Reactor, converter, and power conversion device

Abstract

This reactor is provided with: a coil having a winding part configured by a winding of multiple turns; a first holding member disposed so as to face a first end surface of the winding part; and a second holding member disposed so as to face a second end surface of the winding part. Each of the multiple turns comprises a first straight-line part, a first curve part, a second straight-line part, and a second curve part that are arranged in order around the axis of the winding part. Each of the first holding member and the second holding member is provided with two protrusions for positioning the winding part. The two protrusions each comprise a first protrusion that is in contact with at least part of the first curve part and a second protrusion that is in contact with at least part of the second curve part.

Description

Reactors, converters, and power conversion devices

[0001] This disclosure relates to a reactor, a converter, and a power conversion device. This application claims priority to Japanese Patent Application No. 2023-198642 filed on November 22, 2023, and incorporates by reference all of the contents of said Japanese application.

[0002] Patent Document 1 discloses a reactor including a coil, a magnetic core, and a holding member. The coil includes a main body portion composed of multiple turns. Each turn has four straight portions where the winding is arranged linearly and four corner portions where the winding is bent. The holding members are disposed at each end of the main body portion and ensure electrical insulation between the main body portion and the magnetic core. The holding member has multiple inner protrusions that position the coil. The multiple inner protrusions are typically provided at locations corresponding to each side of the inner circumferential surface of the main body portion.

[0003] JP 2022-188850 A

[0004] The reactor disclosed herein includes a coil having a winding portion formed of a plurality of turns of wire, a first holding member arranged to face a first end face of the winding portion, and a second holding member arranged to face a second end face of the winding portion. Each of the plurality of turns includes a first straight portion, a first curved portion, a second straight portion, and a second curved portion arranged in this order around the axis of the winding portion. Each of the first holding member and the second holding member includes two protrusions that position the winding portion. The two protrusions include a first protrusion that contacts at least a portion of the first curved portion and a second protrusion that contacts at least a portion of the second curved portion.

[0005] FIG. 1 is a schematic perspective view showing the entire reactor of the first embodiment. FIG. 2 is a schematic perspective view showing a state in which a coil, a first holding member, and a second holding member of the reactor of the first embodiment are assembled. FIG. 3 is a schematic perspective view showing a state in which the coil, the first holding member, and the second holding member of FIG. 2 are disassembled. FIG. 4 is a schematic plan view showing one turn of the coil of FIG. 2. FIG. 5 is a schematic perspective view showing a core of the reactor of the first embodiment. FIG. 6 is a schematic perspective view showing a relationship between a middle core portion and a first holding member of the reactor of the first embodiment. FIG. 7 is a schematic perspective view showing the entire reactor of the second embodiment. FIG. 8 is a schematic plan view showing one turn of the coil of FIG. 7. FIG. 9 is a schematic perspective view showing the entire reactor of the third embodiment. FIG. 10 is a schematic perspective view showing a state in which the coil, the first holding member, and the second holding member of the reactor of the third embodiment are assembled. FIG. 11 is a schematic perspective view showing a state in which the coil, the first holding member, and the second holding member of FIG. 10 are disassembled. Fig. 12 is a schematic plan view showing one turn of the coil of Fig. 10. Fig. 13 is a schematic perspective view showing the relationship between a middle core portion and a first holding member of a reactor of embodiment 3. Fig. 14 is a configuration diagram schematically showing a power supply system of a hybrid vehicle. Fig. 15 is a circuit diagram showing an example of a power conversion device including a converter.

[0006] [Problem to be Solved by the Present Disclosure] A holding member with high rigidity is desired. In the holding member disclosed in Patent Document 1, one or more inner protrusions are provided at each location corresponding to the four straight portions of the turns that make up the main body, and the number of inner protrusions is large and each inner protrusion is small. Small inner protrusions have low rigidity and tend to reduce the coil positioning accuracy. If the number of inner protrusions is large, the number of objects that need to be inspected for the formability of the inner protrusions, such as the presence or absence of voids and their dimensions, increases, reducing productivity.

[0007] One object of the present disclosure is to provide a reactor having a holding member for positioning a coil that is excellent in rigidity and that is easy to manufacture. Another object of the present disclosure is to provide a converter including the reactor. Another object of the present disclosure is to provide a power conversion device including the converter.

[0008] [Effects of the Present Disclosure] In the reactor of the present disclosure, the holding member that positions the coil has excellent rigidity.

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0010] (1) A reactor according to an embodiment of the present disclosure includes a coil having a winding portion formed of a plurality of turns of wire, a first holding member arranged to face a first end surface of the winding portion, and a second holding member arranged to face a second end surface of the winding portion. Each of the plurality of turns includes a first straight portion, a first curved portion, a second straight portion, and a second curved portion arranged in this order around the axis of the winding portion. Each of the first holding member and the second holding member includes two protrusions that position the winding portion. The two protrusions include a first protrusion that contacts at least a portion of the first curved portion and a second protrusion that contacts at least a portion of the second curved portion.

[0011] Because the number of protrusions on the first or second holding member provided at the first end of one winding portion is two, the number of objects to be inspected for the formability of the protrusions is small. Inspection of the formability of the protrusions includes, for example, the presence or absence of porosity and dimensional control. A reactor with a small number of objects to be inspected is highly productive. Even if the number of protrusions on each of the first and second holding members is two for each end of one winding portion, the two protrusions are provided corresponding to the first and second curved portions of the turns that make up the winding portion, making it easy to increase the size of each protrusion. The curved portion is a portion consisting only of curves and does not include a portion consisting of straight lines. Large protrusions have high rigidity. A holding member with large protrusions has excellent rigidity.

