fitted, so that the coil 12 and the Since the heat of the magnetic core 11 can be directly transferred to the heat radiating base 13 and released, it is more excellent in heat dissipation. In addition, the reactor 1 can be positioned not only on both end surfaces of the coil 12 but also on the outer surface of the coil 12 by fitting the combined body 10 into the concave portion 14, and the magnetic core 11 can also be easily positioned. Excellent assembly workability. Further, not only the coil 12 but also the magnetic core 11 (particularly, the end core 11e) is configured to be fitted into the recess 14, so that the reactor 1 can be positioned in both the coil 12 and the magnetic core 11 after assembly. Hard to slip. Furthermore, since the both end surfaces of the coil 12 are positioned, the coil can be held in a compressed state. In addition, since the combined body 10 is integrated by the heat sink 13, the reactor 1 is excellent in handling properties and can be easily fixed.

  The reactor 1 does not have the concave portion 14 as one large concave portion, but has a plurality of bottomed concave portions partitioned by the combination partition portions 15a and 15b. Even thin plates are less likely to warp. Therefore, it is easy to make one surface of the heat radiating table 13 closely contact with the fixed object 100 such as a cooling base, and the reactor 1 is also excellent in heat dissipation from this point. In addition, the mechanical strength of the radiator 13 can be increased by providing the combination partition portions 15a and 15b.

  Furthermore, the reactor 1 has a predetermined gap between the inner peripheral surface 12i of the coil 12 and the outer peripheral surface of the coil winding portion 11c by adjusting the depth of the recess 14 and the height of the combination partitioning portions 15a and 15b. In addition to providing a gap, an insulator can be interposed between the end face of the coil 12 and the end core 11e. Accordingly, the reactor 1 can reduce the number of parts and work processes by omitting the bobbin, and can be reduced in weight by omitting the bobbin, and has excellent insulation.

  In addition, the magnetic core 11 of the reactor 1 has the same volume as the magnetic core in which the end core and the coil winding portion are flush with each other because the end core 11e protrudes from the coil winding portion 11c. Compared with this magnetic core, the axial length of the coil is shortened. Therefore, the reactor 1 has a small installation area and is small.

  The reactor 1 is configured to fix the reactor 1 to a fixed object 100 such as a cooling base so that the axial direction of the coil 12 is horizontal. With such a fixing structure, since the area where the coil 12 is in contact with the fixing object 100 via the heat radiating base 13 is increased, the heat of the coil 12 can be efficiently transmitted to the fixing object 100 and the heat dissipation is excellent. Such a fixing structure can be suitably used when the reactor is used in a circuit having a relatively large amount of current and a large amount of heat generated by the coil, such as a converter mounted on a vehicle such as a hybrid vehicle.

(Modification 1)
In the first embodiment, the heat sink 13 is made of a single material. However, a heat sink formed by using a plurality of materials, for example, a heat sink in which the surface of a metal plate is covered with a resin is used. May be.

(Modification 2)
In the first embodiment, the end faces 150a and 150b of the combination partitioning portions 15a and 15b have a height that makes contact with the coil winding portion 11c. However, the height may be such that the coil winding portion does not make contact with the coil winding portion. In the first embodiment, the bobbin is not provided on the outer periphery of the coil winding portion 11c. However, a bobbin may be provided between the magnetic core 11 and the coil 12. As the bobbin constituent material, PPS resin, polytetrafluoroethylene (PTFE) resin, LCP and the like can be used.

(Modification 3)
FIG. 3 shows a modification of the heat sink provided in the reactor of the present invention, (A) is a schematic cross-sectional view of a heat sink having a bolt hole, (B) is a cross-sectional schematic of a heat sink having a nut portion. FIG. (C) is a schematic perspective view of a heat sink having a shape along the outer shape of the combined body. 3A and 3B show only the vicinity of the bolt hole and the vicinity of the nut portion. In the first embodiment, the heat sink 13 is provided with the insertion holes 16 through which the bolts 200 are inserted.However, like the heat sink 13A shown in FIG. It may be. Further, as in the heat dissipating table 13B shown in FIG. 3 (B), a configuration may be provided that includes a nut 210 disposed coaxially with the through hole 16B together with the through hole 16B. The nut 210 can be fixed by a resin or the like that constitutes the heat radiating table 13B. The heat sink 13A, 13B can be fixed to the fixing object 100 by providing a through hole or a bolt hole in the fixing object 100 and screwing in the bolt 200. Alternatively, it is shaped like the heat sink 13C shown in FIG. 3 (C) along the outer shape of the combined body, and a hole is formed or inserted into the hole (in the heat sink 13 of the reactor 1 of the first embodiment). The four corners may be omitted. The radiator 13C is formed to be relatively thick, and in FIG. 3C, a bolt hole (not shown) as shown in FIG. 3A is provided on the lower surface of the radiator 13C. Since the location where the bolt hole is formed overlaps with the location where the coil recess 140 and the core recesses 141 and 142 are formed, the radiator 13C has a smaller mounting area and is smaller than the radiator 13 of the first embodiment. These heat radiation stands 13A, 13B, and 13C can be suitably used particularly when the object to be fixed 100 is relatively thin such as a circuit board and it is difficult to perform screwing.

