Reactor, converter, and power conversion device

Abstract

To provide a reactor capable of reducing loss of a coil.SOLUTION: A reactor includes a coil and a magnetic core, wherein the magnetic core includes a first core and a second core, the first core includes a first end core part and at least a part of a side core part, the second core includes a second end core part and the remainder of the side core part, at least one of the first core and the second core includes at least a part of a middle core part, the side core part is arranged in parallel with the middle core part so as to sandwich the coil, the first core is composed of a molding of a composite material where soft magnetic powder is dispersed in the resin, the first end core part has an inside surface, an outside surface and a projection provided on the outside surface, the projection includes a first projection and a second projection, the first projection is provided in a part corresponding between the middle core part and the first side core part, and the second projection is provided in a part corresponding between the middle core part and the second side core part.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] A reactor is a component of a converter mounted on a vehicle such as a hybrid vehicle. The reactor includes a coil and a magnetic core. The reactor shown in Figs. 5 to 8 of Patent Document 1 includes one coil and a magnetic core formed by combining two core pieces. This magnetic core is a so-called EE-type core consisting of two E-shaped core pieces. This magnetic core is configured in a θ-shape by combining the two core pieces so that their end faces face each other. The magnetic core has an end core portion, a middle core portion, and a side core portion. The end core portion is disposed so as to face the end face of the coil. The middle core portion is disposed inside the coil. The side core portion is disposed in parallel with the middle core portion so as to sandwich the coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-201509 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to reduce coil losses due to leakage flux from the magnetic core.

[0005] An object of the present disclosure is to provide a reactor capable of reducing coil loss. [Means for solving the problem]

[0006] The reactor of the present disclosure includes: The coil has a cylindrical shape and a magnetic core has a θ shape. the coil has a first end surface and a second end surface; The magnetic core includes a first core and a second core, The first core includes a first end core portion and at least a portion of a side core portion, the second core includes a second end core portion and a remainder of the side core portion, At least one of the first core and the second core includes at least a portion of a middle core portion, the first end core portion is disposed to face the first end surface of the coil, the second end core portion is disposed to face the second end surface of the coil, The middle core portion is disposed within the coil, the side core portion includes a first side core portion and a second side core portion arranged in parallel with the middle core portion so as to sandwich the coil therebetween, The first core is formed of a composite material molded body in which soft magnetic powder is dispersed in a resin, The first end core portion is an inner surface to which first ends of the middle core portion, the first side core portion, and the second side core portion are joined; An outer surface facing away from the inner surface; a protrusion provided on the outer surface, The protrusion includes a first protrusion and a second protrusion, the first protruding portion is provided on the outer surface at a position corresponding to a position between the middle core portion and the first side core portion, The second protruding portion is provided on the outer surface at a location corresponding to a position between the middle core portion and the second side core portion. Effect of the Invention

[0007] The reactor of the present disclosure can reduce coil loss. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 is a schematic perspective view showing a reactor according to the first embodiment. [Diagram 2] FIG. 2 is a schematic plan view showing the reactor according to the first embodiment. [Diagram 3] FIG. 3 is a schematic plan view showing an enlarged view of a main part of the reactor shown in FIG. [Figure 4] FIG. 4 is a schematic perspective view showing a first modification of the reactor according to the first embodiment. [Diagram 5] FIG. 5 is a schematic perspective view showing a second modification of the reactor according to the first embodiment. [Figure 6] FIG. 6 is a schematic plan view showing the reactor according to the second embodiment. [Figure 7] FIG. 7 is a schematic plan view showing half of the reactor shown in FIG. [Figure 8] FIG. 8 is a schematic plan view showing a modified example of the reactor according to the second embodiment. [Figure 9] FIG. 9 is a schematic plan view showing half of the reactor shown in FIG. [Figure 10] FIG. 10 is a schematic diagram showing a power supply system of a hybrid vehicle. [Figure 11] FIG. 11 is a circuit diagram that illustrates a power conversion device including a converter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described.

[0010] (1) The reactor of the present disclosure is The coil has a cylindrical shape and a magnetic core has a θ shape. the coil has a first end surface and a second end surface; The magnetic core includes a first core and a second core, The first core includes a first end core portion and at least a portion of a side core portion, the second core includes a second end core portion and a remainder of the side core portion, At least one of the first core and the second core includes at least a portion of a middle core portion, the first end core portion is disposed to face the first end surface of the coil, the second end core portion is disposed to face the second end surface of the coil, The middle core portion is disposed within the coil, the side core portion includes a first side core portion and a second side core portion arranged in parallel with the middle core portion so as to sandwich the coil therebetween, The first core is formed of a composite material molded body in which soft magnetic powder is dispersed in a resin, The first end core portion is an inner surface to which first ends of the middle core portion, the first side core portion, and the second side core portion are joined; An outer surface facing away from the inner surface; a protrusion provided on the outer surface, The protrusion includes a first protrusion and a second protrusion, the first protruding portion is provided on the outer surface at a position corresponding to a position between the middle core portion and the first side core portion, The second protruding portion is provided on the outer surface at a location corresponding to a position between the middle core portion and the second side core portion.

[0011] The reactor of the present disclosure can reduce coil loss. In general, the relative magnetic permeability of a composite material molded body is low. Therefore, when the first core is composed of a composite material molded body, leakage magnetic flux is likely to occur from the first end core portion. This leakage magnetic flux links with the coil, causing loss in the coil. According to the reactor of the present disclosure, the magnetic path area of ​​the first end core portion is increased by providing a protruding portion on the outer surface of the first end core portion. Since leakage magnetic flux is unlikely to occur from the first end core portion, leakage magnetic flux linking with the coil can be suppressed. As a result of the reduction in leakage magnetic flux to the coil, coil loss can be reduced. In particular, since the first protruding portion and the second protruding portion are provided at specific locations on the outer surface of the first end core portion, leakage magnetic flux from the first end core portion to the coil can be effectively suppressed, thereby effectively reducing coil loss.

[0012] (2) In the reactor described in (1) above, The length of the first protruding portion and the length of the second protruding portion may each be 0.05 to 0.5 times the length of the first end core portion.

[0013] The above configuration (2) can effectively reduce coil loss without suppressing an increase in the volume of the first core. The length of each protrusion is 0.05 times or more the length of the first end core portion, so that leakage magnetic flux from the first end core portion to the coil can be effectively suppressed. The length of each protrusion is 0.5 times or less the length of the first end core portion, so that an increase in the volume of the first end core portion can be suppressed.

