Reactor, converter, and power conversion device

Abstract

A reactor provided with a coil comprising a winding wire wound in a spiral shape, and a core formed so as to pass through the inside and outside of the coil, the number of the coil being one, the core having: an intermediate core disposed inside the coil; a side core in which the coil is not disposed and which is disposed in parallel with the intermediate core; a first end core connected to a first end portion of the middle core and a first end portion of the side core; and a second end core connected to a second end portion of the middle core and a second end portion of the side core, the width of the middle core being wider than the width of the side core.

Description

Technical Field

[0001] The present invention relates to a reactor, a converter, and a power conversion device. This application claims priority based on Japanese Patent Application No. 2022-197373 filed on December 9, 2022, and incorporates by reference all the descriptions recited in the Japanese application. Background Art

[0002] The reactor of Patent Document 1 includes a coil and a magnetic core. The coil has a first winding portion and a second winding portion formed by winding a winding wire in a spiral shape. The magnetic core has a first intermediate core, a second intermediate core, a first end core, and a second end core. The first intermediate core is disposed inside the first winding portion. The second intermediate core is disposed inside the second winding portion. The width of the first intermediate core is the same as the width of the second intermediate core. The thickness of the first intermediate core is greater than the width of the first intermediate core. The first end core connects the first end of the first intermediate core and the first end of the second intermediate core. The second end core connects the second end of the first intermediate core and the second end of the second intermediate core. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-351722 Summary of the Invention

[0004] The reactor of the present invention includes a coil formed by winding a winding wire in a spiral shape, and a core formed so as to pass through the inside and outside of the coil. The number of the coils is one. The core has: an intermediate core disposed inside the coil; a side core not disposed inside the coil and disposed in parallel with the intermediate core; a first end core connecting the first end of the intermediate core and the first end of the side core; and a second end core connecting the second end of the intermediate core and the second end of the side core. The width of the intermediate core is wider than the width of the side core. Brief Description of the Drawings

[0005] Figure 1 is a schematic perspective view showing the whole reactor of Embodiment 1. Figure 2 is a schematic perspective view showing a disassembled state of the reactor of Embodiment 1. Figure 3 is Figure 1 a sectional view taken along line III-III. Figure 4 is Figure 1 a sectional view taken along line IV-IV. Figure 5It is an explanatory diagram showing the first outer shape of the coil in the reactor of Embodiment 1, the second outer shape of the first end core, the third outer shape of the intermediate core, and the fourth outer shape of the side core. Figure 6 A configuration diagram schematically showing the power supply system of a hybrid vehicle. Figure 7 It is a circuit diagram showing an example of a power conversion device including a converter. Detailed Embodiment

[0006] [Problems to be Solved by the Present Invention] Further improvement in heat dissipation is desired.

[0007] One object of the present invention is to provide a reactor with excellent heat dissipation.

[0008] [Effects of the Present Invention] The reactor of the present invention has excellent heat dissipation.

[0009] [Explanation of Embodiments of the Present Invention] First, embodiments of the present invention will be listed and explained.

[0010] (1) A reactor according to one aspect of the present invention includes a coil formed of a winding wire wound in a spiral shape, and a core formed so as to pass through the inside and outside of the coil. The number of the coils is one, and the core has: an intermediate core disposed inside the coil; a side core not disposed inside the coil and disposed in parallel with the intermediate core; a first end core connected to the first end of the intermediate core and the first end of the side core; and a second end core connected to the second end of the intermediate core and the second end of the side core. The width of the intermediate core is wider than the width of the side core.

[0011] The reactor of (1) above has excellent heat dissipation. In the reactor of (1) above, since the coil is disposed in the intermediate core having a width wider than that of the side core, the width of the coil is wider compared to a reactor W in which the coil is disposed in an intermediate core having the same width as the side core. When the reactor of (1) above is disposed on a planar setting object, the surface with the wider width of the coil contacts the setting object. Therefore, compared with the reactor W above, the reactor of (1) above can increase the contact area between the coil and the setting object. Therefore, compared with the reactor W above, the reactor of (1) above can easily transfer the heat of the coil to the setting object.

[0012] The reactor of (1) above has excellent inductance. In the reactor of (1) above, since the coil is disposed in the intermediate core having a width wider than that of the side core, the cross-sectional area of the coil can be increased compared to the reactor W above. Therefore, compared with the reactor W above, although the number of coils is one, the inductance can be easily increased in the reactor of (1) above.

[0013] The productivity of the reactor of (1) above is excellent. This is because, compared with the case where the number of coils of the reactor of (1) above is one and the case where the number of coils is plural, the coil is easier to form. In addition, this is because, compared with the case where the number of coils of the reactor of (1) above is one and the case where the number of coils is plural, the number of components is small.

[0014] (2) In the reactor of (1) above, it may also be that, when viewed from a first direction along the axis of the coil, the first outer peripheral shape of the coil is rectangular, the outer peripheral surface of the coil has a first coil surface and a second coil surface that are respectively along the long sides of the first outer peripheral shape and face each other, the outer peripheral surfaces of the first end core and the second end core respectively have a first core surface and a second core surface that face each other, and the first core surfaces of the first end core and the second end core are substantially coplanar with the first coil surface.

[0015] The heat dissipation of the reactor of (2) above is excellent. The first core surface of the first end core and the first core surface of the second end core are substantially coplanar with the first coil surface. When the reactor of (2) above is provided on a planar setting object, the first coil surface, the first core surface of the first end core, and the first core surface of the second end core are in contact with the setting object. Therefore, compared with the reactor X in which the first core surface of the first end core and the first core surface of the second end core are not in contact with the setting object and only the first coil surface of the coil is in contact with the setting object, the contact area between the reactor and the setting object can be increased for the reactor of (2) above. Therefore, compared with the reactor X above, not only the heat of the coil but also the heat of the first end core and the second end core can be easily transferred to the setting object for the reactor of (2) above.

