Reactor, Converter, and Power Conversion Device

Abstract

A reactor includes a coil and a magnetic core. The coil has a first winding portion. The magnetic core includes an intermediate core, a first end core, a second end core, a first side core, and a second side core. At least one of the first side core and the second side core has an inner concave portion provided on an inner surface facing the first winding portion in the Y direction. When the magnetic core is viewed from the Z direction, at least a part of the inner concave portion overlaps with a range of the length in the X direction in the first winding portion. The X direction is a direction along the axial direction of the intermediate core, the Y direction is a direction in which the intermediate core, the first side core, and the second side core are arranged side by side, and the Z direction is a direction orthogonal to the X direction and the Y direction.

Description

Technical Field

[0001] The present disclosure relates to a reactor, a converter, and a power conversion device.

[0002] This application claims priority based on Japanese Patent Application No. 2020-059196 filed on March 27, 2020, and incorporates by reference all the descriptions recorded in the said Japanese application. Background Art

[0003] A reactor is a component of a converter provided in a hybrid vehicle or the like. The reactor includes: a coil having a winding portion formed by winding a wire in a spiral shape; and a magnetic core assembled to the coil. For example, in Patent Document 1 Figures 5 to 8 a reactor with one winding portion is disclosed. The magnetic core of this reactor includes an intermediate core disposed inside the winding portion, a side core disposed outside the outer peripheral surface of the winding portion, and an end core disposed on the end surface of the winding portion.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-201509 Summary of the Invention

[0007] The reactor of the present disclosure

[0008] includes a coil and a magnetic core,

[0009] the coil has a first winding portion,

[0010] the magnetic core includes:

[0011] an intermediate core disposed inside the first winding portion;

[0012] a first end core facing the first end surface of the first winding portion;

[0013] a second end core facing the second end surface of the first winding portion;

[0014] a first side core disposed outside the first side surface of the first winding portion and connecting the first end core and the second end core; and

[0015] a second side core disposed outside the second side surface of the first winding portion and connecting the first end core and the second end core,

[0016] at least one of the first side core and the second side core has an inner concave portion provided on an inner surface, which is a surface facing the first winding portion in the Y direction,

[0017] When looking down at the magnetic core from the Z direction, at least a part of the inner recess overlaps with the range of the length of the first winding part in the X direction.

[0018] The X direction is the direction along the axial direction of the intermediate core.

[0019] The Y direction is the direction in which the intermediate core, the first side core, and the second side core are arranged side by side.

[0020] The Z direction is the direction orthogonal to the X direction and the Y direction.

[0021] The converter of the present disclosure includes the reactor of the present disclosure.

[0022] The power conversion device of the present disclosure includes the converter of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic perspective view of the reactor according to Embodiment 1.

[0024] Figure 2 is Figure 1 a top view of the reactor.

[0025] Figure 3 is a top view of the reactor shown in Embodiment 2.

[0026] Figure 4 is a top view of the reactor shown in Embodiment 3.

[0027] Figure 5 is a configuration diagram schematically showing the power supply system of a hybrid vehicle.

[0028] Figure 6 is a schematic circuit diagram showing an example of the outline of a power conversion device including a converter.

[0029] Figure 7 is a graph showing the relationship between the width of the inner recess and the magnetic characteristics in Test Example 1.

[0030] Figure 8 is a graph showing the relationship between the depth of the inner recess and the magnetic characteristics in Test Example 1. DETAILED DESCRIPTION

[0031] [Problems to be Solved by the Present Disclosure]

[0032] With the development of hybrid vehicles and the like, weight reduction of the reactor is required. However, when the magnetic core is miniaturized to achieve weight reduction of the reactor, the magnetic characteristics of the reactor deteriorate.

[0033] Therefore, one of the objectives of the present disclosure is to provide a reactor that is lightweight and has excellent magnetic properties. Additionally, one of the objectives of the present disclosure is to provide a converter and a power conversion device that include a reactor that is lightweight and has excellent magnetic properties.

[0034] [Effects of the Present Disclosure]

[0035] The reactor of the present disclosure is lightweight and has excellent magnetic properties. Additionally, the converter and the power conversion device of the present disclosure are lightweight and have excellent conversion efficiency.

[0036] [Description of Embodiments of the Present Disclosure]

[0037] First, embodiments of the present disclosure will be described by way of example.

[0038] <1> Reactor of the Embodiment

[0039] It includes a coil and a magnetic core.

[0040] The coil has a first winding portion.

[0041] The magnetic core includes:

[0042] An intermediate core, disposed inside the first winding portion;

[0043] A first end core, facing the first end face of the first winding portion;

[0044] A second end core, facing the second end face of the first winding portion;

[0045] A first side core, disposed outside the first side face of the first winding portion, connecting the first end core and the second end core; and

[0046] A second side core, disposed outside the second side face of the first winding portion, connecting the first end core and the second end core.

[0047] At least one of the first side core and the second side core has an inner concave portion provided on an inner surface, which is a surface facing the first winding portion in the Y direction.

[0048] When looking down at the magnetic core from the Z direction, at least a part of the inner concave portion overlaps with the range of the length of the first winding portion in the X direction.

[0049] The X direction is the direction along the axial direction of the intermediate core.

[0050] The Y direction is the direction in which the intermediate core, the first side core, and the second side core are arranged side by side.

[0051] The Z direction is the direction orthogonal to the X direction and the Y direction.

[0052] Here, the inner concave portions provided in the first side core can be either single or multiple. Similarly, the inner concave portions provided in the second side core can also be either single or multiple.

[0053] By providing inner concave portions in at least one of the first side core and the second side core, the solid portions of the two side cores are reduced, so the weight of the magnetic core, that is, the weight of the reactor, is reduced.

[0054] When inner concave portions are provided on the inner surfaces of the two side cores facing the first winding portion, the magnetic fluxes flowing through the two side cores meander in a direction away from the first winding portion. Due to the inner concave portions, the cross-sectional area of the magnetic paths of the two side cores is reduced, but the leakage magnetic fluxes from the two side cores to the coil are reduced. Therefore, the coil losses generated in the coil are reduced, so even if the cross-sectional area of the magnetic paths of the two side cores is reduced due to the inner concave portions, a decrease in the magnetic characteristics of the reactor can be suppressed.

[0055] When inner concave portions are provided in the two side cores, even if the two side cores are arranged close to the first winding portion, the coil losses are not likely to increase. Therefore, by arranging the two side cores close to the first winding portion, the size of the reactor in the Y direction becomes smaller. Compared with the reactor of this embodiment, in an existing reactor without inner concave portions, when the two side cores are arranged far from the first winding portion in order to reduce the coil losses, the reactor becomes larger in the Y direction.

