Reactor, converter, and power conversion device

Abstract

To provide a reactor in which inductance and heat dissipation can be adjusted easily without increasing the size.SOLUTION: A coil having one winding portion and a magnetic core, an outer circumferential surface of the winding portion including a portion that comes into contact with an installation target of the reactor, the magnetic core including an E-shaped first core portion, a T-shaped second core portion, and a gap portion, wherein the first core portion is constituted by a molded body of a composite material, the second core portion is constituted by a powder molded body, the gap portion is disposed between the first middle core portion of the first core portion and the second middle core portion of the second core portion inside the winding portion, a length from the second end surface of the winding portion to the gap portion is 0.2 times or more and 0.49 times or less a length of the winding portion, and a total volume of a volume of the first core portion, a volume of the second core portion, and a volume of the gap portion is 50cm3 or more and 500cm3 or less.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] The reactor of Patent Document 1 includes a coil, a magnetic core, a case, and a cooling pipe. The coil is formed by spirally winding a wire. There is one coil, and the coil is cylindrical. The magnetic core has an inner core portion and an outer core portion. The inner core portion is disposed inside the coil. The outer core portion covers both end surfaces of the inner core portion and both end surfaces and the outer peripheral surface of the coil. The inner core portion and the outer core portion are composed of different materials. Specifically, the inner core portion is composed of a powder compact, and the outer core portion is composed of a composite material compact. The case houses the assembly of the coil and the magnetic core. The assembly is housed in the case by disposing the coil and the inner core portion inside the case, filling the case with raw materials for the composite material, and allowing it to harden. A refrigerant flows through the cooling pipe. The cooling pipe is spirally wound around the circumferential direction of the case so as to contact the outer peripheral surface of the case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-74062 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned assembly has an inner core portion and an outer core portion made of different materials, making it easy to adjust the inductance. On the other hand, the above-mentioned assembly has a coil and an inner core portion embedded in the outer core portion, making it difficult to adjust the heat dissipation. This is because the surface of the above-mentioned assembly is essentially made of only the constituent material of the outer core portion. Furthermore, the above-mentioned assembly has low heat dissipation. This is because the outer core portion is made of a composite material and has a relatively low thermal conductivity. Therefore, the above-mentioned reactor improves the heat dissipation performance of the assembly by housing the above-mentioned assembly in a case around which a cooling pipe is wound. However, the reactor becomes large because the cooling pipe is wound around the case.

[0005] An object of the present disclosure is to provide a reactor that allows easy adjustment of inductance and heat dissipation without increasing the size. Another object of the present disclosure is to provide a converter including the reactor. Still another object of the present disclosure is to provide a power conversion device including the converter. [Means for solving the problem]

[0006] The reactor of the present disclosure includes: A reactor including a coil and a magnetic core, the coil has a winding portion; the number of the winding portions is one, an outer circumferential surface of the winding portion includes a portion that comes into contact with an object on which the reactor is to be installed, The magnetic core is an E-shaped first core portion and a T-shaped second core portion combined in the axial direction of the winding portion; a gap portion provided between the first core portion and the second core portion, the first core portion is composed of a molded body of a composite material, which is an integral body including a first end core portion facing a first end face of the winding portion, a first middle core portion having a portion disposed inside the winding portion, and a first side core portion and a second side core portion disposed on the outer periphery of the winding portion so as to sandwich the first middle core portion, the second core portion is composed of a powder-compressed compact integrally formed with a second end core portion facing the second end surface of the winding portion and a second middle core portion having a portion disposed inside the winding portion, a length of the second middle core portion along the axial direction of the winding portion is shorter than a length of the first middle core portion along the axial direction of the winding portion, the gap portion is disposed inside the winding portion between the first middle core portion and the second middle core portion, a length from the second end surface to the gap portion is 0.2 times or more and 0.49 times or less the length of the winding portion, The total volume Va of the first core portion, the second core portion, and the gap portion is 50 cm 3 More than 500cm 3 The following is the result.

[0007] The converter of the present disclosure includes the reactor of the present disclosure.

[0008] The power conversion device of the present disclosure includes the converter of the present disclosure. [Effects of the Invention]

[0009] The reactor of the present disclosure allows easy adjustment of inductance and heat dissipation without increasing the size.

[0010] The converter and the power conversion device of the present disclosure have excellent heat dissipation properties without increasing in size. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view showing the entire reactor of the first embodiment. [Figure 2] FIG. 2 is a schematic side view showing the entire reactor of the first embodiment. [Figure 3] FIG. 3 is a schematic perspective view showing an exploded state of the reactor of the first embodiment. [Figure 4] FIG. 4 is a schematic top view showing the entire reactor of the first embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the power supply system of a hybrid vehicle. [Figure 6] FIG. 6 is a circuit diagram showing an example of a power conversion device including a converter. DETAILED DESCRIPTION OF THE INVENTION

[0012] <<Description of Embodiments of the Present Disclosure>> First, embodiments of the present disclosure will be listed and described.

[0013] (1) A reactor according to one embodiment of the present disclosure includes: A reactor including a coil and a magnetic core, the coil has a winding portion; the number of the winding portions is one, an outer circumferential surface of the winding portion includes a portion that comes into contact with an object on which the reactor is to be installed, The magnetic core is an E-shaped first core portion and a T-shaped second core portion combined in the axial direction of the winding portion; a gap portion provided between the first core portion and the second core portion, the first core portion is composed of a molded body of a composite material, which is an integral body including a first end core portion facing a first end face of the winding portion, a first middle core portion having a portion disposed inside the winding portion, and a first side core portion and a second side core portion disposed on the outer periphery of the winding portion so as to sandwich the first middle core portion, the second core portion is composed of a powder-compressed compact integrally formed with a second end core portion facing the second end surface of the winding portion and a second middle core portion having a portion disposed inside the winding portion, a length of the second middle core portion along the axial direction of the winding portion is shorter than a length of the first middle core portion along the axial direction of the winding portion, the gap portion is disposed inside the winding portion between the first middle core portion and the second middle core portion, a length from the second end surface to the gap portion is 0.2 times or more and 0.49 times or less the length of the winding portion, The total volume Va of the first core portion, the second core portion, and the gap portion is 50 cm 3 More than 500cm 3 The following is the result.