(Modification 4)
In Embodiment 1 described above, the coil recess 140 and the core recesses 141 and 142 are both bottomed recesses, but the coil recess is a through-hole extending from one surface of the heat sink to the other surface, and the thickness of the heat sink is adjusted. The mounting surface 120 of the coil 12 may be exposed from the through hole and may be in contact with the fixed object 100 such as a cooling base. Further, when the placement surface of the end core and the placement surface of the coil are flush with each other, both the coil recess and the core recess may be through holes. In this configuration, since the mounting surface of the coil and the mounting surface of the magnetic core exposed from the through hole can be directly brought into contact with the cooling base, the heat of the coil and the magnetic core can be efficiently transmitted to the cooling base. . Moreover, even if it uses a coil recessed part and a core recessed part as a through-hole, a heat sink can be reinforced by the combination partition part existing.

(Modification 5)
In Embodiment 1 described above, the combination partition portions 15a and 15b have been described as being composed of a single rectangular plate-like member, but a plurality of members are spaced apart as a single assembly partition portion. It is good also as a form. Each member can have any shape such as a round bar shape or a square bar shape. Further, in the first embodiment, the configuration in which the size of the surface facing the end core 11e in the combination partitioning portions 15a and 15b is substantially equal to the size of the end core 11e has been described. The size can be appropriately selected. For example, in the heat sink, one protrusion smaller than the length in the side-by-side direction of the coil in the end core (hereinafter referred to as the length of the end core) is interposed between the end core and the end face of the coil. It is good also as providing the said protrusion and making this protrusion into an assembly partition part.

(Modification 6)
FIG. 4 shows a modified example of the heat radiating stand provided in the reactor of the present invention, (A) shows an example in which a cutout is provided in the combination partition, and (B) shows a protrusion in the combination partition. This is an example. Here, only the heat radiating stand will be described, and the other configuration is the same as that of the first embodiment, and thus the description thereof will be omitted. In the first embodiment, the configuration has been described in which the core recesses 141 and 142 are provided in the heat sink 13 so that the end core 11e of the magnetic core 11 can be particularly positioned. As in the heat dissipating table 13D shown in FIG. 4 (A), the combination partitioning portions 15a and 15b may be provided with a notch 155 into which the coil winding portion of the magnetic core is fitted. By fitting the coil winding portion into the notch 155, the coil winding portion can be positioned in the horizontal direction. Also, by adjusting the horizontal formation position of the notch 155 along with the horizontal length of the coil recess 140, the inner peripheral surface of the coil and the outer peripheral surface of the coil winding portion (particularly, the mounting surface and its opposing surface) A predetermined gap can be provided between the two surfaces. Further, as described in the first embodiment, by adjusting the depths of the coil recess 140 and the core recesses 141 and 142, a gap can be provided between the inner peripheral surface of the coil and the entire outer periphery of the coil winding portion. . Therefore, by providing the heat radiating table 13D, the insulation is excellent even if the bobbin is omitted.

  Like the heat sink 13E shown in FIG. 4 (B), instead of the notch 155, the end faces 150a, 150b of the assembly partitioning portions 15a, 15b are provided with a plurality of convex portions 156, and the magnetic cores are formed between the convex portions 156. Even in the configuration in which the coil winding part is fitted, the coil winding part can be positioned in the horizontal direction in the same manner as the heat radiation table 13D.

  The modifications 1 to 6 can be applied as appropriate to the embodiments and modifications described later.

