Reactor, converter, and power conversion device

Abstract

An electric reactor has a coil and a magnetic core. The coil has a winding portion. The number of winding portions is one. The shape of the winding portion is rectangular tube shape. The magnetic core is a combination of a first core portion and a second core portion. The first core portion and the second core portion are formed of shaped bodies of mutually different materials.

Description

Technical Field

[0001] This disclosure relates to reactors, converters, and power conversion devices.

[0002] This application claims priority based on Japanese Patent Application No. 2020-035394 filed on March 2, 2020, and incorporates all the contents of the Japanese application. Background Technology

[0003] Patent Document 1 describes a reactor comprising a coil, a magnetic core, a housing, and a cooling pipe. The coil is constructed by winding a wire into a spiral shape. There is one coil, and the coil is cylindrical in shape. The magnetic core has an inner core and an outer core. The inner core is disposed inside the coil. The outer core covers the two end faces of the inner core, the two end faces of the coil, and the outer peripheral surface. The inner and outer cores are made of different materials. Specifically, the inner core is made of a pressed powder molded body, and the outer core is made of a molded composite material. The housing houses the assembly of the coil and the magnetic core. By arranging the coil and the inner core inside the housing, filling the housing with the raw material of the composite material and allowing it to solidify, the assembly can be housed within the housing. Refrigerant flows inside the cooling pipe. The cooling pipe is wound into a spiral shape circumferentially around the housing in contact with the outer peripheral surface of the housing.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-74062 Summary of the Invention

[0007] The reactor disclosed herein includes a coil and a magnetic core. The coil has a winding portion, the number of which is one, and the winding portion is rectangular cylindrical in shape. The magnetic core is a composition formed by combining a first core portion and a second core portion, the first core portion and the second core portion being formed from molded bodies of different materials.

[0008] The converter disclosed herein incorporates the reactor disclosed herein.

[0009] The power conversion device disclosed herein includes the converter disclosed herein. Attached Figure Description

[0010] Figure 1 This is a perspective view showing the overall outline of the reactor according to Embodiment 1.

[0011] Figure 2 This is a perspective view showing the general state of the reactor in Embodiment 1 when disassembled.

[0012] Figure 3This is a top view showing the overall outline of the reactor in Embodiment 1.

[0013] Figure 4 This is a top view showing the overall outline of the reactor in Embodiment 2.

[0014] Figure 5 This is a top view showing the overall outline of the reactor in Embodiment 3.

[0015] Figure 6 This is a top view showing the overall outline of the reactor in Embodiment 4.

[0016] Figure 7 This is a schematic diagram illustrating the power system configuration of a hybrid electric vehicle.

[0017] Figure 8 This is a schematic circuit diagram showing an example of a power conversion device equipped with a converter. Detailed Implementation

[0018] [The problem this disclosure aims to solve]

[0019] The aforementioned assembly, by using different materials for its inner and outer cores, facilitates inductance adjustment. However, because the coil and inner core are embedded in the outer core, heat dissipation is difficult to adjust. This is because the surface of the assembly is essentially made only of the material used in the outer core. Consequently, the assembly exhibits low heat dissipation. This is because the outer core is made of a composite material with relatively low thermal conductivity. Therefore, the aforementioned reactor improves heat dissipation by housing the assembly within a casing with a cooling tube wound around it. However, the reactor becomes larger by winding a cooling tube around the casing.

[0020] One objective of this disclosure is to provide a reactor that does not require large-scale manufacturing and whose inductance and heat dissipation are easily adjustable. Another objective is to provide a converter incorporating the aforementioned reactor. Furthermore, another objective is to provide a power conversion device incorporating the aforementioned converter.

[0021] [The Effects of This Disclosure]

[0022] The reactor disclosed herein does not require large size and is easy to adjust in terms of inductance and heat dissipation.

[0023] The converter and power conversion device disclosed herein will not be large in size and have excellent heat dissipation.

[0024] Description of Implementation Methods of this Disclosure

[0025] First, the implementation methods of this disclosure are listed and explained.

[0026] (1) A reactor according to one aspect of the present disclosure has a coil and a magnetic core, the coil having a winding portion, the number of the winding portions being one, the winding portion being rectangular cylindrical in shape, and the magnetic core being a composition of a first core portion and a second core portion, the first core portion and the second core portion being formed of molded bodies of different materials.

[0027] The aforementioned reactor allows for easy inductance adjustment. In particular, the reactor does not have a large gap between the first and second cores, facilitating inductance adjustment. This is because the magnetic core is not made of a single material, but rather consists of a first core and a second core made of different shaped materials.

[0028] The aforementioned reactor offers easier heat dissipation adjustment compared to existing reactors. Existing reactors are constructed by embedding a core with higher thermal conductivity within a core with lower thermal conductivity. This means the surface of the core is made of a single material. In contrast, the aforementioned reactor, by using molded bodies of different materials for the first and second core portions, allows for the use of different materials for the core surface.

[0029] The above-described reactor offers improved heat dissipation compared to existing reactors. The surface of the magnetic core in existing reactors, as described above, is composed solely of a core with relatively low thermal conductivity. This is because, in contrast, the above-described reactor allows for the construction of the magnetic core surface from different materials, as described above, enabling the core surface to include a surface made of a material with excellent heat dissipation.

[0030] The aforementioned reactor can be appropriately used in reactors cooled by cooling components with uneven cooling performance. The core with higher heat dissipation performance is positioned on the side of the cooling component with lower cooling performance, and the core with lower heat dissipation performance is positioned on the side with higher cooling performance. As a result, the first and second cores are cooled uniformly, and the maximum temperature of the magnetic core is reduced. Thus, because the maximum temperature of the magnetic core is reduced, the aforementioned reactor has low losses.

[0031] The aforementioned reactor is not easily made large-scale because: as described above, the heat dissipation of the aforementioned reactor is easily adjusted and improved, therefore, it is not necessary to install cooling pipes as in existing reactors.

[0032] The reactor described above has only one winding section, which reduces the installation area in the parallel direction compared to the case where multiple winding sections are arranged side by side in a direction orthogonal to the axial direction of the winding sections.

[0033] Because the winding section of the aforementioned reactor is rectangular, it is easier to increase the contact area with the object being installed compared to a cylindrical winding section with the same cross-sectional area. Therefore, the aforementioned reactor can easily dissipate heat to the object through the winding section. Furthermore, the winding section of the aforementioned reactor can be stably positioned on the object.

[0034] The reactor described above is easier to manufacture than the existing reactors described above. The existing reactors are manufactured by filling a composite material into a composition consisting of a coil and an intermediate core, and then curing it. In this case, the composite material needs to be fully distributed around the outer periphery of the composition, making it difficult to manufacture the side cores. In contrast, the reactor described above only requires assembling pre-made first and second cores into the coil. Since the first and second cores do not fill the coil or other cores, they are easier to manufacture.

[0035] (2) As one method of the above-mentioned reactor, the relative permeability of the first core is less than that of the second core.

[0036] The aforementioned reactor satisfies the aforementioned relative permeability relationship between the first and second cores, thus eliminating a large gap between them and facilitating inductance adjustment. Furthermore, the absence of a large gap between the first and second cores also reduces eddy current losses generated in the winding section due to leakage flux.

[0037] (3) As one type of reactor as described in (2) above, the first core has a relative permeability of 50 or less, and the second core has a relative permeability of 50 or more.

[0038] The inductance of the aforementioned reactor can be easily adjusted.

[0039] (4) As one method of the above-mentioned reactor, the following methods can be listed: the iron loss of the second core is greater than that of the first core, and the thermal conductivity of the second core is greater than that of the first core.

[0040] The aforementioned reactor achieves its temperature resistance by satisfying the above-mentioned relationship between iron loss and thermal conductivity. This is because: although the second core has high iron loss and is prone to overheating, it also has high thermal conductivity and excellent heat dissipation; while the first core has low thermal conductivity and poor heat dissipation, it has low iron loss and is less prone to overheating.

[0041] (5) As one embodiment of the above-mentioned reactor, the first core is composed of a molded body of a composite material in which soft magnetic powder is dispersed in a resin, and the second core is composed of a pressed powder molded body containing soft magnetic powder.