[0016] The reactor of (2) above is not likely to leak magnetic flux from near the end face of the coil. In the reactor of (2) above, since the first core surfaces of the first end core and the second end core are respectively substantially coplanar with the first coil surface, the end face of the coil is covered by the first end core and the second end core. Therefore, compared with the reactor Y in which the end face of the coil is not covered by the first end core and the second end core but is exposed from the first end core and the second end core, it is easier to reduce the leakage magnetic flux from near the end face of the coil for the reactor of (2) above.

[0017] The reactor of (2) above is likely to shorten the length of the reactor along the first direction. If the volumes of the first end core and the second end core are constant, compared with the reactor Y above, the length between the first core surface and the second core surface of the first end core and the length between the first core surface and the second core surface of the second end core are long for the reactor of (2) above. Therefore, if the volumes of the first end core and the second end core are constant, compared with the reactor Y above, it is easier to shorten the length of the first end core and the second end core along the first direction for the reactor of (2) above.

[0018] (3) In the reactor of the above (2), the second core surfaces of the first end core and the second end core may also be substantially coplanar with the second coil surface.

[0019] Compared with the reactor Z in which the reactor of the above (3) is substantially coplanar with the first core surface of the first end core, the first core surface of the second end core, and the first coil surface, and the second core surfaces of the first end core, the second end core, and the second core surface of the intermediate core described later are substantially coplanar, the reactor of the above (3) is less likely to leak magnetic flux from the vicinity of the end face of the coil. This is because, compared with the above reactor Z, the area of the end face of the coil covered by the first end core and the second end core is wide in the reactor of the above (3). Compared with the above reactor Z, the reactor of the above (3) has more options for the surface in contact with the installation object. This is because the reactor of the above (3) can make the first coil surface, the first core surface of the first end core, and the first core surface of the second end core contact the installation object, and can also make the second coil surface, the second core surface of the first end core, and the second core surface of the second end core contact the installation object. If the volumes of the first end core and the second end core are constant, compared with the above reactor Z, the reactor of the above (3) is further likely to shorten the lengths of the first end core and the second end core along the first direction, and thus it is easy to shorten the length of the reactor along the first direction.

[0020] (4) In the reactor of the above (2) or (3), it may also be that the outer peripheral surface of the side core has a first core surface and a second core surface facing each other, and the first core surface of the side core is substantially coplanar with the first coil surface.

[0021] Since the first core surface of the side core of the reactor of the above (4) also contacts the installation object, the heat dissipation performance is excellent.

[0022] (5) In the reactor of the above (4), the second core surface of the side core may also be substantially coplanar with the second coil surface.

[0023] The reactor of the above (5) has more options for the surface in contact with the installation object. This is because the reactor of the above (5) can also make the first coil surface, the first core surface of the first end core, the first core surface of the second end core, and the first core surface of the side core contact the installation object, and can also make the second coil surface, the second core surface of the first end core, the second core surface of the second end core, and the second core surface of the side core contact the installation object.

[0024] (6) In the reactor of the above (5), the first end and the second end of the winding wire may also be led out in the respective directions along the long side.

[0025] When the reactor of the above (6) is arranged on a planar object to be arranged, the first coil surface, the first core surface of the first end core, the first core surface of the second end core, and the first core surface of the side core can contact the object to be arranged without interfering with the first end and the second end of the winding wire.

[0026] (7) In the reactor of the above (6), it is also possible that the second outer peripheral shapes of the first end core and the second end core viewed from the first direction are rectangular, and the first core surfaces and the second core surfaces of the first end core and the second end core are the surfaces along the long sides of the second outer peripheral shapes respectively.

[0027] In the reactor of the above (7), since the first core surfaces of the first end core and the second end core are wide surfaces, it is easy to increase the contact area between the reactor and the object to be arranged. In the reactor of the above (7), since the second core surfaces of the first end core and the second end core are wide surfaces, it is easy to increase the contact area between the reactor and the object to be arranged.

[0028] (8) A converter according to an aspect of the present invention includes the reactor according to any one of the above (1) to the above (7).

[0029] Since the above converter includes the above reactor, it has excellent performance.

[0030] (9) A power conversion device according to an aspect of the present invention includes the converter according to the above (8).

[0031] Since the above power conversion device includes the above converter, it has excellent performance.

[0032] Details of Embodiments of the Present Invention Details of embodiments of the present invention will be described below with reference to the drawings. The same reference numerals in the drawings denote the same objects.

[0033] Embodiment 1 〔Reactor〕 Refer to Figures 1 to 5 The reactor 1 of Embodiment 1 will be described. As Figure 1 shown, the reactor 1 includes a coil 2 and a core 3. The coil 2 is composed of a winding wire 20 wound in a spiral shape. The core 3 forms a magnetic path passing through the inside and outside of the coil 2. One of the features of the reactor 1 of the present embodiment is in terms of satisfying the following requirements (a) to (c). (a) The number of coils 2 is one. (b) The planar shape of the core 3 is an O shape. (c) The coil 2 and the intermediate core 31 arranged inside the coil 2 are of specific shapes.

[0034] In the following description, the first direction D1, the second direction D2, and the third direction D3 defined as follows are sometimes used. The first direction D1 is the direction along the axis of the coil 2. The second direction D2 is as Figure 5 shown, the direction along the first long side L11 described later. The third direction D3 is the direction orthogonal to both the first direction D1 and the second direction D2. The length along the second direction D2 is called the width. The length along the third direction D3 is called the thickness. The shape of the core 3 viewed from the third direction D3 is a planar shape.