[0012] (2) In the reactor described in (1) above, each of the first curved portion and the second curved portion may have a semicircular shape.

[0013] A turn composed of a first straight portion, a first curved portion, a second straight portion, and a second curved portion is suitable for a flat winding portion. In particular, if the first curved portion and the second curved portion each have a semicircular shape, it is easy to manufacture a flat winding portion. If the winding portion is flat, it is easy to form a flat reactor.

[0014] (3) In the reactor described in (1) or (2) above, each of the first protrusion and the second protrusion may have a shape that follows the inner circumferential shape of the winding portion.

[0015] When the shapes of the first protrusion and the second protrusion are aligned with the inner circumferential shape of the winding portion, i.e., when the shapes of the first curved portion and the second curved portion are aligned with the inner circumferential shape of the winding portion, the first protrusion can easily support the first curved portion, and the second protrusion can easily support the second curved portion. Even with two protrusions, as long as both curved portions can be supported, the winding portion can be positioned with high accuracy.

[0016] (4) In the reactor according to any one of (1) to (3) above, the coil may be an edgewise coil made of a rectangular wire.

[0017] An edgewise coil made of rectangular wire can have a short winding length, which is the length along the axis of the winding.

[0018] (5) In the reactor described in any one of (1) to (4) above, a first length of each of the first straight portion and the second straight portion may be longer than a second length between the first straight portion and the second straight portion.

[0019] The winding portion in which the first length is longer than the second length is flat. If the winding portion is flat, the entire reactor is likely to be flat. A flat reactor can be easily arranged in any space, and has excellent arrangement freedom.

[0020] (6) A converter according to an embodiment of the present disclosure includes the reactor according to any one of (1) to (5) above.

[0021] A converter including the reactor is excellent in productivity.

[0022] (7) A power conversion device according to an embodiment of the present disclosure includes the converter described in (6) above.

[0023] A power conversion device including the converter described above is highly productive.

[0024] [Details of the Embodiments of the Present Disclosure] Specific examples of the embodiments of the present disclosure will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same objects. In each drawing, for the convenience of explanation, some components may be exaggerated or simplified. The dimensional ratios of each part in the drawings may also differ from the actual ratios. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0025] First Embodiment A reactor 1α of a first embodiment will be described with reference to FIGS. 1 to 6 . As shown in FIG. 1 , the reactor 1α includes a coil 2, a first holding member 5, a second holding member 6, and a magnetic core 8. The coil 2 has a winding portion 20 formed of a winding 3 with a plurality of turns 4. One of the features of the reactor 1α is that, as shown in FIG. 4 , each turn 4 includes a first straight portion 41, a first curved portion 43, a second straight portion 42, and a second curved portion 44. Another feature of the reactor 1α is that, as shown in FIGS. 3 and 4 , the first holding member 5 includes two protrusions, a first protrusion 51 and a second protrusion 52. Yet another feature of the reactor 1α is that, as shown in FIGS. 2 and 3 , the second holding member 6 includes two protrusions, a first protrusion 61 and a second protrusion 62. The first protrusions 51 and second protrusions 52 of the first holding member 5 and the first protrusions 61 and second protrusions 62 of the second holding member 6 are provided in a number corresponding to the number of winding portions 20 .

[0026] <Coil> The coil 2 has at least one winding portion 20. The coil 2 in this example has one winding portion 20. The winding portion 20 is formed by winding the wire 3 in a spiral shape. Both ends of the winding 3 are drawn out from the respective ends of the winding portion 20. Terminal fittings (not shown) are attached to both ends of the winding 3 drawn out from the winding portion 20. An external device (not shown) is connected to the terminal fittings. In each drawing, only the winding portion 20 is shown, and both ends of the winding 3 are omitted.

[0027] The winding 3 can be a known winding. In this example, the winding 3 is a rectangular wire having a conductor wire and an insulating coating covering the conductor wire. The conductor wire is made of, for example, a rectangular copper wire. The insulating coating is made of, for example, enamel. The coil 2 in this example is an edgewise coil made of a rectangular wire. An edgewise coil made of a rectangular wire can shorten the length along the axis of the winding portion 20. The length of the winding portion 20 is the length along the axis of the winding portion 20.

[0028] The winding portion 20 is made up of a plurality of turns 4. As shown in Fig. 4, each turn 4 is made up of a first straight portion 41, a first curved portion 43, a second straight portion 42, and a second curved portion 44, which are arranged in this order around the axis of the winding portion 20. Fig. 4 shows any one of the plurality of turns 4. In Fig. 4, the transition points between adjacent turns 4 are indicated by imaginary two-dot chain lines. For ease of explanation, Fig. 4 shows the winding portion 20 with a first holding member 5, which will be described later, attached thereto.

[0029] The first straight portion 41 and the second straight portion 42 are vertically symmetrical and have the same length L1. Vertical symmetry means that the first straight portion 41 coincides with the second straight portion 42 when rotated 180° around the axis of the winding portion 20. The first straight portion 41 and the second straight portion 42 are parallel to each other. The first curved portion 43 and the second curved portion 44 are horizontally symmetrical and have the same length. Horizontal symmetry means that the first curved portion 43 coincides with the second curved portion 44 when rotated 180° around the axis of the winding portion 20. The contour shape of each turn 4, which is composed of the first straight portion 41, the first curved portion 43, the second straight portion 42, and the second curved portion 44, is a racetrack shape, as shown in FIG. 4 . The contour shapes of the first end face 21 and the second end face 22 of the winding portion 20 are also racetrack shapes.

