Reactor, divided piece, converter, and power conversion device

Abstract

A reactor is provided with a coil having a winding part, and a magnetic core having a plurality of divided pieces including a first chip, the first chip comprising a composite material containing a resin and a soft magnetic powder dispersed in the resin, the first chip having a first portion and a second portion, and the first portion and the second portion being formed of a composite material containing a resin and a soft magnetic powder dispersed in the resin. The first portion extends in a direction orthogonal to the axial direction of the winding portion and is disposed on an end surface facing the winding portion, the second portion extends from the first portion in the axial direction, and the first portion and the second portion are continuously formed without a seam. A first relative permeability of the first portion with respect to a magnetic flux along an extension direction of the first portion is different from a second relative permeability of the second portion with respect to a magnetic flux along an extension direction of the second portion.

Description

Technical Field

[0001] The present invention relates to a reactor, a splitter, a converter and a power conversion device. This application claims priority based on Japanese Patent Application No. 2022-100680 filed in Japan on June 22, 2022, and incorporates all the contents described in the aforementioned Japanese application. Background Art

[0002] Among the components of the converter provided in hybrid vehicles and the like, there is a reactor. For example, the reactors described in Patent Documents 1 and 2 include a coil and a magnetic core. The coil includes a winding portion formed by winding a winding wire. The number of winding portions may be one or more.

[0003] The magnetic core is formed by combining a plurality of split pieces. The split pieces are, for example, a powder compact formed by pressurizing soft magnetic powder, or a composite compact formed by dispersing soft magnetic powder in resin. The composite compact can easily achieve the desired magnetic properties by changing the mixing ratio of soft magnetic powder and resin. The composite compact can reduce the iron loss of the reactor in use at high frequencies. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-135334 Patent Document 2: Japanese Patent Application Publication No. 2016-201509 Summary of the invention Problems to be solved by the invention

[0005] The reactor of the present invention, A coil and a magnetic core are provided, wherein the coil has a winding portion, The magnetic core has a plurality of divided pieces including a first core piece, The first chip is composed of a composite material containing a resin and a soft magnetic powder dispersed in the resin, and the first chip includes a first part and a second part. The first portion extends in a direction perpendicular to the axial direction of the winding portion and is arranged at a position facing the end surface of the winding portion. The second portion extends from the first portion along the axis direction, The first part and the second part are continuously formed without a joint, A first relative magnetic permeability of the first portion with respect to a magnetic flux along an extending direction of the first portion is different from a second relative magnetic permeability of the second portion with respect to a magnetic flux along an extending direction of the second portion.

[0006] The split piece of the present invention A part of the magnetic core of the reactor. The split piece is composed of a composite material containing a resin and a soft magnetic powder dispersed in the resin. The split piece comprises a first part and a second part. The second portion extends in a direction orthogonal to an extending direction of the first portion, The first part and the second part are continuously formed without a joint, A first relative magnetic permeability of the first portion with respect to a magnetic flux along an extending direction of the first portion is different from a second relative magnetic permeability of the second portion with respect to a magnetic flux along an extending direction of the second portion.

[0007] A converter according to the present invention includes the reactor according to the present invention.

[0008] A power conversion device according to the present invention includes the converter according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic plan view of the reactor according to the first embodiment. Figure 2 yes Figure 1 A photograph of an XY cross section of a first portion of the reactor shown. Figure 3 This is a schematic plan view of the reactor according to the second embodiment. Figure 4 This is a schematic plan view of the reactor according to the third embodiment. Figure 5 This is a schematic plan view of the reactor according to the fourth embodiment. Figure 6 The diagram schematically shows the configuration of a power supply system of a hybrid vehicle. Figure 7 This is a circuit diagram schematically showing an example of a power conversion device including a converter. DETAILED DESCRIPTION

[0010] [Problems to be Solved by the Invention] In recent years, reactors tend to be used in high frequency and high current. In split pieces composed of pressed powder, iron loss may increase with high frequency. In split pieces composed of composite materials, although iron loss is small, leakage flux tends to increase. Therefore, a reactor with split pieces that suppress the increase of iron loss and leakage flux is required. Such a reactor has excellent magnetic properties especially in high frequency and high current.

[0011] One of the objects of the present invention is to provide a reactor having a magnetic core capable of suppressing an increase in iron loss and an increase in leakage magnetic flux. Another object of the present invention is to provide a splitter capable of suppressing an increase in iron loss and an increase in leakage magnetic flux. Furthermore, another object of the present invention is to provide a converter and a power conversion device having a reactor having excellent magnetic characteristics.

