Magnetic coupling reactor device

Abstract

A magnetic coupling reactor device capable of reducing magnetic leakage and improving DC superposition characteristics by increasing the degree of coupling compared to the prior art. A pair of iron-based E-shaped cores (101A, 101B) are arranged with their center-leg cores butted against each other, and coils (103A, 103B) are respectively assembled in a wound state on the center-leg cores (101A3, 101B3). Furthermore, when the cross-sectional area of the center-leg cores (101A3, 101B3) perpendicular to the extending direction of the center-leg cores (101A3, 101B3) is Si, and the cross-sectional area of the outer-leg cores (101A1, 101B1, 101A2, 101B2) perpendicular to the extending direction of the outer-leg cores is So, the following conditional expression (1) is established: 1.0≤Si / So≤5.0(1).

Description

Technical Field

[0001] The present invention relates to a magnetic coupling type reactor device mounted on, for example, an electric vehicle or a hybrid vehicle. Specifically, the present invention relates to a magnetic coupling type reactor device in which a plurality of coil portions are passed through a portion of a core constituting a magnetic circuit, and the coil portions are magnetically coupled. Background Art

[0002] A known in-vehicle magnetic coupling reactor device comprises a pair of U-shaped cores, each with its legs butted together at the distal ends, forming a ring-shaped core. Coils are wound around each of the U legs, resulting in a total of four coils. Furthermore, in this magnetic coupling reactor, magnetic fluxes in the two coils are generated in mutually canceling directions, thereby minimizing magnetic saturation of the core. Furthermore, pulsation is suppressed by utilizing mutual inductance, thereby achieving miniaturization and improved efficiency (see Patent Document 1 below).

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent No. 6106646 Summary of the Invention

[0005] Problems to be solved by the invention

[0006] However, magnetically coupled reactors typically use a pair of U-shaped cores, as described above. This makes it difficult to improve the coupling coefficient, a key parameter for reducing ripple, and magnetic leakage tends to increase. Furthermore, low coupling deteriorates the DC superposition characteristics, which is also problematic.

[0007] 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 device capable of reducing magnetic flux leakage and improving DC superposition characteristics by increasing the degree of coupling compared to the conventional technology.

[0008] Solutions to Problems

[0009] In order to solve the above-mentioned problems, the magnetic coupling reactor device of the present invention is characterized in that:

[0010] The magnetic coupling reactor device includes at least one pair of multi-leg core members, each of which is made of an iron-based material and includes a base core portion and three or more leg core portions protruding in the same direction from the base core portion.

[0011] The at least one pair of multi-leg core components are arranged in a manner that the corresponding leg core parts are butted against each other, and at least one corresponding leg core part for coil winding is selected from the corresponding leg core parts, excluding the two outer leg core parts, and the inner leg core parts, and the coil parts are respectively assembled in a wound state at the positions of the butt joint parts of the selected corresponding leg core parts for coil winding, sandwiching the inner leg core parts, thereby forming a magnetic coupling type structure.

[0012] When the cross-sectional area of the leg core portion for coil winding, which is perpendicular to the extension direction of the leg core portion for coil winding, is set as Si, and the cross-sectional area of each of the two outer leg core portions, which is perpendicular to the extension direction of the leg core portion for coil winding, is set as So, the following conditional expression (1) is satisfied:

[0013] 1.0≤Si / So≤5.0 (1).

[0014] Here, “each cross-sectional area of the two outer leg core parts” needs to satisfy the above-mentioned formula (1) for each of the two outer leg core parts when the cross-sectional areas of the outer leg core parts are different from each other.

[0015] Preferably, the range of the conditional expression (1) is limited to the range of the following conditional expression (2),

[0016] 1.5≤Si / So43.5 (2).

[0017] In addition, it is further preferred that the range of the conditional expression (1) is limited to the range of the following conditional expression (3),

[0018] 1.5≤Si / So≤3.0 (3).

[0019] Preferably, the multi-leg core member is composed of an E-shaped core member.

[0020] The magnetic coupling reactor device is formed by assembling one coil portion in a wound state on each of the coil winding leg core portions, that is, the middle leg core portions, of the E-shaped core member.