[0030] Here, three directions in reactor 1α are defined with respect to winding portion 20. The three directions are a first direction D1, a second direction D2, and a third direction D3. First direction D1 is a direction from first end surface 21 to second end surface 22 shown in FIG. 3 along the axis of winding portion 20. Second direction D2 is a direction perpendicular to first direction D1 and is a direction from first curved portion 43 to second curved portion 44 shown in FIG. 4. Third direction D3 is a direction perpendicular to first direction D1 and is a direction from first straight portion 41 to second straight portion 42 shown in FIG. 4. Hereinafter, the opposite directions of first direction D1, second direction D2, and third direction D3 may also be referred to as first direction D1, second direction D2, and third direction D3.

[0031] As shown in FIG. 4 , the length L1 of each of the first straight portion 41 and the second straight portion 42 is longer than, for example, the length L2 between the first straight portion 41 and the second straight portion 42. The length L2 is the length along the third direction D3 between the surfaces where the first straight portion 41 and the second straight portion 42 face each other. The first curved portion 43 is connected to a first end of the first straight portion 41, and the second curved portion 44 is connected to a second end of the first straight portion 41. The length L1 is also the minimum length along the second direction D2 between the first curved portion 43 and the second curved portion 44. The length L2 is also the minimum length along the third direction D3 connecting the ends of the first curved portion 43.

[0032] The winding portion 20, in which the length L1 is longer than the length L2, has a flat shape that is thinner in the third direction D3. The turn 4, which is composed of the first straight portion 41, the first curved portion 43, the second straight portion 42, and the second curved portion 44, is suitable for a flat winding portion 20. In the flat winding portion 20, the ratio L2 / L1 of the length L2 to the length L1 is, for example, 1 / 10 or more and 1 / 3 or less. The ratio L2 / L1 may be 1 / 10 or more and 1 / 4 or less, or 1 / 10 or more and 1 / 5 or less. If the winding portion 20 is flat, the entire reactor 1α also tends to be flat. The flat reactor 1α can be easily arranged in any space and has excellent flexibility in arrangement.

[0033] Each of the first curved portion 43 and the second curved portion 44 has, for example, a semicircular shape. If each of the first curved portion 43 and the second curved portion 44 has a semicircular shape, it is easier to manufacture a flat winding portion 20. The first curved portion 43 and the second curved portion 44 may be formed by any curve as long as they do not include any straight line portions. The first curved portion 43 and the second curved portion 44 may also be formed in a semi-elliptical shape. The first curved portion 43 and the second curved portion 44 are formed by bending the winding 3 along the outer circumferential surface of a shaft (not shown) during the manufacturing process of the coil 2. By changing the shape of this shaft, the first curved portion 43 and the second curved portion 44 can be formed in a semicircular or semi-elliptical shape.

[0034] <First Holding Member> As shown in Fig. 3 , the first holding member 5 is arranged to face the first end surface 21 of the winding portion 20. The first holding member 5 has the function of ensuring electrical insulation between the winding portion 20 and a first end core portion 821, which will be described later. The first holding member 5 includes a main body portion 50, a first protrusion 51, and a second protrusion 52. The first holding member 5 of this example further includes a side portion 55.

[0035] The main body portion 50 is a plate-like member disposed between the winding portion 20 and the first end core portion 821. The main body portion 50 has through holes 50h that penetrate the front and back of the main body portion 50. The through holes 50h are provided to connect the inner core portion 81, which will be described later, and the first end core portion 821. The shape of the through holes 50h is generally similar to the outline shape of each turn 4. The outline shape of the through holes 50h is a racetrack shape. The outline shape of the through holes 50h has a flat shape that becomes thinner in the third direction D3.

[0036] The first protrusion 51 and the second protrusion 52 have the function of positioning the winding portion 20. The first holding member 5 is provided with two protrusions for positioning the winding portion 20. These two protrusions are the first protrusion 51 and the second protrusion 52. In other words, the first holding member 5 is not provided with any protrusions for positioning the winding portion 20 other than the first protrusion 51 and the second protrusion 52.

[0037] The first protrusion 51 and the second protrusion 52 are provided at positions facing each other on the inner circumferential surface of the through hole 50h. The positions on the inner circumferential surface of the through hole 50h where the first protrusion 51 and the second protrusion 52 are provided protrude from other positions by the thickness of the first protrusion 51 and the second protrusion 52. The first protrusion 51 and the second protrusion 52 protrude along the first direction D1 toward the second holding member 6 beyond the surface of the main body 50 facing the first end face 21 of the winding portion 20. The protruding length of the first protrusion 51 and the second protrusion 52 is, for example, a length that contacts two or more turns of the winding portion 20. This protruding length is the length of the first protrusion 51 and the second protrusion 52 along the first direction D1 from the surface of the main body 50 facing the first end face 21. When the first protrusion 51 and the second protrusion 52 are provided so as to contact two or more turns from each end of the winding portion 20, the first holding member 5 can easily position the coil 2 with high precision. The protruding length of the first protruding portion 51 and the second protruding portion 52 in this example is a length that contacts two turns of the winding portion 20 .

[0038] The first protrusion 51 is arranged so as to be in contact with at least a portion of the first curved portion 43 shown in FIG. 4 . In this example, the first protrusion 51 is arranged so as to be in contact with the inner surface of the first curved portion 43. In this example, the first protrusion 51 has a shape that follows the inner circumferential shape of the winding portion 20. In this example, the outer circumferential surface of the first protrusion 51 and the inner circumferential surface of the winding portion 20 are flush with each other. In this example, the first protrusion 51 has a shape that follows the inner circumferential shape of the first curved portion 43. In this example, the first curved portion 43 has a semicircular shape, and the first protrusion 51 also has a semicircular shape. As long as the first protrusion 51 has a shape that follows the inner circumferential shape of the first curved portion 43, there may be a small clearance between the first protrusion 51 and the first curved portion 43. The first protrusion 51 may be arranged so as to be in contact with not only the first curved portion 43 but also a portion of the first straight portion 41 and a portion of the second straight portion 42. The first protrusion 51 is provided so as to contact only the first curved portion 43, which makes it easy to assemble the first protrusion 51 to the winding portion 20. When the first protrusion 51 is provided so as to contact the entire surface of the first curved portion 43 as viewed from the first direction D1, the strength of the first protrusion 51 is higher than when the first protrusion 51 is provided so as to contact only a portion of the first curved portion 43, and the first protrusion 51 is able to stably support the winding portion 20. The first protrusion 51 may be provided so as to contact only a portion of the first curved portion 43. In this case, the first protrusion 51 is in contact with, for example, the portion of the first curved portion 43 that is located farthest outward in the second direction D2.

