JP7766866B2 - Reactor, magnetic core, converter, and power conversion device - Google Patents

Description

This disclosure relates to a reactor, a magnetic core, a converter, and a power conversion device.

The reactor in Patent Document 1 includes a coil and a magnetic core. The coil has a pair of winding portions formed by spirally winding a wire. Each winding portion has a rectangular cylindrical shape. The magnetic core has a pair of inner core portions and a pair of outer core portions. Each inner core portion is disposed inside the corresponding winding portion. Each inner core portion has a rectangular prism shape. Each outer core portion is disposed outside both winding portions.

JP 2013-219318 A

The reactor in Patent Document 1 is manufactured as follows: A pair of winding sections is prepared. Each inner core section is inserted into each winding section. Both inner cores and both outer core sections are fixed together. In order to insert each inner core section into each winding section, a gap is provided between the inner peripheral surface of each winding section and the outer peripheral surface of each inner core section. The presence of this gap makes it difficult to improve the heat dissipation performance of the inner core section.

One of the objects of the present disclosure is to provide a reactor that easily improves heat dissipation. One of the objects of the present disclosure is to provide a magnetic core that can be used to construct a reactor that easily improves heat dissipation. One of the objects of the present disclosure is to provide a converter that includes the reactor, and a power conversion device that includes the converter.

The reactor of the present disclosure includes:
a magnetic core having a core portion formed in a prismatic shape;
a coil having a winding portion disposed on an outer periphery of the core portion,
the core portion includes a first corner portion having a plurality of first recesses aligned along an axial direction of the core portion,
the winding portion is formed by a winding wound with a plurality of turns along the outer peripheral surface of the core portion,
The winding of each of the plurality of turns comprises:
a first linear portion that intersects the axial direction of the winding portion without being perpendicular thereto;
a second linear portion perpendicular to the axial direction of the winding portion;
a first bent portion connecting the first straight portion and the second straight portion,
The first bent portion in each of the plurality of turns is disposed in each of the plurality of first recesses.

The magnetic core of the present disclosure is
It has a prismatic core,
The core portion includes a first corner portion having a plurality of first recesses aligned along the axial direction of the core portion.

The converter of the present disclosure is equipped with the reactor of the present disclosure.

The power conversion device of the present disclosure includes the converter of the present disclosure.

The reactor of the present disclosure is easy to improve heat dissipation. The magnetic core of the present disclosure makes it easy to build a reactor with easy heat dissipation. The converter and power conversion device of the present disclosure have excellent heat dissipation properties.

FIG. 1 is a schematic perspective view showing a reactor according to a first embodiment. FIG. 2 is a schematic exploded perspective view showing the reactor of the first embodiment. FIG. 3 is a cross-sectional view taken along line III-III of FIG. FIG. 4 is an enlarged view of area A in FIG. FIG. 5 is an enlarged view of the VV cross section of FIG. FIG. 6 is a schematic perspective view showing a winding of a turn of a winding portion in the reactor of the first embodiment. FIG. 7 is an enlarged view showing grooves and windings in the reactor of the second embodiment. FIG. 8 is an enlarged view showing grooves and windings in the reactor of the third embodiment. FIG. 9 is an enlarged view showing grooves and windings in the reactor of the fourth embodiment. FIG. 10 is an enlarged view showing another example of the grooves and the windings in the reactor of the fourth embodiment. FIG. 11 is a schematic diagram showing the power supply system of a hybrid vehicle. FIG. 12 is a circuit diagram illustrating an example of a power conversion device including a converter.

<<Description of Embodiments of the Present Disclosure>>
The present inventors have investigated ways to improve heat dissipation by directly winding the windings constituting the coil around the core, thereby bringing the windings into contact with the core and transferring heat from the windings to the core. As a result, they have found that gaps are formed between the windings and the core at specific bends in each turn, reducing the contact area between the specific bends and the core. The present inventors have pursued extensive research into ways to increase the contact area between the specific bends and the core, and have completed the present invention. First, embodiments of the present disclosure will be described.

(1) A reactor according to an embodiment of the present disclosure includes:
a magnetic core having a core portion formed in a prismatic shape;
a coil having a winding portion disposed on an outer periphery of the core portion,
the core portion includes a first corner portion having a plurality of first recesses aligned along an axial direction of the core portion,
the winding portion is formed by a winding wound with a plurality of turns along the outer peripheral surface of the core portion,
The winding of each of the plurality of turns comprises:
a first linear portion that intersects the axial direction of the winding portion without being perpendicular thereto;
a second linear portion perpendicular to the axial direction of the winding portion;
a first bent portion connecting the first straight portion and the second straight portion,
The first bent portion in each of the plurality of turns is disposed in each of the plurality of first recesses.