[0014] The inductance of the reactor is easy to adjust. In particular, the inductance of the reactor is easy to adjust without a large gap between the first and second core portions because the magnetic core is not made of a single material but is made of a first core portion made of a composite material compact and a second core portion made of a powder compact.

[0015] The heat dissipation performance of the above reactor is easier to adjust than that of the conventional reactor described above. The magnetic core of the conventional reactor is formed by embedding a core part with a relatively high thermal conductivity in a core part with a relatively low thermal conductivity. In other words, the surface of the magnetic core of the conventional reactor is essentially made of a single material. In contrast, the magnetic core of the above reactor is formed by combining a first core part and a second core part in the axial direction of the winding part, so the surface of the magnetic core is made of different materials.

[0016] The above reactor has an improved heat dissipation property. This is because the winding portion of the above reactor includes a portion that contacts the installation object, and thus the heat of the coil can be effectively dissipated through the installation object. In particular, the above reactor has an improved heat dissipation property compared to the above-mentioned conventional reactor. In the above-mentioned conventional reactor, the surface of the magnetic core is composed only of the core portion having a relatively low thermal conductivity, as described above. In contrast, the above reactor has a magnetic core surface that can include a surface composed of a powder compact having a relatively high thermal conductivity.

[0017] The reactor described above can be suitably used as a reactor cooled by a cooling member with uneven cooling performance. Of the first and second core portions, the second core portion with higher thermal conductivity is arranged on the side of the cooling member with lower cooling performance, and the first core portion with lower thermal conductivity is arranged on the side of the cooling member with higher cooling performance. This allows the first and second core portions to be cooled evenly, reducing the maximum temperature of the magnetic core.

[0018] The reactor is difficult to increase in size because, as described above, the heat dissipation performance of the reactor can be easily adjusted and increased, and therefore, unlike the conventional reactor described above, a cooling pipe need not be provided.

[0019] The reactor has only one winding section, so the installation area in the direction perpendicular to the axial direction can be made smaller than when multiple winding sections are arranged in parallel in a direction perpendicular to the axial direction of the winding section.

[0020] The reactor is easy to manufacture because it can be manufactured by simply assembling the prefabricated first and second core portions to the coil.

[0021] The reactor has low loss. This is because the length of the second middle core portion is shorter than the length of the first middle core portion, thereby reducing the proportion of powder compacts, which have higher loss than the composite material compact. Furthermore, the reactor has a gap portion disposed inside the winding portion, and the length from the second end face to the gap portion is 0.2 times or more the length of the winding portion, making it difficult for leakage magnetic flux to penetrate the winding portion. This makes it easy to reduce eddy current loss generated in the winding portion. Furthermore, the length from the second end face to the gap portion is 0.49 times or less the length of the winding portion, making it possible to increase the proportion of composite material compacts, which have lower loss than the powder compact, inside the winding portion. And, as described above, the reactor can reduce the maximum temperature of the magnetic core.

[0022] The reactor can suppress problems such as the influence of leakage magnetic flux on peripheral devices, because the gap portion of the reactor is disposed inside the winding portion and the length from the second end face to the gap portion is 0.2 times or more the length of the winding portion, which makes it easy to suppress leakage of magnetic flux to the outside of the winding portion.

[0023] A second core portion having a T-shape is easier to manufacture than an E-shape. Therefore, a second core portion having a T-shape is easier to manufacture with precision than an E-shape. Therefore, when a second core portion having a T-shape is combined with a first core portion, an unnecessary gap is less likely to be formed than when the second core portion has an E-shape.

[0024] The total volume of the reactor is 50 cm 3 More than 500cm 3 The following characteristics make the converter suitable for use in an electric vehicle, a hybrid vehicle, or a fuel cell vehicle.

[0025] Generally, the larger the volume of the reactor, the easier it is to generate heat and the harder it is to dissipate heat. However, since the reactor can easily increase its heat dissipation as described above, when the total volume Va is 50 cm 3 Even if the temperature is above this, heat generation can be easily suppressed.

[0026] (2) As one form of the above reactor, The ratio of the volume of the second core portion to the total volume Va is preferably 25% or more and 40% or less.

[0027] If the ratio is 25% or more, the heat dissipation performance of the reactor is likely to be high, and if the ratio is 40% or less, the loss of the reactor is likely to be reduced.

[0028] (3) As one form of the above reactor, The ratio of the volume of the second middle core portion to the total volume of the first middle core portion, the second middle core portion, and the gap portion may be 15% or more and 49% or less.

[0029] If the ratio is 15% or more, the heat dissipation performance of the reactor is likely to be high, and if the ratio is 49% or less, the loss of the reactor is likely to be reduced.

[0030] (4) As one form of the above reactor, The ratio of the thickness of the gap portion to the total length of the length of the first middle core portion, the length of the second middle core portion, and the thickness of the gap portion may be 0.001 or more and 0.1 or less.

[0031] If the ratio is 0.001 or more, it is easy to ensure a predetermined inductance. If the ratio is 0.1 or less, leakage flux is small, and the effect of reducing eddy current loss is likely to be high.

[0032] (5) As one form of the above reactor, The thickness of the gap portion is preferably 0.1 mm or more and 2 mm or less.

[0033] If the thickness is 0.1 mm or more, it is easy to ensure a predetermined inductance. If the thickness is 2 mm or less, leakage flux is small, and the effect of reducing eddy current loss is likely to be high.