[0056] <2>As one mode of the reactor of the embodiment, the following mode can be cited.

[0057] The first side core and the second side core each include the inner concave portion.

[0058] Since both the first side core and the second side core include inner concave portions, the weight of the magnetic core is significantly reduced.

[0059] <3>As one mode of the reactor of the embodiment, the following mode can be cited.

[0060] When looking at the magnetic core from the Z direction in plan view, the inner concave portion is formed within the range of the length of the first winding portion in the X direction.

[0061] Because the leakage magnetic fluxes to the first winding portion at the positions of the inner concave portions are reduced, when a part of the inner concave portion is outside the range of the length of the first winding portion, the portion outside this range is difficult to contribute to the reduction of the coil losses. On the other hand, as shown in the above structure, by forming the width of the inner concave portion within the range of the length of the first winding portion, it is easy to obtain the effect of reducing the coil losses brought about by providing the inner concave portion.

[0062] <4>As one mode of the reactor of the embodiment, the following mode can be cited.

[0063] The inner concave portion is in the form of a groove extending along the Z direction.

[0064] When the inner concave portion is in the form of a groove extending in the Z direction, by increasing the length of the inner concave portion in the Z direction, the reduction amount of the side cores based on the inner concave portion becomes larger. The longer the length of the inner concave portion in the Z direction, the larger the area of the inner concave portion facing the first winding portion. Therefore, the leakage magnetic flux from the two side cores to the first winding portion is reduced, and the coil loss of the reactor is easily reduced.

[0065] <5>As one mode of the reactor of the above <4>, the following mode can be cited.

[0066] The cross-sectional shape of the inner concave portion orthogonal to the Z direction is rectangular.

[0067] The inner concave portion with a rectangular or trapezoidal cross-sectional shape is easy to form. In addition, compared with the inner concave portion with a semi-circular cross-sectional shape or the like, the inner concave portion with a rectangular or trapezoidal cross-sectional shape can reduce the volume of the two side cores to a greater extent. When the reduction amount of the volume of the two side cores is large, the weight of the magnetic core is easily reduced.

[0068] <6>As one mode of the reactor of the embodiment, the following mode can be cited.

[0069] The first side core and the second side core are formed bodies of a composite material in which soft magnetic powder is dispersed in resin.

[0070] When the two side cores having the inner concave portion are formed bodies of a composite material, it is easier to suppress the deterioration of the magnetic characteristics of the magnetic core compared with the case where the two side cores are compacted powder formed bodies. This is confirmed by the results of Test Example 2 described later.

[0071] <7>As one mode of the reactor of the embodiment, the following mode can be cited.

[0072] When looking down at the magnetic core from the Z direction,

[0073] The width of the inner concave portion in the X direction is 5% or more and 70% or less of the axial length of the first winding portion.

[0074] Here, in the case where there are a plurality of inner concave portions provided on each side core, the total width of the plurality of inner concave portions in each side core is 5% or more and 70% or less of the axial length of the first winding portion.

[0075] When the width of the inner concave portion in the X direction is 5% or more and 70% or less of the axial length of the first winding portion, the magnetic characteristics of the reactor are not greatly deteriorated, and the weight of the magnetic core is greatly reduced. This is confirmed by the results of Test Example 1 described later.

[0076] <8>As one mode of the reactor according to the embodiment, the following mode can be cited.

[0077] When looking down at the magnetic core from the Z direction,

[0078] The depth of the inner concave portion in the Y direction is 5% or more and 50% or less of the length of the side core having the inner concave portion in the Y direction.

[0079] When the depth of the inner concave portion of each side core in the Y direction is 5% or more and 50% or less of the length of each side core in the Y direction, it is possible to suppress an excessive reduction in the magnetic path cross-sectional area of the side core. Therefore, the magnetic characteristics of the reactor are not easily reduced.

[0080] <9>The converter according to the embodiment includes the reactor according to any one of <1> to <8> above.

[0081] The above converter includes the reactor according to the embodiment that is lightweight and has excellent magnetic characteristics. Therefore, the above converter is lightweight and has excellent conversion efficiency.

[0082] <10>The power conversion device according to the embodiment includes the converter according to <9> above.

[0083] The above power conversion device includes a converter that is lightweight and has excellent conversion efficiency. Therefore, the above power conversion device is lightweight and has excellent conversion efficiency.

[0084] [Details of the Embodiment of the Present Disclosure]

[0085] Hereinafter, an embodiment of the reactor of the present disclosure will be described based on the drawings. The same reference numerals in the drawings denote components having the same name. In addition, the present invention is not limited to the structure shown in the embodiment, but is shown in the claims, and it is desired to include all changes within the meaning and scope equivalent to the claims.

[0086] <Embodiment 1>

[0087] In Embodiment 1, based on Figure 1 、 2 the structure of the reactor 1 will be described. Figure 1 The shown reactor 1 is constituted by combining a coil 2 and a magnetic core 3. As one of the features of this reactor 1, it can be cited that an inner concave portion 4 is provided in a part of the magnetic core 3. Hereinafter, each structure included in the reactor 1 will be described in detail.

[0088] 《Coil》

[0089] The coil 2 has one first winding portion 21 ( Figure 1 、 Figure 2)。The first winding portion 21 is formed by winding a single winding wire without a joint portion in a spiral shape. The winding wire can be a known winding wire. The winding wire used in this method is a coated flat wire. The conductor wire of the coated flat wire is composed of a flat wire made of copper. The insulating coating portion of the coated flat wire is composed of enamel. The first winding portion 21 is composed of a flat coil obtained by flatly winding the coated flat wire.

[0090] The shape of the first winding portion 21 is a rectangular tube shape. A rectangle includes a square. That is, the end face shape of the first winding portion 21 is formed in a rectangular frame shape. Since the shape of the first winding portion 21 is a rectangular tube shape, compared with the case where the winding portion has a cylindrical shape with the same cross-sectional area, it is easy to increase the contact area between the first winding portion 21 and the installation object. Therefore, the reactor 1 is likely to dissipate heat to the installation object via the first winding portion 21. On this basis, it is easy to stably install the first winding portion 21 on the installation object. The corners of the winding portion 21 are rounded.

[0091] The end portions 2a and 2b of the first winding portion 21 extend to the outer peripheral side of the first winding portion 21 on one end side and the other end side in the axial direction of the first winding portion 21, respectively. At the end portions 2a and 2b of the first winding portion 21, the insulating coating portion is peeled off to expose the conductor wire. The exposed conductor wire is connected to a terminal member (not shown). The coil 2 is connected to an external device through this terminal member. The illustration of the external device is omitted. Examples of the external device include a power supply that supplies power to the coil 2.

