Reactor, magnetic core, converter, and power conversion device

Abstract

A reactor is provided with: a magnetic core having a core part configured in a corner column shape; and a coil having a first winding portion disposed on the outer periphery of the core portion and a second winding portion disposed on the outer periphery of the first winding portion, the first winding portion comprising a first winding wire wound in a spiral shape along the outer peripheral surface of the core portion, and the second winding portion comprising a second winding wire wound in a spiral shape along the outer peripheral surface of the core portion. The second winding wire is wound along the outer peripheral surface of the first winding part, the first winding wire and the second winding wire are continuous winding wires, the number of turns of the first winding part is smaller than the number of turns of the second winding part, the outer peripheral surface of the core part includes a first plane, the first plane has a plurality of groove parts arranged in the direction along the axis of the core part, and the groove parts are arranged in the first plane. A portion of the first winding wire in each turn of the first winding portion is disposed in each of the plurality of slot portions.

Description

Technical Field

[0001] The present invention relates to a reactor, a magnetic core, a converter and a power conversion device. This application claims priority based on Japanese Patent Application No. 2022-105129 filed in Japan on June 29, 2022, and incorporates all the contents described in the aforementioned Japanese application. Background Art

[0002] The reactor of Patent Document 1 comprises a coil and a magnetic core. The coil comprises a pair of winding parts formed by winding a winding wire into a spiral shape. The shape of each winding part is an angular tube shape. The magnetic core comprises a pair of inner core parts and a pair of outer core parts. Each inner core part is arranged inside each winding part. The shape of each inner core part is an angular column shape. Each outer core part is arranged outside the two winding parts. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2013-219318 Summary of the invention Problems to be solved by the invention

[0004] The reactor of the present invention comprises: a magnetic core having a core portion configured in a prism shape; and The coil includes a first winding portion disposed on the outer periphery of the core portion and a second winding portion disposed on the outer periphery of the first winding portion. The first winding portion is composed of a first winding wire, and the first winding wire is wound in a spiral shape along the outer peripheral surface of the core. The second winding portion is composed of a second winding wire, and the second winding wire is wound along the outer peripheral surface of the first winding portion. The first winding wire and the second winding wire are continuous winding wires, The number of turns of the first winding portion is less than the number of turns of the second winding portion, The outer peripheral surface of the core includes a first plane having a plurality of grooves arranged in a direction along the axis of the core. A portion of the first winding wire in each turn of the first winding portion is arranged in each of the plurality of groove portions.

[0005] The magnetic core of the present invention, Having a prism-shaped core, The outer peripheral surface of the core portion includes a first plane having a plurality of grooves arranged in a direction along the axis of the core portion.

[0006] A converter according to the present invention includes the reactor according to the present invention.

[0007] A power conversion device according to the present invention includes the converter according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic perspective view showing the reactor according to the first embodiment. Figure 2 This is a schematic exploded perspective view showing the reactor according to the first embodiment. Figure 3 yes Figure 1 III-III sectional view. Figure 4 yes Figure 3 Magnified view of area A. Figure 5 This is an enlarged view showing another example of the slot portion and the first winding wire in the reactor according to the first embodiment. Figure 6 This is an enlarged view showing another example of the slot portion and the first winding wire in the reactor according to the first embodiment. Figure 7 This is an enlarged view showing the slot portion and the first winding wire in the reactor according to the second embodiment. Figure 8 This is an enlarged view showing a slot portion and a first winding wire in the reactor according to the third embodiment. Fig. 9 This is an enlarged view showing a slot portion and a first winding wire in the reactor according to the fourth embodiment. Fig.10 This is an enlarged view showing the slot portion and the first winding wire in the reactor according to the fifth embodiment. Fig.11 This is an enlarged view showing another example of the slot portion and the first winding wire in the reactor according to the fifth embodiment. Fig.12 The diagram schematically shows the configuration of a power supply system of a hybrid vehicle. Fig.13 This is a circuit diagram showing an example of a power conversion device including a converter. DETAILED DESCRIPTION

[0009] [Problems to be Solved by the Invention] It is hoped that not only the heat dissipation can be easily improved, but also the size increase of the reactor and the reduction of the magnetic circuit area can be suppressed when the number of turns is increased.

[0010] The reactor of Patent Document 1 is manufactured as follows. A pair of windings is prepared. Each inner core is inserted into the interior of each winding. The two inner cores and the two outer cores are fixed. In order to insert each inner core into the interior of each winding, a gap is provided between the inner circumference of each winding and the outer circumference of each inner core. Due to the provision of the gap, it is difficult to improve the heat dissipation of the inner core.

[0011] In order to increase the number of turns, it is possible to consider setting each winding portion to a double-layer structure on the inside and outside instead of a single-layer structure. When the cross-sectional area of ​​the inner core portion is constant, the inductor having a winding portion with a double-layer structure will be larger than the inductor having a winding portion with a single-layer structure. The so-called cross-sectional area of ​​the inner core portion is the area of ​​the cross section orthogonal to the direction along the axis of the inner core portion. When the outer diameter of the winding portion is constant, the cross-sectional area of ​​the inner core portion of the inductor having a double-layer structure winding portion becomes smaller than that of the inductor having a single-layer structure winding portion, so the magnetic path area is reduced.

[0012] One object of the present invention is to provide a reactor that is not only easy to improve heat dissipation, but also easy to suppress enlargement and reduction of magnetic circuit area when the number of turns is increased. Another object of the present invention is to provide a magnetic core that can construct a reactor that is not only easy to improve heat dissipation, but also easy to suppress enlargement and reduction of magnetic circuit area when the number of turns is increased. Another object of the present invention is to provide a converter having the above-mentioned reactor and a power conversion device having the above-mentioned converter.