<Embodiment 2>
FIG. 5 is a schematic perspective view showing another heat radiating stand provided in the reactor of the present invention, FIG. 5 (A) is an example including a combination partition part longer than Embodiment 1, and FIG. FIG. 5 (C) shows an example including the long combination partition part and the element partition part. Here, only the heat radiating stand will be described, and the other configuration is the same as that of the first embodiment, and thus the description thereof will be omitted.

(Heat sink 13α)
In the first embodiment, the configuration has been described in which the shape of the core recesses 141 and 142 included in the heat radiation base 13 is along the outer shape of the end core 11e of the magnetic core 11. Like the heat sink 13α shown in FIG. 5A, the core recesses 141α and 142α do not have to follow the outer shape of the end core. The core recesses 141α and 142α of the heat radiating base 13α have a size along one end along the length of the end core, and the other side facing this one side, that is, the end core side of the combination partition portions 15aα and 15bα. The face is longer than the length of the end core. Specifically, the length of the end core side surface of the combined body partition portion 15aα is equal to the length of the coil side surface of the combined body partition portion 15aα. The heat radiation table 13α is less likely to warp than the heat radiation table 13 of the first embodiment by including such combination partition portions 15aα and 15bα.

(Heat sink 13β)
In the first embodiment, as the coil recess 140 provided in the heat radiating stand 13, two coil elements 12a and 12b are fitted together, that is, one coil recess 140 is provided for the two coil elements 12a and 12b. Explained the configuration. A configuration may be provided that includes a pair of coil recesses 140a and 140b into which the respective coil elements are respectively fitted, like a heat radiation base 13β shown in FIG. 5 (B). That is, the heat sink 13β includes another partition portion (element partition portion 15c) in addition to the combination partition portions 15a and 15b, and the internal space of one coil recess 140 included in the heat sink 13 of the first embodiment. Is divided into two small spaces by the element partitioning portion 15c, and the small spaces are defined as coil recesses 140a and 140b. The element partitioning portions 15c are arranged in parallel to the axial direction of the coil elements, and are interposed between the coil elements arranged side by side when the combined body is fitted into the heat radiation base 13β. Here, the element partitioning portion 15c has a rectangular plate shape.

  Since the heat sink 13β includes coil recesses 140a and 140b into which the coil elements are respectively fitted, the number of contact points between the combined body and the heat sink (or the position where the combined body is surrounded by the recessed portions) increases. Can be efficiently released through the heat radiating table 13β. Further, when each coil element is fitted in the coil recess 140a, 140b, both end surfaces and both outer surfaces of each coil element are surrounded by the coil recess 140a, 140b, respectively, so that each coil element can be easily positioned. The position is difficult to shift. Furthermore, the heat radiation base 13β is provided with element partitioning portions 15c arranged along the axial direction of the coil and combination partitioning portions 15a and 15b arranged in a direction orthogonal to the axial direction of the coil, thereby dissipating heat. The warp of the base 13β can be more effectively suppressed.

(Heat sink 13γ)
Furthermore, as in the heat radiating table 13γ shown in FIG. 5 (C), the above-described combination partitioning portions 15aα and 15bα of the heat radiating table 13α and the element partitioning portions 15c of the heat radiating table 13β may be provided. The heat radiation base 13γ including these partition portions 15aα, 15bα, and 15c can further effectively suppress warping.

<Embodiment 3>
FIG. 6 (A) is a schematic front view of the reactor of the present invention including a magnetic core having a shape different from that of the first embodiment, and FIG. 6 (B) is a schematic perspective view of a heat radiating table included in the reactor. FIG. 6 (A) shows a state in which the heat sink is cut. Here, the description will focus on the differences from the first embodiment, and the rest of the configuration is the same as that of the first embodiment, and thus the description thereof is omitted.

  In the first embodiment, the configuration in which the end core 11e of the magnetic core 11 protrudes from the coil winding portion 11c has been described. As in the reactor 2 shown in FIG. 6 (A), the outer peripheral surface of the end core 21e of the magnetic core 21 and the outer peripheral surface of the coil winding portion 21c may be flush with each other. In the reactor 2 including such a magnetic core 21, the outer peripheral surface of the coil 12 protrudes from the outer peripheral surface of the magnetic core 21. Therefore, the heat sink 23 includes a bottomed recess 24 into which a portion of the coil 12 that protrudes from the magnetic core 21 is fitted. Further, the heat sink 23 has a partition portion (element partition portion 25c) that divides the internal space of the recess 24 into two small spaces, and the small spaces are coil recesses 240a and 240b into which the coil elements are respectively fitted. .