[0012] [Effects of the Invention] In the reactor and the split piece of the present invention, an increase in iron loss and an increase in leakage flux can be suppressed. In addition, the converter and the power conversion device of the present invention operate stably.

[0013] [Description of Embodiments of the Invention] First, embodiments of the present invention will be described by way of examples.

[0014] <1> A reactor according to an embodiment of the present invention, A coil and a magnetic core are provided, wherein the coil has a winding portion, The magnetic core has a plurality of divided pieces including a first core piece, The first chip is composed of a composite material containing a resin and a soft magnetic powder dispersed in the resin, and the first chip includes a first part and a second part. The first portion extends in a direction perpendicular to the axial direction of the winding portion and is arranged at a position facing the end surface of the winding portion. The second portion extends from the first portion along the axis direction, The first part and the second part are continuously formed without a joint, A first relative magnetic permeability of the first portion with respect to a magnetic flux along an extending direction of the first portion is different from a second relative magnetic permeability of the second portion with respect to a magnetic flux along an extending direction of the second portion.

[0015] In the first chip composed of a composite material, iron loss is less likely to increase compared to a chip composed of a pressed powder molded body. This is because: in the composite material, the resin enters between the particles of the soft magnetic powder, and the particles are difficult to contact each other, so the increase in iron loss can be suppressed. In the first chip in the above structure, the ease of passage of the magnetic flux of the first part and the second part is anisotropic. Specifically, the extension direction of the first part and the extension direction of the second part are orthogonal to each other, and either the first relative magnetic permeability along the extension direction of the first part and the second relative magnetic permeability along the extension direction of the second part is higher than the other. The portion with high relative magnetic permeability suppresses the increase of leakage magnetic flux in the first chip. The reactor with such a first chip exhibits excellent magnetic properties particularly in high frequencies and large currents.

[0016] In the first chip, resin is interposed between each particle of the soft magnetic powder, so the first chip is considered to have a magnetic gap. Therefore, the magnetic core including the first chip is difficult to be magnetically saturated. The reactor with the first chip that is difficult to be magnetically saturated operates stably, especially in high frequency and large current.

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

[0018] The first portion having the first relative magnetic permeability is arranged outside the winding portion of the coil. The leakage magnetic flux in the first portion may have an adverse effect on other electronic devices arranged near the inductor. When the first relative magnetic permeability is high, the leakage magnetic flux in the first portion is reduced, and the adverse effect on other electronic devices is reduced.

[0019] <3> In the above <1> or <2> The reactor may also be: The first chip is in an E-shape having a base and three legs extending from the base. The base is the first part, The three legs are respectively the second parts.

[0020] In the above structure, the number of divisions of the magnetic core can be reduced. The chip combined with the E-shaped chip is an E-shaped chip, a T-shaped chip, or an I-shaped chip. In this case, the number of divisions of the magnetic core is two.

[0021] <4> In the above <1> to <3> In the reactor described in any one of the above, it may also be, The magnetic core is composed of the first chip and a second chip, and the second chip has the same structure as the first chip.

[0022] "The same structure" means that the shape, size, material and organization are all substantially the same. <4> In the structure, the first chip and the second chip are made of the same composite material and the same mold. Therefore, the productivity of the magnetic core is improved, and the productivity of the reactor including the magnetic core is also improved.

[0023] The first chip and the second chip having the same structure are, for example, chips in the shape of letter E. Alternatively, the first chip and the second chip may be, for example, chips in the shape of letter F.

[0024] <5> Divided piece of embodiment A part of the magnetic core of the reactor. The split piece is composed of a composite material containing a resin and a soft magnetic powder dispersed in the resin. The split piece comprises a first part and a second part. The second portion extends in a direction orthogonal to an extending direction of the first portion, The first part and the second part are continuously formed without a joint, A first relative magnetic permeability of the first portion with respect to a magnetic flux along an extending direction of the first portion is different from a second relative magnetic permeability of the second portion with respect to a magnetic flux along an extending direction of the second portion.

[0025] In the split piece made of composite material, iron loss is difficult to increase compared with the split piece made of pressed powder. This is because the resin easily enters between the particles of the soft magnetic powder. In the split piece of the above structure, either the first part or the second part has a higher relative permeability than the other. The part with high relative permeability suppresses the increase of leakage flux in the split piece.