[0021] Furthermore, it is preferable that the middle leg core portion is offset upward from the both outer leg core portions by at least the width of the coil portion.

[0022] Preferably, the input ends of the coil parts respectively assembled to the corresponding coil winding leg core parts of the pair of multi-leg core members are arranged on one side relative to the axis of the multi-leg core member, and the winding directions of the coil parts are opposite to each other.

[0023] Preferably, the magnetically coupled inductor device is constructed so that the respective input ends and output ends of the coil parts formed by the corresponding coil winding leg core parts of the pair of multi-leg core components are led out to the upper end surface of the outer leg core part on one side, and the height of the outer leg core part on one side is set to be lower than the height of the outer leg core part on the other side by a dimension corresponding to the width of the coil part.

[0024] Furthermore, it is preferable that each corner of the E-shaped core member is chamfered so as to extend in the thickness direction of the E-shaped core member.

[0025] Preferably, the cross-sectional area of the outer leg core portion on one side in a direction perpendicular to the axis is formed to be equal to the cross-sectional area of the outer leg core portion on the other side in a direction perpendicular to the axis, and in these two cross-sections, the cross-sectional area of the one side is formed to be lower in height and wider in width than the cross-sectional area of the other side.

[0026] Moreover, preferably, the magnetically coupled inductor device is formed by installing a resin material having a thickness equivalent to the difference in height between the outer leg core portion on one side and the outer leg core portion on the other side on the upper surface of the outer leg core portion on one side to the respective input ends and output ends where the coil portion is not configured.

[0027] In addition, it is preferred that one or more air gaps are provided in the middle leg core portion.

[0028] Furthermore, it is preferred that one or more air gaps are provided in at least one of the two outer leg core portions instead of or in addition to the middle leg core portion.

[0029] Effects of the Invention

[0030] According to the magnetic coupling type inductor device of the present invention, the iron-based multi-leg core components are connected to form a core portion, and coil portions are respectively arranged on the opposite inner legs of the multi-leg core components. Therefore, compared with the magnetic coupling type inductor device of the aforementioned patent document 1, the distance between the coils arranged along the axial direction of the coil portion can be shortened, the coupling degree can be easily improved, and the proportion of magnetic flux leakage can be reduced.

[0031] Furthermore, by setting the ratio of the cross-sectional area of the coil winding leg core portion to the cross-sectional area of the outer leg core portion to between 1.0 and 5.0, the self-inductance can be set to a large value, and the DC superposition characteristic can be maintained at a desired value.

[0032] Furthermore, since the coil portions are respectively arranged in at least a pair of opposing inner leg core portions of the multi-leg core member, they are surrounded by the magnetic path, and magnetic flux leakage to the outside can be significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a perspective view showing an embodiment of the present invention, in which a magnetic coupling reactor device is formed by winding a coil portion only around a center leg portion of an E-shaped core.

[0034] Figure 2 Yes Figure 1 A perspective view of only the core portion of the magnetic coupling reactor device shown.

[0035] Figure 3 It is a perspective view showing the appearance of the magnetic coupling reactor device according to the present invention.

[0036] Figure 4 Yes Figure 1 A perspective view of the cross-sectional shape of a core of the magnetic coupling reactor device shown.

[0037] Figure 5 This is a graph plotting changes in inductance versus the value of the cross-sectional area of the middle leg core / the cross-sectional area of the outer leg core.

[0038] Figure 6 It is a cross-sectional view showing a state where the middle leg core is offset relative to the outer leg core.

[0039] Figure 7 It is a three-dimensional diagram showing a situation where the heights of the core parts of the two outer legs are different from each other.

[0040] Figure 8 It is a cross-sectional view showing the difference in height and width of the core parts of the two outer legs.

[0041] Figure 9 This is a cross-sectional view showing a state where a resin member is disposed at a predetermined position in order to suppress the influence of the difference in height between the core portions of the two outer legs. DETAILED DESCRIPTION

[0042] <Implementation Method>

[0043] The following, appropriate use Figure 1 , and other figures illustrate a magnetically coupled reactor device according to an embodiment of the present invention. It should be noted that the magnetically coupled reactor device according to this embodiment comprises a housing 108 with an upper opening and made of a material having good thermal conductivity, such as metal (aluminum, etc.), a reactor body 100 housed within the housing 108, and an insulating filler material 110 injected between the housing 108 and the reactor body 100.