The above configuration (1) is easier to improve heat dissipation than conventional reactors. In the above configuration (1), the winding of each turn is arranged along the outer peripheral surface of the core portion, which makes it easier to increase the contact area between the winding of each turn and the core portion compared to conventional reactors. Therefore, the above configuration (1) is easier to transfer heat from the winding to the core portion in addition to the object on which the reactor is installed compared to conventional reactors.

The configuration (1) above is more likely to improve heat dissipation than the reactor of the following reference example. Unlike the configuration (1) above, the reactor of the reference example has a winding wound around a core portion that does not have a first recess. The first bent portion of the winding is a location where the winding shifts axially as it bends. As a result, the first bent portion is twisted. In the reactor of the reference example, gaps are likely to form between the corners that do not have a first recess and the first bent portion. As a result, the contact area between the core portion and the first bent portion in the reactor of the reference example is likely to be small. On the other hand, in the configuration (1) above, the first bent portion is located in the first recess, so the contact area between the core portion and the first bent portion is likely to be large. Therefore, the configuration (1) above is more likely to transfer heat from the winding to the core portion than the reactor of the reference example.

(2) In the reactor of (1) above,
the core portion has a second corner portion adjacent to the first corner portion in a circumferential direction of the core portion,
the second corner portion has a plurality of second recesses aligned along the axial direction of the core portion,
The winding of each of the plurality of turns has a second bent portion connected to the first straight portion,
The second bent portion in each of the plurality of turns may be disposed in each of the plurality of second recesses.

The configuration (2) above is more likely to improve heat dissipation than when only the first recess is provided. The second bent portion is also twisted. The configuration (2) above tends to increase the contact area between the core portion and the second bent portion. Therefore, the configuration (2) above makes it easier to transfer heat from the winding to the core portion.

(3) In the reactor of (2) above,
The winding wire is a rectangular wire,
A cross-sectional shape of each of the plurality of first recesses and each of the plurality of second recesses taken along the axial direction may be triangular.

The configuration (3) above makes it easy to place the winding in the first recess and the second recess, which tends to increase the contact area between the core and the winding. Therefore, the configuration (3) above makes it easy to transfer heat from the winding to the core.

(4) In the reactor of (3),
The wound portion may be formed by winding the rectangular wire flatwise.

The configuration (4) above makes it easier to bend the rectangular wire than the configuration (5) described below, making it easier to fabricate the first and second winding sections.

(5) In the reactor of (3),
The wound portion may be formed by edgewise winding the rectangular wire.

When the axial length of the winding portion is constant, the configuration (5) above makes it easier to increase the number of turns in the winding portion compared to the configuration (4). When the number of turns in the winding portion is constant, the configuration (5) above makes it easier to shorten the axial length of the winding portion compared to the configuration (4). Therefore, the configuration (5) above is easier to miniaturize compared to the configuration (4).

(6) In any one of the reactors (1) to (5),
The core portion has a quadrangular prism shape,
The wound portion may be in the shape of a square tube.

The configuration (6) above is easy to manufacture because it is easy to wind the winding along the outer peripheral surface of the core portion during the manufacturing process. The configuration (6) above makes it easier to increase the contact area between the winding portion and the object on which the reactor is installed, compared to when the winding portion is a circular cylinder of the same cross-sectional area. Therefore, the configuration (6) above makes it easier to transfer heat from the winding portion to the object on which it is installed. Furthermore, the configuration (6) above makes it easier to stably install the winding portion on the object on which it is installed.

(7) In any one of the reactors (1) to (6),
The core portion is
a core body portion mainly made of a magnetic material;
an insulating portion provided along an outer circumferential surface of the core body portion,
The plurality of first recesses may be provided in the insulating portion.

In the configuration (7) above, the insulating portion makes it easier to improve the insulation between the core body and the winding portion, compared to when the core is composed only of the core body without the insulating portion.

(8) A magnetic core according to an embodiment of the present disclosure includes:
It has a prismatic core,
The core portion includes a first corner portion having a plurality of first recesses aligned along the axial direction of the core portion.

The configuration (8) above makes it easier to build a reactor with improved heat dissipation for the reasons explained in the configuration (1) above.

(9) In the magnetic core of (8),
the core portion has a second corner portion adjacent to the first corner portion in a circumferential direction of the core portion,
The second corner portion may have a plurality of second recesses aligned along the axial direction of the core portion.

For the reasons explained in the configuration (2) above, the configuration (9) above makes it easier to construct a reactor with improved heat dissipation compared to a configuration that only has a first recess.

