Magnetic coupling reactor and assembly method therefor

Abstract

A magnetic coupling reactor 100 includes: an outer peripheral core 130 including E-type cores 110 or the like equipped with a first magnetic outer peripheral wall 140 or the like, a second magnetic outer peripheral wall 150a or the like curved from both ends thereof, a third magnetic outer peripheral wall 150b or the like, and a magnetic middle leg section 150c or the like erected on an inner surface of the first magnetic outer peripheral wall 140 or the like, in which the outer peripheral core 130 is formed in a hexagonal shape by causing the end sections of the second magnetic outer peripheral walls 150a or the like and the end sections of the third magnetic outer peripheral walls 150b or the like to abut each other in adjacent E-type cores 110 or the like among three E-type cores 110 or the like and thereby arranging said E-type cores 110 or the like in the peripheral direction; a Y-type core 160 in which a gap is left between the three magnetic middle leg sections 150c or the like and constricted parts 161 are arranged facing each other in a space formed by central parts 135 with each of the magnetic middle leg sections 150c or the like extending toward the central parts 135; and a coil 170 or the like wound around each of the magnetic middle leg sections 150c or the like.

Description

Magnetic coupling reactor and its assembly method

[0001] The present invention relates to a magnetic coupling reactor mounted on the electronic circuits of various devices and an assembly method thereof, and more particularly to the shape of a magnetic core constituting the magnetic coupling reactor.

[0002] A known conventional magnetic coupling reactor is a three-phase magnetic coupling reactor 305, as shown in FIG. 11 (corresponding to FIG. 1A of Patent Document 1 below). The three cores 341-343 extend from the inner periphery of an annular outer core 320 toward the center. Coils 351-353 are wound around the cores 341-343, respectively. The tip ends of the cores 341-343 are located near the center of the annular outer core 320 and face each other, forming magnetically connectable gaps 301-303. Note that FIG. 11 shows three core coil portions 331-333. For example, a known conventional three-phase magnetic coupling reactor 305 includes coils 270-272 attached to center legs 250c-252c of E-shaped cores 210-212, as shown in FIG. 4A (see Patent Document 1 below). Since each of the E-shaped cores 210 to 212 is an open magnetic circuit by itself, the magnetic flux generated from the coil of one phase circulates from the corresponding center leg 250c (which corresponds to, for example, iron core 341 in Figure 11) through the center legs 251c and 252c of the other phase (which correspond to, for example, iron cores 342 and 343 in Figure 11), thereby forming two closed magnetic circuits.

[0003] Patent No. 6450717

[0004] However, the gaps 301 to 303 that exist within each closed magnetic circuit shown in FIG. 11 are only located at one location between the tip ends of the opposing iron cores 341 to 343, and adjusting the width of these gaps 301 to 303 affects both the inductance and leakage inductance at the same time, making it difficult to adjust the inductance and leakage inductance to any desired value.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic coupling reactor in which the inductance and leakage inductance can be easily adjusted independently, and a method for assembling the same.

[0006] A first magnetic coupling reactor of the present invention is characterized by comprising: an outer core having a 2N-sided polygonal cross section formed by circumferentially arranging N E-shaped magnetic members, each having a substantially E-shape in plan view, with the N E-shaped magnetic members including a first magnetic outer peripheral wall formed in a flat plate shape with a predetermined thickness, second and third magnetic outer peripheral walls curved symmetrically from both ends of the first magnetic outer peripheral wall at a predetermined angle, and a magnetic center leg erected on the inner surface of the first magnetic outer peripheral wall, with the end of the second magnetic outer peripheral wall and the end of the third magnetic outer peripheral wall of adjacent E-shaped magnetic members butting against each other; a multi-leg core having N legs radially arranged, the N magnetic center legs extending toward the central portion of the outer core and positioned opposite the ends of the N magnetic center legs with a predetermined gap between them; and a coil wound around each of the magnetic center legs (where N is a natural number greater than or equal to 3).

[0007] Furthermore, a second magnetic coupling reactor of the present invention is characterized in having: an outer core having a hexagonal cross section, which is formed by arranging three E-shaped cores, each having a substantially E-shape in plan view, in the circumferential direction with the end of the second magnetic outer wall and the end of the third magnetic outer wall of adjacent E-shaped cores butting against each other, the E-shaped cores including a first magnetic outer peripheral wall formed in a flat plate shape with a predetermined thickness, a second magnetic outer peripheral wall and a third magnetic outer peripheral wall curved at a predetermined angle from both ends of the first magnetic outer peripheral wall so as to form symmetrical shapes with respect to each other, and a magnetic center leg erected on the inner surface of the first magnetic outer peripheral wall; an outer core having a substantially E-shape in plan view, the E-shaped cores including a first magnetic outer peripheral wall formed in a flat plate shape with a predetermined thickness, a second magnetic outer peripheral wall and a third magnetic outer peripheral wall curved at a predetermined angle from both ends of the first magnetic outer peripheral wall so as to form symmetrical shapes with each other, and a magnetic center leg erected on the inner surface of the first magnetic outer peripheral wall; an outer core having a Y-shape in overall view, in which each of the magnetic center legs extends toward a central portion of the outer core, and constricted portions are arranged opposite each other with a predetermined gap between them and the tips of the three magnetic center legs in a space formed in the central portion; and a coil wound around each of the magnetic center legs.

[0008] In the second magnetic coupling reactor, the second magnetic outer peripheral wall and the third magnetic outer peripheral wall are preferably arranged to protrude inward. In the second magnetic coupling reactor, the Y-shaped core is preferably formed by adjacently arranging a plurality of core members to have a Y-shape.

[0009] Furthermore, in the second magnetic coupling reactor, the outer core may have a cross section in a concave hexagonal shape. Also, in any of the second magnetic coupling reactors, it is preferable that the legs extending in three directions of the Y-shaped core are arranged opposite to a portion where an end of the second magnetic outer wall and an end of the third magnetic outer wall are butted together, with a predetermined gap therebetween.