[0035] [Coil] As Figure 1 , Figure 2 shown, the number of coils 2 is one. Comparing the reactor 1 with one coil 2 and the case where the number of coils 2 is plural, the coil 2 is easier to form. Comparing the reactor 1 with one coil 2 and the case where the number of coils 2 is plural, the number of components is small. Therefore, the productivity of the reactor 1 with one coil 2 is excellent. By the number of coils 2 being one, compared with the case where a plurality of coils 2 are arranged in parallel in the second direction D2, the width of the reactor 1 can be shortened. The shape of the coil 2 is a rectangular cylindrical shape. By the shape of the coil 2 being a rectangular cylindrical shape, compared with the case where the coil 2 is a circular cylindrical shape with the same cross-sectional area, it is easy to increase the contact area between the coil 2 and the planar setting object. Therefore, it is easy for the reactor 1 to transfer the heat of the coil 2 to the setting object. The setting object is, for example, a cooling base. The four corners of the coil 2 are rounded. As Figure 5 shown, the first outer peripheral shape C1 of the coil 2 viewed from the first direction D1 is a rectangle. That is, the end face shape of the coil 2 viewed from the first direction D1 is a rectangular frame shape. Figure 5 shows the state where the reactor 1 is cut at the same position as Figure 4 . For ease of explanation, Figure 5 the first outer peripheral shape C1 shown is represented by a double-dot chain line larger than the outer peripheral contour line of the coil 2 to distinguish it from the outer peripheral contour line of the coil 2.

[0036] As Figure 3 shown, the outer peripheral surface of the coil 2 has a first coil surface 251 and a second coil surface 252 facing each other. The first coil surface 251 is along the Figure 5 first long side L11 of the rectangular first outer peripheral shape C1 shown. The second coil surface 252 is along the Figure 5 second long side L12 of the rectangular first outer peripheral shape C1 shown. The first coil surface 251 and the second coil surface 252 are flat surfaces.

[0037] As Figure 1 , Figure 2 shown, the winding wire 20 that constitutes the coil 2 is a continuous winding wire without a joint. The winding wire 20 is a well-known winding wire. The winding wire 20 of the present embodiment uses a covered flat wire. The conductor wire of the covered flat wire is composed of a flat wire made of copper. The insulating coating portion of the covered flat wire is composed of enamel paint. The coil 2 of the present embodiment is formed by flat-standing winding of the covered flat wire. Different from the present embodiment, the coil 2 can also be formed by flat winding of the covered flat wire.

[0038] In the present embodiment, the first end portion 21 of the winding wire 20 is led out in the direction along the first long side L11 of the first outer peripheral shape C1 of the rectangle shown in Figure 5 , that is, in the direction along Figure 1 , Figure 2 shown, at the first end portion in the first direction D1 of the coil 2. The second end portion 22 of the winding wire 20 is led out in the direction along the second long side L12 of the first outer peripheral shape C1 of the rectangle shown in Figure 5 , that is, in the direction along Figure 1 , Figure 2 shown, at the second end portion in the first direction D1 of the coil 2. The first end portion 21 and the second end portion 22 are led out in the same direction. The first end portion 21 and the second end portion 22 are led out in a manner away from the side core 32 described later.

[0039] Although the illustration of the first end portion 21 and the second end portion 22 is omitted, the insulating coating portion is peeled off to expose the conductor wire. A terminal member is connected to the exposed conductor wire. The illustration of the terminal member is omitted. The external device is connected to the coil 2 through the terminal member. The illustration of the external device is omitted. The external device is, for example, a power supply that supplies power to the coil 2.

[0040] [Core] As Figure 1 shown, the planar shape of the core 3 is O-shaped. As Figure 1 , Figure 2 shown, the core 3 has a first end core 35, a second end core 36, an intermediate core 31, and a side core 32.

[0041] (First end core · Second end core) The first end core 35 connects the first end portion of the intermediate core 31 and the first end portion of the side core 32. The second end core 36 connects the second end portion of the intermediate core 31 and the second end portion of the side core 32. The shapes of the first end core 35 and the second end core 36 are the same shape. The shapes of the first end core 35 and the second end core 36 are prismatic.

[0042] In the present embodiment, as Figure 5As shown, the second outer peripheral shape C2 of the first end core 35 viewed from the first direction D1 is rectangular. For ease of explanation, Figure 5 the second outer peripheral shape C2 shown is represented by a double-dot dash line larger than the outer peripheral contour line of the first end core 35 to distinguish it from the outer peripheral contour line of the first end core 35. Although not shown, the second outer peripheral shape of the second end core 36 viewed from the first direction D1 is also rectangular. Although the four corners of the second outer peripheral shape C2 are angular, they may also be rounded. As Figure 4 , Figure 5 shown, the width of the first end core 35 is greater than the thickness of the first end core 35. The width of the second end core 36 is greater than the thickness of the second end core 36. The width of the first end core 35 and the width of the second end core 36 are the same as each other. The thickness of the first end core 35 and the thickness of the second end core 36 are the same as each other.

[0043] As Figure 3 , Figure 4 shown, the outer peripheral surface of the first end core 35 has a first core surface 351 and a second core surface 352 facing each other. The first core surface 351 extends along the Figure 5 first long side L21 of the rectangular second outer peripheral shape C2 shown. The second core surface 352 extends along the Figure 5 second long side L22 of the rectangular second outer peripheral shape C2 shown. In the present embodiment, as Figure 1 , Figure 2 shown, the planar shapes of the first core surface 351 and the second core surface 352 are trapezoids whose widths narrow from the first end face of the first end core 35 close to the middle core 31 and the side core 32 toward the second end face away from them.