[0042] The aforementioned reactor features a first core constructed from a molded composite material and a second core constructed from pressed powder. This design minimizes the gap between the first and second cores, facilitating easy adjustment of inductance and heat dissipation. Furthermore, the second core's high thermal conductivity further enhances heat dissipation.

[0043] (6) As one embodiment of the reactor described in (5) above, the magnetic core may include: a first end chip and a second end chip facing each end face of the winding portion; an intermediate core having a portion disposed inside the winding portion; and a first side core and a second side core disposed on the outer periphery of the winding portion, separated from the intermediate core, wherein the first core and the second core are combined in the axial direction of the winding portion, wherein the first core has: a first end chip; and at least one selected from the group consisting of at least a portion of the intermediate core, at least a portion of the first side core, and at least a portion of the second side core, wherein the second core has at least a second end chip selected from the group consisting of a second end chip, the remaining portion of the intermediate core, the remaining portion of the first side core, and the remaining portion of the second side core.

[0044] The aforementioned reactor further facilitates adjustment of inductance and heat dissipation. Furthermore, the reactor can be constructed by combining the first core and the second core relative to the winding portion along the axial direction of the winding portion, thus offering excellent manufacturability.

[0045] (7) As one embodiment of the reactor described in (6) above, the second core has at least one portion selected from the group consisting of the remaining portion of the intermediate core, the remaining portion of the first side core, and the remaining portion of the second side core. The length L1 of the remaining portion of the intermediate core, the length L21 of the remaining portion of the first side core, and the length L22 of the remaining portion of the second side core are less than twice the length L3 of the second end chip. The length L1 of the remaining portion of the intermediate core is the length of the remaining portion of the intermediate core along the axial direction of the winding portion. The length L21 of the remaining portion of the first side core is the length of the remaining portion of the first side core along the axial direction of the winding portion. The length L22 of the remaining portion of the second side core is the length of the remaining portion of the second side core along the axial direction of the winding portion. The length L3 of the second end chip is the length of the second end chip along the axial direction of the winding portion.

[0046] In the aforementioned reactor, the density deviations of the second intermediate chip, the first side chip, the second side chip, and the second end chip are easily reduced. The reason is as follows: The powder compaction body is constructed by compressing raw material powder. The direction of pressure application during molding depends on the shape and size of the powder compaction body, but in most cases it is along the axial direction of the second intermediate chip. When the lengths L1, L21, and L22 are less than twice the length L3, it is easier to reduce the deviation of the pressure acting on each chip during the molding of the second core. Therefore, it is easier to manufacture a second core with small density deviations.

[0047] (8) As one embodiment of the reactor described in (6) above, the second core has at least one portion selected from the group consisting of the remaining portion of the intermediate core, the remaining portion of the first side core, and the remaining portion of the second side core. The length L1 of the remaining portion of the intermediate core, the length L21 of the remaining portion of the first side core, and the length L22 of the remaining portion of the second side core exceed twice the length L3 of the second end chip. The length L1 of the remaining portion of the intermediate core is the length of the remaining portion of the intermediate core along the axial direction of the winding portion. The length L21 of the remaining portion of the first side core is the length of the remaining portion of the first side core along the axial direction of the winding portion. The length L22 of the remaining portion of the second side core is the length of the remaining portion of the second side core along the axial direction of the winding portion. The length L3 of the second end chip is the length of the second end chip along the axial direction of the winding portion.

[0048] The aforementioned reactor facilitates improved heat dissipation. This is because, since the lengths L1, L21, and L22 exceed twice the length L3, it is easier to increase the proportion of the second core, which is composed of a powder-formed body with relatively high thermal conductivity, within the magnetic core. Sometimes, the pressing direction during forming is not along the axial direction of each intermediate chip, but rather a direction orthogonal to both the axial direction of each intermediate chip and the parallel direction of the two side chips. In this case, it is also possible to form a second core with lengths L1, L21, and L22 exceeding twice the length L3. Furthermore, when the pressing direction during forming is the aforementioned orthogonal direction, it is easier to incorporate cutouts and chamfers into the second core during forming.

[0049] (9) As one form of reactor of any of (6) to (8) above, the shape of the first core and the shape of the second core are asymmetrical.

[0050] The reactor described above has an asymmetrical shape for the first core and the second core, thereby expanding the options for the shape of the first core and the second core.

[0051] (10) As one embodiment of the reactor described in any of (6) to (9) above, the magnetic core has a gap portion disposed between the first core portion and the second core portion.

[0052] The gap portion is disposed inside the winding portion.

[0053] The reactor described above is disposed inside the winding section through a gap, which makes it easier to reduce the eddy current loss generated in the winding section due to leakage flux intrusion compared to the case where it is disposed outside the winding section.

[0054] (11) As one type of reactor as described in (10) above, the length of the gap portion along the axial direction of the winding portion is 2 mm or less.

[0055] The aforementioned reactors have low leakage flux, making it easier to increase the reduction effect of eddy current losses.

[0056] (12) A converter of one aspect of the present disclosure includes any one of the reactors described in (1) to (11) above.

[0057] Because the aforementioned converter incorporates the reactor, it does not require a large size and has excellent heat dissipation.

[0058] (13) One aspect of the power conversion device of the present disclosure includes the converter described in (12).

[0059] The aforementioned power conversion device has the aforementioned converter, therefore it will not be large in size and has excellent heat dissipation.

[0060] Details of the embodiments disclosed herein

[0061] The following is a reference to the appendix. Figure 1 The details of embodiments of this disclosure will be described below. The same reference numerals in the figures denote the same names of objects.

[0062] Implementation Method 1

[0063] [Reactor]

[0064] Reference Figures 1 to 3 The reactor 1 of embodiment 1 is described below. The reactor 1 includes a coil 2 and a magnetic core 3. The coil 2 has a winding portion 21. One feature of the reactor 1 of this embodiment is that it satisfies the following requirements (a) to (c).

[0065] (a) The number of winding portions 21 is a specific number, and the shape of the winding portions 21 is a specific shape.

[0066] (b) The magnetic core 3 is a composition consisting of a first core 3f and a second core 3s.

[0067] (c) The first core 3f and the second core 3s are formed from molded bodies made of different materials.

[0068] The following details each structure. For ease of explanation, Figure 3 Coil 2 is shown with a double-dotted line. This is true even when referring to embodiments 2 to 4 described later. Figures 4 to 6 The same applies.

[0069] [coil]

[0070] like Figure 1 , Figure 2 As shown, the coil 2 has a hollow winding portion 21. The number of winding portions 21 is one. In this type of reactor 1, because the number of winding portions 21 is one, the length along the second direction D2, which will be described later, can be shortened compared to the case where multiple winding portions are arranged side by side in a direction orthogonal to the axial direction of the winding portions.

[0071] like Figure 2 As shown, the winding portion 21 is rectangular cylindrical in shape. The rectangle includes a square. That is, the end face of the winding portion 21 is formed into a rectangular frame shape. Because the winding portion 21 is rectangular cylindrical, compared to a cylindrical winding portion with the same cross-sectional area, it is easier to increase the contact area between the winding portion 21 and the object being installed. Therefore, the reactor 1 can easily dissipate heat to the object being installed through the winding portion 21. Based on this, it is easier to stably install the winding portion 21 on the object being installed. The corners of the winding portion 21 are rounded.

[0072] The winding section 21 is constructed by winding a single wire without joints into a spiral shape. Known winding materials can be used. In this method, a coated flat wire is used. The conductor wire of the coated flat wire is made of copper flat wire. The insulating coating of the coated flat wire is made of enamel. The winding section 21 is constructed from a flat, upright coil obtained by flattening and vertically winding the coated flat wire.

[0073] In this embodiment, one end 21a and the other end 21b of the winding portion 21 extend outwards from one end side and the other end side in the axial direction of the winding portion 21, respectively. Although not shown in the figure, the insulating covering of one end 21a and the other end 21b of the winding portion 21 is peeled off to expose the conductor wire. A terminal member is connected to the exposed conductor wire. The terminal member is not shown in the figure. An external device is connected to the coil 2 through this terminal member. The external device is not shown in the figure. Examples of external devices include a power supply that supplies power to the coil 2.