[0034] (6) As one form of the above reactor, It is preferable to provide a molded resin portion that covers at least a portion of the magnetic core and that constitutes the gap portion.

[0035] In the reactor, the gap portion is formed of a molded resin portion, which makes it easy to maintain the gap between the end face of the first middle core portion and the end face of the second middle core portion, and also makes it easy to protect the magnetic core, which is covered by the molded resin portion, from the external environment.

[0036] In the reactor, it is easy to form the gap portion with a part of the molded resin portion. The reason is as follows. The gap portion formed with a part of the molded resin portion is formed as follows. An assembly is prepared by combining a coil and a magnetic core. The material constituting the molded resin portion is spread from the outside of the assembly toward the inside of the winding portion, between the end faces of the first middle core portion and the second middle core portion. When the total volume Va is 50 cm 3 Even in the above cases, if the length from the second end face to the gap portion is 0.49 times or less the length of the winding portion, the constituent material of the molded resin portion can be easily spread between the end faces.

[0037] (7) As one form of the reactor, The converter may be configured for an electric vehicle, a hybrid vehicle, or a fuel cell vehicle.

[0038] The reactor is suitable for forming the converter.

[0039] (8) As one form of the reactor, the powder compact is a compact of a raw material powder containing a soft magnetic powder, The content of the soft magnetic powder in the powder compact may be 85% by volume or more and 99% by volume or less.

[0040] The magnetic properties of the above-mentioned powder compact can be easily improved compared to a compact of a composite material.

[0041] (9) As one form of the reactor, The composite material molded body is a molded body in which soft magnetic powder is dispersed in a resin, The content of the soft magnetic powder in the compact of the composite material may be 20% by volume or more and 80% by volume or less.

[0042] The magnetic properties of the composite material compact can be adjusted more easily than with a powder compact, and it is also easy to form the composite material into a complex shape.

[0043] (10) A converter according to an embodiment of the present disclosure includes: The reactor is provided as described in any one of (1) to (9).

[0044] The converter includes the reactor, and therefore has excellent heat dissipation properties and low loss without being large in size.

[0045] (11) A power conversion device according to an embodiment of the present disclosure includes: The converter (10) is provided.

[0046] The power conversion device includes the converter, and therefore does not increase in size, has excellent heat dissipation properties, and has low loss.

[0047] Details of the embodiments of the present disclosure DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present disclosure will be described below with reference to the drawings, in which the same reference numerals indicate the same objects.

[0048] First Embodiment [Reactor] A reactor 1 of a first embodiment will be described with reference to Fig. 1 to Fig. 4. The reactor 1 includes a coil 2 and a magnetic core 3. The coil 2 has a winding portion 21. The number of winding portions 21 is one. One of the features of the reactor 1 of this embodiment is that it satisfies the following requirements (a) to (f).

[0049] (a) As shown in FIG. 2, outer peripheral surface 25 of winding portion 21 includes a portion that comes into contact with object 100 on which reactor 1 is to be installed. (b) As shown in Figure 1, the magnetic core 3 has an E-shaped first core portion 3f and a T-shaped second core portion 3s combined in the axial direction of the winding portion 21, and a gap portion 3g provided between the first core portion 3f and the second core portion 3s. (c) The first core portion 3f is made of a molded body of a composite material, and the second core portion 3s is made of a powder molded body. (d) The first middle core portion 31f provided in the first core portion 3f and the second middle core portion 31s provided in the second core portion 3s have specific lengths. (e) The gap portion 3g is located at a specific location. (f) The volume of the magnetic core 3 is a specific size.

[0050] Each component will be described in detail below. For ease of explanation, the coil 2 is indicated by a two-dot chain line in Figure 4. In the following description, a first direction D1, a second direction D2, and a third direction D3 defined as follows may be used. The first direction D1 is a direction along the axial direction of the winding portion 21. The second direction D2 is a direction along the parallel arrangement direction of a first middle core portion 31f, a first side core portion 321, and a second side core portion 322, which will be described later. The third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2.

[0051] [coil] As shown in Fig. 3, the coil 2 has a hollow winding portion 21. The winding portion 21 is formed by spirally winding a single wire without any joints. There is one winding portion 21. Because the reactor 1 of this embodiment has only one winding portion 21, the length along the second direction D2 can be made shorter than when multiple winding portions are arranged in parallel in a direction perpendicular to the axial direction of the winding portion.

[0052] The shape of the winding portion 21 is a rectangular cylinder. Rectangle includes oblong and square. The end face shape of the winding portion 21 in this embodiment is a rectangular frame shape. The rectangular cylinder shape of the winding portion 21 makes it easier to increase the contact area between the winding portion 21 and the installation target 100 compared to when the winding portion 21 is a circular cylinder with the same cross-sectional area. Therefore, the reactor 1 easily dissipates heat to the installation target 100 via the winding portion 21. Furthermore, it is easy to stably install the winding portion 21 on the installation target 100. Examples of the installation target 100 include a cooling base or the inner bottom surface of a case described below. The corners of the winding portion 21 are rounded. Unlike this embodiment, the shape of the winding portion 21 may be a circular cylinder. The circle includes a perfect circle and an ellipse.

[0053] Known windings can be used for the windings. The windings in this embodiment use coated rectangular wire. The conductor wire of the coated rectangular wire is made of copper rectangular wire. The insulating coating of the coated rectangular wire is made of enamel. The winding portion 21 is made of an edgewise coil in which the coated rectangular wire is wound edgewise.