[0013] [Effects of the Invention] The reactor of the present invention is not only easy to improve heat dissipation, but also easy to suppress enlargement and reduction of magnetic circuit area when the number of turns is increased. The magnetic core of the present invention is easy to construct a reactor that is not only easy to improve heat dissipation, but also easy to suppress enlargement and reduction of magnetic circuit area when the number of turns is increased. The converter of the present invention and the power conversion device of the present invention are not large-scale and have excellent heat dissipation.

[0014] <Description of Embodiments of the Invention> First, embodiments of the present invention will be described by way of examples.

[0015] (1) A reactor according to one aspect of the present invention includes: a magnetic core having a core portion configured in a prism shape; and The coil includes a first winding portion disposed on the outer periphery of the core portion and a second winding portion disposed on the outer periphery of the first winding portion. The first winding portion is composed of a first winding wire, and the first winding wire is wound in a spiral shape along the outer peripheral surface of the core. The second winding portion is composed of a second winding wire, and the second winding wire is wound along the outer peripheral surface of the first winding portion. The first winding wire and the second winding wire are continuous winding wires, The number of turns of the first winding portion is less than the number of turns of the second winding portion, The outer peripheral surface of the core includes a first plane having a plurality of grooves arranged in a direction along the axis of the core. A portion of the first winding wire in each turn of the first winding portion is arranged in each of the plurality of groove portions.

[0016] The structure of (1) described above is easier to improve heat dissipation than conventional reactors. In the structure of (1), the first winding portion is along the outer peripheral surface of the core, and a portion of the first winding wire in each turn of the first winding portion is arranged in each of the plurality of grooves provided in the core. That is, the structure of (1) described above is easier to increase the contact area between the first winding wire and the core. On the other hand, conventional reactors have a gap between the inner peripheral surface of the winding portion and the outer peripheral surface of the core. That is, the winding portion and the core of the conventional reactor are not in contact. Therefore, the structure of (1) described above is easier to transfer the heat of the coil to the core than conventional reactors.

[0017] In the structure of (1) above, the number of turns can be increased by providing the coil with the first winding portion. Therefore, the structure of (1) above is excellent in inductance.

[0018] In the structure of (1) above, a portion of the first winding wire in each turn of the first winding portion is arranged in each of the plurality of grooves provided in the core portion, so it is difficult to increase the size compared to a case where no grooves are provided. In the case where the outer diameter of the second winding portion is constant, in the structure of (1) above, the cross-sectional area of ​​the core portion is reduced by only the amount of the cross-sectional area of ​​the groove portion, so it is easy to suppress the reduction of the magnetic path area.

[0019] The structure (1) is easy to manufacture because the first winding portion can be manufactured by winding the first winding wire along the outer circumference of the core portion while following the groove portion. That is, when manufacturing the first winding portion, the groove portion can be used as a guide portion for the first winding wire.

[0020] (2) In the reactor of (1) above, it is also possible to have: The outer peripheral surface of the core has a spiral groove arranged coaxially with the core. Each of the plurality of groove portions constitutes a portion of the spiral groove, The first winding wire in all turns of the first winding portion is arranged in the spiral groove.

[0021] The structure of (2) above can easily increase the contact area between the first winding wire and the core, so that the heat of the first winding wire can be easily transferred to the core. Therefore, the structure of (2) above can easily improve the heat dissipation.

[0022] (3) In the reactor of (1) or (2), it is also possible to have: The depth of each of the plurality of grooves is equal to the length of the first winding wire in a cross section along the depth direction.

[0023] Compared with the structure (4) described later, the structure (3) described above is easier to transfer the heat of the first winding wire to the core. The reason is that the contact area between the first winding wire and the core in the structure (3) described above is easier to be larger than that in the structure (4) described later. In addition, compared with the structure (4) described later, the heat of the second winding wire is also easier to be transferred to the core in the structure (3) described above. The reason is as follows. In the structure (3) described above, the first winding wire arranged in the groove does not protrude from the groove. On the other hand, in the structure (4) described later, a part of the first winding wire arranged in the groove protrudes from the groove. Therefore, the contact area between the second winding wire and the ridge of the core in the structure (3) described above is easier to be larger than that in the structure (4) described later. The so-called ridge is the part between the adjacent grooves in the outer peripheral surface of the core in the direction along the axis. Therefore, the structure (3) described above is easier to transfer the heat of the first winding wire and the second winding wire to the core, so it is excellent in heat dissipation.

[0024] (4) In the reactor of (1) or (2), it is also possible to have: The depth of each of the plurality of grooves is smaller than the length of the first winding wire in a cross section along the depth direction.

[0025] The structure (4) is easier to manufacture than the structure (3) because, in the structure (4), the portion of the first winding wire protruding from the groove and the step of the ridge can be easily used as a guide when winding the second winding wire during the manufacturing process.

[0026] (5) In the reactor of (1) or (2), it is also possible to have: The depth of each of the plurality of grooves is greater than the length of the first winding wire in a cross section along the depth direction.

[0027] The structure of (5) is similar to the structure of (3) and is more likely to transfer the heat of the first winding wire and the second winding wire to the core than the structure of (4). Therefore, the structure of (5) is excellent in heat dissipation.

[0028] (6) In any one of the reactors described in (1) to (5), it is also possible that: The first winding wire and the second winding wire are flat wires, Each of the plurality of grooves cut along the axis of the core has a rectangular cross-sectional shape.

[0029] The structure of (6) above makes it easy to arrange the first winding wire in the groove portion, so that the first winding wire and the groove portion are easily in contact. Therefore, the structure of (6) above makes it easy to transfer the heat of the first winding wire to the core portion.

[0030] (7) In the reactor of (6) above, it is also possible to have: The first winding portion and the second winding portion are formed by flat-winding the flat wire.

[0031] The above-mentioned structure (7) and the structure (8) described later make it easier to bend the rectangular wire, and thus it is easier to manufacture the first winding portion and the second winding portion.

[0032] (8) In the reactor of (6) above, it is also possible to have: The first winding portion and the second winding portion are formed by flat-winding the flat wire.

