Reactor, converter, and power conversion device
The reactor design addresses the challenge of connecting thin winding sections by aligning helical windings in a parallel configuration with a simple joint, enabling easy assembly and minimizing magnetic interference for a compact, efficient reactor.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- AUTONETWORKS TECH LTD
- Filing Date
- 2026-01-07
- Publication Date
- 2026-07-16
AI Technical Summary
Existing reactors are not designed to facilitate easy connection of winding ends from thin winding sections without additional connecting members, which complicates construction and may interfere with the magnetic path.
A reactor design with helically wound first and second winding portions aligned in a parallel configuration, allowing terminal sections to be connected simply at a joint without additional members, and covered by molded resin to maintain shape and reduce interference with the magnetic core.
Enables easy connection of winding ends, reduces the need for additional components, and allows for a compact, flat reactor construction with minimal interference with the magnetic path, facilitating efficient heat dissipation and improved handling.
Smart Images
Figure JP2026000277_16072026_PF_FP_ABST
Abstract
Description
Reactor, Converter, and Power Conversion Device
[0001] The present disclosure relates to a reactor, a converter, and a power conversion device. This application claims priority based on Japanese Patent Application No. 2025-003545 filed on January 9, 2025, and incorporates by reference all the descriptions set forth in the Japanese application.
[0002] Patent Document 1 discloses a reactor device in which two coils are arranged side by side, and one end of each coil is connected by welding. The connected ends of the coils protrude outward along the axis of the coil rather than from the end face of the coil.
[0003] Japanese Patent Application Laid-Open No. 2013-65754
[0004] The reactor of this disclosure comprises a coil and a magnetic core. The coil comprises a first winding portion, a second winding portion, a first terminal portion, a second terminal portion, and a joint portion. The first winding portion is formed of a first winding wound in a helical manner. The second winding portion is formed of a second winding wound in a helical manner. The first winding portion and the second winding portion are arranged side by side such that the axis of the first winding portion and the axis of the second winding portion are parallel. Each of the first winding portion and the second winding portion has a rectangular envelope shape that is elongated in a second direction along the direction in which the first winding portion and the second winding portion are aligned, when viewed from a first direction along the axis of the first winding portion and the axis of the second winding portion. The first terminal portion comprises a first transverse portion and a first longitudinal portion formed of the first winding drawn out from the first winding portion. The first transverse portion extends along the second direction from the first winding portion toward the second winding portion. The first vertical portion extends from the end of the first horizontal portion along the first direction. The second terminal portion comprises a second horizontal portion and a second vertical portion formed by the second winding drawn out from the second winding portion. The second horizontal portion extends from the second winding portion along the second direction. The second vertical portion extends from the end of the second horizontal portion along the first direction. The joint is the point where the tip of the first vertical portion and the tip of the second vertical portion are connected. The magnetic core comprises a first inner core portion, a second inner core portion, a first outer core portion, and a second outer core portion. The first inner core portion is located inside the first winding portion. The second inner core portion is located inside the second winding portion. The first outer core portion is located facing the first end faces of the first winding portion and the second winding portion so as to be connected to the first ends of the first inner core portion and the second inner core portion, respectively. The second outer core portion is positioned facing the second end faces of the first and second winding portions so as to be connected to the second ends of the first and second inner core portions, respectively. The first and second vertical portions are located outward along the second direction from the first virtual plane which is an extension of the outer surface of the second inner core portion.
[0005] Figure 1 is a schematic perspective view showing a reactor of the embodiment. Figure 2 is a schematic top view showing a reactor of the embodiment. Figure 3 is a schematic perspective view showing a coil provided in the reactor of the embodiment. Figure 4 is a schematic end view of the coil provided in the reactor of the embodiment viewed from a first direction. Figure 5 is a schematic top view showing a coil provided in the reactor of the embodiment. Figure 6 is a schematic configuration diagram showing the power supply system of a hybrid vehicle. Figure 7 is a circuit diagram showing an example of a power conversion device equipped with a converter.
[0006] There is a demand for thin reactors. Thin reactors are expected to allow for miniaturization, weight reduction, and greater flexibility in reactor placement.
[0007] Each of the two coils has a winding section in which the winding is wound in a helical shape. In the case of a thin reactor, each winding section is also thin. In a thin reactor having two winding sections, it is desirable to connect the ends of the windings drawn from the first ends of each winding section with a simple configuration.
[0008] One of the purposes of this disclosure is to provide a reactor in which the terminals of windings drawn from the first ends of each of two thin winding sections are connected in a simple configuration. Another purpose of this disclosure is to provide a converter equipped with the above reactor. Another purpose of this disclosure is to provide a power conversion device equipped with the above converter.
[0009] In the reactor of this disclosure, the ends of the windings drawn from the first ends of each of the two thin winding sections can be connected to each other in a simple configuration.
[0010] First, the embodiments of this disclosure will be listed and described.