[0010] Furthermore, a method for assembling a magnetic coupling reactor of the present invention includes preparing three E-shaped cores having a generally E-shape in top view, the E-shaped cores including a first magnetic outer circumferential wall formed in a flat plate shape with a predetermined thickness, second and third magnetic outer circumferential walls curved at a predetermined angle from both ends of the first magnetic outer circumferential wall so as to form symmetrical shapes with respect to each other, and a magnetic center leg erected on the inner surface of the first magnetic outer circumferential wall, connecting and fixing a wound coil to each of the magnetic center legs of the three E-shaped cores, assembling the E-shaped cores in the circumferential direction by butting the ends of the second and third magnetic outer circumferential walls of adjacent E-shaped cores together, and arranging the E-shaped cores in the circumferential direction so that the ends of the second and third magnetic outer circumferential walls of adjacent E-shaped cores are butted against each other, and assembling an outer circumferential core having a hexagonal cross section, and disposing a Y-shaped core having a Y-shape in overall view in a space formed in the central portion of the outer circumferential core with each of the magnetic center legs extending toward the central portion of the outer circumferential core so that constricted portions are arranged opposite each other with a predetermined gap between them and the tips of the three magnetic center legs, In order to adjust the amount of the gap so as to reduce the difference in characteristics between the three coils, the position of the Y-shaped core is moved within the space, and the E-shaped core and the Y-shaped core are temporarily fixed together; the magnetic coupling reactor body including the E-shaped core, the coils, and the Y-shaped core is housed in a specified case, and the case is filled with resin for final fixation.

[0011] Furthermore, in the method for assembling the magnetic coupling reactor, it is preferable that the Y-shaped core is positioned opposite the portion where the end of the second magnetic outer wall and the end of the third magnetic outer wall are butted together, with a predetermined gap therebetween.

[0012] In the magnetic coupling reactor of the present invention, each phase is configured with the equivalent of a closed magnetic circuit of an EI-type core, and in a combination of these, for example a three-phase configuration, a Y-shaped core structure (Y-type core) in which each I-type core is integrated is disposed in a central region surrounded by the center legs of each phase.

[0013] In this way, placing the Y-shaped core in the central region has the effect of distributing magnetic flux throughout the Y-shaped core. The magnetic flux flowing from the center leg is distributed by the Y-shaped core, and flows through each center leg and each constricted portion of the Y-shaped core to each center leg, while also leaking out to the outer periphery of the core via each outer leg. By adjusting the shape and relative position of these legs and the Y-shaped core, the inductance and leakage inductance can be easily adjusted independently. Furthermore, according to the method for assembling a magnetic coupling reactor of the present invention, a magnetic coupling reactor that exhibits the effects described above can be easily assembled.

[0014] 1 is a plan view illustrating the structure of a magnetic coupling reactor according to a first embodiment of the present invention. FIG. 2 is a schematic diagram (A) and (B) illustrating components constituting the magnetic coupling reactor according to the first embodiment. FIG. 3 is a schematic diagram illustrating the shapes of a magnetic coupling reactor (A) according to a second embodiment and a magnetic coupling reactor (B) according to a third embodiment. FIG. 4 is a schematic diagram (A) illustrating the shape of a magnetic coupling reactor according to a conventional technique, a schematic diagram (B) illustrating components thereof, and a schematic diagram (C) illustrating a conventional technique different from the magnetic coupling reactor shown in (A). FIG. 5 is a perspective view illustrating the structure of a magnetic coupling reactor according to a first embodiment of the present invention (a state fixed with a metal core band, and a state fixed in a metal case, (B)). FIG. 6 is a graph showing the flow of current in a general three-phase magnetic coupling reactor. FIG. 7 is a schematic diagram illustrating the flow of magnetic flux in a magnetic coupling reactor according to an embodiment of the present invention ((A) illustrates the flow of magnetic flux in a first period (T1), and (B) illustrates the flow of magnetic flux in a second period (T2)). 1A and 1B are schematic diagrams illustrating the flow of magnetic flux in a magnetic coupling reactor according to the prior art ((A) shows the flow of magnetic flux in a first period (T1), and (B) shows the flow of magnetic flux in a second period (T2)). Graphs illustrating changes in coil current waveforms with changes in the degree of coupling in a magnetic coupling reactor ((A) is when the degree of coupling is 0, (B) is when the degree of coupling is 0.2, and (C) is when the degree of coupling is 0.4). A flowchart illustrating a method for assembling a magnetic coupling reactor according to an embodiment of the present invention. A diagram illustrating a method for assembling a magnetic coupling reactor according to an embodiment of the present invention (processing for connecting and fixing a coil assembly and an E-core). A diagram illustrating a method for assembling a magnetic coupling reactor according to an embodiment of the present invention (processing for assembling an E-core assembly). A diagram illustrating a method for assembling a magnetic coupling reactor according to an embodiment of the present invention (processing for temporarily fixing an E-core assembly and a Y-core). A diagram illustrating a method for assembling a magnetic coupling reactor according to an embodiment of the present invention (processing for adjusting the position of the Y-core). 1A and 1B are diagrams for explaining a method of assembling the magnetic coupling reactor according to the embodiment of the present invention (full fixing process by filling the product assembly with resin);

[0015]

[0023] Hereinafter, magnetic coupling reactors and methods for assembling the same according to embodiments of the present invention will be described with reference to the drawings. <Magnetic coupling reactor> Fig. 1 is a plan view of a magnetic coupling reactor 100 according to a first embodiment with the bobbin and spacer members removed, Figs. 2A and 2B are plan views showing EI-type cores 115A and 115B having a basic shape for explaining one E-type core 110 that constitutes the magnetic coupling reactor 100 according to this embodiment, and Figs. 3A and 3B are plan views of magnetic coupling reactors 100C and 100D according to second and third embodiments of the present invention with the bobbin and spacer members removed.

[0016] In the structure of the magnetic coupling reactor 100 according to the first embodiment, each phase is configured as an equivalent to a closed magnetic circuit of an EI core, and these are combined into a three-phase configuration to form a hexagonal shape in a plan view, but each I-core is configured as part of a Y-core 160 having an integrated Y-shape. As shown in FIG. 2(A) (where the reference numerals shown in FIG. 1 are used), each EI core has a total of three gaps provided near the tips of one center leg 150c, 151c, and 152c and two outer legs 150a, 150b, 151a, 151b, 152a, and 152b. The gaps near the tips of the center legs mainly change the inductance, and the gaps near the tips of the outer legs mainly change the leakage inductance. Therefore, by adjusting these gap amounts in a balanced manner, the inductance and the leakage inductance can be easily adjusted independently. Furthermore, in such a magnetic coupling reactor 100, the degree of coupling between the coils 170 to 172 is high, and so it has conventionally been difficult to increase the leakage inductance. However, by providing gaps near the tips of the outer legs 150 a, 150 b, 151 a, 151 b, 152 a, and 152 b, it is now possible to increase the leakage inductance.

