Reactors, converters, and power conversion devices

Abstract

To provide a reactor with which a portion of a mold member integrating a coil with a magnetic core easily fills the inside of a winding part.SOLUTION: A reactor comprises: a coil including a winding part; a magnetic core including an inner core part disposed inside the winding part; a first spacer disposed between the winding part and the inner core part; and a mold member integrating the coil with the magnetic core. The inner core part has a square pole shape and is composed of: a first core having a first end face; and a second core having a second end face disposed spaced apart from the first end face. The first spacer has a trough shape having an inner peripheral surface opposed to three outer peripheral surfaces of the inner core part. A part of the mold member is disposed at a first gap between the winding part and a portion which the inner peripheral surface of the inner core part does not face, and at a second gap between the first end face and the second end face.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Patent Literature 1 discloses a reactor including a coil having a wound portion and a magnetic core. The magnetic core includes a middle core portion disposed inside the wound portion. The middle core portion is composed of a first middle core piece and a second middle core piece. Inside the wound portion, the end face of the first middle core piece and the end face of the second middle core piece are arranged with a gap therebetween.

[0003] The reactor further includes a mold resin portion covering at least a part of the magnetic core. The mold resin portion corresponds to the mold member in the present specification. When forming the mold resin portion, the resin constituting the mold resin portion enters the gap between the wound portion and the inner core portion (hereinafter referred to as gap A) from the position of the end face of the wound portion, and reaches the gap between the end face of the first middle core piece and the end face of the second middle core piece (hereinafter referred to as gap B). The mold resin portion that has entered gap B functions as a resin gap that adjusts the magnetic properties of the magnetic core. A resin gap constituted by a part of the mold resin portion can be regarded as a part of the inner core portion. [Prior Art Documents] [Patent Literature]

[0004] [Patent Literature 1] Japanese Unexamined Patent Publication No. 2021-141123 [Summary of Invention] [Problems to be Solved by the Invention]

[0005] To miniaturize the reactor and improve its heat dissipation, there is a need to reduce the gap A between the winding section and the middle core section, and to reduce the gap B between the end face of the first middle core piece and the end face of the second middle core piece inside the winding section. In this case, it becomes difficult to fill gap A with resin, and because gaps A and B are perpendicular, it is difficult for resin to pass through gap A to fill gap B. If the resin filling of gap B is insufficient and a void is formed in gap B, the heat dissipation of the reactor may decrease, or the function of the resin gap may deteriorate. If the resin pressure is too high when molding the coil and magnetic core from the outside in order to sufficiently fill gap B with resin, the magnetic core may crack due to the pressure of the resin.

[0006] One of the purposes of this disclosure is to provide a reactor in which a portion of the molded member that integrates the coil and the magnetic core is easily filled inside the winding portion. [Means for solving the problem]

[0007] The reactor in this disclosure is A coil having a winding section, A magnetic core having an inner core portion disposed inside the winding portion and an outer core portion disposed outside the winding portion, A first spacer is disposed between the winding portion and the inner core portion, The system comprises a molded member that integrates the coil and the magnetic core, The inner core portion has a rectangular prism shape and is composed of a first core portion having a first end face that is positioned inside the winding portion and a second core portion having a second end face that is positioned at a distance from the first end face. The first spacer has a trough shape with an inner surface facing the three outer surfaces of the inner core portion, A portion of the mold member is positioned in the first gap between the portion of the inner core where the inner circumferential surfaces are not facing each other and the winding portion, and in the second gap between the first end face and the second end face. [Effects of the Invention]

[0008] The reactor of this disclosure is a reactor in which a portion of the molded member that integrates the coil and the magnetic core is sufficiently filled inside the winding portion. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic perspective view of the reactor described in Embodiment 1. [Figure 2] Figure 2 is an exploded perspective view of the reactor, excluding the molded components. [Figure 3] Figure 3 is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] Figure 4 is a cross-sectional view taken along line IV-IV of Figure 4. [Figure 5] Figure 5 is a schematic diagram showing the power supply system of a hybrid vehicle. [Figure 6] Figure 6 is a circuit diagram showing an example of a power conversion device equipped with a converter. [Modes for carrying out the invention]

[0010] [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described.

[0011] <1> The reactor according to this embodiment is A coil having a winding section, A magnetic core having an inner core portion disposed inside the winding portion and an outer core portion disposed outside the winding portion, A first spacer is disposed between the winding portion and the inner core portion, The system comprises a molded member that integrates the coil and the magnetic core, The inner core portion has a rectangular prism shape and is composed of a first core portion having a first end face that is positioned inside the winding portion and a second core portion having a second end face that is positioned at a distance from the first end face. The first spacer has a trough shape with an inner surface facing the three outer surfaces of the inner core portion, A part of the molding member is disposed in a first gap between a portion of the inner core where the inner peripheral surfaces do not face each other and the winding portion, and a second gap between the first end face and the second end face.