[0044] In this embodiment, a case where an E-shaped core having three legs arranged to protrude at right angles to a base core portion (yoke portion: hereinafter simply referred to as a base core portion) is used will be described.

[0045] <Main Components of a Magnetic Coupling Reactor Device>

[0046] <Core>

[0047] The magnetic coupling type reactor device 200 according to the embodiment of the present invention is a magnetic coupling type structure, and its main parts are as follows: Figure 1 as well as Figure 2 As shown, a pair of E-shaped cores 101A, 101B are arranged so that the front ends of the legs (two outer leg cores 101A1, 101A2, middle leg core 101A3, and two outer leg cores 101B1, 101B2, middle leg core 101B3) protruding at right angles from the base cores 101A4, 101B4 are opposed to each other, so that Figure 2 As shown, a core portion in the shape of a Japanese character is formed. In addition, the coils 103A and 101B are respectively wound around the middle leg core portions 101A3 and 101B3 and assembled.

[0048] Furthermore, the corners of these E-shaped cores 101A and 101B are chamfered to form shoulders 101C1, 101C2, 101D1, and 101D2. That is, since magnetic flux does not easily flow through these corners, chamfering is performed to remove these corners and make the core more compact.

[0049] Furthermore, the core member constituting the core is formed of an iron material. Using an iron-based material allows for high magnetic density, and this structure allows for a higher degree of coupling, which is easily reduced. Examples of iron-based materials include electromagnetic steel sheets, powder cores (pure iron, Fe-Si-Al alloys, Ni-Fe-Mo alloys, Ni-Fe alloys), and amorphous materials.

[0050] In addition, the front ends of the E-shaped cores 101A and 101B may be directly butted against each other, but a spacer may be interposed between the front ends, or an air gap may be provided.

[0051] <Coil>

[0052] The coils 103A and 103B are formed by winding a flat wire using an edgewise winding method. Figure 1 As shown in the figure, a flat conductor wire is typically used, with a thickness of 0.5 to 6.0 mm and a width of 1.0 to 16.0 mm. Using flat conductor wire increases the space factor, enabling compactness and providing advantages against the skin effect. However, other cross-sectional shapes, such as round or rectangular conductor wire, can also be used.

[0053] The two coils 103A and 103B are wound so that the DC magnetic fluxes generated by each coil cancel each other out (this will be described later). These coils 103A and 103B are pre-wound into a cylindrical shape and, when housed in the housing 108, are inserted into the center leg core portions 101A3 and 101B3 of the E-shaped cores 101A and 101B, thereby being combined with the core portions.

[0054] That is, when current flows from one end of coil 103A and one end of coil 103B to the other end, the magnetic flux flowing in middle leg core 101A3 and the magnetic flux flowing in middle leg core 101B3 become opposite directions to each other, and the magnetic fluxes passing through the two middle leg cores 103A and 103B cancel each other out. The order of the magnetic flux rings surrounded by the cores 101A and 101B.

[0055] Note that, since a two-phase reactor device is formed using these two coil portions 103A and 103B, the device can be made more compact compared to providing two one-phase reactor devices.

[0056] Furthermore, by providing the coil portions 103A and 103B in the middle leg core portions 101A3 and 101B3 of the E-shaped cores 101A and 101B, respectively, the entire device has a symmetrical shape, and magnetic coupling becomes more efficient.

[0057] <Resin Molded Body>

[0058] The E-shaped cores 101A and 101B are housed in a state of being embedded in a resin molded body (including the bobbins of the coils 103A and 103B and the covers of the cores 101A and 101B) 105A and 105B, respectively. In this state, they are formed integrally with the resin molded bodies 105A and 105B by filling the mold with resin. The E-shaped cores 101A and 101B are insulated from the coils 103A and 103B by sandwiching the resin molded bodies 105A and 105B between the E-shaped cores 101A and 101B and the coils 103A and 103B. As the resin molded body material, for example, unsaturated polyester resin, polyurethane resin, epoxy resin, PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), etc., as well as materials obtained by adding glass and thermally conductive fillers to the above-mentioned resin molded body materials can be used.