[0011] (1) A reactor according to an embodiment of the present disclosure comprises a coil and a magnetic core. The coil comprises a first winding portion, a second winding portion, a first terminal portion, a second terminal portion, and a joint portion. The first winding portion is formed of a first winding wound in a helical manner. The second winding portion is formed of a second winding wound in a helical manner. The first winding portion and the second winding portion are arranged side by side such that the axis of the first winding portion and the axis of the second winding portion are parallel. Each of the first winding portion and the second winding portion has a rectangular envelope shape that is elongated in a second direction along the direction in which the first winding portion and the second winding portion are aligned, when viewed from a first direction along the axis of the first winding portion and the axis of the second winding portion. The first terminal portion comprises a first horizontal portion and a first vertical portion formed of the first winding drawn out from the first winding portion. The first horizontal portion extends along the second direction from the first winding portion toward the second winding portion. The first vertical portion extends from the end of the first horizontal portion along the first direction. The second terminal portion comprises a second horizontal portion and a second vertical portion formed by the second winding drawn out from the second winding portion. The second horizontal portion extends from the second winding portion along the second direction. The second vertical portion extends from the end of the second horizontal portion along the first direction. The joint is the point where the tip of the first vertical portion and the tip of the second vertical portion are connected. The magnetic core comprises a first inner core portion, a second inner core portion, a first outer core portion, and a second outer core portion. The first inner core portion is located inside the first winding portion. The second inner core portion is located inside the second winding portion. The first outer core portion is located facing the first end faces of the first winding portion and the second winding portion so as to be connected to the first ends of the first inner core portion and the second inner core portion, respectively. The second outer core portion is positioned facing the second end faces of the first and second winding portions so as to be connected to the second ends of the first and second inner core portions, respectively. The first and second vertical portions are located outward along the second direction from the first virtual plane which is an extension of the outer surface of the second inner core portion.
[0012] The reactor is thin because the first and second winding sections of the coil are aligned in a second direction, and each of the first and second winding sections is long in the second direction. The first terminal section drawn out from the first winding section and the second terminal section drawn out from the second winding section are connected. In the configuration in which the first and second terminal sections are connected, the coil can be formed more easily than when the first and second winding sections are formed from a single winding. In the configuration in which the first and second terminal sections are connected, additional connecting members such as busbars are not required to connect the first and second terminal sections. Since no connecting members are required, there is only one connection point between the first and second terminal sections. In the configuration in which the first and second terminal sections are connected, the first and second terminal sections can be connected either before or after combining the coil and the magnetic core. As described later, when at least a part of the first and second winding sections are covered with molded resin, the first and second terminal sections can be connected either before or after covering the coil with the molded resin. As described above, in a configuration in which the first terminal and the second terminal are connected, the first terminal and the second terminal, which are drawn out from the first ends of each of the two thin winding sections, can be connected in a simple manner.
[0013] Although the first and second terminal portions of the coil protrude in the first direction relative to the end faces of the first and second winding portions, these protruding first and second longitudinal portions are located at the ends of the reactor in the second direction. The ends of the reactor in the second direction are outward along the second direction from the first virtual plane, which is an extension of the outer surface of the second inner core portion. Because the first and second longitudinal portions are located at the ends of the reactor in the second direction, the first and second terminal portions do not substantially interfere with the magnetic path of the magnetic core. Therefore, the height of the first outer core portion, excluding the locations of the first and second longitudinal portions, can be made the same as the heights of the first and second winding portions, respectively. The heights of the first outer core portion, the first winding portion, and the second winding portion are the lengths along the third direction in each portion. The third direction is perpendicular to both the first and second directions.
[0014] The first and second terminal sections are located within a plane encompassing the first and second directions, and are unlikely to protrude in the third direction from the first and second winding sections. Therefore, multiple reactors can be arranged in a line in the third direction.
[0015] (2) In the reactor described in (1) above, the first outer core portion may include an end region located outward along the second direction from the first virtual plane. The end region may include a notch that forms the arrangement space for the first vertical portion and the second vertical portion.
[0016] The end region is an area that does not affect the magnetic path of the magnetic core. Therefore, even if a notch is formed in the first outer core portion, the magnetic path area is unlikely to decrease. When a notch is formed in the end region, the first and second vertical portions are unlikely to protrude from the first outer core portion in a third direction.
[0017] (3) The reactor described in (1) or (2) above may include a molded resin portion that covers at least a part of the first winding portion and the second winding portion and maintains the respective shapes of the first winding portion and the second winding portion.
[0018] The shapes of the first and second winding sections are maintained by the molded resin section, making it easier to construct a flat, thin reactor.
[0019] (4) In the reactor described in (3) above, the molded resin portion may include a side resin portion that covers the outer surface of the second winding portion. The first vertical portion and the second vertical portion may be located between a second virtual surface, which is an extension of the outer surface of the side resin portion, and the first virtual surface.
[0020] When the molded resin part includes a side resin part, for example, the outer surface of the side resin part forms part of the reactor's outer shape. In this case, if the first vertical part and the second vertical part are located between the second virtual surface and the first virtual surface, the first vertical part and the second vertical part are less likely to protrude from the reactor's outer shape in the second direction.
[0021] (5) In the reactor described in any of (1) to (4) above, the number of turns of the second winding portion may be substantially one turn less than the number of turns of the first winding portion.
[0022] Because the number of turns in the second winding section is substantially one turn less than that of the first winding section, the area of the first lateral section that overlaps with the first end face of the second winding section is less likely to protrude in the first direction than the first end face of the first winding section. In other words, the first lateral section can be made straight. If the number of turns in the first winding section and the second winding section are the same, it is necessary to create a step in the first lateral section to avoid interference with the first end face of the second winding section. If the number of turns in the second winding section is substantially one turn less than that of the first winding section, it is not necessary to create the above step, and the number of bending processes required for the second winding can be reduced.
[0023] (6) In the reactor described in any of (1) to (5) above, the ratio of the long side to the short side in the envelope shape may be 2.5 or more.