[0033] When the length of the winding portion along the axial direction is constant, the structure (8) can easily increase the number of turns of the first winding portion and the second winding portion compared with the structure (7). When the number of turns of the first winding portion and the second winding portion is constant, the structure (8) can easily shorten the length of the first winding portion and the second winding portion along the axial direction compared with the structure (7). Therefore, the structure (8) can be more compact than the structure (7).

[0034] (9) In any one of the reactors described in (1) to (8), it is also possible that: The core is in the shape of a quadrangular column. The first winding portion and the second winding portion are in a quadrangular cylindrical shape.

[0035] The structure (9) is easy to manufacture because it is easy to wind the first winding wire along the outer peripheral surface of the core during the manufacturing process. Compared with the case where the second winding portion is a circular cylinder with the same cross-sectional area, the structure (9) is easy to increase the contact area between the second winding portion and the object where the reactor is installed. Therefore, the structure (9) is easy to transfer the heat of the second winding portion to the object where the reactor is installed. Moreover, the structure (9) is easy to stably install the second winding portion on the object where the reactor is installed.

[0036] (10) In any one of the reactors described in (1) to (9), it is also possible that: The core has: a core body portion mainly made of a magnetic material; and an insulating portion provided along the outer peripheral surface of the core main body portion, The plurality of grooves are provided on the insulating portion

[0037] Compared with a case where the core portion is composed of only a core body portion without an insulating portion, the structure of (10) can easily improve the insulation between the core body portion and the coil by the insulating portion.

[0038] (11) Another aspect of the present invention relates to a magnetic core having a prism-shaped core portion. The outer peripheral surface of the core portion includes a first plane having a plurality of grooves arranged in a direction along the axis of the core portion.

[0039] The structure of (11) above makes it easy to construct a reactor that not only improves heat dissipation but also suppresses enlargement and reduction in magnetic path area when the number of turns is increased, for the reasons explained in the structure of (1) above.

[0040] (12) In the magnetic core of (11) above, it is also possible to have: The outer peripheral surface of the core has a spiral groove arranged coaxially with the core. Each of the plurality of groove portions constitutes a portion of the spiral groove.

[0041] The structure of (11) above can easily construct a reactor with improved heat dissipation properties for the reasons described in the structure of (2) above.

[0042] (13) A converter according to another aspect of the present invention includes any one of the reactors described in (1) to (10).

[0043] Since the converter includes the reactor, it does not increase in size and has excellent heat dissipation properties.

[0044] (14) Another aspect of the present invention relates to a power conversion device including the converter of (13) above.

[0045] Since the power conversion device includes the converter, it does not increase in size and has excellent heat dissipation properties.

[0046] <<Details of Embodiments of the Invention>> The following describes the details of the embodiments of the present invention with reference to the accompanying drawings. The same reference numerals in the drawings represent the same names. The sizes of the components shown in the drawings are for the purpose of clarifying the description and do not necessarily represent the actual dimensional relationships.

[0047] Implementation Method 1 [Reactor] Reference Figures 1 to 6 The reactor 1 according to the first embodiment will be described. The reactor 1 includes a coil 2 and a magnetic core 3. Figure 2 As shown, the magnetic core 3 has a core portion 30. The core portion 30 is in the shape of a prism. The coil 2 has a first winding portion 2i and a second winding portion 2e. The first winding portion 2i is arranged on the outer periphery of the core portion 30. The second winding portion 2e is arranged on the outer periphery of the first winding portion 2i. One of the characteristics of the reactor 1 of the present embodiment is that the following requirements (A) to (C) are satisfied. (A) Figure 2As shown, the outer peripheral surface of the core 30 includes a first plane 35. The first plane 35 has a plurality of grooves 36 arranged in a direction along the axis of the core 30. (B) The first winding portion 2i is composed of the first winding wire 21. The first winding wire 21 is wound in a spiral shape along the outer peripheral surface of the core 30. (C) Figure 3 and Figure 4 As shown, a portion of the first winding wire 21 in each turn of the first winding portion 2 i is arranged in each of the plurality of groove portions 36 .

[0048] [Magnetic core] Figure 2 The magnetic core 3 of the present embodiment shown in the figure comprises a first intermediate core 31f, a second intermediate core 31s, a first end core 33f and a second end core 33s. The core 30 of the present embodiment constitutes each of the first intermediate core 31f and the second intermediate core 31s. The core 30 of the present embodiment, namely the first intermediate core 31f and the second intermediate core 31s, is different from the embodiment 5 in that it does not have the reference Fig.10 , Fig.11 The insulating portion 30b described later is composed of a core body portion 30a mainly composed of a magnetic material. The core body portion 30a is composed of a molded body or a laminated body described later. The first end core portion 33f and the second end core portion 33s are each composed of a molded body or a laminated body independent of the first intermediate core portion 31f and the second intermediate core portion 31s.

[0049] The first intermediate core 31f, the second intermediate core 31s, the first end core 33f and the second end core 33s are annularly combined. The first end face of the first intermediate core 31f and the inner end face of the first end core 33f face each other. The second end face of the first intermediate core 31f and the inner end face of the second end core 33s face each other. The first end face of the second intermediate core 31s and the inner end face of the first end core 33f face each other. The second end face of the second intermediate core 31s and the inner end face of the first end core 33f face each other. The spacer described later may also be arranged between the first intermediate core 31f and the first end core 33f, between the first intermediate core 31f and the second end core 33s, between the second intermediate core 31s and the first end core 33f, and between the second intermediate core 31s and the second end core 33s.

[0050] The first intermediate core portion 31f and the second intermediate core portion 31s have the same structure. The first end core portion 33f and the second end core portion 33s have the same structure. The first intermediate core portion 31f and the first end core portion 33f will be described below as representatives.

[0051] The first intermediate core 31f is in the shape of a prism. The first intermediate core 31f of this embodiment is in the shape of a quadrangular prism. The four corners of the quadrangular prism are rounded. That is, the outer peripheral surface of the first intermediate core 31f excluding the first end surface and the second end surface is composed of four planes and four corners.