[0012] In the reactor according to the embodiment, a first spacer having a gutter shape is disposed in a gap between a quadrangular prism-shaped inner core portion and a winding portion, and the first spacer blocks a part of the gap. The gap narrowed by the first spacer is a first gap through which a resin constituting the molding member passes when the molding member is formed. In the first gap formed of the narrowed gap, the filling pressure of the resin is easily maintained at a high level. Therefore, the resin is easily filled into the first gap without increasing the pressure of the resin when molding the coil and the magnetic core from the outside. In addition, the high-pressure resin that has passed through the first gap easily enters the second gap formed between the first end face of the first core portion constituting the inner core portion and the second end face of the second core portion. Since the pressure of the resin does not become excessively high when molding the coil and the magnetic core from the outside, damage to the magnetic core caused by the resin pressure is suppressed. Further, in the reactor according to the embodiment, the first gap and the second gap are sufficiently filled with the resin, and defects such as voids are less likely to occur in the molding member disposed in the second gap. A part of the molding member with few defects disposed in the second gap exhibits desired characteristics as a resin gap.

[0013] The molding member functions as a heat transfer path that conducts heat from the inside to the outside of the winding portion. If there are few defects such as voids in the molding member inside the winding portion, the function of the molding member as a heat transfer path is less likely to decrease due to the defects.

[0014] By securing the electrical insulation distance between the winding portion and the inner core portion by a part of the molding member and the first spacer, the distance between the winding portion and the inner core portion can be reduced. As a result, the winding portion can be reduced in size. Therefore, the reactor according to the embodiment is compact.

[0015] <2>In the reactor described in the above <1>, The first spacer may cover 45% or more of the circumferential length of the inner core portion.

[0016] The circumferential length of the inner core portion refers to the length of the contour line when the inner core portion is cut along a cross section orthogonal to the axis of the inner core portion. If the first spacer covers 45% or more of the circumferential length of the inner core portion, the filling pressure of the resin in the first gap is maintained at a high level, and the resin can easily spread sufficiently into the second gap.

[0017] <3>In the reactor according to the above <1> or <2>, comprising a second spacer disposed between the end face of the wound portion and the outer core portion, The first spacer and the second spacer may be an integrated component.

[0018] The second spacer can sufficiently secure an electrical insulation distance between the end face of the wound portion and the outer core portion. If the first spacer and the second spacer are an integrated component, the position of the first spacer inside the wound portion is easily fixed when manufacturing the reactor. Accordingly, when the resin constituting the mold member is filled into the inside of the wound portion, the first spacer is less likely to move.

[0019] <4>In the reactor according to any one of the above <1> to <3>, The thickness of the first spacer may be 0.5 mm or more and 2.0 mm or less.

[0020] If the thickness of the first spacer is 0.5 mm or more, a sufficient electrical insulation distance between the wound portion and the inner core portion is secured. If the thickness of the first spacer is 2.0 mm or less, heat of the inner core portion easily dissipates to the wound portion. Accordingly, the heat dissipation performance of the reactor is improved. That the thickness of the first spacer is 2.0 mm or less means that the wound portion is small. Therefore, a reactor in which the thickness of the first spacer is 2.0 mm or less is compact in size.

[0021] <5>In the reactor according to any one of the above <1> to <4>, The width of the first gap may be 0.5 mm or more and 4.0 mm or less.

[0022] The width of the first gap is the distance between the outer surface of the inner core and the inner surface of the winding. If the width of the first gap is 0.5 mm or more, the resin constituting the molded member is more easily positioned in the first gap when forming the molded member. If the width of the first gap is 4.0 mm or less, heat from the inner core can easily escape to the winding. Therefore, the heat dissipation performance of the reactor is improved. A first gap width of 4.0 mm or less means that the winding is small. Therefore, a reactor with a first gap width of 4.0 mm or less is small.

[0023] <6> the above <1> from <5> In a reactor described in any of the following, The width of the second gap may be between 0.8 mm and 4.0 mm.

[0024] If the width of the second gap is 0.8 mm or more, the resin constituting the molded member is more easily placed in the second gap when forming the molded member. If the width of the second gap is 4.0 mm or less, magnetic flux leakage in the second gap is reduced. Therefore, losses due to leakage magnetic flux are reduced.

[0025] <7> the above <1> from <6> In a reactor described in any of the following, The magnetic core is A first core piece including a part of the outer core and the first core, The material may be configured by combining a part of the outer core portion with a second core piece that includes the second core portion.

[0026] The fact that the magnetic core is composed of two core pieces makes it easier to assemble the magnetic core into the coil when manufacturing the reactor. Therefore, the productivity of reactor production is improved.

[0027] <8> The converter according to the embodiment is as described above. <1> from <7> It comprises a reactor as described in any of the following.