[0024] The ratio of the long side to the short side forming the shape of the first and second winding sections is 2.5 or greater, making it easier to construct a flat, thin reactor.
[0025] (7) A converter according to an embodiment of the present disclosure comprises a reactor as described in any of (1) to (6) above.
[0026] Converters equipped with the above-mentioned reactor are thin.
[0027] (8) A power conversion device according to the embodiment of the present disclosure comprises the converter described in (7) above.
[0028] The power converter equipped with the above converter is thin.
[0029] [Details of Embodiments of the Disclosure] Specific examples of embodiments of the disclosure will be described below with reference to the drawings. Identical reference numerals in the drawings indicate identical parts. In each drawing, some parts of the configuration may be exaggerated or simplified for illustrative purposes. The dimensional ratios of parts in the drawings may also differ from those of the actual components. The present invention is not limited to these examples, but is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included. It should be understood that at least one configuration or feature described in each embodiment and example can be combined with other embodiments and examples, or modified in various ways.
[0030] <Reactor> The reactor 1 of the embodiment will be described with reference to Figures 1 to 5.
[0031] ≪Overview≫ As shown in Figures 1 and 2, the reactor 1 comprises a coil 2 and a magnetic core 6. As shown in Figure 3, the coil 2 comprises a first winding portion 31, a second winding portion 32, a first terminal portion 41, a second terminal portion 42, and a joint portion 45. The first winding portion 31 is formed of a first winding 21 wound in a helical manner. The second winding portion 32 is formed of a second winding 22 wound in a helical manner. The first terminal portion 41 comprises a first horizontal portion 411 and a first vertical portion 412 formed of the first winding 21 drawn out from the first winding portion 31. The second terminal portion 42 comprises a second horizontal portion 421 and a second vertical portion 422 formed of the second winding 22 drawn out from the second winding portion 32. The first vertical portion 412 and the second vertical portion 422 extend along a first direction D1. The joint 45 is the point where the tip 415 of the first vertical portion 412 and the tip 425 of the second vertical portion 422 are connected. One of the features of the reactor 1 of this embodiment is that, as shown in Figure 2, the first vertical portion 412 and the second vertical portion 422 are located outward along the second direction D2 from the first virtual surface 7S which is an extension of the outer surface 75 of the second inner core portion 72 of the magnetic core 6.
[0032] In this specification, the first direction D1, the second direction D2, and the third direction D3 may be used for explanation. The first direction D1 is the direction along the axis of the first winding section 31 and the axis of the second winding section 32. The second direction D2 is the direction in which the first winding section 31 and the second winding section 32 are aligned. The third direction D3 is the direction perpendicular to both the first direction D1 and the second direction D2. The first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other. In each figure, the first direction D1, the second direction D2, and the third direction D3 are each indicated by a single arrow. In this specification, the opposite directions of the first direction D1, the second direction D2, and the third direction D3 may also be referred to as the first direction D1, the second direction D2, and the third direction D3, respectively.
[0033] <Coil> As shown in Figure 3, coil 2 comprises a first coil formed by a first winding 21 and a second coil formed by a second winding 22. Coil 2 is formed by connecting the first coil and the second coil in series at a joint 45.
[0034] [First coil] The first coil comprises a first winding portion 31, a first terminal portion 41, and a third terminal portion 43. The first winding portion 31, the first terminal portion 41, and the third terminal portion 43 are formed by a single continuous first winding wire 21.
[0035] The first winding section 31 is formed by a first winding 21 wound in a helical shape. The first winding 21 can be any known winding. In this example, the first winding 21 is a coated flat wire made of a conductor wire having an insulating coating. The conductor wire is, for example, a copper flat wire. The insulating coating is, for example, enamel. In this example, the first winding section 31 is formed by edgewise winding of the coated flat wire.
[0036] The first winding section 31 has a flattened cylindrical shape, as shown in Figures 3 and 4. Cylindrical shapes include racetrack-shaped cylindrical shapes, elliptical cylindrical shapes, and rectangular cylindrical shapes. The racetrack shape is formed by a first straight section, a second straight section, a first circular arc section, and a second circular arc section. The first straight section and the second straight section are parallel to each other and of the same length. The first circular arc section connects the first end of the first straight section and the first end of the second straight section. The second circular arc section connects the second end of the first straight section and the second end of the second straight section. Rectangular cylindrical shapes include square cylindrical shapes, etc. Rectangular cylindrical shapes also include rectangular cylindrical shapes with rounded corners. In this example, the first winding section 31 has a racetrack-shaped cylindrical shape.
[0037] As shown in Figure 4, the first winding portion 31 has a rectangular envelope shape 5 that is elongated in the second direction D2 when viewed from the first direction D1. In Figure 4, for clarity, the envelope shape 5 is shown as a dashed line slightly outside the outer shape of the first winding portion 31. The envelope shape 5 is the smallest rectangular shape that surrounds the first winding portion 31 when viewed from the first direction D1. The sides of the envelope shape 5 along the second direction D2 are the long sides 51, and the sides along the third direction D3 are the short sides 52. The ratio of the long sides 51 to the short sides 52 in the envelope shape 5 is, for example, 2.5 or more. The above ratio is a ratio in which the dimension of the long side 51 is the numerator and the dimension of the short side 52 is the denominator. The larger the value of the above ratio, the flatter and thinner the reactor 1 can be. The above ratio may be 3.0 or more, or 4.0 or more. The upper limit of the above ratio can be set appropriately according to the upper limit width of the reactor 1 that is required. The above ratio is, for example, 6.0 or less.