[0052] like Figure 2 As shown, at least one of the four planes is the above-mentioned first plane 35. For example, one plane may be the first plane 35, and the remaining three planes may be the second plane. The so-called second plane is different from the first plane 35 and is a flat surface without a groove portion 36. In this case, the plane facing the object of setting the reactor 1 among the four planes may also be the first plane 35. For example, two of the four planes may be the first plane 35, and the remaining two planes may be the second plane. In this case, the first plane 35 and the second plane may also be arranged alternately in the direction around the axis of the first intermediate core 31f. That is, the first planes 35 may also be arranged at positions facing each other. For example, all four planes may also be the first plane 35. In the present embodiment, all four planes are the first plane 35.

[0053] The outer circumference of the first intermediate core 31f of the present embodiment has a spiral groove 37 coaxially arranged with the first intermediate core 31f. As in the present embodiment, when the outer circumference of the first intermediate core 31f has the spiral groove 37, each of the four corners also has a plurality of grooves 36 arranged in the direction along the above axis. Each of the plurality of grooves 36 arranged on each first plane 35 and each of the plurality of grooves 36 arranged on each corner constitutes a part of the spiral groove 37. The grooves 36 of the adjacent first planes 35 and corners are continuous with each other. If only the first plane 35 or the corner is considered, the grooves 36 are independent of each other, so the number of grooves 36 is plural. If the entire circumference of the outer circumference of the first intermediate core 31f is considered, the spiral groove 37 is continuous, so the number of spiral grooves 37 is one. The spiral grooves 37 of the present embodiment are staggered by 1 / 4 pitch every 1 / 4 of the circumference.

[0054] The cross-sectional shape of each groove portion 36 cut along the axis can be appropriately selected according to the cross-sectional shape of the first winding wire 21. The cross-sectional shape in the present embodiment is a rectangle.

[0055] like Figure 3 and Figure 4As shown, in the present embodiment, the width of each groove portion 36 is substantially the same as the width of the first winding wire 21 which is a flat wire. The width of the groove portion 36 is the length along the direction orthogonal to both the extending direction of the groove portion 36 and the depth direction of the groove portion 36. By making the width of each groove portion 36 substantially the same as the width of the first winding wire 21, the contact area between the first winding wire 21 arranged in each groove portion 36 and the first intermediate core portion 31f is easily increased. Therefore, the heat of the first winding wire 21 is easily transferred to the first intermediate core portion 31f. Therefore, the heat dissipation of the reactor 1 is excellent.

[0056] like Figure 4 As shown, the depth of each groove 36 may be the same as the length of the first winding wire 21 in the cross section along the axis in the direction of the depth, that is, the same as the thickness of the first winding wire 21 as the coated flat wire in this embodiment. Figure 5 As shown, the depth of each groove 36 may also be smaller than the thickness of the first winding wire 21. Figure 6 As shown, the depth of each groove 36 may also be greater than the thickness of the first winding wire 21 .

[0057] Figure 4 and Figure 6 The contact area between the first winding wire 21 and the first intermediate core 31f in the example shown is Figure 5 The example shown is easier to enlarge. Figure 4 and Figure 6 The example shown is similar to Figure 5 Compared with the example shown, it is easy to transfer the heat of the first winding wire 21 to the first intermediate core 31f. Figure 4 and Figure 6 In the example shown, the first winding wire 21 arranged in the groove portion 36 does not protrude from the groove portion 36. Figure 5 In the example shown, a portion of the first winding wire 21 disposed in the groove portion 36 protrudes from the groove portion 36. Therefore, Figure 4 and Figure 6 In the example shown, the contact area between the second winding wire 22 and the ridge portion 38 of the first intermediate core portion 31f is about Figure 5 The example shown is relatively easy to be enlarged. The ridge portion 38 is a portion between the groove portions 36 of adjacent turns along the above-mentioned axis of the spiral groove 37 in the outer peripheral surface of the first intermediate core portion 31f. Therefore, Figure 4 and Figure 6 The example shown is similar to Figure 5 Compared with the example shown, the heat of the second winding wire 22 is also easily transferred to the first intermediate core 31f. Figure 4 and Figure 6 The example shown is similar to Figure 5 Compared with the example shown, it is easy to make the outer peripheral surface of the second winding portion 2e flush. Figure 4 and Figure 6 The example shown is similar to Figure 5 Compared with the example shown, it is easy to make the outer peripheral surface of the second winding portion 2e come into surface contact with the object to be set. An example of the object to be set is the inner surface of the cooling base or the shell. Figure 4 and Figure 6 The example shown is similar to Figure 5 Compared with the example shown, it is also easy to transfer the heat of the second winding wire 22 to the object to be installed. Figure 5 In the example shown, Figure 4 and Figure 6 Compared with the example shown, when the second winding wire 22 is wound during the manufacturing process, the portion of the first winding wire 21 protruding from the groove portion 36 and the step of the ridge portion 38 are easily used as guides. Figure 5 The example shown is similar to Figure 4 and Figure 6 The example shown is relatively easy to manufacture.

[0058] The intervals between the grooves 36 of the adjacent turns in the spiral groove 37 in the direction along the above-mentioned axis can be appropriately selected. The intervals between the above-mentioned grooves 36 are the shortest distances between the openings of the above-mentioned grooves 36. The intervals between the above-mentioned grooves 36 can be the same as the length of the grooves 36 along the above-mentioned axis, or can be smaller or larger than the length of the grooves 36 along the above-mentioned axis. The smaller the intervals between the above-mentioned grooves 36, the more turns the first winding portion 2i has. The larger the intervals between the above-mentioned grooves 36, the fewer turns the first winding portion 2i has. Therefore, it is easy to ensure the magnetic circuit area. Moreover, the number of turns of the second winding portion 2e that contacts the ridge portion 38 of the first intermediate core portion 31f tends to increase. Therefore, the heat of the second winding wire 22 is easily transferred to the first intermediate core portion 31f.