[0044] As Figure 2 , Figure 3 shown, the outer peripheral surface of the second end core 36 has a first core surface 361 and a second core surface 362 facing each other. The first core surface 361 extends along the first long side of the rectangular second outer peripheral shape. The second core surface 362 extends along the second long side of the rectangular second outer peripheral shape. In the present embodiment, as Figure 1 , Figure 2 shown, the planar shapes of the first core surface 361 and the second core surface 362 are trapezoids whose widths narrow from the first end face of the second end core 36 close to the middle core 31 and the side core 32 toward the second end face away from them.

[0045] In the present embodiment, as Figure 3 shown, the first core surface 351 and the first core surface 361 are substantially coplanar with the first coil surface 251. By being substantially coplanar, the maximum difference in the third direction D3 between the first core surface 351 and the first core surface 361 and the first coil surface 251 can be reduced, and the above maximum difference can be made close to 0 (zero). As described above, the first end portion 21 and the second end portion 22 of the reactor 1 extend along Figure 5The first long sides L11 and the second long sides L12 of the first outer peripheral shape C1 of the shown rectangle are led out, and the first coil surface 251, the first core surface 351, and the first core surface 361 are coplanar. Therefore, when the reactor 1 is arranged on a planar object to be arranged, the reactor 1 can make the first coil surface 251, the first core surface 351, and the first core surface 361 contact the object to be arranged without the first end 21 and the second end 22 interfering with the object to be arranged. Therefore, compared with the reactor X in which the reactor 1, the first core surface 351, and the first core surface 361 do not contact the object to be arranged and only the first coil surface 251 contacts the object to be arranged, the contact area between the reactor 1 and the object to be arranged can be increased.

[0046] In particular, the first core surface 351 and the second core surface 352 are wide surfaces by following Figure 5 the first long sides L21 and the second long sides L22 of the second outer peripheral shape C2 of the shown rectangle, and thus the contact area with the object to be arranged can be increased. Compared with the above-mentioned reactor X, not only the heat of the coil 2 but also the heat of the first end core 35 and the second end core 36 is easily transferred to the object to be arranged. Therefore, the heat dissipation performance of the reactor 1 is more easily improved compared with the above-mentioned reactor X. That is, Figure 3 the first core surface 351, the first core surface 361, and the first coil surface 251 shown are substantially coplanar, which means that the thicknesses of the first end core 35, the second end core 36, and the coil 2 are dimensions that can easily ensure heat dissipation performance. The flatness of the substantially coplanar first core surface 351, first core surface 361, and first coil surface 251 can be, for example, 0.4 mm or less, and further can also be 0.2 mm or less, 0.1 mm or less, 0.05 mm or less. The flatness mentioned here is based on the definition and representation of geometric deviations in JIS B 0621:1984.

[0047] In the reactor 1, since the first core surface 351 and the first core surface 361 are substantially coplanar with the first coil surface 251, the end faces of the coil 2 are covered by the first end core 35 and the second end core 36. That is, the end faces of the coil 2 face the first end core 35 and the second end core 36. Therefore, compared with the reactor Y in which the end faces of the coil 2 are not covered by the first end core 35 and the second end core 36 but are exposed from the first end core 35 and the second end core 36, it is easier to reduce the leakage magnetic flux from the vicinity of the end faces of the coil 2. Therefore, compared with the above-mentioned reactor Y, the reactor 1 is not likely to leak magnetic flux from the vicinity of the end faces of the coil 2. Different from this embodiment, the first core surface 351 and the first core surface 361 may not be coplanar with the first coil surface 251.

[0048] In the present embodiment, the second core surfaces 352 and 362 are substantially coplanar with the second coil surface 252. By being substantially coplanar, the maximum difference in the third direction D3 between the second core surfaces 352 and 362 and the second coil surface 252 can be reduced, and the above-mentioned maximum difference can be made close to 0 (zero). The reactor 1 is substantially coplanar with the first core surfaces 351 and 361 and the first coil surface 251. Compared with the reactor Z in which the second core surfaces 352, 362, and the second core surface 312 are substantially coplanar, it is less likely to leak magnetic flux from near the end surface of the coil 2. This is because, compared with the above-mentioned reactor Z, the area of the end surface of the coil 2 covered by the first end core 35 and the second end core 36 is wide. That is, because the area of the end surface of the coil 2 facing the first end core 35 and the second end core 36 is wide. Compared with the above-mentioned reactor Z, the reactor 1 has more options for the surface in contact with the installation object. This is because the reactor 1 can make the first coil surface 251, the first core surfaces 351 and 361 contact the installation object, and can also make the second coil surface 252, the second core surfaces 352 and 362 contact the installation object. Figure 3 The second core surfaces 352 and 362 and the second coil surface 252 shown are substantially coplanar, which can be said that the thicknesses of the first end core 35, the second end core 36, and the coil 2 are dimensions that can easily ensure heat dissipation. The flatness of the substantially coplanar second core surfaces 352, 362, and the second coil surface 252 can be, for example, 0.4 mm or less, and further can be 0.2 mm or less, 0.1 mm or less, 0.05 mm or less. Different from the present embodiment, the second core surfaces 352 and 362 may not be coplanar with the second coil surface 252.