[0038] As shown in Figure 3, the first terminal portion 41 is formed by the first winding 21 drawn out from the first end of the first winding portion 31. The first terminal portion 41 comprises a first horizontal portion 411 and a first vertical portion 412. The first horizontal portion 411 extends along the second direction D2 from the first winding portion 31 toward the second winding portion 32. The first horizontal portion 411 extends outward along the second direction D2 beyond the first virtual surface 7S (Figure 2). The first virtual surface 7S is a surface that extends the outer surface 75 of the second inner core portion 72, which will be described later. Outward along the second direction D2 is the direction close to the end of the reactor 1 along the second direction D2. The first vertical portion 412 extends along the first direction D1 from the end of the first horizontal portion 411. The first horizontal portion 411 and the first vertical portion 412 are formed by bending the first winding 21 in an L-shape. This L-shaped bend is formed by flatwise bending the first winding 21.
[0039] At the tip 415 of the first vertical section 412, the insulating coating of the first winding 21 is stripped, exposing the conductor wire. This exposed conductor wire is connected to the conductor wire of the second winding 22 at the joint 45.
[0040] The third terminal portion 43 is formed by the first winding 21 drawn out from the second end of the first winding portion 31. In this example, the third terminal portion 43 extends from the second end of the first winding portion 31 along the first direction D1. At the tip of the third terminal portion 43, the insulating coating of the first winding 21 is stripped, exposing the conductor wire. A terminal fitting (not shown) is attached to this exposed conductor wire. An external device (not shown) is connected to the terminal fitting. The external device is, for example, a power supply.
[0041] [Second coil] The second coil comprises a second winding section 32, a second terminal section 42, and a fourth terminal section 44. The second winding section 32, the second terminal section 42, and the fourth terminal section 44 are formed by a single continuous second winding wire 22.
[0042] The second winding portion 32 is formed by a second winding wire 22 wound in a spiral shape. The second winding wire 22 has the same or a similar configuration to the first winding wire 21. The second winding portion 32 in this example is formed by edgewise winding a coated flat wire. The second winding portion 32 in this example has the same race track-shaped cylindrical shape as the first winding portion 31. The second winding portion 32 has a rectangular envelope shape 5 (FIG. 4) that is long in the second direction D2 when viewed from the first direction D1, as described for the first winding portion 31. In this example, the ratio of the long side 51 to the short side 52 in the envelope shape 5 of the second winding portion 32 is the same as the ratio of the long side 51 to the short side 52 in the envelope shape 5 of the first winding portion 31.
[0043] The first winding portion 31 and the second winding portion 32 are arranged side by side such that the axis of the first winding portion 31 and the axis of the second winding portion 32 are parallel. That is, the second winding portion 32 is arranged adjacent to the first winding portion 31 along the second direction D2. A slight gap is provided between the first winding portion 31 and the second winding portion 32.
[0044] As shown in FIG. 5, the number of turns of the second winding portion 32 may be substantially one turn less than the number of turns of the first winding portion 31. Substantially one turn less means that the first horizontal portion 411 of the first terminal portion 41 can be drawn out along the first end face of the second winding portion 32 from the first winding portion 31. Since the number of turns of the second winding portion 32 is substantially one turn less than the number of turns of the first winding portion 31, the region of the first horizontal portion 411 that overlaps the first end face of the second winding portion 32 is less likely to protrude in the first direction D1 than the first end face of the first winding portion 31. In other words, the first horizontal portion 411 can be made straight. When the number of turns of the first winding portion 31 and the number of turns of the second winding portion 32 are the same, it is necessary to provide a step in the middle of the first horizontal portion 411 so as not to interfere with the first end face of the second winding portion 32. If the number of turns of the second winding portion 32 is substantially one turn less than the number of turns of the first winding portion 31, there is no need to provide the above step, and the number of processing steps for bending the second winding wire 22 can be reduced.
[0045] In this example, the upper surface of the first winding portion 31 and the upper surface of the second winding portion 32 are flush. In this example, the lower surface of the first winding portion 31 and the lower surface of the second winding portion 32 are flush. The upper surface and the lower surface of the first winding portion 31 are surfaces facing each other in the third direction D3. The upper surface and the lower surface of the second winding portion 32 are surfaces facing each other in the third direction D3. Both the upper surface of the first winding portion 31 and the upper surface of the second winding portion 32 have a flat surface. Both the lower surface of the first winding portion 31 and the lower surface of the second winding portion 32 have a flat surface. By bringing a cooler into contact with at least a part of the flat surfaces of the first winding portion 31 and the second winding portion 32, the heat of the coil 2 can be efficiently released.
[0046] As shown in FIG. 3, the second terminal portion 42 is formed by a second winding wire 22 drawn from the first end portion of the second winding portion 32. The second terminal portion 42 includes a second horizontal portion 421 and a second vertical portion 422. The second horizontal portion 421 extends from the second winding portion 32 along the second direction D2. The second horizontal portion 421 extends outward along the second direction D2 beyond the first virtual plane 7S (FIG. 2). The second horizontal portion 421 is arranged side by side so as to be close to or in contact with the first horizontal portion 411. The second vertical portion 422 extends from the end of the second horizontal portion 421 along the first direction D1. The second vertical portion 422 is arranged side by side so as to be close to or in contact with the first vertical portion 412. The second horizontal portion 421 and the second vertical portion 422 are formed by bending the second winding wire 22 in an L shape. This L-shaped bend is formed by bending the second winding wire 22 flatwise.