(10) A converter according to an embodiment of the present disclosure includes:
The reactor according to any one of (1) to (7) above is included.

The converter has excellent heat dissipation properties due to the reactor.

(11) A power conversion device according to an embodiment of the present disclosure includes:
The converter (10) is provided.

The above power conversion device has excellent heat dissipation properties because it is equipped with the above converter.

Details of the embodiments of the present disclosure
[0023] The details of the embodiments of the present disclosure will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same objects. The sizes of the components shown in the drawings are expressed for the purpose of clarifying the description and do not necessarily represent the actual dimensional relationships.

First Embodiment
[Reactor]
A reactor 1 of the first embodiment will be described with reference to Figures 1 to 6. The reactor 1 includes a coil 2 and a magnetic core 3. As shown in Figure 2, the magnetic core 3 has a core portion 30. The core portion 30 has a rectangular columnar shape. The coil 2 has a winding portion 20. The winding portion 20 is disposed on the outer periphery of the core portion 30. One of the features of the reactor 1 of this embodiment is that it satisfies the following requirements (A) to (C).
(A) The core portion 30 includes a first corner portion 311. The first corner portion 311 has a plurality of first recesses 312 aligned along the axial direction of the core portion 30, as shown in FIGS.
(B) The winding portion 20 is composed of a winding 21 wound in a plurality of turns along the outer peripheral surface of the core portion 30 .
(C) The first bent portion 213 of each turn of the winding 21 shown in FIG. 6 is disposed in each of the first recesses 312 shown in FIGS.

[Magnetic core]
The magnetic core 3 of this embodiment shown in FIG. 2 includes a first middle core portion 31f, a second middle core portion 31s, a first end core portion 33f, and a second end core portion 33s. The core portion 30 of this embodiment constitutes each of the first middle core portion 31f and the second middle core portion 31s. Unlike the fourth embodiment, the core portion 30 of this embodiment, i.e., each of the first middle core portion 31f and the second middle core portion 31s, does not include an insulating portion 30b, which will be described later with reference to FIGS. 9 and 10 , and is instead composed of a core body portion 30a primarily made of a magnetic material. The core body portion 30a is composed of a molded body or laminate, which will be described later. The first end core portion 33f and the second end core portion 33s are each composed of a molded body or laminate independent of the first middle core portion 31f and the second middle core portion 31s.

The first middle core portion 31f, the second middle core portion 31s, the first end core portion 33f, and the second end core portion 33s are combined in an annular shape. The first end face of the first middle core portion 31f faces the inner end face of the first end core portion 33f. The second end face of the first middle core portion 31f faces the inner end face of the second end core portion 33s. The first end face of the second middle core portion 31s faces the inner end face of the first end core portion 33f. The second end face of the second middle core portion 31s faces the inner end face of the first end core portion 33f. Gap materials, as described below, may be arranged between the first middle core portion 31f and the first end core portion 33f, between the first middle core portion 31f and the second end core portion 33s, between the second middle core portion 31s and the first end core portion 33f, and between the second middle core portion 31s and the second end core portion 33s.

The first middle core portion 31f and the second middle core portion 31s have the same configuration. The first end core portion 33f and the second end core portion 33s have the same configuration. The following explanation will focus on the first middle core portion 31f and the first end core portion 33f as representative examples.

The first middle core portion 31f has a rectangular prism shape. In this embodiment, the first middle core portion 31f has a quadrangular prism shape. The four corners of the quadrangular prism are rounded. In other words, the outer peripheral surface of the first middle core portion 31f, excluding the first end face and second end face, is composed of four flat surfaces and four corners.

One of the four corners is a first corner 311. As shown in Figures 2 to 4, the first corner 311 has multiple first recesses 312 aligned along the axial direction of the first middle core portion 31f. The multiple first recesses 312 are continuous in the axial direction. A first bent portion 213 of the winding 21 in each turn of the first winding portion 2i, described below with reference to Figure 6, is located in each first recess 312. The cross-sectional shape of each first recess 312 cut along the axial direction can be appropriately selected depending on the cross-sectional shape of the winding 21. As described below, the winding 21 of this embodiment is a coated rectangular wire. As shown in Figures 3 and 4, the cross-sectional shape of each first recess 312 of this embodiment is triangular. More specifically, the cross-sectional shape of each first recess 312 is a right-angled triangle. Note that in Figure 4, the cross-sectional shape of each first recess 312 is not depicted as a right-angled triangle, and the cross-section of the winding 21 is not depicted as a rectangle. This is because the first recess 312 extends in a twisted manner along the first bent portion 213. This is also the case in Figure 7, which will be described later.