[0049] (Intermediate core) As Figure 1 、 Figure 3 、 Figure 4 shown, the intermediate core 31 has a portion disposed inside the coil 2. The shape of the intermediate core 31 is a shape corresponding to the inner peripheral contour shape of the coil 2. The shape of the intermediate core 31 is a quadrangular prism. As Figure 5 shown, the third outer peripheral shape C3 of the intermediate core 31 viewed from the first direction D1 is a rectangle. For the convenience of explanation, Figure 5 the third outer peripheral shape C3 shown is represented by a double-dot dash line larger than the outer peripheral contour line of the intermediate core 31 to distinguish it from the outer peripheral contour line of the intermediate core 31. The four corner portions of the third outer peripheral shape C3 are each rounded in the manner of the four corner portions of the inner peripheral surface of the coil 2. The intermediate core 31 and the side core 32 are arranged side by side along the first long side L31 of the third outer peripheral shape C3.

[0050] The width of the middle core 31 is greater than the thickness of the middle core 31. The width of the middle core 31 is greater than the width of the side core 32. The reactor 1 has a coil 2 disposed on the middle core 31 that is wider than the side core 32 in width. Compared with the reactor W having a coil 2 disposed on the middle core 31 with the same width as the side core 32, the width of the coil 2 is wider. When the reactor 1 is disposed on a planar object to be disposed, the surface with the wider width of the coil 2 contacts the object to be disposed. Therefore, the reactor 1 can increase the contact area between the coil 2 and the object to be disposed compared with the above-mentioned reactor W. The reactor 1 can transfer the heat of the coil 2 to the object to be disposed more easily compared with the above-mentioned reactor W. Therefore, the heat dissipation performance of the reactor 1 is excellent. The reactor 1 has a coil 2 disposed on the middle core 31 that is wider than the side core 32 in width, and can increase the cross-sectional area of the coil 2 compared with the above-mentioned reactor W. Therefore, the reactor 1 can easily increase the inductance although the number of coils 2 is one compared with the above-mentioned reactor W. Therefore, the inductance of the reactor 1 is excellent. The thickness of the middle core 31 is less than the thickness of the first end core 35.

[0051] The outer peripheral surface of the middle core 31 has a first core surface 311 and a second core surface 312 that face each other. The first core surface 311 is along Figure 5 the first long side L31 of the rectangular third outer peripheral shape C3 shown. The second core surface 312 is along Figure 5 the second long side L32 of the rectangular third outer peripheral shape C3 shown. The middle core 31 of the present embodiment is composed of two core parts, a first middle core part 31f and a second middle core part 31s. Different from the present embodiment, the middle core 31 may also be composed of a single member.

[0052] (Side core) As Figure 1 、 Figure 2 shown, the side core 32 is not configured with a coil 2 and is arranged in parallel with the middle core 31. The shape of the side core 32 is a quadrangular prism. As Figure 5 shown, the fourth outer peripheral shape C4 of the side core 32 viewed from the first direction D1 is a rectangle. For the sake of easy explanation, Figure 5 the fourth outer peripheral shape C4 shown is represented by a double-dot dash line larger than the outer peripheral contour line of the side core 32 to distinguish it from the outer peripheral contour line of the side core 32. Although the four corners of the fourth outer peripheral shape C4 are angular, they may also be rounded.

[0053] The width of the side core 32 is greater than the thickness of the side core 32. The thickness of the side core 32 of the present embodiment is greater than the thickness of the middle core 31. Different from the present embodiment, the thickness of the side core 32 may also be the same as the thickness of the middle core 31. The thickness of the side core 32 of the present embodiment is the same as the thickness of the first end core 35 and the second end core 36. Different from the present embodiment, the thickness of the side core 32 may also be less than the thickness of the first end core 35 and the second end core 36.

[0054] As Figure 2 、 Figure 4 shown, the outer peripheral surface of the side core 32 has a first core surface 321 and a second core surface 322 that face each other. As Figure 5 shown, the first core surface 321 extends along the first long side L41 of the rectangular fourth outer peripheral shape C4. The second core surface 322 extends along the second long side L42 of the rectangular fourth outer peripheral shape C4.

[0055] The first core surface 321 of the present embodiment is substantially coplanar with the first coil surface 251. That is, as Figure 1 shown, the first core surface 321 of the present embodiment is also substantially coplanar with the first core surface 351 and the first core surface 361. By being substantially coplanar, the maximum difference along the third direction D3 between the first core surface 321 and the first coil surface 251 can be reduced, and the above maximum difference can be made close to 0 (zero). Since the first core surface 321 of the reactor 1 also contacts the object to be provided, the heat dissipation performance is excellent. The flatness of the first core surface 321 that is substantially coplanar with the first coil surface 251 can be, for example, 0.4 mm or less, and further can be 0.2 mm or less, 0.1 mm or less, 0.05 mm or less. Different from the present embodiment, the first core surface 321 may not be coplanar with the first coil surface 251.

[0056] As Figure 4 shown, the second core surface 322 of the present embodiment is substantially coplanar with the second coil surface 252. That is, the second core surface 322 of the present embodiment is also substantially coplanar with the second core surface 352 and the second core surface 362. By being substantially coplanar, the maximum difference along the third direction D3 between the second core surface 322 and the second coil surface 252 can be reduced, and the above maximum difference can be made close to 0 (zero). There are more options for the surface of the reactor 1 that contacts the object to be provided. This is because the reactor 1 can also bring the first coil surface 251, the first core surface 351, the first core surface 361, and the first core surface 321 into contact with the object to be provided, and can also bring the second coil surface 252, the second core surface 352, the second core surface 362, and the second core surface 322 into contact with the object to be provided. The flatness of the second core surface 322 that is substantially coplanar with the second coil surface 252 can be, for example, 0.4 mm or less, and further can be 0.2 mm or less, 0.1 mm or less, 0.05 mm or less. Different from the present embodiment, the second core surface 322 may not be coplanar with the second coil surface 252.