[0047] At the tip portion 425 of the second vertical portion 422, the insulating coating of the second winding wire 22 is peeled off and the conductor wire is exposed. This exposed conductor wire is connected to the conductor wire of the first winding wire 21 at the joint portion 45.
[0048] The fourth terminal portion 44 is formed by the second winding 22 drawn out from the second end of the second winding portion 32. In this example, the fourth terminal portion 44 extends from the second end of the second winding portion 32 along the first direction D1. At the tip of the fourth terminal portion 44, the insulating coating of the second winding 22 is stripped, exposing the conductor wire. A terminal fitting (not shown) is attached to this exposed conductor wire. An external device (not shown) is connected to the terminal fitting. The external device is, for example, a power supply.
[0049] [Joint] As shown in Figure 2, the first vertical portion 412 and the second vertical portion 422 are located outward along the second direction D2 from the first virtual surface 7S. In this example, the first vertical portion 412 and the second vertical portion 422 are located between the first virtual surface 7S and the second virtual surface 9S. The second virtual surface 9S is a surface that extends the outer surface 945 of the side resin portion 94, which is part of the molded resin portion 9 described later. Although the first vertical portion 412 and the second vertical portion 422 protrude in the first direction D1 from the first end faces of the first winding portion 31 and the second winding portion 32, the protruding first vertical portion 412 and the second vertical portion 422 are located outward along the second direction D2 from the first virtual surface 7S. Therefore, the first terminal portion 41 and the second terminal portion 42 do not substantially interfere with the magnetic path of the magnetic core 6.
[0050] The tip 415 of the first vertical section 412 and the tip 425 of the second vertical section 422 are connected at a joint 45. The method of connecting the tip 415 of the first vertical section 412 and the tip 425 of the second vertical section 422 is, for example, welding, crimping, or pressure welding. For welding, for example, laser beam welding, electron beam welding, ultrasonic welding, or resistance welding. In this example, the joint 45 is located outward in the first direction D1 from the outer end surface 815 of the first outer core section 81. In the configuration in which the first terminal section 41 and the second terminal section 42 are connected, the coil 2 can be formed more easily than when the first winding section 31 and the second winding section 32 are formed from a single winding. In the configuration in which the first terminal section 41 and the second terminal section 42 are connected, additional connecting members such as busbars for connecting the first terminal section 41 and the second terminal section 42 are not required. Since no connecting member is required, the connection point between the first terminal portion 41 and the second terminal portion 42 is a single joint portion 45.
[0051] <Molded Resin Part> At least a portion of the first winding portion 31 and the second winding portion 32 may be covered by the molded resin part 9, as shown in Figures 1 and 2. The molded resin part 9 maintains the shape of the first winding portion 31 and the second winding portion 32 by covering at least a portion of them. The shape of the first winding portion 31 and the second winding portion 32 is maintained by the molded resin part 9, making it easier to construct a flat, thin reactor 1. The shape of the first winding portion 31 and the second winding portion 32 is maintained by the molded resin part 9, making it easier to handle the coil 2 as a molded coil comprising the coil 2 and the molded resin part 9.
[0052] The molded resin portion 9 comprises a first end face resin portion 91, a second end face resin portion 92, side resin portions 93, 94, and an intermediate portion 95. The first end face resin portion 91 is positioned to cover the first end faces of the first winding portion 31 and the second winding portion 32. The first end face resin portion 91 is positioned between the first winding portion 31 and the second winding portion 32 and the first outer core portion 81. The first end face resin portion 91 has two through holes formed therein, into which the first ends of the first inner core portion 71 and the second inner core portion 72 are positioned. The second end face resin portion 92 is positioned to cover the second end faces of the first winding portion 31 and the second winding portion 32. The second end face resin portion 92 is positioned between the first winding portion 31 and the second winding portion 32 and the second outer core portion 82. The second end face resin portion 92 has two through holes formed therein, into which the second ends of the first inner core portion 71 and the second inner core portion 72 are positioned. The side resin portion 93 is positioned to cover the outer surface of the first winding portion 31. The side resin portion 94 is positioned to cover the outer surface of the second winding portion 32. The side resin portions 93 and 94 form a part of the outer shape of the reactor 1. The intermediate portion 95 is positioned between the first winding portion 31 and the second winding portion 32. In this example, the upper and lower surfaces of the first winding portion 31 and the upper and lower surfaces of the second winding portion 32 are not covered by the molded resin portion 9. If the upper and lower surfaces of the first winding portion 31 and the upper and lower surfaces of the second winding portion 32 are exposed from the molded resin portion 9, the heat dissipation of the coil 2 is easily improved. The upper and lower surfaces of the first winding portion 31 and the upper and lower surfaces of the second winding portion 32 may also be covered by the molded resin portion 9. The inner circumferential surfaces of the first winding portion 31 and the inner circumferential surfaces of the second winding portion 32 may also be covered by the molded resin portion 9. When the first winding portion 31 and the second winding portion 32 are covered by the molded resin portion 9, the electrical insulation of the coil 2 is easily improved.