[0059] The first end core portion 33f has a columnar shape. The first end core portion 33f of the present embodiment has a columnar shape having a substantially dome-shaped upper surface and a lower surface.

[0060] The first intermediate core portion 31f and the first end core portion 33f are formed of a composite material molded body, a powder molded body, or a laminated body.

[0061] The molded body of the composite material is a molded body formed by dispersing soft magnetic powder in resin. The molded body of the composite material is obtained by filling a flowable raw material in which soft magnetic powder is dispersed in an uncured resin into a mold and curing the resin. The molded body of the composite material having a plurality of grooves 36 or spiral grooves 37 can be made by transfer of the mold. The molded body of the composite material can easily adjust the content of the soft magnetic powder in the resin. Therefore, the molded body of the composite material can easily adjust the magnetic properties. Moreover, compared with the pressed powder molded body, the molded body of the composite material is easy to form even a complex shape. An example of the content of the soft magnetic powder in the molded body of the composite material is 20 volume % or more and 80 volume % or less. An example of the content of the resin in the molded body of the composite material is 20 volume % or more and 80 volume % or less. These contents are values ​​when the molded body of the composite material is 100 volume %.

[0062] A powder compact is a compact formed by compressing soft magnetic powder. The powder compact is obtained by filling a cavity with soft magnetic powder and pressurizing the soft magnetic powder in the cavity with a punch. A powder compact provided with a plurality of grooves 36 can be made by transfer of at least one of the cavity and the punch. Compared with a compact of a composite material, a powder compact can increase the proportion of soft magnetic powder in the core 30. Therefore, it is easy for a powder compact to improve magnetic properties. As a magnetic property, it is relative magnetic permeability or saturation magnetic flux density. In addition, compared with a compact of a composite material, a powder compact has a large amount of soft magnetic powder, so it has excellent heat dissipation. An example of the content of magnetic powder in a powder compact is 85% by volume or more and 99% by volume or less. This content is a value when the powder compact is 100% by volume.

[0063] The particles constituting the soft magnetic powder are soft magnetic metal particles, coated particles or soft magnetic non-metal particles. The coated particles may also include soft magnetic metal particles and an insulating coating layer disposed on the periphery of the soft magnetic metal particles. The soft magnetic metal is pure iron or an iron-based alloy. An example of an iron-based alloy is a Fe (iron)-Si (silicon) alloy or a Fe-Ni (nickel) alloy. An example of an insulating coating layer is a phosphate. An example of a soft magnetic non-metal is a ferrite.

[0064] An example of the resin of the composite material molded body is a thermosetting resin or a thermoplastic resin. An example of a thermosetting resin is an epoxy resin, a phenol resin, a silicone resin or a polyurethane resin. An example of a thermoplastic resin is a polyphenylene sulfide resin, a polyamide resin, a liquid crystal polymer, a polyimide resin or a fluororesin. An example of a polyamide resin is nylon 6, nylon 66 or nylon 9T.

[0065] The composite material molded body may also contain fillers. An example of a filler is alumina or silica. The filler helps to improve heat dissipation and electrical insulation.

[0066] The content of soft magnetic powder in the molded body of the composite material and the content of soft magnetic powder in the pressed powder molded body are regarded as equivalent to the area ratio of the soft magnetic powder on the cross section of the molded body. The content of soft magnetic powder in the molded body is calculated as follows. The cross section of the molded body is observed with an SEM (scanning electron microscope) to obtain an observation image. The cross section of the molded body is an arbitrary cross section. The magnification of the SEM is greater than 200 times and less than 500 times. The number of observation images obtained is more than 10. The total area of ​​all observation images is 0.1cm 2 The above. One observation image can be obtained for a cross section, or multiple observation images can be obtained for a cross section. Image processing is performed on each observation image obtained to extract the contour of the particles. As an example of image processing, binarization processing is performed. The area ratio of the soft magnetic particles in each observation image is calculated, and the average value of the area ratio is calculated. The average value is regarded as the content of the soft magnetic powder.

[0067] The laminate is formed by laminating a plurality of magnetic thin plates. The magnetic thin plates have an insulating coating. The magnetic thin plates may be, for example, electromagnetic steel plates. The laminate having a plurality of grooves 36 or spiral grooves 37 can be produced by laminating a plurality of magnetic thin plates having different areas in a direction along the thickness of the magnetic thin plates.

[0068] The first intermediate core portion 31f, the second intermediate core portion 31s, the first end core portion 33f, and the second end core portion 33s of the present embodiment are formed of a molded body of a composite material.

[0069] (Spacer) The spacer is formed of a member formed of a material having a lower relative magnetic permeability than the first intermediate core portion 31f, the second intermediate core portion 31s, the first end core portion 33f, and the second end core portion 33s. An example of a material for the spacer is the above-mentioned ceramic or resin.

[0070] [Coil] Figure 2 The coil 2 of the present embodiment shown has a first coil 2f and a second coil 2s. The first coil 2f and the second coil 2s may be connected to each other or not. The first winding portion 2i and the second winding portion 2e are respectively provided on the first coil 2f and the second coil 2s. The first winding portion 2i of the first coil 2f is arranged on the outer periphery of the first intermediate core portion 31f. The second winding portion 2e of the first coil 2f is arranged on the outer periphery of the first winding portion 2i of the first coil 2f. For the convenience of description, Figure 2The second winding portion 2e of the first coil 2f is indicated by a double-dotted line. The first winding portion 2i of the second coil 2s is arranged on the outer periphery of the second intermediate core portion 31s. The second winding portion 2e of the second coil 2s is arranged on the outer periphery of the first winding portion 2i of the second coil 2s. The number of turns is increased by having the first winding portion 2i of the first coil 2f and the second coil 2s. Therefore, the inductance of the reactor 1 is excellent. The first winding portion 2i and the second winding portion 2e of the first coil 2f have the same structure as the first winding portion 2i and the second winding portion 2e of the second coil 2s. The following description is representative of the first winding portion 2i and the second winding portion 2e of the first coil 2f.