  Here, the element partitioning portion 25c is a rectangular plate, and is arranged so as to be parallel to the axial direction of the coil element. When the combined body 20 is fitted into the heat sink 23, it is interposed between the coil elements arranged side by side. Is done. Also, each coil element is fitted into each coil recess 240a, 240b, so that both end surfaces and both outer surfaces of each coil element are surrounded by the coil recesses 240a, 240b, respectively. The mounting surface 120 of each coil element is supported in contact with the bottom 24b of each coil recess 240a, 240b. On the other hand, the mounting surface 210e of the end core 21e of the magnetic core 21 is supported by one surface of the heat radiating base 23 (hereinafter referred to as a support surface 23f).

  Like the reactor 1 of the first embodiment, the reactor 2 includes the heat radiating table 23 having the recesses 24, thereby effectively releasing the heat of the coil elements that are likely to be hot through the heat radiating table 23. In addition to being excellent in heat dissipation, it is small and lightweight. In particular, the element partitioning portion 25c is interposed between the coil elements, whereby the heat of the coil 12 can be released more effectively. In addition, by fitting the coil elements into the respective coil recesses 240a and 240b, both end faces and both outer faces of each coil element can be easily positioned, and their positions are not easily displaced. The reactor 2 is configured such that the recess 24 is not a single large recess but a plurality of bottomed recesses, like the reactor 1 of the first embodiment. The mechanical strength of the base 23 can be increased.

  Further, the reactor 2 adjusts the depth of the recess 24, that is, the height of the support surface 23f of the heat sink 23, and each coil element is supported by the bottom 24b of each coil recess 240a, 240b, and the end core 21e In the state where the mounting surface 210e is supported by the support surface 23f of the heat sink 23, the outer peripheral surface of the coil winding portion 21c and the inner peripheral surface 12i of the coil 12 are not in contact with each other. Therefore, this reactor 2 can also omit a bobbin.

  Furthermore, a protrusion may be appropriately provided on the support surface 23f of the heat radiating base 23, and this protrusion may be used as a positioning member for the end core 21e. The projection may be, for example, a plate-like plate body along the outer peripheral surface of the end core 21e, or may be a plurality of small pieces arranged along the outer peripheral surface of the end core 21e. Is not particularly limited.

(Reference example)
FIG. 7 (A) is a schematic front view of a reactor having a fixing structure different from that of Embodiment 1, and FIG. 7 (B) is a schematic perspective view of a heat radiating stand provided in the reactor. FIG. 7 (A) shows a state in which the heat sink is cut. In the first and second embodiments, the form in which the reactor is arranged so that the axial direction of the coil 12 is the horizontal direction has been described. In addition, like the reactor 3 shown in FIG. 7 (A), the coil 12 can be fixed to the fixed object 100 so that the axial direction of the coil 12 is the vertical direction. The basic structure of the reactor 3 is the same as that of the reactor 1 of the first embodiment, and the shape of the radiator 33 is different. Hereinafter, the heat radiating table 33 will be described, and the description of other configurations will be omitted.

  The radiator 33 has a recess (core recess) 34 into which the end core 11e of the magnetic core 11 is fitted. The concave portion 34 is a rectangular box-shaped bottomed concave portion, and a pair of rectangular plate members are erected in parallel from both ends of the bottom portion 34b. The end surface of the rectangular plate material protrudes from one surface of the heat radiating table 33 (support surface 33f that supports the coil 12). These rectangular plate members are interposed between the coil winding portion 11c and the inner peripheral surface 12i of each of the coil elements 12a and 12b when the combined body 10 is fitted in the recess 34, and the magnetic core 11 and the coil 12 are connected. It functions as partitioning portions 35a and 35b for partitioning. When the combined body 10 is fitted into the recess 34, the end surfaces of the coil elements 12a and 12b on the side of the heat radiating base 33 are supported by the support surface 33f of the heat radiating base 33. Note that the fixing structure shown in FIG. 7A can be used, for example, when fixing to a circuit board or the like.

