Reactor, converter, and power conversion device

Abstract

A reactor is provided with a coil and a magnetic core, the magnetic core is provided with a first core and a second core, the first core comprises at least a part of a first end core part and a side core part, the second core comprises a remaining part of a second end core part and the side core part, and at least one of the first core and the second core comprises at least a part of an intermediate core part. The side core portion is arranged in parallel with the middle core portion across the coil, the first core is composed of a molded body of a composite material in which soft magnetic powder is dispersed in resin, the first end core portion has an inner side surface, an outer side surface, and protruding portions provided on the outer side surface, and the protruding portions include a first protruding portion and a second protruding portion. The first protruding portion is provided at a position corresponding to a position between the middle core portion and the first side core portion, and the second protruding portion is provided at a position corresponding to a position between the middle core portion and the second side core portion.

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. 2022-208308 filed on December 26, 2022, and incorporates by reference all the descriptions recorded in the said Japanese application. Background Art

[0002] Among the components of a converter mounted on a vehicle such as a hybrid vehicle, there is a reactor. The reactor includes a coil and a magnetic core. The reactor described in Patent Document 1 Figures 5 to 8 has a magnetic core formed by combining one coil and two magnetic chip pieces. The magnetic core is a so-called E-E core type formed by two E-shaped magnetic chip pieces. The magnetic core is configured in a θ shape by combining the end faces of the two magnetic chip pieces facing each other. The magnetic core has an end core portion, an intermediate core portion, and a side core portion. The end core portion is arranged to face the end face of the coil. The intermediate core portion is arranged inside the coil. The side core portion is arranged in parallel with the intermediate core portion with the coil therebetween. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-201509 Summary of the Invention

[0004] The reactor of the present invention includes a coil and a magnetic core, the coil has a cylindrical shape, and the magnetic core has a θ shape, the coil has a first end face and a second end face, the magnetic core includes a first core and a second core, the first core includes at least a part of a first end core portion and a side core portion, the second core includes a second end core portion and the remaining part of the side core portion, at least one of the first core and the second core includes at least a part of an intermediate core portion, the first end core portion is arranged to face the first end face of the coil, the second end core portion is arranged to face the second end face of the coil, the intermediate core portion is arranged inside the coil, the side core portion has a first side core portion and a second side core portion arranged in parallel with the intermediate core portion with the coil therebetween, the first core is formed of a molded body of a composite material in which soft magnetic powder is dispersed in resin, the first end core portion has: The inner side surface, which is joined to the first ends of the middle core portion, the first side core portion, and the second side core portion respectively; The outer side surface, which faces the side opposite to the inner side surface; and The protrusions, which are provided on the outer side surface, The protrusions include a first protrusion and a second protrusion, The first protrusion is provided at a position corresponding to the portion between the middle core portion and the first side core portion on the outer side surface, The second protrusion is provided at a position corresponding to the portion between the middle core portion and the second side core portion on the outer side surface. Description of the Drawings

[0005] Figure 1 is a schematic perspective view showing the reactor of Embodiment 1. Figure 2 is a schematic top view showing the reactor of Embodiment 1. Figure 3 is Figure 2 a schematic top view showing the main part of the reactor shown enlarged. Figure 4 is a schematic perspective view showing Modification 1 of the reactor of Embodiment 1. Figure 5 is a schematic perspective view showing Modification 2 of the reactor of Embodiment 1. Figure 6 is a schematic top view showing the reactor of Embodiment 2. Figure 7 is showing Figure 6 a schematic top view of half of the reactor shown. Figure 8 is a schematic top view showing the modification of the reactor of Embodiment 2. Figure 9 is showing Figure 8 a schematic top view of half of the reactor shown. Figure 10 is a schematic diagram showing the configuration of the power supply system of a hybrid vehicle. Figure 11 is a circuit diagram schematically showing a power conversion device including a converter. Detailed Description of the Invention

[0006] [Problems to be Solved by the Invention] It is desired to reduce the coil loss caused by the leakage magnetic flux from the magnetic core.

[0007] One object of the present invention is to provide a reactor capable of reducing coil loss.

[0008] [Effects of the Invention] The reactor of the present invention can reduce coil losses.

[0009] [Description of the Embodiment of the Present Invention] First, embodiments of the present invention will be described by way of example.

[0010] (1) The reactor of the present invention includes a coil and a magnetic core. The coil has a cylindrical shape, and the magnetic core has a θ shape. The coil has a first end face and a second end face. The magnetic core includes a first core and a second core. The first core includes at least a part of a first end core portion and a side core portion. The second core includes a second end core portion and the remaining part of the side core portion. At least one of the first core and the second core includes at least a part of an intermediate core portion. The first end core portion is arranged to face the first end face of the coil. The second end core portion is arranged to face the second end face of the coil. The intermediate core portion is arranged inside the coil. The side core portion has a first side core portion and a second side core portion that are arranged side by side with the intermediate core portion with the coil therebetween. The first core is formed of a molded body of a composite material in which soft magnetic powder is dispersed in resin. The first end core portion has: An inner side surface that is joined to the first ends of the intermediate core portion, the first side core portion, and the second side core portion respectively; An outer side surface that faces the side opposite to the inner side surface; and A protrusion that is provided on the outer side surface. The protrusion includes a first protrusion and a second protrusion. The first protrusion is provided at a position on the outer side surface corresponding to the position between the intermediate core portion and the first side core portion. The second protrusion is provided at a position on the outer side surface corresponding to the position between the intermediate core portion and the second side core portion.

[0011] The reactor of the present invention can reduce the coil loss. Generally speaking, the relative magnetic permeability of the formed body of the composite material is low. Therefore, when the first core is composed of the formed body of the composite material, leakage magnetic flux is likely to be generated from the first end core portion. The leakage magnetic flux links with the coil, thereby causing loss in the coil. According to the reactor of the present invention, by providing a protruding portion on the outer side surface of the first end core portion, the magnetic path area of the first end core portion becomes larger. Since it is not easy to generate leakage magnetic flux from the first end core portion, the leakage magnetic flux linking with the coil can be suppressed. As a result of the reduction of the leakage magnetic flux to the coil, the coil loss can be reduced. In particular, by providing the first protruding portion and the second protruding portion at specific positions on the outer side surface of the first end core portion, the leakage magnetic flux from the first end core portion to the coil can be effectively suppressed, and thus the coil loss can be effectively reduced.

[0012] (2) In the reactor described in the above (1), it may also be that The length of the first protruding portion and the length of the second protruding portion are respectively 0.05 times or more and 0.5 times or less of the length of the first end core portion.

[0013] The structure in the above (2) can suppress the increase in the volume of the first core and can effectively reduce the coil loss. By the length of each protruding portion being 0.05 times or more of the length of the first end core portion, the leakage magnetic flux from the first end core portion to the coil can be effectively suppressed. By the length of each protruding portion being 0.5 times or less of the length of the first end core portion, the increase in the volume of the first end core portion can be suppressed.

[0014] (3) In the reactor described in the above (1) or (2), it may also be that The width of the first protruding portion is 0.2 times or more and 1.0 times or less of the interval between the intermediate core portion and the first side core portion, The width of the second protruding portion is 0.2 times or more and 1.0 times or less of the interval between the intermediate core portion and the second side core portion.

[0015] The structure in the above (3) can suppress the increase in the volume of the first core and can effectively reduce the coil loss. By the width of each protruding portion being 0.2 times or more of the interval between the intermediate core portion and each side core portion, the leakage magnetic flux from the first end core portion to the coil can be effectively suppressed. By the width of each protruding portion being 1.0 times or less of the interval between the intermediate core portion and the side core portion, the increase in the volume of the first end core portion can be suppressed.

[0016] (4) In the reactor described in any one of the above (1) to (3), it may also be that The relative magnetic permeability of the first core is 5 or more and 50 or less.

[0017] The structure in the above (4) can easily obtain a predetermined inductance.

[0018] (5) In the reactor described in any one of (1) to (4) above, it can also be that the intermediate core portion has a first intermediate core portion and a second intermediate core portion, the first intermediate core portion is combined with the first end core portion, the second intermediate core portion is combined with the second end core portion.

[0019] The structure of (5) above can make the magnetic characteristics of the first intermediate core portion and the second intermediate core portion different. Through this structure, the magnetic characteristics of the entire magnetic core can be adjusted.

[0020] (6) In the reactor described in (5) above, it can also be that the intermediate core portion has a gap portion between the first intermediate core portion and the second intermediate core portion.

[0021] The structure of (6) above can adjust the magnetic characteristics of the entire magnetic core through the gap portion.

[0022] (7) In the reactor described in any one of (1) to (6) above, it can also be that the first core includes all of the side core portions, the relative magnetic permeability of the first core is lower than the relative magnetic permeability of the second core, the first side core portion and the second side core portion respectively have a first end combined with the first end core portion and a second end combined with the second end core portion, Regarding the interval between the first side core portion and the coil and the interval between the second side core portion and the coil, the second interval at the second end is greater than the first interval at the first end, the ratio of the first interval to the second interval is 0.32 or more and 0.70 or less.