[0026] <6> The converter according to the embodiment includes the above <1> to <5> The reactor according to any one of the preceding claims.

[0027] The converter includes the reactor of the embodiment which has excellent magnetic characteristics and is less likely to be magnetically saturated. Therefore, the converter exhibits stable and excellent performance.

[0028] <7> The power conversion device according to the embodiment includes the above <6> The converter.

[0029] The power conversion device includes a converter that exhibits stable and excellent performance. Therefore, the power conversion device exhibits stable and excellent performance.

[0030] [Details of Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. The same reference numerals in the drawings represent the same names. In addition, the present invention is not limited to the structures shown in the embodiments, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0031] <Implementation Method 1> Figure 1 The reactor 1 of the present example shown is composed of a combination of a coil 2 and a magnetic core 3. One of the characteristics of the reactor 1 is that the magnetic core 3 includes a first core 5, the first core 5 is composed of a molded body of a composite material, and the relative magnetic permeability partially changes in the first core 5. The various structures of the reactor 1 are described in detail below.

[0032] Coil The coil 2 has at least one winding portion 21, 22. The coil 2 of this example has a winding portion 21 and a winding portion 22. The winding portions 21, 22 are formed by winding a winding wire in a spiral shape. The winding wire can use a known winding wire. The winding wire of this method is a coated flat wire composed of a conductor wire having an insulating coating layer. The conductor wire is composed of, for example, a copper flat wire. The insulating coating layer is composed of, for example, enamel. The winding portions 21, 22 of this example are flat coils formed by winding the coated flat wire flatly.

[0033] The winding parts 21 and 22 are in the shape of a rectangular cylinder. That is, the end surface shape of the winding parts 21 and 22 of this example is in the shape of a rectangular frame. The corners of the winding parts 21 and 22 of this example are rounded. Since the winding parts 21 and 22 are in the shape of a rectangular cylinder, the contact area between the winding parts 21 and the installation object is likely to be larger than when the winding parts are in the shape of a cylinder with the same cross-sectional area. Therefore, the reactor 1 can easily dissipate heat to the installation object via the winding parts 21 and 22. In addition, the installation state of the winding parts 21 and 22 relative to the installation object is likely to be stabilized.

[0034] The ends of the winding parts 21 and 22 (not shown) are pulled toward the outer peripheral side of the winding parts 21 and 22. The insulating coating is peeled off at the ends of the winding parts 21 and 22 to expose the conductor wire. The exposed conductor wire is connected to a terminal member (not shown). The winding parts 21 and 22 of this example are connected to independent power supplies respectively. Different from this example, the winding parts 21 and 22 can also be connected to one power supply.

[0035] Magnetic Core The magnetic core 3 includes 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. The magnetic core 3 of this example is in the shape of a figure 8 formed by connecting two rings. Figure 1 In the figure, the boundaries of each core portion are indicated by double dotted 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 surface of the winding portion 21, 22, that is, the end surface on the right side of the paper. The second end core portion 32 faces the second end surface of the winding portion 21, 22, that is, the end surface on the left side of the paper. The first side core portion 33 is arranged on the inner side of the winding portion 21. The second side core portion 34 is arranged on the inner side of the winding portion 22.

[0036] In the magnetic core 3, a closed annular magnetic circuit indicated by a thick dotted line is 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. In addition, a closed annular magnetic circuit indicated by a thick dotted line is 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 directions in the reactor 1 are defined with reference to the magnetic core 3. First, the direction along the axial direction of the middle core 30 is the X direction. The direction orthogonal to the X direction and in which the middle core 30, the first side core 33, and the second side core 34 are arranged in parallel is the Y direction. And, the direction orthogonal to both the X direction and the Y direction is the Z direction. In this specification, the axial direction of a component includes a direction along the axis of the component from one end toward the other end of the component and a direction opposite to the direction.

[0038] [Middle core] The extending direction of the intermediate core 30, that is, the axial direction, is along the axial directions of the windings 21 and 22. As shown in Embodiment 3 described later, when there is only one winding 21, the winding 21 is arranged on the outer periphery of the intermediate core 30.

[0039] The shape of the middle core 30 is not particularly limited as long as it is a shape that forms a sufficient magnetic circuit inside the middle core 30. The middle core 30 of this example is roughly rectangular. Two magnetic circuits are formed in the middle core 30. Therefore, the magnetic circuit cross-sectional area of ​​the middle core 30 is larger than the magnetic circuit cross-sectional area of ​​the first side core 33 and the magnetic circuit cross-sectional area of ​​the second side core 34.

