JP2015170674A - reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor having excellent heat dissipation for a coil and capable of reducing interruption of a flow of magnetic flux generated from the coil.SOLUTION: A reactor 1 includes: a core 2 consisting of a magnetic material; and a coil 3 including a winding part 31 partially buried in the core 2 and composed of spirally winding a conductor wire and a pair of external connection terminals 32 drawn out from the winding part 31 and projected from the core 2. The core 2 includes a magnetic path formation part 21 forming an annular magnetic path including the inner peripheral side and outer peripheral side of the coil 3 and an opening 22 opened so as to expose a part of an outer peripheral surface of the coil 3. At least one of the pair of external connection terminals 32 is located on the opening 22 side nearer than an axis of the winding part 31.

Description

  The present invention relates to a reactor.

  For example, a power conversion device mounted on an electric vehicle, a hybrid vehicle, or the like is known that includes a boosting unit that boosts a power supply voltage to a predetermined voltage. A reactor is used as a component part of the boosting unit. Some reactors have a core made of a magnetic powder mixed resin, a coil that is embedded in the core and in which a conductor wire is spirally wound, and a case that accommodates the core and the coil therein.

In such a reactor, there is a problem that it is difficult to dissipate heat generated in the coil. That is, since the coil is embedded in the core, the heat of the coil must be radiated to the outside through the core, so that the heat radiation efficiency tends to be low. Therefore, the coil temperature tends to rise.
Therefore, in the reactor described in Patent Document 1, in the axial direction, a heat radiating member is interposed between the coil and the end wall portion of the case, and a joining member that joins the heat radiating member and the coil is provided. Thus, the heat of the coil is transferred to the heat dissipating member near the end wall portion of the case through the joining member, and the heat dissipating from the heat dissipating member to the case is intended to promote the heat dissipation of the coil in the axial direction. doing.

JP 2011-233616 A

  However, in the structure described in Patent Document 1, it is difficult to efficiently dissipate the heat of the coil. That is, as described above, the reactor described in Patent Document 1 is intended to dissipate heat in the axial direction of the coil. However, in the coil in which the conductor wire is spirally wound, Since an insulating film or the like is interposed between the two, it is difficult to conduct heat in the axial direction. Therefore, it is difficult to dissipate the heat of the part of the coil far from the heat dissipation member in the axial direction to the heat dissipation member. Rather, heat in the coil in which the conductor wire is wound spirally is conducted along the conductor wire in a spiral manner and is transmitted to the heat radiating member. Then, since the heat radiation path is long and the cross-sectional area of the heat radiation path is small, it is difficult to increase the heat radiation efficiency after all. Therefore, there is room for improvement in the heat dissipation of the coil.

  Moreover, since the coil and the heat radiating member are disposed inside the case and are not exposed from the case, the heat transfer path to the heat radiating body (cooler or the like) outside the case tends to be long. From this point of view, there is room for improvement in the heat dissipation of the coil.

  Further, when the coil is energized, an annular magnetic path including the inner peripheral side and the outer peripheral side of the coil is formed in the core in which the coil is embedded. However, the external connection terminal for connecting the external device drawn out from the coil intersects the magnetic path. Therefore, the flow of magnetic flux generated by the coil is hindered by the external connection terminal, and the performance of the reactor may be deteriorated.

  This invention is made | formed in view of this background, and it is going to provide the reactor which is excellent in the heat dissipation of a coil, and is reduced that the flow of the magnetic flux which a coil emits is prevented.

One embodiment of the present invention includes a core made of a magnetic material,
A coil having a winding part that is partly embedded in the core and spirally winding a conductor wire, and a pair of external connection terminals that are drawn from the winding part and project from the core;
Have
The core includes a magnetic path forming portion that forms an annular magnetic path including an inner peripheral side and an outer peripheral side of the coil, and an opening that is open to expose a part of the outer peripheral surface of the coil. As well as
At least one of the pair of external connection terminals is in the reactor, which is located on the opening side with respect to the axis of the winding portion.

  In the reactor, the coil has an exposed portion exposed from the core in a part of the outer peripheral surface. Therefore, the heat of the coil can be efficiently radiated to the outside from the outer peripheral surface of the coil.

  That is, in a coil formed by winding a conductor wire in a spiral shape, the heat of each part of the coil is directly transferred to the exposed portion of the outer peripheral surface without transferring heat in the axial direction between conductor portions adjacent in the axial direction. Heat can be radiated to the outside. Alternatively, the heat of each part of the coil can be radiated without conducting heat in a spiral manner along the conductor wires for many turns.