The two adjacent sides forming a right angle of the right triangle are the first adjacent side facing the short side of the winding 21 and the second adjacent side facing the long side of the winding 21. As described below, the first winding portion 2i of this embodiment is formed by edgewise winding a coated rectangular wire. The length of the first adjacent side of this embodiment is substantially the same as the short side of the winding 21. The length of the second adjacent side of this embodiment is shorter than the long side of the winding 21. Figure 5 shows a cross-sectional view taken along a plane that passes through the apex of the right angle of the right triangle and is perpendicular to the axial direction. As shown in Figure 5, the circumferential center of the first recess 312 is the deepest, and the circumferential ends of the first recess 312 are shallowest. The circumferential ends of the first recess 312 are flush with both planes adjacent to the first corner portion 311.

In this embodiment, as shown in FIG. 2, one of the two corners adjacent to the first corner 311 in the circumferential direction of the first middle core portion 31f is the second corner 313. The second corner 313 has multiple second recesses 314 lined up along the axial direction. In each second recess 314, a second bent portion 214 of each turn of the winding 21, which will be described later with reference to FIG. 6, is disposed. The multiple second recesses 314 are continuous in the axial direction. The configuration of each second recess 314 is the same as that of the first recess 312.

In this embodiment, the remaining two corners are third corners 315. The third corners 315 are corners that do not have the first recesses 312 or second recesses 314 and are formed by arc surfaces.

Unlike this embodiment, one of the four corners may be a first corner 311 and the remaining three corners may be third corners 315.

The first end core portion 33f has a columnar shape. In this embodiment, the first end core portion 33f has a columnar shape with approximately dome-shaped upper and lower surfaces.

The first middle core portion 31f and the first end core portion 33f are composed of a composite material molded body, a powder compact, or a laminate.

A composite material compact is a compact in which soft magnetic powder is dispersed in resin. A composite material compact is obtained by filling a mold with a fluid material in which soft magnetic powder is dispersed in unsolidified resin and then solidifying the resin. A composite material compact with first recesses 312 and second recesses 314 formed can be produced by mold transfer. The content of soft magnetic powder in the resin of a composite material compact can be easily adjusted. This makes it easy to adjust the magnetic properties of a composite material compact. Furthermore, compared to pressed powder compacts, composite material compacts can be easily formed into complex shapes. An example of the soft magnetic powder content in a composite material compact is 20% by volume or more and 80% by volume or less. An example of the resin content in a composite material compact is 20% by volume or more and 80% by volume or less. These contents are values when the composite material compact is 100% by volume.

A powder compact is a compact formed by compressing soft magnetic powder. A powder compact is obtained by filling a cavity with soft magnetic powder and applying pressure to the soft magnetic powder in the cavity with a punch. A powder compact having a first recess 312 and a second recess 314 can be produced by transfer using at least one of a cavity and a punch. A powder compact can have a higher proportion of soft magnetic powder in the core portion 30 than a composite material compact. Therefore, the powder compact can easily improve its magnetic properties. Examples of magnetic properties include relative permeability and saturation magnetic flux density. Furthermore, a powder compact has a higher amount of soft magnetic powder than a composite material compact, resulting in superior heat dissipation. An example of the magnetic powder content in a powder compact is 85% by volume or more and 99% by volume or less. This content is the value when the powder compact is 100% by volume.

The particles that make up the soft magnetic powder may be soft magnetic metal particles, coated particles, or soft magnetic non-metal particles. The coated particles may comprise soft magnetic metal particles and an insulating coating formed around the soft magnetic metal particles. The soft magnetic metal may be 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 non-metal is ferrite.

Examples of resins used in composite moldings 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.

The composite material compact may contain a filler. Examples of fillers include alumina and silica. The filler contributes to improving heat dissipation and electrical insulation.

The content of soft magnetic powder in a composite material compact and the content of soft magnetic powder in a powder compact are considered to be equivalent to the area ratio of the soft magnetic powder in the cross section of the compact. The content of soft magnetic powder in the compact is determined as follows: The cross section of the compact is observed with an SEM (scanning electron microscope) to obtain an observation image. The cross section of the compact is any cross section. The magnification of the SEM is 200 times or more and 500 times or less. The number of observation images obtained is 10 or more. The total area of all observation images is 0.1 ^cm2 or more. One observation image may be obtained per cross section, or multiple observation images may be obtained per cross section. Each obtained observation image is subjected to image processing to extract the particle outlines. Image processing may be, for example, binarization. The area ratio of soft magnetic particles in each observation image is calculated, and the average of these area ratios is determined. This average is considered to be the soft magnetic powder content.