[0023] The structure of (7) above can further reduce the coil loss. When the relative magnetic permeability of the side core portion is low and the relative magnetic permeability of the second end core portion is high, there may be a leakage magnetic flux that takes a shortcut from the side core portion to the second end core portion in the vicinity of the second end. Through the linking of this leakage magnetic flux with the coil, the coil generates loss. According to the structure of (7) above, by making the second interval at the second end greater than the first interval at the first end, the leakage magnetic flux linked to the coil can be suppressed. Since the leakage magnetic flux to the coil is reduced, the coil loss can be reduced. By making the ratio of the first interval to the second interval 0.70 or less, the leakage magnetic flux to the coil can be sufficiently suppressed, so the coil loss can be effectively reduced. In particular, when the ratio of the first interval to the second interval is 0.32 or more and 0.70 or less, the reduction of the inductance can be suppressed while effectively reducing the coil loss.

[0024] By making the magnetic properties of the first core and the second core different, the magnetic properties of the entire magnetic core can be adjusted. By making the relative magnetic permeability of the first core lower than that of the second core, a predetermined inductance can be easily obtained.

[0025] (8) In the reactor described in (7) above, it may also be that The first side core portion and the second side core portion each have a tapered shape with a width that tapers from the first end toward the second end.

[0026] The structure of (8) above is likely to reduce coil losses.

[0027] (9) In the reactor described in (7) above, it may also be that The first side core portion and the second side core portion each have a stepped shape with a width that tapers from the first end toward the second end.

[0028] The structure of (9) above is likely to reduce coil losses.

[0029] (10) In the reactor described in any one of (1) to (9) above, it may also be that The relative magnetic permeability of the second core is 100 or more and 500 or less.

[0030] The structure of (10) above is likely to obtain a predetermined inductance.

[0031] (11) In the reactor described in any one of (1) to (10) above, it may also be that The second core is composed of a compacted powder compact.

[0032] Generally, the relative magnetic permeability of a compacted powder compact is high. The structure of (11) above is likely to form a magnetic core in which the relative magnetic permeability of the first core is lower than that of the second core. By making the second core composed of a compacted powder compact, it is easy to adjust the relative magnetic permeability of the second core to, for example, 100 or more and 500 or less.

[0033] (12) The converter of the present invention Includes the reactor described in any one of (1) to (11) above.

[0034] The converter of the present invention has small losses because it includes the reactor of the present invention.

[0035] (13) The power conversion device of the present invention Includes the converter described in (12) above.

[0036] The power conversion device of the present invention has small losses because it includes the converter of the present invention.

[0037] [Details of the Embodiment of the Present Invention] Hereinafter, specific examples of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings denote the same objects. In addition, 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.

[0038] [Embodiment 1] 〔Reactor〕 Refer to Figures 1 to 3 to describe the reactor 1a of Embodiment 1. The reactor 1a includes a coil 2 and a magnetic core 3. The magnetic core 3 includes a first core 3a and a second core 3b. As Figure 2 shown, the magnetic core 3 is formed by combining the first core 3a and the second core 3b. The magnetic core 3 is formed in a θ shape by an intermediate core portion 31, side core portions 33, and end core portions 35. Figure 1 is a perspective view of the reactor 1a viewed from above. Figure 2 is a top view of the reactor 1a viewed from above. Figure 3 is to Figure 2 a partial top view showing an enlarged view of the vicinity of the first end core portion 35a in the reactor 1a shown.

[0039] The reactor 1a of Embodiment 1 is characterized by satisfying the following requirements (a) and (b). (a) The first core 3a is formed of a molded body of a composite material. (b) A protrusion 40 is provided on the outer side surface 352a of the first end core portion 35a of the first core 3a.

[0040] By providing the protrusion 40 on the outer side surface 352a of the first end core portion 35a, the reactor 1a can reduce the loss of the coil 2. In particular, by providing the protrusion 40 at a specific portion of the outer side surface 352a of the first end core portion 35a, the loss of the coil 2 can be effectively reduced. Hereinafter, the structure of the reactor 1a will be described in detail.

[0041] <Coil> As Figure 1 and Figure 2 shown, the coil 2 is disposed in the intermediate core portion 31 of the magnetic core 3. The coil 2 has a cylindrical shape. The coil 2 has a first end face 2a and a second end face 2b. In the present embodiment, the coil 2 is a flat and upright coil formed by flat and upright winding of a flat wire.

[0042] The shape of the coil 2 can be either a polygonal tubular shape or a cylindrical shape. The so-called polygonal tubular shape means that the contour shape of the end face of the coil 2 is a polygon. The polygon is, for example, a quadrilateral, a hexagon, or an octagon. The quadrilateral includes a rectangle. The rectangle includes a square. The quadrilateral is not limited to a geometric quadrilateral, but includes a shape formed by connecting four corner portions. That is, it also includes a shape in which the four corner portions are rounded by chamfering, or a shape in which the four corner portions are chamfered into a linear shape, etc., in which the fine parts are modified. The same applies to the shape of the protruding portion 40 described later. The so-called cylindrical shape means that the contour shape of the end face of the coil 2 is a circle. The circle includes not only a perfect circle shape but also an elliptical shape. In the present embodiment, the shape of the coil 2 is a rectangular tubular shape.

[0043] <Magnetic core> As Figure 1 and Figure 2 shown, the magnetic core 3 has a middle core portion 31, side core portions 33, and end core portions 35. In Figure 2 and Figure 3 , the boundaries between the middle core portion 31 and the end core portions 35 and between the side core portions 33 and the end core portions 35 are indicated by double-dashed lines. The same applies to the following Figures 6 to 9 . As Figure 2 shown, the magnetic core 3 has a θ-shaped shape when viewed from above.

[0044] In the following description, the X-axis direction, the Y-axis direction, and the Z-axis direction are defined as follows. The X-axis direction is the direction along the axis of the coil 2, and is the direction from the first end face 2a toward the second end face 2b. The Y-axis direction is the direction in which the middle core portion 31 and the side core portions 33 are juxtaposed, and is the direction from the middle core portion 31 toward the side core portions 33. The Y-axis direction is orthogonal to the X-axis direction. The direction from the middle core portion 31 toward the first side core portion 331 is defined as the Y1 direction. The direction from the middle core portion 31 toward the second side core portion 332 is defined as the Y2 direction. The Z-axis direction is orthogonal to both the X-axis direction and the Y-axis direction. When the XY plane including the X-axis and the Y-axis is set to be horizontal, the Z-axis direction is the direction from bottom to top.

[0045] The magnetic core 3 forms a θ-shaped closed magnetic circuit. When the coil 2 is energized, magnetic flux flows into the magnetic core 3. The magnetic flux generated by the coil 2 flows in such a way as to return from the middle core portion 31 via the end core portions 35 and the side core portions 33 to the middle core portion 31. Figure 2 The dashed arrows in Figure 6 and Figure 8 indicate the flow of magnetic flux. The same applies to the following

[0046] (Middle core portion) As Figure 2As shown, the intermediate core portion 31 is disposed within the coil 2. The number of the intermediate core portions 31 is one. The intermediate core portion 31 extends in the X-axis direction. The direction along the length of the intermediate core portion 31 is the same as the direction along the axis of the coil 2. The length of the intermediate core portion 31 is the same as or greater than the length of the coil 2. The length mentioned here refers to the distance along the X-axis direction. The both end portions of the intermediate core portion 31 may protrude from the both end faces of the coil 2. The protruding portions are also part of the intermediate core portion 31. The shape of the intermediate core portion 31 is a shape corresponding to the inner shape of the coil 2. In the present embodiment, the shape of the intermediate core portion 31 is substantially rectangular parallelepiped shape.

[0047] The intermediate core portion 31 is disposed between the first end core portion 35a and the second end core portion 35b. The first end core portion 35a and the second end core portion 35b will be described later. The intermediate core portion 31 has a first end 32a and a second end 32b. The first end 32a is joined to the first end core portion 35a. The second end 32b is joined to the second end core portion 35b.

[0048] In the present embodiment, the intermediate core portion 31 has a first intermediate core portion 31a and a second intermediate core portion 31b. The first intermediate core portion 31a and the second intermediate core portion 31b are arranged in series in the X-axis direction. The boundary between the first intermediate core portion 31a and the second intermediate core portion 31b is located within the coil 2. The first intermediate core portion 31a includes the first end 32a joined to the first end core portion 35a. The second intermediate core portion 31b includes the second end 32b joined to the second end core portion 35b. The term "joined" means sticking together without separation. The first intermediate core portion 31a and the first end core portion 35a may be integrally formed. In the case where the first intermediate core portion 31a and the first end core portion 35a are respectively independent separate components, for example, the first end 32a may be bonded to the first end core portion 35a, and they may also be integrated by being covered with a resin molded part at least in part of the first intermediate core portion 31a and the first end core portion 35a. The second intermediate core portion 31b and the second end core portion 35b may be integrally formed. In the case where the second intermediate core portion 31b and the second end core portion 35b are respectively independent separate components, for example, the second end 32b may be bonded to the second end core portion 35b, and they may also be integrated by being covered with a resin molded part at least in part of the second intermediate core portion 31b and the second end core portion 35b. The resin molded part is a formed member formed in a series so as to cover at least part of each of the first core 3a and the second core 3b. In the present embodiment, the first intermediate core portion 31a and the first end core portion 35a are integrally formed. The second intermediate core portion 31b and the second end core portion 35b are integrally formed.

