Reactors, segmentation units, converters, and power conversion devices

Abstract

The present invention provides a reactor equipped with a magnetic core that can suppress the increase in iron loss and leakage flux. [Solution] A reactor 1 comprising a coil 2 having winding sections 21, 22 and a magnetic core 3, wherein the magnetic core 3 has a plurality of segmented pieces 3A, 3B, ... including a first core piece 5 and a second core piece 6, and the first core piece 5 is made of a composite material including resin and soft magnetic powder dispersed in the resin, and comprises a first portion 51 that extends in a direction perpendicular to the axial direction of the winding sections 21, 22 and is positioned facing the end faces of the winding sections 21, 22, and a second portion 52 that extends axially from the first portion 51, wherein the first portion 51 and the second portion 52 are formed in a continuous manner without joints, and the first relative permeability of the first portion 51 with respect to the magnetic flux along the extension direction of the first portion 51 is different from the second relative permeability of the second portion 52 with respect to the magnetic flux along the extension direction of the second portion 52.

Description

Technical Field

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

Background Art

[0002] A reactor is included in a component of a converter provided in a hybrid vehicle or the like. For example, the reactors described in Patent Document 1 and Patent Document 2 include a coil and a magnetic core. The coil includes a wound portion formed by winding a winding. The number of wound portions may be one or more.

[0003] The magnetic core is formed by combining a plurality of split pieces. The split piece is, for example, a compacted body formed by compacting soft magnetic powder, or a molded body of a composite material in which soft magnetic powder is dispersed in a resin. The molded body of the composite material can easily achieve desired magnetic characteristics by changing the mixing ratio of the soft magnetic powder and the resin. The molded body of the composite material can reduce iron loss in the use of the reactor at high frequencies.

Prior Art Documents

Patent Documents

[0004]

Patent Document

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, reactors have tended to be used in high-frequency and high-current applications. In reactors with segmented sections made from compacted powder, iron loss may increase with increasing frequency. While segmented sections made from composite materials exhibit lower iron loss, leakage flux tends to increase. Therefore, there is a need for reactors with segmented sections that suppress increases in both iron loss and leakage flux. Such reactors possess excellent magnetic properties, particularly in high-frequency and high-current applications.

[0006] One objective of this disclosure is to provide a reactor equipped with a magnetic core that can suppress the increase in iron loss and leakage flux. Another objective of this disclosure is to provide a segmented piece that can suppress the increase in iron loss and leakage flux. Furthermore, one objective of this disclosure is to provide a converter and a power conversion device equipped with a reactor with excellent magnetic properties. [Means for solving the problem]

[0007] The reactor in this disclosure is A reactor comprising a coil having a wound portion and a magnetic core, The magnetic core has a plurality of segmented pieces, including a first core piece. The first core piece is made of a composite material comprising a resin and soft magnetic powder dispersed in the resin. A first portion extending in a direction perpendicular to the axial direction of the winding portion and positioned facing the end face of the winding portion, It comprises a second portion extending from the first portion in the axial direction, The first part and the second part are formed in a continuous manner without any joint. The first relative permeability of the first part with respect to the magnetic flux along the extension direction of the first part is different from the second relative permeability of the second part with respect to the magnetic flux along the extension direction of the second part.

[0008] The fragments of this disclosure are A segmented piece that constitutes part of the magnetic core of the reactor, It is composed of a composite material comprising a resin and soft magnetic powder dispersed in the resin. Part one, It comprises a second portion extending in a direction perpendicular to the extension direction of the first portion, The first part and the second part are formed in a continuous manner without any joint. The first relative permeability of the first part with respect to the magnetic flux along the extension direction of the first part is different from the second relative permeability of the second part with respect to the magnetic flux along the extension direction of the second part.

[0009] The converter of this disclosure comprises the reactor of this disclosure.

[0010] The power conversion device of this disclosure comprises a converter of this disclosure. [Effects of the Invention]

[0011] In the reactor and segmented parts of this disclosure, the increase in iron loss and leakage flux is suppressed. Furthermore, the converter and power converter of this disclosure operate stably. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic top view of the reactor described in Embodiment 1. [Figure 2] Figure 2 is a photograph of the XY cross-section of the first part of the reactor shown in Figure 1. [Figure 3] Figure 3 is a schematic top view of the reactor described in Embodiment 2. [Figure 4] Figure 4 is a schematic top view of the reactor described in Embodiment 3. [Figure 5] Figure 5 is a schematic top view of the reactor described in Embodiment 4. [Figure 6] Figure 6 is a schematic diagram showing the power supply system of a hybrid vehicle. [Figure 7] Figure 7 is a schematic circuit diagram showing an example of a power conversion device equipped with a converter. [Embodiments for Carrying Out the Invention]