[0017] As shown in FIG. 1 , each of the E-shaped cores 110, 111, 112 constituting the magnetic coupling reactor 100 of the first embodiment comprises, as main elements, first outer peripheral walls (hereinafter also referred to as base portions) 140, 141, 142 formed in the shape of a flat plate with a predetermined thickness, second outer peripheral walls (hereinafter also referred to as outer leg portions) 150 a, 151 a, 152 a and third outer peripheral walls (hereinafter also referred to as outer leg portions) 150 b, 151 b, 152 b curved inward at a predetermined angle from both ends of the first outer peripheral walls (base portions) 140, 141, 142 so as to form symmetrical shapes with each other, and center legs 150 c, 151 c, 152 c erected on the inner surfaces of the first outer peripheral walls 140, 141, 142, and made of a magnetic member having a generally E-shape in plan view. The E-shaped cores 110, 111, 112 and the adjacent E-shaped cores 110, 111, 112 are arranged in a circumferential direction with the ends of the second outer peripheral walls (outer legs) 150a, 151a, 152a butted against the ends of the third outer peripheral walls (outer legs) 150b, 151b, 152b, to form a columnar outer core 130 having a hexagonal cross section. Each of the middle legs 150c, 151c, 152c extends toward a central portion 135 of the hexagonal cross section, and a Y-shaped core 160 having a Y-shape as a whole is disposed in the space formed in the central portion 135, with a predetermined gap between the ends of the three middle legs 150c, 151c, 152c and the constricted portion 161 facing each other. The Y-shaped core 160 has protrusions (hereinafter also referred to as legs) at every 120 degrees, and these legs extending in three directions of the Y-shaped core 160 are arranged opposite, with a predetermined gap between the ends of the outer legs 150 a, 151 a, 152 a and the ends of the outer legs 150 b, 151 b, 152 b butting against each other. Furthermore, wound coils 170, 171, 172 are fitted into the middle legs 150 c, 151 c, 152 c, respectively.

[0018] The outer legs 150a, 151a, 152a, 150b, 151b, and 152b have large curved ends to facilitate the formation of a gap between them and the Y-shaped core 160. However, they may be formed by bending them inward from the same width as the base portions 140, 141, and 142. The center legs 150c, 151c, and 152c are generally uniform in width all the way to their tips. However, they may have a shape in which the width varies. Furthermore, as shown in FIG. 1, it is easier to adjust the width of the gap between them and the Y-shaped core 160 if their tips are curved, but they may also be flat. Furthermore, when the outer legs 150a, 151a, 152a, 150b, 151b, and 152b butt against each other to form the outer core 130, it is preferable that all of the contact surfaces be flat so that they abut evenly against each other. Although the gap amounts between the tip surfaces of the outer legs 150a, 151a, 152a, 150b, 151b, and 152b and the protruding portion of the Y-core 160, and the gap amounts between the center legs 150c, 151c, and 152c and the constricted portion 161 of the Y-core 160 are ultimately adjusted, they are formed from the component design stage so that the gap amounts are approximately the same for each type of gap. The E-cores 110, 111, and 112 and the Y-core 160 are made of a magnetic material such as a ferrite core. In practice, the coils 170, 171, and 172 are inserted into the center legs 150c, 151c, and 152c via insulating resin bobbins (not shown).

[0019] The combined shape of the E-cores 110, 111, 112 and the Y-core 160 in the magnetic coupling reactor 100 of the first embodiment was created based on the idea of ​​configuring each phase with an EI-core 115A equivalent to a closed magnetic circuit, as shown in FIG. 2A . That is, in this EI-core 115A (combining the E-core 110A and the I-core 160A), between the E-core 110A and the I-core 160A, there is one gap at the tip of the center leg 150Ac and two gaps at the tip of the outer legs 150Aa and 150Ab. In this way, by using the EI-core 115A, it is possible to form a closed magnetic circuit with three gaps for each phase. Adjusting the gap amounts individually allows the inductance and leakage inductance to be adjusted independently, as described above. A coil 170A is fitted into the center leg 150Ac of the E-shaped core 110A. The base 140A, which corresponds to the first outer peripheral walls 140, 141, and 142, functions as a base for the three legs 150Aa, 150Ab, and 150Ac (the same applies to the base 140B in FIG. 2B).

[0020] The EI type core 115B shown in Figure 2(B) has an improved shape from the EI type core 115A shown in Figure 2(A) to facilitate assembly of the three phases. Note that, for components of the EI type core 115B shown in Figure 2(B) that correspond to those of the EI type core 115A shown in Figure 2(A), the reference numerals for the components of the EI type core 115B have been replaced with B instead of A, and a basic description thereof will be omitted. In the EI type core 115B shown in Figure 2(B), the tip of the center leg 150Bc and the tips of both outer legs 150Ba and 150Bb of the E type core 110B are deformed, and the I type core 160B is deformed so as to be curved in a V shape, which facilitates independent adjustment of the gaps G1, G2, and G3. That is, the amount of gap G1 can be adjusted by moving the I-type core 160B in the vertical direction in FIG. 2(B) relative to the E-type core 110B, and the amounts of gaps G2 and G3 can be adjusted by moving the I-type core 160B in the horizontal direction in FIG. 2(B) relative to the E-type core 110B.

[0021] Fig. 3(A) is a plan view showing a magnetic coupling reactor 100C according to a second embodiment of the present invention, which corresponds to a configuration in which three EI-type cores 115B shown in Fig. 2(B) are combined together. Note that, among the components of the magnetic coupling reactor 100C according to the second embodiment shown in Fig. 3(A), those that correspond to the components of the magnetic coupling reactor 100 according to the first embodiment shown in Fig. 1 are designated by adding a C after the reference numeral of the component of the magnetic coupling reactor 100, and a basic description thereof will be omitted. In the magnetic coupling reactor 100C according to the second embodiment, as shown in Fig. 2(B), three I-type cores 160C, 161C, and 162C are bent into a V shape, and are abutted against each other at their straight portions, forming a Y-shape in overall view. Furthermore, the magnetic coupling reactor 100 according to the first embodiment has a hexagonal cross-sectional columnar shape (hexagonal columnar shape) as a whole, whereas the magnetic coupling reactor 100C (and the magnetic coupling reactor 100D) according to the second embodiment (and the following third embodiment) has a hexagonal cross-sectional columnar shape (recessed hexagonal columnar shape) as a whole. Note that the magnetic coupling reactor 100 according to the first embodiment and the magnetic coupling reactors 100C and 100D according to the second and third embodiments have different outer peripheral shapes, but when fixing the outer peripheries of the combined cores with a band or the like, the former is easier to do (see FIG. 5A ).