[0039] The second protrusion 52 is arranged so as to be in contact with at least a portion of the second curved portion 44 shown in FIG. 4 . In this example, the second protrusion 52 is arranged so as to be in contact with the inner surface of the second curved portion 44. In this example, the second protrusion 52 has a shape that follows the inner circumferential shape of the winding portion 20. In this example, the outer circumferential surface of the second protrusion 52 and the inner circumferential surface of the winding portion 20 are flush with each other. In this example, the second protrusion 52 has a shape that follows the inner circumferential shape of the second curved portion 44. In this example, the second curved portion 44 has a semicircular shape, and the second protrusion 52 also has a semicircular shape. Even if the second protrusion 52 has a shape that follows the inner circumferential shape of the second curved portion 44, there may be a small clearance between the second protrusion 52 and the second curved portion 44. The second protrusion 52 may be arranged so as to be in contact with not only the second curved portion 44 but also a portion of the first straight portion 41 and a portion of the second straight portion 42. The second protrusion 52 is provided so as to contact only the second curved portion 44, which makes it easier to assemble the second protrusion 52 to the winding portion 20. When the second protrusion 52 is provided so as to contact the entire surface of the second curved portion 44 as viewed from the first direction D1, the strength of the second protrusion 52 is higher than when the second protrusion 52 is provided so as to contact only a portion of the second curved portion 44, and the second protrusion 52 is more likely to stably support the winding portion 20. The second protrusion 52 may be provided so as to contact only a portion of the second curved portion 44. In this case, the second protrusion 52 is provided so as to contact, for example, the second curved portion 44 at a location that is located farthest outward in the second direction D2.

[0040] The first protrusion 51 and the second protrusion 52 are, for example, bilaterally symmetrical. Bilateral symmetry means that the first protrusion 51 coincides with the second protrusion 52 when rotated 180° around the axis of the winding portion 20. The first protrusion 51 and the second protrusion 52 may be asymmetrical. The first protrusion 51 and the second protrusion 52 may have different protruding lengths along the first direction D1. The first protrusion 51 and the second protrusion 52 may have different lengths around the axis of the winding portion 20. The first protrusion 51 and the second protrusion 52 are arranged so as to contact the outermost portions of the first curved portion 43 and the second curved portion 44. The first protrusion 51 and the second protrusion 52 need only face each other and have an overlapping region, and need not overlap the entire region. The overlapping region of the first protrusion 51 and the second protrusion 52 facing each other is the region that contacts the outermost portions of the first curved portion 43 and the second curved portion 44.

[0041] First protrusion 51 may be provided so as to contact at least a portion of the outer surface of first curved portion 43, and second protrusion 52 may be provided so as to contact at least a portion of the outer surface of second curved portion 44. In this case, each of first protrusion 51 and second protrusion 52 may have a shape that follows the outer peripheral shape of winding portion 20.

[0042] Because the first holding member 5 has two protrusions, the first protrusion 51 and the second protrusion 52, the number of objects to be inspected for the formability of the protrusions is small. Even if the first holding member 5 has two protrusions, the first protrusion 51 corresponds to the first curved portion 43, and the second protrusion 52 corresponds to the second curved portion 44, making it easy to increase the rigidity of the first protrusion 51 and the second protrusion 52. The first holding member 5 having the highly rigid first protrusion 51 and second protrusion 52 has excellent rigidity.

[0043] As shown in FIGS. 2 and 3 , the side portion 55 is provided to extend in the first direction D1 from one end of the main body portion 50 in the second direction D2. The side portion 55 is disposed between the side core portion 823 shown in FIG. 1 and the winding portion 20. As shown in FIG. 3 , the surface of the side portion 55 facing the winding portion 20 is an arcuate surface that follows the outer shape of the winding portion 20. An engaging portion (not shown) may be provided at the tip of the side portion 55 in the first direction D1. This engaging portion engages with an engaging portion (not shown) provided on a side portion 65 of the second holding member 6, which will be described later. A gap 7 is provided between the side portion 55 and the winding portion 20, as shown in FIG. 4 , for example. The provision of the gap 7 facilitates the positioning of the first protrusion 51 and the second protrusion 52 on the inner circumferential surface of the winding portion 20. The provision of the gap 7 eliminates the need to precisely match the spacing between the first protrusion 51 and the side portion 55 to the width of the winding 3, thereby eliminating the need for high molding precision.

[0044] The side portions 55 have the function of determining the relative positions of the first holding member 5 and the second holding member 6. Furthermore, when a side core portion 823 (described later) is made of a composite material, the side portions 55 also have the function of preventing the composite material from coming into contact with the winding portion 20 during molding of the side core portion 823.

[0045] The first holding member 5 is made of an electrically insulating material, such as polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin, liquid crystal polymer (LCP), polyamide (PA) resin such as nylon 6 or nylon 66, polybutylene terephthalate (PBT) resin, or acrylonitrile butadiene styrene (ABS) resin. The material of the first holding member 5 may be a thermosetting resin, such as unsaturated polyester resin, epoxy resin, urethane resin, or silicone resin. These resins may contain a ceramic filler. The ceramic filler may be a non-magnetic powder such as alumina or silica.