[0013] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0014] <1> The reactor according to the embodiment is a reactor including a coil having a winding portion and a magnetic core, where the magnetic core has a plurality of divided pieces including a first core piece, the first core piece is composed of a composite material including a resin and soft magnetic powder dispersed in the resin, a first portion extending in a direction orthogonal to the axial direction of the winding portion and disposed at a position facing the end face of the winding portion, and a second portion extending from the first portion in the axial direction, where the first portion and the second portion are formed continuously without a joint, [[ID=]] and a first relative permeability of the first portion with respect to magnetic flux along the extending direction of the first portion is different from a second relative permeability of the second portion with respect to magnetic flux along the extending direction of the second portion.

[0015] In the first core piece composed of the composite material, the iron loss is less likely to increase compared to the core piece composed of the compacted powder body. This is because in the composite material, the resin enters between the particles of the soft magnetic powder, making it difficult for the particles to contact each other, thus suppressing the increase in iron loss. In the first core piece in the above configuration, there is anisotropy in the ease of magnetic flux passing through the first portion and the second portion. Specifically, the extending direction of the first portion and the extending direction of the second portion are orthogonal to each other, and either the first relative permeability along the extending direction of the first portion or the second relative permeability along the extending direction of the second portion is higher than the other. The location with a high relative permeability suppresses the increase in leakage magnetic flux in the first core piece. A reactor provided with such a first core piece exhibits excellent magnetic characteristics particularly at high frequencies and high currents.

[0016] Because resin is interposed between each particle of soft magnetic powder within the first core piece, the first core piece can be considered to have a magnetic gap. Therefore, the magnetic core containing this first core piece is resistant to magnetic saturation. A reactor equipped with a first core piece that is resistant to magnetic saturation operates stably, especially at high frequencies and high currents.

[0017] <2> the above <1> In the reactor described, The first relative permeability may be higher than the second relative permeability.

[0018] The first portion, having a first relative permeability, is located outside the coil winding. Leakage flux in the first portion may adversely affect other electronic equipment located near the reactor. A higher first relative permeability reduces the leakage flux in the first portion, thereby reducing adverse effects on other electronic equipment.

[0019] <3> the above <1> or <2> In the reactor described, The first core piece has an E-shape, comprising a base and three legs extending from the base. The base is the first part, Each of the three legs may also be the second part.

[0020] In the above configuration, the number of divisions in the magnetic core is small. The core pieces that are combined with the E-shaped core piece are E-shaped, T-shaped, or I-shaped core pieces. In this case, the number of divisions in the magnetic core is 2.

[0021] <4> the above <1> from <3> In a reactor described in any of the following, The magnetic core may consist of the first core piece and a second core piece having the same configuration as the first core piece.

[0022] "Same composition" means that the shape, dimensions, material, and structure are all substantially the same. <4> In this configuration, the first and second core pieces are manufactured using the same composite material and the same mold. Consequently, the productivity of the magnetic core is improved, as is the productivity of the reactor containing the magnetic core.

[0023] The first and second core pieces, having the same configuration, are, for example, E-shaped core pieces. Alternatively, the first and second core pieces may be, for example, F-shaped core pieces.

[0024] <5> The divided piece according to this embodiment is A segmented piece that constitutes part of the magnetic core of the reactor, It is composed of a composite material comprising a resin and soft magnetic powder dispersed in the resin. Part one, It comprises a second portion extending in a direction perpendicular to the extension direction of the first portion, The first part and the second part are formed in a continuous manner without any joint. The first relative permeability of the first part with respect to the magnetic flux along the extension direction of the first part is different from the second relative permeability of the second part with respect to the magnetic flux along the extension direction of the second part.

[0025] In segmented pieces made of composite materials, iron loss is less likely to increase compared to segmented pieces made of compacted powder. This is because the resin easily penetrates between the individual particles of the soft magnetic powder. In the segmented piece with the above configuration, either the first part or the second part has a higher relative permeability than the other. This area with higher relative permeability suppresses the increase in leakage flux in the segmented piece.

[0026] <6> The converter according to the embodiment is as described above. <1> from <5> It is equipped with a reactor as described in any of the following.

[0027] The above converter includes a reactor of an embodiment that possesses excellent magnetic properties and is resistant to magnetic saturation. Therefore, the converter exhibits stable and excellent performance.