[0057] As Figure 1As shown, the length of the side core 32 along the first direction D1 is longer than the length of the middle core 31 along the first direction D1. The length of the middle core 31 along the first direction D1 does not include the length of the later-described spacer portion 3g along the first direction D1. The same applies to the lengths of the other cores. The length of the middle core 31 along the first direction D1 is the total length of the length of the later-described first middle core portion 31f along the first direction D1 and the length of the second middle core portion 31s along the first direction D1. The side core 32 of the present embodiment is composed of two core portions, a first side core portion 32f and a second side core portion 32s. The length of the side core 32 along the first direction D1 is the total length of the length of the later-described first side core portion 32f along the first direction D1 and the length of the second side core portion 32s along the first direction D1.

[0058] As Figure 1 , Figure 2 shown, the core 3 of the present embodiment is an assembly combining the first core 3f and the second core 3s. The combination of the first core 3f and the second core 3s can be set to various combinations by appropriately selecting the shapes of the first core 3f and the second core 3s. The shapes of the first core 3f and the second core 3s can be either symmetric or asymmetric with respect to each other. Symmetric means having the same shape and dimensions. Asymmetric means having different shapes. In the present embodiment, the shapes of the first core 3f and the second core 3s are symmetric. In the present embodiment, the first core 3f and the second core 3s are divided along the first direction D1. In the present embodiment, the combination of the first core 3f and the second core 3s is a U-U type. Although not shown for simplicity, the above combination can also be a U-I type, a J-L type, a J-J type, or an L-L type. The reactor 1 can be constructed by combining the first core 3f and the second core 3s with respect to the coil 2 along the axis of the coil 2. Therefore, the manufacturing workability of the reactor 1 is excellent. A later-described spacer portion 3g may or may not be provided between the first core 3f and the second core 3s. Different from the present embodiment, the core 3 may also be an integral body.

[0059] (First Core) The first core 3f has at least one selected from the group consisting of at least a part of the intermediate core 31 and at least a part of the side core 32, and the first end core 35. For example, when the first core 3f has at least a part of the intermediate core 31 or at least a part of the side core 32 and the first end core 35, the planar shape of the first core 3f is L-shaped. When the first core 3f has at least a part of the intermediate core 31, at least a part of the side core 32, and the first end core 35, the planar shape of the first core 3f is U-shaped or J-shaped. When the lengths of a part of the intermediate core 31 and a part of the side core 32 along the first direction D1 are the same, the planar shape of the first core 3f is U-shaped. When the lengths of a part of the intermediate core 31 and a part of the side core 32 along the first direction D1 are different, the planar shape of the first core 3f is J-shaped.

[0060] The planar shape of the first core 3f in the present embodiment is U-shaped. The first core 3f in the present embodiment has a first intermediate core portion 31f, a first side core portion 32f, and a first end core 35. The first core 3f is an integrally formed body of the first intermediate core portion 31f, the first side core portion 32f, and the first end core 35. In Figure 1 , Figure 2 , for the convenience of explanation, the boundary between the first side core portion 32f and the first end core 35 is indicated by a two-dot chain line. The first end core 35 connects the first intermediate core portion 31f and the first side core portion 32f. The first intermediate core portion 31f and the first side core portion 32f are provided at both ends of the first end core 35 in the direction along its width.

[0061] (Second core) According to the combination of the first core 3f and the second core 3s, the second core 3s may be composed of only the second end core 36, or may have at least one selected from the group consisting of the remaining part of the intermediate core 31 and the remaining part of the side core 32, and the second end core 36. For example, when the second core 3s is composed of one second end core 36, the planar shape of the second core 3s is I-shaped. When the second core 3s has the remaining part of the intermediate core 31 or the remaining part of the side core 32 and the second end core 36, the planar shape of the second core 3s is L-shaped. When the second core 3s has the remaining part of the intermediate core 31, the remaining part of the side core 32, and the second end core 36, the planar shape of the second core 3s is U-shaped or J-shaped. When the lengths of the remaining part of the intermediate core 31 and the remaining part of the side core 32 along the first direction D1 are the same, the planar shape of the second core 3s is U-shaped. When the lengths of the remaining part of the intermediate core 31 and the remaining part of the side core 32 along the first direction D1 are different, the planar shape of the second core 3s is J-shaped.

[0062] The planar shape of the second core 3s of this embodiment is U-shaped. The second core 3s of this embodiment has a second intermediate core portion 31s, second side core portions 32s, and a second end core 36. The second core 3s is a formed body in which the second intermediate core portion 31s, the second side core portions 32s, and the second end core 36 are integrated. In Figure 1 , Figure 2 , for the convenience of explanation, the boundary between the second side core portion 32s and the second end core 36 is indicated by a double-dashed line. The second end core 36 connects the second intermediate core portion 31s and the second side core portions 32s. The second intermediate core portion 31s and the second side core portions 32s are provided at both ends of the second end core 36 in the direction along its width.

[0063] In this embodiment, the length of the first intermediate core portion 31f along the first direction D1 is shorter than the length of the first side core portion 32f along the first direction D1.

[0064] Different from this embodiment, the length of the first intermediate core portion 31f along the first direction D1 may also be longer than the length of the second intermediate core portion 31s along the first direction D1. The length of the first side core portion 32f along the first direction D1 may also be longer than the length of the second side core portion 32s along the first direction D1. The length of the first intermediate core portion 31f along the first direction D1 may also be equal to the length of the first side core portion 32f along the first direction D1.