[0053] ≪Magnetic Core≫ As shown in Figures 1 and 2, the magnetic core 6 comprises a first inner core portion 71, a second inner core portion 72, a first outer core portion 81, and a second outer core portion 82. The first inner core portion 71 is located inside the first winding portion 31. The second inner core portion 72 is located inside the second winding portion 32. The first outer core portion 81 is located facing the first end faces of the first winding portion 31 and the second winding portion 32 so as to be connected to the first ends of the first inner core portion 71 and the second inner core portion 72, respectively. The second outer core portion 82 is located facing the second end faces of the first winding portion 31 and the second winding portion 32 so as to be connected to the second ends of the first inner core portion 71 and the second inner core portion 72, respectively. The first inner core portion 71, the second inner core portion 72, the first outer core portion 81, and the second outer core portion 82 are connected in a series so that when the coil 2 is energized, an annular closed magnetic path is formed in the magnetic core 6.
[0054] As shown in Figure 2, the first inner core portion 71 extends along the axis of the first winding portion 31. The first and second ends of the first inner core portion 71 may protrude from the ends of the first winding portion 31. These protruding portions are also part of the first inner core portion 71. In other words, the length of the first inner core portion 71 along the first direction D1 may be longer than the length of the first winding portion 31 along the first direction D1. The shape of the first inner core portion 71 generally corresponds to the inner circumferential contour shape of the first winding portion 31. The second inner core portion 72 has the same configuration as the first inner core portion 71.
[0055] The first outer core portion 81 is a columnar body extending along the second direction D2, as shown in Figures 1 and 2. The shape of the first outer core portion 81 is a rectangular prism. The first outer core portion 81 comprises an upper surface 811, a lower surface 812, side surfaces 813 and 814, an outer end surface 815, and an inner end surface. The upper surface 811 and the lower surface 812 are surfaces facing opposite directions in the third direction D3. The side surfaces 813 and 814 are surfaces facing opposite directions in the second direction D2. The outer end surface 815 and the inner end surface are surfaces facing opposite directions in the first direction D1. The outer end surface 815 is the surface facing the first winding portion 31 and the second winding portion 32 in the opposite direction. The inner end surface is the surface facing the first winding portion 31 and the second winding portion 32. In this example, the top surface 811, the bottom surface 812, the side surfaces 813 and 814, the outer end surface 815, and the inner end surface are all flat.
[0056] In this example, the upper surface 811 is flush with the upper surface of the first winding portion 31 and the upper surface of the second winding portion 32. The upper surface 811 in this example is also flush with the upper surface of the first end face resin portion 91 of the molded resin portion 9. The lower surface 812 in this example is flush with the lower surface of the first winding portion 31 and the lower surface of the second winding portion 32. The lower surface 812 in this example is also flush with the lower surface of the first end face resin portion 91 of the molded resin portion 9. In other words, in this example, the height of the first outer core portion 81 is the same as the height of the first winding portion 31 and the second winding portion 32, respectively. The height of the first outer core portion 81, the height of the first winding portion 31, and the height of the second winding portion 32 are the lengths along the third direction D3 in each of them.
[0057] In this example, side surface 813 is flush with the outer surface 935 of the side resin portion 93 of the molded resin portion 9. In this example, side surface 814 is flush with the outer surface 945 of the side resin portion 94 of the molded resin portion 9.
[0058] In this example, the first winding portion 31, the second winding portion 32, the side resin portions 93 and 94, the first outer core portion 81, and the second outer core portion 82 form a long, flat, rectangular columnar body in the second direction D2.
[0059] The first outer core portion 81 in this example includes an end region 818 located outward along the second direction D2 from the first virtual surface 7S shown in Figure 2. The end region 818 includes a notch 819 opening to the side surface 814, the outer end surface 815, and the inner end surface. The notch 819 creates a space for the arrangement of the first vertical portion 412 and the second vertical portion 422 in the first outer core portion 81. The end region 818 is a region that does not affect the magnetic path of the magnetic core 6. Therefore, even if the notch 819 is formed in the first outer core portion 81, the magnetic path area is unlikely to decrease. When the notch 819 is formed in the end region 818, the first vertical portion 412 and the second vertical portion 422 are unlikely to protrude from the upper surface 811 of the first outer core portion 81.
[0060] The end region 818 is optional. If the end region 818 is absent, a step is formed between the outer surface 945 of the side resin portion 94, which is part of the molded resin portion 9, and the side surface 814 of the first outer core portion 81.
[0061] The second outer core portion 82 is also a columnar body extending along the second direction D2. The shape of the second outer core portion 82 is a rectangular prism. In this example, as described for the first outer core portion 81, the height of the second outer core portion 82 is the same as the heights of the first winding portion 31 and the second winding portion 32, respectively. If the height of the second outer core portion 82 is the same as the heights of the first winding portion 31 and the second winding portion 32, the magnetic path area of the magnetic core 6 is less likely to decrease. Two notches (not shown) are formed on the lower surface of the second outer core portion 82. These two notches create spaces for the arrangement of the third terminal portion 43 and the fourth terminal portion 44 in the second outer core portion 82.
[0062] The magnetic core 6 is formed from a molded composite material or a compacted powder. The magnetic core 6 may be formed solely from a molded composite material, solely from a compacted powder, or from a combination of a molded composite material and a compacted powder.
[0063] A molded article of a composite material is a molded article in which soft magnetic powder is dispersed in a resin. A molded article of a composite material is obtained by filling a mold with a fluid material in which soft magnetic powder is dispersed in an unsolidified resin, and then solidifying the resin. The content of soft magnetic powder in the resin of a molded article of a composite material can be easily adjusted. Therefore, the magnetic properties of a molded article of a composite material can be easily adjusted. In addition, a molded article of a composite material can be formed into a complex shape more easily than a compacted powder molded article. The content ratio of soft magnetic powder in a molded article of a composite material is, for example, 20% to 80% by volume. The content ratio of resin in a molded article of a composite material is, for example, 20% to 80% by volume. These content ratios are values when the molded article of a composite material is 100% by volume.