[0028] <7> The power conversion device according to the embodiment is as described above. <6> It is equipped with the converter described.

[0029] The above power conversion device is equipped with a converter that exhibits stable and excellent performance. Therefore, the above power conversion device exhibits stable and excellent performance.

[0030] [Details of the embodiments of this disclosure] Embodiments 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 equivalence to the claims are intended to be included.

[0031] <Embodiment 1> The reactor 1 in this example, shown in Figure 1, is composed of a coil 2 and a magnetic core 3. One of the features of this reactor 1 is that the magnetic core 3 includes a first core piece 5 made of a molded composite material, and the relative permeability is partially changed in this first core piece 5. The various components of the reactor 1 will be described in detail below.

[0032] ≪Coil≫ Coil 2 has at least one winding section 21, 22. Coil 2 in this example comprises winding section 21 and winding section 22. Winding sections 21, 22 are constructed by winding a wire spirally. Known windings can be used for the wire. The winding in this embodiment is a coated flat wire made of a conductor wire having an insulating coating. The conductor wire is, for example, a copper flat wire. The insulating coating is, for example, enamel. The winding sections 21, 22 in this example are edgewise coils formed by winding coated flat wires edgewise.

[0033] The winding sections 21 and 22 are rectangular cylindrical in shape. That is, the end faces of the winding sections 21 and 22 in this example are rectangular frame-shaped. The corners of the winding sections 21 and 22 in this example are rounded. Because the winding sections 21 and 22 are rectangular cylindrical in shape, the contact area between the winding sections 21 and 22 and the installation target tends to be larger compared to when the winding sections are cylindrical with the same cross-sectional area. Therefore, the reactor 1 can easily dissipate heat to the installation target via the winding sections 21 and 22. In addition, the installation state of the winding sections 21 and 22 relative to the installation target tends to be more stable.

[0034] The ends of the winding sections 21 and 22 (not shown) are extended toward the outer circumference of the winding sections 21 and 22. At the ends of the winding sections 21 and 22, the insulating coating is stripped, exposing the conductor wires. Terminal members (not shown) are connected to the exposed conductor wires. In this example, winding sections 21 and 22 are each connected to independent power sources. Unlike this example, winding sections 21 and 22 may be connected to a single power source.

[0035] Magnetic Core The magnetic core 3 comprises a middle core portion 30, a first end core portion 31, a second end core portion 32, a first side core portion 33, and a second side core portion 34. In this example, the magnetic core 3 has an '8' shape formed by two connected ring shapes. In Figure 1, the boundaries of each core portion are shown by dashed lines. The middle core portion 30 is sandwiched between the first side core portion 33 and the second side core portion 34. The first end core portion 31 faces the first end face of the winding portions 21 and 22, i.e., the right-hand end face of the paper. The second end core portion 32 faces the second end face of the winding portions 21 and 22, i.e., the left-hand end face of the paper. The first side core portion 33 is located inside the winding portion 21. The second side core portion 34 is located inside the winding portion 22.

[0036] In this magnetic core 3, annular closed magnetic paths, indicated by thick dashed lines, are formed in the middle core portion 30, the first end core portion 31, the first side core portion 33, and the second end core portion 32. Furthermore, annular closed magnetic paths, indicated by thick dashed lines, are formed in the middle core portion 30, the first end core portion 31, the second side core portion 34, and the second end core portion 32.

[0037] Here, the direction in the reactor 1 is defined with respect to the magnetic core 3. First, the direction along the axial direction of the middle core portion 30 is the X direction. The direction perpendicular to the X direction, in which the middle core portion 30, the first side core portion 33, and the second side core portion 34 are arranged in parallel, is the Y direction. And the direction perpendicular to both the X and Y directions is the Z direction.

[0038] [Middle Core Section] The extension direction of the middle core portion 30, i.e., the axial direction, is along the axial direction of the winding portion 21 and the axial direction of the winding portion 22. As shown in Embodiment 3 described later, when there is only one winding portion 21, the winding portion 21 is arranged on the outer circumference of the middle core portion 30.

[0039] The shape of the middle core portion 30 is not particularly limited as long as it is a shape that allows sufficient magnetic paths to be formed inside the middle core portion 30. In this example, the middle core portion 30 is approximately rectangular parallelepiped. Two magnetic paths are formed in the middle core portion 30. Therefore, the magnetic path cross-sectional area of ​​the middle core portion 30 is larger than the magnetic path cross-sectional area of ​​the first side core portion 33 and the magnetic path cross-sectional area of ​​the second side core portion 34.