[0022] 3(B) is a plan view showing a magnetic coupling reactor 100D according to a third embodiment of the present invention, which corresponds to the Y-shaped core 160D formed by integrating the three I-shaped cores 160C, 161C, and 162C shown in FIG. 3(A) described above. Note that, among the components of the magnetic coupling reactor 100D according to the third embodiment shown in FIG. 3(B), those corresponding to the components of the magnetic coupling reactor 100C according to the second embodiment shown in FIG. 3(A) are generally designated by replacing the C in the reference numerals of the components of the magnetic coupling reactor 100C with D, and a basic description thereof will be omitted. In the magnetic coupling reactor 100D according to the third embodiment, the three I-shaped cores 160C, 161C, and 162C of the magnetic coupling reactor 100C according to the second embodiment are integrated to form the Y-shaped core 160D. Therefore, the magnetic coupling reactor 100D has superior characteristics compared to the magnetic coupling reactor 100C according to the second embodiment, and the assembly of the components is facilitated during the manufacturing and assembly process.

[0023] <Description of Prior Art> Here, a magnetic coupling reactor 200 corresponding to the prior art will be described using FIG. 4(A) in comparison with the magnetic coupling reactors 100, 100C, and 100D according to the above embodiments. Also, an E-shaped core 210A relating to the basic configuration of one E-shaped core 200 constituting the magnetic coupling reactor 200 will be described using FIG. 4(B), and a magnetic coupling reactor 200B according to a prior art different from the magnetic coupling reactor 200 will be described using FIG. 4(C). Note that FIG. 4(A) corresponds to FIG. 1 so as to clearly show the differences from the first embodiment, and FIG. 4(C) corresponds to FIG. 3(B) so as to clearly show the differences from the third embodiment.

[0024] Here, among the components of the magnetic coupling reactor 200 corresponding to the conventional technology shown in FIG. 4A , those corresponding to the components of the magnetic coupling reactor 100 according to the first embodiment shown in FIG. 1 are designated by the same reference numerals as the components of the magnetic coupling reactor 100, but with a difference of 100, and a basic description thereof will be omitted. As shown in FIG. 4A , the magnetic coupling reactor 200 corresponding to the conventional technology does not include a Y-shaped core 160 between the center legs 250 c, 251 c, and 252 c in the central region of the magnetic coupling reactor 200, unlike the magnetic coupling reactor 100 according to the first embodiment. Therefore, the gap (the gap within the dotted circle g) that exists in each closed magnetic circuit is only one location, between the opposing center legs 250 c, 251 c, and 252 c. Adjusting the spacing of this gap affects both the inductance and the leakage inductance in a similar manner, making it difficult to adjust each independently. Furthermore, in such a three-phase magnetic coupling reactor 200, the degree of coupling between the coils 270 to 272 is high, making it difficult to increase the leakage inductance.

[0025] Furthermore, for each component of the E-type core 210A according to the conventional technology shown in FIG. 4(B) that corresponds to each component of the E-type core 210 of the magnetic coupling reactor 200 according to the conventional technology shown in FIG. 4(A), the reference numeral of each component of the E-type core 210 in FIG. 4(A) is marked with an A, and a basic description thereof will be omitted.

[0026] Furthermore, for each component of magnetic coupling reactor 200B corresponding to the conventional technology shown in Fig. 4(C), those that correspond to those of magnetic coupling reactor 200 according to the conventional technology shown in Fig. 4(A) are denoted by a reference numeral with a B added after the reference numeral of the corresponding component of magnetic coupling reactor 200 shown in Fig. 4(A), and a basic description thereof will be omitted. Similarly to magnetic coupling reactor 200 corresponding to the conventional technology shown in Fig. 4(A), magnetic coupling reactor 200B corresponding to the conventional technology shown in Fig. 4(C) does not include Y-shaped core 160D between center legs 250Bc, 251Bc, and 252Bc in the central region of magnetic coupling reactor 200B, as in magnetic coupling reactor 100D according to embodiment 3. Therefore, the gap that exists in each closed magnetic circuit (the gap within the dotted circle g') is only one between the opposing center legs 250Bc, 251Bc, and 252Bc. Adjusting the spacing of this gap affects both the inductance and the leakage inductance, making it difficult to adjust them independently. Furthermore, in this three-phase magnetic coupling reactor 200B, the degree of coupling between the coils 270B to 272B is high, making it difficult to increase the leakage inductance. The magnetic coupling reactor 200 corresponding to the prior art shown in FIG. 4A is shaped like a column with a hexagonal cross section (hexagonal prism) as a whole, whereas the magnetic coupling reactor 200B according to the prior art shown in FIG. 4C differs in that it is shaped like a column with a concave hexagonal cross section (concave hexagonal prism) as a whole.

[0027] As described above, the structure of the magnetic coupling reactor 200 according to the prior art has a problem with balancing the inductance values ​​(L values) of the three E-shaped cores 210, 211, and 212. The variations in inductance values ​​(L values) of the three coils 270, 271, and 272 are due to various factors (variations in the magnetic characteristics (permeability) of the cores, variations in the electrical characteristics of the coils, mechanical dimensional errors of each component, errors in the positional relationship between the cores, etc.), and when these three E-shaped cores 210, 211, and 212 are assembled, subtle differences in the fit between the cores change the gap position and effective permeability between the cores, which causes fluctuations in the characteristics of the three coils 270, 271, and 272. Therefore, in the past, the characteristics of the three coils 270, 271, and 272 varied depending on the cores and coils to be combined and the finished state of assembly, and there was no way to control this. However, this variation has raised concerns that, for example, only specific coils 270, 271, and 272 with high inductance may saturate first, which has been a major problem (the same applies to magnetic coupling reactor 200B shown in FIG. 4C). Therefore, it is highly significant that the magnetic coupling reactor 100 according to this embodiment has been devised, which makes it possible to roughly match the inductance values ​​of the three coils 270, 271, and 272. In particular, the practical effect of being able to match the inductance values ​​during the manufacturing process is significant.