[0071] The first winding portion 2i is in the shape of a square tube. The corners of the first winding portion 2i are rounded. The first winding portion 2i is composed of a first winding wire 21. The first winding wire 21 is wound in a spiral shape along the outer peripheral surface of the first intermediate core 31f. The first winding portion 2i in the shape of a square tube is easy to manufacture because it is easy to wind the first winding wire 21 along the outer peripheral surface of the first intermediate core 31f during the manufacturing process. The trajectory of each turn of the first winding wire 21 is along each groove portion 36. The first winding wire 21 is arranged in the spiral groove 37. Therefore, it is easy to transfer the heat of the first winding wire 21 to the first intermediate core 31f. Therefore, the heat dissipation of the reactor 1 is excellent. The number of turns of the first winding portion 2i is the same as the number of turns of the spiral groove 37. The number of turns of the first winding portion 2i is less than the number of turns of the second winding portion 2e. By reducing the number of turns of the first winding portion 2i, the number of turns of the spiral groove 37 is also reduced. Therefore, the reduction in the magnetic path area can be suppressed. The pitch of the first winding portion 2i can be selected appropriately. The pitch is the interval between turns along the width of the first winding wire 21. The pitch can be the same as the width of the first winding wire 21, or smaller or larger than the width of the first winding wire 21.

[0072] The second winding portion 2e is in the shape of a square tube. The corners of the second winding portion 2e are rounded. By making the second winding portion 2e in the shape of a square tube, it is easy to increase the contact area between the second winding portion 2e and the object to be set, compared with the case where the second winding portion 2e is in the shape of a circular tube with the same cross-sectional area. Therefore, the heat of the second winding portion 2e is easily transferred to the object to be set. Moreover, it is easy to stably set the second winding portion 2e on the object to be set. The second winding portion 2e is composed of a second winding wire 22. The second winding wire 22 is wound along the outer peripheral surface of the first winding portion 2i and the first intermediate core portion 31f. The second winding wire 22 is a winding wire continuous with the first winding wire 21. That is, the second winding wire 22 is a winding wire that has no joint with the first winding wire 21. There is substantially no gap formed between the turns of the second winding portion 2e. Adjacent turns of the second winding portion 2e are in contact with each other. Since the number of turns of the second winding portion 2e is greater than that of the first winding portion 2i, a portion of the second winding portion 2e contacts the ridge portion 38 of the first intermediate core portion 31f. Therefore, the heat of the second winding portion 2e is also easily transferred to the first intermediate core portion 31f.

[0073] The first winding wire 21 and the second winding wire 22 can use known winding wires. The first winding wire 21 and the second winding wire 22 of the present embodiment are coated flat wires. The coated flat wire is easy to be arranged in the groove portion 36, so it is easy to make the first winding wire 21 and the groove portion 36 contact. Therefore, the heat of the first winding wire 21 is easily transferred to the first intermediate core portion 31f. The conductor wire of the coated flat wire is composed of a copper flat wire. The insulating coating layer of the coated flat wire is composed of enamel. The first winding portion 2i and the second winding portion 2e are formed by flat-winding the coated flat wire. Compared with the first winding portion 2i and the second winding portion 2e wound in an oblong manner, the flat-wound first winding portion 2i and the second winding portion 2e are easy to bend the coated flat wire, so they are easy to manufacture.

[0074] The first winding portion 2i is produced by winding the first winding wire 21 along the spiral groove 37 of the first intermediate core 31f. The second winding portion 2e is produced by winding the second winding wire 22 along the first intermediate core 31f and the outer periphery of the first winding portion 2i. The first winding wire 21 is wound from the first end portion of the first intermediate core 31f toward the second end portion. The second winding wire 22 is wound from the second end portion toward the first end portion. The first winding wire 21 and the second winding wire 22 are connected at the second end portion.

[0075] 《Other Implementation Methods》 Next, reactors according to Embodiments 2 to 6 that are different from Embodiment 1 will be described. The description of Embodiments 2 to 6 will focus on the differences from Embodiment 1. The description of the same structure as Embodiment 1 may be omitted.

[0076] Implementation Method 2 like Figure 7 As shown, as the reactor of the second embodiment, the first winding portion 2i and the second winding portion 2e may be configured by edgewise winding of a coated flat wire. When the length of the first winding portion 2i and the second winding portion 2e along the axial direction is constant, the edgewise wound first winding portion 2i and the second winding portion 2e can easily increase the number of turns compared with the flat wound first winding portion 2i and the second winding portion 2e. When the number of turns of the first winding portion 2i and the second winding portion 2e is constant, the edgewise wound first winding portion 2i and the second winding portion 2e can easily reduce the length along the axial direction compared with the flat wound first winding portion 2i and the second winding portion 2e. Therefore, the edgewise wound first winding portion 2i and the second winding portion 2e can be more compact than the flat wound first winding portion 2i and the second winding portion 2e. In the present embodiment, the width of each groove portion 36 is the same as the thickness of the first winding wire 21. The depth of each groove 36 is the same as the width of the first winding wire 21 . In addition, the depth of each groove 36 may be smaller or larger than the width of the first winding wire 21 .

[0077] Implementation Method 3 like Figure 8 As shown, as the reactor of the third embodiment, the outline shape of each groove 36 may be U-shaped, and the first winding wire 21 and the second winding wire 22 may be round wires. The width and depth of each groove 36 are the same as the diameter of the first winding wire 21.

[0078] Implementation Method 4 like Fig. 9 As shown, as the reactor of Embodiment 4, the contour shape of each groove 36 can be V-shaped, and the first winding wire 21 and the second winding wire 22 can be round wires. The opening width of each groove 36 can be greater than the diameter of the first winding wire 21, and the depth of each groove 36 can be greater than the diameter of the first winding wire 21.