The laminate is made by stacking multiple magnetic thin plates. The magnetic thin plates have an insulating coating. Examples of magnetic thin plates include electromagnetic steel plates. A laminate with a first recess 312 and a second recess 314 can be produced by stacking multiple magnetic thin plates of different areas in the thickness direction of the magnetic thin plates.

In this embodiment, the first middle core portion 31f, second middle core portion 31s, first end core portion 33f, and second end core portion 33s are composed of a molded body made of a composite material.

(Gap material)
The gap material is made of a material having a lower relative magnetic permeability than the first middle core portion 31 f, the second middle core portion 31 s, the first end core portion 33 f, and the second end core portion 33 s. Examples of materials for the gap material include the above-mentioned ceramics and resin.

[coil]
The coil 2 of this embodiment shown in FIG. 2 has a first winding portion 2i and a second winding portion 2e. The winding portion 20 of this embodiment constitutes each of the first winding portion 2i and the second winding portion 2e. The first winding portion 2i and the second winding portion 2e may or may not be connected to each other. The first winding portion 2i is disposed on the outer periphery of the first middle core portion 31f. The second winding portion 2e is disposed on the outer periphery of the second middle core portion 31s. The first winding portion 2i and the second winding portion 2e have the same configuration. The following description will be given representatively of the first winding portion 2i.

The first winding portion 2i has a rectangular cylindrical shape. The corners of the first winding portion 2i are rounded. The first winding portion 2i is composed of a winding 21. The winding 21 is wound with multiple turns along the outer peripheral surface of the first middle core portion 31f. The rectangular cylindrical first winding portion 2i is easy to manufacture because it is easy to wind the winding 21 along the outer peripheral surface of the first middle core portion 31f during the manufacturing process. A known winding can be used for the winding 21. In this embodiment, the winding 21 is a coated rectangular wire. The conductor wire of the coated rectangular wire is made of a copper rectangular wire. The insulating coating of the coated rectangular wire is made of enamel. The first winding portion 2i is formed by edgewise winding the coated rectangular wire. When the axial length of the first winding portion 2i is constant, an edgewise wound first winding portion 2i can easily have a larger number of turns than a flatwise wound first winding portion 2i. When the number of turns in the first winding portion 2i is constant, the edgewise wound first winding portion 2i is easier to shorten in length along the axial direction than the flatwise wound first winding portion 2i. Therefore, the edgewise wound first winding portion 2i is easier to make smaller than the flatwise wound first winding portion 2i. The winding 21 of each turn of the first winding portion 2i is composed of four straight portions and four bent portions.

As shown in FIG. 6 , the four straight portions in this embodiment are one first straight portion 211 and three second straight portions 212. The four bent portions in this embodiment are one first bent portion 213, one second bent portion 214, and two third bent portions 215. The first straight portion 211 intersects the axial direction of the first winding portion 2i without being perpendicular thereto. The second straight portion 212 is perpendicular to the axial direction of the first winding portion 2i. The first bent portion 213 connects the first straight portion 211 and the second straight portion 212. The second bent portion 214 connects the first straight portion 211 and the second straight portion 212 of the adjacent turn. The first bent portion 213 and the second bent portion 214 are locations where the winding 21 is displaced in the axial direction of the first winding portion 2i as it bends. In other words, the first bent portion 213 and the second bent portion 214 are twisted. The third bent portions 215 connect the second straight portions 212 together. The third bent portions 215 are locations where the winding 21 bends but does not shift in the axial direction of the first winding portion 2i. In other words, the third bent portions 215 are not twisted. Unlike this embodiment, the four bent portions may be one first bent portion 213 and three third bent portions 215.

Each first straight portion 211 is in contact with the plane connecting the first corner 311 and the second corner 313. The three second straight portions 212 of each turn are in contact with the plane connecting the first corner 311 and the third corner 315, the plane connecting the second corner 313 and the third corner 315, and the plane connecting the third corners 315 together. Heat from the winding 21 where each first straight portion 211 and each second straight portion 212 is in contact with the first middle core portion 31f is easily transferred to the first middle core portion 31f. Therefore, the reactor 1 of this embodiment has improved heat dissipation properties compared to conventional reactors in which a gap is formed between the first winding portion 2i and the first middle core portion 31f.

Each first bent portion 213 is disposed in a respective first recess 312. Each first bent portion 213 is in contact with a first corner portion 311. Each second bent portion 214 is disposed in a respective second recess 314. Each second bent portion 214 is in contact with a second corner portion 313. The two third bent portions 215 of each turn are in contact with each third corner portion 315.