[0028] <Fixing Process of Magnetic Coupling Reactor According to Embodiment> In the magnetic coupling reactor 100E according to this embodiment, as shown in FIG. 5A , three E-shaped cores 110E, 111E, and 112E, a Y-shaped core 160E, and three coils 170E, 171E, and 172E are combined (this configuration is also referred to as the main body of the magnetic coupling reactor), and the entire outer periphery is fastened and fixed with a metal core band 120E. This prevents deviations in magnetic characteristics and facilitates product assembly work in the manufacturing and assembly process. Note that, among the components of the magnetic coupling reactor 100E shown in FIG. 5A (and FIG. 5B ), those corresponding to the components of the magnetic coupling reactor 100 according to the first embodiment shown in FIG. 1 are designated by the letter E after the reference numeral of the component of the magnetic coupling reactor 100 in FIG. 1 , and a basic description thereof will be omitted. Note that the reference numerals of the members shown in FIG. 5A (and FIG. 5B) are partially overlapped with the reference numerals of the members shown in FIGS. 10A to 10E, which will be described later.

[0029] FIG. 5(B) shows a state in which the magnetic coupling reactor 100E, which has been fastened and fixed with a metal core band 120E as shown in FIG. 5(A), is housed in a metal case 125E, and the inside of the metal case 125E is filled with resin 131E, which has good heat dissipation properties, thereby finally fixing the magnetic coupling reactor 100E.

[0030] <Flow of Magnetic Flux> A three-phase AC current as shown in FIG. 6 flows through the coils 170, 171, and 172 of the magnetic coupling reactor 100 according to the first embodiment. The phases of the first, second, and third phase currents are shifted by ⅓ of a cycle. The horizontal axis of the graph in FIG. 6 represents time, and the vertical axis represents current value (A). When such currents flow through the coils 170, 171, and 172, the magnetic flux generated in the cores (E-shaped cores 110, 111, and 112 and the Y-shaped core 160) flows as shown in FIGS. 7A and 7B in the magnetic coupling reactor 100 according to the first embodiment, whereas the magnetic flux flows as shown in FIGS. 8A and 8B in the prior art. For ease of explanation, the magnetic coupling reactors 100 and 200 shown in FIGS. 7(A) and 7(B) and FIGS. 8(A) and 8(B) are shown rotated 180 degrees from the magnetic coupling reactor 100 shown in FIG. 1 . Components shown in FIGS. 7(A) and 7(B) that correspond to components shown in FIG. 1 may be indicated by adding an A after the reference numeral of the component shown in FIG. 1 . Components shown in FIGS. 8(A) and 8(B) that correspond to components shown in FIGS. 7(A) and 7(B) are indicated by adding a reference numeral that is 100 larger than the reference numeral of the component shown in FIGS. 7(A) and 7(B). The timing at which the magnetic flux shown in FIGS. 7(A) and 8(A) is generated corresponds to a period, such as period 1 (T1) in FIG. 6, in which only one current value graph rises to the right and the other two current value graphs fall to the right. On the other hand, the period in which magnetic flux as shown in Figures 7(B) and 8(B) is generated corresponds to a period in which the graphs of two current values ​​rise to the right and the graph of the remaining current value falls to the right, such as period 2 (T2) in Figure 6.

[0031] 7, when the Y-core 160 is disposed between the center legs 150c, 151c, and 152c, the magnetic flux flow m from a given center leg 150c, 151c, or 152c is distributed by the Y-core 160 due to the magnetic flux distribution effect of the Y-core 160. A portion of the distributed magnetic flux flow m leaks to the outer periphery of the core through gaps between the leg tips 160p, 160q, and 160r of the Y-core 160 and the tips of the outer legs 150Aa, 150Ab, 151Aa, 151Ab, 152Aa, and 152Ab. This prevents the magnetic flux from interlinking with other coils, reducing the degree of coupling between the coils and increasing the leakage inductance. By adjusting the shapes of the outer legs 150Aa, 150Ab, 151Aa, 151Ab, 152Aa, and 152Ab and the shape of the Y-shaped core 160, the amount of gap between the Y-shaped core 160 and the outer legs 150Aa, 150Ab, 151Aa, 151Ab, 152Aa, and 152Ab can be changed, and the leakage inductance (degree of coupling between the coils) can be freely adjusted.

[0032] In contrast, in the magnetic coupling reactor 200 according to the prior art shown in FIG. 4A, as shown in FIGS. 8A and 8B, there is only one gap between each of the center legs 250c, 251c, and 252c, and part of the magnetic flux flow m does not leak from the outer legs 250Aa and 250Ab to the outer periphery of the core, and the magnetic flux interlinks with other coils. Therefore, the degree of coupling between the coils cannot be reduced, and it is difficult to significantly increase the leakage inductance.

[0033] As shown in Figures 7(A) and (B), the magnetic flux within the Y-shaped core 160 is mixed up, and although some of the fluxes cancel each other out, the magnetic flux does not become zero in the central region, which is different from the prior art.

[0034] Figure 9 shows how the coil current waveform changes depending on the degree of coupling ((A) is when the degree of coupling is 0, (B) is when the degree of coupling is 0.2, and (C) is when the degree of coupling is 0.4). When the degree of coupling is high, the DC superposition is better than when there is only one coil. However, the influence between the coils becomes more pronounced, resulting in greater core loss. On the other hand, when the degree of coupling is low, the DC superposition is inferior to when there is only one coil (performance is the same as when there is only one coil at a degree of coupling of 0). However, core loss is reduced. Furthermore, when the degree of coupling becomes 1, the height of the triangular waves appearing on both sides of the central peak at a degree of coupling of 0.4 in Figure 9(C) becomes equal to the height of the central peak, resulting in a triangular wave with three times the drive frequency of when there is only one coil. It is important to determine the degree of coupling based on the intended use and design concept.

[0035] <Method of Assembling a Magnetic Coupling Reactor> A method of assembling a magnetic coupling reactor according to an embodiment of the present invention will be described below with reference to Fig. 10 and Figs. 10A to 10E. Fig. 10 is a flowchart that schematically illustrates the flow of a method of assembling a magnetic coupling reactor according to this embodiment, and Figs. 10A to 10E are drawings that explain each of the processes in step 1 (S1) to step 5 (S5) shown in Fig. 10. As shown in the flowchart of Fig. 10, the method of assembling a magnetic coupling reactor according to this embodiment begins with preprocessing for arranging each component (for example, winding a wire around an insulating bobbin to create coil sections (coil assemblies) 170E, 171E, and 172E) (S1: see Fig. 10A (A)). Next, the coil sections (coil assemblies) 170E, 171E, 172E are fitted into the middle leg sections 150Ec, 151Ec, 152Ec of the corresponding E-shaped cores 110E, 111E, 112E, and a process for connecting and fixing the coil sections (coil assemblies) 170E, 171E, 172E to the E-shaped cores 110E, 111E, 112E is performed (S2: see FIG. 10A(c)). Next, an assembly process for the three E-shaped core assemblies 110E', 111E', 112E' formed by fitting the coil sections (coil assemblies) 170E, 171E, 172E into the middle leg sections 150Ec, 151Ec, 152Ec is performed (S3: see FIG. 10B).