[0049] The lengths of the first intermediate core portion 31a and the second intermediate core portion 31b can be appropriately set. In the present embodiment, the length of the first intermediate core portion 31a is different from the length of the second intermediate core portion 31b. The first intermediate core portion 31a is longer than the second intermediate core portion 31b. The first intermediate core portion 31a may also be shorter than the second intermediate core portion 31b. The lengths of the first intermediate core portion 31a and the second intermediate core portion 31b may also be the same.

[0050] In the present embodiment, the intermediate core portion 31 has a gap portion 31g. The gap portion 31g is provided between the first intermediate core portion 31a and the second intermediate core portion 31b. By the intermediate core portion 31 having the gap portion 31g, the inductance can be adjusted. The gap portion 31g is located inside the coil 2. When the gap portion 31g is located inside the coil 2, compared with the case where the gap portion 31g is exposed from the coil 2, the leakage magnetic flux from the gap portion 31g is reduced. Therefore, it is easy to suppress the linkage of the leakage magnetic flux from the gap portion 31g with the coil 2. The loss caused by the leakage magnetic flux from the gap portion 31g can be reduced. The length of the gap portion 31g is appropriately set to obtain a predetermined inductance. The length of the gap portion 31g is, for example, 0.1 mm or more and 3 mm or less, 0.3 mm or more and 2.5 mm or less, and further 0.5 mm or more and 2 mm or less. The gap portion 31g may also be an air gap. The gap portion 31g may also be made of a non-magnetic material, and the non-magnetic material is made of resin or ceramic. When the intermediate core portion 31 has the gap portion 31g, the length of the intermediate core portion 31 is the total length of the length of the first intermediate core portion 31a, the length of the second intermediate core portion 31b, and the length of the gap portion 31g. There may also be no gap portion 31g. When there is no gap portion 31g, the first intermediate core portion 31a and the second intermediate core portion 31b are in contact with each other, and there is substantially no gap between the first intermediate core portion 31a and the second intermediate core portion 31b.

[0051] (Side core portion) As Figure 2 shown, the side core portions 33 are arranged outside the coil 2. The side core portions 33 are arranged in parallel with the intermediate core portion 31 with the coil 2 therebetween. The inner side surface of the side core portion 33 faces the outer peripheral surface of the coil 2. The number of the side core portions 33 is two. The side core portions 33 extend in the X-axis direction. The direction along the length of the side core portion 33 is parallel to the direction along the length of the intermediate core portion 31. The length of the side core portion 33 is equal to the length of the intermediate core portion 31.

[0052] The side core part 33 has a first side core part 331 and a second side core part 332. The first side core part 331 and the second side core part 332 are arranged at intervals in the Y-axis direction. The first side core part 331 is arranged to be away from the middle core part 31 in the Y1 direction. The second side core part 332 is arranged to be away from the middle core part 31 in the Y2 direction. In the present embodiment, the first side core part 331 and the second side core part 332 are arranged symmetrically with respect to the center line of the middle core part 31.

[0053] The first side core part 331 and the second side core part 332 are arranged between the first end core part 35a and the second end core part 35b. The first side core part 331 and the second side core part 332 respectively have a first end 34a and a second end 34b. The first end 34a is combined with the first end core part 35a. The second end 34b is combined with the second end core part 35b. The first side core part 331 and the second side core part 332 only need to have a length connecting the first end core part 35a and the second end core part 35b respectively. The shapes of the first side core part 331 and the second side core part 332 can also be any shape. In the present embodiment, the shapes of the first side core part 331 and the second side core part 332 are both substantially rectangular parallelepiped shapes. The shape of the first side core part 331 and the shape of the second side core part 332 are symmetric with respect to the center line of the middle core part 31.

[0054] In the present embodiment, the side core part 33 and the first end core part 35a are integrally formed. The side core part 33 and the first end core part 35a can also be independent separate components. In this case, for example, the first end 34a can be bonded to the first end core part 35a, and they can also be integrated by at least a part of the side core part 33 and the first end core part 35a being covered by a resin molding. In the present embodiment, the side core part 33 and the second end core part 35b are independent separate components. The side core part 33 and the second end core part 35b are integrated by a resin molding (not shown). The second end 34b of the side core part 33 can also be bonded to the second end core part 35b.

[0055] (End core part) As Figure 2 shown, the end core part 35 is arranged outside the coil 2. The end core part 35 is arranged to face the two end faces of the coil 2 respectively. The number of the end core parts 35 is two. The end core part 35 has a first end core part 35a and a second end core part 35b. The first end core part 35a faces the first end face 2a of the coil 2. The second end core part 35b faces the second end face 2b of the coil 2. The first end core part 35a and the second end core part 35b are arranged at intervals in the X-axis direction.

[0056] The first end core portion 35a has an inner side surface 351a and an outer side surface 352a. The second end core portion 35b has an inner side surface 351b and an outer side surface 352b. The inner side surface 351a of the first end core portion 35a and the inner side surface 351b of the second end core portion 35b face each other. The first end 32a of the intermediate core portion 31 and the first ends 34a of the first side core portion 331 and the second side core portion 332 are joined to the inner side surface 351a of the first end core portion 35a. The outer side surface 352a of the first end core portion 35a is a surface facing the side opposite to the inner side surface 351a. That is, the outer side surface 352a is a surface facing away from the first end 32a and the first ends 34a. The second end 32b of the intermediate core portion 31 and the second ends 34b of the first side core portion 331 and the second side core portion 332 are joined to the inner side surface 351b of the second end core portion 35b. The outer side surface 352b of the second end core portion 35b is a surface facing the side opposite to the inner side surface 351b. That is, the outer side surface 352b is a surface facing away from the second end 32b and the second ends 34b.

[0057] <Protrusion> In the present embodiment, the first end core portion 35a has a protrusion 40. The protrusion 40 is provided on the outer side surface 352a of the first end core portion 35a. The protrusion 40 protrudes in a direction away from the inner side surface 351a. As Figure 1 shown, the protrusion 40 extends from the upper edge to the lower edge of the outer side surface 352a in the Z-axis direction. That is, the protrusion 40 is provided over the entire height of the first end core portion 35a.

[0058] In the present embodiment, as Figure 2As shown, the number of protrusions 40 is two. The protrusions 40 include a first protrusion 41 and a second protrusion 42. The first protrusion 41 is provided at a position corresponding to between the intermediate core 31 and the first side core 331 on the outer side surface 352a. The position corresponding to between the intermediate core 31 and the first side core 331 on the outer side surface 352a means a region sandwiched by a virtual line obtained by extending the outer peripheral surface of the first end 32a of the intermediate core 31 in the X-axis direction and a virtual line obtained by extending the inner side surface of the first end 34a of the first side core 331 in the X-axis direction when viewed from above. The first protrusion 41 is located within this region. Hereinafter, this region will be referred to as the first outer region. The second protrusion 42 is provided at a position corresponding to between the intermediate core 31 and the second side core 332 on the outer side surface 352a. The position corresponding to between the intermediate core 31 and the second side core 332 on the outer side surface 352a means a region sandwiched by a virtual line obtained by extending the outer peripheral surface of the first end 32a of the intermediate core 31 in the X-axis direction and a virtual line obtained by extending the inner side surface of the first end 34a of the second side core 332 in the X-axis direction when viewed from above. The second protrusion 42 is located within this region. Hereinafter, this region will be referred to as the second outer region. In the present embodiment, the first protrusion 41 and the second protrusion 42 are symmetrically arranged with respect to the center line of the intermediate core 31.

[0059] By having the protrusion 40 on the first end core 35a, leakage magnetic flux from the first end core 35a to the coil 2 can be suppressed. Since the leakage magnetic flux from the first end core 35a to the coil 2 is reduced, the loss of the coil 2 can be lowered. In particular, when the first protrusion 41 and the second protrusion 42 are provided at specific positions on the outer side surface 352a of the first end core 35a, leakage magnetic flux from the first end core 35a to the coil 2 can be effectively suppressed, and thus the loss of the coil 2 can be effectively reduced.

[0060] <Material of the protrusion> The protrusion 40 is made of a soft magnetic material. The protrusion 40 can be integrally formed with the first end core 35a, and can also be a separate component independent of the first end core 35a. When the protrusion 40 and the first end core 35a are integrally formed, the protrusion 40 and the first end core 35a are of the same material. When the protrusion 40 and the first end core 35a are separate components, the material of the protrusion 40 can be, for example, a formed body of a composite material, a powder compact, or a plate of a soft magnetic metal. The soft magnetic metal is, for example, iron. When the protrusion 40 and the first end core 35a are separate components, the protrusion 40 can be bonded to the outer side surface 352a of the first end core 35a, and can also be integrated by a resin molding. In the present embodiment, the protrusion 40 is integrally formed with the first end core 35a.

[0061] <Shape of the protrusion> The shape of the protruding portion 40 can also be any shape. The shape of the protruding portion 40 mentioned here refers to the shape when viewed from above. The shape of the protruding portion 40 is, for example, a polygon or an arc shape. The polygon is, for example, a triangle, a quadrilateral, a pentagon, or a hexagon. The quadrilateral includes, for example, a rectangle and a trapezoid. The rectangle includes a square. The corner portions of the protruding portion 40 can also be chamfered. The arc shape is a shape having an arc. The arc shape includes, for example, a semi - circle and a semi - ellipse. The shape of the first protruding portion 41 and the shape of the second protruding portion 42 can be the same or different. In the present embodiment, the shapes of the first protruding portion 41 and the second protruding portion 42 are each a rectangle.