  As described above, even if the heat of each part of the coil is the heat of the part away from the exposed part, the movement in the radial direction or the movement in a short distance in the winding direction (for example, within half a circle [phase π)] Therefore, heat can be radiated from the exposed portion of the outer peripheral surface to the outside. As a result, heat dissipation can be improved by shortening the heat dissipation path of the coil.

  Further, since the exposed portion of the coil is exposed from the core, the core does not intervene between the coil and an external radiator (such as a cooler). Therefore, it is easy to reduce the thermal resistance in the heat radiation path from the coil to the heat radiator. As a result, the heat dissipation of the coil can be improved.

  Moreover, the core does not exist outside the exposed portion of the coil exposed from the opening of the core. Therefore, more magnetic flux generated by the coil is formed in a region opposite to the opening than the axis of the winding portion in the magnetic path forming portion of the core. At least one of the external connection terminals is located on the opening side with respect to the axis of the winding part. Thereby, it is reduced that the flow of magnetic flux generated by the coil is blocked by the external connection terminal. As a result, the performance of the reactor is improved.

  As described above, according to the present invention, it is possible to provide a reactor that is excellent in heat dissipation of the coil and that is prevented from being hindered by the flow of magnetic flux generated by the coil.

The bottom side perspective view of a reactor in Example 1. FIG. FIG. 3 is a bottom perspective view of the coil in the first embodiment. Sectional drawing perpendicular | vertical to the axial direction in the state which installed the reactor in Example 1 in the heat radiator. IV-IV line position sectional drawing in FIG. FIG. 4 is a cross-sectional view corresponding to the position of line IV-IV in FIG. The bottom side perspective view of a reactor in other modifications of Example 1. FIG. Sectional drawing perpendicular | vertical to the axial direction of a reactor in the other modification of Example 1. FIG. Sectional drawing perpendicular | vertical to the axial direction of a reactor in the other modification of Example 1. FIG. The bottom side perspective view of a reactor in Example 2. FIG. The bottom side perspective view of a coil in Example 2. FIG. Sectional drawing perpendicular | vertical to the axial direction of a react in the modification of Example 2. FIG. The bottom side perspective view of a coil in other modifications of Example 2. FIG. Sectional drawing perpendicular | vertical to the axial direction of a react in the other modification of Example 2. FIG.

  In this specification, the direction of the winding axis of the conductor wire in the coil is referred to as the axial direction. Further, in the radial direction orthogonal to the winding axis of the coil, the inner side of the coil is referred to as the inner peripheral side, and the outer side is referred to as the outer peripheral side. Of the side surfaces of the coil, the inner peripheral side surface is referred to as an inner peripheral surface, and the outer peripheral side surface is referred to as an outer peripheral surface.

Example 1
Examples of the reactor will be described with reference to FIGS.
As shown in FIG. 1, the reactor 1 of this example includes a core 2 made of a magnetic material and a coil 3.
The coil 3 is partially embedded in the core 2 and spirally wound with a conductor wire, and a pair of external connection terminals 32 that are drawn from the winding part 31 and project from the core 2. And have.
As shown in FIGS. 1 and 3, the core 2 exposes a magnetic path forming portion 21 that forms an annular magnetic path including the inner and outer peripheral sides of the coil 3 and a part of the outer peripheral surface 301 of the coil 3. And an opening 22 that is open to allow the
As shown in FIGS. 3 and 4, at least one of the pair of external connection terminals 32 is located closer to the opening 22 than the axis 35 of the winding portion 31.
In this embodiment, the winding axis direction of the coil 3 is the axial direction X, one side of the axial direction X is the X1 side, and the other side is the X2 side. The height direction of the coil 3 is Z, and the width direction of the coil 3 is Y.

  As shown in FIG. 1, the core 2 and the coil 3 are accommodated inside the case 4. The case 4 has a window portion 46 formed so as to expose a part (exposed portion 33) of the outer peripheral surface 301 of the coil 3 exposed from the opening portion 22 of the core 2.