[0092] 《Magnetic Core》

[0093] As Figure 2 shown, the magnetic core 3 includes an intermediate core 30, a first end core 31, a second end core 32, a first side core 33, and a second side core 34. In Figure 2 it, the boundaries of the respective cores 30, 31, 32, 33, and 34 are shown by double-dot dash lines. The intermediate core 30 is the part of the magnetic core 3 that has a portion disposed inside the first winding portion 21. The first end core 31 is the part of the magnetic core 3 that faces the first end face 211 of the first winding portion 21. The second end core 32 is the part of the magnetic core 3 that faces the second end face 212 of the first winding portion 21. The first side core 33 is the part of the magnetic core 3 that is disposed outside the first side face 213 of the first winding portion 21. The second side core 34 is the part of the magnetic core 3 that is disposed outside the second side face 214 of the first winding portion 21.

[0094] In this magnetic core 3, a circular closed magnetic circuit shown by thick dashed lines is formed in the intermediate core 30, the first end core 31, the first side core 33, and the second end core 32. In addition, a circular closed magnetic circuit shown by thick dashed lines is formed in the intermediate core 30, the first end core 31, the second side core 34, and the second end core 32.

[0095] Here, the directions in the reactor 1 are defined based on the magnetic core 3. First, the direction along the axial direction of the middle core 30 is the X direction. The direction orthogonal to the X direction and in which the middle core 30, the first side core 33, and the second side core 34 are arranged in parallel is the Y direction. And the direction crossing both the X direction and the Y direction is the Z direction( Figure 1 ).

[0096] [Middle core]

[0097] The middle core 30 is the part of the magnetic core 3 disposed inside the first winding portion 21 of the coil 2. Therefore, the middle core 30 extends along the axial direction of the first winding portion 21. In this example, both end portions of the part of the magnetic core 3 along the axial direction of the first winding portion 21 protrude from the end faces 211 and 212 of the first winding portion 21. This protruding part is also a part of the middle core 30.

[0098] The shape of the middle core 30 is not particularly limited as long as it follows the internal shape of the first winding portion 21. The middle core 30 in this example is substantially rectangular parallelepiped-shaped.

[0099] [First end core / Second end core]

[0100] The first end core 31 and the second end core 32 are larger than the width of the first winding portion 21 in the Y direction. That is, the first end core 31 protrudes outward in the Y direction beyond the first end face 211 of the first winding portion 21, and the second end core 32 protrudes outward in the Y direction beyond the second end face 212 of the first winding portion 21.

[0101] The shapes of the first end core 31 and the second end core 32 are not particularly limited as long as sufficient magnetic paths are formed inside the respective end cores 31 and 32. The first end core 31 and the second end core 32 in this example are substantially rectangular parallelepiped-shaped. Two of the four corner portions of the first end core 31 and the second end core 32 viewed from the Z direction and located far from the side cores 33 and 34 may have rounded corners. When the two corner portions have rounded corners, the weights of the end cores 31 and 32 are reduced. The two corner portions are parts where magnetic flux hardly passes. Therefore, even if the two corner portions form rounded corners, the magnetic characteristics of the reactor 1 are not easily degraded.

[0102] [First side core / Second side core]

[0103] The first side core 33 connects the first end core 31 and the second end core 32 outside the first side face 213 of the first winding portion 21. The axial direction of the first side core 33 is parallel to the axial direction of the middle core 30. The first side face 213 is the face of the first winding portion 21 facing the Y direction.

[0104] The second side core 34 connects the first end core 31 and the second end core 32 on the outer side of the second side surface 214 of the first winding portion 21. The second side surface 214 is the surface of the first winding portion 21 facing the Y direction and is the surface facing the opposite direction of the first side surface 213. The axial direction of the second side core 34 is parallel to the axial direction of the intermediate core 30. In this example, the axis of the intermediate core 30, the axis of the first side core 33, and the axis of the second side core 34 are arranged on the XY plane.

[0105] The first side core 33 of this example is provided with an inner concave portion 4 on its inner surface 330. The inner surface 330 is the surface of the first side core 33 facing the first side surface 213 of the first winding portion 21. In addition, the second side core 34 of this example is provided with an inner concave portion 5 on its inner surface 340. The inner surface 340 is the surface of the second side core 34 facing the second side surface 214 of the first winding portion 21. Due to the inner concave portions 4 and 5, the weights of the two side cores 33 and 34 are reduced. Details of the inner concave portions 4 and 5 will be described later.

[0106] [Segmentation method]

[0107] The magnetic core 3 is composed of a plurality of chips so as to be assembled into the coil 2. The magnetic core 3 of this example is formed by combining two chips, the first chip 3A and the second chip 3B. The first chip 3A is composed of the first end core 31 and a part of the intermediate core 30. The shape of the first chip 3A viewed from the Z direction is substantially a T shape. On the other hand, the second chip 3B is composed of the second end core 32, the first side core 33, the second side core 34, and a part of the intermediate core 30. The shape of the second chip 3B viewed from the Z direction is substantially an E shape. Here, the number of segments of the magnetic core 3 can also be three or more as shown in, for example, Embodiment 2.

[0108] The total length in the X direction of the portion of the first chip 3A that becomes the intermediate core 30 and the total length in the X direction of the portion of the second chip 3B that becomes the intermediate core 30 are shorter than the length in the X direction of the first side core 33 or the length in the X direction of the second side core 34. Therefore, a gap portion 3g is formed between the first chip 3A and the second chip 3B inside the first winding portion 21. The gap portion 3g of this example is an air gap. A gap plate (not shown) can also be sandwiched in the gap portion 3g. Different from this example, the end surfaces of the first chip 3A and the second chip 3B can also be in contact inside the first winding portion 21. In this case, a gap portion can also be provided in at least one of the first end core 31 and the first side core 33 and between the first end core 31 and the second side core 34.

[0109] [Magnetic characteristics / Materials, etc.]

[0110] Each of the cores 30, 31, 32, 33, 34 of the magnetic core 3 is preferably a compacted powder compact formed by compacting a raw material powder containing soft magnetic powder, or a formed body of a composite material of soft magnetic powder and resin. All of the cores 30, 31, 32, 33, 34 may be compacted powder compacts, or all of the cores 30, 31, 32, 33, 34 may be formed bodies of composite materials. Further, a part of the cores 30, 31, 32, 33, 34 may be compacted powder compacts, and the remaining part may be formed bodies of composite materials. The magnetic core 3 in which a part is a compacted powder compact and the remaining part is a formed body of composite material is not easily magnetically saturated.