[0054] In this embodiment, the first end 21a and the second end 21b of the winding portion 21 are extended toward the outer periphery of the winding portion 21 at the first end side and the second end side in the axial direction of the winding portion 21, respectively. Although not shown in the figure, the insulating coating of the first end 21a and the second end 21b is stripped to expose the conductor wire. As shown in FIG. 2, in this embodiment, the exposed conductor wire is drawn to the outside of the molded resin portion 4, which will be described later. A terminal member is connected to the exposed conductor wire. The terminal member is not shown. An external device is connected to the coil 2 via this terminal member. The external device is not shown. An example of the external device is a power source that supplies power to the coil 2.

[0055] The outer peripheral surface 25 of the winding portion 21 has a portion that contacts the installation target 100 of the reactor 1. This facilitates heat dissipation of the reactor 1. The outer peripheral surface 25 has a portion that protrudes in the third direction D3 beyond the magnetic core 3. That is, the length of the winding portion 21 along the third direction D3 is longer than the length of the magnetic core 3 along the third direction D3. In this embodiment, the winding portion 21 has a rectangular cylindrical shape, and therefore the outer peripheral surface 25 of the winding portion 21 has four flat surfaces. In this embodiment, one of the four flat surfaces is the portion that contacts the installation target 100. This ensures that the winding portion 21 has a sufficient contact area with the installation target 100. This facilitates heat dissipation of the reactor 1. In this embodiment, the contacting portion of the winding portion 21 is exposed from the molded resin portion 4, which will be described later. This facilitates heat dissipation of the coil 2 via the installation target 100.

[0056] [Magnetic core] As shown in FIG. 1, the magnetic core 3 is an assembly in which a first core portion 3f and a second core portion 3s are combined in a first direction D1. A gap portion 3g, which will be described later, is provided between the first core portion 3f and the second core portion 3s. Since the magnetic core 3 can be constructed by combining the first core portion 3f and the second core portion 3s in the first direction D1, the reactor 1 has excellent manufacturing workability. The combination of the first core portion 3f and the second core portion 3s is an ET type. This combination makes it easier to adjust the inductance and heat dissipation. The first core portion 3f is made of a molded body of a composite material, which will be described later. The second core portion 3s is made of a powder compact, which will be described later.

[0057] The total volume Va of the first core portion 3f, the second core portion 3s, and the gap portion 3g is 50 cm 3 More than 500cm 3 The total volume V is 50 cm 3 More than 500cm 3 The reactor 1 having the following structure is suitable for a converter of an electric vehicle, a hybrid vehicle, or a fuel cell vehicle. Since the winding portion 21 has a portion that contacts the installation target 100 and the second core portion 3s is made of a powder compact, the total volume Va is 50 cm 3 Even if the total volume Va is 500 cm or more, the heat of the magnetic core 3 is easily released. 3 By keeping the total volume Va at 60 cm or less, the reactor 1 is unlikely to become excessively large. 3 More than 400cm 3 Below 70cm 3 More than 300cm 3 The volume of the gap portion 3g is the volume of the space surrounded by the end faces of the first middle core portion 31f, the end faces of the second middle core portion 31s, and a virtual outer circumferential surface. The virtual outer circumferential surface is the outer circumferential surface obtained by extending the outer circumferential surface of the first middle core portion 31f in the first direction D1.

[0058] (First core part) As shown in FIG. 4, the planar shape of the first core portion 3f is E-shaped. The planar shape of the first core portion 3f refers to the shape of the first core portion 3f when viewed from the third direction D3. The concept of planar shape is similar to that of the second core portion 3s described later. The first core portion 3f has a first end core portion 33f, a first middle core portion 31f, a first side core portion 321, and a second side core portion 322. The first end core portion 33f faces a first end face of the winding portion 21. Facing means that the first end core portion 33f and the first end face of the winding portion 21 face each other. The first middle core portion 31f has a portion disposed inside the winding portion 21. The first side core portion 321 and the second side core portion 322 are disposed facing each other with the first middle core portion 31f sandwiched therebetween. The first side core portion 321 and the second side core portion 322 are disposed on the outer periphery of the winding portion 21.

[0059] As shown in Fig. 3, the first core portion 3f is a molded body formed integrally with a first end core portion 33f, a first middle core portion 31f, a first side core portion 321, and a second side core portion 322. The first end core portion 33f connects the first middle core portion 31f, the first side core portion 321, and the second side core portion 322. The first side core portion 321 and the second side core portion 322 are provided at both ends of the first end core portion 33f. The first middle core portion 31f is provided in the center of the first end core portion 33f. The first core portion 3f is composed of a molded body made of a composite material, which will be described later.

[0060] In this embodiment, the shape of the first end core portion 33f is a thin rectangular column. The shape of the first middle core portion 31f corresponds to the inner peripheral shape of the winding portion 21. In this embodiment, the shape of the first middle core portion 31f is a quadrangular column. Although the corners of the first middle core portion 31f are shown as angular in FIG. 3, they are rounded to fit the inner peripheral surface of the corners of the winding portion 21. The shapes of the first side core portion 321 and the second side core portion 322 are the same. In this embodiment, the shapes of the first side core portion 321 and the second side core portion 322 are thin rectangular columns.

[0061] The sum of the cross-sectional area of ​​the first side core portion 321 and the cross-sectional area of ​​the second side core portion 322 is the same as the cross-sectional area of ​​the first middle core portion 31f and the cross-sectional area of ​​the second middle core portion 31s. The cross-sectional area here refers to the cross-sectional area of ​​a cross section perpendicular to the first direction D1.

[0062] As shown in FIG. 4, the length L1f of the first middle core portion 31f along the first direction D1 is shorter than the length of the wound portion 21 along the first direction D1. The length of the wound portion 21 along the first direction D1 is the length along the first direction D1 between the first end face and the second end face of the wound portion 21. If there are gaps between the turns of the wound portion 21, the length of the wound portion 21 along the first direction D1 includes the length of the gaps between the turns. The length of the first middle core portion 31f along the second direction D2 is longer than the length of the first side core portion 321 along the second direction D2 and the length of the second side core portion 322 along the second direction D2. As shown in FIG. 1, the length of the first middle core portion 31f along the third direction D3 is the same as the length of the first side core portion 321 along the third direction D3 and the length of the second side core portion 322 along the third direction D3.