[0064] A powder compact is a molded body made by compressing soft magnetic powder. A powder compact is obtained by filling a cavity with soft magnetic powder and applying pressure to the powder within the cavity using a punch. Compared to molded bodies made of composite materials, powder compacts allow for a higher proportion of soft magnetic powder in the core. Therefore, powder compacts are easier to enhance in terms of magnetic properties. These magnetic properties include relative permeability and saturation magnetic flux density. Furthermore, because powder compacts contain a larger amount of soft magnetic powder compared to molded bodies made of composite materials, they exhibit superior heat dissipation. The content of magnetic powder in a powder compact is, for example, 85% to 99% by volume. This content is the value when the powder compact is 100% by volume.
[0065] The particles constituting the soft magnetic powder include particles of soft magnetic metal, coated particles, or particles of soft magnetic nonmetals. The coated particles may consist of soft magnetic metal particles and an insulating coating provided on the outer circumference 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 an Fe-Si alloy or an Fe-Ni alloy. An example of an insulating coating is a phosphate. An example of a soft magnetic nonmetal is ferrite.
[0066] Examples of resins used in molded composite materials include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include epoxy resins, phenolic resins, silicone resins, and urethane resins. Examples of thermoplastic resins include polyphenylene sulfide resins, polyamide resins, liquid crystal polymers, polyimide resins, and fluororesins. Examples of polyamide resins include nylon 6, nylon 66, and nylon 9T.
[0067] Molded composite materials may contain fillers. Examples of fillers include alumina or silica. Fillers contribute to improved heat dissipation and electrical insulation.
[0068] The content ratio of soft magnetic powder in a composite material molded body and the content ratio of soft magnetic powder in a compacted molded body are considered equivalent to the area ratio of soft magnetic powder in the cross-section of the molded body. The content ratio of soft magnetic powder in the molded body is determined as follows: Observe the cross-section of the molded body with an SEM (scanning electron microscope) and acquire an observation image. The cross-section of the molded body can be any cross-section. The magnification of the SEM should be between 200x and 500x. Acquire at least 10 observation images. The total area of all observation images should be 0.1 cm². ２ The above procedure is followed. One observation image may be obtained for each cross-section, or multiple observation images may be obtained for each cross-section. Each obtained observation image is processed to extract the contours of the particles. For example, the image processing may be binarization. The area ratio of soft magnetic particles is calculated for each observation image, and the average value of these area ratios is determined. This average value is considered to be the content ratio of soft magnetic powder.
[0069] ≪Method for Manufacturing a Reactor≫ A reactor 1, in which the magnetic core 6 is formed from a molded composite material, can be manufactured as follows, for example. First, a molded coil comprising a coil 2 and a molded resin part 9 is placed in a predetermined position in a mold. A fluid composite material is filled into the mold in which the molded coil is placed and solidified.
[0070] A reactor 1 in which the magnetic core 6 is formed from a compacted powder can be manufactured, for example, as follows: First, the first inner core portion 71, the second inner core portion 72, the first outer core portion 81, and the second outer core portion 82 are molded individually. The core portions 71, 72, 81, and 82 are then combined with a molded coil comprising a coil 2 and a molded resin portion 9.
[0071] The reactor 1, in which the magnetic core 6 is formed by a combination of a molded composite material and a compacted powder molded body, can be manufactured, for example, as follows: First, the core portion made of the compacted powder molded body is molded. The core portion, consisting of a molded coil comprising a coil 2 and a molded resin portion 9 and a compacted powder molded body, is placed in a predetermined position in the mold. A fluid composite material is filled into the mold in which the core portion made of the molded coil and compacted powder molded body is placed and solidified.
[0072] <Converter / Power Conversion Device> The reactor 1 described above can be used for applications that meet the following energizing conditions. For example, the energizing conditions are that the maximum DC current is approximately 100A to 1000A, the average voltage is approximately 100V to 1000V, and the operating frequency is approximately 5kHz to 100kHz. The reactor 1 described above is typically used as a component of a converter installed in vehicles such as electric vehicles and hybrid vehicles, or as a component of a power conversion device equipped with this converter.
[0073] As shown in Figure 6, a vehicle 1200 such as a hybrid vehicle or an electric vehicle includes a main battery 1210, a power converter 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 driving. The motor 1220 is typically a three-phase AC motor, which drives the wheels 1250 during driving and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 is equipped with an engine 1300 in addition to the motor 1220. In Figure 6, the charging point of the vehicle 1200 is an inlet, but it may also be equipped with a plug.
[0074] The power conversion device 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110 that performs mutual conversion between DC and AC. In this example, the converter 1110 boosts the input voltage of the main battery 1210, which is approximately 200V to 300V, to approximately 400V to 700V 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, thereby charging the main battery 1210. The input voltage is a DC voltage. When the vehicle 1200 is running, the inverter 1120 converts the DC voltage boosted by the converter 1110 into a predetermined AC voltage and supplies power to the motor 1220. During regeneration, it converts the AC output from the motor 1220 into DC voltage and outputs it to the converter 1110.