[0062] Refer to Figure 3 to describe the length and width of the protruding portion 40. Figure 3 Show Figure 2 The part of the first end core portion 35a including the first core 3a in the reactor 1a shown.

[0063] <Length of the protruding portion> The lengths of the first protruding portion 41 and the second protruding portion 42 are each, for example, 0.05 times or more and 0.5 times or less the length of the first end core portion 35a. That is, the ratio of the length L40 of the protruding portion 40 to the length L35 of the first end core portion 35a is 0.05 or more and 0.5 or less. The ratio of the length L40 to the length L35 is expressed as L40 / L35. The length mentioned here refers to the distance along the X - axis direction. The length L35 of the first end core portion 35a corresponds to the distance from the inner side surface 351a to the outer side surface 352a of the portion of the first end 32a where the intermediate core 31 is joined. The length L40 of the protruding portion 40 corresponds to the distance from the imaginary plane obtained by extending the outer side surface 352a of the portion of the first end 32a where the intermediate core 31 is joined in the Y - axis direction to the tip of the protruding portion 40. The length L40 is equal to the difference between the distance from the inner side surface 351a to the tip of the protruding portion 40 and the length L35 of the first end core portion 35a.

[0064] By the length L40 being 0.05 times or more the length L35, that is, the ratio L40 / L35 being 0.05 or more, the leakage magnetic flux from the first end core portion 35a to the coil 2 can be effectively suppressed. From the viewpoint of suppressing the leakage magnetic flux, the ratio L40 / L35 can further be 0.1 or more, 0.2 or more. By the length L40 being 0.5 times or less the length L35, that is, the ratio L40 / L35 being 0.5 or less, an increase in the volume of the first end core portion 35a can be suppressed. The ratio L40 / L35 can also be, for example, 0.1 or more and 0.5 or less, 0.2 or more and 0.5 or less.

[0065] <Width of the protruding portion> The width of the first protruding portion 41 is, for example, 0.2 times or more and 1.0 times or less of the interval D33 between the intermediate core portion 31 and the first side core portion 331. The width of the second protruding portion 42 is, for example, 0.2 times or more and 1.0 times or less of the interval between the intermediate core portion 31 and the second side core portion 332. That is, the ratio of the width W40 of the protruding portion 40 to the interval D33 between the intermediate core portion 31 and the side core portion 33 is 0.2 or more and 1.0 or less. The ratio of the width W40 to the interval D33 is expressed as W40 / D33. The so-called interval D33 refers to the interval between the outer peripheral surface of the intermediate core portion 31 and the inner side surface of the side core portion 33. The interval D33 is the interval between the first end 32a of the intermediate core portion 31 and the first end 34a of the side core portion 33. The interval D33 is equal to the width of each of the first outer region and the second outer region of the outer side surface 352a described above. The width mentioned here refers to the distance along the Y-axis direction. The width W40 of the protruding portion 40 is the distance along the Y-axis direction. The width W40 corresponds to the maximum distance between the side surface of the protruding portion 40 facing the Y1 direction and the side surface facing the Y2 direction. The width W40 is equal to the interval between two lines parallel to the X-axis when the protruding portion 40 is sandwiched by the two lines.

[0066] By making the width W40 0.2 times or more of the interval D33, that is, by making the ratio W40 / D33 0.2 or more, the leakage magnetic flux from the first end core portion 35a to the coil 2 can be effectively suppressed. From the viewpoint of suppressing the leakage magnetic flux, the ratio W40 / D33 can further be 0.3 or more, 0.4 or more. By making the width W40 1.0 times or less of the interval D33, that is, by making the ratio W40 / D33 1.0 or less, an increase in the volume of the first end core portion 35a can be suppressed. The ratio W40 / D33 can also be, for example, 0.3 or more and 1.0 or less, 0.4 or more and 1.0 or less. Figure 3 An example of the ratio W40 / D33 in [] is 1.0.

[0067] As Figure 4 and Figure 5 shown, the protruding portion 40 can also be provided in a part of the height of the first end core portion 35a. For example, as Figure 4 shown in Modification 1, the protruding portion 40 can also be provided in multiple parts in the Z-axis direction. In Modification 1, the protruding portion 40 is respectively arranged in the part near the upper edge and the part near the lower edge of the outer side surface 352a. For example, as Figure 5 shown in Modification 2, the protruding portion 40 can also be arranged only in the central part of the outer side surface 352a. When the protruding portion 40 is provided in a part of the height of the first end core portion 35a, the protruding portion 40 is provided, for example, in a range of 1 / 2 or more of the height of the first end core portion 35a. In Figure 4In the first modification example shown, the portion of the outer side surface 352a near the upper edge is a region of 1 / 4 starting from the upper edge after equally dividing the outer side surface 352a in the Z-axis direction. The portion of the outer side surface 352a near the lower edge is a region of 1 / 4 starting from the lower edge after equally dividing the outer side surface 352a in the Z-axis direction. In Figure 5 In the second modification example shown, the central portion of the outer side surface 352a is a region of 1 / 2 of the center after equally dividing the outer side surface 352a in the Z-axis direction. The volume of the protruding portion 40 in the first modification example is the same as the volume of the protruding portion 40 in the second modification example.

[0068] (First core · Second core) As Figure 2 shown, the magnetic core 3 is composed of a first core 3a and a second core 3b. In the present embodiment, the first core 3a has an E-shaped configuration, and the second core 3b has a T-shaped configuration. That is, the magnetic core 3 is an E-T type composed of the E-shaped first core 3a and the T-shaped second core 3b.

[0069] (First core) The first core 3a includes at least a part of the first end core portion 35a and the side core portion 33. In the present embodiment, the first core 3a has a first end core portion 35a, a first intermediate core portion 31a, a first side core portion 331, and a second side core portion 332. That is, the first core 3a has the entire side core portion 33. The first intermediate core portion 31a, the first end core portion 35a, the first side core portion 331, and the second side core portion 332 are integrally formed. Since the first core 3a is an integrally formed product, the core portions constituting the first core 3a are of the same material. That is, the magnetic characteristics of the core portions constituting the first core 3a are substantially the same. The shape of the first core 3a is E-shaped in a plan view.

[0070] (Second core) The second core 3b includes the second end core portion 35b and the remaining portion of the side core portion 33. In the present embodiment, the second core 3b has a second end core portion 35b and a second intermediate core portion 31b. The second end core portion 35b and the second intermediate core portion 31b are integrally formed. Since the second core 3b is an integrally formed product, the core portions constituting the second core 3b are of the same material. That is, the magnetic characteristics of the core portions constituting the second core 3b are substantially the same. The shape of the second core 3b is T-shaped in a plan view.

[0071] At least one of the first core 3a and the second core 3b includes at least a part of the intermediate core portion 31. The first core 3a may also have the entire intermediate core portion 31. When the first core 3a has the entire intermediate core portion 31, the second core 3b only has the second end core portion 35b. In this case, the shape of the second core 3b is I-shaped when viewed from above. The second core 3b may also have the entire intermediate core portion 31. When the second core 3b has the entire intermediate core portion 31, the first core 3a is composed of the first end core portion 35a, the first side core portion 331, and the second side core portion 332. In this case, the shape of the first core 3a is U-shaped when viewed from above.

[0072] The side core portion 33 may also be divided in the X-axis direction. In this case, the first side core portion 331 and the second side core portion 332 each have a first part including the first end 34a and a second part including the second end 34b. It may also be configured that the first core 3a has the first part of each of the first side core portion 331 and the second side core portion 332, and the second core 3b has the second part of each of the first side core portion 331 and the second side core portion 332. In this case, the shape of each of the first core 3a and the second core 3b is E-shaped when viewed from above.

[0073] <First core · Second relative permeability> The relative permeability of the first core 3a is lower than the relative permeability of the second core 3b. That is, in the magnetic core 3, the relative permeability of the side core portion 33 is lower than the relative permeability of the second end core portion 35b. The relative permeabilities of the first core 3a and the second core 3b are appropriately set on the basis of satisfying the above relationship to obtain a predetermined inductance. The relative permeability of the first core 3a is, for example, 5 or more and 50 or less. The relative permeability of the second core 3b is, for example, 50 or more and 500 or less. If the relative permeability of the first core 3a is in the range of 5 or more and 50 or less, and the relative permeability of the second core 3b is in the range of 50 or more and 500 or less, it is easy to obtain a predetermined inductance. The relative permeability of the first core 3a may also be 10 or more and 45 or less, and further 15 or more and 40 or less. The relative permeability of the second core 3b may also be 100 or more and 450 or less, and further 150 or more and 400 or less. The difference between the relative permeability of the first core 3a and the relative permeability of the second core 3b is, for example, 50 or more. The difference between the relative permeability of the first core 3a and the relative permeability of the second core 3b may also be 50 or more and 450 or less, and further 100 or more and 400 or less.

[0074] The relative permeability can be obtained as follows. Ring-shaped measurement specimens are cut out from the first core 3a and the second core 3b respectively. Windings are applied to each measurement specimen with 300 turns on the primary side and 20 turns on the secondary side. The B-H initial magnetization curve is measured in the range from H = 0 (Oe) to 100 (Oe), and the maximum value of B / H of the B-H initial magnetization curve is obtained. This maximum value is taken as the relative permeability. The magnetization curve mentioned here is the so-called DC magnetization curve.