  The case 4 includes a bottom plate portion 41, a side plate portion 42 erected from the edge of the bottom plate portion 41 in the normal direction of the bottom plate portion 41, and a top plate portion 43 parallel to the bottom plate portion 41 on the opposite side to the bottom plate portion 41. Have The case 4 can be made of aluminum, for example. One side wall of the case 4 is an open surface 45 that is open. However, a lid that closes the open surface 45 may be provided. A window portion 46 is formed in a part of the bottom plate portion 41. A part of the outer peripheral surface 301 of the coil 3 exposed from the opening 22 of the core 2 is exposed from the window 46 to form an exposed portion 33. The exposed portion 33 is formed over the entire length in the axial direction X of the coil 3. That is, the window part 46 and the opening part 22 of the core 2 described later are formed over the entire length in the axial direction X of the coil 3, and a part of the outer peripheral surface 301 of the coil 3 extends over the entire axial direction X. And the exposed part 33 is comprised by exposing from the opening part 22 of the core 2 mentioned later.

  As shown in FIG. 1, the reactor 1 includes a core 2 and a coil 3 accommodated inside a case 4. The core 2 is formed of a magnetic powder mixed resin obtained by mixing magnetic powder such as iron powder with resin such as epoxy. In the case 4, the coil 3 is embedded in the core 2 while exposing the exposed portion 33. The core 2 is filled in the case 4 across the inner peripheral side and the outer peripheral side of the coil 3 and both axial sides. Thereby, the magnetic path formation part 21 which forms the closed magnetic path of the magnetic flux which arises with electricity supply of the coil 3 is comprised by the core 2. FIG.

  As shown in FIG. 2, the coil 3 includes a winding part 31 and a pair of external connection terminals 32. The winding part 31 is formed in a substantially cylindrical shape by winding a flat conductor wire spirally. The conductor wire can be made of copper (Cu). The conductor wire is wound so that the thickness direction which is the short direction in the shape of the cross section orthogonal to the winding direction is the axial direction. The conductor wire is covered with an insulating film (not shown) at portions other than the external connection terminal 32.

  The pair of external connection terminals 32 includes a first terminal 321 and a second terminal 322. The first terminal 321 is formed by being pulled out from the first end portion 31a on the X1 side in the axial direction X of the coil 3 and bent toward the X1 side. The second terminal 322 is formed by being pulled out from the second end portion 31b on the X2 side in the axial direction X of the coil 3 and bent toward the X1 side. That is, both the first terminal 321 and the second terminal 322 are configured to bend in the same direction (X1 side in FIG. 2) parallel to the axial direction X and extend to the X1 side. Therefore, the second terminal 322 extends to the X1 side along the outer peripheral surface 301 of the winding part 31.

  As shown in FIG. 1, the coil 3 has a case 4 in which the axial direction X is parallel to the bottom plate portion 41 and a pair of external connection terminals 32 (first terminal 321 and second terminal 322) are open surfaces 45. It is arrange | positioned so that it may protrude from. As shown in FIG. 3, the pair of external connection terminals 32 is located closer to the opening 22 than the axis 35 of the winding part 31.

  As shown in FIG. 3, at least one of the pair of external connection terminals 32 (both in the present example) is more open than the inner peripheral surface 302 of the portion exposed from the opening 22 in the winding part 31. It is located on the part 22 side. Further, in this example, at least one of the pair of external connection terminals 32 (both in this example) is wound on the wall surface 22a in which the opening 22 of the core 2 is formed as viewed from the axial direction X of the winding part 31. It is located between the turning part 31. Specifically, as shown in FIG. 3, a space portion 36 is formed between the wall surface 22 a and the winding portion 31, and the external connection terminal 32 is located in the space portion 36.

  As shown in FIG. 3, the reactor 1 is fixed to the radiator 6. In this example, the radiator 6 is made of a metal plate that constitutes a part of the cooler 60, and is made of, for example, aluminum. The cooler 60 includes a refrigerant flow path 61 through which a cooling medium flows. The radiator 6 faces the refrigerant flow path 61 and has a plurality of cooling fins 62 protruding toward the refrigerant flow path 61.

  In a state where the reactor 1 is fixed to the radiator 6, an insulating heat transfer member 13 is interposed between the exposed portion 33 of the coil 3 and the radiator 6. The heat transfer member 13 is in close contact with both the exposed portion 33 and the radiator 6. The heat transfer member 13 is made of a material having insulating properties and excellent thermal conductivity. For example, a silicone resin containing a ceramic filler can be used. The heat transfer member 13 may be a sheet-like member, a paste-like heat radiation grease, or the like.

  A recess or the like for positioning and arranging the heat transfer member 13 may be provided on the surface of the radiator 6 where the reactor 1 is mounted, and the heat transfer member 13 may be arranged in the recess. Furthermore, paste-like heat radiation grease or the like may be applied to the installation surface of the heat radiating body 6 on which the bottom plate portion 41 of the case 4 is seated. In this example, the reactor 15 is fixed to the radiator 6 by inserting the bolt 15 into the fixing portion 44 provided in the case 4 and fastening the bolt 15 to the radiator 6.