[0046] <Second Holding Member> As shown in Fig. 3 , the second holding member 6 is arranged to face the second end surface 22 of the winding portion 20. The second holding member 6 has the function of ensuring electrical insulation between the winding portion 20 and a second end core portion 822, which will be described later. The second holding member 6 includes a main body portion 60, a first protrusion 61, and a second protrusion 62. The main body portion 60 is a plate-like member that is arranged between the winding portion 20 and the second end core portion 822. The main body portion 60 includes a through-hole 60h that penetrates from the front to the back of the main body portion 60. The second holding member 6 of this example further includes a side portion 65.

[0047] The second holding member 6 has a configuration similar to that of the first holding member 5. The second holding member 6 can be explained by replacing the "main body portion 50," "through hole 50h," "first protrusion portion 51," "second protrusion portion 52," and "side portion 55" of the first holding member 5 described above with "main body portion 60," "through hole 60h," "first protrusion portion 61," "second protrusion portion 62," and "side portion 65," respectively.

[0048] Because the second holding member 6 has two protrusions, the first protrusion 61 and the second protrusion 62, the number of objects to be inspected for the formability of the protrusions is small. Even if the second holding member 6 has two protrusions, the first protrusion 61 corresponds to the first curved portion 43, and the second protrusion 62 corresponds to the second curved portion 44, making it easy to increase the rigidity of the first protrusion 61 and the second protrusion 62. The second holding member 6 having the highly rigid first protrusion 61 and second protrusion 62 has excellent rigidity.

[0049] The second holding member 6 in this example has the same shape and dimensions as the first holding member 5. When the second holding member 6 in this example is rotated 180 degrees around an axis parallel to the second direction D2, it coincides with the first holding member 5. The first holding member 5 and the second holding member 6 may have portions with different shapes or dimensions.

[0050] <Magnetic Core> The coil 2 is disposed in the magnetic core 8. As shown in Fig. 5 , the magnetic core 8 includes an inner core portion 81 and an outer core portion 82. The inner core portion 81 and the outer core portion 82 are configured as a continuous unit, so that a closed magnetic path is formed in the magnetic core 8 through which magnetic flux flows when the coil 2 is excited. The magnetic core 8 of this example is an integral molding in which the inner core portion 81 and the outer core portion 82 are configured without any joints. The magnetic core 8 of this example is configured from a molding of a composite material, which will be described later.

[0051] The inner core portions 81 are portions arranged inside the winding portions 20 of the coil 2. The number of inner core portions 81 is the same as the number of winding portions 20. Since there is only one winding portion 20 in this example, there is also only one inner core portion 81 in this example. The inner core portions 81 extend along the first direction D1. The ends of the inner core portions 81 may protrude from the ends of the winding portions 20. This protruding portion is also part of the inner core portion 81. In other words, the length of the inner core portions 81 along the first direction D1 may be longer than the length of the winding portions 20 along the first direction D1.

[0052] The shape of the inner core portion 81 roughly corresponds to the inner circumferential shape of the winding portion 20. In this example, two recesses 810 are provided at both end portions of the inner core portion 81, as shown in Figures 5 and 6. For ease of explanation, Figure 6 shows a state in which the first holding member 5 is assembled to the first end portion of the inner core portion 81. For ease of understanding, Figure 6 does not show the outer core portion 82 shown in Figure 5.

[0053] The two recesses 810 provided at the first end of the inner core portion 81 are provided to correspond to the first protrusion 51 and the second protrusion 52 provided on the first holding member 5. A part of the first end of the inner core portion 81 is fitted into a through hole 50h provided in the main body portion 50 of the first holding member 5. When the first holding member 5 is assembled to the first end of the inner core portion 81, the outer peripheral surface of the inner core portion 81 and the outer surfaces of the first protrusion 51 and second protrusion 52 are flush with each other.

[0054] 2 and 3 . A portion of the second end of the inner core portion 81 is fitted into a through hole 60h provided in the main body portion 60 of the second holding member 6. When the second holding member 6 is assembled to the second end of the inner core portion 81, the outer peripheral surface of the inner core portion 81 and the outer surfaces of the first and second protrusions 61 and 62 are flush with each other.

[0055] The outer core portion 82 is a portion disposed outside the winding portion 20 of the coil 2. The shape of the outer core portion 82 is not particularly limited as long as it is a shape that connects to the end of the inner core portion 81. As shown in FIGS. 1 and 5 , the outer core portion 82 in this example includes a first end core portion 821, a second end core portion 822, and a side core portion 823. The first end core portion 821 is provided so as to face the first holding member 5 and is connected to a first end of the inner core portion 81. The second end core portion 822 is provided so as to face the second holding member 6 and is connected to a second end of the inner core portion 81. The side core portion 823 connects the first end core portion 821 and the second end core portion 822. The shape of the outer core portion 82, in which the first end core portion 821, the second end core portion 822, and the side core portion 823 are connected, is a rectangular C-shape when viewed from the third direction D3.