[0040] [First end core portion and second end core portion] The first end core portion 31 and the second end core portion 32 extend in the Y direction orthogonal 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 extends outward from the middle core portion 30 in the Y direction. The second end core portion 32 extends outward from the middle core portion 30 in the Y direction.

[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 form a sufficient magnetic circuit inside each end core portion 31, 32. The first end core portion 31 and the second end core portion 32 of this example are roughly rectangular. Two of the four corners of the first end core portion 31 and the second end core portion 32 viewed from the Z direction, which are located far away from the two side core portions 33, 34, may also have rounded corners. When the above two corners have rounded corners, the weight of the end core portions 31, 32 is reduced. The above two corners are portions where magnetic flux is difficult to pass through. Therefore, even if the above two corners are rounded, the magnetic properties of the reactor 1 are difficult to reduce.

[0042] [First side core portion and second side core portion] The first side core portion 33 connects one end of the first end core portion 31 and one end of the second end core portion 32. The axial direction of the first side core portion 33 is parallel to the axial direction of the middle core portion 30. The first side core portion 33 is disposed inside the winding portion 21.

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

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

[0045] The length T0 of the middle core portion 30 in the Y direction is, for example, greater than 10 mm and less than 50 mm. The length T1 of the first end core portion 31 in the X direction and the length T2 of the second end core portion 32 in the X direction are, for example, greater than 5 mm and less than 40 mm. In addition, the length T3 of the first side core portion 33 in the Y direction and the length T4 of the second side core portion 34 in the Y direction are, for example, greater than 5 mm and less than 40 mm. These lengths are related to the size of the magnetic path cross-sectional area of ​​the magnetic core 3.

[0046] [Split method] The magnetic core 3 is composed of a plurality of split pieces 3A and 3B. The number of split pieces 3A and 3B in this example is two, but it can also be three or more. The split piece 3A is a first chip 5 composed of a molded body of a composite material described later. The first chip 5 is a molded body and has no seams. The split piece 3B is a second chip 6 composed of a molded body of a composite material. The second chip 6 has the same structure as the first chip 5.

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

[0048] The second chip 6 of this example constitutes the portion of the magnetic core 3 other than the first chip 5. Specifically, the second chip 6 has the same structure as the first chip 5. The second chip 6 is composed of a second end core portion 32, a portion of the middle core portion 30, a portion of the first side core portion 33, and a portion of the second side core portion 34. The shape of the second chip 6 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 surface 3a and the second end surface 3b. The gap 3g functions as a magnetic gap.

[0050] [Magnetic properties, materials, etc.] The first core sheet 5 is a shaped body of a composite material. Figure 2 FIG. 5 is an enlarged photograph of a cross section of the first portion 51 of the first chip 5 cut along the XY plane. Figure 2 As shown, the composite material 9 contains a cured resin 90 and a soft magnetic powder 91 dispersed in the resin 90. Figure 2 In the figure, the gray part is the resin 90, and the white part is each particle 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) alloys and Fe-Ni (nickel) alloys. An insulating coating layer composed of phosphate or the like may be formed on the surface of the soft magnetic particles.

[0051] The resin 90 is, for example, a thermosetting resin or a thermoplastic resin. Examples of thermosetting resins include unsaturated polyester resins, epoxy resins, polyurethane resins, and silicone resins. Examples of thermoplastic resins include polyphenylene sulfide (PPS) resins, polytetrafluoroethylene (PTFE) resins, liquid crystal polymers (LCP), polyamide (PA) resins such as nylon 6 or nylon 66, polybutylene terephthalate (PBT) resins, and acrylonitrile-butadiene-styrene (ABS) resins. In addition, the resin 90 may be a BMC (bulk molding compound) in which calcium carbonate or glass fiber is mixed in an unsaturated polyester, a kneaded silicone rubber, or a kneaded polyurethane rubber.

[0052] The composite material 9 may contain non-metallic powder in addition to the resin 90 and the 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 the non-metallic powder in the composite material 9 is, for example, 0.2 mass % or more and 20 mass % or less, further 0.3 mass % or more and 15 mass % or less, or 0.5 mass % or more and 10 mass % or less.