[0063] As shown in Fig. 4, the length L21f of the first side core portion 321 along the first direction D1 and the length L22f of the second side core portion 322 along the first direction D1 are the same. The lengths L21f and L22f are longer than the length L1f and longer than the length of the winding portion 21 along the first direction D1. The length of the first side core portion 321 along the second direction D2 and the length of the second side core portion 322 along the second direction D2 are the same. As shown in Fig. 1, the length of the first side core portion 321 along the third direction D3 and the length of the second side core portion 322 along the third direction D3 are the same.

[0064] (Second core part) As shown in Fig. 4, the second core portion 3s has a T-shape in plan view. The second core portion 3s has a second end core portion 33s and a second middle core portion 31s. The second end core portion 33s faces the second end face of the winding portion 21. "Facing" means that the second end core portion 33s and the second end face of the winding portion 21 face each other. The second middle core portion 31s has a portion that is disposed inside the winding portion 21.

[0065] As shown in FIG. 3, the second core portion 3s is a molded body formed by integrating a second end core portion 33s and a second middle core portion 31s. The second middle core portion 31s is provided at the center of the second end core portion 33s. The second core portion 3s is composed of a powder compact, which will be described later. A T-shaped powder compact is easier to manufacture than an E-shaped powder compact. Therefore, a T-shaped powder compact is easier to manufacture with high precision than an E-shaped powder compact. Therefore, when combined with the first core portion 3f, a T-shaped second core portion 3s is less likely to have an unnecessary gap than an E-shaped second core portion 3s.

[0066] The shape of the second end core portion 33s is the same as the shape of the first end core portion 33f. That is, the second end core portion 33s is a thin rectangular column. The shape of the second middle core portion 31s is a quadrangular column. The corners of the second middle core portion 31s are rounded to fit the inner circumferential surface of the corners of the winding portion 21.

[0067] As shown in FIG. 4, the length L1s of the second middle core portion 31s along the first direction D1 is shorter than the length L1f. The sum of the lengths L1s and L1f is shorter than each of the lengths L21f and L22f. The length of the second middle core portion 31s along the second direction D2 is the same as the length of the first middle core portion 31f along the second direction D2. As shown in FIG. 1, the length of the second middle core portion 31s along the third direction D3 is the same as the length of the first middle core portion 31f along the third direction D3.

[0068] As shown in FIG. 4, the length L3s of the second end core portion 33s along the first direction D1 is the same as the length L3f of the first end core portion 33f along the first direction D1. The length of the second end core portion 33s along the second direction D2 is the same as the length of the first end core portion 33f along the second direction D2. The length of the second end core portion 33s along the second direction D2 is longer than the length of the wound portion 21 along the second direction D2. As shown in FIG. 1, the length of the second end core portion 33s along the third direction D3 is the same as the length of the first end core portion 33f along the third direction D3. As shown in FIG. 2, the length of the second end core portion 33s along the third direction D3 is shorter than the length of the wound portion 21 along the third direction D3. As shown in FIG. 1, the length of the second end core portion 33s along the third direction D3 is the same as the length of the second middle core portion 31s along the third direction D3.

[0069] An example of the volume ratio Vps calculated by (volume Vs / total volume Va) × 100 is 25% or more and 40% or less. The volume Vs is the volume of the second core portion 3s. As described above, the total volume Va is the total volume of the first core portion 3f, the second core portion 3s, and the gap portion 3g. If the volume ratio Vps is 25% or more, the heat dissipation performance of the reactor 1 is likely to be improved. If the volume ratio Vps is 40% or less, the loss of the reactor 1 is likely to be reduced. The volume ratio Vps is further preferably 27% or more and 38% or less, and particularly preferably 29% or more and 36% or less.

[0070] An example of the volume ratio Vpm calculated by (volume Vms / total volume Vma)×100 is 15% or more and 49% or less. The volume Vms is the volume of the second middle core portion 31s. The total volume Vma is the total volume of the first middle core portion 31f, the second middle core portion 31s, and the gap portion 3g. If the ratio Vpm is 15% or more, the heat dissipation performance of the reactor 1 is likely to be improved. If the ratio Vpm is 49% or less, the loss of the reactor 1 is likely to be reduced. The ratio Vpm is furthermore 20% or more and 40% or less, and particularly 25% or more and 35% or less.

[0071] The first core portion 3f and the second core portion 3s are combined so that the end faces of the first side core portion 321 and the second side core portion 322 are in contact with the end face of the second end core portion 33s. A gap is provided between the end face of the first middle core portion 31f and the end face of the second middle core portion 31s. A gap portion 3g, which will be described later, is provided between the end face of the first middle core portion 31f and the end face of the second middle core portion 31s.

[0072] The composite material green compact constituting the first core portion 3f is a green compact in which soft magnetic powder is dispersed in resin. The composite material green compact is obtained by filling a mold with a fluid material in which soft magnetic powder is dispersed in unsolidified resin and then solidifying the resin. The content of soft magnetic powder in the resin of the composite material green compact can be easily adjusted. Therefore, the magnetic properties of the composite material green compact are easy to adjust. Furthermore, the composite material green compact can be easily formed into complex shapes compared to pressed powder green compacts. An example of the content of soft magnetic powder in the composite material green compact is 20% by volume or more and 80% by volume or less. An example of the content of resin in the composite material green compact is 20% by volume or more and 80% by volume or less. These contents are values ​​when the composite material green compact is 100% by volume.