[0014] (3) In the reactor according to (1) or (2), a width of the first protruding portion is 0.2 to 1.0 times the distance between the middle core portion and the first side core portion, The width of the second protruding portion may be 0.2 to 1.0 times the distance between the middle core portion and the second side core portion.

[0015] The above configuration (3) can effectively reduce coil loss without suppressing an increase in the volume of the first core. The width of each protrusion is 0.2 times or more the distance between the middle core portion and each side core portion, so that leakage magnetic flux from the first end core portion to the coil can be effectively suppressed. The width of each protrusion is 1.0 times or less the distance between the middle core portion and each side core portion, so that an increase in the volume of the first end core portion can be suppressed.

[0016] (4) In the reactor according to any one of (1) to (3), The first core may have a relative magnetic permeability of 5 or more and 50 or less.

[0017] The above configuration (4) makes it easy to obtain a predetermined inductance.

[0018] (5) In the reactor according to any one of (1) to (4), The middle core portion has a first middle core portion and a second middle core portion, the first middle core portion is connected to the first end core portion, The second middle core portion may be joined to the second end core portion.

[0019] The above configuration (5) can differentiate the magnetic characteristics of the first middle core portion from the second middle core portion, allowing the magnetic characteristics of the entire magnetic core to be adjusted.

[0020] (6) In the reactor described in (5) above, The middle core portion may have a gap portion between the first middle core portion and the second middle core portion.

[0021] The above configuration (6) makes it possible to adjust the magnetic characteristics of the entire magnetic core by using the gap portion.

[0022] (7) In the reactor according to any one of (1) to (6), The first core includes the entire side core portion, the relative permeability of the first core is lower than the relative permeability of the second core, the first side core portion and the second side core portion each have a first end joined to the first end core portion and a second end joined to the second end core portion, a first distance between the first side core portion and the coil and a second distance between the second side core portion and the coil at the second end are larger than a first distance at the first end, The ratio of the first interval to the second interval may be equal to or greater than 0.32 and equal to or less than 0.70.

[0023] The configuration of (7) above can further reduce the loss of the coil. When the relative permeability of the side core portion is low and the relative permeability of the second end core portion is high, leakage flux may occur in the region near the second end, shortcutting from the side core portion to the second end core portion. This leakage flux links with the coil, causing loss in the coil. According to the configuration of (7) above, the second interval at the second end is larger than the first interval at the first end, so that the leakage flux linking with the coil can be suppressed. Since the leakage flux to the coil is reduced, the loss of the coil can be reduced. Since the ratio of the first interval to the second interval is 0.70 or less, the leakage flux to the coil is sufficiently suppressed, so that the loss of the coil can be effectively reduced. In particular, when the ratio of the first interval to the second interval is 0.32 or more and 0.70 or less, the loss of the coil can be effectively reduced while suppressing the decrease in inductance.

[0024] The magnetic properties of the entire magnetic core can be adjusted by making the magnetic properties of the first core different from that of the second core. The relative magnetic permeability of the first core is lower than that of the second core, making it easier to obtain a predetermined inductance.

[0025] (8) In the reactor described in (7) above, The first side core portion and the second side core portion may each have a tapered shape whose width decreases from the first end to the second end.

[0026] The above configuration (8) makes it easy to reduce coil loss.

[0027] (9) In the reactor described in (7) above, The first side core portion and the second side core portion may each have a stepped shape whose width narrows from the first end to the second end.

[0028] The above configuration (9) makes it easy to reduce coil loss.

[0029] (10) In the reactor according to any one of (1) to (9), The second core may have a relative magnetic permeability of 100 or more and 500 or less.

[0030] The above configuration (10) makes it easy to obtain a predetermined inductance.

[0031] (11) In the reactor according to any one of (1) to (10), The second core may be formed of a powder compact.

[0032] Generally, the powder compact has a high relative magnetic permeability. The above configuration (11) makes it easy to configure a magnetic core in which the relative magnetic permeability of the first core is lower than that of the second core. By configuring the second core from the powder compact, it is easy to adjust the relative magnetic permeability of the second core to, for example, 100 or more and 500 or less.

[0033] (12) The converter of the present disclosure is The reactor according to any one of (1) to (11) above is included.

[0034] The converter of the present disclosure has low loss because it includes the reactor of the present disclosure.

[0035] (13) The power conversion device of the present disclosure includes: The converter includes the converter described in (12) above.

[0036] The power conversion device of the present disclosure includes the converter of the present disclosure, and therefore has low loss.

[0037] [Details of the embodiment of the present disclosure] Specific examples of the embodiments of the present disclosure will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same objects. Note that the present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0038] [Embodiment 1] [Reactor] A reactor 1a of the first embodiment will be described with reference to Figs. 1 to 3. The reactor 1a includes a coil 2 and a magnetic core 3. The magnetic core 3 includes a first core 3a and a second core 3b. As shown in Fig. 2, the magnetic core 3 is configured by combining the first core 3a and the second core 3b. The magnetic core 3 is formed in a θ shape by a middle core portion 31, a side core portion 33, and an end core portion 35. Fig. 1 is a perspective view of the reactor 1a seen from above. Fig. 2 is a plan view of the reactor 1a seen from above. Fig. 3 is a partial plan view showing an enlarged view of the vicinity of the first end core portion 35a in the reactor 1a shown in Fig. 2.

[0039] The reactor 1a of the first embodiment is characterized in that it satisfies the following requirements (a) and (b). (a) The first core 3a is made of a molded body of a composite material. (b) A protrusion 40 is provided on an outer surface 352a of a first end core portion 35a of a first core 3a.

[0040] The reactor 1a is able to reduce loss in the coil 2 by providing the protrusion 40 on the outer surface 352a of the first end core portion 35a. In particular, by providing the protrusion 40 at a specific location on the outer surface 352a of the first end core portion 35a, it is able to effectively reduce loss in the coil 2. The configuration of the reactor 1a will be described in detail below.

[0041] <Coil> As shown in Figs. 1 and 2, the coil 2 is disposed in the middle core portion 31 of the magnetic core 3. The coil 2 has a cylindrical shape. The coil 2 has a first end face 2a and a second end face 2b. In this embodiment, the coil 2 is an edgewise coil formed by edgewise winding a rectangular wire.