[0079] Implementation Method 5 like Fig.10 , Fig.11 As shown, as the reactor of embodiment 5, the core 30 may also include a core body 30a and an insulating portion 30b provided along the outer peripheral surface of the core body 30a. The insulating portion 30b can easily improve the insulation between the core body 30a and the coil 2. The core body 30a is composed of the above-mentioned molded body or laminated body. The insulating portion 30b is composed of, for example, the same resin as the resin of the above-mentioned composite material molded body. The core body 30a and the insulating portion 30b of this embodiment are integrated. Unlike this embodiment, the core body 30a and the insulating portion 30b may also be independent of each other.

[0080] The core body 30a of the present embodiment has a quadrangular column shape, and the outer peripheral surface of the core body 30a is composed of four flat surfaces and four corners.

[0081] like Fig.10 As shown, at least one of the four planes of the core body portion 30a may also have a plurality of grooves 318 arranged in a direction along the axis of the core body portion 30a. Although omitted from the illustration, a plane facing a plane of the four planes of the core body portion 30a on which a plurality of grooves 318 are provided may also have a plurality of grooves 318. Furthermore, the remaining two planes of the core body portion 30a may also have a plurality of grooves 318. Furthermore, the four corners of the core body portion 30a may also have a plurality of grooves 318. The outer peripheral surface of the core body portion 30a may also have a spiral groove 319 coaxially arranged with the core body portion 30a.

[0082] like Fig.10 As shown, the insulating portion 30b has a first plane 35 provided with the above-mentioned multiple grooves 36. The first plane 35 of the insulating portion 30b is provided in a manner covering the planes provided with the multiple grooves 318 among the four planes of the core body portion 30a. Each groove 36 is along each groove 318. Although the insulating portion 30b is omitted in the figure, it can also be provided in a manner covering the four corners of the core body portion 30a. In the case where the multiple grooves 318 are also provided at the corners of the core body portion 30a, the portion of the insulating portion 30b covering the corners of the core body portion 30a also has multiple grooves 36. Each groove 36 at the corner of the insulating portion 30b is along each groove 318 at the corner of the core body portion 30a. The insulating portion 30b can also be provided in a manner covering the entire circumference of the outer peripheral surface of the core body portion 30a. The outer peripheral surface of the insulating portion 30b can also have the above-mentioned one spiral groove 37. The spiral groove 37 is provided coaxially with the insulating portion 30b. The spiral groove 37 of the insulating portion 30 b is arranged along the spiral groove 319 of the core body portion 30 a .

[0083] and Fig.10 The examples shown are different, such as Fig.11 As shown, the four planes and four corners of the core body 30a may not have the plurality of grooves 318. That is, the core body 30a may not have the spiral groove 319. The first plane 35 provided with the plurality of grooves 36 in the insulating portion 30b is provided in a manner covering the plane of the core body 30a. The outer peripheral surface of the insulating portion 30b may also have a spiral groove 37.

[0084] Implementation Method 6 Although omitted from the illustration, as the reactor of embodiment 6, the magnetic core may also have an intermediate core, a first side core, a second side core, a first end core, and a second end core. The intermediate core, the first side core, and the second side core are arranged in parallel along the direction of each other's axes. The intermediate core is arranged between the first side core and the second side core. The first side core is arranged face to face with the first end face of the intermediate core, the first end face of the first side core, and the first end face of the second side core. The second side core is arranged face to face with the second end face of the intermediate core, the second end face of the first side core, and the second end face of the second side core.

[0085] The magnetic core is composed of, for example, a combination of an E-shaped first chip and an I-shaped second chip, or a combination of a U-shaped first chip and a T-shaped second chip. The E-shaped first chip is a molded body or a laminated body in which the middle core, the first side core, the second side core and the first end core are integrated. The I-shaped second chip is composed of the second end core. The U-shaped first chip is a molded body or a laminated body in which the first side core, the second side core and the first end core are integrated. The T-shaped second chip is a molded body or a laminated body in which the middle core and the second end core are integrated.

[0086] In this embodiment, the core 30 described in Embodiment 1 may also constitute each first side core and second side core. The first coil 2f may be arranged on the periphery of the first side core, and the second coil 2s may be arranged on the periphery of the second side core. The first coil 2f and the second coil 2s may also be independent of each other.

[0087] Implementation Method 7 [Converter and power conversion device] Any one of the reactors 1 in Embodiments 1 to 6 can be used for applications that satisfy the following power-on conditions. The power-on conditions are as follows. The maximum DC current is, for example, greater than 100 A and less than 1000 A. The average voltage is, for example, greater than 100 V and less than 1000 V. The operating frequency is, for example, greater than 5 kHz and less than 100 kHz. Any one of the reactors 1 in Embodiments 1 to 6 can be representatively used as a component of a converter mounted on a vehicle 1200 such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, or as a component of a power conversion device having the converter.

[0088] like Fig.12As shown, vehicle 1200 includes a main battery 1210, a power conversion device 1100 connected to main battery 1210, and an electric motor 1220 driven by power supplied from main battery 1210 and used for traveling. Electric motor 1220 is typically a three-phase AC motor. Electric motor 1220 drives wheels 1250 during traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, vehicle 1200 includes an engine 1300 in addition to electric motor 1220. Fig.12 In FIG. 1 , a socket is shown as a charging location of vehicle 1200 , but a plug may be provided.

[0089] The power conversion device 1100 includes a converter 1110 and an inverter 1120. The converter 1110 is connected to a main battery 1210. The inverter 1120 is connected to the converter 1110. The inverter 1120 performs mutual conversion between direct current and alternating current. The converter 1110 shown in this example boosts the input voltage of the main battery 1210 of 200V or more and 300V or less to 400V or more and 700V or less when the vehicle 1200 is running, and supplies power to the inverter 1120. During regeneration, the converter 1110 steps down the input voltage output from the motor 1220 via the inverter 1120 to a DC voltage suitable for the main battery 1210, and charges the main battery 1210. The input voltage is a DC voltage. When the vehicle 1200 is running, the inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC, and supplies power to the motor 1220. Inverter 1120 converts the AC output from motor 1220 into DC during regeneration and outputs the DC to converter 1110 .