[0073] The powder compact constituting the second core portion 3s is a compact formed by compressing and molding soft magnetic powder. Compared to a compact made of a composite material, a powder compact can have a higher ratio of soft magnetic powder in the core portion. Therefore, the powder compact is easy to improve its magnetic properties. Examples of magnetic properties include relative permeability and saturation magnetic flux density. Furthermore, compared to a compact made of a composite material, the powder compact has a lower amount of resin and a higher amount of soft magnetic powder, and therefore has excellent heat dissipation properties. An example of the content of magnetic powder in the powder compact is 85% by volume or more and 99% by volume or less. This content is the value when the powder compact is 100% by volume.

[0074] Examples of particles constituting the soft magnetic powder include soft magnetic metal particles, coated particles, and soft magnetic non-metal particles. The coated particles include soft magnetic metal particles and an insulating coating provided on the outer periphery of the soft magnetic 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.

[0075] Examples of resins for composite material molded bodies include 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 fluororesins. Examples of polyamide resins include nylon 6, nylon 66, and nylon 9T.

[0076] The composite material compact may contain a ceramic filler, such as alumina or silica, which contributes to improving heat dissipation and electrical insulation.

[0077] The content of soft magnetic powder in the composite material compact and the content of soft magnetic powder in the powder compact are considered to be equivalent to the area ratio of the soft magnetic powder in the cross section of the compact. The content of soft magnetic powder in the compact is determined as follows: The cross section of the compact is observed with a SEM (scanning electron microscope) to obtain an observation image. The cross section of the compact is any cross section. The magnification of the SEM is 200 times or more and 500 times or less. At least 10 observation images are obtained. The total cross section area is 0.1 cm 2 That is all. One observation image may be acquired per cross section, or multiple observation images may be acquired per cross section. Each acquired observation image is subjected to image processing to extract the particle contours. Image processing includes, for example, binarization. The area ratio of soft magnetic particles in each observation image is calculated, and the average value of these area ratios is determined. This average value is considered to be the content of soft magnetic powder.

[0078] As described above, the first core portion 3f is made of a composite material molded body, and the second core portion 3s is made of a powder compact. By making the first core portion 3f a composite material molded body and the second core portion 3s a powder compact, it is easy to adjust the inductance without using the long gap portion 3g, and it is also easy to adjust the heat dissipation. Furthermore, in the reactor 1, the second core portion 3s is made of a powder compact with a relatively high thermal conductivity, which makes it easy to improve the heat dissipation.

[0079] (Gap part) The gap portion 3g is located inside the winding portion 21. The gap portion 3g is located between the end face of the first middle core portion 31f and the end face of the second middle core portion 31s. Because the gap portion 3g is located inside the winding portion 21, leakage magnetic flux is less likely to enter the winding portion 21 than if the gap portion 3g were located outside the winding portion 21. This makes it easier to reduce eddy current loss generated in the winding portion 21. The gap portion 3g is made of a material with a lower relative magnetic permeability than the first core portion 3f and the second core portion 3s. In this embodiment, the gap portion 3g is made of a part of the molded resin portion 4, which will be described later.

[0080] An example of the ratio of the thickness of the gap portion 3g to the total length of the length L1f, the length L1s, and the thickness of the gap portion 3g is 0.001 or more and 0.1 or less. The thickness of the gap portion 3g is the length Lg of the gap portion 3g along the first direction D1. If the ratio is 0.001 or more, it is easy to ensure a predetermined inductance. If the ratio is 0.1 or less, there is little leakage magnetic flux, and the effect of reducing eddy current loss is likely to be high. The ratio is further preferably 0.01 or more and 0.08 or less, and particularly preferably 0.02 or more and 0.06 or less.

[0081] An example of the thickness of the gap portion 3g is 0.1 mm or more and 2 mm or less. If the thickness is 0.1 mm or more, it is easy to ensure a predetermined inductance. If the thickness is 2 mm or less, leakage magnetic flux is small and the effect of reducing eddy current loss is likely to be high. The thickness is further 0.3 mm or more and 1.75 mm or less, and particularly 0.5 mm or more and 1.5 mm or less.

[0082] An example of the length Le along the first direction D1 from the second end face of the winding portion 21 to the gap portion 3g is 0.2 to 0.49 times the length along the first direction D1 of the winding portion 21. The length Le is the length along the first direction D1 between the position in the gap portion 3g closest to the second end face and the second end face.

[0083] When the length Le is 0.2 times or more the length of the winding portion 21 in the first direction D1, leakage magnetic flux is less likely to enter the winding portion 21. This makes it easier to reduce eddy current loss that occurs in the winding portion 21. The closer the length Le is to 0.5 times the length of the winding portion 21 in the first direction D1, that is, the closer the position of the gap portion 3g is to the center of the winding portion 21 in the first direction D1, the greater the effect of reducing eddy current loss is likely to be.

[0084] When the length Le is 0.49 times or less the length of the winding portion 21 along the first direction D1, it is possible to increase the proportion of the compact made of the composite material, which has lower loss than the powder compact, and therefore the reactor 1 has low loss. Furthermore, when the length Le is 0.49 times or less the length of the winding portion 21 along the first direction D1, it is easy to fabricate the gap portion 3g configured by a part of the molded resin portion 4. The gap portion 3g configured by a part of the molded resin portion 4 is formed as follows: An assembly is prepared in which the coil 2 and the magnetic core 3 are combined. The constituent material of the molded resin portion 4 is spread from the outside of the assembly toward the space between the end faces of the first middle core portion 31f and the second middle core portion 31s inside the winding portion 21. When the length Le is 0.49 times or less the length of the winding portion 21 along the first direction D1, the total volume Va is 50 cm 3 Even in this case, it is easy to spread the constituent material of the molded resin portion 4 between the end faces. The shorter the length Le, the easier it is to spread the constituent material of the molded resin portion 4 between the end faces.