  The reactor 1 of this example can be used as a component in a power conversion device mounted on, for example, an electric vehicle or a hybrid vehicle. More specifically, the reactor 1 can be used as a component of the boosting unit that boosts the power supply voltage to a predetermined voltage in the power conversion device.

Next, the function and effect of this example will be described.
In the reactor 1, the coil 3 has an exposed portion 33 exposed from the opening 22 of the core 2 in a part of the outer peripheral surface 301. Therefore, the heat of the coil 3 can be efficiently radiated from the outer peripheral surface 301 of the coil 3 to the outside.

  That is, in the coil 3 formed by winding a conductor wire in a spiral shape, the heat of each part of the coil 3 is exposed to the outer peripheral surface 301 without moving heat in the axial direction between conductor portions adjacent in the axial direction X. It is possible to dissipate heat to the outside by moving directly to the portion 33. Or the heat | fever of each part of the coil 3 can be thermally radiated, without making it heat-transfer along the conductor wire for many turns.

  Thus, even if the heat of each part of the coil 3 is the heat of the part away from the exposed part 33, the movement in the radial direction or the short distance in the winding direction (for example, within half a circle [phase π]) Can be radiated from the exposed portion 33 of the outer peripheral surface 301 to the outside. As a result, heat dissipation can be improved by shortening the heat dissipation path of the coil 3.

  Further, since the exposed portion 33 of the coil 3 is exposed from the core 2, the core 2 is not interposed between the coil 3 and the external radiator 6 (cooler 60). Therefore, it is easy to reduce the thermal resistance in the heat radiation path from the coil 3 to the heat radiator 6. As a result, the heat dissipation of the coil 3 can be improved.

Further, since the core 2 does not exist outside the exposed portion 33 of the coil 3 exposed from the opening 22 of the core 2, the magnetic flux generated by the coil 3 is the winding portion 31 in the magnetic path forming portion 21 of the core 2. More than the axial center 35, the area opposite to the opening 22 is formed. At least one of the pair of external connection terminals 32 is located closer to the opening 22 than the axis 35 of the winding portion 31. Thereby, it is reduced that the flow of the magnetic flux generated by the coil 3 in the magnetic path P formed in the magnetic path forming portion 21 of the core 2 is obstructed by the external connection terminal 32. As a result, the performance of the reactor 1 is improved.
In this example, since both of the pair of external connection terminals 32 are located closer to the opening 22 than the axis 35 of the winding part 31, the flow of magnetic flux in the magnetic path P is further inhibited. Reduced.

  In this example, a case 4 that accommodates the core 2 and the coil 3 inside is provided, and the case 4 is a window part that exposes a part (exposed part 33) of the outer peripheral surface 301 of the coil 3 exposed from the opening part 22. 46. As a result, the core 2 and the coil 3 are accommodated by the case 4, so that the handling of the reactor 1 is facilitated and the heat radiation of the coil 3 can be promoted through the window portion 46.

  In this example, the pair of external connection terminals 32 are located closer to the opening 22 than the inner peripheral surface 302 of the portion exposed from the opening 22 in the winding part 31. That is, both of the pair of external connection terminals 32 are located in a region between the wall surface 22a and the inner peripheral surface 302 (a region indicated by symbol w in FIGS. 4 and 5). Thereby, since a pair of external connection terminal 32 will be arrange | positioned in an area | region with few magnetic fluxes, it is further reduced that the flow of the magnetic flux in the magnetic path formation part 21 is inhibited.

  Moreover, in this example, as shown in FIG. 3, when viewed from the axial direction X (see FIG. 2) of the winding part 31, between the wall surface 22 a where the opening 22 of the core 2 is formed and the winding part 31. Is located. Since the winding part 31 has a cylindrical shape and the cross-sectional shape perpendicular to the axial direction is a rectangle with rounded corners, the space part 36 is provided between the winding part 31 and the wall surface 22a on both sides of the exposed part 33. Is formed. The pair of external connection terminals 32 are located in the space 36. Thereby, the space required for arranging the coil 3 can be reduced, and the overall size of the apparatus can be reduced. Moreover, since the heat radiator 6 can be brought close to the exposed portion 33 via the heat transfer member 13, the heat radiation effect of the coil 3 can be improved.