[0056] The magnetic core 8 in this example is composed of a composite material compact. The composite material compact is manufactured by filling a mold with raw material, in which soft magnetic powder is mixed and dispersed in unsolidified resin, and then solidifying the resin. The magnetic core 8 is manufactured, for example, as follows: An assembly is prepared by assembling a first holding member 5 and a second holding member 6 to a coil 2, as shown in FIG. 2 . This assembly is placed in a mold. The raw material is then filled into the mold with the assembly placed therein. The raw material is filled from a position corresponding to either the first end core portion 821 or the second end core portion 822. The raw material flows along the shape of the mold and the inner peripheral shape of the winding portion 20. When the resin is solidified, the magnetic core 8 as shown in FIG. 5 is molded, and the reactor 1α as shown in FIG. 1 is manufactured. In the inner core portion 81, the recess 810 directly contacts the first protrusions 51, 61 and the second protrusions 52, 62, and the portions other than the recess 810 directly contact the inner peripheral surface of the winding portion 20.

[0057] The magnetic properties of the composite material, such as the magnetic permeability or saturation magnetic flux density, can be easily controlled by adjusting the content of the soft magnetic powder in the resin. In particular, the content of the soft magnetic powder in the composite material can be easily adjusted to a low level, thereby lowering the magnetic permeability. A compact of the composite material can be easily molded into a complex shape compared to a powder compact, which will be described later. A compact of the composite material can easily be molded into a magnetic core 8 that is compatible with a relatively complex shape, such as the first protrusion 51 and the second protrusion 52.

[0058] The soft magnetic powder is composed of, for example, soft magnetic metal particles, coated particles, or soft magnetic non-metal particles. The coated particles include soft magnetic metal particles and an insulating coating formed on the outer periphery of the soft magnetic metal particles. The soft magnetic metal is, for example, pure iron or an iron-based alloy. The iron-based alloy is, for example, an Fe-Si alloy or an Fe-Ni alloy. The insulating coating is, for example, a phosphate. The soft magnetic non-metal is, for example, ferrite. The content of the soft magnetic powder in the composite material compact is, for example, 20% by volume or more and 80% by volume or less, assuming the composite material to be 100% by volume. The resin is, for example, PPS resin, PTFE resin, LCP, PA resin, PBT resin, or ABS resin. The resin may also be BMC (bulk molding compound), which is an unsaturated polyester mixed with calcium carbonate or glass fiber, millable silicone rubber, or millable urethane rubber.

[0059] The magnetic core 8 may be made of a powder compact. The magnetic core 8 made of a powder compact has a plurality of core pieces. The magnetic core 8 made of a powder compact has a joint between the core pieces at some location on the magnetic core 8. The magnetic core 8 may be made by combining core pieces made of a powder compact and core pieces made of a composite material compact. The magnetic core 8 may be made by covering the outer periphery of a core piece made of a powder compact with a composite material.

[0060] The powder compact is produced by pressing raw material powder containing soft magnetic powder. The powder compact can have a higher soft magnetic powder content than a composite material compact. A powder compact with a higher soft magnetic powder content has high magnetic permeability. The soft magnetic powder content in the powder compact is, for example, more than 80 volume %, 85 volume % or more, 90 volume % or more, or 95 volume % or more, when the powder compact is taken as 100 volume %. The raw material powder may contain a lubricant.

[0061] 7 and 8, a reactor 1β of the second embodiment will be described. The reactor 1β of the second embodiment is different from the reactor 1α of the first embodiment in the shape of the magnetic core 8, the shape of the first holding member 5, and the shape of the second holding member 6.

[0062] As shown in FIG. 7 , the outer core portion 82 of this example includes a first end core portion 821, a second end core portion 822, and two side core portions 823 and 824. The two side core portions 823 and 824 are arranged to sandwich the winding portion 20. The side core portion 823 connects first ends of the first end core portion 821 and the second end core portion 822 in the second direction D2. The side core portion 824 connects second ends of the first end core portion 821 and the second end core portion 822 in the second direction D2. The shape of the outer core portion 82, in which the first end core portion 821, the second end core portion 822, and the two side core portions 823 and 824 are connected, is a rectangular ring when viewed from the third direction D3. Although not shown, the inner core portion of this example is connected to the central region of each of the first end core portion 821 and the second end core portion 822 in the second direction D2.

[0063] The magnetic core 8 of this example is an integrally molded product in which the inner core portion 81 and the outer core portion 82 are seamlessly formed, as in the first embodiment. The magnetic core 8 of this example is made of a molded body of a composite material.

[0064] As shown in FIGS. 7 and 8 , the first holding member 5 of this example includes a main body portion 50, a first protrusion portion 51, a second protrusion portion 52, and two side portions 55, 56. The two side portions 55, 56 are arranged to face each other. The side portion 55 is provided to extend in the first direction D1 from a first end portion of the main body portion 50 in the second direction D2. The side portion 55 is arranged between the side core portion 823 and the winding portion 20. The surface of the side portion 55 facing the winding portion 20 is an arcuate surface that follows the outer shape of the winding portion 20. The side portion 56 is provided to extend in the first direction D1 from a second end portion of the main body portion 50 in the second direction D2. The side portion 56 is arranged between the side core portion 824 and the winding portion 20. The surface of the side portion 56 facing the winding portion 20 is an arcuate surface that follows the outer shape of the winding portion 20. As shown in FIG. 8, for example, gaps 7 are provided between the side portion 55 and the winding portion 20 and between the side portion 56 and the winding portion 20 .

[0065] Similar to the first holding member 5, the second holding member 6 of this example includes a main body 60, a first protrusion, a second protrusion, and two side portions 65, 66. The first protrusion and the second protrusion are the same as the first protrusion 61 and the second protrusion 62 shown in Figures 2 and 3. The second holding member 6 of this example coincides with the first holding member 5 when rotated 180 degrees around an axis parallel to the second direction D2.

[0066] In this example, the first holding member 5 also has two protrusions, the first protrusion 51 and the second protrusion 52, so the number of objects to inspect for the formability of the protrusions is small. Even if the first holding member 5 has two protrusions, the first protrusion 51 corresponds to the first curved portion 43, and the second protrusion 52 corresponds to the second curved portion 44, so it is easy to increase the rigidity of the first protrusion 51 and the second protrusion 52. The first holding member 5 having the highly rigid first protrusion 51 and second protrusion 52 has excellent rigidity.