[0042] The shape of the coil 2 may be a polygonal tube or a cylindrical shape. The polygonal tube means that the contour shape of the end face of the coil 2 is polygonal. The polygonal shape is, for example, a quadrangle, a hexagon, and an octagon. The quadrangle includes a rectangle. The rectangle includes a square. The quadrangle is not limited to a geometric quadrangle, but includes a shape formed by connecting four corners. That is, it also includes a quadrangle with details changed, such as a shape in which the four corners are rounded by chamfering, or a shape in which the four corners are chamfered linearly. This point is also the same for the shape of the protrusion 40 described later. The cylindrical shape means that the contour shape of the end face of the coil 2 is circular. The circular shape includes not only a perfect circle shape but also an ellipse shape. In this embodiment, the shape of the coil 2 is a rectangular tube.

[0043] <Magnetic core> As shown in Figures 1 and 2, the magnetic core 3 has middle core portions 31, side core portions 33, and end core portions 35. In Figures 2 and 3, the boundaries between the middle core portions 31 and the end core portions 35 and the boundaries between the side core portions 33 and the end core portions 35 are indicated by two-dot chain lines. This also applies to Figures 6 to 9 described below. As shown in Figure 2, the magnetic core 3 has a θ-shape in a plan view.

[0044] In the following description, the X-axis direction, the Y-axis direction, and the Z-axis direction are defined as follows. The X-axis direction is a direction along the axis of the coil 2, and is a direction from the first end face 2a to the second end face 2b. The Y-axis direction is a direction in which the middle core portion 31 and the side core portion 33 are arranged in parallel, and is a direction from the middle core portion 31 to the side core portion 33. The Y-axis direction is perpendicular to the X-axis direction. The direction from the middle core portion 31 to the first side core portion 331 is defined as the Y1 direction. The direction from the middle core portion 31 to the second side core portion 332 is defined as the Y2 direction. The Z-axis direction is perpendicular to both the X-axis direction and the Y-axis direction. The Z direction is a direction from bottom to top when the XY plane including the X-axis and the Y-axis is horizontal.

[0045] The magnetic core 3 forms a θ-shaped closed magnetic circuit. When the coil 2 is energized, magnetic flux flows through the magnetic core 3. The magnetic flux generated by the coil 2 flows from the middle core portion 31, through the end core portions 35 and the side core portions 33, and back to the middle core portion 31. The dashed arrows in Fig. 2 indicate the flow of magnetic flux. This also applies to Figs. 6 and 8 described below.

[0046] (Middle core section) The middle core portion 31 is disposed in the coil 2 as shown in FIG. 2. There is one middle core portion 31. The middle core portion 31 extends in the X-axis direction. The direction along the length of the middle core portion 31 coincides with the direction along the axis of the coil 2. The length of the middle core portion 31 is equal to or longer than the length of the coil 2. The length here refers to the distance along the X-axis direction. Both ends of the middle core portion 31 may protrude from both end faces of the coil 2. The protruding portions are also part of the middle core portion 31. The shape of the middle core portion 31 corresponds to the inner shape of the coil 2. In this embodiment, the shape of the middle core portion 31 is substantially rectangular parallelepiped.

[0047] The middle core portion 31 is disposed between the first end core portion 35a and the second end core portion 35b. The first end core portion 35a and the second end core portion 35b will be described later. The middle core portion 31 has a first end 32a and a second end 32b. The first end 32a is connected to the first end core portion 35a. The second end 32b is connected to the second end core portion 35b.

[0048] In this embodiment, the middle core portion 31 has a first middle core portion 31a and a second middle core portion 31b. The first middle core portion 31a and the second middle core portion 31b are arranged in series along the X-axis direction. The boundary between the first middle core portion 31a and the second middle core portion 31b is located inside the coil 2. The first middle core portion 31a includes a first end 32a that is coupled to the first end core portion 35a. The second middle core portion 31b includes a second end 32b that is coupled to the second end core portion 35b. "Coupled" means that they are stuck together and do not separate. The first middle core portion 31a and the first end core portion 35a may be molded integrally. When the first middle core portion 31a and the first end core portion 35a are each separate and independent parts, for example, the first end 32a may be bonded to the first end core portion 35a, or the first middle core portion 31a and the first end core portion 35a may be integrated by being at least partially covered with a resin mold. The second middle core portion 31b and the second end core portion 35b may be molded integrally. When the second middle core portion 31b and the second end core portion 35b are independent separate parts, for example, the second end 32b may be bonded to the second end core portion 35b, or the second middle core portion 31b and the second end core portion 35b may be integrated by being at least partially covered with a resin mold. The resin mold is a molding member formed in a continuous manner so as to cover at least a portion of each of the first core 3a and the second core 3b. In this embodiment, the first middle core portion 31a and the first end core portion 35a are molded integrally. The second middle core portion 31b and the second end core portion 35b are molded integrally.

[0049] The length of each of the first middle core portion 31a and the second middle core portion 31b can be set appropriately. In this embodiment, the length of the first middle core portion 31a is different from the length of the second middle core portion 31b. The first middle core portion 31a may be longer than the second middle core portion 31b. The length of the first middle core portion 31a may be shorter than the second middle core portion 31b. The length of the first middle core portion 31a may be the same as the length of the second middle core portion 31b.

[0050] In this embodiment, the middle core portion 31 has a gap portion 31g. The gap portion 31g is provided between the first middle core portion 31a and the second middle core portion 31b. The middle core portion 31 has the gap portion 31g, so that the inductance can be adjusted. The gap portion 31g is located inside the coil 2. When the gap portion 31g is located inside the coil 2, the leakage magnetic flux from the gap portion 31g is reduced compared to when the gap portion 31g is exposed from the coil 2. Therefore, it is easy to suppress the leakage magnetic flux from the gap portion 31g from interlinking with the coil 2. The loss caused by the leakage magnetic flux from the gap portion 31g can be reduced. The length of the gap portion 31g is appropriately set so as to obtain a predetermined inductance. The length of the gap portion 31g is, for example, 0.1 mm or more and 3 mm or less, 0.3 mm or more and 2.5 mm or less, or further 0.5 mm or more and 2 mm or less. The gap portion 31g may be an air gap. The gap portion 31g may be made of a non-magnetic material such as resin or ceramics. When the middle core portion 31 has the gap portion 31g, the length of the middle core portion 31 is the total length of the first middle core portion 31a, the second middle core portion 31b, and the gap portion 31g. The gap portion 31g may be omitted. When the gap portion 31g is omitted, the first middle core portion 31a and the second middle core portion 31b are in contact with each other, and there is substantially no gap between the first middle core portion 31a and the second middle core portion 31b.