[0065] In this embodiment, the first core 3f and the second core 3s are combined in such a way that the end face of the first side core portion 32f contacts the end face of the second side core portion 32s. When combined in this way, since the above length relationship is satisfied, there is a gap between the end face of the first intermediate core portion 31f and the end face of the second intermediate core portion 31s. An interval portion 3g is formed between the end face of the first intermediate core portion 31f and the end face of the second intermediate core portion 31s. The interval portion 3g is composed of a member made of a material having a relative magnetic permeability smaller than that of the first core 3f and the second core 3s. The interval portion 3g is composed of the same resin as the resin of the formed body of the composite material described later. The interval portion 3g may also be composed of a mixed material containing the filler described later in the above resin.

[0066] Each of the first core 3f and the second core 3s is composed of a formed body of a composite material or a compacted powder formed body. In this embodiment, the first core 3f is composed of a formed body of a composite material, and the second core 3s is composed of a compacted powder formed body. Different from this embodiment, both the first core 3f and the second core 3s may be composed of formed bodies of composite materials, or may be composed of compacted powder formed bodies.

[0067] The formed body of the composite material is a formed body in which soft magnetic powder is dispersed in a resin. The formed body of the composite material is obtained by filling a mold with a fluid raw material in which soft magnetic powder is dispersed in an uncured resin and curing the resin. The formed body of the composite material can easily adjust the content of the soft magnetic powder in the resin. Therefore, the magnetic properties of the formed body of the composite material can be easily adjusted. Moreover, compared with the compacted powder formed body, the formed body of the composite material is easy to form even in a complex shape. The content of the soft magnetic powder in the formed body of the composite material is, for example, 20% by volume or more and 80% by volume or less. The content of the resin in the formed body of the composite material is, for example, 20% by volume or more and 80% by volume or less. These contents are ratios with respect to when the volume of the formed body of the composite material is set to 100%.

[0068] The compacted powder formed body is a formed body obtained by compacting soft magnetic powder. Compared with the formed body of the composite material, the proportion of the soft magnetic powder in the core can be increased. Therefore, the magnetic properties of the compacted powder formed body can be easily improved. Examples of the magnetic properties include relative magnetic permeability or saturation magnetic flux density. In addition, compared with the formed body of the composite material, the amount of resin is small and the amount of soft magnetic powder is large in the compacted powder formed body, so the heat dissipation property is excellent. The content of the soft magnetic powder in the compacted powder formed body is, for example, 85% by volume or more and 99% by volume or less. This content is a ratio with respect to when the volume of the compacted powder formed body is set to 100%.

[0069] The particles constituting the soft magnetic powder are, for example, soft magnetic metal particles, coated particles, or soft magnetic non-metal particles. The coated particles include soft magnetic metal particles and an insulating coating portion provided on the outer periphery of the soft magnetic metal particles. The soft magnetic metal is, for example, pure iron or an iron-based alloy. The iron-based alloy is, for example, an Fe-Si alloy or an Fe-Ni alloy. The insulating coating portion is, for example, phosphate. The soft magnetic non-metal is, for example, ferrite.

[0070] The resin of the formed body of the composite material is, for example, a thermosetting resin or a thermoplastic resin. The thermosetting resin is, for example, an epoxy resin, a phenol resin, a silicone resin, or a polyurethane resin. The thermoplastic resin is, for example, a polyphenylene sulfide resin, a polyamide resin, a liquid crystal polymer, a polyimide resin, or a fluororesin. The polyamide resin is, for example, nylon 6, nylon 66, or nylon 9T.

[0071] The formed body of the composite material may also contain a filler. The filler is, for example, alumina or silica. The filler helps to improve the heat dissipation property and the electrical insulation property.

[0072] The content of the soft magnetic powder in the formed body of the composite material and the content of the soft magnetic powder in the compacted powder formed body are regarded as equivalent to the area ratio of the soft magnetic powder in the cross-section of the formed body. The content of the soft magnetic powder in the formed body is obtained as follows. The cross-section of the formed body is observed with an SEM (scanning electron microscope) to obtain an observation image. The cross-section of the formed body is an arbitrary cross-section. The magnification of the SEM is 200 times or more and 500 times or less. The number of observation images obtained is 10 or more. The longitudinal cross-sectional area is 0.1 cm 2 or more. One observation image can be obtained for one cross-section, or multiple observation images can be obtained for one cross-section. Image processing is performed on each of the obtained observation images to extract the contours of the particles. Examples of image processing include binary processing. The area ratio of the soft magnetic particles is calculated in each observation image, and the average value of the area ratio is obtained. This average value is regarded as the content of the soft magnetic powder.

[0073] 《Embodiment 2》 〔Converter · Power Conversion Device〕 The reactor 1 of Embodiment 1 can be used for applications that satisfy the following energization conditions. As the energization conditions, for example, the following can be cited: the maximum DC current is on the order of 100 A or more and 1000 A or less, the average voltage is on the order of 100 V or more and 1000 V or less, and the operating frequency is on the order of 5 kHz or more and 100 kHz or less. The reactor 1 of Embodiment 1 can typically be used as a component of a converter mounted on a vehicle 1200 of an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, or as a component of a power conversion device having such a converter.

[0074] As Figure 6 shown, the vehicle 1200 includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and an electric motor 1220 that is driven by the supplied power from the main battery 1210 and is used for driving. The electric motor 1220 is typically a three-phase AC motor. The electric motor 1220 drives the wheels 1250 during driving and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 further includes an engine 1300 in addition to the electric motor 1220. In Figure 6 it, an example is shown in which the charging part of the vehicle 1200 is a socket. Although not shown, it can be configured such that the charging part of the vehicle 1200 has a plug.