[0053] The content of the soft magnetic powder 91 in the composite material 9 is, for example, greater than 30% by volume and less than 80% by volume. From the viewpoint of improving the saturation magnetic flux density or heat dissipation, the content of the soft magnetic powder 91 may further be greater than 50% by volume, greater than 60% by volume, or greater than 70% by volume. From the viewpoint of improving fluidity during the manufacturing process, the content of the soft magnetic powder 91 may also be less than 75% by volume. The smaller the filling rate of the soft magnetic powder 91, the easier it is to reduce the relative magnetic permeability of the formed body of the composite material 9. The relative magnetic permeability of the formed body of the composite material 9 is, for example, greater than 5 and less than 50. The relative magnetic permeability of the formed body of the composite material 9 may further be greater than 10 and less than 45, greater than 15 and less than 40, or greater than 20 and less than 35.

[0054] like Figure 2 As shown, the multiple particles of the soft magnetic powder 91 contained in the first part 51 are oriented in the Y direction. The "state of particles oriented in the Y direction" mentioned here refers to at least one of a state in which the major axis of the particles is roughly along the Y direction and a state in which multiple particles are linked in a chain to reduce magnetic resistance. The first part 51 in which multiple particles of the soft magnetic powder 91 are oriented in the Y direction makes it easy for magnetic flux along the Y direction to pass through. Figure 1 As shown by the dashed arrow, in the first portion 51, the magnetic flux flows in the Y direction. Therefore, the first relative magnetic permeability of the first portion 51 with respect to the magnetic flux along the extension direction of the first portion 51 is higher than the relative magnetic permeability of the composite material in which the particles are not oriented in any direction.

[0055] Here, the cross section of the second portion 52 of this example cut along the XY plane also has the same Figure 2 That is, the plurality of particles of the soft magnetic powder contained in the second portion 52 are also oriented in the Y direction. Figure 1 As shown by the dotted arrow in the middle, the magnetic flux flows in the X direction in the second portion 52. The magnetic flux is difficult to flow in the X direction orthogonal to the orientation direction of the particles. Therefore, the second relative magnetic permeability of the second portion 52 along the extension direction of the second portion 52 is the same as or lower than the relative magnetic permeability of the composite material in which the particles are not oriented in any direction.

[0056] As described above, although the first portion 51 and the second portion 52 are continuously formed without a seam, the first relative magnetic permeability is higher than the second relative magnetic permeability. The manufacturing method of such a first chip 5 is as follows

[0057] The first core 5 of the composite material 9 is manufactured by filling a mixture of uncured resin 90 and soft magnetic powder 91 into a mold and curing the resin 90 to form a resin. Figure 1A magnetic field is applied in the direction indicated by the hollow arrow, i.e., in the Y direction. By applying a magnetic field in the Y direction, a plurality of particles of the soft magnetic powder 91 are oriented in the Y direction. The larger the magnetic field during resin molding, the more likely the number of particles oriented in the Y direction will increase. The magnitude of the magnetic field can be, for example, 15 kOe (approximately 1.19×10 6 A / m) or more, and can also be 18kOe (about 1.43×10 6 A / m) or more, and can also be 20kOe (15.9×10 6 A / m) or above.

[0058] Unlike this example, during resin molding, it is also possible to apply Figure 1 In this case, the plurality of particles of the soft magnetic powder 91 are oriented in the X direction. As a result, the second relative magnetic permeability of the second portion 52 with respect to the magnetic flux along the extending direction of the second portion 52 is higher than the first relative magnetic permeability of the first portion 51 with respect to the magnetic flux along the extending direction of the first portion 51.

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

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

[0061] "Summarize" The reactor 1 of this example exhibits excellent magnetic characteristics in high-frequency and large current conditions. The reactor 1 of this example has a magnetic core 3 including a first chip 5. The first chip 5 is made of a composite material, and the iron loss in the composite material is smaller than the iron loss in the pressed powder body. In addition, the first part 51 of the first chip 5 allows magnetic flux to pass more easily than the second part 52. Therefore, it is difficult for the magnetic flux to leak from the first part 51 to the outside of the reactor 1. Because the first chip 5 composed of a composite material can be regarded as having a magnetic gap, the first chip 5 is difficult to be magnetically saturated. The reactor 1 of this example also has a second chip 6, and the second chip 6 has the same structure as the first chip 5. Therefore, the reactor 1 of this example exhibits excellent magnetic properties in high frequencies and large currents.

[0062] The reactor 1 of this example is excellent in productivity. The magnetic core 3 of the reactor 1 of this example is composed of a first chip 5 and a second chip 6. Therefore, the magnetic core 3 can be completed by simply combining the first chip 5 and the second chip 6. In addition, the first chip 5 and the second chip 6 have the same structure. That is, the first chip 5 and the second chip 6 are manufactured by exactly the same manufacturing method. Therefore, the mold prepared for making the magnetic core 3 can be one, and the composite material can also be one.