[0085] The length Le is further 0.2 to 0.4 times the length of the wound portion 21 along the first direction D1, and particularly 0.25 to 0.375 times the length of the wound portion 21 along the first direction D1.

[0086] [Molded resin part] 1, the molded resin part 4 covers at least a portion of the magnetic core 3 and defines a gap part 3g. The molded resin part 4 may cover the outer periphery of the magnetic core 3 but not the outer periphery of the coil 2, or may cover both the outer periphery of the magnetic core 3 and the outer periphery of the coil 2. For ease of explanation, the molded resin part 4, which will be described later, is omitted from FIG. 4.

[0087] As shown in FIG. 2 , the molded resin portion 4 in this embodiment covers the outer periphery of the assembly of a portion of the coil 2 and the magnetic core 3. This effectively protects the assembly from the external environment. In this embodiment, the flat surface of the outer periphery of the coil 2 facing the installation target is exposed from the molded resin portion 4. The entire outer periphery of the coil 2, excluding the flat surface facing the installation target, is covered by the molded resin portion 4. The entire outer periphery of the magnetic core 3 is covered by the molded resin portion 4. The molded resin portion 4 is provided between the winding portion 21 and the first middle core portion 31f, between the winding portion 21 and the second middle core portion 31s, and between the end face of the first middle core portion 31f and the end face of the second middle core portion 31s. The molded resin portion 4 integrates the coil 2 and the magnetic core 3. An example of the resin of the molded resin portion 4 is the same resin as the resin of the composite material compact described above. The resin of the molded resin portion 4 may contain a ceramic filler, as in the composite material compact.

[0088] [others] Although not shown, the reactor 1 may include at least one of a case, an adhesive layer, and a holding member. The case houses the assembly of the coil 2 and the magnetic core 3 inside. The assembly inside the case may be embedded in a sealing resin portion. The case is placed on a cooling base or the like. The adhesive layer fixes the assembly to the cooling base or the inner bottom surface of the case, or fixes the case to the cooling base or the like. The holding member is placed between the coil 2 and the magnetic core 3 and ensures insulation between the coil 2 and the magnetic core 3.

[0089] [Effects of the First Embodiment] The reactor 1 of this embodiment can achieve the following effects.

[0090] The inductance of the reactor 1 can be easily adjusted without increasing the thickness of the gap portion 3g because the magnetic core 3 is not made of a single material but is made of a first core portion 3f made of a composite material compact and a second core portion 3s made of a powder compact.

[0091] The reactor 1 has an improved heat dissipation property because the winding portion 21 includes a portion that contacts the installation target 100, and thus the heat of the coil 2 can be effectively dissipated via the installation target 100. Also, this is because the surface of the magnetic core 3 can include a surface made of a powder compact with a relatively high thermal conductivity.

[0092] The reactor 1 can be suitably used as a reactor cooled by a cooling member with uneven cooling performance. The second core portion 3s, which has high thermal conductivity, is arranged on the side of the cooling member with low cooling performance, and the first core portion 3f, which has low thermal conductivity, is arranged on the side of the cooling member with high cooling performance. This allows the first core portion 3f and the second core portion 3s to be cooled evenly, reducing the maximum temperature of the magnetic core 3.

[0093] The reactor 1 is difficult to increase in size. This is because the reactor 1 has an easily adjustable and easily increased heat dissipation property, as described above, and therefore does not require a cooling pipe as in the conventional reactor described above.

[0094] The reactor 1 has low loss. This is because the length L1s is shorter than the length L1f, which reduces the proportion of powder compacts, which have higher loss than the composite material compact. Furthermore, the gap 3g is disposed inside the winding portion 21, and the length Le is 0.2 times or more the length of the winding portion 21, which makes it difficult for leakage magnetic flux to penetrate the winding portion 21. This makes it easy to reduce eddy current loss generated in the winding portion 21. Furthermore, the length Le is 0.49 times or less the length of the winding portion 21, which makes it possible to increase the proportion of composite material compacts, which have lower loss than the powder compact, inside the winding portion 21. And, as described above, the maximum temperature of the magnetic core 3 is reduced.

[0095] Reactor 1 can suppress problems such as the influence of leakage magnetic flux on peripheral devices. This is because gap 3g is disposed inside winding portion 21 and length Le is 0.2 times or more the length of winding portion 21, which makes it easy to suppress leakage of magnetic flux to the outside of winding portion 21.

[0096] In reactor 1, gap 3g is easily formed in part of molded resin portion 4. Length Le is 0.49 times or less the length of winding portion 21. In other words, the gap that becomes gap 3g is close to the second end face of winding portion 21. Therefore, when total volume Va is 50 cm 3 Even with the above, the constituent material of the molded resin portion can be easily spread between the end faces of the first middle core portion 31f and the second middle core portion 31s inside the winding portion 21.

[0097] Second Embodiment [Converter / Power Conversion Device] The reactor 1 of the first embodiment can be used in applications that satisfy the following energization conditions. Examples of the energization conditions include a maximum DC current of approximately 100 A to 1000 A, an average voltage of approximately 100 V to 1000 V, and an operating frequency of approximately 5 kHz to 100 kHz. The reactor 1 of the first embodiment can be used as a component of a converter mounted on a vehicle 1200, such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, or as a component of a power conversion device equipped with this converter.

[0098] As shown in Fig. 5, the vehicle 1200 includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and a motor 1220 that is driven by power supplied from the main battery 1210 and used for traveling. The motor 1220 is typically a three-phase AC motor that drives wheels 1250 when traveling and functions as a generator when regenerating power. In the case of a hybrid vehicle, the vehicle 1200 includes an engine 1300 in addition to the motor 1220. Although Fig. 5 shows an inlet as a charging point for the vehicle 1200, a form including a plug may also be used.