The reactor 1 of this embodiment, in which each first bent portion 213 is disposed in each first recess 312 and each second bent portion 214 is disposed in each second recess 314, is more likely to have improved heat dissipation than the reactor of the following reference example. Unlike this embodiment, the reactor of the reference example has the winding 21 wound around the first middle core portion 31f, which does not have the first recess 312 or second recess 314. In the reactor of the reference example, gaps are likely to form between each twisted first bent portion 213 and the third corner portion 315, and between each twisted second bent portion 214 and the third corner portion 315. Therefore, the contact area between the first bent portion 213 and the second bent portion 214 and the first middle core portion 31f in the reactor of the reference example is likely to be small. On the other hand, in this embodiment, each first bent portion 213 is disposed in each first recess 312, and each second bent portion 214 is disposed in each second recess 314. This tends to increase the contact area between each first bent portion 213 and each second bent portion 214 and the first middle core portion 31f. Therefore, the reactor 1 of this embodiment is more likely to transfer heat from the winding 21 to the first middle core portion 31f than the reactor of the reference example.

Each third bent portion 215 contacts a third corner portion 315. Unlike the first bent portions 213, each third bent portion 215 is not twisted, so contact is easy even with the third corner portion 315, which is a curved surface without a recess.

The first winding portion 2i is produced by winding the winding 21 along the outer peripheral surface of the first middle core portion 31f. During the production process, the first bent portion 213 is aligned with the first recess 312, and the second bent portion 214 is aligned with the second recess 314.

Other Embodiments
Reactors according to embodiments 2 to 5, which are different from embodiment 1, will be described. The description of embodiments 2 to 5 will focus on the differences from embodiment 1. The description of the same configuration as embodiment 1 may be omitted.

Second Embodiment
As shown in FIG. 7 , in the reactor of embodiment 2, the first winding portion 2i and the second winding portion 2e may be configured by flatwise winding a coated rectangular wire. Flatwise wound first winding portion 2i and second winding portion 2e are easier to manufacture because the coated rectangular wire is easier to bend than edgewise wound first winding portion 2i and second winding portion 2e. In this embodiment, the cross-sectional shape of each first recess 312 and each second recess 314 is a right triangle, as in embodiment 1. In this embodiment, the length of the second adjacent side, which faces the long side of the winding 21, of the two adjacent sides forming a right angle of the right triangle, is substantially the same as the long side of the winding 21. The length of the first adjacent side, which faces the short side of the winding 21, of the two adjacent sides of the right triangle, is shorter than the short side of the winding 21.

Third Embodiment
As shown in FIG. 8, in the reactor of the third embodiment, the cross-sectional shape of each of the first recesses 312 and each of the second recesses 314 may be semicircular, and the winding 21 may be a round wire.

Fourth Embodiment
As shown in Figures 9 and 10, in the reactor of embodiment 4, the core portion 30 may include a core body portion 30a and an insulating portion 30b provided along the outer peripheral surface of the core body portion 30a. The insulating portion 30b tends to improve the insulation between the core body portion 30a and the winding portion 20. The core body portion 30a is made of the above-mentioned molded body or laminate. The insulating portion 30b is made of, for example, the same resin as the resin of the above-mentioned composite material molded body. In this embodiment, the core body portion 30a and the insulating portion 30b are integrated. Unlike this embodiment, the core body portion 30a and the insulating portion 30b may be independent of each other.

In this embodiment, the core body 30a is rectangular prism-shaped. The outer peripheral surface of the core body 30a is composed of four flat surfaces and four corners.

As shown in FIG. 9, one of the four corners of the core body 30a may have multiple recesses 318 lined up along the axial direction of the core body 30a. Although not shown, one of the two corners circumferentially adjacent to the corner with multiple recesses 318 on the core body 30a may also have multiple recesses 318. The remaining two corners are corners formed by arc surfaces.

As shown in FIG. 9 , the insulating portion 30b has a first corner 311 in which the above-described multiple first recesses 312 are provided. The first corner 311 of the insulating portion 30b is provided so as to cover one of the four corners of the core body portion 30a in which the multiple recesses 318 are provided. The first recess 312 of the insulating portion 30b is aligned with the recess 318 of the core body portion 30a. Although not shown, the insulating portion 30b may further have a second corner in which the above-described multiple second recesses are provided. The second corner of the insulating portion 30b is provided so as to cover the corner in which the multiple recesses 318 are provided, of two corners of the core body portion 30a adjacent in the circumferential direction to the corner in which the multiple recesses 318 are covered by the first corner 311. The second recess of the insulating portion 30b is aligned with the recess 318 covered by the second corner. In addition to the above two corners of the core body portion 30a, the insulating portion 30b may also cover the remaining two corners. Furthermore, the insulating portion 30b may cover all four flat surfaces of the core body portion 30a. In other words, the insulating portion 30b may be provided so as to cover the entire outer periphery of the core body portion 30a.