[0075] As shown in Figure 7, the converter 1110 comprises a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115, and converts the input voltage by repeatedly switching ON / OFF. In this case, the input voltage conversion is step-up or step-down. Power devices such as field-effect transistors and insulated-gate bipolar transistors are used as switching elements 1111. The reactor 1115 utilizes the coil property that tries to oppose changes in the current that is about to flow through the circuit, and has the function of smoothing the change when the current tries to increase or decrease due to the switching operation. The reactor 1115 is the reactor 1 described above.
[0076] Vehicle 1200 is equipped with a converter 1110, a power supply device converter 1150 connected to the main battery 1210, and an auxiliary power converter 1160 connected to the main battery 1210 and a sub-battery 1230 which is a power source for auxiliary equipment 1240, and which converts the high voltage of the main battery 1210 to a low voltage. Converter 1110 typically performs DC-DC conversion, while the power supply device converter 1150 and the auxiliary power converter 1160 perform AC-DC conversion. Some power supply device converters 1150 also perform DC-DC conversion. The reactors of the power supply device converter 1150 and the auxiliary power converter 1160 have the same or similar configuration as the reactor 1 described above, and reactors with appropriately changed size and shape can be used. Furthermore, the reactor 1 described above can also be used in converters that convert input power, such as converters that only boost voltage or converters that only step down voltage.
[0077] 1 Reactor 2 Coil 21 First winding, 22 Second winding 31 First winding section, 32 Second winding section 41 First terminal section, 42 Second terminal section, 43 Third terminal section, 44 Fourth terminal section 411 First horizontal section, 412 First vertical section, 415 Tip section 421 Second horizontal section, 422 Second vertical section, 425 Tip section 45 Joint section 5 Envelope shape 51 Long side, 52 Short side 6 Magnetic core 71 First inner core section, 72 Second inner core section, 75 Outer surface 81 First outer core section, 82 Second outer core section 811 Top surface, 812 Bottom surface, 813, 814 Side surface, 815 Outer end surface 818 End region, 819 Notch 7S First virtual surface 9 Molded resin section 91 92 First end face resin part, 93, 94 Second end face resin parts, 935, 945 Side resin parts, 95 Outer surface, 95 Intermediate part, 9S Second virtual surface D1 First direction, D2 Second direction, D3 Third direction 1100 Power conversion device, 1110 Converter, 1111 Switching element 1112 Drive circuit, 1115 Reactor, 1120 Inverter 1150 Converter for power supply device, 1160 Converter for auxiliary power supply 1200 Vehicle, 1210 Main battery, 1220 Motor 1230 Sub-battery, 1240 Auxiliary equipment, 1250 Wheels, 1300 Engine
Claims
1. The device comprises a coil and a magnetic core, the coil comprising a first winding portion, a second winding portion, a first terminal portion, a second terminal portion, and a joint portion, the first winding portion being formed of a first winding wound in a helical manner, the second winding portion being formed of a second winding wound in a helical manner, the first winding portion and the second winding portion being arranged side by side such that the axes of the first winding portion and the axes of the second winding portion are parallel, each of the first winding portion and the second winding portion having a rectangular envelope shape that is elongated in a second direction along the direction in which the first winding portion and the second winding portion are aligned when viewed from a first direction along the axes of the first winding portion and the axes of the second winding portion, the first terminal portion comprising a first horizontal portion and a first vertical portion formed of the first winding drawn out from the first winding portion, the first horizontal portion extending from the first winding portion toward the second winding portion along the second direction, The first vertical portion extends from the end of the first horizontal portion along the first direction, the second terminal portion comprises a second horizontal portion and a second vertical portion formed by the second winding drawn out from the second winding portion, the second horizontal portion extends from the second winding portion along the second direction, the second vertical portion extends from the end of the second horizontal portion along the first direction, the joint portion is the location where the tip of the first vertical portion and the tip of the second vertical portion are connected, the magnetic core comprises a first inner core portion, a second inner core portion, a first outer core portion and a second outer core portion, the first inner core portion is disposed inside the first winding portion, the second inner core portion is disposed inside the second winding portion, and the first outer core portion is disposed facing the first end faces of the first winding portion and the second winding portion so as to be connected to the first ends of the first inner core portion and the second inner core portion, The second outer core portion is positioned facing the second end faces of the first winding portion and the second winding portion so as to be connected to the second ends of the first inner core portion and the second inner core portion, and the first vertical portion and the second vertical portion are located outward along the second direction from a first virtual plane that extends the outer surface of the second inner core portion, in a reactor.
2. The reactor according to claim 1, wherein the first outer core portion comprises an end region located outward along the second direction from the first virtual plane, and the end region comprises a notch that forms the arrangement space for the first vertical portion and the second vertical portion.
3. The reactor according to claim 1 or claim 2, comprising a molded resin portion that covers at least a portion of the first winding portion and the second winding portion and maintains the respective shapes of the first winding portion and the second winding portion.
4. The reactor according to claim 3, wherein the molded resin portion comprises a side resin portion that covers the outer surface of the second winding portion, and the first vertical portion and the second vertical portion are located between a second virtual surface, which is an extension of the outer surface of the side resin portion, and the first virtual surface.
5. The reactor according to claim 1 or claim 2, wherein the number of turns in the second winding portion is substantially one turn less than the number of turns in the first winding portion.
6. The reactor according to claim 1 or claim 2, wherein the ratio of the long side to the short side in the envelope shape is 2.5 or more.
7. A converter comprising the reactor described in claim 1 or claim 2.
8. A power conversion device comprising the converter described in claim 7.