[0051] (Side core part) As shown in FIG. 2, the side core portions 33 are disposed outside the coil 2. The side core portions 33 are disposed in parallel with the middle core portion 31 so as to sandwich the coil 2. The inner surface of the side core portion 33 faces the outer peripheral surface of the coil 2. There are two side core portions 33 in number. The side core portions 33 extend in the X-axis direction. The direction along the length of the side core portions 33 is parallel to the direction along the length of the middle core portion 31. The length of the side core portions 33 is equal to the length of the middle core portion 31.

[0052] The side core portion 33 has a first side core portion 331 and a second side core portion 332. The first side core portion 331 and the second side core portion 332 are arranged at an interval in the Y axis direction. The first side core portion 331 is arranged away from the middle core portion 31 in the Y1 direction. The second side core portion 332 is arranged away from the middle core portion 31 in the Y2 direction. In this embodiment, the first side core portion 331 and the second side core portion 332 are arranged symmetrically with respect to the center line of the middle core portion 31.

[0053] The first side core portion 331 and the second side core portion 332 are disposed between the first end core portion 35a and the second end core portion 35b. The first side core portion 331 and the second side core portion 332 each have a first end 34a and a second end 34b. The first end 34a is connected to the first end core portion 35a. The second end 34b is connected to the second end core portion 35b. The first side core portion 331 and the second side core portion 332 only need to have a length that connects the first end core portion 35a and the second end core portion 35b. The first side core portion 331 and the second side core portion 332 may each have any shape. In this embodiment, the first side core portion 331 and the second side core portion 332 each have a shape of a substantially rectangular parallelepiped. The shape of the first side core portion 331 and the shape of the second side core portion 332 are line-symmetrical with respect to the center line of the middle core portion 31.

[0054] In this embodiment, the side core portion 33 and the first end core portion 35a are integrally molded. The side core portion 33 and the first end core portion 35a may be separate independent parts. In this case, for example, the first end 34a may be bonded to the first end core portion 35a, or the side core portion 33 and the first end core portion 35a may be integrated by at least a part of them being covered with a resin mold. In this embodiment, the side core portion 33 and the second end core portion 35b are separate independent parts. The side core portion 33 and the second end core portion 35b are integrated by a resin mold (not shown). The second end 34b of the side core portion 33 may be bonded to the second end core portion 35b.

[0055] (End core part) As shown in FIG. 2, the end core portions 35 are disposed outside the coil 2. The end core portions 35 are disposed so as to face both end faces of the coil 2. There are two end core portions 35. The end core portions 35 have a first end core portion 35a and a second end core portion 35b. The first end core portion 35a faces the first end face 2a of the coil 2. The second end core portion 35b faces the second end face 2b of the coil 2. The first end core portion 35a and the second end core portion 35b are disposed with an interval in the X-axis direction.

[0056] The first end core portion 35a has an inner side surface 351a and an outer side surface 352a. The second end core portion 35b has an inner side surface 351b and an outer side surface 352b. The inner side surface 351a of the first end core portion 35a and the inner side surface 351b of the second end core portion 35b face each other. The first end 32a of the middle core portion 31 and the first ends 34a of the first side core portion 331 and the second side core portion 332 are joined to the inner side surface 351a of the first end core portion 35a. The outer side surface 352a of the first end core portion 35a faces in the opposite direction to the inner side surface 351a. In other words, the outer side surface 352a faces in the direction away from the first end 32a and the first end 34a. The second end 32b of the middle core portion 31 and the second ends 34b of the first side core portion 331 and the second side core portion 332 are joined to the inner side surface 351b of the second end core portion 35b. The outer side surface 352b of the second end core portion 35b faces the opposite side to the inner side surface 351b. In other words, the outer side surface 352b faces in a direction away from the second end 32b and the second end 34b.

[0057] <Protrusion> In this embodiment, the first end core portion 35a has a protrusion 40. The protrusion 40 is provided on an outer side surface 352a of the first end core portion 35a. The protrusion 40 protrudes in a direction away from the inner side surface 351a. As shown in FIG. 1, the protrusion 40 extends in the Z-axis direction from the upper edge to the lower edge of the outer side surface 352a. In other words, the protrusion 40 is provided over the entire height of the first end core portion 35a.

[0058] In this embodiment, as shown in FIG. 2, the number of the protruding portions 40 is two. The protruding portions 40 include a first protruding portion 41 and a second protruding portion 42. The first protruding portion 41 is provided on the outer surface 352a at a position corresponding to between the middle core portion 31 and the first side core portion 331. The position on the outer surface 352a corresponding to between the middle core portion 31 and the first side core portion 331 refers to a region sandwiched between a virtual line extending in the X-axis direction from the outer peripheral surface at the first end 32a of the middle core portion 31 and a virtual line extending in the X-axis direction from the inner surface at the first end 34a of the first side core portion 331 in a plan view. The first protruding portion 41 is located within this region. Hereinafter, this region is referred to as a first outer region. The second protruding portion 42 is provided on the outer surface 352a at a position corresponding to between the middle core portion 31 and the second side core portion 332. The portion of the outer surface 352a corresponding to the area between the middle core portion 31 and the second side core portion 332 refers to a region between an imaginary line extending in the X-axis direction from the outer circumferential surface at the first end 32a of the middle core portion 31 and an imaginary line extending in the X-axis direction from the inner surface at the first end 34a of the second side core portion 332 in a plan view. The second protruding portion 42 is located within this region. Hereinafter, this region will be referred to as a second outer region. In this embodiment, the first protruding portion 41 and the second protruding portion 42 are arranged symmetrically with respect to the center line of the middle core portion 31.

[0059] The first end core portion 35a has the protruding portion 40, which makes it possible to suppress leakage magnetic flux from the first end core portion 35a to the coil 2. Since the leakage magnetic flux from the first end core portion 35a to the coil 2 is reduced, it is possible to reduce loss in the coil 2. In particular, when the first protruding portion 41 and the second protruding portion 42 are provided at specific locations on the outer surface 352a of the first end core portion 35a, leakage magnetic flux from the first end core portion 35a to the coil 2 can be effectively suppressed, so that loss in the coil 2 can be effectively reduced.

[0060] <Protruding part material> The protruding portion 40 is made of a soft magnetic material. The protruding portion 40 may be molded integrally with the first end core portion 35a, or may be a separate part independent of the first end core portion 35a. When the protruding portion 40 and the first end core portion 35a are molded integrally, the protruding portion 40 and the first end core portion 35a are made of the same material. When the protruding portion 40 and the first end core portion 35a are separate parts independent of each other, the material of the protruding portion 40 may be, for example, a composite material molded body, a powder compact, or a plate of a soft magnetic metal. The soft magnetic metal is, for example, iron. When the protruding portion 40 and the first end core portion 35a are separate parts independent of each other, the protruding portion 40 may be bonded to the outer surface 352a of the first end core portion 35a, or may be integrated by resin molding. In this embodiment, the protruding portion 40 is molded integrally with the first end core portion 35a.