  In this example, the magnetic material forming the core 2 is a resin mixed with magnetic powder (magnetic powder mixed resin). This makes it easy to embed the coil 3 in the core 2 while forming the opening 22 that exposes the exposed portion 33 of the coil 3.

  In this example, the heat transfer member 13 made of a heat conductive material is disposed on the exposed portion 33 that is a part of the outer peripheral surface 301 of the coil 3 exposed from the window portion 46, and the heat transfer member 13 is interposed therebetween. The coil 3 is connected to the cooler 60 (heat radiator 6). Thereby, heat can be efficiently radiated from the exposed portion 33 of the coil 3 to the heat radiating body 6. In particular, by configuring the heat transfer member 13 with a deformable material, the dimensional tolerance in the reactor 1 is absorbed, and the heat transfer member 13 is sufficiently in close contact with both the exposed portion 33 and the heat radiating body 6. The heat dissipation to the radiator 6 can be further improved.

  In addition, since the heat transfer member 13 interposed between the exposed portion 33 of the coil 3 and the radiator 6 is in close contact with both the exposed portion 33 and the radiator 6, the heat of the coil 3 is more efficient. It is possible to radiate heat to the radiator 6.

  In this example, the coil 3 is directly enclosed in the core 2 in the case 4, but as shown in FIG. 5, the coil 3 is covered with a bobbin 5 made of an insulating material to form a coil assembly 12. May be disposed in the case 4 and included in the core 2.

  Specifically, the bobbin 5 includes an inner bobbin 51 that covers the inner peripheral surface 302 of the coil 3, an outer peripheral surface 301 other than the exposed portion 33 of the coil 3, and an outer bobbin 52 that covers a pair of end surfaces in the axial direction. . The bobbin 5 (the inner bobbin 51 and the outer bobbin 52) is made of a resin molded body, for example. A gap between the coil 3 and the bobbin 5 is filled with a filling resin 11.

  In this case, by providing the bobbin 5, the assembly property of the coil 3 with respect to the case 4 can be improved, and the reactor 1 excellent in productivity can be obtained. Further, by providing the bobbin 5, it is possible to prevent the stress due to the expansion and contraction of the coil 3 from directly acting on the core 2, and to improve the durability of the core 2.

  Further, the bobbin 5 includes the inner bobbin 51 and the outer bobbin 52, so that the assembling property between the coil 3 and the bobbin 5 can be improved, and the reactor 1 having excellent productivity can be obtained. In addition, a filling resin 11 is filled in a gap between the coil 3 and the bobbin 5. Thereby, the vibration of the coil 3 can be suppressed and the durability of the reactor 1 can be improved.

  In this example, the core 2 and the coil 3 are accommodated inside the case 4, but the case 4 may not be provided as shown in FIG. 6. Also in this case, a part of the outer peripheral surface 301 of the coil 3 is exposed from the opening 22 of the core 2 to form an exposed portion 33. Also in this modified example, the same operational effects as those of the first embodiment are obtained except for the operational effects of providing the case 4.

  Further, the second terminal 322 (see FIG. 6) on the X2 side of the pair of external connection terminals 32 is positioned outside the winding part 31 in a cross section perpendicular to the axial direction X as shown in FIG. It is good also as bending and shifting to the X1 side (refer FIG. 6) of the axial direction X. In this case, since it becomes easy to bend the 2nd terminal 322 to the X1 side, the reactor 1 excellent in productivity can be obtained. Further, as shown in FIG. 8, the exposed portion 33 of the coil 3 may be located on the inner side of the wall surface 22 a on the opening 22 side of the core 2.

  As described above, according to the present invention, it is possible to provide the reactor 1 that is excellent in heat dissipation of the coil 3 and is reduced in that the flow of magnetic flux generated by the coil 3 is prevented.

(Example 2)
As shown in FIGS. 9 and 10, the present example includes a coil 300 (FIG. 1) of the first embodiment and a coil 300 whose direction of the winding shaft 350 is different by 90 °. In this example, the axial direction of the coil 300 (the direction of the winding shaft 350) is Y. The height direction of the coil 300 is Z, one side of the height direction Z is Z1, and the other side is Z2. The width direction of the coil 300 is X, one side of the width direction X is the X1 side, and the other side is the X2 side. In addition, the same code | symbol is attached | subjected to the component equivalent to the case of Example 1, and the description is abbreviate | omitted.