[0074] [Magnetic Core]

[0075] like Figure 1As shown, the magnetic core 3 has a first end chip 33f and a second end chip 33s, a middle core 31, a first side core 321 and a second side core 322. In the magnetic core 3, the direction along the axial direction of the winding portion 21 is designated as the first direction D1, the parallel direction of the middle core 31, the first side core 321 and the second side core 322 is designated as the second direction D2, and the direction orthogonal to both the first direction D1 and the second direction D2 is designated as the third direction D3.

[0076] (First-end chip · Second-end chip)

[0077] The first chip 33f faces one end face of the winding portion 21. The second chip 33s faces the other end face of the winding portion 21. "Facing" means that the end faces of the chip and the winding portion 21 are opposite to each other. The shapes of the first chip 33f and the second chip 33s are as follows: Figure 1 , Figure 2 The shapes shown are the same, and are thin prismatic.

[0078] (Middle core)

[0079] The intermediate core 31 has a portion disposed inside the winding portion 21. The shape of the intermediate core 31 can be, for example, a shape corresponding to the inner circumferential shape of the winding portion 21. In this embodiment, such as... Figure 2 As shown, it is a quadrangular prism. The corners of the central core 31 can also be rounded along the inner circumferential surface of the corner of the winding portion 21.

[0080] like Figure 3 As shown, the length of the intermediate core 31 along the first direction D1 is equal to the length of the winding portion 21 along the axial direction. The length of the intermediate core 31 along the first direction D1 refers to the total length (L1f + L1s) of the first intermediate chip 31f and the second intermediate chip 31s, described later. The length of the intermediate core 31 along the first direction D1 does not include the length Lg of the gap portion 3g, described later, along the first direction D1. The same meaning applies to the lengths of other cores and chips.

[0081] In this embodiment, the length of the intermediate core 31 along the first direction D1 is shorter than the length of the first side core 321 along the first direction D1 and the length of the second side core 322 along the first direction D1. The length of the first side core 321 along the first direction D1 refers to the total length (L21f + L21s) of the lengths of the first side chip 321f and the first side chip 321s, described later. The length of the second side core 322 along the first direction D1 refers to the total length (L22f + L22s) of the lengths of the second side chip 322f and the second side chip 322s, described later. Alternatively, the length of the intermediate core 31 along the first direction D1 may differ from this embodiment and may be equal to the length of the first side core 321 and the second side core 322 along the first direction D1.

[0082] Regarding the intermediate core 31, examples include the following: as in this method or reference Figure 5 The case where it is composed of two chips, a first intermediate chip 31f and a second intermediate chip 31s, as described in Embodiment 3 below; and as referred to Figure 4 The following is an implementation method 2 or reference. Figure 6 The case where it is composed of a first intermediate chip 31f, as described in the following implementation method 4.

[0083] (First side core, second side core)

[0084] like Figure 1 , Figure 2 As shown, the first side core 321 and the second side core 322 are arranged opposite to each other with a gap between them and the intermediate core 31. The first side core 321 and the second side core 322 are disposed on the outer periphery of the winding portion 21. The shape of the first side core 321 and the shape of the second side core 322 are the same, which are thin prismatic shapes.

[0085] like Figure 3 As shown, the length of the first side core 321 along the first direction D1 (L21f+L21s) and the length of the second side core 322 along the first direction D1 (L22f+L22s) are longer than the length of the winding portion 21 along the axial direction. Furthermore, the lengths of the first side core 321 and the second side core 322 along the first direction D1 can be equal to the length of the winding portion 21 along the axial direction.

[0086] Regarding the first side core 321, examples include: the case where it is composed of two chips, first side chip 321f and first side chip 321s, as in this method or embodiment 4; and the case where it is composed of one first side chip 321f, as in embodiment 2 or embodiment 3.

[0087] Regarding the second side core 322, examples include: the case where it is composed of two chips, the second side chip 322f and the second side chip 322s, as in this embodiment or embodiment 4; and the case where it is composed of a single second side chip 322f, as in embodiment 2 or embodiment 3.

[0088] In this configuration, the sum of the cross-sectional areas of the first side core 321 and the second side core 322 is the same as the cross-sectional area of ​​the intermediate core 31. That is, the sum of the length of the first side core 321 along the second direction D2 and the length of the second side core 322 along the second direction D2 is equivalent to the length of the intermediate core 31 along the second direction D2.

[0089] The magnetic core 3 is a composite material consisting of a first core portion 3f and a second core portion 3s. The combination of the first core portion 3f and the second core portion 3s can be configured in various ways by appropriately selecting the shapes of the first core portion 3f and the second core portion 3s. The shapes of the first core portion 3f and the second core portion 3s can be symmetrical, but are preferably asymmetrical. Symmetry means that the shapes and dimensions are the same. Asymmetry means that the shapes are different. By being asymmetrical, the selection of the shapes of the first core portion 3f and the second core portion 3s can be expanded. In this embodiment, the shapes of the first core portion 3f and the second core portion 3s are asymmetrical.

[0090] In this method, the first core 3f and the second core 3s are as follows: Figure 2 The circuit is divided in the first direction D1. The combination of the first core 3f and the second core 3s is configured as EE type in this embodiment. Alternatively, the combination can be configured as EI type as in Embodiment 2. Furthermore, the combination can be configured as ET type as in Embodiment 3. And, the combination can be configured as EU type as in Embodiment 4. In addition, although not shown in the figure, the combination can also be configured as FF type, FL type, UT type, etc. When configured as these combinations, it is easier to adjust the inductance and heat dissipation. Furthermore, since the reactor 1 can be constructed by combining the first core 3f and the second core 3s along the axial direction of the winding section 21, it has excellent manufacturability.

[0091] The gap 3g, which will be described later, may be provided between the first core 3f and the second core 3s, or the gap 3g may not be provided.

[0092] (First Core)

[0093] The first core portion 3f may include at least a first end chip 33f. In addition to the first end chip 33f, the first core portion 3f may include at least one of the group consisting of at least a portion of the intermediate core portion 31, at least a portion of the first side core portion 321, and at least a portion of the second side core portion 322.

[0094] For example, when the first core portion 3f has at least a portion of a first end chip 33f and a middle core portion 31, the shape of the first core portion 3f is T-shaped. When the first core portion 3f has at least a portion of a first end chip 33f, a first side core portion 321, or a second side core portion 322, the shape of the first core portion 3f is L-shaped. When the first core portion 3f has at least a portion of a first end chip 33f, a middle core portion 31, and at least a portion of a first side core portion 321 or a second side core portion 322, the shape of the first core portion 3f is F-shaped. When the first core portion 3f has at least a portion of a first end chip 33f, a first side core portion 321, and a second side core portion 322, the shape of the first core portion 3f is U-shaped. When the first core 3f has at least a first end chip 33f, at least a portion of the middle core 31, at least a portion of the first side core 321 and at least a portion of the second side core 322, the shape of the first core 3f is E-shaped.

[0095] The first core 3f of this embodiment is E-shaped. That is, the first core 3f of this embodiment has a first end chip 33f, at least a portion of the middle core 31, at least a portion of the first side core 321, and at least a portion of the second side core 322. More specifically, the first core 3f of this embodiment has a first end chip 33f, a portion of the middle core 31, a portion of the first side core 321, and a portion of the second side core 322. More specifically, the first core 3f of this embodiment has a first end chip 33f, a first middle chip 31f, a first side chip 321f, and a second side chip 322f.

[0096] The first core 3f is a molded body integrally formed of a first end chip 33f, a first intermediate chip 31f, a first side chip 321f, and a second side chip 322f. The first end chip 33f connects the first intermediate chip 31f, the first side chip 321f, and the second side chip 322f. The first side chip 321f and the second side chip 322f are disposed at both ends of the first end chip 33f. The first intermediate chip 31f is disposed in the center of the first end chip 33f. The shape of the first end chip 33f, as described above, is a thin prism. The shape of the first intermediate chip 31f is a quadrangular prism. The shapes of the first side chip 321f and the second side chip 322f are thin prisms.

[0097] (Second Core)

[0098] The second core 3s, like the first core 3f, has at least a second end chip 33s. Depending on the combination of the first core 3f and the second core 3s, the second core 3s may, in addition to the second end chip 33s, have at least one of the following groups: the remaining portion of the intermediate core 31, the remaining portion of the first side core 321, and the remaining portion of the second side core 322.