[0028] The reactor according to the embodiment is compact. Therefore, the converter equipped with the reactor according to the embodiment is also compact. The reactor according to the embodiment has excellent heat dissipation. Therefore, the converter equipped with the reactor according to the embodiment operates stably.

[0029] <9> The power conversion device according to the embodiment is as described above. <8> It is equipped with the converter described.

[0030] The power conversion device equipped with the converter according to this embodiment is compact and operates stably.

[0031] [Details of the embodiments of this disclosure] Embodiments of the reactors, converters, and power converters of this disclosure will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same parts. However, the present invention is not limited to the configurations shown in the embodiments, but is intended to be limited to those shown in the claims, and all modifications within the meaning and scope of the claims are intended to be included.

[0032] <Embodiment 1> The reactor 1 in this example, shown in Figures 1 and 2, comprises a coil 2, a magnetic core 3, a first spacer 4, and a molded member 5. One of the features of this example is the arrangement and shape of the first spacer 4, and the formation state of the molded member 5. The details of the reactor 1 in this example will be described below.

[0033] ≪Coil≫ Coil 2 has at least one winding section 21, as shown in Figure 2. Coil 2 in this example comprises one winding section 21. The winding section 21 is constructed by winding a wire spirally. Known windings can be used for the winding. The winding in this embodiment is a coated flat wire made of a conductor wire with an insulating coating. The conductor wire is, for example, a copper flat wire. The insulating coating is, for example, enamel. The winding section 21 in this example is an edgewise coil made by winding a coated flat wire edgewise.

[0034] The winding portion 21 has a rectangular tubular shape. That is, the end face shape of the winding portion 21 in this example is rectangular frame-shaped. The corners of the winding portion 21 in this example are rounded. Because the winding portion 21 has a rectangular tubular shape, the contact area between the winding portion 21 and the installation target tends to be larger compared to when the winding portion is cylindrical with the same cross-sectional area. Therefore, the reactor 1 can easily dissipate heat to the installation target via the winding portion 21. In addition, the installation state of the winding portion 21 relative to the installation target tends to be more stable.

[0035] Here, the directions in reactor 1 are defined with respect to coil 2. First, the direction from the first end to the second end of winding section 21 along the axis of winding section 21 is the X1 direction. The direction from the first side surface to the second side surface of winding section 21 is the Y1 direction. The direction from the bottom surface to the top surface of winding section 21 is the Z1 direction. The X1, Y1, and Z1 directions are orthogonal to each other. The X2, Y2, and Z2 directions are the opposite directions of the X1, Y1, and Z1 directions, respectively.

[0036] In this example, the end 22 of the winding positioned in the X1 direction of the winding section 21 is pulled out from the winding section 21 in the X1 direction. Also in this example, the end 23 of the winding section 21 positioned in the X2 direction is pulled out in the Y2 direction. The insulating coating is stripped from the ends 22 and 23, exposing the conductor wires. Terminal members (not shown) are connected to the exposed conductor wires.

[0037] Unlike this example, if there are, for example, two winding sections 21, the two winding sections 21 may be connected to independent power sources, or they may be connected to a single power source.

[0038] Magnetic Core The magnetic core 3 is a magnetic material in which a closed magnetic circuit is formed inside. The magnetic core 3 is a compacted powder body or a molded body of a composite material. The magnetic core 3 may be constructed by combining a core piece made of compacted powder and a core piece made of a molded composite material, or by covering the outer circumference of a core piece made of compacted powder with a composite material.

[0039] The compacted body is formed by pressure molding raw material powder containing soft magnetic powder. The soft magnetic powder is, for example, pure iron or an iron alloy. The iron alloy is, for example, an Fe (iron)-Si (silicon) alloy or an Fe-Ni (nickel) alloy. The raw material powder may also contain a lubricant. The soft magnetic powder content in the compacted body is, for example, more than 80% by volume, and more specifically 85% or more, when the entire compacted body is considered as 100% by volume.

[0040] A molded composite material is produced by filling a mold with a mixture of soft magnetic powder and unsolidified resin, and then solidifying the resin. In a molded composite material, the soft magnetic powder is dispersed in the resin. Examples of resins 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, and acrylonitrile butadiene styrene (ABS) resin. The resin may also be BMC (Bulk molding compound) which is an unsaturated polyester mixed with calcium carbonate or glass fibers, millable silicone rubber, or millable urethane rubber. The content of soft magnetic powder in the composite material is, for example, 30% to 80% by volume when the total volume of the composite material is considered as 100% by volume. The content of soft magnetic powder in the composite material may further be 50% or more by volume, 60% or more by volume, or 70% or more by volume.