  In this example, as shown in FIG. 9, the pair of external connection terminals 320 (the first terminal 321 and the second terminal 322) of the coil 300 are drawn out to the X1 side and project from the open surface 45 of the case 4. . As shown in FIG. 10, in the winding part 31 of the coil 300, the conductor wire extends from one first terminal 321 drawn to the X1 side to the X2 side and is bent by 90 ° from the Z2 side to the Z1 side. Further, it is bent 90 ° from the X2 side to the X1 side, further bent 90 ° from the Z1 side to the Z2 side, and then again bent 90 ° from the X1 side to the X2 side, and wound sequentially. The other second terminal 322 is drawn out to the X1 side by bending the conductor wire so that the conductor wire is folded from the X1 side to the X2 side in the winding portion 31 so as to be folded to the X1 side. One first terminal 321 is not bent. Others are the same as in the first embodiment. Also in this example, the same operational effects as in the case of Example 1 are achieved.

  In this example, the second terminal 322 of the coil 300 is a portion where the conductor wire of the winding portion 31 faces the X2 side, and the conductor wire is bent so as to be folded toward the X1 side and drawn out to the X1 side. However, instead of this, the conductor wire is bent from the Z1 side to the Z2 side along the winding part 31, and then from the X2 side to the X1 side (that is, the side opposite to the direction along the winding part 31). The second terminal 322 may be pulled out to the X1 side by being bent 90 degrees.

  Moreover, in this example, although the core 2 and the coil 300 were accommodated inside the case 4, it is good also as not providing the case 4 as shown in FIG. Also in this case, a part of the outer peripheral surface 301 of the coil 300 is exposed from the opening 22 of the core 2 to form an exposed portion 33. Also in this modified example, the same operational effects as those of the first and second embodiments are obtained except for the operational effects of providing the case 4.

  Further, in the modification shown in FIG. 11, the pair of external connection terminals 320 are all drawn out to the X1 side, but instead of this, as shown in FIGS. One of the first terminals 321 may be pulled out to the X1 side, and the other second terminal 322 may be pulled out to the X2 side opposite to the X1 side. In this case, compared with the case where the other second terminal 322 is folded so as to be folded to the X1 side, the reactor 1 can be easily formed, and the reactor 1 having excellent productivity can be obtained.

DESCRIPTION OF SYMBOLS 1 Reactor 2 Core 21 Magnetic path formation part 22 Opening part 3,300 Coil 31 Winding part 301 Outer peripheral surface 302 Inner peripheral surface 32,320 A pair of external connection terminal 33 Exposed part 35,350 Axis center 4 Case 46 Window part

Claims (7)

A core (2) made of a magnetic material;
A part (31) embedded in the core (2) and spirally wound with a conductor wire, and drawn out from the winding part (31) and protruding from the core (2) A coil (3, 300) having a pair of external connection terminals (32),
Have
The core (2) includes a magnetic path forming portion (21) that forms an annular magnetic path including an inner peripheral side and an outer peripheral side of the coil (3, 300), and an outer peripheral surface of the coil (3, 300). And an opening (22) that is open to expose a part of the
At least one of the pair of external connection terminals (32) is located on the opening (22) side of the axis (35) of the winding part (31), and the reactor (1) .   A case (4) for accommodating the core (2) and the coil (3, 300) inside is provided, and the case (4) of the coil (3, 300) exposed from the opening (22). The reactor (1) according to claim 1, further comprising a window (46) exposing a part of the outer peripheral surface.   The both of the pair of external connection terminals (32) are located closer to the opening (22) than the axis of the winding part (31). Reactor (1).   At least one of the pair of external connection terminals (32) has the opening (22) rather than the inner peripheral surface (302) of the portion exposed from the opening (22) in the winding part (31). The reactor (1) according to any one of claims 1 to 3, wherein the reactor (1) is located on a side.   At least one of the pair of external connection terminals (32) includes a wall surface on which the opening (22) of the core (2) is formed as viewed from the axial direction of the winding part (31) and the winding part. It is located between (31), The reactor (1) as described in any one of Claims 1-4 characterized by the above-mentioned.   The reactor (1) according to any one of claims 1 to 5, wherein the magnetic material is a resin mixed with magnetic powder.   A heat transfer member (13) made of a heat conductive material is disposed on the outer peripheral surface of the coil (3, 300) exposed from the opening (22), and the heat transfer member (13) is used to place the heat transfer member (13) through the heat transfer member (13). The reactor (1) according to any one of claims 1 to 6, wherein the coil (3, 300) is configured to be connectable to the cooler (60).

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