[0099] For example, when the second core 3s is composed of a second end chip 33s, the shape of the second core 3s is I-shaped. When the second core 3s has the second end chip 33s and the remainder of the middle core 31, the shape of the second core 3s is T-shaped. When the second core 3s has the second end chip 33s and the remainder of either the first side core 321 or the second side core 322, the shape of the second core 3s is L-shaped. When the second core 3s has the second end chip 33s, the remainder of the middle core 31, and the remainder of either the first side core 321 or the second side core 322, the shape of the second core 3s is F-shaped. When the second core 3s has the second end chip 33s, the remainder of the first side core 321, and the remainder of the second side core 322, the shape of the second core 3s is U-shaped. When the second core 3s has a second end chip 33s, the remainder of the middle core 31, the remainder of the first side core 321 and the remainder of the second side core 322, the shape of the second core 3s is E-shaped.

[0100] The second core 3s in this embodiment is E-shaped. That is, the second core 3s in this embodiment has a second end chip 33s, the remainder of the middle core 31, the remainder of the first side core 321, and the remainder of the second side core 322. Specifically, the second core 3s in this embodiment has a second end chip 33s, a second middle chip 31s, a first side chip 321s, and a second side chip 322s.

[0101] The second core 3s is a molded body consisting of a second end chip 33s, a second intermediate chip 31s, a first side chip 321s, and a second side chip 322s. The second end chip 33s connects the second intermediate chip 31s, the first side chip 321s, and the second side chip 322s.

[0102] The first side chip 321s and the second side chip 322s are disposed at both ends of the second end chip 33s. The second intermediate chip 31s is disposed at the center of the second end chip 33s. The second end chip 33s is, as described above, a thin prismatic shape. The second intermediate chip 31s is a tetragonal prism shape. The first side chip 321s and the second side chip 322s are both thin prismatic shapes.

[0103] (size)

[0104] The dimensions of the first core 3f and the second core 3s are different. Specifically, there are portions where the lengths of each chip in the first core 3f along the first direction D1 differ from the lengths of each chip in the second core 3s along the first direction D1. The lengths of each chip in the first core 3f along the second direction D2 are the same as the lengths of each chip in the second core 3s along the second direction D2. The lengths of each chip in the first core 3f along the third direction D3 are the same as the lengths of each chip in the second core 3s along the third direction D3.

[0105] In the first core 3f, the lengths L1f along the first direction D1 of the first intermediate chip 31f, L21f along the first direction D1 of the first side chip 321f, and L22f along the first direction D1 of the second side chip 322f can be either at least one different or all the same. In this embodiment, the lengths L21f and L22f are the same, and L21f is longer than L1f. Alternatively, in the first core 3f, the lengths L21f and L22f can be the same, and L1f can be longer than both L21f and L22f.

[0106] In the second core 3s, the lengths L1s of the second intermediate chip 31s along the first direction D1, L21s of the first side chip 321s along the first direction D1, and L22s of the second side chip 322s along the first direction D1 can be at least one different, or all the lengths can be the same. In this embodiment, the lengths L21s and L22s are the same, and longer than the length L1s. Alternatively, in the second core 3s, the lengths L21s and L22s can also be the same, and the length L1s can be longer than both L21s and L22s.

[0107] The aforementioned lengths L1f and L1s can be different as in this method, or they can be the same as in this method. In this method, the aforementioned length L1f is longer than the aforementioned length L1s.

[0108] The lengths of the first intermediate chip 31f along the second direction D2 and the second intermediate chip 31s along the second direction D2 are the same as described above. The lengths of the first intermediate chip 31f along the third direction D3 and the second intermediate chip 31s along the third direction D3 are the same as described above.

[0109] The aforementioned lengths L21f and L21s can be different as in this method, or they can be the same as in this method. In this method, the aforementioned length L21f is longer than the aforementioned length L21s.

[0110] The lengths of the first side chip 321f of the first core 3f along the second direction D2 and the lengths of the first side chip 321s of the second core 3s along the second direction D2 are the same as described above. The lengths of the first side chip 321f of the first core 3f along the third direction D3 and the lengths of the first side chip 321s of the second core 3s along the third direction D3 are the same as described above.

[0111] The lengths L22f and L22s mentioned above can be different as in this embodiment, or they can be the same as in this embodiment. In this embodiment, the length L22f is longer than the length L22s. The length of the second side chip 322f of the first core 3f along the second direction D2 and the length of the second side chip 322s of the second core 3s along the second direction D2 are the same as described above. The length of the second side chip 322f of the first core 3f along the third direction D3 and the length of the second side chip 322s of the second core 3s along the third direction D3 are the same as described above.

[0112] The length L3f of the first chip 33f along the first direction D1 and the length L3s of the second chip 33s along the first direction D1 are as follows: Figure 3 The images shown are identical to each other.

[0113] The length of the first chip 33f along the second direction D2 and the length of the second chip 33s along the second direction D2 are as follows: Figure 3 The lengths shown are the same as those shown, and are longer than the length of the winding portion 21 along the second direction D2.

[0114] The length of the first chip 33f along the third direction D3 and the length of the second chip 33s along the third direction D3 are as follows: Figure 1 The lengths shown are the same as each other and are smaller than the length of the winding portion 21 along the third direction D3. The lengths of the first end chip 33f and the second end chip 33s along the third direction D3 can be either longer than or the same as the length of the winding portion 21 along the third direction D3.

[0115] In this embodiment, as described later, the second core 3s is formed by a powder-pressed molding body. When formed by a powder-pressed molding body, the lengths L1s, L21s, and L22s can be less than or more than twice the length L3s. The powder-pressed molding body is formed by compressing raw material powder. While the direction of pressure during molding depends on the shape and size of the powder-pressed molding body, examples include directions along the first direction D1 or along the third direction D3.

[0116] When the pressure direction during molding is along the first direction D1, if the lengths L1s, L21s, and L22s are less than twice the length L3s, then the deviation in pressure acting on each chip is easily reduced during the molding of the second core 3s. Therefore, the deviations in the density of the second intermediate chip 31s, the density of the first side chip 321s, the density of the second side chip 322s, and the density of the second end chip 33s are easily reduced. When the pressure direction during molding is along the first direction D1, the lengths L1s, L21s, and L22s are more preferably less than 1.8 times the length L3s, and particularly preferably less than 1.6 times. For example, the lengths L1s, L21s, and L22s can be more than one time the length L3s.

[0117] When the pressing direction during molding is along the third direction D3, it is not only possible to manufacture a second core 3s whose lengths L1s, L21s, and L22s are less than twice the length L3s, but also more than twice the length L3s. When the lengths L1s, L21s, and L22s exceed twice the length L3s, it is easier to increase the proportion of the second core 3s composed of a pressed powder body with relatively high thermal conductivity in the magnetic core 3, thus improving the heat dissipation of the reactor 1. Furthermore, when the pressing direction during molding is along the third direction D3, compared to when the pressing direction during molding is along the first direction D1, it is easier to provide cut-out portions and chamfered portions in the second core 3s during molding. When the pressing direction during molding is along the third direction D3, the lengths L1s, L21s, and L22s can further exceed 2.5 times, and particularly more than 3 times, the length L3s. The lengths L1s, L21s, and L22s mentioned above can be, for example, less than 5 times the length L3s mentioned above.

[0118] In this method, the lengths L1s, L21s, and L22s are less than twice the length L3s.

[0119] The first core 3f and the second core 3s are combined such that the end faces of the first side chip 321f and the second side chip 322f of the first core 3f are respectively in contact with the end faces of the first side chip 321s and the second side chip 322s of the second core 3s. When combined in this way, because the aforementioned length relationship is satisfied, a gap is provided between the end face of the first intermediate chip 31f of the first core 3f and the end face of the second end chip 33s of the second core 3s. The length of this gap along the first direction D1 corresponds to the length Lg of the gap portion 3g.

[0120] Of course, the first core 3f and the second core 3s can also be combined such that a gap is provided between the end face of the first side chip 321f and the end face of the second side chip 322f of the first core 3f and the end face of the first side chip 321s and the end face of the second side chip 322s of the second core 3s. When combined in this way, because the above-mentioned length relationship is satisfied, a gap is also provided between the end face of the first intermediate chip 31f and the end face of the second intermediate chip 31s. The gap between the end face of the first intermediate chip 31f and the end face of the second intermediate chip 31s is larger than the gap between the end faces of the first side chip 321f and the first side chip 321s, and the gap between the end faces of the second side chip 322f and the second side chip 322s. In this case, the first core 3f and the second core 3s can be combined simply by using the molding resin part, etc., as described later. The gap is formed by filling the molding resin part into the above-mentioned gap.