[0040] [First end core section, second end core section] The first end core portion 31 and the second end core portion 32 extend in the Y direction perpendicular to the axis of the middle core portion 30, and are larger than the width of the middle core portion 30 in the Y direction. That is, the first end core portion 31 protrudes outward in the Y direction beyond the middle core portion 30. The second end core portion 32 also protrudes outward in the Y direction beyond the middle core portion 30.

[0041] The shapes of the first end core portion 31 and the second end core portion 32 are not particularly limited as long as they are shaped in such a way that a sufficient magnetic path is formed inside each end core portion 31 and 32. In this example, the first end core portion 31 and the second end core portion 32 are approximately rectangular parallelepipeds. Of the four corners of the first end core portion 31 and the second end core portion 32 as viewed from the Z direction, the two corners that are furthest from the side core portions 33 and 34 may be rounded. If these two corners are rounded, the weight of the end core portions 31 and 32 is reduced. These two corners are places where magnetic flux has difficulty passing through. Therefore, even if these two corners are rounded, the magnetic properties of the reactor 1 are unlikely to deteriorate.

[0042] [First side core section, Second side core section] The first side core section 33 connects one end of the first end core section 31 in the extension direction to one end of the second end core section 32 in the extension direction. The axial direction of the first side core section 33 is parallel to the axial direction of the middle core section 30. The first side core section 33 is located inside the winding section 21.

[0043] The second side core section 34 connects the other end of the first end core section 31 in the extension direction to the other end of the second end core section 32 in the extension direction. The axial direction of the second side core section 34 is parallel to the axial direction of the middle core section 30. The second side core section 34 is located inside the winding section 22. In this example, the axes of the middle core section 30, the first side core section 33, and the second side core section 34 are located on the XY plane.

[0044] [size] When the reactor 1 shown in Figure 1 is for automotive use, the length L in the X direction of the magnetic core 3 is, for example, 30 mm to 150 mm, the width W in the Y direction of the magnetic core 3 is, for example, 30 mm to 150 mm, and the height in the Z direction is, for example, 15 mm to 75 mm.

[0045] The length T0 in the Y direction of the middle core portion 30 is, for example, 10 mm or more and 50 mm or less. The length T1 in the X direction of the first end core portion 31 and the length T2 in the X direction of the second end core portion 32 are, for example, 5 mm or more and 40 mm or less. Also, the length T3 in the Y direction of the first side core portion 33 and the length T4 in the Y direction of the second side core portion 34 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.

[0046] [Divided form] The magnetic core 3 is formed by combining multiple segmented pieces 3A and 3B. In this example, the number of segmented pieces 3A and 3B is two, but it may be three or more. Segmented piece 3A is a first core piece 5 made of a molded composite material, which will be described later. The first core piece 5 is a single molded body and has no seams. Segmented piece 3B is a second core piece 6 made of a molded composite material. The second core piece 6 has the same configuration as the first core piece 5.

[0047] The first core piece 5 in this example comprises a base and three legs extending from the base. The shape of the first core piece 5 as viewed from the Z direction is roughly E-shaped. As will be described later, the base and legs have different relative permeability. Therefore, the base is called the first part 51 and the legs are called the second part 52. The first part 51 corresponds to the first end core part 31. The second part 52, located in the center in the Y direction, corresponds to a part of the middle core part 30. The second part 52, located on the upper side of the paper in the Y direction, corresponds to the first side core part 33. The second part 52, located on the lower side of the paper in the Y direction, corresponds to the second side core part 34. The second part 52 corresponding to the middle core part 30 has a first end face 3a parallel to the YZ plane.

[0048] In this example, the second core piece 6 constitutes the portion of the magnetic core 3 excluding the first core piece 5. Specifically, the second core piece 6 has the same configuration as the first core piece 5. The second core piece 6 is composed of a second end core portion 32, a part of the middle core portion 30, a part of the first side core portion 33, and a part of the second side core portion 34. The shape of the second core piece 6 as viewed from the Z direction is roughly E-shaped. The portion corresponding to the middle core portion 30 has a second end face 3b parallel to the YZ plane.

[0049] A gap 3g is formed between the first end face 3a and the second end face 3b. This gap 3g functions as a magnetic gap.

[0050] [Magnetic properties, materials, etc.] The first core piece 5 is a molded body of a composite material. Figure 2 is a magnified photograph of a cross-section of the first part 51 of the first core piece 5 cut in the XY plane. As shown in Figure 2, the composite material 9 includes a solidified resin 90 and soft magnetic powder 91 dispersed in the resin 90. In Figure 2, the gray area is the resin 90, and the white area is the individual particles of the soft magnetic powder 91. The soft magnetic powder 91 is an aggregate of soft magnetic particles composed of iron group metals such as iron, or iron alloys such as Fe (iron)-Si (silicon) alloy or Fe-Ni (nickel) alloy. An insulating coating composed of phosphate or the like may be formed on the surface of the soft magnetic particles.