[0059] <Magnetic coupling type reactor device>

[0060] Figure 3This figure shows a schematic perspective view of a magnetically coupled reactor device according to this embodiment. This magnetically coupled reactor device 200 is screwed to a base (not shown) on which it is mounted. Specifically, a housing 108 made of a metal such as aluminum has screw fastening portions 108A formed on four sides. Screws (not shown) are screwed into the base via threaded holes 108B in these screw fastening portions 108A, thereby enabling the magnetically coupled reactor device 200 to be mounted to the base. The front ends of the aforementioned E-shaped cores 101A and 101B can be directly butted together, but a spacer can also be interposed between them, or one or more air gaps can be provided. Specifically, one or more air gaps can be provided in the center leg core portions 101A3 and 101B3, or, alternatively or in addition thereto, one or more air gaps can be provided in the outer leg core portions 101A1, 101A2, 101B1, and 101B2. Here, "setting one or more air gaps" means dividing the core into multiple parts and setting space between the divided core parts, or filling the space between the core parts with non-magnetic materials (such as PET (polyethylene terephthalate), phenolic resin, the aforementioned resin molding material, etc.).

[0061] Furthermore, housing 108 houses a reactor body composed of E-shaped cores 101A, 101B and coils 103A, 103B. Resin molded bodies (bobbins) 105A, 105B are interposed between these E-shaped cores 101A, 101B and coils 103A, 103B to provide insulation. Furthermore, the reactor body is restrained from above and secured within housing 108. The resin molded body (bobbin) is secured to housing 108 by bolts 107.

[0062] In addition, resin terminal plates 106A and 106B are installed at two locations in the housing 108, forming a structure for indicating metal terminals 103C1, 103D1, 103C2, and 103D2 connected to the input ends 103A1 and 103B1 of each coil 103A and 103B and the output ends 103A2 and 103B2 of each coil 103A and 103B.

[0063] Furthermore, the reactor body is provided with a thermistor 109 for measuring the temperature of the reactor body, and a filler 110 for filling the gaps inside the housing 108 to achieve uniform heat distribution. Filler 110 can be made of a polyurethane resin, epoxy resin, acrylic resin, silicone resin, or the like, or can be cured using a liquid or gel-like material obtained by adding a thermally conductive filler to the above-mentioned fillers.

[0064] However, in this embodiment, by limiting the ratio of the cross-sectional area of the middle leg core portion 101A3 to the cross-sectional area of the outer leg core portions 101A1 and 101A2 to a predetermined range, the self-inductance can be increased, and the DC superposition characteristics can be improved.

[0065] That is, for example Figure 4 As shown in the cross-sectional view of the reactor body, a middle leg core portion 101A3 formed by winding and assembling a coil portion 103A is arranged in the center, and outer leg core portions 101A1 and 101A2 are arranged on both sides of the middle leg core portion 101A3.

[0066] Here, the structure is such that, when the cross-sectional area of the center leg core 101A3 is Si and the cross-sectional area of the outer leg cores 101A1 and 101A2 (the cross-sectional area of either outer leg core 101A1 or 101A2) is So, the following conditional expression (1) is satisfied. It should be noted that the cross-sectional area here refers to a cross-sectional area in a direction perpendicular to the axis of each leg.

[0067] 1.0≤Si / So≤5.0 (1)

[0068] Figure 5 Is the value of inductance (μH) relative to the above Si / So (in Figure 5 In the chart, the change of the cross-sectional area of the middle leg / cross-sectional area of the outer leg is recorded. Figure 5 The value of Si / So reaches its maximum at around 2 to 2.5, and when it is less than 1, the inductance value decreases sharply.

[0069] In this embodiment, since the lower limit of Si / So is set to 1.0 and the upper limit is set to 5.0, a magnetically coupled reactor device can be provided in which the inductance can be set to approximately 400 μH or more, the self-inductance can be set to a relatively large value, and the DC superposition characteristics can be further improved.