[0111] The soft magnetic powder of the compacted powder compact is an aggregate of soft magnetic particles composed of iron group metals such as iron, or ferroalloys such as Fe (iron)-Si (silicon) alloy and Fe-Ni (nickel) alloy. An insulating coating portion composed of phosphate or the like may be formed on the surface of the soft magnetic particles. The raw material powder may also contain a lubricating material or the like.

[0112] A formed body of a composite material can be manufactured by filling a mixture of soft magnetic powder and uncured resin into a mold and curing the resin. The soft magnetic powder of the composite material can use the same materials as those that can be used in the compacted powder compact. On the other hand, examples of the resin contained in the composite material include thermosetting resins, thermoplastic resins, room temperature curable resins, and low temperature curable resins. Examples of the thermosetting resin include unsaturated polyester resins, epoxy resins, urethane resins, and silicone resins. Examples of the thermoplastic resin include polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin, liquid crystal polymer (LCP), polyamide (PA) resins such as nylon 6 and nylon 66, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin, and the like. In addition, BMC (Bulk molding compound) in which calcium carbonate or glass fiber is mixed in unsaturated polyester, kneaded silicone rubber, kneaded urethane rubber, etc. can also be used.

[0113] When the above composite material further contains non-magnetic and non-metallic powders (fillers) such as alumina and silica in addition to the soft magnetic powder and the resin, the heat dissipation can be further improved. The content of the non-magnetic and non-metallic powder may be 0.2 mass% or more and 20 mass% or less, further 0.3 mass% or more and 15 mass% or less, 0.5 mass% or more and 10 mass% or less.

[0114] The content of the soft magnetic powder in the composite material can be, for example, 30% by volume or more and 80% by volume or less. From the viewpoints of improving the saturation magnetic flux density and heat dissipation, the content of the magnetic powder can further be set to 50% by volume or more, 60% by volume or more, 70% by volume or more. From the viewpoint of improving the fluidity during the manufacturing process, it is preferable to set the content of the magnetic powder to 75% by volume or less. In the formed body of the composite material, when the filling rate of the soft magnetic powder is adjusted to be low, it is easy to reduce its relative magnetic permeability. The relative magnetic permeability of the formed body of the composite material is, for example, 5 or more and 50 or less. The relative magnetic permeability of the formed body of the composite material can further be 10 or more and 45 or less, 15 or more and 40 or less, 20 or more and 35 or less. In this example, the entire second chip 3B including the inner concave portions 4 and 5 is made of the formed body of the composite material.

[0115] It is easier to increase the content of the soft magnetic powder in the compacted formed body than in the formed body of the composite material. For example, the content of the soft magnetic powder in the compacted formed body exceeds 80% by volume, and further is 85% by volume or more. The chip made of the compacted formed body is likely to be a chip with a high saturation magnetic flux density and relative magnetic permeability. The relative magnetic permeability of the compacted formed body is, for example, 50 or more and 500 or less. The relative magnetic permeability of the compacted formed body can also be 80 or more, 100 or more, 150 or more, 180 or more. In this example, the entire first chip 3A is made of the compacted formed body.

[0116] [Dimensions]

[0117] When the reactor 1 in this example is for vehicle use, the length L of the magnetic core 3 in the X direction is, for example, 30 mm or more and 150 mm or less, the width W of the magnetic core 3 in the Y direction is, for example, 30 mm or more and 150 mm or less, and the height H in the Z direction is, for example, 15 mm or more and 75 mm or less.

[0118] The length T0 of the intermediate core 30 in the Y direction is, for example, 10 mm or more and 50 mm or less. The length T1 of the first end core 31 in the X direction and the length T2 of the second end core 32 in the X direction are, for example, 5 mm or more and 40 mm or less. In addition, the length T3 of the first side core 33 in the Y direction and the length T4 of the second side core 34 in the Y direction are, for example, 5 mm or more and 40 mm or less. These lengths are related to the size of the magnetic path cross-sectional area of the magnetic core 3. The length T12 of the intermediate core 30 in the X direction is the length obtained by subtracting the length T1 and the length T2 from the length L of the magnetic core 3, and is, for example, 10 mm or more and 140 mm or less.

[0119] 《Inner Concave Portion in the First Side Core》

[0120] The first side core 33 has an inner concave portion 4 on its inner surface 330. The inner concave portion 4 may be a single one as shown in the figure or may be multiple. At least a part of the inner concave portion 4 overlaps with the range of the length T12 of the first winding portion 21 in the X direction when the core 3 is viewed from the Z direction. When the inner concave portion 4 is provided on the inner surface 330 of the first side core 33 facing the first winding portion 21, the magnetic flux flowing through the first side core 33 meanders in a direction away from the first winding portion 21. The magnetic path cross-sectional area of the first side core 33 decreases due to the inner concave portion 4, but the leakage magnetic flux from the first side core 33 to the coil 2 decreases. Therefore, the coil loss generated in the coil 2 decreases, so even if the magnetic path cross-sectional area of the first side core 33 decreases due to the inner concave portion 4, a decrease in the magnetic characteristics of the reactor 1 can be suppressed.

[0121] Here, since the leakage magnetic flux to the first winding portion 21 decreases at the position of the inner concave portion 4, when a part of the inner concave portion 4 is outside the range of the length T12 of the first winding portion 21, the portion outside this range is difficult to contribute to the reduction of the coil loss. Therefore, it is preferable that the inner concave portion 4 is accommodated within the range of the length T12 of the first winding portion 21 in the X direction. By forming the width W1 of the inner concave portion 4 within the range of the length T12 of the first winding portion 21, it is easy to obtain the effect of reducing the coil loss brought about by providing the inner concave portion 4.

[0122] It is preferable that the inner concave portion 4 is a groove shape extending in the Z direction. The inner concave portion 4 in this example has a length from the upper surface to the lower surface of the first side core 33 in the Z direction. The inner concave portion 4 with such a length has a high effect of reducing the weight of the first side core 33. Different from this example, the inner concave portion 4 may also be a length that does not reach the upper surface or the lower surface of the first side core 33.

[0123] The cross-sectional shape of the inner concave portion 4 orthogonal to the extending direction is not particularly limited. In this example, the cross-sectional shape of the inner concave portion 4 orthogonal to the extending direction is a rectangle. The so-called cross-sectional shape refers to the shape surrounded by the bottom surface 40 of the inner concave portion 4, two inner wall surfaces 41 and 42 opposite in the X direction, and the opening portion on the outer side in the Y direction. The corners of the rectangle may also have rounded corners. When the cross-sectional shape of the inner concave portion 4 is a rectangle, compared with inner concave portions having a semi-circular cross-sectional shape, a triangular cross-sectional shape, etc., the volume of the first side core 33 can be reduced more greatly. Different from this example, the cross-sectional shape of the inner concave portion 4 may also be a trapezoid with a widened opening portion. That is to say, the inner concave portion 4 with a trapezoidal cross-sectional shape is an inner concave portion 4 in which the distance between the inner wall surface 41 and the inner wall surface 42 becomes longer as it goes from the bottom surface 40 toward the opening portion. The corners of the trapezoid may also have rounded corners. The inner concave portion 4 with a trapezoidal cross-sectional shape can also reduce the volume of the first side core 33 more greatly compared with inner concave portions having a semi-circular cross-sectional shape, a triangular cross-sectional shape, etc.