[0051] Resin 90 is, for example, a thermosetting resin or a thermoplastic resin. Examples of thermosetting resins include unsaturated polyester resin, epoxy resin, urethane resin, and silicone resin. Examples of thermoplastic 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. In addition, resin 90 may be BMC (Bulk molding compound) which is an unsaturated polyester mixed with calcium carbonate or glass fibers, millable silicone rubber, or millable urethane rubber.

[0052] The composite material 9 may contain non-metallic powder in addition to the resin 90 and soft magnetic powder 91. The non-metallic powder improves the heat dissipation of the molded body of the composite material 9. The non-metallic powder is, for example, a ceramic filler such as alumina or silica. The ceramic filler is also a non-magnetic material. The content of non-metallic powder in the composite material 9 is, for example, 0.2% by mass or more and 20% by mass or less, more specifically 0.3% by mass or more and 15% by mass or less, and 0.5% by mass or more and 10% by mass or less.

[0053] The content of soft magnetic powder 91 in the composite material 9 is, for example, 30% to 80% by volume. From the viewpoint of improving saturation magnetic flux density and heat dissipation, the content of soft magnetic powder 91 may be further 50% to 60% or 70% by volume. From the viewpoint of improving fluidity in the manufacturing process, the content of soft magnetic powder 91 may be 75% or less by volume. The relative permeability of the molded body of the composite material 9 tends to decrease as the packing density of soft magnetic powder 91 decreases. The relative permeability of the molded body of the composite material 9 is, for example, 5 to 50. The relative permeability of the molded body of the composite material 9 may further be 10 to 45, 15 to 40, or 20 to 35.

[0054] As shown in Figure 2, the multiple particles of the soft magnetic powder 91 contained in the first part 51 are oriented in the Y direction. Here, "the state in which the particles are oriented in the Y direction" means at least one of the following states: a state in which the major axis of the particles is roughly aligned with the Y direction, and a state in which multiple particles are linked together in a chain-like manner so as to reduce magnetoresistance. The first part 51, in which the multiple particles of the soft magnetic powder 91 are oriented in the Y direction, readily allows magnetic flux along the Y direction to pass through. As shown by the dashed arrow in Figure 1, magnetic flux flows in the Y direction through the first part 51. Therefore, the first relative permeability of the first part 51 with respect to magnetic flux along the extension direction of the first part 51 is higher than the relative permeability of a composite material in which the particles are not oriented in any direction.

[0055] Here, the cross-section of the second part 52 in this example, obtained by cutting it in the XY plane, has almost the same appearance as the cross-section shown in Figure 2. In other words, the multiple particles of the soft magnetic powder contained in the second part 52 are also oriented in the Y direction. As shown by the dashed arrow in Figure 1, magnetic flux flows in the second part 52 in the X direction. Magnetic flux does not easily flow in the X direction perpendicular to the orientation direction of the particles. Therefore, the second relative permeability of the second part 52 along the extension direction of the second part 52 is about the same as, or lower than, the relative permeability of a composite material in which the particles are not oriented in any direction.

[0056] As described above, even though the first part 51 and the second part 52 are molded as a single continuous piece without any joints, the first relative permeability is higher than the second relative permeability. The manufacturing method for such a first core piece 5 is as follows.

[0057] The first core piece 5 of the composite material 9 is manufactured by resin molding, in which a mixture of unsolidified resin 90 and soft magnetic powder 91 is filled into a mold and the resin 90 is solidified. During this resin molding, a magnetic field is applied in the direction indicated by the white arrow in Figure 1, i.e., the Y direction. When a magnetic field is applied in the Y direction, multiple particles of the soft magnetic powder 91 are oriented in the Y direction. The larger the magnetic field during resin molding, the more likely it is that the number of particles oriented in the Y direction will increase. The magnitude of the magnetic field is, for example, 15 kOe (approximately 1.19 × 10⁻¹⁰). 6 It may be A / m or higher, or 18kOe (approximately 1.43 × 10⁻¹⁰). 6 It may be A / m or more, or 20kOe(1.59×10 6 A / m or higher is also acceptable.