[0070] It should be noted that it is desirable to use the following conditional expression (2) instead of conditional expression (1).

[0071] 1.5≤Si / So≤3.5 (2)

[0072] Thus, by setting the lower limit of Si / So to 1.5 and the upper limit to 3.5, a magnetic coupling reactor device can be provided that has an inductance of approximately 450 μH or more, a higher self-inductance, and further excellent DC superposition characteristics.

[0073] Furthermore, it is more desirable to use the following conditional expression (3) instead of conditional expression (2).

[0074] 1.5≤Si / So≤3.0 (3)

[0075] As described above, by setting the lower limit of Si / So to 1.5 and the upper limit to 3.0, the inductance can be set to 450 μH or more, the self-inductance can be set to a further large value, and the DC superposition characteristics can be further improved.

[0076] use Figure 6 A core shape of a modified example for promoting a lower height in the magnetic coupling reactor device according to the present embodiment will be described.

[0077] That is, Figure 6 As shown in the cross-sectional view of the reactor body, a center leg core 101A3 formed by winding a coil 103A is arranged in the center, and outer leg cores 101A1 and 101A2 are arranged on both sides of the center leg core 101A3. Filler 110 is injected between the components.

[0078] In this modification, if Figure 6 As shown, the input end 103A1 and the output end 103A2 are led out horizontally from the wound coil 103A. The led out input end 103A1 is placed on the bobbin 105A above the outer leg core 101A2. In addition, the led out output end 103A2 is placed on the bobbin 105A above the outer leg core 101A1. Figure 6 In the embodiment, the height of the coil 103A becomes minimum when the upper side of the winding portion is aligned with the led-out input end 103A1 and the led-out output end 103A2.

[0079] Therefore, in this modification, middle leg core portion 101A3 is arranged offset upward relative to outer leg core portions 101A1 and 101A2 and accommodated in the hollow portion of coil 103A, thereby ensuring a low height of the reactor body.

[0080] exist Figure 6 In the embodiment, a heat conducting member 111 is disposed between the lower surface of the coil 103A and a heat sink (not shown), and the coil 103A is placed on the heat conducting member 111. This allows the surface of the member that contacts the heat sink to be flat, thereby increasing the efficiency of heat conduction to the heat sink and improving heat dissipation.

[0081] The offset amount of the center leg core portion 101A3 is obtained by adding the width of the coil 103A, the distance for ensuring insulation, and the assembly margin, i.e., a total of the sum of the widths.

[0082] A description will be given of a means for improving the degree of freedom in the layout of the terminal portions in the magnetic coupling reactor device according to the present embodiment.

[0083] like Figure 3 As shown, in this magnetically coupled reactor device 200, terminal block 106A is provided with end connections 103C1 and 103D1. Current from these end connections 103C1 and 103D1 is input to coils 103A and 103B via the coil input ends 103A1 and 103B1. Specifically, the current input ends of coils 103A and 103B are located on one side of coils 103A and 103B. Meanwhile, terminal block 106B is provided with end connections 103C2 and 103D2. Current from coils 103A and 103B is output to these end connections 103C2 and 103D2 via output ends 103A2 and 103B2. Specifically, coils 103A and 103B are arranged so that the current output ends are located on the other side of coils 103A and 103B, opposite the current input ends.

[0084] In this way, the input ends of the two coils 103A and 103B are aligned and the positions of the output ends are aligned, so that high efficiency can be achieved in the design around the terminal part. However, it is necessary to set a structure in which the magnetic flux passing through the coils 103A and 103B flows in opposite directions when the current flows in the coils 103A and 103B to cancel the magnetic flux. Therefore, the winding directions of the coils 103A and 103B are opposite to each other between the two coils 103A and 103B.

[0085] This can reduce the loss in wiring, improve the degree of freedom in the layout of the terminal portion, and reduce the height.

[0086] In addition, use Figure 7 A description will be given of a core shape according to another modified example for promoting a lower profile in the magnetic coupling reactor device of the present embodiment.