[0124] The width W1 of the inner recess 4 in the X direction is preferably 5% or more and 70% or less of the length T12 of the intermediate core 30 in the X direction. A more preferable width W1 is 10% or more and 55% or less of the length T12. When there are a plurality of inner recesses 4 provided in the first side core 33, the total width of the plurality of inner recesses 4 in the first side core 33 is defined as the width W1 in the X direction. When the width W1 of the inner recess 4 in the X direction is 5% or more and 70% or less of the length T12 of the first winding portion 21 in the X direction, the magnetic characteristics of the reactor 1 are not greatly reduced, and the weight of the magnetic core 3 is greatly reduced. Here, the width W1 of the inner recess 4 refers to the width of the opening of the inner recess 4.

[0125] On the other hand, the depth D1 of the inner recess 4 in the direction is preferably 5% or more and 50% or less of the length T3 of the first side core 33 in the Y direction. A more preferable depth D1 is 10% or more and 35% or less of the length T3. When the depth D1 of the inner recess 4 in the first side core 33 is within the above range, it is possible to suppress an excessive reduction in the magnetic path cross-sectional area of the first side core 33. Therefore, the magnetic characteristics of the reactor 1 are not easily reduced. Here, the depth D1 of the inner recess 4 refers to the length from the opening of the inner recess 4 to the deepest part.

[0126] 《Inner Recess in the Second Side Core》

[0127] The structure of the inner recess 5 provided in the second side core 34 is the same as the structure of the inner recess 4 provided in the first side core 33. By changing "inner recess 4" in the description of the inner recess 4 to "inner recess 5", "first side core 33" to "second side core 34", and "length T3" to "length T4", the description of the inner recess 5 is obtained.

[0128] 《Another Example》

[0129] The magnetic core 3 of the reactor 1 may have a structure having only the inner recess 4 provided in the first side core 33, or may have a structure having only the inner recess 5 provided in the second side core 34.

[0130] 《Others》

[0131] The reactor 1 may further include at least one of a housing, an adhesive layer, a holding member, and a molded resin portion. The housing is a member that houses the combination of the coil 2 and the magnetic core 3 inside. The combination housed in the housing may be buried in a sealing resin portion. The adhesive layer is a layer that fixes the above combination to the mounting surface, or fixes the above combination to the inner bottom surface of the housing, or fixes the above housing to the mounting surface. The holding member is a member that is interposed between the coil 2 and the magnetic core 3 and ensures insulation between the coil 2 and the magnetic core 3. The molded resin portion is a structure that covers the outer periphery of the above combination and is interposed between the coil 2 and the magnetic core 3 to integrate the coil 2 and the magnetic core 3.

[0132] 《Effect》

[0133] The reactor 1 of this example having the inner concave portions 4 and 5 is lighter than the conventional reactor without the inner concave portions 4 and 5.

[0134] In the reactor 1 of this example, by providing the inner concave portion 4 in the first side core 33 and the inner concave portion 5 in the second side core 34, the solid portions of the both side cores 33 and 34 are reduced. Therefore, the reactor 1 is lightened. Further, since the solid portions of the both side cores 33 and 34 are reduced, the productivity of the magnetic core 3 including the cost, that is, the productivity of the reactor 1 is improved.

[0135] The reactor 1 of this example has magnetic characteristics equivalent to those of the reactor without the inner concave portions 4 and 5.

[0136] In the reactor 1 of this example, the inner concave portion 4 is provided on the inner surface 330 of the first side core 33, and the inner concave portion 5 is provided on the inner surface 340 of the second side core 34. Through these inner concave portions 4 and 5, the leakage magnetic flux from the both side cores 33 and 34 to the first winding portion 21 is reduced. Therefore, the coil loss generated by the leakage magnetic flux passing through the first winding portion 21 is reduced, and thus the deterioration of the magnetic characteristics of the reactor 1 can be suppressed.

[0137] <Embodiment 2>

[0138] Based on Figure 3 The reactor 1 of Embodiment 2 will be described. The divided state of the magnetic core 3 of the reactor 1 of Embodiment 2 is different from that of the reactor 1 of Embodiment 1. The structure of the reactor 1 of this example other than the divided state of the magnetic core 3 is the same as that of the reactor of Embodiment 1.

[0139] The magnetic core 3 of the reactor 1 of this example is constituted by combining the first chip 3A, the second chip 3B, the third chip 3C, and the fourth chip 3D. The first chip 3A of this example is constituted by the first end core 31 and a part of the intermediate core 30. The second chip 3B of this example is constituted by the second end core 32 and a part of the intermediate core 30. The first chip 3A and the second chip 3B viewed from the Z direction are substantially T-shaped. The first chip 3A and the second chip 3B of this example have the same shape and are manufactured by one mold.

[0140] On the other hand, the third chip 3C of this example is constituted by the first side core 33, and the fourth chip 3D of this example is constituted by the second side core 34. The inner concave portion 4 is provided in the first side core 33, and the inner concave portion 5 is provided in the second side core 34. The third chip 3C and the fourth chip 3D viewed from the Z direction are substantially I-shaped. The third chip 3C and the fourth chip 3D of this example have the same shape and are manufactured by one mold.

[0141] Each of the chips 3A, 3B, 3C, and 3D is a compacted powder compact or a compact of a composite material. For example, a mode can be cited in which the chips 3A and 3B are compacted powder compacts and the chips 3C and 3D are compacts of a composite material.

[0142] The reactor 1 according to this example can also achieve the same effects as the reactor 1 of the first embodiment. That is, the reactor 1 of this example is lightweight and has excellent magnetic properties.

[0143] <Embodiment 3>

[0144] Based on Figure 4 The reactor 1 of Embodiment 3 will be described. The divided state of the magnetic core 3 of the reactor 1 of Embodiment 3 is different from that of the reactors 1 of Embodiments 1 and 2. The structure of the reactor 1 in this example other than the divided state of the magnetic core 3 is the same as that of the reactors of Embodiments 1 and 2.