[0075] <Material of the first core and the second core> The first core 3a and the second core 3b are each composed of a formed body of a soft magnetic material. The formed body is, for example, a compacted powder formed body or a formed body of a composite material. The first core 3a and the second core 3b are composed of formed bodies of mutually different materials. By mutually different materials, it goes without saying that in each formed body constituting the first core 3a and the second core 3b, the materials of the respective constituent elements are different, and it also includes cases where even though the materials of the respective constituent elements are the same, the contents of the constituent elements are different. For example, even if the first core 3a and the second core 3b are composed of compacted powder formed bodies, if at least one of the material and content of the soft magnetic powder constituting the compacted powder formed body is different, they are also mutually different materials. In addition, even if the first core 3a and the second core 3b are composed of formed bodies of composite materials, if at least one of the material and content of the soft magnetic powder constituting the composite material is different, they are also mutually different materials.

[0076] The compacted powder formed body is formed by compression molding of raw powder containing soft magnetic powder. Compared with the formed body of the composite material, the content of the soft magnetic powder is more in the compacted powder formed body. Therefore, compared with the formed body of the composite material, the magnetic properties are higher. The magnetic properties are, for example, relative permeability and saturation magnetic flux density. The compacted powder formed body may also contain, for example, at least one of an adhesive resin and a forming aid. When the compacted powder formed body is set to 100% by volume, the content of the soft magnetic powder in the compacted powder formed body is, for example, 85% by volume or more and 99.99% by volume or less.

[0077] The formed body of the composite material is formed by dispersing soft magnetic powder in resin. The formed body of the composite material is obtained by filling a fluid raw material in which soft magnetic powder is dispersed in uncured resin into a mold and curing the resin. The formed body of the composite material can easily adjust the content of the soft magnetic powder. Therefore, the magnetic properties of the formed body of the composite material can be easily adjusted. When the formed body of the composite material is set to 100% by volume, 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.

[0078] The particles constituting the soft magnetic powder are at least one selected from the group consisting of soft magnetic metal particles, coated particles having an insulating coating portion on the outer periphery of the soft magnetic metal particles, and soft magnetic non-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 (iron)-Si (silicon) alloy or an Fe-Ni (nickel) alloy. The insulating coating portion is, for example, phosphate. The soft magnetic non-metal is, for example, ferrite.

[0079] In the present embodiment, the first core 3a is formed of a formed body of a composite material. The second core 3b is formed of a compacted powder formed body. By forming the first core 3a of a formed body of a composite material and the second core 3b of a compacted powder formed body, the magnetic characteristics of the entire magnetic core 3 can be adjusted. Further, when the first core 3a is formed of a formed body of a composite material, the relative magnetic permeability of the first core 3a easily satisfies 5 or more and 50 or less. When the second core 3b is formed of a compacted powder formed body, the relative magnetic permeability of the second core 3b easily satisfies 100 or more and 500 or less.

[0080] [Embodiment 2] Refer to Figure 6 and Figure 7 The reactor 1b of Embodiment 2 will be described. In the reactor 1b of Embodiment 2, regarding the interval between the side core portion 33 and the coil 2, the second interval at the second end 34b is larger than the first interval at the first end 34a, which is different from the reactor 1a of Embodiment 1. The following description will focus on the differences from Embodiment 1. The same reference numerals are given to the same structures as those in Embodiment 1, and the description thereof will be omitted.

[0081] In the reactor 1b of Embodiment 2, the first end core portion 35a has a protrusion 40 and satisfies the following requirements (c) and (d). (c) The relative magnetic permeability of the first core 3a is lower than that of the second core 3b. (d) As Figure 7 shown, the second interval D2 is larger than the first interval D1, and the ratio D1 / D2 of the first interval D1 to the second interval D2 is 0.32 or more and 0.70 or less.

[0082] In the reactor 1b, by making the second interval D2 larger than the first interval D1, the loss of the coil 2 can be further reduced. In particular, by making the ratio D1 / D2 of the first interval D1 to the second interval D2 0.32 or more and 0.70 or less, a decrease in inductance can be suppressed, and at the same time, the loss of the coil 2 can be effectively reduced.

[0083] <Interval between side core portion and coil> In the present embodiment, the intervals between the first side core portion 331 and the coil 2 and between the second side core portion 332 and the coil 2 are not constant in the X-axis direction, respectively. That is, the intervals between the side core portions 33 and the coil 2 are not constant over the entire length of the side core portions 33. The intervals between the side core portions 33 and the coil 2 increase from the first end 34a toward the second end 34b. The interval between the side core portion 33 and the coil 2 means the interval between the inner side surface of the side core portion 33 and the outer peripheral surface of the coil 2.

[0084] Refer to Figure 7 for a detailed description of the interval between the side core portion 33 and the coil 2. Figure 7 Only the half including the first side core portion 331 in the part obtained by bisecting the reactor 1b shown in Figure 6 with the center line of the intermediate core portion 31 is shown. Here, refer to Figure 7 for a description of the interval between the first side core portion 331 and the coil 2, but the interval between the second side core portion 332 and the coil 2 is the same. Regarding the interval between the first side core portion 331 and the coil 2, the second interval D2 at the second end 34b is greater than the first interval D1 at the first end 34a. The first interval D1 means the interval between the inner side surface of the first side core portion 331 at the first end 34a and the imaginary surface obtained by extending the outer peripheral surface of the coil 2. When the corners of the end face and the inner side surface at the first end 34a are chamfered, it is regarded as not being chamfered. That is, the interval between the corner of the extended surface of the end face and the extended surface of the inner side surface at the first end 34a and the above-mentioned imaginary surface is regarded as the first interval D1. The second interval D2 means the interval between the inner side surface of the first side core portion 331 at the second end 34b and the imaginary surface obtained by extending the outer peripheral surface of the coil 2. When the corners of the end face and the inner side surface at the second end 34b are chamfered, it is regarded as not being chamfered. That is, the interval between the corner of the extended surface of the end face and the extended surface of the inner side surface at the second end 34b and the above-mentioned imaginary surface is regarded as the second interval D2.

[0085] The ratio of the first interval D1 to the second interval D2 is 0.32 or more and 0.70 or less. The ratio of the first interval D1 to the second interval D2 is expressed as D1 / D2. The smaller the ratio D1 / D2, the larger the second interval D2. The larger the second interval D2, the larger the interval between the side core portion 33 and the coil 2 in the vicinity of the second end 34b. Therefore, it is possible to suppress the leakage magnetic flux that takes a short cut from the side core portion 33 toward the second end core portion 35b from linking with the coil 2 in the vicinity of the second end 34b. Since the leakage magnetic flux to the coil 2 is reduced, the loss of the coil 2 can be reduced. By setting the ratio D1 / D2 to 0.70 or less, the leakage magnetic flux to the coil 2 can be sufficiently suppressed, so that the loss of the coil 2 can be effectively reduced. When the ratio D1 / D2 becomes too small, that is, when the second interval D2 becomes too large, the inductance may decrease, and it may be difficult to obtain a predetermined inductance. By setting the ratio D1 / D2 to 0.32 or more, it is easy to suppress the decrease in inductance. The ratio D1 / D2 can further be 0.35 or more and 0.70 or less, 0.40 or more and 0.60 or less.

[0086] In Figure 6 the above, the interval D33 between the intermediate core portion 31 and the first side core portion 331 (refer to Figure 3 ) is the interval between the outer peripheral surface of the first end 32a of the intermediate core portion 31 and the inner side surface of the first end 34a of the side core portion 33.

[0087] <Shape of the side core portion> The side core portion 33 has a shape in which the width of the side core portion 33 tapers from the first end 34a toward the second end 34b. The side core portion 33 only needs to have a width at the second end 34b that is thinner than the width at the first end 34a. The side core portion 33 only needs to have at least a portion with a tapered width between the first end 34a and the second end 34b, and may also have a portion with a constant width between the first end 34a and the second end 34b. The width of the side core portion 33 is the dimension of the side core portion 33 in the Y-axis direction. In the present embodiment, the shapes of the first side core portion 331 and the second side core portion 332 are symmetric with respect to the center line of the intermediate core portion 31.

[0088] Refer to Figure 7, the shape of the side core portion 33 in the present embodiment will be described in detail. Here, the shape of the first side core portion 331 will be described. The first side core portion 331 has a tapered shape. The tapered shape means a shape having a portion that continuously tapers from the first end 34a toward the second end 34b. In the present embodiment, the first side core portion 331 is formed in a tapered shape over its entire length. The inner surface of the first side core portion 331 has an inclined surface 33t that is inclined with respect to the outer peripheral surface of the coil 2. The inclined surface 33t is inclined so as to be away from the outer peripheral surface of the coil 2 from the first end 34a toward the second end 34b. The angle of the inclined surface 33t with respect to the outer peripheral surface of the coil 2 is appropriately set such that the ratio of the first interval D1 to the second interval D2 satisfies a predetermined range. The angle of the inclined surface 33t means the angle formed between the inclined surface 33t and the outer peripheral surface of the coil 2. The outer peripheral surface of the coil 2 is parallel to the X-axis. The angle of the inclined surface 33t can be appropriately set according to the length of the first side core portion 331. The angle of the inclined surface 33t is, for example, 1° or more and less than 5°, and further 2° or more and 4° or less.

[0089] In Figure 8 , the interval D33 between the above-mentioned intermediate core portion 31 and the first side core portion 331 (refer to Figure 3 ) is the interval between the outer peripheral surface of the first end 32a of the intermediate core portion 31 and the inner surface of the first end 34a of the side core portion 33.