[0036] Next, when the three E-core assemblies 110E', 111E', and 112E' are assembled, the Y-core 160E is inserted into the space formed in the central region thereof, and portions of the E-cores 110E, 111E, and 112E are temporarily fixed (not rigidly fixed) to portions of the Y-core 160E with adhesive, thereby starting the temporary fixing process of the E-core assemblies 110E', 111E', and 112E' and the Y-core 160E (S4: see Figure 10C).

[0037] Next, with the E-core assemblies 110E', 111E', and 112E' and the Y-core 160E temporarily fixed, the position of the Y-core 160E is finely adjusted in the space formed in the central region while measuring the inductance value (L value) of each coil portion (coil assembly) 170E, 171E, and 172E (S4: see FIG. 10D). After this, the magnetic coupling reactor main body 100Ea adjusted in step 4 (S4) is housed in a metal case 125E, and the metal case 125E is filled with resin 131E, thereby performing a final fixing process for the product assembly 100Eb (S5: see FIG. 10E).

[0038] Each of the above steps (S1 to S5) will be described in detail below with reference to FIGS. 10A to 10E . <Method of Assembling a Magnetic Coupling Reactor> First, step 1 (S1) will be described. As described above, step 1 involves pre-processing for component assembly. This pre-processing may vary depending on the intended use of the product, but may include, as shown in FIG. 10A (A), forming a coil section (coil assembly) 170E by winding a predetermined rectangular wire vertically (edgewise) around a wire-winding section between two frames 176E of a hollow rectangular bobbin 175E made of insulating resin. This pre-processing is performed for each of the three coil sections (coil assemblies) 170E, 171E, and 172E corresponding to each of the E-shaped cores 110E, 111E, and 112E.

[0039] Next, the above step 2 (S2) will be described. As described above, step 2 relates to the process of connecting and fixing the coil parts (coil assemblies) 170E, 171E, and 172E to the E-shaped cores 110E, 111E, and 112E. 10A, the hollow portion 177E of the bobbin 175E constituting the coil portion (coil assembly) 170E has a rectangular cross section. After being inserted into the corresponding center leg 150Ec of the E-shaped core 110E without significant rattle, the two are fixed by adhesive bonding. Furthermore, when the coil portion (coil assembly) 170E is inserted into the center leg 150Ec, the side edge of the frame 176E of the coil portion (coil assembly) 170E of each bobbin 175E is sandwiched between the outer leg 150Ea and the outer leg 150Eb. This allows the coil portion (coil assembly) 170E and the center leg 150Ec to be fixed to each other without rattle in the three directions, i.e., vertical, horizontal, and height, as shown in FIG. 10A(C).

[0040] Next, step 3 (S3) will be described. As described above, step 3 relates to the assembly process of the three E-core assemblies 110E', 111E', and 112E'. The assembly process of the E-core assemblies 110E', 111E', and 112E' involves combining the three E-core assemblies 110E', 111E', and 112E' to form a columnar shape with a hexagonal cross section as a whole, as shown in FIG. 10B . At this time, the tips of the center leg portions 150Ec, 151Ec, and 152Ec (152Ec is not shown), into which the coil portions (coil assemblies) 170E, 171E, and 172E are fitted, are positioned so that they face the central region of the overall shape. The three E-core assemblies 110E', 111E', and 112E' are assembled to form a column with a hexagonal cross section as a whole, and then fixed by fastening the outer peripheral side surfaces with multiple metal core bands 120E, thereby preventing misalignment between the three E-core assemblies 110E', 111E', and 112E'.

[0041] Next, step 4 (S4) will be described. As described above, the temporary fixing process in step 4 relates to the temporary fixing process of the E-core assemblies 110E', 111E', and 112E' and the Y-core 160E. The Y-core 160E (see FIG. 10C(A)) is inserted into the space formed in the central region of the combination of the three E-core assemblies 110E', 111E', and 112E', and parts of the E-cores 110E, 111E, and 112E are bonded to parts of the Y-core 160E, thereby temporarily fixing the E-core assemblies 110E', 111E', and 112E' and the Y-core 160E (S4: see FIG. 10C). 10C(B), the Y-shaped core 160E is oriented such that the constricted portion 161E faces the tips of the three middle legs 150Ec, 151Ec, and 152Ec (152Ec is not shown) with a predetermined gap between them. Furthermore, the protruding portions 162E of the Y-shaped core 160E face the vicinity of the joint between the outer leg 150Ea of the E-shaped core 110E and the outer leg 151Eb of the E-shaped core 111E, the vicinity of the joint between the outer leg 151Ea of the E-shaped core 111E and the outer leg 152Eb of the E-shaped core 112E, and the vicinity of the joint between the outer leg 152Ea of the E-shaped core 112E and the outer leg 150Eb of the E-shaped core 110E with a predetermined gap between them.

[0042] 10C (C), adhesives 180E, 181E, and 182E are applied to the gaps between the protrusions 162E of the Y-core 160E and the joints of the outer legs 150Ea and 151Eb, thereby temporarily fixing the E-core assemblies 110E', 111E', and 112E' to the Y-core 160E (in this embodiment, temporary fixing is considered to have started once the adhesive has been applied). For example, a UV-curable adhesive is applied as the adhesive 180E, 181E, and 182E to secure the gaps to an extent that allows for adjustment of the gap. After the gap adjustment is complete, a UV-curable adhesive is irradiated with ultraviolet light using an ultraviolet lamp to firmly fix the adhesive. The position where adhesive is applied to temporarily fix the E-type core assemblies 110E', 111E', and 112E' to the Y-type core 160E is not limited to the position shown in Figure 10C (C), and adhesive may be applied to other positions, for example, the gap position between the narrowed portion 161E of the Y-type core 160E and the tip end of each middle leg portion 150Ec, 151Ec, and 152Ec, thereby temporarily fixing the E-type core assemblies 110E', 111E', and 112E' to the Y-type core 160E.