[0121] (Relationship between relative permeability)

[0122] Preferably, the relative permeability of the first core 3f and the second core 3s satisfies the condition that the relative permeability of the first core 3f is less than that of the second core 3s. By satisfying this relative permeability relationship between the first core 3f and the second core 3s, the reactor 1 avoids a large gap 3g between them, facilitating inductance adjustment. Furthermore, the reactor 1 can also avoid a long gap 3g of length Lg between the first core 3f and the second core 3s, thus easily reducing eddy current losses generated in the winding section 21 due to leakage flux intrusion. The long gap 3g of length Lg refers, for example, to a length exceeding 2 mm.

[0123] Based on satisfying the aforementioned relative permeability relationship, the relative permeability of the first core 3f is preferably 50 or less, and the relative permeability of the second core 3s is preferably 50 or more. This is because it facilitates inductance adjustment. The relative permeability of the first core 3f is further preferably 45 or less, 40 or less, and particularly 30 or less. For example, the relative permeability of the first core 3f can be 5 or more, and further 15 or more. The relative permeability of the second core 3s is further preferably 100 or more, and particularly preferably 150 or more. The relative permeability of the second core 3s can be, for example, 500 or less, and further 300 or less.

[0124] (The relationship between iron loss and thermal conductivity)

[0125] The first core 3f and the second core 3s preferably satisfy the following conditions: "the iron loss of the first core 3f < the iron loss of the second core 3s" and "the thermal conductivity of the first core 3f < the thermal conductivity of the second core 3s". By satisfying this relationship, the temperature of the reactor 1 is less likely to rise. This is because: although the second core 3s has a large iron loss and is prone to heat generation, it also has a high thermal conductivity and excellent heat dissipation; while the first core 3f has a low thermal conductivity and poor heat dissipation, it has a small iron loss and is less prone to heat generation.

[0126] The difference in thermal conductivity between the first core 3f and the second core 3s is preferably 1 W / m·K or higher, more preferably 3 W / m·K or higher, and particularly preferably 5 W / m·K or higher. The difference in thermal conductivity can be, for example, 20 W / m·K or lower. The thermal conductivity of the first core 3f is preferably 1 W / m·K or higher, more preferably 2 W / m·K or higher, and particularly preferably 3 W / m·K or higher. In practical applications, the thermal conductivity of the first core 3f can be, for example, 5 W / m·K or lower. The thermal conductivity of the second core 3s is preferably 5 W / m·K or higher, more preferably 10 W / m·K or higher, and particularly preferably 15 W / m·K or higher. In practical applications, the thermal conductivity of the second core 3s can be, for example, 20 W / m·K or lower.

[0127] The relative permeability is determined as follows. Ring-shaped test specimens are cut from both the first and second cores. Each test specimen is wound with 300 turns on the primary side and 20 turns on the secondary side. The initial magnetization curve of BH is measured within the range of H = 0 (Oe) to 100 (Oe), and the maximum slope of this initial magnetization curve is determined. This maximum value is set as the relative permeability. Furthermore, the magnetization curve here is a so-called DC magnetization curve.

[0128] The iron loss was calculated using the aforementioned test samples as follows. Using a BH waveform recorder, the iron loss (W / m³) was measured at an excitation magnetic flux density of Bm: 1 kG (=0.1 T) and a measurement frequency of 10 kHz.

[0129] Thermal conductivity was determined by measuring the first and second cores separately using the temperature gradient method and the laser flash method.

[0130] (Material)

[0131] The first core 3f and the second core 3s are formed from molded bodies of different materials. Different materials refer to different relative magnetic permeabilities. Examples of molded bodies include powder-pressed bodies and composite material molded bodies. For example, even if the first core 3f and the second core 3s are formed from powder-pressed bodies, if the material and content of the soft magnetic powder constituting the powder-pressed bodies are different, they are considered to be made from different materials. Similarly, even if the first core 3f and the second core 3s are formed from composite material molded bodies, if at least one of the soft magnetic powder and resin constituting the composite material is different, or even if the soft magnetic powder and resin are the same material, but the contents of the soft magnetic powder and resin are different, they are also considered to be made from different materials. Furthermore, these chips can also be formed from laminates.

[0132] Powder compacted bodies are constructed by compressing soft magnetic powder. Compared to composite materials, powder compacted bodies allow for a higher proportion of soft magnetic powder in the chip. Therefore, powder compacted bodies readily improve magnetic properties. Examples of magnetic properties include relative permeability and saturation flux density. Furthermore, compared to composite material bodies, powder compacted bodies contain less resin and more soft magnetic powder, resulting in excellent heat dissipation. The content of magnetic powder in the powder compacted body can be, for example, between 85% by volume and 99.99% by volume. This content is for a powder compacted body of 100% by volume.

[0133] The composite material is formed by dispersing soft magnetic powder in a resin. It is obtained by filling a mold with a flowable raw material containing soft magnetic powder dispersed in uncured resin and then curing the resin. The content of soft magnetic powder in the resin can be easily adjusted in the composite material. Therefore, the magnetic properties of the composite material can be easily adjusted. Based on this, compared with powder-molded articles, even complex shapes can be easily formed in the composite material. The content of soft magnetic powder in the molded composite material can be, for example, 20% by volume or more and 80% by volume or less. The resin content in the molded composite material can be, for example, 20% by volume or more and 80% by volume or less. These contents are values ​​when the composite material is 100% by volume.

[0134] A laminate is constructed by stacking multiple thin magnetic sheets. The thin magnetic sheets have an insulating coating. Examples of thin magnetic sheets include electromagnetic steel sheets.

[0135] Particles constituting soft magnetic powder can include soft magnetic metal particles, coated particles with an insulating coating around their outer periphery, and soft magnetic non-metal particles. Examples of soft magnetic metals include pure iron and iron-based alloys. Examples of iron-based alloys include Fe-Si alloys and Fe-Ni alloys. Examples of insulating coatings include phosphates. Examples of soft magnetic non-metals include ferrites.

[0136] The resins used in composite materials can be, for example, thermosetting resins and thermoplastic resins. Examples of thermosetting resins include epoxy resins, phenolic resins, silicone resins, and urethane resins. Examples of thermoplastic resins include polyphenylene sulfide resins, polyamide resins, liquid crystal polymers, polyimide resins, and fluoropolymers. Examples of polyamide resins include nylon 6, nylon 66, and nylon 9T.

[0137] These resins may also contain ceramic fillers. Examples of ceramic fillers include alumina and silica. Resins containing these ceramic fillers exhibit excellent heat dissipation and electrical insulation properties.

[0138] The content of soft magnetic powder in the pressed powder molded body or the molded body of the composite material is considered equivalent to the area ratio of soft magnetic powder in the cross-section of the molded body. The content of soft magnetic powder in the molded body is calculated as follows. The cross-section of the molded body is observed using a SEM (scanning electron microscope) to obtain images. The SEM magnification is set to 200x or higher and 500x or lower. At least 10 images are obtained. The total cross-sectional area is set to 0.1 cm². 2 The above describes a method for obtaining one or multiple observation images of a single cross-section. Image processing is then performed on each image to extract the particle outlines. Image processing methods include, for example, binarization. The area ratio of soft magnetic particles in each image is calculated, and the average value of this area ratio is determined. This average value is then considered as the content of the soft magnetic powder.

[0139] In this configuration, the first core 3f is formed from a molded composite material, and the second core 3s is formed from a pressed powder molded body. Because the first core 3f is formed from a molded composite material and the second core 3s is formed from a pressed powder molded body, there is no long gap 3g of length Lg between the first core 3f and the second core 3s, making it easy to adjust the inductance and heat dissipation. Furthermore, the reactor 1 is formed from a pressed powder molded body with relatively high thermal conductivity in the second core 3s, thereby easily improving heat dissipation.

[0140] (Gap)

[0141] The gap 3g can be an air gap as in this method, or it can be different from this method and be made of a component made of a material with a relative permeability that is smaller than that of the first core 3f and the second core 3s.