[0087] exist Figure 7 In the modified example shown, the reactor body 100A is composed of a pair of E-type cores 101A and 101B and a pair of coils 103A and 103B. Figure 3 The magnetically coupled reactor device 200 shown in the figure has the same reactor body 100 as the reactor body 100, but the input ends 113A1 and B1 and the output ends 113A2 and 113B2 of the coils 113A and 113B are all extended to one side of the coils 103A and 103B. Furthermore, the height of the outer core legs 101A2 and 101B2 on the side where the coils 103A and 103B extend is lower than the height of the outer core legs 101A1 and 101B1 and the base cores 101A4 and 101B4 on the other side by an amount corresponding to the width of the coils 113A and 113B. This improves the self-inductance and reduces wiring losses.

[0088] As described above, it is desirable that the cross-sectional areas of the outer leg cores 101A2 and 101B2 on one side (the wiring extraction side) and the outer leg cores 101A1 and 101B1 on the other side are equal. As described above, there is a height difference between the outer leg cores 101A2 and 101B2 on one side and the outer leg cores 101A1 and 101B1 on the other side. As a result, in order to make the cross-sectional areas of the two equal, Figure 8 As shown in the magnetically coupled reactor device 200A, the lateral width of the outer leg core portions 101A2 and 101B2 on one side (the wiring lead-out side) is greater than the lateral width of the outer leg core portions 101A1 and 101B1 on the other side. Specifically, when the height of the outer leg core portions 101A2 and 101B2 is H1 and the lateral width is W1, and the height of the outer leg core portions 101A1 and 101B1 is H2 and the lateral width is W2, the lateral widths W1 and W2 are adjusted so that the equation H1 × W1 = H2 × W2 holds. This allows the overall size of the reactor body 100A to be reduced.

[0089] Furthermore, as described above, when the height of the outer leg cores 101A2 and 101B2 on the side from which the coils 103A and 103B are led out is lowered, the filler 110 for heat dissipation may only be filled to the height of the outer leg cores 101A2 and 101B2.

[0090] Therefore, if Figure 9 As shown, a resin member 121 made of a material different from the filler material 110 is disposed in the region above the outer leg cores 101A2 and 101B2. The height of the outer leg cores 101A2 and 101B2, including the resin member 121, is approximately the same as the height of the outer leg cores 101A1 and 101B1. Therefore, the filler material 110 can be filled to the height of the outer leg cores 101A1 and 101B1. This improves heat dissipation performance.

[0091] The resin member 121 is preferably a material having fluidity in order to facilitate filling, and is further preferably insulating and inexpensive. Specific examples of the material include phenolic resin and PPS (polyphenylene sulfide resin).

[0092] It should be noted that in the assembly process of the magnetically coupled inductor device of this embodiment, the coil portions 103A and 103B are formed into a cylindrical shape in advance, and the E-shaped cores 101A and 101B are passed through the hollow portions of the coils 103A and 103B, thereby forming a state in which the coils 103A and 103B are wound around the E-shaped cores 101A and 101B.

[0093] The magnetic coupling reactor device according to the present invention is not limited to the above-described embodiment, and various other modifications are possible.

[0094] For example, in the magnetically coupled inductor device of the above-mentioned embodiment, two E-shaped cores each having three leg core portions protruding from a base core portion are combined to form a core portion, but the magnetically coupled inductor device of the present invention is not limited to this and can be constructed in the form of a multi-leg core component having any number of more than two leg core portions protruding from a base core portion.

[0095] Furthermore, when a multi-leg core member having four or more leg core portions projecting from a base core portion is used, winding can be performed on any middle leg core portion. Furthermore, any multi-phase core member of two or more phases can be used in each multi-leg core member.

[0096] Furthermore, the cross-sectional shape of the multi-leg core member may not be rectangular, but may be other shapes such as a circle or an ellipse.

[0097] In the above description, one coil is provided in the center leg core portion of each E-shaped core, but any number of coils may be provided in one center leg core portion 101A3 or 101B3. However, it is preferable to configure the core portion 101A3 or 101B3 to be symmetrical as a whole.