[0041] The magnetic core 3 comprises an inner core portion 31 and an outer core portion 32. The inner core portion 31 is located inside the winding portion 21 of the coil 2 and is aligned with the axis of the winding portion 21. The number of inner core portions 31 is the same as the number of winding portions 21. In this example, there is one winding portion 21, so there is also one inner core portion 31. In this example, both ends of the portion of the magnetic core 3 that aligns with the axis of the winding portion 21 protrude from the end face of the winding portion 21. These protruding portions are also part of the inner core portion 31.

[0042] The inner core portion 31 has a rectangular prism shape. Since the winding portion 21 in this example has a rectangular tube shape, the shape of the inner core portion 31 conforms to the internal shape of the winding portion 21. This inner core portion 31 is composed of a first core portion 311 and a second core portion 312. As shown in Figure 4, a gap 8 is formed between the inner core portion 31 and the winding portion 21. Part of this gap 8 is blocked by the first spacer 4, which will be described later. Part of the mold member 5, which will be described later, is placed in the first gap 81 of the gap 8 that is not blocked by the first spacer 4.

[0043] The width W1 of the first gap 81 is, for example, 0.5 mm or more and 4.0 mm or less. If the width W1 is 0.5 mm or more, the resin constituting the molded member 5 is easily placed in the first gap 81 when forming the molded member 5. If the width W1 is 4.0 mm or less, the heat from the inner core portion 31 escapes easily to the winding portion 21. Therefore, the heat dissipation performance of the reactor 1 is improved. If the width W1 is 4.0 mm or less, the inner dimensions of the winding portion 21 can be reduced, and consequently, the outer dimensions of the winding portion 21 can be reduced. Therefore, a reactor 1 with a width W1 of 4.0 mm or less is compact. Furthermore, the width W1 may be 0.8 mm or more and 3.0 mm or less.

[0044] As shown in Figure 3, the first end face 311E of the first core portion 311 is located inside the winding portion 21. Similarly, the second end face 312E of the second core portion 312 is also located inside the winding portion 21. The first end face 311E and the second end face 312E are separated in the direction along the axis of the inner core portion 31. That is, a second gap 82 is formed between the first end face 311E and the second end face 312E. A part of the mold member 5, which will be described later, is placed in the second gap 82. The mold member 5 placed in the second gap 82 functions as a gap that adjusts the magnetic properties of the magnetic core 3.

[0045] The width W2 of the second gap 82 is, for example, 0.8 mm or more and 4.0 mm or less. If the width W2 is 0.8 mm or more, the resin constituting the molded member 5 can easily enter the second gap 82 when forming the molded member 5. If the width W2 is 4.0 mm or less, magnetic flux leakage in the second gap 82 is reduced. Therefore, losses due to leakage magnetic flux are reduced. Furthermore, the width W2 may be 1.0 mm or more and 3.0 mm or less.

[0046] The outer core portion 32 is the part of the magnetic core 3 that is located outside the winding portion 21. The shape of the outer core portion 32 is not particularly limited as long as it connects the ends of the inner core portion 31. As shown in Figure 2, the outer core portion 32 in this example is composed of an end core portion facing the end face of the winding portion 21 in the X1 direction, an end core portion facing the end face of the winding portion 21 in the X2 direction, a side core portion facing the side surface of the winding portion 21 in the Y1 direction, and a side core portion facing the side surface of the winding portion 21 in the Y2 direction. This outer core portion 32 is rectangular and annular when viewed in the Z2 direction. Unlike this example, the number of side core portions may be one. In addition, if the number of winding portions 21 and the number of inner core portions 31 are two, the outer core portion 32 is composed of, for example, an end core portion connecting the ends of the two inner core portions 31, 31 in the X1 direction, and an end core portion connecting the ends of the two inner core portions 31, 31 in the X2 direction.

[0047] The magnetic core 3 in this example is composed of a first core piece 3A and a second core piece 3B. The first core piece 3A includes the first core portion 311 of the inner core portion 31 and a part of the outer core portion 32. The first core piece 3A is roughly T-shaped when viewed in the Z2 direction. The second core piece 3B includes the second core portion 312 of the inner core portion 31 and a part of the outer core portion 32. The second core piece 3B is roughly E-shaped when viewed in the Z2 direction. The shapes of the core pieces 3A and 3B are not particularly limited. For example, both the first core piece 3A and the second core piece 3B may be roughly E-shaped when viewed in the Z2 direction. In addition, the magnetic core 3 may be composed of three or more segmented cores. When the number of winding portions 21 and the number of inner core portions 31 are two, each of the first core piece 3A and the second core piece 3B is, for example, U-shaped.

[0048] The first core piece 3A in this example is made of a compacted powder molded body. The second core piece 3B in this example is made of a composite material.

[0049] ≪First Spacer≫ The first spacer 4 is positioned between the winding portion 21 and the inner core portion 31, as shown in Figure 3. In this example, the first spacer 4 has approximately the same length as the total length along the axis of the inner core portion 31. Unlike this example, the length of the first spacer 4 in this example may be shorter than the total length of the inner core portion 31.