[0090] [Modified Example] Refer to Figure 8 and Figure 9 to describe a modified example of the reactor 1b of Embodiment 2. Figure 8 and Figure 9 The shape of the side core portion 33 of the reactor 1b of the modified example shown is a stepped shape.

[0091] Refer to Figure 9, describe in detail the shape of the side core part 33 in the modified example. Here, describe the shape of the first side core part 331. The side core part 33 has a stepped shape. The so-called stepped shape means a shape having a portion where the width gradually tapers from the first end 34a toward the second end 34b. The inner side surface of the first side core part 331 has a stepped portion 33s. In the modified example, the stepped portion 33s is located at the center of the length of the first side core part 331. The first side core part 331 is divided into two regions by one stepped portion 33s. The region from the first end 34a to the stepped portion 33s is the first region 341. The region from the stepped portion 33s to the second end 34b is the second region 342. The width of the second region 342 is thinner than the width of the first region 341. The inner side surfaces of the first region 341 and the second region 342 are respectively parallel to the outer peripheral surface of the coil 2. The interval between the inner side surface of the second region 342 and the outer peripheral surface of the coil 2 is greater than the interval between the inner side surface of the first region 341 and the outer peripheral surface of the coil 2. The width of the stepped portion 33s is appropriately set so that the ratio of the first interval D1 to the second interval D2 satisfies a predetermined range. The width of the stepped portion 33s corresponds to the distance in the Y-axis direction along the stepped portion 33s. The width of the stepped portion 33s is equal to the difference between the distance from the outer peripheral surface of the coil 2 to the inner side surface of the second region 342 and the distance from the outer peripheral surface of the coil 2 to the inner side surface of the first region 341. That is, the width of the stepped portion 33s is represented by D2 - D1. The width of the stepped portion 33s is, for example, 1 mm or more and less than 5 mm, and further 1.25 mm or more and 4 mm or less.

[0092] In the modified example, the number of the stepped portions 33s is one, but there may also be a plurality of stepped portions 33s. When the number of the stepped portions 33s is n, the number of the regions constituting the side core part 33 is n + 1. The (n + 1)-th region is a region closer to the second end 34b than the n-th region, and the width of the (n + 1)-th region is thinner than the width of the n-th region. The width gradually tapers as it goes from the first region toward the (n + 1)-th region.

[0093] The shape of the side core part 33 may also be a shape formed by combining a conical shape and a stepped shape. As a modified example of the shape of the side core part 33, for example, there are the following shapes. (1) In Figure 9 , the first region 341 may be a conical shape, and the second region 342 may be a shape having no stepped portion 33s with respect to the first region 341 and a constant width. (2) In Figure 9 , the first region 341 may be a conical shape, and the second region 342 may be a shape having a stepped portion 33s with respect to the first region 341 and a constant width. (3) In Figure 9In this case, the first region 341 may have a shape with a constant width, and the second region 342 may have a tapered shape without a step portion 33s relative to the first region 341. (4) In Figure 9 this case, the first region 341 may have a shape with a constant width, and the second region 342 may have a step portion 33s and a tapered shape relative to the first region 341.

[0094] [Embodiment 3] [Converter · Power Conversion Device] The reactor of the embodiment can be used for applications that satisfy the following energization conditions. The energization conditions are, for example: 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 of the embodiment can typically be used as a component of a converter mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and as a component of a power conversion device including the converter.

[0095] As Figure 10 shown, vehicles 1200 such as hybrid vehicles and electric vehicles include 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 10 this case, a socket is shown as the charging part of the vehicle 1200, but it can be configured to include a plug.

[0096] The power conversion device 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110 that mutually converts DC and AC. The converter 1110 shown in this example boosts the input voltage of the main battery 1210, which is in the range of 200 V or more and 300 V or less, to a range of 400 V or more and 700 V or less and supplies power to the inverter 1120 during vehicle 1200 driving. The converter 1110 steps down the input voltage output from the electric motor 1220 via the inverter 1120 to a DC voltage suitable for the main battery 1210 to charge 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 electric motor 1220 during vehicle 1200 driving, and converts the AC output from the electric motor 1220 into DC and outputs it to the converter 1110 during regeneration.

[0097] AsFigure 11 As 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 conduction and interruption. The conversion of the input voltage herein is to perform step-up / 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 attempts to impede the change in the current flowing through the circuit, when the current attempts to increase or decrease due to the switching operation, making its change smooth. The reactor of the embodiment is provided as the reactor 1115. By providing the reactor of the embodiment, the losses of the power conversion device 1100 and the converter 1110 are small.

[0098] In addition to the converter 1110, the vehicle 1200 further 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, but the power supply converter 1150 and the auxiliary power supply converter 1160 perform AC-DC conversion. There is also a reactor that performs DC-DC conversion in the power supply converter 1150. Reactors having the same structure as the reactor of the embodiment and appropriately changed in size, shape, etc. can be used in the reactors of the power supply converter 1150 and the auxiliary power supply converter 1160. In addition, the reactor of the embodiment can also be used in a converter that performs conversion of the input power and is only a step-up converter or only a step-down converter.

[0099] <Test Example 1> The inductance and loss of a reactor having the same structure as the reactor 1a of Embodiment 1 were evaluated.

[0100] In Test Example 1, reactors of Specimen Nos. 1-0 to 1-7 shown in Design Table 1 were designed. Specimen Nos. 1-0 to 1-7 are models in which the lengths L40 of the first protrusion 41 and the second protrusion 42 are each changed in the range of 0 mm to 10 mm. Specimen No. 1-0 with the length L40 of the protrusion 40 being 0 mm does not have the first protrusion 41 and the second protrusion 42. The basic structure of the designed reactor is shown below.

[0101] (Dimensions of the magnetic core) · The length L of the magnetic core 3: 80 mm · The width W of the magnetic core 3: 65 mm · The height H of the magnetic core 3: 25 mm AsFigure 1 As shown, the length L is the dimension of the magnetic core 3 in the X-axis direction. The width W is the dimension of the magnetic core 3 in the Y-axis direction. The height H is the dimension of the magnetic core 3 in the Z-axis direction. (Dimensions of each core part) · Length of the middle core part 31: 53.2 mm · Width of the middle core part 31: 25 mm · Lengths of the first side core part 331 and the second side core part 332: 53.2 mm · Widths of the first side core part 331 and the second side core part 332: 9 mm · Lengths of the first end core part 35a and the second end core part 35b: 13.4 mm · Widths of the first end core part 35a and the second end core part 35b: 65 mm · Length of the gap part 31g: 2 mm · Spacing between the middle core part 31 and the first side core part 331: 11 mm · Spacing between the middle core part 31 and the second side core part 332: 11 mm The length of each core part is the dimension in the X-axis direction. The width of each core part is the dimension in the Y-axis direction. The height of each core part, that is, the dimension in the Z-axis direction, is 25 mm.

[0102] Relative permeability of the first core 3a: 20 Relative permeability of the second core 3b: 200

[0103] The lengths L40 of the protrusions 40, the lengths L35 of the first end core part 35a, and the ratio (L40 / L35) of the length L40 to the length L35 in Samples No. 1-0 to No. 1-7 are shown in Table 1. In addition, the width W40 of each of the first protrusion 41 and the second protrusion 42 is 11 mm. The spacing D33 between the middle core part 31 and the side core part 33 is 11 mm. The ratio (W40 / D33) of the width W40 to the spacing D33 is 1.

[0104] The inductance and loss of the reactor for each sample are analyzed. In the analysis of inductance and loss, a commercially available electromagnetic field analysis software, namely JMAG-Designer 21.0 manufactured by JSOL Corporation, is used to perform a magnetic field transient response analysis.

[0105] (Analysis of inductance) The inductance when a current of 0 A to 400 A flows through the coil is analyzed. The maximum value of the inductance is obtained based on the linked magnetic flux of the coil when the current value is 0 A. The inductance of each sample is shown in Table 1. The inductance shown in Table 1 is expressed as a ratio with the inductance of Sample No. 1-0 as the reference (100%).

[0106] (Analysis of Loss) Analyze the loss when a DC current of 0 A, an input voltage of 300 V, an output voltage of 600 V, and a voltage of 20 kHz are applied to the coil. Calculate the coil loss based on the magnetic flux density distribution and the current density distribution. Show the coil loss in each specimen in Table 1. The coil loss is expressed as a ratio with the coil loss of Specimen No. 1-0 as the reference (100%). In addition, show the coil loss reduction rate A in each specimen in Table 1. The coil loss reduction rate A is obtained by subtracting the coil loss of Specimen No. 1-0 from the coil loss in each specimen. If the coil loss reduction rate A is 1% or more, it is considered that the effect of reducing the coil loss is obtained.

[0107] (Evaluation of Volume Increase Rate) Measure the volume of the magnetic core of the reactor for each specimen. Here, find the volume of the first core in each specimen. Calculate the increase rate of the volume of the first core in Specimens No. 1-1 to No. 1-7 relative to the volume of the first core in Specimen No. 1-0. The volume increase rate is obtained as follows. Calculate the increase amount of the volume of the first core in each specimen relative to the volume of the first core in Specimen No. 1-0. The volume increase amount is obtained by subtracting the volume of the first core in Specimen No. 1-0 from the volume of the first core in each specimen. The volume increase rate expresses the volume increase amount Va of the volume of the first core in each specimen relative to the volume V0 of the first core in Specimen No. 1-0 as a percentage. That is, the volume increase rate is expressed as [Va / V0]×100. Show the volume increase rate B in each specimen in Table 1.