[0061] <Shape of protrusion> The shape of the protrusion 40 may be any shape. The shape of the protrusion 40 here refers to the shape in a planar view. The shape of the protrusion 40 is, for example, a polygonal shape or a circular arc shape. The polygonal shape is, for example, a triangular shape, a quadrangular shape, a pentagonal shape, and a hexagonal shape. The quadrangular shape includes, for example, a rectangular shape and a trapezoidal shape. The rectangular shape includes a square shape. The corners of the protrusion 40 may be chamfered. The circular arc shape is a shape having a circular arc. The circular arc shape includes, for example, a semicircular shape and a semielliptical shape. The shape of the first protrusion 41 and the shape of the second protrusion 42 may be the same or different. In this embodiment, the shape of each of the first protrusion 41 and the second protrusion 42 is rectangular.

[0062] The length and width of the protruding portion 40 will be described with reference to Fig. 3. Fig. 3 shows a portion including the first end core portion 35a of the first core 3a in the reactor 1a shown in Fig. 2.

[0063] <Length of protrusion> The length of the first protruding portion 41 and the length of the second protruding portion 42 are, for example, 0.05 times or more and 0.5 times or less than the length of the first end core portion 35a. That is, the ratio of the length L40 of the protruding portion 40 to the length L35 of the first end core portion 35a is 0.05 times or more and 0.5 or less. The ratio of the length L40 to the length L35 is expressed as L40 / L35. The length here refers to the distance along the X-axis direction. The length L35 of the first end core portion 35a corresponds to the distance from the inner side surface 351a to the outer side surface 352a at the portion where the first end 32a of the middle core portion 31 is joined. The length L40 of the protruding portion 40 corresponds to the distance from a virtual plane extending in the Y-axis direction from the outer side surface 352a at the portion where the first end 32a of the middle core portion 31 is joined to the tip of the protruding portion 40. The length L40 is equal to the difference between the distance from the inner surface 351a to the tip of the protrusion 40 and the length L35 of the first end core portion 35a.

[0064] When the length L40 is 0.05 times or more the length L35, i.e., the ratio L40 / L35 is 0.05 or more, leakage flux from the first end core portion 35a to the coil 2 can be effectively suppressed. From the viewpoint of suppressing leakage flux, the ratio L40 / L35 may be further 0.1 or more, or 0.2 or more. When the length L40 is 0.5 times or less the length L35, i.e., the ratio L40 / L35 is 0.5 or less, an increase in the volume of the first end core portion 35a can be suppressed. The ratio L40 / L35 may be, for example, 0.1 to 0.5, or 0.2 to 0.5.

[0065] <Width of protrusion> The width of the first protruding portion 41 is, for example, 0.2 to 1.0 times the interval D33 between the middle core portion 31 and the first side core portion 331. The width of the second protruding portion 42 is, for example, 0.2 to 1.0 times the interval between the middle core portion 31 and the second side core portion 332. That is, the ratio of the width W40 of the protruding portion 40 to the interval D33 between the middle core portion 31 and the side core portion 33 is 0.2 to 1.0. The ratio of the width W40 to the interval D33 is expressed as W40 / D33. The interval D33 refers to the interval between the outer peripheral surface of the middle core portion 31 and the inner surface of the side core portion 33. The interval D33 is the interval between the first end 32a of the middle core portion 31 and the first end 34a of the side core portion 33. The interval D33 is equal to the width of each of the first outer region and the second outer region on the outer surface 352a described above. The width here refers to the distance along the Y-axis direction. The width W40 of the protrusion 40 is the distance along the Y-axis direction. The width W40 corresponds to the maximum distance between the side surface of the protrusion 40 facing the Y1 direction and the side surface facing the Y2 direction. When the protrusion 40 is sandwiched between two lines parallel to the X-axis, the width W40 is equal to the distance between the two lines.

[0066] When the width W40 is 0.2 times or more the interval D33, i.e., the ratio W40 / D33 is 0.2 or more, leakage flux from the first end core portion 35a to the coil 2 can be effectively suppressed. From the viewpoint of suppressing leakage flux, the ratio W40 / D33 may be 0.3 or more, or 0.4 or more. When the width W40 is 1.0 times or less the interval D33, i.e., the ratio W40 / D33 is 1.0 or less, an increase in the volume of the first end core portion 35a can be suppressed. The ratio W40 / D33 may be, for example, 0.3 to 1.0, or 0.4 to 1.0. An example of the ratio W40 / D33 in FIG. 3 is 1.0.

[0067] As shown in FIG. 4 and FIG. 5, the protrusion 40 may be provided in a part of the height of the first end core portion 35a. For example, as in the first modification shown in FIG. 4, the protrusion 40 may be provided in a plurality of parts in the Z-axis direction. In the first modification, the protrusion 40 is provided in a part close to the upper edge and a part close to the lower edge of the outer side surface 352a. For example, as in the second modification shown in FIG. 5, the protrusion 40 may be provided only in the center of the outer side surface 352a. When the protrusion 40 is provided in a part of the height of the first end core portion 35a, the protrusion 40 is provided in a range of, for example, 1 / 2 or more of the height of the first end core portion 35a. In the first modification shown in FIG. 4, the part close to the upper edge of the outer side surface 352a is a 1 / 4 region from the upper edge of the outer side surface 352a divided into 4 equal parts in the Z-axis direction. The part close to the lower edge of the outer side surface 352a is a 1 / 4 region from the lower edge of the outer side surface 352a divided into 4 equal parts in the Z-axis direction. 5, the central portion of the outer side surface 352a is the central half of the region obtained by dividing the outer side surface 352a into four equal parts in the Z-axis direction. The volume of the protruding portion 40 in the first modification is the same as the volume of the protruding portion 40 in the second modification.

[0068] (First core, second core) 2, the magnetic core 3 is composed of a first core 3a and a second core 3b. In this embodiment, the first core 3a has an E-shape, and the second core 3b has a T-shape. In other words, the magnetic core 3 is an ET type composed of the E-shaped first core 3a and the T-shaped second core 3b.