[0058] Unlike this example, a magnetic field along the X direction in Figure 1 may be applied during resin molding. In that case, multiple particles of the soft magnetic powder 91 will be oriented in the X direction. As a result, the second permeability of the second part 52 with respect to the magnetic flux along the stretching direction of the second part 52 will be higher than the first permeability of the first part 51 with respect to the magnetic flux along the stretching direction of the first part 51.

[0059] As already mentioned, the second core piece 6 in this example has the same configuration as the first core piece 5. That is, the shape, dimensions, material, and structure of the second core piece 6 are all substantially the same as those of the first core piece 5. Therefore, the portion of the second core piece 6 corresponding to the second end core portion 32 has the same configuration as the first portion 51 of the first core piece 5, and the portions corresponding to the other core portions 30, 33, and 34 have the same configuration as the second portion 52 of the first core piece 5.

[0060] ≪Other≫ The reactor 1 in this example may include a resin molded portion that integrates the coil 2 and the magnetic core 3. The resin molded portion may cover the entire assembly of the coil 2 and the magnetic core 3, or it may cover only a part of the assembly. The resin constituting the resin molded portion is, for example, PBT resin. These resins may also contain ceramic fillers such as alumina.

[0061] Summary In this example, reactor 1 exhibits excellent magnetic properties at high frequencies and high currents. The reactor 1 in this example comprises a magnetic core 3 including a first core piece 5. The first core piece 5 is made of a composite material, and the iron loss in the composite material is smaller than the iron loss in the compacted molded body. In addition, the first part 51 of the first core piece 5 is more permeable to magnetic flux than the second part 52. Therefore, magnetic flux is less likely to leak from the first part 51 to the outside of the reactor 1. Since the first core piece 5 made of the composite material can be considered to have a magnetic gap, the first core piece 5 is less likely to become magnetically saturated. The reactor 1 in this example further comprises a second core piece 6 having the same configuration as the first core piece 5. Therefore, the reactor 1 in this example exhibits excellent magnetic properties at high frequencies and high currents.

[0062] In this example, reactor 1 offers excellent productivity. The magnetic core 3 in reactor 1 in this example is composed of a first core piece 5 and a second core piece 6. Therefore, the magnetic core 3 is completed simply by combining the first core piece 5 and the second core piece 6. Furthermore, the first core piece 5 and the second core piece 6 have the same structure. That is, the first core piece 5 and the second core piece 6 are manufactured using exactly the same manufacturing method. Consequently, only one mold and one type of composite material are needed to produce the magnetic core 3.

[0063] ≪Extreme Variation 1≫ The following describes two modified examples 1 and 2. These examples primarily describe the differences from Embodiment 1. Other configurations are common to Embodiment 1. The second core piece 6 in Modified Example 1 may be a powder compact. The powder compact is produced by pressure molding a raw material powder containing soft magnetic powder. This soft magnetic powder is not particularly limited; the raw material powder may contain a lubricant. The powder compact allows for a higher soft magnetic powder content than a composite material 9. For example, the soft magnetic powder content in the powder compact is over 80% by volume, and more specifically, 85% by volume or more. The powder compact tends to have a high saturation magnetic flux density and relative permeability. The relative permeability of the powder compact is, for example, 50 to 500. The relative permeability of the powder compact may also be 80 or higher, 100 or higher, 150 or higher, or 180 or higher.

[0064] The magnetic core 3 comprises a first core piece 5 made of a molded composite material and a second core piece 6 made of a compacted powder molded body, which makes it easier to reduce leakage flux and adjust the inductance.

[0065] <<Variation 2>> The second core piece 6 may be a molded body of a composite material produced without applying a magnetic field during resin molding. Unlike the first modification, this second modification does not require a mold for producing the compacted powder molded body.

[0066] <Embodiment 2> Reactor 1 according to Embodiment 2 will be described with reference to Figure 3. The reactor 1 of Embodiment 2 and the reactor 1 of Embodiment 1 differ in the division state of the magnetic core 3. Other than the division state of the magnetic core 3 in reactor 1 of this example, the configuration is the same as reactor 1 of Embodiment 1.

[0067] The first core piece 5 in this example is composed of a first end core portion 31, a part of the middle core portion 30, and a first side core portion 33. The first core piece 5, when viewed from the Z direction, is roughly F-shaped. The first core piece 5 is a molded body of a composite material in which soft magnetic powder is oriented in the Y direction or the X direction.