[0145] The magnetic core 3 of the reactor 1 in this example is constituted by combining a first chip 3A and a second chip 3B. The first chip 3A in this example is constituted by a first end core 31, a second end core 32, a first side core 33, and a second side core 34. An inner recess 4 is provided in the first side core 33, and an inner recess 5 is provided in the second side core 34. The first chip 3A viewed from the Z direction is substantially O-shaped. On the other hand, the second chip 3B in this example is constituted by an intermediate core 30. The second chip 3B viewed from the Z direction is substantially I-shaped.

[0146] Each of the chips 3A and 3B is a compacted powder compact or a compact of a composite material. For example, a mode can be cited in which the first chip 3A is a compact of a composite material and the second chip 3B is a compacted powder compact.

[0147] The reactor 1 according to this example can also achieve the same effects as the reactor 1 of the first embodiment. That is, the reactor 1 of this example is lightweight and has excellent magnetic properties.

[0148] <Embodiment 4>

[0149] 《Converter / Power Conversion Device》

[0150] The reactors 1 of Embodiments 1 to 3 can be used for applications that satisfy the following energization conditions. As the energization conditions, for example, a maximum DC current of about 100 A or more and 1000 A or less, an average voltage of about 100 V or more and 1000 V or less, and a use frequency of about 5 kHz or more and 100 kHz or less can be cited. The reactors 1 of Embodiments 1 to 3 can typically be used as components of a converter mounted on a vehicle such as an electric vehicle or a hybrid vehicle, or as components of a power conversion device including the converter.

[0151] Vehicles such as hybrid vehicles and electric vehicles 1200, as shown in FIG. 5, include a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and an electric motor 1220 that is driven by the supplied power from the main battery 1210 and is used for driving. The electric motor 1220 is typically a three-phase AC motor that drives the wheels 1250 during driving and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 further includes an engine 1300 in addition to the electric motor 1220. In Figure 6 FIG., a socket is shown as a charging part of the vehicle 1200, but it can be configured to have a plug.

[0152] The power conversion device 1100 includes a converter 1110 connected to the main battery 1210, and an inverter 1120 connected to the converter 1110 that performs mutual conversion between DC and AC. The converter 1110 shown in this example boosts the input voltage of the main battery 1210, which is in the range of 200V to 300V, to a level of 400V to 700V and supplies power to the inverter 1120 during vehicle 1200 driving. The converter 1110 steps down the input voltage output from the electric motor 1220 via the inverter 1120 to a DC voltage suitable for the main battery 1210 and charges the main battery 1210 during regeneration. The input voltage is a DC voltage. The inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC and supplies power to the electric motor 1220 during vehicle 1200 driving, and during regeneration, converts the AC output from the electric motor 1220 into DC and outputs it to the converter 1110.

[0153] The converter 1110, as Figure 6 shown, includes a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115, and performs conversion of the input voltage by repeating on / off. The conversion of the input voltage here is to perform step-up / step-down. The switching elements 1111 use power devices such as field effect transistors and insulated gate bipolar transistors. The reactor 1115 has the following function: using the coil property that impedes the change in the current flowing through the circuit, when the current is about to increase or decrease due to the switching operation, making its change smooth. As the reactor 1115, a reactor 1 of any one of Embodiment 1 to Embodiment 3 is provided. By providing a reactor 1 that is lightweight and has excellent magnetic characteristics, etc., the power conversion device 1100 and the converter 1110 are lightweight and have excellent conversion efficiency.

[0154] In addition to the converter 1110, the vehicle 1200 is also equipped with a converter 1150 for a power supply device connected to the main battery 1210, and an auxiliary power supply converter 1160 connected to the auxiliary battery 1230 and the main battery 1210, which are the power sources of the auxiliary machines 1240, and converts the high voltage of the main battery 1210 into low voltage. The converter 1110 typically performs DC-DC conversion, but the converter 1150 for the power supply device and the auxiliary power supply converter 1160 perform AC-DC conversion. There is also a converter in the converter 1150 for the power supply device that performs DC-DC conversion. The reactors of the converter 1150 for the power supply device and the auxiliary power supply converter 1160 have the same structure as the reactor 1 or the like in any of Embodiments 1 to 3, and reactors with appropriately changed sizes, shapes, etc. can be used. In addition, a converter that converts input power, and a converter that only steps up or only steps down can also use the reactor 1 or the like in any of Embodiments 1 to 3.

[0155] <Test>

[0156] <<Test Example 1>>

[0157] In Test Example 1, the influence of the width W1 of the inner concave portions 4 and 5 shown in Figure 2 on the inductance and total loss of the reactor 1 was investigated. Specifically, the reactor of Specimen No. 1 without the inner concave portions 4 and 5 and the reactors 1 of Specimens No. 2 to No. 6 with the inner concave portions 4 and 5 were analyzed. The only difference between the reactor of Specimen No. 1 and the reactors 1 of Specimens No. 2 to No. 6 is the presence or absence of the inner concave portions 4 and 5. In addition, the only difference between the reactors of Specimens No. 2 to No. 6 is the width W1 of the inner concave portions 4 and 5. The dimensions of the main part of the magnetic core 3 of each specimen are as follows.

[0158] [Specimen No. 1]

[0159] · Inner concave portions 4, 5... None.

[0160] · Length L of the magnetic core 3... 70 mm

[0161] · Width W of the magnetic core 3 = width W of the first end core 31 and the second end core 32... 75 mm

[0162] · Height H of the magnetic core 3... 30 mm

[0163] · Length T0 in the Y direction of the intermediate core 30... 30 mm

[0164] · Length T12 in the X direction of the intermediate core 30... 46 mm

[0165] · Lengths T1, T2 in the X direction of the first end core 31 and the second end core 32... 12 mm

[0166] · The lengths T3, T4 of the first side core 33 and the second side core 34 in the Y direction... 11 mm

[0167] [Specimen No. 2]

[0168] · The width W1 of the inner recess 4... 5 mm

[0169] The width W1 of the inner recess 4 is 10% of the length T12 of the middle core 30 in the X direction.

[0170] · The depths D1 of the inner recesses 4, 5... 2 mm

[0171] · The lengths of the inner recesses 4, 5 in the Z direction... 30 mm

[0172] [Specimen No. 3]

[0173] · The widths W1 of the inner recesses 4, 5... 10 mm

[0174] The widths W1 of the inner recesses 4, 5 are 21% of the length T12 of the middle core 30 in the X direction.

[0175] [Specimen No. 4]

[0176] · The widths W1 of the inner recesses 4, 5... 15 mm

[0177] The widths W1 of the inner recesses 4, 5 are 32% of the length T12 of the middle core 30 in the X direction.

[0178] [Specimen No. 5]

[0179] · The widths W1 of the inner recesses 4, 5... 20 mm

[0180] The widths W1 of the inner recesses 4, 5 are 43% of the length T12 of the middle core 30 in the X direction.