[0069] (First Core) The first core 3a includes a first end core portion 35a and at least a part of the side core portion 33. In this embodiment, the first core 3a has a first end core portion 35a, a first middle core portion 31a, a first side core portion 331, and a second side core portion 332. That is, the first core 3a has the entire side core portion 33. The first middle core portion 31a, the first end core portion 35a, the first side core portion 331, and the second side core portion 332 are integrally molded. Since the first core 3a is an integrally molded product, each core portion constituting the first core 3a is made of the same material. That is, each core portion constituting the first core 3a has substantially the same magnetic properties. The shape of the first core 3a is E-shaped in a plan view.

[0070] (Second core) The second core 3b includes a second end core portion 35b and the remaining portion of the side core portion 33. In this embodiment, the second core 3b has a second end core portion 35b and a second middle core portion 31b. The second end core portion 35b and the second middle core portion 31b are integrally molded. Since the second core 3b is an integrally molded product, the core portions constituting the second core 3b are made of the same material. That is, the magnetic properties of the core portions constituting the second core 3b are substantially the same. The shape of the second core 3b is T-shaped in a plan view.

[0071] At least one of the first core 3a and the second core 3b includes at least a part of the middle core portion 31. The first core 3a may have the entire middle core portion 31. When the first core 3a has the entire middle core portion 31, the second core 3b has only the second end core portion 35b. In this case, the shape of the second core 3b is I-shaped in plan view. The second core 3b may have the entire middle core portion 31. When the second core 3b has the entire middle core portion 31, the first core 3a is composed of a first end core portion 35a, a first side core portion 331, and a second side core portion 332. In this case, the shape of the first core 3a is U-shaped in plan view.

[0072] The side core portion 33 may be divided in the X-axis direction. In this case, the first side core portion 331 and the second side core portion 332 each have a first portion including the first end 34a and a second portion including the second end 34b. The first core 3a may be configured to have the first portions of the first side core portion 331 and the second side core portion 332, and the second core 3b may be configured to have the second portions of the first side core portion 331 and the second side core portion 332. In this case, each of the first core 3a and the second core 3b has an E-shape in a plan view.

[0073] <First core - second relative permeability> The relative permeability of the first core 3a is lower than that of the second core 3b. That is, in the magnetic core 3, the relative permeability of the side core portion 33 is lower than that of the second end core portion 35b. The relative permeability of each of the first core 3a and the second core 3b is appropriately set so as to obtain a predetermined inductance while satisfying the above relationship. The relative permeability of the first core 3a is, for example, 5 or more and 50 or less. The relative permeability of the second core 3b is, for example, 50 or more and 500 or less. If the relative permeability of the first core 3a is in the range of 5 or more and 50 or less and the relative permeability of the second core 3b is in the range of 50 or more and 500 or less, a predetermined inductance is easily obtained. The relative permeability of the first core 3a may be 10 or more and 45 or less, or further 15 or more and 40 or less. The relative permeability of the second core 3b may be 100 or more and 450 or less, or further 150 or more and 400 or less. The difference between the relative permeability of the first core 3a and the relative permeability of the second core 3b is, for example, not less than 50. The difference between the relative permeability of the first core 3a and the relative permeability of the second core 3b may be not less than 50 and not more than 450, or further not less than 100 and not more than 400.

[0074] The relative permeability can be calculated as follows: A ring-shaped measurement sample is cut out from each of the first core 3a and the second core 3b. Each measurement sample is wound with 300 turns on the primary side and 20 turns on the secondary side. The BH initial magnetization curve is measured in the range of H=0 (Oe) to 100 (Oe), and the maximum value of B / H of this BH initial magnetization curve is calculated. This maximum value is the relative permeability. The magnetization curve referred to here is the so-called DC magnetization curve.

[0075] <Materials of the first and second cores> The first core 3a and the second core 3b are each composed of a molded body of a soft magnetic material. The molded body is, for example, a powder compact or a composite material compact. The first core 3a and the second core 3b are composed of molded bodies of different materials. The different materials include not only the case where the materials of the individual components are different in each molded body constituting the first core 3a and the second core 3b, but also the case where the materials of the individual components are the same but the contents of the components are different. For example, even if the first core 3a and the second core 3b are composed of a powder compact, if at least one of the material and the content of the soft magnetic powder constituting the powder compact is different, they are different materials. Also, even if the first core 3a and the second core 3b are composed of a composite material compact, if at least one of the material and the content of the soft magnetic powder constituting the composite material is different, they are different materials.

[0076] The powder compact is formed by compression molding raw material powder containing soft magnetic powder. The powder compact contains a larger amount of soft magnetic powder than the compact of the composite material. Therefore, the powder compact has higher magnetic properties than the compact of the composite material. The magnetic properties are, for example, relative permeability and saturation magnetic flux density. The powder compact may contain, for example, at least one of a binder resin and a molding aid. The content of the soft magnetic powder in the powder compact is, for example, 85% by volume or more and 99.99% by volume or less, when the powder compact is 100% by volume.

[0077] The composite material compact is formed by dispersing soft magnetic powder in resin. The composite material compact is obtained by filling a mold with a fluid material in which soft magnetic powder is dispersed in unsolidified resin, and solidifying the resin. The content of the soft magnetic powder in the composite material compact can be easily adjusted. Therefore, the magnetic properties of the composite material compact can be easily adjusted. The content of the soft magnetic powder in the composite material compact is, for example, 20% by volume or more and 80% by volume or less, when the composite material compact is 100% by volume.

[0078] The particles constituting the soft magnetic powder are at least one selected from the group consisting of soft magnetic metal particles, coated particles having an insulating coating on the outer periphery of soft magnetic metal particles, and soft magnetic nonmetal particles. The soft magnetic metal is, for example, pure iron or an iron-based alloy. The iron-based alloy is, for example, an Fe (iron)-Si (silicon) alloy or an Fe-Ni (nickel) alloy. The insulating coating is, for example, a phosphate. The soft magnetic nonmetal is, for example, a ferrite.

[0079] In this embodiment, the first core 3a is made of a composite material molded body. The second core 3b is made of a powder compact. The first core 3a is made of a composite material molded body and the second core 3b is made of a powder compact, so that the magnetic properties of the entire magnetic core 3 can be adjusted. In addition, when the first core 3a is made of a composite material molded body, the relative magnetic permeability of the first core 3a is likely to be 5 or more and 50 or less. When the second core 3b is made of a powder compact, the relative magnetic permeability of the second core 3b is likely to be 100 or more and 500 or less.