[0063] 《Variant 1》 The following describes variants 1 and 2. In variants 1 and 2, the differences from embodiment 1 are mainly described. The structure other than the difference is shared with embodiment 1. The second chip 6 of variant 1 may also be a powder compact. The powder compact is made by press-forming a raw material powder containing a soft magnetic powder. The soft magnetic powder is not particularly limited. The raw material powder may also contain a lubricant. It is easier to increase the content of soft magnetic powder in the powder compact than in the compact of the composite material 9. For example, the content of soft magnetic powder in the powder compact exceeds 80% by volume, and further is 85% by volume or more. The powder compact tends to have a high saturation magnetic flux density and relative magnetic permeability. The relative magnetic permeability of the powder compact is, for example, greater than 50 and less than 500. The relative magnetic permeability of the powder compact may also be greater than 80, greater than 100, greater than 150, or greater than 180.

[0064] The magnetic core 3 includes the first core sheet 5 formed of a composite material molded body and the second core sheet 6 formed of a powder molded body, thereby making it easy to reduce leakage magnetic flux and to adjust inductance.

[0065] 《Variant 2》 The second core piece 6 may be a composite material molded body produced without applying a magnetic field during resin molding. In this modification 2, unlike the modification 1, a mold for producing a powder molded body is not required.

[0066] <Implementation Method 2> based on Figure 3 The reactor 1 of the second embodiment is described. The reactor 1 of the second embodiment differs from the reactor 1 of the first embodiment in the division state of the magnetic core 3. The structure of the reactor 1 of this example is the same as that of the reactor 1 of the first embodiment except for the division state of the magnetic core 3.

[0067] The first core sheet 5 of this example is composed of the first end core portion 31, a part of the middle core portion 30 and the first side core portion 33. The first core sheet 5 viewed from the Z direction is substantially F-shaped. The first core sheet 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 chip 6 is composed of a second end core portion 32, a portion of the middle core portion 30 and a second side core portion 34. The second chip 6 viewed from the Z direction is roughly F-shaped. The shape of the second chip 6 viewed from the Z direction can be the same as or different from the shape of the first chip 5. The second chip 6 is a molded body of a composite material in which soft magnetic powder is oriented in the Y direction or the X direction. Different from this example, the second chip 6 can also be a pressed powder molded body.

[0069] <Implementation Method 3> based on Figure 4 A reactor 1 according to a third embodiment will be described. In this example, the reactor 1 according to the third embodiment will be described mainly around differences between the reactor 1 according to the first embodiment.

[0070] The first core 5 of this example is composed of a first end core portion 31, a portion of the middle core portion 30, a first side core portion 33, and a second side core portion 34. The first core 5 viewed from the Z direction is roughly in the shape of a letter E. The first core 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 sheet 6 is composed of the second end core portion 32 and a part of the intermediate core portion 30. The second core sheet 6 is substantially T-shaped when viewed from the Z direction. The second core sheet 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] The coil 2 of this example includes one winding portion 21. The winding portion 21 is arranged on the outer periphery of the intermediate core portion 30. In this example where the winding portion 21 is arranged on the outer periphery of the intermediate core portion 30, when the second relative magnetic permeability of the second portion 52 is higher than the first relative magnetic permeability of the first portion 51, the magnetic characteristics of the reactor 1 are easily improved.

[0073] Unlike this example, the second core sheet 6 may also be a powder compact. In addition, the coil 2 may also include two windings 21. In this case, one winding 21 is disposed on the periphery of the first side core 33, and the other winding 21 is disposed on the periphery of the second side core 34.

[0074] <Implementation Method 4> based on Figure 5 The reactor 1 of the fourth embodiment is described. The magnetic core 3 of this example is rectangular ring-shaped. The magnetic core 3 includes two inner core portions 35 and 36 and two outer core portions 37 and 38. The inner core portions 35 and 36 are arranged inside the winding portions 21 and 22. The outer core portions 37 and 38 are arranged at positions facing the end surfaces of the winding portions 21 and 22.