[0142] The gap portion 3g is disposed at least on either the exterior or interior of the winding portion 21. Specifically, in the magnetic core 3 of this embodiment, the gap portion 3g can be disposed at least at one of the following locations: between the first side chip 321f and the first side chip 321s; between the second side chip 322f and the second side chip 322s; and between the first intermediate chip 31f and the second intermediate chip 31s. Preferably, the gap portion 3g is disposed inside the winding portion 21, as in this embodiment. That is, the gap portion 3g is preferably disposed between the first intermediate chip 31f and the second intermediate chip 31s. By disposing the gap portion 3g inside the winding portion 21, compared to disposing it outside the winding portion 21, it is easier to reduce eddy current losses generated in the winding portion 21 due to leakage flux intrusion.

[0143] The length Lg of the gap portion 3g along the first direction D1 is preferably 2 mm or less, for example. In the case of multiple gap portions 3g, the aforementioned length Lg refers to the length of one gap portion 3g. That is, when the length Lg of each individual gap portion 3g is 2 mm or less, the sum of the aforementioned length Lg of the multiple gap portions 3g can exceed 2 mm. In particular, the length Lg of the gap portion 3g disposed inside the winding portion 21 along the first direction D1 is preferably 2 mm or less. When the aforementioned length Lg is 2 mm or less, leakage flux is low, and the effect of reducing eddy current losses is easily increased. The aforementioned length Lg is further preferably 1.5 mm or less, and particularly preferably 1.0 mm or less. The aforementioned length Lg can be, for example, 0.1 mm or more. The aforementioned length Lg is further preferably 0.3 mm or more. When the aforementioned length Lg is 0.1 mm or more, further 0.3 mm, and particularly 0.5 mm or more, the predetermined inductance is easily ensured.

[0144] [other]

[0145] Although the reactor 1 is not shown in the figure, it may include at least one housing, adhesive layer, retaining member, and molding resin part. The housing internally houses the assembly of coil 2 and magnetic core 3. The assembly inside the housing may also be embedded by a sealing resin part. The adhesive layer fixes the assembly to a mounting surface, fixes the assembly to the inner bottom surface of the housing, and fixes the housing to the mounting surface, etc. The retaining member is provided between coil 2 and magnetic core 3 to ensure insulation between coil 2 and magnetic core 3. The molding resin part covers the outer periphery of the assembly and is provided between coil 2 and magnetic core 3, making coil 2 and magnetic core 3 integrated.

[0146] [Effects]

[0147] The reactor 1 of this embodiment allows for inductance adjustment without increasing the length Lg of the gap 3g between the first core 3f and the second core 3s. Furthermore, the reactor 1 of this embodiment is easy to adjust and its heat dissipation is easily improved. This is because the magnetic core 3 of the reactor 1 of this embodiment is a combination of the first core 3f, which is formed from a molded composite material, and the second core 3s, which is formed from a pressed powder molded material. In addition, the reactor 1 of this embodiment can be appropriately used in reactors cooled by cooling components with uneven cooling performance. The second core 3s, with high thermal conductivity, is positioned on the side of the cooling component with low cooling performance, while the first core 3f, with low thermal conductivity, is positioned on the side of the cooling component with high cooling performance. As a result, the first core 3f and the second core 3s are cooled uniformly, and the maximum temperature of the magnetic core 3 is reduced. Thus, because the maximum temperature of the magnetic core 3 is reduced, the reactor 1 has low losses. Furthermore, the reactor 1 is less prone to large-scale manufacturing. This is because: As mentioned above, reactor 1 is easy to adjust and its heat dissipation is easy to improve, so it is not necessary to install a cooling pipe like the existing reactors described above.

[0148] Implementation Method 2

[0149] [Reactor]

[0150] Reference Figure 4 The reactor 1 of Embodiment 2 will be described. The reactor 1 of this embodiment differs from the reactor 1 of Embodiment 1 in that the combination of the first core 3f and the second core 3s is of type EI. The following description focuses on the differences from Embodiment 1. Descriptions of structures identical to those in Embodiment 1 are omitted. These aspects are also the same in Embodiments 3 and 4, which will be described later.

[0151] [Magnetic Core]

[0152] The magnetic core 3 has the same first end chip 33f and second end chip 33s as in Embodiment 1, and a middle core 31, a first side core 321, and a second side core 322, which are different from Embodiment 1. The length L1f of the middle core 31 along the first direction D1 is shorter than that of the first side core 321 along the first direction D1, L21f, and the second side core 322 along the first direction D1, L22f, as in Embodiment 1. The middle core 31 is composed of a first middle chip 31f. The first side core 321 is composed of a first side chip 321f. The second side core 322 is composed of a second side chip 322f. The first core 3f and the second core 33s are asymmetrical, as in Embodiment 1.

[0153] (First Core)

[0154] The first core 3f is E-shaped. The first core 3f is a molded body formed by integrating the first end chip 33f, the first intermediate chip 31f, the first side chip 321f, and the second side chip 322f. The length L21f of the first side chip 321f along the first direction D1 and the length L22f of the second side chip 322f along the first direction D1 are the same and longer than the length L1f of the first intermediate chip 31f along the first direction D1. The lengths L21f and L22f in this embodiment are longer than those in Embodiment 1, and longer than the axial length of the winding portion 21. Like in Embodiment 1, the first core 3f is also formed from a molded body of composite material.

[0155] (Second Core)

[0156] The second core 3s is I-shaped. The second core 3s is composed of a second end chip 33s. Like in Embodiment 1, the second core 3s is composed of a powder-molded body.

[0157] The first core 3f and the second core 3s are combined such that the end faces of the first side chip 321f and the second side chip 322f of the first core 3f are in contact with the end face of the second end chip 33s of the second core 3s. When combined in this way, because the above-mentioned length relationship is satisfied, a gap is provided between the end face of the first intermediate chip 31f of the first core 3f and the end face of the second end chip 33s.

[0158] The relative magnetic permeability, iron loss, and thermal conductivity of the first core 3f and the second core 3s are the same as in Embodiment 1.

[0159] (Gap)

[0160] The gap portion 3g is the same as in Embodiment 1, consisting of an air gap. However, the location of the gap portion 3g differs from that in Embodiment 1; it is situated between the end face of the first intermediate chip 31f and the end face of the second end chip 33s, and outside the winding portion 21. The length Lg of the gap portion 3g along the first direction D1 is the same as in Embodiment 1, being 2 mm or less.

[0161] [Effects]

[0162] The reactor 1 of this embodiment, like the reactor 1 of Embodiment 1, does not require large-scale manufacturing and is easy to adjust inductance and heat dissipation. Because the gap portion 3g of this reactor 1 is located outside the winding portion 21, compared to the reactor 1 of Embodiment 1, although the reduction in eddy current losses due to the reduction in leakage flux is less effective, it is easier to combine the first core 3f and the second core 3s. This is because the second core 3s does not have a chip with an end face facing the first intermediate chip 31f within the winding portion 21. Furthermore, compared to the reactor 1 of Embodiment 1, the density distribution of the second core 3s is less likely to occur in this reactor 1. Because the second core 3s is composed only of the second end chip 33s, the pressure during the forming of the second core 3s is less prone to deviation.

[0163] Implementation Method 3

[0164] [Reactor]

[0165] Reference Figure 5 The reactor 1 of Embodiment 3 is described below. The reactor 1 of this embodiment differs from the reactor 1 of Embodiment 1 in that the combination of the first core 3f and the second core 3s is of the ET type.

[0166] [Magnetic Core]

[0167] The magnetic core 3 has the same first end chip 33f, second end chip 33s, and intermediate core 31 as in Embodiment 1, and a first side core 321 and a second side core 322, which differ from Embodiment 1. The length (L1f + L1s) of the intermediate core 31 along the first direction D1 is shorter than that of the first side core 321 along the first direction D1 (L21f) and the second side core 322 along the first direction D1 (L22f), as in Embodiment 1. The first side core 321 is composed of a single first side chip 321f. The second side core 322 is composed of a single second side chip 322f. The first core 3f and the second core 3s are asymmetrical, as in Embodiment 1.