[0080] [Embodiment 2] A reactor 1b of the second embodiment will be described with reference to Fig. 6 and Fig. 7. The reactor 1b of the second embodiment differs from the reactor 1a of the first embodiment in that the second gap between the side core portion 33 and the coil 2 at the second end 34b is larger than the first gap at the first end 34a. The following description will focus on the differences from the first embodiment. Configurations similar to those of the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0081] In the reactor 1b of the second embodiment, the first end core portion 35a has the protruding portion 40, and satisfies the following requirements (c) and (d). (c) The relative permeability of the first core 3a is lower than the relative permeability of the second core 3b. (d) As shown in FIG. 7, the second distance D2 is larger than the first distance D1, and the ratio D1 / D2 of the first distance D1 to the second distance D2 is equal to or greater than 0.32 and equal to or less than 0.70.

[0082] In the reactor 1b, the second distance D2 is larger than the first distance D1, thereby enabling further reduction in the loss in the coil 2. In particular, the ratio D1 / D2 of the first distance D1 to the second distance D2 is equal to or greater than 0.32 and equal to or less than 0.70, thereby enabling effective reduction in the loss in the coil 2 while suppressing a decrease in inductance.

[0083] <Spacing between side core and coil> In this embodiment, the interval between the first side core portion 331 and the coil 2 and the interval between the second side core portion 332 and the coil 2 are not constant along the X-axis direction. In other words, the interval between the side core portion 33 and the coil 2 is not constant along the entire length of the side core portion 33. The interval between the side core portion 33 and the coil 2 increases from the first end 34a toward the second end 34b. The interval between the side core portion 33 and the coil 2 refers to the interval between the inner surface of the side core portion 33 and the outer circumferential surface of the coil 2.

[0084] The interval between the side core portion 33 and the coil 2 will be described in detail with reference to FIG. 7. FIG. 7 shows only one half of the reactor 1b shown in FIG. 6, which is divided into two by the center line of the middle core portion 31, including the first side core portion 331. Here, the interval between the first side core portion 331 and the coil 2 will be described with reference to FIG. 7, but the interval between the second side core portion 332 and the coil 2 is similar. The interval between the first side core portion 331 and the coil 2 is larger in the second interval D2 at the second end 34b than in the first interval D1 at the first end 34a. The first interval D1 refers to the interval between the inner surface located at the first end 34a among the inner surfaces of the first side core portion 331 and a virtual surface extending the outer circumferential surface of the coil 2. When the corner between the end face of the first end 34a and the inner surface is chamfered, it is considered that there is no chamfering. In other words, the interval between the corner between the extended surface of the end face of the first end 34a and the extended surface of the inner surface and the virtual surface is considered to be the first interval D1. The second distance D2 refers to the distance between the inner surface located at the second end 34b among the inner surfaces of the first side core portion 331 and an imaginary plane extending from the outer circumferential surface of the coil 2. When the corner between the end face of the second end 34b and the inner surface is chamfered, it is considered that there is no chamfering. In other words, the distance between the corner between the extended surface of the end face of the second end 34b and the extended surface of the inner surface and the imaginary plane is considered to be the second distance D2.

[0085] The ratio of the first interval D1 to the second interval D2 is 0.32 or more and 0.70 or less. The ratio of the first interval D1 to the second interval D2 is expressed as D1 / D2. The smaller the ratio D1 / D2, the larger the second interval D2. The larger the second interval D2, the larger the interval between the side core portion 33 and the coil 2 in the region near the second end 34b. Therefore, it is possible to suppress the leakage flux that takes a shortcut from the side core portion 33 toward the second end core portion 35b in the region near the second end 34b from interlinking with the coil 2. Since the leakage flux to the coil 2 is reduced, the loss of the coil 2 can be reduced. Since the ratio D1 / D2 is 0.70 or less, the leakage flux to the coil 2 is sufficiently suppressed, so that the loss of the coil 2 can be effectively reduced. If the ratio D1 / D2 is too small, that is, if the second interval D2 is too large, there is a risk that the inductance will decrease, and it may be difficult to obtain a predetermined inductance. When the ratio D1 / D2 is 0.32 or more, it is easy to suppress a decrease in inductance. The ratio D1 / D2 may be further set to 0.35 or more and 0.70 or less, or 0.40 or more and 0.60 or less.

[0086] In Figure 6, the distance D33 (see Figure 3) between the above-mentioned middle core portion 31 and the first side core portion 331 is the distance between the outer peripheral surface at the first end 32a of the middle core portion 31 and the inner surface at the first end 34a of the side core portion 33.

[0087] <Side core shape> The side core portion 33 has a shape in which the width of the side core portion 33 narrows from the first end 34a to the second end 34b. The width of the second end 34b of the side core portion 33 may be narrower than the width of the first end 34a. The side core portion 33 may have a narrower width at least in a portion between the first end 34a and the second end 34b, and may have a constant width in a portion between the first end 34a and the second end 34b. The width of the side core portion 33 is the dimension of the side core portion 33 in the Y-axis direction. In this embodiment, the shape of the first side core portion 331 and the shape of the second side core portion 332 are symmetrical with respect to the center line of the middle core portion 31.

[0088] The shape of the side core portion 33 in this embodiment will be described in detail with reference to FIG. 7. Here, the shape of the first side core portion 331 will be described. The first side core portion 331 has a tapered shape. The tapered shape refers to a shape having a portion whose width continuously narrows from the first end 34a to the second end 34b. In this embodiment, the first side core portion 331 is formed in a tapered shape over the entire length. The inner surface of the first side core portion 331 has an inclined surface 33t inclined with respect to the outer circumferential surface of the coil 2. The inclined surface 33t inclines from the first end 34a to the second end 34b so as to move away from the outer circumferential surface of the coil 2. The angle of the inclined surface 33t with respect to the outer circumferential surface of the coil 2 is appropriately set so that the ratio of the first interval D1 to the second interval D2 satisfies a predetermined range. The angle of the inclined surface 33t refers to the angle formed by the inclined surface 33t and the outer circumferential surface of the coil 2. The outer circumferential surface of the coil 2 is parallel to the X-axis. The angle of the inclined surface 33t can be appropriately set depending on the length of the first side core portion 331. The angle of the inclined surface 33t is, for example, not less than 1° and less than 5°, and further not less than 2° and not more than 4°.

[0089] In Figure 8, the distance D33 (see Figure 3) between the above-mentioned middle core portion 31 and the first side core portion 331 is the distance between the outer peripheral surface at the first end 32a of the middle core portion 31 and the inner surface at the first end 34a of the side core portion 33.

[0090] [Variations] A modified example of the reactor 1b of the second embodiment will be described with reference to Figures 8 and 9. In the modified reactor 1b shown in Figures 8 and 9, the side core portion 33 has a stepped shape.