[0075] The magnetic core 3 is composed of two split pieces 3C and 3D. The split piece 3C is composed of a part of the inner core 35, a part of the inner core 36 and the outer core 37. The split piece 3D is composed of a part of the inner core 35, a part of the inner core 36 and the outer core 38. The split pieces 3C and 3D viewed from the Z direction are roughly U-shaped. The split pieces 3C and 3D are molded bodies of composite materials in which soft magnetic powder is oriented in the Y direction or the X direction. Therefore, the split piece 3C is a first chip 5 having a first part 51 and two second parts 52, and the split piece 3D is a second chip 6 having a first part 51 and two second parts 52. The first chip 5 and the second chip 6 have the same structure. Unlike this example, the second chip 6 can also be a pressed powder molded body.

[0076] As a modified example, the first core sheet 5 and the second core sheet 6 may be substantially L-shaped when viewed from the Z direction. That is, the first core sheet 5 may be composed of the inner core section 35 and the outer core section 37 , and the second core sheet 6 may be composed of the inner core section 36 and the outer core section 38 .

[0077] <Implementation method 5> 《Converter·Power Conversion Device》 The reactor 1 of the above-mentioned embodiment can be used for applications that satisfy the following power-on conditions. Examples of the power-on conditions are: a maximum DC current of 100 A or more and 1000 A or less, an average voltage of 100 V or more and 1000 V or less, and an operating frequency of 5 kHz or more and 100 kHz or less. The reactor 1 of the embodiment is typically used in a component of a converter mounted on a vehicle such as an electric vehicle or a hybrid vehicle, or a component of a power conversion device having the converter.

[0078] like Figure 6 As shown, a vehicle 1200 such as a hybrid vehicle or an electric vehicle includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and an electric motor 1220 driven by the power supplied from the main battery 1210 and used for traveling. The electric motor 1220 is typically a three-phase AC electric motor, which drives wheels 1250 during traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 includes an engine 1300 in addition to the electric motor 1220. Figure 6 In FIG. 1 , a socket is shown as a charging portion of vehicle 1200 , but a plug may be provided.

[0079] The power conversion device 1100 includes a converter 1110 connected to a main battery 1210, and an inverter 1120 connected to the converter 1110 and performing mutual conversion between direct current and alternating current. The converter 1110 shown in this example boosts the input voltage of the main battery 1210 of about 200V to about 300V to about 400V to about 700V when the vehicle 1200 is running, and supplies power to the converter 1120. 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 during regeneration, and charges the main battery 1210. The input voltage is a DC voltage. The inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC when the vehicle 1200 is running, and supplies power to the motor 1220 by converting the AC output from the motor 1220 into a DC and outputting it to the converter 1110 during regeneration.

[0080] like Figure 7 As shown, the converter 1110 includes a plurality of switching elements 1111, a driving circuit 1112 for controlling the operation of the switching elements 1111, and a reactor 1115, and performs conversion of the input voltage by repeating ON / OFF (connection / disconnection). The conversion of the input voltage here is to perform step-up and step-down. The switching element 1111 uses power devices such as field effect transistors and insulated gate bipolar transistors. The reactor 1115 has the following function: utilizing the coil property of hindering the change of the current to be passed through the circuit, when the current is to be increased or decreased by the switching action, the change is smoothed. As the reactor 1115, the reactor 1 of the embodiment is provided.

[0081] In addition to the converter 1110, the vehicle 1200 is provided with a converter 1150 for a power supply device connected to the main battery 1210 and a converter 1160 for a power supply. The converter 1160 for a power supply device is connected to the sub-battery 1230 and the main battery 1210, which are power sources for the auxiliary machines 1240, and converts the high voltage of the main battery 1210 into a low voltage. The converter 1110 typically performs DC-DC conversion, but the converter 1150 for a power supply device and the converter 1160 for an auxiliary machine power supply perform AC-DC conversion. The converter 1150 for a power supply device also has a converter that performs DC-DC conversion. The reactors of the converter 1150 for a power supply device and the converter 1160 for an auxiliary machine power supply have the same structure as the reactor 1 of the embodiment, and the reactors with appropriately changed sizes, shapes, etc. can be used. In addition, the converter that converts the input power and the converter that only performs step-up or the converter that only performs step-down can also use the reactor 1 of the embodiment.

[0082] The converter 1110 and the power conversion device 1100 including the reactor 1 according to the embodiment having stable magnetic characteristics exhibit stable and excellent magnetic characteristics.

[0083] <Test Example 1> In Experimental Example 1, the effect of the first chip 5 having a partially different relative magnetic permeability on the performance of the reactor 1 was investigated. In this experiment, a test reactor including the first chip 5 and a test reactor including a chip made of a conventional composite material were prepared, and the inductances of the two test reactors were compared. Figure 4 Therefore, in the following description, reference will be made to the reactor 1 shown in FIG. Figure 4 Provide explanation.