[0090] like Fig.13 As shown, the converter 1110 includes a plurality of switching elements 1111, a drive circuit 1112 for controlling the operation of the switching elements 1111, and a reactor 1115. The converter 1110 converts the input voltage by repeatedly switching on / off. The conversion of the input voltage here is to perform step-up and step-down. The switching element 1111 utilizes power devices such as field effect transistors and insulated gate bipolar transistors. The reactor 1115 has the following function: utilizing the coil property of hindering the change of the current to be passed through the circuit, when the current is to be increased or decreased due to the switching action, the change is smoothed. As the reactor 1115, any one of the reactors 1 in Embodiments 1 to 6 is provided. The power conversion device 1100 and the converter 1110 provided with the reactor 1 will not be enlarged, and it can be expected that the heat dissipation will be improved.

[0091] The vehicle 1200 includes a power supply device converter 1150 and an auxiliary power supply converter 1160 in addition to the converter 1110. The power supply device converter 1150 is connected to the main battery 1210. The auxiliary power supply converter 1160 is connected to the sub-battery 1230 and the main battery 1210, which are power sources for the auxiliary machines 1240. The auxiliary power supply converter 1160 converts the high voltage of the main battery 1210 into a low voltage. The converter 1110 typically performs DC-DC conversion, but the power supply device converter 1150 and the auxiliary power supply converter 1160 perform AC-DC conversion. The power supply device converter 1150 also includes a power supply device converter that performs DC-DC conversion. The reactors of the power supply device converter 1150 and the auxiliary power supply converter 1160 have the same structure as the reactor 1 in any one of the first to sixth embodiments, and a reactor whose size, shape, etc. are appropriately changed can be used. Furthermore, a converter that converts input power, a converter that only performs voltage step-up, or a converter that only performs voltage step-down may use any of the reactors 1 and the like in the first to sixth embodiments.

[0092] The present invention is not limited to these examples but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. Description of Reference Numerals

[0093] 1 Reactor 2 coils, 2f first coil, 2s second coil 2i first winding part, 2e second winding part 21 first winding wire, 22 second winding wire 3 cores, 30 cores 30a core body, 30b insulation part 31f first intermediate core, 31s second intermediate core 318 groove, 319 spiral groove 33f first end core, 33s second end core 35 first plane, 36 groove portion, 37 spiral groove, 38 ridge portion 1100 Power conversion device, 1110 converter 1111 switching element, 1112 driving circuit, 1115 reactor 1120 Inverter 1150 Converter for power supply device, 1160 Converter for auxiliary power supply 1200 vehicles 1210 main battery, 1220 electric motor, 1230 auxiliary battery 1240 auxiliary machinery, 1250 wheels 1300 Engine

Claims

1. A reactor, comprising: a magnetic core having a core portion configured in a prism shape; and, The coil has a first winding portion arranged on the outer periphery of the core portion and a second winding portion arranged on the outer periphery of the first winding portion, wherein: The first winding portion is composed of a first winding wire, and the first winding wire is wound in a spiral shape along the outer peripheral surface of the core. The second winding portion is composed of a second winding wire, and the second winding wire is wound along the outer peripheral surface of the first winding portion. The first winding wire and the second winding wire are continuous winding wires, The number of turns of the first winding portion is less than the number of turns of the second winding portion, The outer peripheral surface of the core includes a first plane having a plurality of grooves arranged in a direction along the axis of the core. A portion of the first winding wire in each turn of the first winding portion is arranged in each of the plurality of groove portions.

2. The reactor according to claim 1, wherein: The outer peripheral surface of the core has a spiral groove arranged coaxially with the core. Each of the plurality of groove portions constitutes a portion of the spiral groove, The first winding wire in all turns of the first winding portion is arranged in the spiral groove.

3. The reactor according to claim 1 or claim 2, wherein: The depth of each of the plurality of grooves is equal to the length of the first winding wire in a cross section along the depth direction.

4. The reactor according to claim 1 or claim 2, wherein: The depth of each of the plurality of grooves is smaller than the length of the first winding wire in a cross section along the depth direction.

5. The reactor according to claim 1 or claim 2, wherein: The depth of each of the plurality of grooves is greater than the length of the first winding wire in a cross section along the depth direction.

6. The reactor according to any one of claims 1 to 5, wherein: The first winding wire and the second winding wire are flat wires, Each of the plurality of grooves cut along the axis of the core has a rectangular cross-sectional shape.

7. The reactor according to claim 6, wherein: The first winding portion and the second winding portion are formed by flat-winding the flat wire.

8. The reactor according to claim 6, wherein: The first winding portion and the second winding portion are formed by flat-winding the flat wire.

9. The reactor according to any one of claims 1 to 8, wherein: The core is in the shape of a quadrangular column. The first winding portion and the second winding portion are in a quadrangular cylindrical shape.

10. The reactor according to any one of claims 1 to 9, wherein: The core portion includes a core main body portion mainly made of a magnetic material and an insulating portion provided along an outer peripheral surface of the core main body portion. The plurality of grooves are provided in the insulating portion.

11. A magnetic core having a core portion in the shape of a prism, The outer peripheral surface of the core portion includes a first plane having a plurality of grooves arranged in a direction along the axis of the core portion.

12. The magnetic core according to claim 11, wherein: The outer peripheral surface of the core has a spiral groove arranged coaxially with the core. Each of the plurality of groove portions constitutes a portion of the spiral groove. 13 . A converter comprising the reactor according to claim 1 .

14. A power conversion device comprising the converter according to claim 13.

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