Unlike the example shown in Fig. 9 , as shown in Fig. 10 , none of the four corners of the core body 30a have the plurality of recesses 318, and may be corners formed by arcuate surfaces. As shown in Fig. 10 , the first corner 311 of the insulating portion 30b, in which the plurality of first recesses 312 described above are provided, may be provided so as to cover the corner of the core body 30a formed by arcuate surfaces. Although not shown, the second corner of the insulating portion 30b, in which the plurality of second recesses described above are provided, may be provided so as to cover one of two corners of the core body 30a that are circumferentially adjacent to the corner covered by the first corner 311.

Fifth Embodiment
Although not shown, in the reactor of embodiment 5, the magnetic core may have a middle core portion, a first side core portion, a second side core portion, a first end core portion, and a second end core portion. The middle core portion, the first side core portion, and the second side core portion are arranged side by side so that their axial directions are parallel to each other. The middle core portion is arranged between the first side core portion and the second side core portion. The first side core portion is arranged facing the first end face of the middle core portion, the first end face of the first side core portion, and the first end face of the second side core portion. The second side core portion is arranged facing the second end face of the middle core portion, the second end face of the first side core portion, and the second end face of the second side core portion.

The magnetic core can be constructed, for example, by combining E-shaped first core pieces with I-shaped second core pieces, or by combining U-shaped first core pieces with T-shaped second core pieces. The E-shaped first core pieces are a molded body or laminated body in which the middle core portion, first side core portion, second side core portion, and first end core portion are integrated. The I-shaped second core pieces are constructed from the second end core portion. The U-shaped first core pieces are a molded body or laminated body in which the first side core portion, second side core portion, and first end core portion are integrated. The T-shaped second core pieces are a molded body or laminated body in which the middle core portion and second end core portion are integrated.

In this embodiment, the core portion 30 described in the first embodiment may constitute both the first side core portion and the second side core portion. The first winding portion 2i described above may be arranged on the outer periphery of the first side core portion, and the second winding portion 2e described above may be arranged on the outer periphery of the second side core portion. The first winding portion 2i and the second winding portion 2e may be independent of each other.

Sixth Embodiment
[Converter/Power Conversion Device]
The reactor 1 according to any one of the first to fifth embodiments can be used in applications that satisfy the following energization conditions. The energization conditions include, for example, a maximum DC current of approximately 100 A to 1000 A, an average voltage of approximately 100 V to 1000 V, and an operating frequency of approximately 5 kHz to 100 kHz. The reactor 1 according to any one of the first to fifth embodiments can be 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 including this converter.

As shown in FIG. 11, the vehicle 1200 includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and a motor 1220 that is driven by power supplied from the main battery 1210 and used for traveling. The motor 1220 is typically a three-phase AC motor that drives the wheels 1250 when traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 includes an engine 1300 in addition to the motor 1220. While FIG. 11 shows an inlet as the charging point for the vehicle 1200, a plug may also be provided.

The power conversion device 1100 has a converter 1110 connected to the main battery 1210, and an inverter 1120 connected to the converter 1110 and converting DC to AC or vice versa. The converter 1110 shown in this example 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, 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 it to the motor 1220, and when regenerating, it converts the AC output from the motor 1220 into DC and outputs it to the converter 1110.

As shown in FIG. 12, the converter 1110 includes multiple 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 them on and off. In this case, the conversion of the input voltage refers to boosting or bucking the voltage. The switching elements 1111 are power devices such as field-effect transistors and insulated gate bipolar transistors. The reactor 1115 utilizes the properties of a coil that hinders changes in current flowing through the circuit, and has the function of smoothing changes when the current attempts to increase or decrease due to switching operation. The reactor 1115 includes the reactor 1 of any of embodiments 1 to 5. A power conversion device 1100 and a converter 1110 that include the reactor 1 are expected to have improved heat dissipation properties.