[0084] 《Sample No. 1》 The split pieces 3A in the test reactor of sample number 1 are molded bodies of composite materials produced without applying a magnetic field during resin molding. The split pieces 3B in the test reactor of sample number 1 are powder compacts.

[0085] 《Sample No. 2》 The split piece 3A in the test reactor of sample number 2 is the first core piece 5 produced by resin molding while applying a magnetic field in the X direction. The split piece 3B in the test reactor of sample number 2 is a powder compact having the same structure as that of sample number 1.

[0086] The inductance of sample number 1 and sample number 2 were measured under the same measurement conditions. As a result, the inductance of sample number 2 was 6% higher than that of sample number 1. Therefore, it is known that the first core piece 5 containing the soft magnetic powder oriented in the X direction contributes to the improvement of the magnetic characteristics of the reactor 1.

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

[0088] By applying the magnetic field of the BH evaluation device to the Y direction of the first test piece, the relative magnetic permeability of the first part 51 in the Y direction is measured. Specifically, the first test piece is set in the BH evaluation device in such a way that the Y direction of the first test piece becomes the direction along the magnetic field of the BH evaluation device, and the relative magnetic permeability of the first test piece is measured. In addition, by applying the magnetic field of the BH evaluation device to the X direction of the second test piece, the relative magnetic permeability of the second part 52 in the X direction is measured. Specifically, the second test piece is set in the BH evaluation device in such a way that the X direction of the second test piece becomes the direction along the magnetic field of the BH evaluation device, and the relative magnetic permeability of the second test piece is measured. As a result, it can be seen that the relative magnetic permeability of the second part 52 in the X direction is higher than the relative magnetic permeability of the first part 51 in the Y direction. Description of Reference Numerals

[0089] 1 Reactor 2 Coils 21, 22 Winding section 3 Magnetic core 3a first end surface, 3b second end surface, 3g gap 3A, 3B, 3C, 3D split pieces 30 middle core, 31 first end core, 32 second end core 33 first side core, 34 second side core 35, 36 inner core, 37, 38 outer core 5First Chip 51 Part 1, 52 Part 2 6 Second chip 9 Composite Materials 90 resin, 91 soft magnetic powder 1100 Power conversion device 1110 converter, 1111 switch element, 1112 drive circuit 1115 Reactor, 1120 Inverter 1150 Converter for power supply device, 1160 Converter for auxiliary power supply 1200 vehicles 1210 main battery, 1220 electric motor, 1230 auxiliary battery 1240 auxiliary machinery, 1250 wheels 1300 Engine L, T0, T1, T2, T3, T4 length WWidth

Claims

1. A reactor comprising a coil and a magnetic core, wherein the coil has a winding portion, The magnetic core has a plurality of divided pieces including a first core piece, The first chip is composed of a composite material containing a resin and a soft magnetic powder dispersed in the resin, and the first chip includes a first part and a second part. The first portion extends in a direction perpendicular to the axial direction of the winding portion and is arranged at a position facing the end surface of the winding portion. The second portion extends from the first portion along the axis direction, The first part and the second part are continuously formed without a joint, A first relative magnetic permeability of the first portion with respect to a magnetic flux along an extending direction of the first portion is different from a second relative magnetic permeability of the second portion with respect to a magnetic flux along an extending direction of the second portion.

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

3. The reactor according to claim 1 or claim 2, wherein: The first chip is in an E-shape having a base and three legs extending from the base. The base is the first part, The three legs are respectively the second parts.

4. The reactor according to any one of claims 1 to 3, wherein: The magnetic core is composed of the first chip and a second chip, and the second chip has the same structure as the first chip.

5. A split piece constituting a part of a magnetic core provided in a reactor, The split piece is composed of a composite material containing a resin and a soft magnetic powder dispersed in the resin. The split piece comprises a first part and a second part. The second portion extends in a direction orthogonal to an extending direction of the first portion, The first part and the second part are continuously formed without a joint, A first relative magnetic permeability of the first portion with respect to a magnetic flux along an extending direction of the first portion is different from a second relative magnetic permeability of the second portion with respect to a magnetic flux along an extending direction of the second portion. 6 . A converter comprising the reactor according to claim 1 .

7. A power conversion device comprising the converter according to claim 6.

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