[0067] Similarly, because the second holding member 6 has only two protrusions, the first protrusion 61 and the second protrusion 62, the number of objects to be inspected for the formability of the protrusions is small. Even if the second holding member 6 has only two protrusions, the first protrusion 61 corresponds to the first curved portion 43, and the second protrusion 62 corresponds to the second curved portion 44, making it easy to increase the rigidity of the first protrusion 61 and the second protrusion 62. The second holding member 6 having the highly rigid first protrusion 61 and second protrusion 62 has excellent rigidity.

[0068] 9 to 13, a reactor 1γ of the third embodiment will be described. The reactor 1γ of the third embodiment includes two winding portions 20. The reactor 1γ of the third embodiment differs from the reactor 1α of the first embodiment in the number of winding portions 20, the shape of the magnetic core 8, the shape of the first holding member 5, and the shape of the second holding member 6.

[0069] The coil 2 of this example has two winding portions 20. The two winding portions 20 have the same configuration. The two winding portions 20 are composed of a single winding 3. Although not shown, first ends of both winding portions 20 are connected to each other. Each winding portion 20 is composed of a plurality of turns 4. In both winding portions 20, each turn 4 is composed of a first straight portion 41, a first curved portion 43, a second straight portion 42, and a second curved portion 44, which are arranged in this order around the axis of the winding portion 20, as shown in FIG. 12. The configuration of each winding portion 20 is similar to the configuration of the winding portion 20 described in embodiment 1.

[0070] The magnetic core 8 of this example includes two inner core portions 81 shown in Fig. 13 and an outer core portion 82 shown in Fig. 9. As in the first embodiment, the magnetic core 8 of this example is an integrally molded product in which the two inner core portions 81 and the outer core portion 82 are seamlessly joined. The magnetic core 8 of this example is made of a composite material molded body. For ease of understanding, the outer core portion 82 shown in Fig. 9 is not shown in Fig. 13.

[0071] The two inner core portions 81 have the same configuration. As shown in Fig. 13 , two recesses 810 are provided at both ends of each inner core portion 81. The two recesses provided at the first end portion of the inner core portion 81 correspond to the first protrusion 51 and the second protrusion 52 provided on the first retaining member 5. For convenience of explanation, Fig. 13 shows a state in which the first retaining member 5 is assembled to the first end portion of the inner core portion 81. The two recesses 810 provided at the second end portion of the inner core portion 81 correspond to the first protrusion 61 and the second protrusion 62 provided on the second retaining member 6 shown in Figs. 10 and 11 .

[0072] 9 , the outer core portion 82 of this example includes a first end core portion 821 and a second end core portion 822. A first end portion of each inner core portion 81 is connected to the first end core portion 821, and a second end portion of each inner core portion 81 is connected to the second end core portion 822. The shape of the magnetic core 8 in which the two inner core portions 81 and the outer core portion 82 are connected is a rectangular O-shape when viewed from the third direction D3.

[0073] As shown in FIGS. 11 and 12 , the first holding member 5 of this example includes a main body portion 50, a first protrusion 51, a second protrusion 52, and a side portion 55. Two through holes 50h are provided in the main body portion 50. The two through holes 50h have the same configuration. A first protrusion 51 and a second protrusion 52 are provided corresponding to each through hole 50h. In this example, two winding portions 20 are provided, and a first protrusion 51 and a second protrusion 52 are provided corresponding to each winding portion 20. Therefore, the first holding member 5 of this example includes two first protrusions 51 and two second protrusions 52. Even in this case, the number of protrusions provided for the first end of one winding portion 20 is two. In other words, no protrusions other than the first protrusion 51 and the second protrusion 52 are provided for the first end of one winding portion 20 to position that winding portion 20.

[0074] The side portion 55 is provided between the two through holes 50h. As shown in Fig. 9, the side portion 55 is disposed between the two winding portions 20. The surface of the side portion 55 facing the winding portion 20 is an arcuate surface that follows the outer shape of the winding portion 20. A gap 7 is provided between the side portion 55 and each winding portion 20, as shown in Fig. 12, for example.

[0075] Similar to the first holding member 5, the second holding member 6 of this example includes a main body 60, a first protrusion 61, a second protrusion 62, and a side portion 65. The second holding member 6 of this example coincides with the first holding member 5 when rotated 180° around an axis parallel to the second direction D2.

[0076] In this example, although reactor 1γ has two winding portions 20, first holding member 5 has only two protrusions, first protrusion 51 and second protrusion 52, provided on the first end of each winding portion 20, and therefore the number of objects to inspect for the formability of the protrusions is small. Even though there are only two protrusions provided on the first end of each winding portion 20, first protrusion 51 corresponds to first curved portion 43 and second protrusion 52 corresponds to second curved portion 44, which makes it easy to increase the rigidity of first protrusion 51 and second protrusion 52. First holding member 5 having highly rigid first protrusion 51 and second protrusion 52 has excellent rigidity.

[0077] Similarly, because the second holding member 6 has two protrusions, the first protrusion 61 and the second protrusion 62, provided on the second end of one winding portion 20, the number of objects to inspect for the formability of the protrusions is small. Even though there are two protrusions provided on the second end of one winding portion 20, the first protrusion 61 corresponds to the first curved portion 43 and the second protrusion 62 corresponds to the second curved portion 44, which makes it easy to increase the rigidity of the first protrusion 61 and the second protrusion 62. The second holding member 6 having the first protrusion 61 and the second protrusion 62 with high rigidity has excellent rigidity.