[0050] As shown in Figure 4, the first spacer 4 has a trough shape with an inner circumferential surface 41 that faces three of the four outer circumferential surfaces 31a, 31b, 31c, and 31d of the inner core portion 31. The outer circumferential surfaces 31a, 31b, 31c, and 31d of the inner core portion 31 are the surfaces that face the inner circumferential surface of the winding portion 21. Outer circumferential surface 31a is the surface facing the Z2 direction. Outer circumferential surface 31b is the surface facing the Y1 direction. Outer circumferential surface 31c is the surface facing the Y2 direction. Outer circumferential surface 31d is the surface facing the Z1 direction.

[0051] The inner circumferential surface 41 of the first spacer 4 covers the entire outer circumferential surface 31a, at least a portion of the outer circumferential surface 31b, and at least a portion of the outer circumferential surface 31c. In other words, the trough-shaped first spacer 4 holds down the three outer circumferential surfaces 31a, 31b, and 31c of the rectangular prism-shaped inner core portion 31. As a result, the inner core portion 31 is positioned in a predetermined location within the winding portion 21. Consequently, when the resin constituting the mold member 5 is filled into the first gap 81, the position of the inner core portion 31 is difficult to move.

[0052] As described above, the first spacer 4 has an inner circumferential surface 41 that faces the entire outer circumferential surface 31a of the inner core portion 31 and at least a portion of the outer circumferential surfaces 31b and 31c. In other words, the first spacer 4 covers more than 25% of the circumference of the inner core portion 31. To put it another way, the length of the inner circumferential surface 41 of the first spacer 4 in a cross-section perpendicular to the axis of the inner core portion 31 is more than 25% of the circumference of the inner core portion 31. On the other hand, the first spacer 4 does not cover the outer circumferential surface 31d of the inner core portion 31. Therefore, the length of the inner circumferential surface 41 of the first spacer 4 in the above cross-section is 75% or less of the circumference of the inner core portion 31. The length of the inner circumferential surface 41 of the first spacer 4 in the above cross-section may be, for example, 30% or more, 35% or more, 45% or more, or 65% or more of the circumference of the inner core portion 31. In particular, if the length of the inner circumferential surface 41 of the first spacer 4 in the above cross-section is 45% or more of the circumference of the inner core portion 31, the molded member 5 will easily fit into the second gap 82, regardless of the size of the second gap 82.

[0053] In this example, there is substantially no gap between the first spacer 4 and the inner core portion 31, and between the first spacer 4 and the winding portion 21. In this specification, "substantially no gap between the two members" means that the gap between the two members is 0.1 mm or less. Unlike this example, gaps may be formed between the first spacer 4 and the inner core portion 31, and between the first spacer 4 and the winding portion 21. In that case, the gaps may be, for example, 0.5 mm or less.

[0054] The thickness t of the first spacer 4 is, for example, 0.5 mm or more and 2.0 mm or less. If the thickness t is 0.5 mm or more, sufficient electrical insulation distance is ensured between the winding portion 21 and the inner core portion 31. If the thickness t is 2.0 mm or less, heat from the inner core portion 31 can easily escape to the winding portion 21. Therefore, the heat dissipation performance of the reactor 1 is improved. If the thickness t is 2.0 mm or less, the inner dimensions of the winding portion 21 can be reduced, and consequently, the outer dimensions of the winding portion 21 can be reduced. Therefore, a reactor 1 with a thickness t of 2.0 mm or less is compact. The thickness t may also be 0.8 mm or more and 2.0 mm or less.

[0055] The first spacer 4 is made of an insulating material. This material may be, for example, PPS resin, PTFE resin, LCP, PA resin, PBT resin, or ABS resin. Alternatively, the material of the first spacer 4 may be a thermosetting resin such as an unsaturated polyester resin, epoxy resin, urethane resin, or silicone resin. These resins may contain ceramic fillers. The ceramic fillers may be, for example, non-magnetic powders such as alumina or silica.

[0056] In this example, the first spacer 4 is integrated with the second spacer 6, which will be described later. In this case, the material of the second spacer 6 is the same as the material of the first spacer 4. The configuration of the second spacer 6 will be described later.

[0057] ≪Molded components≫ As shown in Figure 1, the molded member 5 integrates the coil 2 and the magnetic core 3 shown in Figure 2. The molded member 5 covers at least a portion of the outer surface of the coil 2 and at least a portion of the outer surface of the magnetic core 3. In this example, a portion of the winding portion 21 of the coil 2 is exposed from the molded member 5. The portion of the winding portion 21 exposed from the molded member 5 contributes to improving the heat dissipation of the reactor 1.