[0068] The second core piece 6 is composed of a second end core portion 32, a part of the middle core portion 30, and a second side core portion 34. The second core piece 6, as viewed from the Z direction, is roughly F-shaped. The shape of the second core piece 6 as viewed from the Z direction may be the same as or different from the shape of the first core piece 5. The second core piece 6 is a molded body of a composite material in which soft magnetic powder is oriented in the Y direction or the X direction. Unlike this example, the second core piece 6 may be a compacted powder molded body.

[0069] <Embodiment 3> Reactor 1 according to Embodiment 3 will be described with reference to Figure 4. In this example, the differences between Reactor 1 of Embodiment 3 and Reactor 1 of Embodiment 1 will be explained in detail.

[0070] The first core piece 5 in this example is composed of a first end core portion 31, a part of the middle core portion 30, a first side core portion 33, and a second side core portion 34. The first core piece 5, when viewed from the Z direction, is roughly E-shaped. The first core piece 5 is a molded body of a composite material in which soft magnetic powder is oriented in the Y direction or the X direction.

[0071] The second core piece 6 is composed of a second end core portion 32 and a part of the middle core portion 30. When viewed from the Z direction, the second core piece 6 is roughly T-shaped. The second core piece 6 is a molded body of a composite material in which soft magnetic powder is oriented in the Y direction or the X direction.

[0072] In this example, coil 2 comprises a single winding section 21. The winding section 21 is located on the outer circumference of the middle core section 30. In this example, where the winding section 21 is located on the outer circumference of the middle core section 30, the magnetic properties of the reactor 1 tend to be higher when the second relative permeability of the second section 52 is higher than the first relative permeability of the first section 51.

[0073] Unlike this example, the second core piece 6 may be a compacted powder molded body. Also, the coil 2 may have two winding sections 21. In that case, one winding section 21 is located on the outer circumference of the first side core section 33, and the other winding section 21 is located on the outer circumference of the second side core section 34.

[0074] <Embodiment 4> A reactor 1 according to Embodiment 4 will be described with reference to Figure 5. The magnetic core 3 in this example is rectangular and annular. The magnetic core 3 comprises two inner core portions 35, 36 and two outer core portions 37, 38. The inner core portions 35, 36 are arranged inside the winding portions 21, 22. The outer core portions 37, 38 are positioned facing the end faces of the winding portions 21, 22.

[0075] The magnetic core 3 is composed of two divided pieces 3C and 3D. Divided piece 3C is composed of a part of the inner core portion 35, a part of the inner core portion 36, and an outer core portion 37. Divided piece 3D is composed of a part of the inner core portion 35, a part of the inner core portion 36, and an outer core portion 38. When viewed from the Z direction, divided pieces 3C and 3D are roughly U-shaped. Divided pieces 3C and 3D are molded bodies of composite material in which soft magnetic powder is oriented in the Y direction or the X direction. Therefore, divided piece 3C is a first core piece 5 comprising one first portion 51 and two second portions 52, and divided piece 3D is a second core piece 6 comprising one first portion 51 and two second portions 52. The first core piece 5 and the second core piece 6 have the same configuration. Unlike this example, the second core piece 6 may be a compacted powder molded body.

[0076] As an alternative, the first core piece 5 and the second core piece 6, as viewed from the Z direction, may be roughly L-shaped. That is, the first core piece 5 may be composed of an inner core portion 35 and an outer core portion 37, and the second core piece 6 may be composed of an inner core portion 36 and an outer core portion 38.

[0077] <Embodiment 5> <<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.

[0078] As shown in Figure 6, 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. 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 6, the charging point of the vehicle 1200 is an inlet, but it may also be equipped with a plug.

[0079] 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.

[0080] As shown in Figure 7, 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.

[0081] 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.

[0082] A converter 1110 and a power converter 1100 equipped with a reactor 1 of an embodiment having stable magnetic properties exhibit stable and excellent magnetic properties.

[0083] <Test Example 1> In Test Example 1, the effect of the first core piece 5, which has a partially different relative permeability, on the performance of reactor 1 was investigated. In this test, a test reactor containing the first core piece 5 and a test reactor containing a core piece made of a conventional composite material were fabricated, and the inductance of both test reactors was compared. The appearance of both test reactors is the same as reactor 1 shown in Figure 4. Therefore, the following explanation will refer to Figure 4.

[0084] Sample No. 1 Segment 3A of the test reactor for sample No. 1 is a molded composite material produced without applying a magnetic field during resin molding. Segment 3B of the test reactor for sample No. 1 is a compacted powder molded body.

[0085] Sample No. 2 The segment 3A in the test reactor of sample No. 2 is the first core piece 5, which was manufactured by resin molding while applying a magnetic field in the X direction. The segment 3B in the test reactor of sample No. 2 is a compacted molded body having the same configuration as sample No. 1.