[0181] [Specimen No. 6]

[0182] · The widths W1 of the inner recesses 4, 5... 25 mm

[0183] The widths W1 of the inner recesses 4, 5 are 54% of the length T12 of the middle core 30 in the X direction.

[0184] The simulation experiments of the inductance and total loss of each sample were carried out using JMAG-Designer 18.1 (manufactured by JSOL Corporation), a commercially available software. In the analysis of inductance, the inductance (μH) when current flows through coil 2 was obtained. The current varied in the range of 0 A to 300 A. The inductances at current values of 0 A, 100 A, 200 A, and 300 A are shown in Table 1. The inductance is expressed as a percentage with the inductance of sample No. 1 at 0 A set to 100%.

[0185] In addition, in the analysis of total loss, the total loss (W) was obtained based on the magnetic flux density distribution and current density distribution when driven by a DC current of 0 A, an input voltage of 200 V, an output voltage of 400 V, and a frequency of 20 kHz. The total loss in this example includes the iron loss of core 3 and coil loss, etc. The results are shown in Table 1. The total loss and coil loss are expressed as a percentage with the total loss of sample No. 1 set to 100%.

[0186] Table 1 shows the volume reduction amount (mm 3 ) of core 3 caused by setting the inner square recess 4 together.

[0187] [Table 1]

[0188]

[0189] As shown in Table 1, compared with the reactor of sample No. 1 as the basic model, there is a tendency that the larger the width W1 of the inner square recesses 4 and 5, the greater the volume reduction amount of core 3, and the lower the inductance of reactor 1 at 0 A or 100 A. However, there is a tendency that the larger the width W1 of the inner square recesses 4 and 5, the higher the inductance of reactor 1 at 200 A or 300 A.

[0190] On the other hand, it can be seen that by setting the inner square recesses 4 and 5, the total loss in reactor 1 is reduced. In particular, the reduction of coil loss caused by setting the inner square recesses 4 and 5 is significant.

[0191] Furthermore, in order to investigate the relationship between the width W1 of the inner square recesses 4 and 5 and the degree of change in the coil loss in reactor 1, the reduction amount and reduction rate of the coil loss shown below were investigated.

[0192] [Reduction amount of coil loss]

[0193] ·(Reduction amount of coil loss)=(Coil loss of the basic model)-(Coil loss of the target model)

[0194] For example, the reduction amount of the coil loss of sample No. 2 is the value obtained by subtracting the coil loss of sample No. 2 from the coil loss of sample No. 1 as the basic model.

[0195] The reduction amounts of the coil losses of Specimens No. 2 to No. 6 are shown in Figure 7 using a bar graph. The horizontal axis of the graph is the specimen No., and the left vertical axis is the reduction amount of the coil loss (W).

[0196] [Reduction rate of coil loss]

[0197] ·(Reduction rate of coil loss) = (Reduction amount of coil loss) / (Reduction amount of core volume)

[0198] The reduction rates of the coil losses of Specimens No. 2 to No. 6 are shown in Figure 7 using a line graph. The horizontal axis of the graph is the specimen No., and the right vertical axis is the reduction rate of the coil loss. The vertical axis is a value obtained from the original data.

[0199] As shown in the line graph of Figure 7 , it can be known as follows: The larger the width W1 of the inner concave portions 4 and 5, the slower the reduction rate of the coil loss decreases, but the larger the reduction amount of the coil loss shown in the bar graph. As shown in Table 1, it can be known as follows: The larger the width W1 of the inner concave portions 4 and 5, the smaller the total loss of the entire reactor 1. Therefore, the width W1 of the inner concave portions 4 and 5 is preferably 20 mm or more and 25 mm or less.

[0200] <<Test Example 2>>

[0201] In Test Example 2, the influence of the depth D1 of the inner concave portions 4 and 5 shown in Figure 2 on the inductance and total loss of the reactor 1 was investigated. Specifically, the reactors of Specimen No. 1 without the inner concave portions 4 and 5 and the reactors 1 of Specimens No. 7 to No. 11 with the inner concave portions 4 and 5 were analyzed. The reactor of Specimen No. 1 is the same as the reactor of Specimen No. 1 in Test Example 1. The difference between the reactors 1 of Specimens No. 7 to No. 11 is only the depth D1 of the inner concave portions 4 and 5. The dimensions of the main portions of the magnetic cores 3 of each specimen are as follows.

[0202] [Specimen No. 7]

[0203] ·Depth D1 of the inner concave portions 4 and 5... 1 mm

[0204] The depth D1 of the inner concave portions 4 and 5 is 9% of the lengths T3 and T4 in the Y direction of the side cores 33 and 34.

[0205] ·Width W1 of the inner concave portions 4 and 5... 10 mm

[0206] ·Length in the Z direction of the inner concave portions 4 and 5... 30 mm

[0207] [Specimen No. 8]

[0208] · The depth D1 of the inner concave portion 4... 2 mm

[0209] The depth D1 of the inner concave portions 4 and 5 is 18% of the lengths T3 and T4 in the Y direction of the side cores 33 and 34.

[0210] [Specimen No. 9]

[0211] · The depth D1 of the inner concave portions 4 and 5... 3 mm

[0212] The depth D1 of the inner concave portions 4 and 5 is 27% of the lengths T3 and T4 in the Y direction of the side cores 33 and 34.

[0213] [Specimen No. 10]

[0214] · The depth D1 of the inner concave portions 4 and 5... 4 mm

[0215] The depth D1 of the inner concave portions 4 and 5 is 36% of the lengths T3 and T4 in the Y direction of the side cores 33 and 34.

[0216] [Specimen No. 11]

[0217] · The depth D1 of the inner concave portions 4 and 5... 5 mm

[0218] The depth D1 of the inner concave portions 4 and 5 is 45% of the lengths T3 and T4 in the Y direction of the side cores 33 and 34.

[0219] The inductance and total loss of each specimen were obtained by the same method as in Test Example 1. The results are shown in Table 2.

[0220] [Table 2]

[0221]

[0222] As shown in Table 2, compared with the reactor of Specimen No. 1 as the basic model, there is the following tendency: the larger the depth D1 of the inner concave portions 4 and 5, that is, the larger the volume reduction amount of the magnetic core 3, the lower the inductance of the reactor 1 at 0 A or 100 A. However, there is the following tendency: the larger the depth D1 of the inner concave portions 4 and 5, the higher the inductance of the reactor 1 at 200 A or 300 A.

[0223] On the other hand, it is known that by providing the inner concave portions 4 and 5, the total loss in the reactor 1 is reduced. In particular, by providing the inner concave portions 4 and 5, the reduction of the coil loss is significant.