[0043] Next, the position adjustment process performed in step 4 (S4) along with the temporary fixation process will be described. As mentioned above, the position adjustment process in step 4 relates to adjusting the position of the Y-shaped core 160E. For simplicity, an example of adjusting the gap between the tip of the center leg 150Ec, 151Ec, or 152Ec and the constricted portion 161E of the Y-shaped core 160E will be described. However, the same procedure is used to adjust the gap between the tip of the outer leg 150Ea, 150Eb, 151Ea, 151Eb, 152Ea, or 152Eb and the protruding portion 162E of the Y-shaped core 160E. It is important to alternately adjust the two types of gaps multiple times to achieve optimal settings. In a state where the E-core assemblies 110E', 111E', and 112E' and the Y-core 160E are temporarily fixed (see FIG. 10C(C)), the inductance values ​​(L values) of the coil portions (coil assemblies) 170E, 171E, and 172E are measured, and the position of the Y-core 160E is finely adjusted in the space formed in the central region to perform a position adjustment process for the Y-core 160E (S4: see FIG. 10D). The inductance values ​​(L values) of the E-core assemblies 110E', 111E', and 112E' are individually affected by various factors, such as dimensional errors of the cores, errors in the magnetic permeability of the core materials, and misalignment of the cores, which cause errors to occur relative to each other.

[0044] Because an error occurs between the inductance values ​​(L values) of the E-core assemblies 110E', 111E', and 112E', even if the Y-core 160E is placed at the center of the space in the central region, the measured inductance values ​​(L values) of the three coil sections (coil assemblies) 170E, 171E, and 172E (outputs from the inductance meters (LCR meters) 190E, 191E, and 192E) will not match. In a magnetic coupling reactor, the more balanced the inductance values ​​(L values) are, the higher the upper limit of the allowable current value can be. Therefore, it is necessary to improve the imbalance of the inductance values ​​(L values).

[0045] Therefore, in this embodiment, the gap dimension with the Y-shaped core 160E is changed depending on the measurement error (output error from each inductance meter 190E, 191E, 192E) of the inductance value (L value) of each coil section (coil assembly) 170E, 171E, 172E, thereby improving the characteristic difference between the coils for each inductance value (L value). That is, when the measured inductance value (L value) (output from each inductance meter 190E, 191E, 192E) is high, the gap is widened to decrease the magnetic permeability and adjust the inductance value (L value). Conversely, when the measured inductance value (L value) (output from each inductance meter 190E, 191E, 192E) is low, the gap is narrowed to increase the magnetic permeability and adjust the inductance value (L value).

[0046] Furthermore, during mass production of magnetic coupling reactors, it is preferable to mount the Y-shaped core 160E on an electrically driven XYθ table, directly connect this XYθ table to an inductance value (L value) measurement system, and automatically control the gap adjustment. In other words, in such a system, the following steps <1> to <4> are performed to adjust the position of the Y-shaped core 160E to the optimal position. <1> To calculate the inductance values ​​(L values) of each coil section (coil assembly) 170E, 171E, and 172E, the inductance values ​​(L values) measured by each inductance meter 190E, 191E, and 192E are sent to a sequencer or the like. <2> Next, the sequencer or the like calculates each inductance value (L value) to determine the direction and amount of movement of the Y-shaped core 160E. <3> Next, the position of the XYθ table is controlled to adjust the gap amount for the Y-shaped core 160E mounted on the XYθ table. <4> By repeating the series of processes described above, <1> measurement → <2> judgment → <3> adjustment of gap amount, in a loop several times, the position of the Y-shaped core 160E can be adjusted to the optimal position.

[0047] Next, step 5 (S5) will be described. As described above, step 5 relates to the main fixing process of filling the product assembly 100Eb with resin. A metal case 125E with good conductivity is prepared (see FIG. 10E(A)). The magnetic coupling reactor main body 100Ea, which has been adjusted in step 5 (S5), is placed inside the metal case 125E so that there is a slight gap between the main body 100Ea and the inner wall of the metal case 125E (see FIG. 10E(B)). After that, resin such as epoxy resin or silicone resin is filled into the metal case 125E, and the main body 100Ea is finally adhesively fixed to the product assembly 100Eb by filling the resin, thereby completing the main fixing process (see FIG. 10E(C)).

[0048] The magnetic coupling reactor and its assembly method of the present invention are not limited to those of the above embodiment and can be modified in various other ways. For example, in the above embodiment, the magnetic coupling reactor 100 is formed by combining three E-shaped cores 110, 111, and 112, but the number of E-shaped cores to be combined is not limited to this, and it is also possible to form a magnetic coupling reactor using four or more E-shaped cores. Furthermore, it is preferable that the Y-shaped core in the above embodiment be a multi-leg core having protrusions in the same number as the number of E-shaped cores to be combined.

[0049] Furthermore, when manufacturing the E-cores 110, 111, and 112 and the Y-core 160, a laminated core formed by stacking plate-shaped magnetic materials may be used, or block-shaped cores formed by molding magnetic powder and then heat-treating and solidifying them may be bonded together. The shapes of the outer legs 150a, 150b, 151a, 151b, 152a, and 152b of the E-cores 110, 111, and 112, the middle legs 150c, 151c, and 152c, and the Y-core 160 are not limited to those described in the embodiments, and various shapes may be used. In particular, the core shapes of the portions that form the gap (e.g., the shape of the tip ends of the legs of the E-cores 110, 111, and 112 and the shape of the constricted portion 161 of the Y-core 160) are preferably shapes that facilitate adjustment of the gap amount. In the above embodiment, flat wire is used as the wire material for the coils 170, 171, and 172, but the wire material for the coils 170, 171, and 172 is not limited to this and other wire materials may be used, such as round wire or square wire. Note that the coils 170 to 172 may be wound after bobbins are inserted into the middle legs 150c to 152c.