[0075] The power conversion device 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110. The inverter 1120 performs mutual conversion between direct current and alternating current. The converter 1110 shown in this example boosts the input voltage of the main battery 1210, which is above 200V and below 300V, to above 400V and below 700V and supplies power to the inverter 1120 when the vehicle 1200 is running. The converter 1110 steps down the input voltage output from the motor 1220 to a DC voltage suitable for the main battery 1210 and charges the main battery 1210 during regeneration. The input voltage is a DC voltage. The inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC and supplies power to the motor 1220 when the vehicle 1200 is running. The inverter 1120 converts the AC output from the motor 1220 into DC and outputs it to the converter 1110 during regeneration.

[0076] As Figure 7 shown, the converter 1110 includes a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115, and performs conversion of the input voltage by repeating on / off. The conversion of the input voltage here is to perform step-up and step-down. The switching elements 1111 use power devices such as field effect transistors and insulated gate bipolar transistors. The reactor 1115 has the following function: using the coil property that wants to prevent the change of the current flowing through the circuit, when the current is about to increase or decrease due to the switching operation, making its change smooth. As the reactor 1115, the reactor 1 of Embodiment 1 is provided. By providing this reactor 1, the power conversion device 1100 or the converter 1110 has excellent performance.

[0077] In addition to the converter 1110, the vehicle 1200 also includes a power supply converter 1150 connected to the main battery 1210 and an auxiliary power supply converter 1160 that converts the high voltage of the main battery 1210 into a low voltage. The auxiliary power supply converter 1160 is connected to the sub-battery 1230 that is the power source of the auxiliary equipment 1240 and the main battery 1210. The converter 1110 typically performs DC-DC conversion. The power supply converter 1150 or the auxiliary power supply converter 1160 performs AC-DC conversion. There is also a case where the power supply converter 1150 performs DC-DC conversion. In the reactors of the power supply converter 1150 and the auxiliary power supply converter 1160, reactors having the same structure as the reactor 1 of Embodiment 1, etc., and appropriately changed in size or shape, etc., can be used. In addition, converters that perform conversion of input power and only step-up converters and step-down converters can also use the reactor 1 of Embodiment 1, etc.

[0078] The present invention is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. Description of Reference Numerals

[0079] 1 Reactor 2 Coil, 20 Winding Wire, 21 First End, 22 Second End 251 First Coil Surface, 252 Second Coil Surface 3 Core, 3f First Core, 3s Second Core, 3g Spacing Portion 31 Intermediate Core, 311 First Core Surface, 312 Second Core Surface 31f First Intermediate Core Portion, 31s Second Intermediate Core Portion 32 Side Core, 321 First Core Surface, 322 Second Core Surface 32f First Side Core Portion, 32s Second Side Core Portion 35 First End Core, 351 First Core Surface, 352 Second Core Surface 36 Second End Core, 361 First Core Surface, 362 Second Core Surface D1 First Direction, D2 Second Direction, D3 Third Direction C1 First Outer Peripheral Shape, L11 First Long Side, L12 Second Long Side C2 Second Outer Peripheral Shape, L21 First Long Side, L22 Second Long Side C3 Third Outer Peripheral Shape, L31 First Long Side, L32 Second Long Side C4 Fourth Outer Peripheral Shape, L41 First Long Side, L42 Second Long Side 1100 Power Conversion Device, 1110 Converter 1111 Switching Element, 1112 Drive Circuit 1115 Reactor, 1120 Inverter 1150 Converter for Power Supply Device, 1160 Converter for Auxiliary Power Supply 1200 Vehicle, 1210 Main Battery, 1220 Motor 1230 Sub - Battery, 1240 Auxiliary Equipment 1250 Wheel, 1300 Engine

Claims

1. A reactor, comprising a coil formed by a winding wire wound in a spiral shape, and a core formed so as to pass through the inside and outside of the coil, the number of the coils is one, the core has: a middle core disposed inside the coil; a side core not disposed in the coil and disposed in parallel with the middle core; a first end core connected to the first end of the middle core and the first end of the side core; and a second end core connected to the second end of the middle core and the second end of the side core, the width of the middle core is wider than the width of the side core.

2. The reactor according to claim 1, wherein, The first outer peripheral shape of the coil viewed from a first direction along the axis of the coil is rectangular, the outer peripheral surface of the coil has a first coil surface and a second coil surface that face each other along the long sides of the first outer peripheral shape respectively, the outer peripheral surfaces of the first end core and the second end core each have a first core surface and a second core surface that face each other, the first core surfaces of the first end core and the second end core are substantially coplanar with the first coil surface respectively.

3. The reactor according to claim 2, wherein, the second core surfaces of the first end core and the second end core are substantially coplanar with the second coil surface respectively.

4. The reactor according to claim 2 or claim 3, wherein, the outer peripheral surface of the side core has a first core surface and a second core surface that face each other, the first core surface of the side core is substantially coplanar with the first coil surface.

5. The reactor according to claim 4, wherein, the second core surface of the side core is substantially coplanar with the second coil surface.

6. The reactor according to claim 5, wherein, The first end and the second end of the winding wire are led out in the directions along the long sides respectively.

7. The reactor according to claim 6, wherein, The second outer peripheral shape of the first end core and the second end core viewed from the first direction is rectangular, the first core surfaces and the second core surfaces of the first end core and the second end core are the surfaces along the long sides of the second outer peripheral shape respectively.

8. A converter, comprising the reactor according to any one of claims 1 to 7.

9. A power conversion device, comprising the converter according to claim 8.

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