[0224] Further, in order to investigate the relationship between the depths D1 of the inner square recesses 4 and 5 and the degree of change in the coil loss in the reactor 1, the reduction amount and reduction rate of the coil loss of each specimen were investigated. The definitions of the reduction amount and reduction rate of the coil loss are the same as those in Test Example 1. The results are shown in Figure 8 as follows. Figure 8 is used in the same way as Figure 7 the same.

[0225] As Figure 8 shown in the line graph, the greater the depths D1 of the inner square recesses 4 and 5, the more sharply the reduction rate of the total coil loss decreases. In addition, the reduction amount of the coil loss shown in the bar graph peaks at Specimen No. 10 and rather decreases at Specimen No. 11. Actually, as shown in Table 2, the total loss of the reactor 1 of Specimen No. 11 also decreases. Therefore, it can be known that the depths D1 of the inner square recesses 4 and 5 are preferably 3 mm or more and 4 mm or less.

[0226] 《Test Example 3》

[0227] In Test Example 3, it was investigated whether there are differences in the reduction rate of the magnetic properties caused by providing the inner square recesses 4 and 5 depending on whether the magnetic core 3 is a compacted powder formed body or a composite material. The information of each specimen is as follows. The dimensions L, W, H, T0, T1, T2, T3, and T4 of the magnetic core 3 of each specimen are the same as those of Specimen No. 1 in Test Example 1.

[0228] [Specimen No. 20]

[0229] · The entire magnetic core 3 is a compacted powder formed body.

[0230] · It does not have the inner square recesses 4 and 5.

[0231] [Specimen No. 21]

[0232] · The entire magnetic core 3 is a compacted powder formed body.

[0233] · It has the inner square recesses 4 and 5.

[0234] · The width W1 of the inner square recesses 4 and 5... 12 mm

[0235] · The depth D1 of the inner square recesses 4 and 5... 4 mm

[0236] [Specimen No. 22]

[0237] · The entire magnetic core 3 is a composite material.

[0238] · It does not have the inner square recesses 4 and 5.

[0239] [Specimen No. 23]

[0240] · The core 3 as a whole is a composite material.

[0241] · It has inner square recesses 4 and 5.

[0242] · The width W1 of the inner square recesses 4 and 5...12 mm

[0243] · The depth D1 of the inner square recesses 4 and 5...4 mm

[0244] The inductance and total loss of specimens No. 20 to No. 23 were measured. The measurement method was the same as in Test Example 1. The measurement results are shown in Table 3. The inductance in Table 3 is expressed as a percentage with the inductance of specimen No. 20 at 0 A set to 100%. In addition, the total loss in Table 3 is expressed as a percentage with the total loss of specimen No. 20 set to 100%. In the parentheses shown in each column of specimen No. 21 and specimen No. 23 in Table 3, the change rate relative to specimen No. 20 and specimen No. 22 is expressed as a percentage. When the change rate of inductance is positive, it can be considered that the magnetic characteristics of the reactor 1 improve. In addition, when the change rate of total loss is negative, it can be considered that the magnetic characteristics of the reactor 1 improve.

[0245] [Table 3]

[0246]

[0247] As shown in Table 3, the total loss of specimen No. 23 in which the core 3 is made of a composite material decreases. On the other hand, the total loss of specimen No. 21 in which the core 3 is made of a powder-compacted body increases. From the viewpoint of reducing the total loss, when inner square recesses 4 and 5 are provided in the side cores 33 and 34, it is preferable that the side cores 33 and 34 are composite materials.

[0248] Explanation of reference numerals

[0249] 1 Reactor

[0250] 2 Coil

[0251] 21 First winding portion, 2a, 2b Ends

[0252] 211 First end face, 212 Second end face

[0253] 213 First side face, 214 Second side face

[0254] 3 Core

[0255] 3g Gap portion

[0256] 3A First chip, 3B Second chip, 3C Third chip, 3D Fourth chip

[0257] 30 Intermediate core, 31 First end core, 32 Second end core

[0258] 33 First side core, 34 Second side core

[0259] 330, 340 Inner square surface

[0260] 4 Inner square recess

[0261] 40 Bottom surface, 41, 42 Inner wall surface

[0262] 5 Inner square recess

[0263] 1100 Power conversion device

[0264] 1110 Converter, 1111 Switching element, 1112 Drive circuit

[0265] 1115 Reactor, 1120 Inverter

[0266] 1150 Converter for power supply device, 1160 Converter for auxiliary machine power supply

[0267] 1200 Vehicle

[0268] 1210 Main battery, 1220 Motor, 1230 Auxiliary battery

[0269] 1240 Auxiliary machines, 1250 Wheels

[0270] 1300 Engine

[0271] D1 Depth

[0272] H Height

[0273] L, T0, T1, T2, T3, T4, T12 Length

[0274] W, W1 Width

Claims

1. A reactor, comprising a coil and a magnetic core, The coil has a first winding portion, The magnetic core includes: An intermediate core disposed inside the first winding portion; A first end core facing the first end face of the first winding portion; A second end core facing the second end face of the first winding portion; A first side core disposed outside the first side face of the first winding portion, connecting the first end core and the second end core; And A second side core disposed outside the second side face of the first winding portion, connecting the first end core and the second end core, At least one of the first side core and the second side core has an inner concave portion provided on the inner surface, and the inner surface is a surface facing the first winding portion in the Y direction. When looking down at the magnetic core from the Z direction, at least a part of the inner concave portion overlaps with the range of the length of the first winding portion in the X direction. When looking down at the magnetic core from the Z direction, the width of the inner concave portion in the X direction is 43% or more and 54% or less of the length of the intermediate core in the X direction, and the depth of the inner concave portion in the Y direction is 27% or more and 36% or less of the length of the side core having the inner concave portion in the Y direction. The X direction is the direction along the axial direction of the intermediate core. The Y direction is the direction in which the intermediate core, the first side core, and the second side core are arranged side by side. The Z direction is the direction orthogonal to the X direction and the Y direction.

2. The reactor according to claim 1, wherein The first side core and the second side core each have the inner concave portion.

3. The reactor according to claim 1 or claim 2, wherein When looking down at the magnetic core from the Z direction, the inner concave portion is formed within the range of the length of the first winding portion in the X direction.

4. The reactor according to claim 1 or claim 2, wherein The inner concave portion is a groove shape extending along the Z direction.

5. The reactor according to claim 4, wherein The cross-sectional shape orthogonal to the Z direction in the inner concave portion is a rectangle.

6. The reactor according to claim 1 or claim 2, wherein The first side core and the second side core are formed bodies of a composite material in which soft magnetic powder is dispersed in resin.

7. A converter, wherein It includes the reactor according to any one of claims 1 to 6.

8. A power conversion device, wherein It includes the converter according to claim 7.

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