[0058] The mold member 5 is made of a thermoplastic resin such as PPS resin, PTFE resin, LCP, PA resin, PBT resin, or ABS resin. Alternatively, the mold member 5 may be made of a thermosetting resin such as an unsaturated polyester resin, epoxy resin, urethane resin, or silicone resin. The inclusion of ceramic fillers in these resins improves the heat dissipation of the mold member 5. The ceramic fillers are, for example, non-magnetic powders such as alumina or silica.

[0059] A portion of the molded member 5 is positioned in the first gap 81 and the second gap 82, as shown in Figure 3. When forming the molded member 5, the assembly of the coil 2 and the magnetic core 3 is placed in a mold, and the resin constituting the molded member 5 is filled into the mold. The resin is filled into the interior of the winding portion 21 from the first gap 81 at the end of the winding portion 21, as shown by the dashed arrow in Figure 3. Furthermore, the resin is filled from the first gap 81 into the second gap 82, as shown by the downward dashed arrow.

[0060] ≪Second Spacer≫ In this example, reactor 1 further includes two second spacers 6 and 7, as shown in Figure 2.

[0061] The second spacers 6 and 7 are frame-shaped members having through holes 60 and 70. The second spacers 6 and 7 are positioned between the end face of the winding portion 21 and the end core portion of the outer core portion 32. The second spacers 6 and 7 ensure electrical insulation between the winding portion 21 and the outer core portion 32. The second spacers 6 and 7 are made of a material that can be used for the first spacer 4. The through holes 60 and 70 are larger than the cross-section of the inner core portion 31 and smaller than the inner circumference of the winding portion 21. The inner core portion 31 passes through the through holes 60 and 70.

[0062] The second spacers 6 and 7 are provided with slots 61 and 71 through which their ends 22 and 23 pass. Slot 61 has a hole extending in the X1 direction. The position of the second spacer 6 relative to the coil 2 is determined by passing the end 22 through slot 61 of the second spacer 6. Slot 71 has a hole extending in the Y2 direction. The position of the second spacer 7 relative to the coil 2 is determined by passing the end 23 through slot 71 of the second spacer 7.

[0063] The inner circumferential surfaces of the through holes 60 and 70 of the second spacers 6 and 7 are provided with pressing portions 62 and 72 that protrude inward from the through holes 60 and 70. As shown in Figure 3, when the second spacers 6 and 7 are positioned between the winding portion 21 and the outer core portion 32, these pressing portions 62 and 72 press against the outer circumferential surface 31d of the inner core portion 31. In other words, the inner core portion 31 is supported from four directions by the inner circumferential surface 41 of the first spacer 4 and the pressing portions 62 and 72 of the second spacers 6 and 7. Thus, the position of the inner core portion 31 inside the winding portion 21 is determined.

[0064] In this example, the second spacer 6 and the first spacer 4 are a single unit. The end of the first spacer 4 fits into the through hole 70 of the second spacer 7. This fitting mechanically connects the first spacer 4, the second spacer 6, and the second spacer 7, determining their relative positions. In this case, when manufacturing the reactor 1, the position of the first spacer 4 inside the winding section 21 is easily fixed. Therefore, when the resin constituting the molded member 5 is filled inside the winding section 21, the first spacer 4 is less likely to move.

[0065] Unlike this example, the first spacer 4 may be integrated with both the second spacer 6 and the second spacer 7. For example, in Figure 3, a portion of the first spacer 4 may be integrated with the second spacer 6, and the remaining portion of the first spacer 4 may be integrated with the second spacer 7. In that case, within the winding portion 21, the end face of the first spacer 4 integrated with the second spacer 6 and the end face of the first spacer 4 integrated with the second spacer 7 will be brought into contact.

[0066] ≪Method for manufacturing reactors≫ When manufacturing the reactor 1 described above, an assembly is created by combining the coil 2, magnetic core 3, first spacer 4, and second spacers 6 and 7, and this assembly is placed in a mold. Next, the mold is filled with resin, which will be the material for the molded member 5. As shown by the dashed arrow in Figure 3, the resin enters the first gap 81 from the end of the winding portion 21. At this time, the resin pressure is maintained at a high level in the first gap 81, which is formed by narrowing the gap 8 with the first spacer 4. Therefore, the resin is easily filled into the first gap 81 even without increasing the pressure of the resin being filled into the mold. The resin, with its pressure maintained at a high level, enters the second gap 82 with force from the first gap 81. As a result, the resin spreads throughout the second gap 82, and defects such as voids are less likely to form in the molded member 5 formed in the second gap 82 as the resin solidifies. The molded member 5 is connected from the outside of the winding portion 21 through the first gap 81 to the second gap 82. Furthermore, the mold member 5 positioned in the second gap 82 adheres the first core portion 311 and the second core portion 312 together. Thus, the mold member 5 creates a reactor 1 in which the coil 2 and the magnetic core 3 are firmly integrated.