[0168] (First Core)

[0169] The first core 3f is E-shaped. The first core 3f is a molded body integrally formed of a first end chip 33f, a first intermediate chip 31f, a first side chip 321f, and a second side chip 322f. The length L21f of the first side chip 321f along the first direction D1 and the length L22f of the second side chip 322f along the first direction D1 are the same, and longer than the length L1f of the first intermediate chip 31f along the first direction D1. The lengths L21f and L22f in this embodiment are longer than those in Embodiment 1, and also longer than the axial length of the winding portion 21. Furthermore, the length L1f can be different from the length L1s of the second intermediate chip 31s along the first direction D1 (described later), as in this embodiment, or it can be different from this embodiment and the same as the length L1s. The length L1f in this embodiment is the same as the L1f in Embodiment 1, and longer than the length L1s in this embodiment. The first core 3f, like in Embodiment 1, is composed of a molded body of composite material.

[0170] (Second Core)

[0171] The second core 3s has a T-shaped shape. The second core 3s is a molded body formed by integrating the second end chip 33s and the second intermediate chip 31s. The length L1s in this embodiment is the same as the length L1s in Embodiment 1, and shorter than the length L1f in this embodiment. The length L1s, like in Embodiment 1, is less than twice the length L3s. The second core 3s, like in Embodiment 1, is constructed from a powder-pressed molded body.

[0172] The first core 3f and the second core 3s are combined such that the end faces of the first side chip 321f and the second side chip 322f of the first core 3f are in contact with the end face of the second end chip 33s of the second core 3s. When combined in this way, because the above-mentioned length relationship is satisfied, a gap is provided between the end face of the first intermediate chip 31f of the first core 3f and the end face of the second intermediate chip 31s of the second core 3s.

[0173] The relative magnetic permeability, iron loss, and thermal conductivity of the first core 3f and the second core 3s are the same as in Embodiment 1.

[0174] (Gap)

[0175] The gap portion 3g, like in Embodiment 1, is composed of an air gap. The location of the gap portion 3g, also like in Embodiment 1, is inside the winding portion 21, between the end face of the first intermediate chip 31f and the end face of the second intermediate chip 31s. The length Lg of the gap portion 3g along the first direction D1, like in Embodiment 1, is 2 mm or less.

[0176] [Effects]

[0177] The reactor 1 in this method is the same as the reactor 1 in Embodiment 1, and it will not be large in size, making it easy to adjust the inductance and heat dissipation.

[0178] Implementation Method 4

[0179] [Reactor]

[0180] Reference Figure 6 The reactor 1 of Embodiment 4 is described below. The reactor 1 of this embodiment differs from the reactor 1 of Embodiment 1 in that the combination of the first core 3f and the second core 3s is of the EU type.

[0181] [Magnetic Core]

[0182] The magnetic core 3 has the same first end chip 33f, second end chip 33s, first side core 321, and second side core 322 as in Embodiment 1, and an intermediate core 31 different from that in Embodiment 1. The length L1f of the intermediate core 31 along the first direction D1 is the same as in Embodiment 1, shorter than the length (L21f+L21s) of the first side core 321 along the first direction D1 and the length (L22f+L22s) of the second side core 322 along the first direction D1. The intermediate core 31 is composed of a first intermediate chip 31f. The first core 3f and the second core 3s are asymmetrical, as in Embodiment 1.

[0183] (First Core)

[0184] The first core 3f is E-shaped. The first core 3f is a molded body formed by integrating the first end chip 33f, the first intermediate chip 31f, the first side chip 321f, and the second side chip 322f.

[0185] The length L21f of the first side chip 321f along the first direction D1 is the same as the length L22f of the second side chip 322f along the first direction D1. The length L1f of the first intermediate chip 31f along the first direction D1 is longer than both L21f and L22f.

[0186] The lengths L21f and L22f described above may differ from the lengths L21s of the first side chip 321s and L22s of the second side chip 322s along the first direction D1 of the second core 3s described later, as in this embodiment, and may also differ from this embodiment and be the same as the lengths L21s and L22s described above. The lengths L21f and L22f described above in this embodiment are the same as the lengths L21f and L22f described in Embodiment 1, and are longer than the lengths L21s and L22s described above in this embodiment. L1f is longer than the L1f described in Embodiment 1 and is equal to the length in the axial direction of the winding portion 21. The first core 3f, like in Embodiment 1, is constructed from a molded body of composite material.

[0187] (Second Core)

[0188] The second core 3s has a U-shaped shape. The second core 3s is a molded body formed by integrating the second end chip 33s, the first side chip 321s, and the second side chip 322s. The lengths L21s and L22s of this embodiment are as described above, the same as those in Embodiment 1, and shorter than those in this embodiment. The lengths L21s and L22s, like in Embodiment 1, are less than twice the length L3s. The second core 3s, like in Embodiment 1, is constructed from a powder-pressed molded body.

[0189] The first core 3f and the second core 3s are combined such that the end faces of the first side chip 321f and the second side chip 322f of the first core 3f are each in contact with the end faces of the first side chip 321s and the second side chip 322s of the second core 3s. When combined in this way, because the above-mentioned length relationship is satisfied, a gap is provided between the end face of the first intermediate chip 31f of the first core 3f and the end face of the second end chip 33s of the second core 3s.

[0190] The relative magnetic permeability, iron loss, and thermal conductivity of the first core 3f and the second core 3s are the same as in Embodiment 1.

[0191] The gap portion 3g is the same as in Embodiment 1, consisting of an air gap. However, the location of the gap portion 3g differs from that in Embodiment 1; it is situated between the end face of the first intermediate chip 31f and the end face of the second end chip 33s, and outside the winding portion 21. The length Lg of the gap portion 3g along the first direction D1 is the same as in Embodiment 1, being 2 mm or less.

[0192] [Effects]

[0193] The reactor 1 of this embodiment, like the reactor 1 of Embodiment 1, does not require large-scale operation and is easy to adjust inductance and heat dissipation. Because the gap portion 3g of the reactor 1 of this embodiment is located outside the winding portion 21, compared to the reactor 1 of Embodiment 1, although the reduction in eddy current losses due to the reduction in leakage flux is less effective, it is easier to combine the first core 3f and the second core 3s. This is because the second core 3s does not have a chip with an end face facing the first intermediate chip 31f within the winding portion 21.

[0194] <Implementation Method 5>

[0195] Converters and Power Conversion Devices

[0196] The reactor 1 of Embodiments 1 to 4 can be used for applications that satisfy the following energizing conditions. Examples of energizing conditions include a maximum DC current of 100A or more and 1000A or less, an average voltage of 100V or more and 1000V or less, and an operating frequency of 5kHz or more and 100kHz or less. The reactor 1 of Embodiments 1 to 4 can be representatively used as a component of a converter in vehicles such as electric vehicles and hybrid vehicles, or as a component of a power conversion device equipped with such a converter.

[0197] 1200 vehicles including hybrid vehicles and electric vehicles Figure 7 The vehicle shown includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and an electric motor 1220 driven by power supplied from the main battery 1210 for driving. The electric motor 1220 is typically a three-phase AC motor, which drives the wheels 1250 during driving and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 also includes an engine 1300 in addition to the electric motor 1220. Figure 7 In the middle, a socket is shown as the charging part of vehicle 1200, but it can be set to have a plug.

[0198] The power conversion device 1100 includes a converter 1110 connected to the main battery 1210 and an inverter 1120 connected to the converter 1110 and performing DC-AC conversion. In this example, the converter 1110 boosts the input voltage of the main battery 1210 (between 200V and 300V) to between 400V and 700V to supply power to the inverter 1120 when the vehicle 120 is in motion. During regeneration, the converter 1110 steps down the input voltage from the motor 1220 via the inverter 1120 to a DC voltage suitable for the main battery 1210, charging the main battery 1210. The input voltage is a DC voltage. The inverter 1120 converts the DC boosted by the converter 1110 to a predetermined AC voltage to supply power to the motor 1220 when the vehicle 1200 is in motion, and during regeneration, converts the AC output from the motor 1220 to DC for output to the converter 1110.