[0086] The inductances of sample No. 1 and sample No. 2 were measured under the same measurement conditions. As a result, the inductance of sample No. 2 was 6% higher than that of sample No. 1. Therefore, it was found that the first core piece 5 containing soft magnetic powder oriented in the X direction contributed to the improvement of the magnetic properties of reactor 1.

[0087] <Test Example 2> From the first core piece 5 of Test Example 1, the first and second test pieces were cut out in a cubic shape from the first part 51 and the second part 52, respectively, and the relative permeability of each test piece was measured using a BH evaluation facility. The size of each test piece was 7 mm × 7 mm × 7 mm.

[0088] The relative permeability of the first part 51 in the Y direction was measured by applying the magnetic field of the BH evaluation equipment to the Y direction of the first test specimen. Specifically, the first test specimen was set in the BH evaluation equipment so that its Y direction was aligned with the magnetic field of the BH evaluation equipment, and the relative permeability of the first test specimen was measured. In addition, the relative permeability of the second part 52 in the X direction was measured by applying the magnetic field of the BH evaluation equipment to the X direction of the second test specimen. Specifically, the second test specimen was set in the BH evaluation equipment so that its X direction was aligned with the magnetic field of the BH evaluation equipment, and the relative permeability of the second test specimen was measured. As a result, it was found that the relative permeability of the second part 52 in the X direction was higher than the relative permeability of the first part 51 in the Y direction. [Explanation of Symbols]

[0089] 1 Reactor 2 coils 21 Winding section, 2a, 2b ends 3 Magnetic core 3a first end face, 3b second end face, 3g gap 3A,3B,3C,3D split piece 30 Middle core section, 31 First end core section, 32 Second end core section 33 First side core section, 34 Second side core section 35, 36 Inner core section, 37, 38 Outer core section 5. First core piece 51 Part 1, 52 Part 2 6. Second core piece 9 Composite materials 90 Resin, 91 Soft magnetic powder 1100 Power converter 1110 Converter, 1111 Switching element, 1112 Drive circuit 1115 Reactor, 1120 Inverter 1150 Converter for power supply equipment, 1160 Converter for auxiliary power supply equipment 1200 vehicles 1210 Main battery, 1220 Motor, 1230 Sub-battery 1240 Auxiliary equipment, 1250 Wheels 1300 engine L, T0, T1, T2, T3, T4 Length W width

Claims

1. A reactor comprising a coil having a wound portion and a magnetic core, The magnetic core has a plurality of segmented pieces, including a first core piece. The first core piece is made of a composite material comprising a resin and soft magnetic powder dispersed in the resin. A first portion extending in a direction perpendicular to the axial direction of the winding portion and positioned facing the end face of the winding portion, It comprises a second portion extending from the first portion in the axial direction, The composition of the first part and the second part are the same, The first part and the second part are formed in a continuous manner without any joint. The plurality of soft magnetic particles constituting the soft magnetic powder contained in the first portion and the plurality of soft magnetic particles constituting the soft magnetic powder contained in the second portion are both oriented in a direction along the length of the first portion or in a direction along the length of the second portion. The first relative permeability of the first portion with respect to the magnetic flux along the extension direction of the first portion is different from the second relative permeability of the second portion with respect to the magnetic flux along the extension direction of the second portion. Reactor.

2. The reactor according to claim 1, wherein the first relative permeability is higher than the second relative permeability.

3. The first core piece has an E-shape, comprising a base and three legs extending from the base. The base is the first part, The reactor according to claim 1 or claim 2, wherein each of the three legs is the second part.

4. The reactor according to claim 3, wherein the magnetic core comprises the first core piece and a second core piece having the same configuration as the first core piece.

5. A segmented piece that constitutes part of the magnetic core of the reactor, It is composed of a composite material comprising a resin and soft magnetic powder dispersed in the resin. Part one, It comprises a second portion extending in a direction perpendicular to the extension direction of the first portion, The composition of the first part and the second part are the same, The first part and the second part are formed in a continuous manner without any joint. The plurality of soft magnetic particles constituting the soft magnetic powder contained in the first portion and the plurality of soft magnetic particles constituting the soft magnetic powder contained in the second portion are both oriented in a direction along the length of the first portion or in a direction along the length of the second portion. The first relative permeability of the first portion with respect to the magnetic flux along the extension direction of the first portion is different from the second relative permeability of the second portion with respect to the magnetic flux along the extension direction of the second portion. Split pieces.

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

7. A converter according to claim 6, Power converter.

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