[0108] (Evaluation of Efficiency) Evaluate the efficiency of reducing the coil loss with respect to the volume increase of the first core for the reactor of each specimen. The efficiency expresses the coil loss reduction rate A with respect to the volume increase rate B as a percentage. The efficiency is expressed as [A / B]×100. Show the efficiency in each specimen in Table 1. When the value of this efficiency is 75% or more, it can be said that the efficiency of reducing the coil loss is high.

[0109] [Table 1] No.1-0 No.1-1 No.1-2 No.1-3 No.1-4 No.1-5 No.1-6 No.1-7 L40 (mm) 0 1 2.5 4 5.5 7 8.5 10 L35 (mm) 13.4 13.4 13..4 13.4 13.4 13.4 13.4 13.4 L40 / L35 0 0.07 0.19 0.30 0.41 0.52 0.63 0.75 Inductance (%) 100 100.2 100.5 100.7 100.9 101.0 101.2 101.4 Coil Loss (%) 100 98.8 97.8 97.1 96.5 95.9 95.4 94.8 Coil Loss Reduction Rate A (%) 0 1.2 2.2 2.9 3.5 4.1 4.6 5.2 Volume Increase Rate B (%) 0 0.8 2.1 3.4 4.6 5.9 7.1 8.4 Efficiency [A / B] (%) 0 150 105 85 76 69 65 62

[0110] As shown in Table 1, the coil loss reduction rate A of Specimens No. 1-1 to No. 1-7 is 1% or more. That is, the coil loss of Specimens No. 1-1 to No. 1-7 is reduced by 1% or more compared with the coil loss of Specimen No. 1-0. Therefore, it can be known that Specimens No. 1-1 to No. 1-7 obtain the effect of reducing the coil loss through the protrusion. In addition, the inductance of Specimens No. 1-1 to No. 1-7 is not reduced compared with the inductance of Specimen No. 1-0. It can be said that the protrusion has little effect on the inductance.

[0111] Regarding Specimens No. 1-1 to No. 1-7, the ratio of the length L40 of the protrusion to the length L35 of the first end core, i.e., L40 / L35, is 0.05 or more. From the results of Specimens No. 1-1 to No. 1-7, it can be seen that the larger the length L40, that is, the larger the ratio of the length L40 to the length L35, the easier it is to obtain the effect of reducing the coil loss. However, if the ratio of the length L40 to the length L35 is too large, the volume of the first core becomes large and the volume increase rate B becomes large. In addition, if the volume increase rate B becomes large, the efficiency tends to become low. Regarding Specimens No. 1-1 to No. 1-4 where L40 / L35 is 0.5 or less, the efficiency is 75% or more and they have high efficiency. It can be considered that the efficiency of reducing the coil loss is high, and the ratio of the length L40 to the length L35 for obtaining the effect of reducing the coil loss is 0.05 or more and 0.5 or less.

[0112] <Test Example 2> In Test Example 2, reactors of Specimens No. 2-0 to No. 2-7 shown in Design Table 2 were designed. Specimens No. 2-0 to No. 2-7 are models in which the widths W40 of the first protrusion 41 and the second protrusion 42 are changed within the range of 0 mm to 10 mm. Specimen No. 2-0 with a width W40 of 0 mm for the protrusion 40 does not have the first protrusion 41 and the second protrusion 42. Specimen No. 2-0 has the same structure as Specimen No. 1-0 in Test Example 1. The basic structure of the designed reactor is the same as that in Test Example 1.

[0113] The width W40 of the protrusion 40, the interval D33 between the middle core 31 and the side core 33, and the ratio (W40 / D33) of the width W40 to the interval D33 in Specimens No. 2-0 to No. 2-7 are shown in Table 2. In addition, the lengths L40 of the first protrusion 41 and the second protrusion 42 are 5 mm each. The length L35 of the first end core 35a is 13.4 mm. The ratio of the length L40 to the length L35 (L40 / L35) is 0.37.

[0114] The inductance and loss of the reactors of each specimen were analyzed. The inductance and coil loss in each specimen were obtained in the same manner as in Test Example 1. The inductance and coil loss in each specimen are shown in Table 2. The inductance shown in Table 2 is expressed as a ratio with the inductance of Specimen No. 2-0 as the reference (100%). The coil loss shown in Table 2 is expressed as a ratio with the coil loss of Specimen No. 2-0 as the reference (100%). In addition, the coil loss reduction rate A in each specimen is shown in Table 2. The coil loss reduction rate A is obtained by subtracting the coil loss of Specimen No. 2-0 from the coil loss in each specimen.

[0115] Further, the volume increase rate and efficiency in each specimen were obtained in the same manner as in Test Example 1. The volume increase rate B and efficiency in each specimen are shown in Table 2.

[0116] [Table 2] No.2-0 No.2-1 No.2-2 No.2-3 No.2-4 No.2-5 No.2-6 No.2-7 W40 (mm) 0 1 2.5 4 5.5 7 8.5 10 D33 (mm) 11 11 11 11 11 11 11 11 W40 / D33 0 0.09 0.23 0.36 0.50 0.64 0.77 0.91 Inductance (%) 100 100.3 100.4 100.5 100.5 100.6 100.7 100.7 Coil Loss (%) 100 99.1 98.8 98.6 98.2 97.8 97.4 97.0 Coil Loss Reduction Rate A (%) 0 0.9 1.2 1.4 1.8 2.2 2.6 3.0 Volume Increase Rate B (%) 0 0.4 1.0 1.5 2.1 2.7 3.2 3.8 Efficiency [A / B] (%) 0 225 120 93 86 81 81 79

[0117] As shown in Table 2, the coil loss reduction rate A of Specimens No. 2-2 to No. 2-7 is 1% or more. Therefore, it can be seen that Specimens No. 2-2 to No. 2-7 achieve the effect of reducing coil loss through the protruding portion. In addition, the inductance of Specimens No. 2-2 to No. 2-7 does not decrease compared with the inductance of Specimen No. 2-0. It can be said that the protruding portion has little influence on the inductance.

[0118] Regarding Specimens No. 2-2 to No. 2-7, the ratio of the width W40 of the protruding portion to the interval D33 between the middle core portion and the side core portion, that is, W40 / D33, is 0.2 or more. From the results of Specimens No. 2-1 to No. 2-7, it can be seen that the larger the width W40, that is, the larger the ratio of the width W40 to the interval D33, the easier it is to obtain the effect of reducing coil loss. Further, the efficiency of Specimens No. 2-2 to No. 2-7 with W40 / D33 of 1.0 or less is 75% or more, having high efficiency. It can be considered that the efficiency of reducing coil loss is high, and the ratio of the width W40 to the interval D33 for obtaining the effect of reducing coil loss is 0.2 or more and 1.0 or less.

[0119] <Test Example 3> The inductance and loss of the reactors of Modification Example 1 and Modification Example 2 were evaluated.

[0120] In Test Example 3, reactors of Specimens No. 3-1 and No. 3-2 shown in Table 3 were designed. Both Specimens No. 3-1 and No. 3-2 have a first protruding portion 41 and a second protruding portion 42. The basic structure of the designed reactors is the same as that of Test Example 1.

[0121] Specimen No. 3-1 has the same structure as Modification Example 1. The first protruding portion 41 and the second protruding portion 42 of Specimen No. 3-1 are each divided into two in the Z-axis direction. In Specimen No. 3-1, the protruding portions are respectively arranged at a portion near the upper edge and a portion near the lower edge of the outer side surface 352a. The sizes of the two protruding portions arranged along the Z-axis direction are the same. The height of the two protruding portions in the Z-axis direction is 7.5 mm. The sum of the heights of the two protruding portions is 15 mm.

[0122] Specimen No. 3-2 has the same structure as Modification Example 2. In Specimen No. 3-2, the first protruding portion 41 and the second protruding portion 42 are respectively arranged only at the central portion of the outer side surface 352a. The height of the protruding portion in the Z-axis direction is 15 mm.

[0123] The lengths L40 of the first protrusion 41 and the second protrusion 42 in Specimen No. 3-1 and Specimen No. 3-2 are each 5.5 mm. The ratio (L40 / L35) of the length L40 to the length L35 is 0.41. The widths W40 of the first protrusion 41 and the second protrusion 42 are each 11 mm. The ratio (W40 / D33) of the width W40 to the interval D33 is 1. The volume of the protrusion in Specimen No. 3-1 is equal to the volume of the protrusion in Specimen No. 3-2. That is, the volume of the first core in Specimen No. 3-1 is equal to the volume of the first core in Specimen No. 3-2.

[0124] The inductance and loss of the reactor for each specimen were analyzed. The inductance and coil loss in each specimen were determined in the same manner as in Test Example 1. The inductance and coil loss in each specimen are shown in Table 3. The inductance shown in Table 3 is expressed as a ratio with the inductance of Specimen No. 1-0 in Test Example 1 as the reference (100%). The coil loss shown in Table 3 is expressed as a ratio with the coil loss of Specimen No. 1-0 as the reference (100%). In addition, the reduction rate A of the coil loss in each specimen is shown in Table 3. The reduction rate A of the coil loss is obtained by subtracting the coil loss of Specimen No. 1-0 from the coil loss in each specimen.