[0050] In the assembly method according to the above embodiment, the E-core assemblies 110E', 111E', and 112E' are temporarily fixed before the magnetic coupling reactor main body 100Ea is housed in the metal case 125E, but the E-core assemblies 110E', 111E', and 112E' may be temporarily fixed after the magnetic coupling reactor main body 100Ea is housed in the metal case 125E. In the above embodiment, the temporary fixing process of the E-core assemblies 110E', 111E', and 112E' to the Y-core 160E is performed before and after the process of moving the position of the Y-core 160E (position adjustment process) to adjust the gap amount. However, the temporary fixing process and the position adjustment process in step 4 (S4) may be performed simultaneously, or one process may be performed after the other process. That is, for example, after completing a process of moving the position of the Y-core to adjust the gap amount (position adjustment process), a temporary fixing process may be performed between the E-cores 110E', 111E', and 112E' and the Y-core 160E. Also, for example, if the degree of fixation in the temporary fixing process is weak and the position of the Y-core 160E can be moved by a small amount after the temporary fixing process is completed, the position adjustment process may be performed after the temporary fixing process is completed.

[0051] 100, 100C, 100D, 100E, 200, 200B Magnetic coupling reactor 100Ea Main body of magnetic coupling reactor 110, 111, 112, 110E, 111E, 112E, 210, 211, 212, 210A, 211A, 212A E-type core 110E', 111E', 112E' E-type core ASSY 115A, 115B EI-type core 120E Metal core band 125E Metal case 130 Outer circumferential core 131E Resin 135 Central portion 140 First outer circumferential wall 150a Second outer circumferential wall 150b Third outer circumferential wall 150Aa, 150Ab, 151Aa, 151Ab, 152Aa, 152Ab, 150Ba, 150Bb, 151Ba, 151Bb, 152Ba, 152Bb, 150Ea, 150Eb, 151Ea, 151Eb, 152Ea, 152Eb External leg 150c, 151c, 152c, 150Ac, 151Ac, 152Ac, 150Bc, 151Bc, 152Bc, 150Ec, 151Ec, 152Ec, 250c, 251c, 252c, 250Bc, 251Bc, 252Bc Middle leg 160, 160D, 160E Y type core 160A, 160B, 160C, 161C, 162C I-type core 160p, 160q, 160r Tip of protruding part 161, 161E Narrowed part 162E Protruding part 170, 171, 172, 170A, 171A, 172A, 170E, 171E, 172E, 270, 271, 272, 270A, 270B, 271B, 272B Coil 170E, 171E, 172E Coil part (coil assembly) 175E Bobbin 176E Frame 177E Hollow part 180E, 181E, 182E Adhesive 190E, 191E, 192E Inductance meter (LCR meter) G1, G2, G3 Gap m magnetic flux flow

Claims

1. A magnetic coupling reactor comprising: a first magnetic outer peripheral wall formed in a plate shape of a predetermined thickness, a second magnetic outer peripheral wall and a third magnetic outer peripheral wall curved at a predetermined angle from both ends of the first magnetic outer peripheral wall so as to form a symmetrical shape with respect to each other, and a magnetic center leg erected on the inner surface of the first magnetic outer peripheral wall, N E-shaped magnetic members having a generally E-shape in plan view are arranged in the circumferential direction with the ends of the second magnetic outer peripheral wall and the ends of the third magnetic outer peripheral wall of adjacent E-shaped magnetic members butting against each other, a 2N-sided polygonal cross section of an outer core, a multi-leg core having the N legs radially arranged, the N legs being arranged in a space formed in the central portion of the outer core with each of the magnetic center legs extending toward the central portion, and the N legs being arranged opposite each other with a predetermined gap between the ends of the N magnetic center legs, and a coil wound around each of the magnetic center legs (where N is a natural number of 3 or more).

2. A magnetic coupling reactor comprising: an outer core having a hexagonal cross section formed by arranging three E-shaped cores having a roughly E-shape in a plan view in the circumferential direction, the E-shaped cores including a first magnetic outer peripheral wall formed in a flat plate with a predetermined thickness, a second magnetic outer peripheral wall and a third magnetic outer peripheral wall curved at a predetermined angle from both ends of the first magnetic outer peripheral wall so as to form symmetrical shapes with respect to each other, and a magnetic center leg erected on the inner surface of the first magnetic outer peripheral wall, with the end of the second magnetic outer peripheral wall and the end of the third magnetic outer peripheral wall of adjacent E-shaped cores butting against each other; a Y-shaped core having a Y shape in overall view, in which constricted portions are arranged opposite each other with a predetermined gap between them and the tips of the three magnetic center legs in a space formed in the central portion with each of the magnetic center legs extending toward the central portion of the outer core; and a coil wound around each of the magnetic center legs.

3. A magnetic coupling reactor according to claim 2, wherein the second outer magnetic wall and the third outer magnetic wall are arranged so as to protrude inward.

4. The magnetic coupling reactor according to claim 2, wherein the Y-shaped core is formed by adjacently connecting a plurality of core members to form a Y shape.

5. A magnetic coupling reactor according to claim 2, wherein the outer core has a cross-sectional shape of a concave hexagon.

6. A magnetic coupling reactor as described in any one of claims 2 to 5, characterized in that the legs extending in three directions of the Y-shaped core are arranged facing each other with a predetermined gap between the portion where the end of the second magnetic outer wall and the end of the third magnetic outer wall are butted together.

7. Preparing three E-shaped cores having a generally E-shape when viewed from above, the E-shaped cores having a first magnetic outer wall formed in a flat plate shape with a predetermined thickness, a second magnetic outer wall and a third magnetic outer wall curved at a predetermined angle from both ends of the first magnetic outer wall so as to form symmetrical shapes with respect to each other, and a magnetic center leg erected on the inner surface of the first magnetic outer wall; connecting and fixing a wound coil to each of the magnetic center legs of the three E-shaped cores; assembling the E-shaped cores by butting the ends of the second magnetic outer wall and the third magnetic outer wall of adjacent E-shaped cores together and arranging them in the circumferential direction to assemble an outer core having a hexagonal cross section; and disposing a Y-shaped core having a Y-shape when viewed overall in a space formed in the central portion with each of the magnetic center legs extending toward the central portion of the outer core, so that the narrowed portions are arranged opposite each other with a predetermined gap between the tips of the three magnetic center legs; a position of the Y-core is moved within the space and the E-core and the Y-core are temporarily fixed in place in order to adjust the amount of the gap so as to reduce a characteristic difference between the three coils; a magnetic coupling reactor body including the E-core, the coils, and the Y-core is housed in a specified case, and the case is filled with resin to perform final fixing.

8. A method for assembling a magnetic coupling reactor as described in claim 7, characterized in that the Y-shaped core is positioned facing the portion where the end of the second magnetic outer wall and the end of the third magnetic outer wall are butted together, with a predetermined gap between them.

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