[0067] The mold member 5 positioned in the second gap 82 functions as a heat transfer path, releasing heat from the inner core 31 to the outside. The mold member 5, positioned throughout the second gap 82, improves the heat dissipation of the reactor 1. In particular, in the reactor 1 of this example, defects such as voids are less likely to form in the mold member 5 positioned in the second gap 82 inside the winding portion 21. Therefore, a decrease in heat conductivity from the inside to the outside of the inner core 31 due to defects, and a decrease in the function of the mold member 5 as a resin gap can be suppressed.

[0068] In this example, when forming the molded member 5, the position of the inner core portion 31 within the winding portion 21 is determined by the first spacer 4. Therefore, the distance between the inner core portion 31 and the winding portion 21 can be reduced, that is, the size of the winding portion 21 can be reduced. Consequently, the reactor 1 in this example is small and lightweight.

[0069] <Embodiment 2> <<Converters / Power Conversion Devices>> The reactor 1 according to the above embodiment can be used for applications that satisfy the following energizing conditions. For example, the energizing conditions are that the maximum DC current is approximately 100A to 1000A, the average voltage is approximately 100V to 1000V, and the operating frequency is approximately 5kHz to 100kHz. The reactor 1 according to the embodiment is typically used as a component of a converter mounted on a vehicle such as an electric vehicle or a hybrid vehicle, or as a component of a power conversion device equipped with such a converter.

[0070] A vehicle 1200, such as a hybrid or electric vehicle, includes a main battery 1210, a power converter 1100 connected to the main battery 1210, and a motor 1220 that is driven by power supplied from the main battery 1210 and used for propulsion, as shown in Figure 5. The motor 1220 is typically a three-phase AC motor, which drives the wheels 1250 during driving and functions as a generator during regenerative braking. In the case of a hybrid vehicle, the vehicle 1200 is equipped with an engine 1300 in addition to the motor 1220. In Figure 5, the charging point of the vehicle 1200 is an inlet, but it may also be equipped with a plug.

[0071] The power converter 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110 that performs mutual conversion between DC and AC. In this example, the converter 1110 boosts the input voltage of the main battery 1210, which is approximately 200V to 300V, to approximately 400V to 700V when the vehicle 1200 is running, and supplies power to the inverter 1120. During regeneration, the converter 1110 steps down the input voltage output from the motor 1220 via the inverter 1120 to a DC voltage suitable for the main battery 1210, thereby charging the main battery 1210. The input voltage is a DC voltage. When the vehicle 1200 is running, the inverter 1120 converts the DC voltage boosted by the converter 1110 into a predetermined AC voltage and supplies power to the motor 1220. During regeneration, it converts the AC output from the motor 1220 into DC voltage and outputs it to the converter 1110.

[0072] As shown in Figure 6, the converter 1110 comprises a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115, and converts the input voltage by repeatedly switching ON / OFF. In this case, the input voltage conversion is step-up or step-down. Power devices such as field-effect transistors and insulated-gate bipolar transistors are used as switching elements 1111. The reactor 1115 utilizes the property of a coil that tries to oppose changes in the current that is about to flow through the circuit, and has the function of smoothing the change when the current tries to increase or decrease due to the switching operation. The reactor 1115 is provided as reactor 1 according to the embodiment.

[0073] Vehicle 1200 includes, in addition to converter 1110, a power supply device converter 1150 connected to the main battery 1210, and an auxiliary power converter 1160 connected to the main battery 1210 and a sub-battery 1230 which serves as a power source for auxiliary equipment 1240, and which converts the high voltage of the main battery 1210 to low voltage. Converter 1110 typically performs DC-DC conversion, while the power supply device converter 1150 and the auxiliary power converter 1160 perform AC-DC conversion. Some power supply device converters 1150 also perform DC-DC conversion. The reactors of the power supply device converter 1150 and the auxiliary power converter 1160 have a configuration similar to reactor 1, etc., according to the embodiment, and reactors with appropriately changed size and shape can be used. Furthermore, reactor 1, etc., according to the embodiment can also be used for converters that convert input power, such as converters that only perform boosting or converters that only perform step-down.

[0074] <Example Test> In this test, the effect of the first spacer 4 on the resin filling state of the second gap 82 was investigated using Moldex3D from JSOL Corporation. Moldex3D is resin flow analysis software.