[0125] [Table 3] No.3-1 No.3-2 Inductance (%) 100.6 100.7 Coil Loss (%) 97.3 97.7 Coil Loss Reduction Rate A (%) 2.7 2.3

[0126] As shown in Table 3, the reduction rate A of the coil loss of Specimen No. 3-1 and Specimen No. 3-2 is 1% or more. Comparing Specimen No. 3-1 and Specimen No. 3-2, it can be seen that the coil loss of Specimen No. 3-1 is less than the coil loss of Specimen No. 3-2. From the results, it is considered that arranging the protrusions at the portions near the upper edge and the lower edge of the outer side surface of the first end core portion can effectively reduce the coil loss.

[0127] <Test Example 4> The inductance and loss of a reactor having the same structure as the reactor 1b of Embodiment 2 were evaluated.

[0128] In Test Example 4, reactors of Specimen No. 4-0 to Specimen No. 4-7 shown in Table 4 were designed. Specimen No. 4-0 to No. 4-7 each have a first protrusion 41 and a second protrusion 42. Specimen No. 4-0 to No. 4-7 are models in which the angle of the inclined surface 33t on the inner side surface of the side core portion 33 is changed within the range of 0° to 7°. Specimen No. 4-0 has the same structure as Specimen No. 1-4 in Test Example 1. The basic structure of the designed reactor is the same as that in Test Example 1.

[0129] The lengths L40 of the first protruding portion 41 and the second protruding portion 42 in Specimens No. 4-0 to No. 4-7 are each 5.5 mm. The ratio of the length L40 to the length L35 (L40 / L35) is 0.41. The widths W40 of the first protruding portion 41 and the second protruding portion 42 are each 11 mm. The ratio of the width W40 to the interval D33 (W40 / D33) is 1.

[0130] The angles of the inclined surfaces in Specimens No. 4-0 to No. 4-7 are shown in Table 4. In addition, for each specimen, the first interval D1, the second interval D2, and the ratio of the first interval D1 to the second interval D2 (D1 / D2) are shown in Table 4. For Specimen No. 4-0 in which the angle of the inclined surface 33t is 0°, the interval between the side core portion 33 and the coil 2 is constant over the entire length of the side core portion 33. That is, in Specimen No. 4-0, the ratio of the first interval D1 to the second interval D2 is 1. The first interval D1 and the second interval D2 in Specimen No. 4-0 are each 2 mm.

[0131] The reactors of each specimen are analyzed for inductance and loss. The inductance and coil loss in each specimen are obtained in the same manner as in Test Example 1. The inductance and coil loss in each specimen are shown in Table 4. The inductance shown in Table 4 is expressed as a ratio with the inductance of Specimen No. 1-0 in Test Example 1 as the reference (100%). The coil loss shown in Table 4 is expressed as a ratio with the coil loss of Specimen No. 1-0 as the reference (100%). In addition, the coil loss reduction rate A in each specimen is shown in Table 4. The coil loss reduction rate A is obtained by subtracting the coil loss of Specimen No. 1-0 from the coil loss in each specimen.

[0132] [Table 4] No.1-0 No.4-0 No.4-1 No.4-2 No.4-3 No.4-4 No.4-5 No.4-6 No.4-7 Presence or Absence of Protrusion Absence Presence Presence Presence Presence Presence Presence Presence Presence Angle of Inclined Plane (°) 0 0 1 2 3 4 5 6 7 D1 (mm) 2 2 2 2 2 2 2 2 2 D2 (mm) 2 2 2.9 3.8 4.7 5.7 6.6 7.5 8.5 D1 / D2 1 1 0.69 0.53 0.43 0.35 0.31 0.27 0.24 Inductance (%) 100 100.9 100.1 97.4 96.4 95.3 94.3 93.0 91.5 Coil Loss (%) 100 96.5 95.2 94.1 93.2 92.6 92.4 92.4 93.1 Coil Loss Reduction Rate A (%) 0 3.5 4.8 5.9 7.8 7.4 7.6 7.6 6.9

[0133] As shown in Table 4, the coil losses of Specimens No. 4-1 to No. 4-7 are further reduced compared to that of Specimen No. 4-0. The second interval D2 of Specimens No. 4-1 to No. 4-7 is larger than the first interval D1, and the ratio of the first interval D1 to the second interval D2 is 0.70 or less. From the results of Specimens No. 4-1 to No. 4-7, it can be seen that: the larger the second interval D2, that is, the smaller the ratio of the first interval D1 to the second interval D2, the easier it is to obtain the effect of reducing the coil loss. However, it can be seen that: if the ratio of the first interval D1 to the second interval D2 becomes smaller, the inductance decreases. The inductances of Specimens No. 4-1 to No. 4-4 are reduced by less than 5% compared to that of Specimen No. 1-0. If the reduction of the inductance is less than 5%, it can be regarded as an inductance approximately equal to that of Specimen No. 1-0. The ratio of the first interval D1 to the second interval D2 of Specimens No. 4-1 to No. 4-4 is 0.32 or more. It can be considered that: the ratio of the first interval D1 to the second interval D2 that maintains the inductance well and obtains the effect of reducing the coil loss is 0.32 or more and 0.70 or less. Description of Reference Numerals

[0134] 1a, 1b Reactor 2 Coil 2a First end face, 2b Second end face 3 Magnetic core 3a First core, 3b Second core 31 Intermediate core part 31a First intermediate core part, 31b Second intermediate core part 31g Gap part 32a First end, 32b Second end 33 Side core part 331 First side core part, 332 Second side core part 33t Inclined surface, 33s Step part 34a First end, 34b Second end 341 First region, 342 Second region 35 End core part 35a First end core part, 35b Second end core part 351a, 351b Inner side surfaces 352a, 352b Outer side surfaces 40 Protrusion 41 First protrusion, 42 Second protrusion D1 First interval, D2 Second interval D33 Interval L, L40, L35 Lengths W, W40 Widths H height 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 Electric motor, 1230 Auxiliary battery 1240 Auxiliary equipment, 1250 Wheel 1300 Engine

Claims

1. A reactor, comprising a coil and a magnetic core, The coil has a cylindrical shape, and the magnetic core has a θ shape, The coil has a first end face and a second end face, The magnetic core includes a first core and a second core, The first core includes at least a part of a first end core portion and a side core portion, The second core includes a second end core portion and the remaining part of the side core portion, At least one of the first core and the second core includes at least a part of an intermediate core portion, The first end core portion is arranged to face the first end face of the coil, The second end core portion is arranged to face the second end face of the coil, The intermediate core portion is arranged inside the coil, The side core portion has a first side core portion and a second side core portion arranged side by side with the intermediate core portion with the coil therebetween, The first core is formed of a composite material body in which soft magnetic powder is dispersed in resin, The first end core portion has: An inner side face that is combined with the first ends of the intermediate core portion, the first side core portion, and the second side core portion respectively; An outer side face that faces the side opposite to the inner side face; and A protruding portion provided on the outer side face, The protruding portion includes a first protruding portion and a second protruding portion, The first protruding portion is provided at a position corresponding to the portion between the intermediate core portion and the first side core portion on the outer side face, The second protruding portion is provided at a position corresponding to the portion between the intermediate core portion and the second side core portion on the outer side face.

2. The reactor according to claim 1, wherein, The length of the first protruding portion and the length of the second protruding portion are each 0.05 times or more and 0.5 times or less of the length of the first end core portion.

3. The reactor according to claim 1 or claim 2, wherein, The width of the first protruding portion is 0.2 times or more and 1.0 times or less of the interval between the intermediate core portion and the first side core portion, The width of the second protruding portion is 0.2 times or more and 1.0 times or less of the interval between the intermediate core portion and the second side core portion.

4. The reactor according to any one of claims 1 to 3, wherein The relative magnetic permeability of the first core is 5 or more and 50 or less.

5. The reactor according to any one of claims 1 to 4, wherein, The intermediate core portion has a first intermediate core portion and a second intermediate core portion, The first intermediate core portion is combined with the first end core portion, The second intermediate core portion is combined with the second end core portion.

6. The reactor according to claim 5, wherein, The intermediate core portion has a gap portion between the first intermediate core portion and the second intermediate core portion.

7. The reactor according to any one of claims 1 to 6, wherein, The first core includes all of the side core portion, The relative magnetic permeability of the first core is lower than that of the second core, The first side core portion and the second side core portion each have a first end combined with the first end core portion and a second end combined with the second end core portion, Regarding the interval between the first side core portion and the coil and the interval between the second side core portion and the coil, the second interval at the second end is greater than the first interval at the first end, The ratio of the first interval to the second interval is 0.32 or more and 0.70 or less.

8. The reactor according to claim 7, wherein, The first side core portion and the second side core portion each have a tapered shape with a width that tapers from the first end toward the second end.

9. The reactor according to claim 7, wherein, The first side core portion and the second side core portion each have a stepped shape with a width that tapers from the first end toward the second end.

10. The reactor according to any one of claims 1 to 9, wherein, The relative magnetic permeability of the second core is 100 or more and 500 or less.

11. The reactor according to any one of claims 1 to 10, wherein The second core is composed of a compacted powder body.

12. A converter including the reactor according to any one of claims 1 to 11.

13. A power conversion device including the converter according to claim 12.

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