[0098] In addition, the two coil portions 103A and 103B are wound in a direction such that the magnetic fluxes generated in the middle leg core portions 101A3 and 101B3 cancel each other out as described above. Therefore, it is preferred that the directions of the currents flowing through the two coil portions are the same and the flat wires are wound in opposite directions as described above. However, by setting the directions of the currents flowing through the two coils 103A and 103B to opposite directions and winding the flat wires in the same direction, the effect of canceling out the magnetic fluxes generated in each coil 103A and 103B can be achieved.

Claims

1. A magnetic coupling reactor device, characterized in that: The magnetic coupling reactor device includes at least one pair of multi-leg core members, each of which is made of an iron-based material and includes a base core portion and three or more leg core portions protruding in the same direction from the base core portion. The at least one pair of multi-leg core components are arranged in a manner that the corresponding leg core parts are butted against each other, and at least one corresponding leg core part for coil winding is selected from the corresponding leg core parts, excluding the two outer leg core parts, and the inner leg core parts, and the coil parts are respectively assembled in a wound state at the positions of the butt joint parts of the selected corresponding leg core parts for coil winding, sandwiching the inner leg core parts, thereby forming a magnetic coupling type structure. The magnetic coupling type reactor device is constructed such that the respective input ends and output ends of the coil parts formed by the corresponding coil winding leg core parts of the pair of multi-leg core components are led out to the upper end surface of the outer leg core part on one side, and the height of the outer leg core part on one side is set to be lower than the height of the outer leg core part on the other side by a dimension corresponding to the width of the coil part. When the cross-sectional area of the coil winding leg core portion perpendicular to the extension direction of the coil winding leg core portion is Si, and the cross-sectional area of each of the two outer leg core portions perpendicular to the extension direction of the two outer leg core portions is So, the following conditional expression (1) holds true: 1.0≤Si / So≤5.0 (1) 2. The magnetic coupling reactor device according to claim 1, wherein: The scope of the above conditional expression (1) is limited to the scope of the following conditional expression (2), 1.5≤Si / So≤3.5 (2).

3. The magnetic coupling reactor device according to claim 1, wherein: The scope of the above conditional expression (1) is limited to the scope of the following conditional expression (3), 1.5≤Si / So≤3.0 (3).

4. The magnetic coupling reactor device according to claim 1, wherein: The multi-leg core member is composed of an E-shaped core member. The magnetic coupling reactor device is formed by assembling one coil portion in a wound state on each of the coil winding leg core portions, that is, the middle leg core portions, of the E-shaped core member.

5. The magnetic coupling reactor device according to claim 4, characterized in that: The middle leg core portion is offset upward from the two outer leg core portions by at least the width of the coil portion.

6. The magnetic coupling reactor device according to claim 4, characterized in that: Each corner of the E-shaped core member is chamfered so as to extend in the thickness direction of the E-shaped core member.

7. The magnetic coupling reactor device according to claim 5, characterized in that: The input ends of the coils respectively mounted on the corresponding coil winding leg core portions of the pair of multi-leg core members are arranged on one side with respect to the axis of the multi-leg core member, and the winding directions of the coils are opposite to each other.

8. The magnetic coupling reactor device according to claim 1, wherein: The cross-sectional area of the outer leg core portion on one side in a direction perpendicular to the axis is formed to be equal to the cross-sectional area of the outer leg core portion on the other side in a direction perpendicular to the axis, and in these two cross-sections, the cross-sectional area of the one side is formed to be lower in height and wider in width than the cross-sectional area of the other side.

9. The magnetic coupling reactor device according to claim 1, wherein: The magnetically coupled inductor device is formed by installing a resin material having a thickness equivalent to the difference in height between the outer leg core portion on one side and the outer leg core portion on the other side on the upper surface of the outer leg core portion on the one side to the respective input and output ends where the coil portion is not configured.

10. The magnetic coupling reactor device according to claim 4, characterized in that: One or more air gaps are provided in the mid-leg core portion.

11. The magnetic coupling reactor device according to claim 4, characterized in that: One or more air gaps are provided in at least one of the two outer leg core portions.

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