[0075] The dimensions of the main parts of the sample examined are as follows: Width W1 is the width of the first gap 81. Width W2 is the width of the second gap 82. The height ratio is the ratio to which the first spacer 4 covers the outer surfaces 31b and 31c of the inner core 31, when the length of the inner core 31 in the Z1 direction is taken as 100%. The coverage ratio is the ratio to which the first spacer 4 covers the inner core 31 in a cross-section perpendicular to the axis of the inner core 31, when the circumference of the inner core 31 is taken as 100%. Sample 1: Width W1 = 2.0 mm, Width W2 = 2.0 mm, Height ratio = 80%, Coverage ratio = 65% Sample 2: Width W1 = 2.0 mm, Width W2 = 2.0 mm, Height ratio = 40%, Coverage ratio = 45% Sample 3: Width W1 = 2.0 mm, Width W2 = 2.0 mm, Height ratio = 20%, Coverage ratio = 35% Sample 4: Width W1 = 2.0 mm, Width W2 = 1.5 mm, Height ratio = 80%, Coverage ratio = 65% Sample 5: Width W1 = 2.0 mm, Width W2 = 1.5 mm, Height ratio = 40%, Coverage ratio = 45% Sample 6: Width W1 = 2.0 mm, Width W2 = 1.5 mm, Height ratio = 20%, Coverage ratio = 35%

[0076] In samples 1 through 5, it was found that the resin was sufficiently filled throughout the second gap 82. On the other hand, in sample 6, it was found that a portion of the second gap 82 was not filled with resin at the Z2 direction end. When the pressure difference between the inside and outside of samples 1 through 5 was examined, the pressure difference between the inside and outside of samples 1 through 3 was 0.4 MPa or less, and the pressure difference between the inside and outside of samples 4 and 5 was 2.0 MPa or less. The "pressure difference between the inside and outside" refers to the pressure difference between the resin pressure on the outer circumference of the outer core portion 32 and the resin pressure at the center of the second gap 82 in the Z1 direction. On the other hand, the pressure difference between the inside and outside of sample 6 was greater than 2.0 MPa. From these results, it was found that a pressure difference between the inside and outside of 2 MPa or less is an indicator that the resin is filled throughout the second gap 82.

[0077] The test results showed that if the first spacer 4 is large enough to cover 45% or more of the circumference of the inner core 31, the second gap 82 can be sufficiently filled with resin regardless of the thickness of the second gap 82. On the other hand, a comparison between sample 3, in which the width W2 of the second gap 82 is 2.0 mm, and sample 6, in which the width W2 of the second gap 82 is 1.5 mm, showed that, depending on the width W2 of the second gap 82, it may be possible to sufficiently fill the second gap 82 with resin even if the first spacer 4 is large enough to cover 45% or less of the circumference of the inner core 31. [Explanation of Symbols]

[0078] 1 Reactor 2 coils 21. Turning section 22,23 End 3 Magnetic core 3A First core piece 3B Second core piece 31 Inner core section 31a,31b,31c,31d Outer surface 311 First Core Section 311E First end face 312 Second Core Section 312E Second end face 32 Outer core section 4. First spacer 41 Inner surface 5. Molded component 6,7 Second spacer 60, 70 through holes 61,71 slots 62,72 Pressing part 8 gaps 81 The first gap 82 The second gap 1100 Power converter 1110 converter 1111 Switching elements 1112 Drive Circuit 1115 Reactor 1120 Inverter 1150 Converter for power supply device 1160 Auxiliary Power Converter 1200 vehicles 1210 Main Battery 1220 Motor 1230 Sub-battery 1240 Auxiliary equipment 1250 wheels 1300 engine t thickness W1, W2 width

Claims

1. A coil having a winding section, A magnetic core having an inner core portion disposed inside the winding portion and an outer core portion disposed outside the winding portion, A first spacer is disposed between the winding portion and the inner core portion, The system comprises a molded member that integrates the coil and the magnetic core, The inner core portion has a rectangular prism shape and is composed of a first core portion having a first end face that is positioned inside the winding portion and a second core portion having a second end face that is positioned at a distance from the first end face. The first spacer has a trough shape with an inner circumferential surface facing the three outer circumferential surfaces of the inner core portion, and a length that extends along the entire length of the winding portion. A portion of the mold member is positioned in the first gap between the portion of the inner core where the inner circumferential surfaces are not facing each other and the winding portion, and in the second gap between the first end face and the second end face. Reactor.

2. The reactor according to claim 1, wherein the first spacer covers 45% or more of the circumference of the inner core portion.

3. A second spacer is provided between the end face of the winding portion and the outer core portion, The reactor according to claim 1 or claim 2, wherein the first spacer and the second spacer are a single integrated unit.

4. The reactor according to claim 1 or claim 2, wherein the thickness of the first spacer is 0.5 mm or more and 2.0 mm or less.

5. The reactor according to claim 1 or claim 2, wherein the width of the first gap is 0.5 mm or more and 4.0 mm or less.

6. The reactor according to claim 1 or claim 2, wherein the width of the second gap is 0.8 mm or more and 4.0 mm or less.

7. The magnetic core is A first core piece including a part of the outer core and the first core, The reactor according to claim 1 or claim 2, comprising a combination of a part of the outer core and a second core piece including the second core.

8. A reactor comprising the reactor according to claim 1 or claim 2, converter.

9. A converter comprising the converter described in claim 8, Power converter.

Images