[0199] Converter 1110 Figure 8 The diagram shows a combination of multiple switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115. The input voltage is transformed through repeated switching on and off. This input voltage transformation refers to step-up and step-down voltage conversion. The switching elements 1111 utilize power devices such as field-effect transistors (FETs) and insulated-gate bipolar transistors (IGBTs). The reactor 1115 functions by utilizing the coil properties that impede changes in the current flowing through the circuit, thus smoothing the change in current due to switching operations. The reactor 1115 is one of any of the reactors described in Embodiments 1 to 4. By incorporating a reactor 1 that does not require large dimensions and has excellent heat dissipation, the power conversion device 1100 and the converter 1110 can also be expected to be miniaturized and have improved heat dissipation.

[0200] In addition to converter 1110, vehicle 1200 also includes a power supply converter 1150 connected to the main battery 1210, and an auxiliary power supply converter 1160 connected to the auxiliary battery 1230 (which serves as the power source for auxiliary equipment 1240) and the main battery 1210, which converts the high voltage of the main battery 1210 to a low voltage. Converter 1110 typically performs DC-DC conversion, but power supply converter 1150 and auxiliary power supply converter 1160 perform AC-DC conversion. Power supply converter 1150 also includes a DC-DC converter. The reactors of power supply converter 1150 and auxiliary power supply converter 1160 have the same structure as the reactor 1 in any of embodiments 1 to 4, and reactors with appropriately modified sizes and shapes can be used. Furthermore, converters that convert input power, converters that only boost voltage, or converters that only buck voltage can also utilize the reactor 1 in any of embodiments 1 to 4.

[0201] The invention is not limited to these examples, but as indicated by the claims, it is intended to include all modifications that are equivalent in meaning and scope to the claims.

[0202] Explanation of reference numerals in the attached figures

[0203] 1 reactor

[0204] 2 coils

[0205] 21 winding section, 21a one end, 21b the other end

[0206] 3 magnetic core, 3f first core, 3s second core

[0207] 31 Intermediate Core

[0208] 31f first intermediate chip, 31s second intermediate chip

[0209] 321 First side core

[0210] 321f first-side chip, 321s first-side chip

[0211] 322 Second Side Core

[0212] 322f second-side chip, 322s second-side chip

[0213] 33f first-side chip, 33s second-side chip

[0214] 3g gap

[0215] D1 First Direction, D2 Second Direction, D3 Third Direction

[0216] Lengths of L1f, L1s, L21f, L21s, L22f, L22s, L3f, L3s, and Lg

[0217] 1100 power conversion device, 1110 converter

[0218] 1111 Switching element, 1112 Drive circuit, 1115 Reactor

[0219] 1120 inverter

[0220] Converters for 1150 power supply units and 1160 auxiliary power supplies

[0221] 1200 vehicles

[0222] 1210 main battery, 1220 electric motor, 1230 auxiliary battery

[0223] 1240 auxiliary machinery, 1250 wheels

[0224] 1300 engine

Claims

1. A reactor comprising a coil and a magnetic core, The coil has a winding portion. The number of the winding portions is one. The winding section is rectangular cylindrical in shape. The outer peripheral surface of the winding portion includes a portion that contacts the object on which the reactor is installed. The magnetic core is a composition formed by combining a first core and a second core. The first core and the second core are formed from molded bodies made of different materials. The first core is constructed from a composite material in which soft magnetic metal powder is dispersed in resin. The second core is constructed from a powder-pressed body containing soft magnetic metal powder. The soft magnetic metal constituting the soft magnetic metal powder includes at least one of pure iron and iron-based alloys. The content of the soft magnetic metal powder in the molded body of the composite material is more than 20% by volume.

2. A reactor comprising a coil and a magnetic core, The coil has a winding portion. The number of the winding portions is one. The winding section is rectangular cylindrical in shape. The magnetic core is a composition formed by combining a first core and a second core, and further comprises: The first end chip and the second end chip face each end face of the winding portion; The intermediate core has a portion disposed inside the winding portion; and The first side core and the second side core are arranged on the outer periphery of the winding portion, with the middle core spaced apart. The first core and the second core are combined in the axial direction of the winding portion. The first core is a molded body made of a composite material in which soft magnetic metal powder is dispersed in resin. It has an E-shaped form having a first end chip, a portion of the middle core, a first side core, and a second side core. The second core is constructed from a powder-pressed body containing soft magnetic metal powder, and has a T-shaped form with the second end chip and the remaining portion of the middle core. The lengths (L21f) of the first side core and the second side core are the same, and both are longer than the length (L1f) of a portion of the middle core. The length (L1s) of the remaining portion of the intermediate core is shorter than the length (L1f) of a portion of the intermediate core, and is less than twice the length (L3s) of the second end chip. The soft magnetic metal constituting the soft magnetic metal powder includes at least one of pure iron and iron-based alloys. The content of the soft magnetic metal powder in the molded body of the composite material is more than 20% by volume.

3. A reactor comprising a coil and a magnetic core, The coil has a winding portion. The number of the winding portions is one. The winding section is rectangular cylindrical in shape. The outer peripheral surface of the winding portion includes a portion that contacts the object on which the reactor is installed. The magnetic core is a composition formed by combining a first core and a second core, and further comprises: The first end chip and the second end chip face each end face of the winding portion; The intermediate core has a portion disposed inside the winding portion; and The first side core and the second side core are arranged on the outer periphery of the winding portion, with the middle core spaced apart. The first core and the second core are combined in the axial direction of the winding portion. The first core is a molded body made of a composite material in which soft magnetic metal powder is dispersed in resin. It has an E-shaped form having a first end chip, a portion of the middle core, a first side core, and a second side core. The second core is constructed from a powder-pressed body containing soft magnetic metal powder, and has a T-shaped form with the second end chip and the remaining portion of the middle core. The lengths (L21f) of the first side core and the second side core are the same, and both are longer than the length (L1f) of a portion of the middle core. The length (L1s) of the remaining portion of the intermediate core is shorter than the length (L1f) of a portion of the intermediate core, and is less than twice the length (L3s) of the second end chip. The soft magnetic metal constituting the soft magnetic metal powder includes at least one of pure iron and iron-based alloys. The content of the soft magnetic metal powder in the molded body of the composite material is more than 20% by volume.

4. The reactor according to claim 1, wherein, The magnetic core has: The first end chip and the second end chip face each end face of the winding portion; The intermediate core has a portion disposed inside the winding portion; and The first side core and the second side core are arranged on the outer periphery of the winding portion, with the middle core spaced apart. The first core and the second core are combined in the axial direction of the winding portion, and the first core has: The first chip; and At least one of the group consisting of at least a portion of the intermediate core, at least a portion of the first side core, and at least a portion of the second side core, wherein the second core has at least a second end chip selected from the group consisting of a second end chip, the remainder of the intermediate core, the remainder of the first side core, and the remainder of the second side core.

5. The reactor according to claim 4, wherein, The second core portion has at least one portion selected from the group consisting of the remaining portion of the intermediate core portion, the remaining portion of the first side core portion, and the remaining portion of the second side core portion. The lengths (L1) of the remaining portion of the middle core, (L21) of the remaining portion of the first side core, and (L22) of the remaining portion of the second side core are less than twice the length (L3) of the second end chip.

6. The reactor according to claim 4, wherein, The second core portion has at least one portion selected from the group consisting of the remaining portion of the intermediate core portion, the remaining portion of the first side core portion, and the remaining portion of the second side core portion. The lengths (L1) of the remaining portion of the middle core, (L21) of the remaining portion of the first side core, and (L22) of the remaining portion of the second side core exceed twice the length (L3) of the second end chip.

7. The reactor according to any one of claims 4 to 6, wherein, The shapes of the first core and the second core are asymmetrical.

8. The reactor according to any one of claims 2 to 6, wherein, The magnetic core has a gap portion disposed between the first core portion and the second core portion. The gap portion is disposed inside the winding portion.

9. The reactor according to claim 8, wherein, The length of the gap portion along the axial direction of the winding portion is less than 2 mm.

10. The reactor according to any one of claims 1 to 6, wherein, The relative permeability of the first core is less than that of the second core.

11. The reactor according to claim 10, wherein, The relative permeability of the first core is less than 50. The relative permeability of the second core is 50 or higher.

12. The reactor according to any one of claims 1 to 6, wherein, The iron loss of the second core is greater than that of the first core. The thermal conductivity of the second core is greater than that of the first core.

13. A converter comprising the reactor according to any one of claims 1 to 12.

14. A power conversion device comprising the converter of claim 13.

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