[0099] 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, which is approximately 200 V or more and 300 V or less, to approximately 400 V or more and 700 V or less, when the vehicle 1200 is running, and supplies the voltage to the inverter 1120. During regeneration, the converter 1110 reduces the input voltage output from the motor 1220 via the inverter 1120 to a direct current voltage suitable for the main battery 1210, and charges the main battery 1210. The input voltage is a direct current voltage. When the vehicle 1200 is running, the inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC and supplies it to the motor 1220, and when regenerating, it converts the AC output from the motor 1220 into DC and outputs it to the converter 1110.

[0100] As shown in FIG. 6 , the converter 1110 includes multiple switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115. The converter converts the input voltage by repeatedly switching the switching elements 1111 on and off. The conversion of the input voltage here refers to boosting and bucking the voltage. The switching elements 1111 are power devices such as field-effect transistors and insulated gate bipolar transistors. The reactor 1115 utilizes the properties of a coil that hinders changes in current flowing through a circuit, and has the function of smoothing changes in current that increase or decrease due to switching operations. The reactor 1115 includes the reactor 1 of the first embodiment. By including the reactor 1, which has excellent heat dissipation properties and low loss without increasing the size, the power conversion device 1100 and the converter 1110 can also be expected to be smaller, have improved heat dissipation properties, and reduce loss.

[0101] In addition to converter 1110, vehicle 1200 includes a power supply converter 1150 connected to main battery 1210, and an auxiliary power supply converter 1160 connected to main battery 1210 and sub-battery 1230, which serves as a power source for auxiliary equipment 1240, and converts the high voltage of main battery 1210 to low voltage. Converter 1110 typically performs DC-DC conversion, while power supply converter 1150 and auxiliary power supply converter 1160 perform AC-DC conversion. Some power supply converters 1150 perform DC-DC conversion. A reactor having a configuration similar to reactor 1 of embodiment 1 or the like but with a modified size, shape, or the like can be used as the reactor for power supply converter 1150 and auxiliary power supply converter 1160. Furthermore, reactor 1 of embodiment 1 or the like can also be used as a converter that converts input power, and that only boosts or only bucks the voltage.

[0102] The present invention is not limited to these examples, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0103] 1 reactor 2 coils, 21 winding portion, 21a first end portion, 21b second end portion, 25 Outer surface 3 magnetic core, 3f first core part, 3s second core part 31f First middle core part, 31s Second middle core part 321 first side core portion, 322 second side core portion 33f First end core part, 33s Second end core part 3g Gap section 4 Molded resin part L1f, L1s, L21f, L22f, L3f, L3s, Le length D1 first direction, D2 second direction, D3 third direction 100 Installation targets 1100 Power Converter, 1110 Converter 1111 switching element, 1112 drive circuit, 1115 reactor 1120 Inverter 1150 Power supply converter, 1160 Auxiliary power supply converter 1200 vehicles 1210 Main battery, 1220 Motor, 1230 Sub battery 1240 Auxiliary equipment, 1250 Wheels 1300 Engine

Claims

1. A reactor including a coil and a magnetic core, the coil has a winding portion; the number of the winding portions is one, an outer circumferential surface of the winding portion includes a portion that comes into contact with an object on which the reactor is to be installed, The magnetic core is an E-shaped first core portion and a T-shaped second core portion combined in the axial direction of the winding portion; a gap portion provided between the first core portion and the second core portion, the first core portion is composed of a molded body of a composite material, which is an integral body including a first end core portion facing a first end face of the winding portion, a first middle core portion having a portion disposed inside the winding portion, and a first side core portion and a second side core portion disposed on the outer periphery of the winding portion so as to sandwich the first middle core portion, the second core portion is composed of a powder-compressed compact integrally formed with a second end core portion facing the second end surface of the winding portion and a second middle core portion having a portion disposed inside the winding portion, a length of the second middle core portion along the axial direction of the winding portion is shorter than a length of the first middle core portion along the axial direction of the winding portion, the gap portion is disposed inside the winding portion between the first middle core portion and the second middle core portion, a length from the second end surface to the gap portion is 0.2 times or more and 0.49 times or less the length of the winding portion, The total volume Va of the first core portion, the second core portion, and the gap portion is 50 cm ３ More than 500cm ３ Below is the Reactor.

2. The reactor according to claim 1 , wherein a ratio of a volume of the second core portion to the total volume Va is equal to or greater than 25% and equal to or less than 40%.

3. 3. The reactor according to claim 1, wherein a ratio of the volume of the second middle core portion to a total volume of the first middle core portion, the second middle core portion, and the gap portion is 15% or more and 49% or less.

4. 4. The reactor according to claim 1, wherein a ratio of the thickness of the gap portion to a total length of the first middle core portion, the second middle core portion, and the thickness of the gap portion is 0.001 or more and 0.1 or less.

5. The reactor according to claim 1 , wherein the gap portion has a thickness of 0.1 mm or more and 2 mm or less.

6. The reactor according to claim 1 , further comprising a molded resin portion that covers at least a portion of the magnetic core and that constitutes the gap portion.

7. The reactor according to any one of claims 1 to 6, which constitutes a converter of an electric vehicle, a hybrid vehicle, or a fuel cell vehicle.

8. the powder compact is a compact of a raw material powder containing a soft magnetic powder, The reactor according to claim 1 , wherein the content of the soft magnetic powder in the powder compact is 85% by volume or more and 99% by volume or less.

9. The composite material molded body is a molded body in which soft magnetic powder is dispersed in a resin, 9. The reactor according to claim 1, wherein the content of the soft magnetic powder in the compact of the composite material is 20% by volume or more and 80% by volume or less.

10. A reactor according to any one of claims 1 to 9, converter.

11. A converter according to claim 10, Power conversion device.

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