  Like the reactor 1 of the first embodiment, the reactor 3 includes the heat radiating table 33 having the recesses 34, so that the heat of the combined body 10 can be released through the heat radiating table 33. Besides being excellent, it is small and lightweight. In particular, since the partition portions 35a and 35b are interposed between the coil elements 12a and 12b and the coil winding portion 11c, the heat of the coil elements 12a and 12b can be directly transmitted to the heat radiating base 33. In addition, the end core 11e of the magnetic core 11 is fitted into the recess 34, and the partition portions 35a and 35b are inserted between the coil elements 12a and 12b and the coil winding portion 11c, respectively, so that each coil element 12a , 12b can be easily positioned on the end surface of the heat sink 33 and the magnetic core 11, and these positions are not easily displaced. In the reactor 3, although the number of the recesses 34 is one, by providing a plurality of partition portions 35a and 35b, the heat radiating table 33 is hardly warped and the mechanical strength of the heat radiating table 33 can be increased. Further, by providing the partition portions 35a and 35b between the coil elements 12a and 12b and the coil winding portion 11c, a gap can be provided between the coil elements 12a and 12b and the coil winding portion 11c. As a result, the bobbin can be omitted.

  In addition to the recess 34, an annular recess (coil recess) along the end face of each coil element may be provided in the heat dissipation base 33 so that each coil element is fitted. By fitting each coil element into the annular coil recess, the end face and the outer peripheral surface of each coil element on the heat dissipation base 33 side can be positioned. Moreover, since the contact area of a coil element and a heat sink can be enlarged more, heat dissipation is improved.

  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.

  The reactor of the present invention can be suitably used for a component used in a power conversion device such as a converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle, and other reactors used in general industries.

1,2,3 reactor
10,20 Union
11,21 Magnetic core 11c, 21c Coil winding part 11e, 21e End core
110c, 110e, 210e Mounting surface 111e Opposing surface
12 Coil 12a, 12b Coil element 12i Inner peripheral surface 120 Mounting surface
13,13A, 13B, 13C, 13D, 13E, 13α, 13β, 13γ, 23,33 Heat sink
14, 24, 34 Recess 140, 140a, 140b, 240a, 240b Coil recess
141,142,141α, 142α Core recess
14b, 141b, 142b, 24b, 34b Bottom
140s side view
15a, 15b, 15aα, 15bα Assembly partition 15c, 25c Element partition
150a, 150b End face 155 Notch 156 Convex
16 Insertion hole 16B Through hole 16A Bolt hole
23f, 33f Support surface 35a, 35b Partition
100 Fixing target 200 Bolt 210 Nut

Claims (7)

A reactor comprising an annular magnetic core and a coil disposed on the outer periphery of the magnetic core,
A heat dissipating table on which a combination of the magnetic core and the coil is disposed;
The magnetic core includes a coil winding portion in which the coil is disposed and an exposed portion in which the coil is not disposed, and a surface of the exposed portion on the side of the heat sink is the heat sink in the coil winding portion. Protruding from the side surface,
The heat sink has a recess into which a part of the combination is fitted,
The concave portion includes a partition portion that partitions the internal space of the concave portion into a plurality of small spaces ,
The small space is
A coil recess into which the coil is fitted;
A core recess into which the protruding portion of the exposed portion is fitted,
The partition part has a combination partition part interposed between the exposed part of the magnetic core and the end face of the coil,
The reactor characterized in that at least the surface on the side on which the combined body is arranged is made of an insulating material. The coil has a pair of coil elements disposed on the outer periphery of the magnetic core,
The recess is
As the partition part, it has an element partition part interposed between the coil elements,
2. The reactor according to claim 1, wherein the small space has a coil concave portion in which each coil element is fitted to position the coil element. 3. The reactor according to claim 2 , wherein the two coil elements are arranged such that axial directions of the coil elements are parallel to each other. The combination partition part is
4. The coil according to claim 1, wherein an inner peripheral surface of the coil is not in contact with the coil winding portion, and an end surface of the assembly partition portion is in contact with the coil winding portion . The reactor according to item 1 . Said at least one small space is a bottomed recess having a bottom, claim 1-4 in which a portion of the union body fitted in the bottomed recess, characterized in that the contact with the bottom The reactor according to item 1. At least one of the small spaces is a through-hole penetrating from one surface of the heat radiating table to the other surface, and a part of the combination fitted in the through-hole is exposed from the through-hole,
The reactor according to any one of claims 1 to 5 , wherein the exposed portion of the combined body is flush with one surface of the heat radiating stand. The converter using the reactor of any one of Claims 1-6.

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