[0078] Fourth Embodiment Converter / Power Conversion Apparatus The above-described reactors 1α, 1β, and 1γ can be used in applications that satisfy the following energization conditions. The energization conditions include, for example, a maximum DC current of approximately 100 A to 1000 A, an average voltage of approximately 100 V to 1000 V, and an operating frequency of approximately 5 kHz to 100 kHz. The above-described reactors 1α, 1β, and 1γ are typically used as components of a converter installed in a vehicle such as an electric vehicle or a hybrid vehicle, or as components of a power conversion apparatus that includes this converter.

[0079] As shown in Fig. 14 , a vehicle 1200 such as a hybrid vehicle or an electric vehicle includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and a motor 1220 that is driven by power supplied from the main battery 1210 and used for traveling. The motor 1220 is typically a three-phase AC motor that drives wheels 1250 during traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 includes an engine 1300 in addition to the motor 1220. In Fig. 14 , the charging point of the vehicle 1200 is an inlet, but a plug may also be provided.

[0080] The power conversion device 1100 includes a converter 1110 connected to a main battery 1210, and an inverter 1120 connected to the converter 1110 and performing mutual conversion between direct current and alternating current. The converter 1110 shown in this example boosts the input voltage of the main battery 1210, which is approximately 200 V or more and 300 V or less, to approximately 400 V or more and 700 V or less, when the vehicle 1200 is running, and supplies power to the inverter 1120. During regeneration, the converter 1110 reduces the input voltage output from the motor 1220 via the inverter 1120 to a direct current voltage suitable for the main battery 1210, and charges the main battery 1210. The input voltage is a direct current voltage. When the vehicle 1200 is running, the inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC and supplies it to the motor 1220, and when regenerating, it converts the AC output from the motor 1220 into DC and outputs it to the converter 1110.

[0081] As shown in FIG. 15 , converter 1110 includes multiple switching elements 1111, a drive circuit 1112 that controls the operation of switching elements 1111, and a reactor 1115, and converts the input voltage by repeatedly turning the elements on and off. Here, the conversion of the input voltage means boosting or bucking the voltage. Power devices such as field-effect transistors and insulated gate bipolar transistors are used for switching elements 1111. Reactor 1115 utilizes the properties of a coil that hinders changes in current flowing through the circuit, and has the function of smoothing changes when the current increases or decreases due to switching operations. Reactor 1115 includes reactors 1α, 1β, and 1γ described above.

[0082] In addition to converter 1110, vehicle 1200 is equipped with a power supply converter 1150 connected to main battery 1210, and an auxiliary power supply converter 1160 connected to main battery 1210 and sub-battery 1230, which serves as a power source for auxiliary equipment 1240, and converts the high voltage of main battery 1210 to a low voltage. Converter 1110 typically performs DC-DC conversion, while power supply converter 1150 and auxiliary power supply converter 1160 perform AC-DC conversion. Some power supply converters 1150 perform DC-DC conversion. Reactors having the same configuration as reactors 1α, 1β, and 1γ described above, but with the size, shape, etc. modified as appropriate, can be used as the reactors of power supply converter 1150 and auxiliary power supply converter 1160. Furthermore, the reactors 1α, 1β, and 1γ described above can also be used in converters that convert input power, such as converters that only step up voltage or converters that only step down voltage.

[0083] 1α, 1β, 1γ Reactor 2 Coil 20 Winding portion 21 First end surface 22 Second end surface 3 Winding 4 Turn 41 First straight portion 42 Second straight portion 43 First curved portion 44 Second curved portion 5 First holding member 50 Main body portion 50h Through hole 51 First protrusion 52 Second protrusion 55, 56 Side portion 6 Second holding member 60 Main body portion 60h Through hole 61 First protrusion 62 Second protrusion 65, 66 Side portion 7 Air gap 8 Magnetic core 81 Inner core portion 810 Recess 82 Outer core portion 821 First end core portion 822 Second end core portion 823, 824 Side core portions L1, L2 Length D1 First direction, D2 Second direction, D3 Third direction REFERENCE SIGNS LIST 1100 Power conversion device, 1110 Converter, 1111 Switching element 1112 Drive circuit, 1115 Reactor, 1120 Inverter 1150 Converter for power supply device, 1160 Converter for auxiliary power supply 1200 Vehicle, 1210 Main battery, 1220 Motor 1230 Sub-battery, 1240 Auxiliary devices, 1250 Wheels, 1300 Engine

Claims

1. A reactor comprising: a coil having a winding portion composed of a plurality of turns of wire; a first retaining member arranged to face a first end face of the winding portion; and a second retaining member arranged to face a second end face of the winding portion, each of the plurality of turns being composed of a first straight portion, a first curved portion, a second straight portion, and a second curved portion arranged in that order around the axis of the winding portion, each of the first retaining member and the second retaining member having two protrusions for positioning the winding portion, the two protrusions being composed of a first protrusion tangent to at least a portion of the first curved portion, and a second protrusion tangent to at least a portion of the second curved portion.

2. The reactor according to claim 1, wherein each of the first curved portion and the second curved portion has a semicircular shape.

3. The reactor according to claim 1 or 2, wherein each of the first protrusion and the second protrusion has a shape that conforms to the inner circumferential shape of the winding portion.

4. A reactor according to any one of claims 1 to 3, wherein the coil is an edgewise coil made of rectangular wire.

5. A reactor according to any one of claims 1 to 4, wherein a first length of each of the first straight portion and the second straight portion is longer than a second length between the first straight portion and the second straight portion.

6. A converter comprising a reactor according to any one of claims 1 to 5.

7. A power conversion device comprising the converter according to claim 6.

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