In addition to converter 1110, vehicle 1200 is equipped with a power supply converter 1150 connected to main battery 1210, and an auxiliary power supply converter 1160 connected to main battery 1210 and sub-battery 1230, which serves as a power source for auxiliary equipment 1240, and converts the high voltage of main battery 1210 to low voltage. Converter 1110 typically performs DC-DC conversion, while power supply converter 1150 and auxiliary power supply converter 1160 perform AC-DC conversion. Some power supply converters 1150 perform DC-DC conversion. The reactor of power supply converter 1150 and auxiliary power supply converter 1160 can have a configuration similar to reactor 1 in any of embodiments 1 to 5, but can be a reactor with modified size, shape, etc. as appropriate. Furthermore, the reactor 1 of any of embodiments 1 to 5 can also be used in converters that convert input power, such as converters that only step up or converters that only step down.

The present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

DESCRIPTION OF SYMBOLS 1 Reactor 2 Coil 20 Winding portion, 2i First winding portion, 2e Second winding portion 21 Winding 211 First straight portion, 212 Second straight portion 213 First bent portion, 214 Second bent portion, 215 Third bent portion 3 Magnetic core, 30 Core portion 30a Core body portion , 30b Insulating portion 31f First middle core portion, 31s Second middle core portion 311 First corner portion, 312 First recess 313 Second corner portion, 314 Second recess 315 Third corner portion 318 Recess 33f First end core portion, 33s Second end core portion 1100 Power conversion device, 1110 Converter 1111 Switching element, 1112 Drive circuit, 1115 Reactor 1120 Inverter 1150 Power supply device converter, 1160 Auxiliary power supply converter 1200 Vehicle 1210 Main battery, 1220 Motor, 1230 Sub-battery 1240 Auxiliary equipment, 1250 Wheels 1300 Engine

Claims (8)

a magnetic core having a core portion formed in a prismatic shape;
a coil having a winding portion disposed on an outer periphery of the core portion,
the core portion includes a first corner portion having a plurality of first recesses arranged continuously in a direction along the axis of the core portion,
the winding portion is formed by a winding wound with a plurality of turns along the outer peripheral surface of the core portion,
The winding wire is a rectangular wire,
The winding portion is formed by winding the flat wire edgewise,
The cross-sectional shape of the first recess is triangular,
the two adjacent sides forming the triangle are a first adjacent side facing a short side of the winding and a second adjacent side facing a long side of the winding,
The length of the first adjacent side is the same as the short side of the winding, and the length of the second adjacent side is shorter than the long side of the winding,
The winding of each of the plurality of turns comprises:
a first linear portion that intersects a direction along the axis of the winding portion without being perpendicular thereto;
a second linear portion perpendicular to the direction along the axis of the winding portion;
a first bent portion connecting the first straight portion and the second straight portion,
the first bent portion in each of the plurality of turns is disposed in each of the plurality of first recesses;
Reactor. a magnetic core having a core portion formed in a prismatic shape;
a coil having a winding portion disposed on an outer periphery of the core portion,
the core portion includes a first corner portion having a plurality of first recesses arranged continuously in a direction along the axis of the core portion,
the winding portion is formed by a winding wound with a plurality of turns along the outer peripheral surface of the core portion,
The winding wire is a rectangular wire,
The winding portion is formed by winding the rectangular wire flatwise,
The cross-sectional shape of the first recess is triangular,
the two adjacent sides forming the triangle are a first adjacent side facing a short side of the winding and a second adjacent side facing a long side of the winding,
the length of the second adjacent side is the same as the long side of the winding, and the length of the first adjacent side is shorter than the short side of the winding;
The winding of each of the plurality of turns comprises:
a first linear portion that intersects a direction along the axis of the winding portion without being perpendicular thereto;
a second linear portion perpendicular to the direction along the axis of the winding portion;
a first bent portion connecting the first straight portion and the second straight portion,
the first bent portion in each of the plurality of turns is disposed in each of the plurality of first recesses;
Reactor. the core portion has a second corner portion adjacent to the first corner portion in a direction around the axis of the core portion,
the second corner portion has a plurality of second recesses that are aligned continuously in a direction along the axis of the core portion,
The cross-sectional shape of the second recess is triangular,
the two adjacent sides forming the triangle are a first adjacent side facing a short side of the winding and a second adjacent side facing a long side of the winding,
The winding of each of the plurality of turns has a second bent portion connected to the first straight portion,
The reactor according to claim 1 or 2 , wherein the second bent portion in each of the plurality of turns is disposed in each of the plurality of second recesses. The reactor according to claim 1 or 2, wherein a cross-sectional shape of the first recess is a right-angled triangle. The reactor according to claim 3 , wherein a cross-sectional shape of the second recess is a right-angled triangle. The core portion has a quadrangular prism shape,
The reactor according to claim 1 or 2, wherein the winding portion has a rectangular cylindrical shape. A reactor according to claim 1 or 2 is provided.
converter. A converter according to claim 7 ,
Power conversion device.