[0091] The shape of the side core portion 33 in the modified example will be described in detail with reference to FIG. 9. Here, the shape of the first side core portion 331 will be described. The side core portion 33 has a stepped shape. The stepped shape refers to a shape having a portion whose width gradually narrows from the first end 34a to the second end 34b. The inner surface of the first side core portion 331 has a step portion 33s. In the modified example, the step portion 33s is located at the center of the length of the first side core portion 331. The first side core portion 331 is divided into two regions by one step portion 33s. The region from the first end 34a to the step portion 33s is the first region 341. The region from the step portion 33s to the second end 34b is the second region 342. The width of the second region 342 is narrower than the width of the first region 341. The inner side surface of the first region 341 and the inner side surface of the second region 342 are each parallel to the outer circumferential surface of the coil 2. The interval between the inner surface of the second region 342 and the outer peripheral surface of the coil 2 is larger than the interval between the inner surface of the first region 341 and the outer peripheral surface of the coil 2. The width of the step 33s is appropriately set so that the ratio of the first interval D1 to the second interval D2 satisfies a predetermined range. The width of the step 33s corresponds to the distance along the Y-axis direction of the step 33s. The width of the step 33s is equal to the difference between the distance from the outer peripheral surface of the coil 2 to the inner surface of the second region 342 and the distance from the outer peripheral surface of the coil 2 to the inner surface of the first region 341. In other words, the width of the step 33s is expressed as D2-D1. The width of the step 33s is, for example, 1 mm or more and less than 5 mm, and further 1.25 mm or more and 4 mm or less.

[0092] In the modified example, the number of step portions 33s is one, but there may be multiple step portions 33s. When the number of step portions 33s is n, the number of regions constituting the side core portion 33 is n+1. The n+1th region is closer to the second end 34b than the nth region, and the width of the n+1th region is narrower than the width of the nth region. The width gradually narrows from the first region toward the n+1th region.

[0093] The shape of the side core portion 33 may be a combination of a tapered shape and a stepped shape. Modified examples of the shape of the side core portion 33 include the following shapes. (1) In FIG. 9, first region 341 may have a tapered shape, and second region 342 may have no step portion 33s relative to first region 341 and may have a constant width. (2) In FIG. 9, first region 341 may be tapered, and second region 342 may have step 33s with respect to first region 341 and may have a constant width. (3) In FIG. 9, first region 341 has a shape with a constant width, and second region 342 does not have step portion 33s with respect to first region 341, and may have a tapered shape. (4) In FIG. 9, first region 341 has a shape with a constant width, and second region 342 has step portion 33s with respect to first region 341, and may have a tapered shape.

[0094] [Embodiment 3] [Converter / Power Conversion Device] The reactor of the embodiment can be used in applications that satisfy the following energization conditions. The energization conditions are, for example, a maximum DC current of about 100 A to 1000 A, an average voltage of about 100 V to 1000 V, and an operating frequency of about 5 kHz to 100 kHz. The reactor of the embodiment can be used as a component of a converter mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and as a component of a power conversion device including the converter.

[0095] As shown in Fig. 10, a vehicle 1200 such as a hybrid vehicle or an electric vehicle includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and 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. The motor 1220 drives wheels 1250 during traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 includes an engine 1300 in addition to the motor 1220. Although Fig. 10 shows an inlet as a charging point for the vehicle 1200, a form including a plug may be used.

[0096] 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 about 200V to 300V, to about 400V to 700V when the vehicle 1200 is running, and supplies power to the inverter 1120. During regeneration, the converter 1110 lowers 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. During regeneration, the inverter 1120 converts the AC output from the motor 1220 into DC and outputs it to the converter 1110.

[0097] As shown in FIG. 11, the converter 1110 includes a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115, and converts the input voltage by repeatedly turning the switching elements 1111 on and off. The conversion of the input voltage means stepping up and down the voltage here. The switching elements 1111 include power devices such as field effect transistors and insulated gate bipolar transistors. The reactor 1115 has a function of smoothing the change when the current increases or decreases due to the switching operation by utilizing the properties of a coil that prevents changes in the current flowing through the circuit. The reactor 1115 includes the reactor of the embodiment. By including the reactor of the embodiment, the loss of the power conversion device 1100 and the converter 1110 is small.

[0098] In addition to the converter 1110, the vehicle 1200 includes a power supply converter 1150 connected to the main battery 1210, and an auxiliary power converter 1160 connected to the sub-battery 1230 serving as a power source for the auxiliary devices 1240 and the main battery 1210 to convert the high voltage of the main battery 1210 to a low voltage. The converter 1110 typically performs DC-DC conversion, while the power supply converter 1150 and the auxiliary power converter 1160 perform AC-DC conversion. Some of the power supply converters 1150 perform DC-DC conversion. The reactors of the power supply converter 1150 and the auxiliary power converter 1160 may have the same configuration as the reactor of the embodiment, and may be appropriately changed in size or shape. The reactor of the embodiment may also be used as a converter that converts input power and that only boosts or only lowers the voltage.

[0099] <Test Example 1> The inductance and loss of a reactor having a configuration similar to that of the reactor 1a of the first embodiment were evaluated.

[0100] In Test Example 1, reactors of Sample No. 1-0 to Sample No. 1-7 shown in Table 1 were designed. Sample No. 1-0 to Sample No. 1-7 are models in which the length L40 of each of the first protruding portion 41 and the second protruding portion 42 is changed in the range from 0 mm to 10 mm. Sample No. 1-0, in which the length L40 of the protruding portion 40 is 0 mm, does not have the first protruding portion 41 or the second protruding portion 42. The basic configuration of the designed reactor is shown below.

[0101] (Magnetic core size) Length of magnetic core 3 L: 80mm Magnetic core 3 width W: 65mm Height of magnetic core 3: 25mm 1, the length L is the dimension of the magnetic core 3 in the X-axis direction. The width W is the dimension of the magnetic core 3 in the Y-axis direction. The height H is the dimension of the magnetic core 3 in the Z-axis direction. (Size of each core) Length of middle core 31: 53.2mm Width of middle core 31: 25mm Length of each of the first side core portion 331 and the second side core portion 332: 53.2 mm Width of each of the first side core portion 331 and the second side core portion 332: 9 mm Length of each of the first end core portion 35a and the second end core portion 35b: 13.4 mm Width of each of the first end core portion 35a and the second end core portion 35b: 65 mm Length of gap 31g: 2mm Distance between the middle core portion 31 and the first side core portion 331: 11 mm Distance between the middle core portion 31 and the second side core portion 332: 11 mm The length of each core portion is the dimension in the X-axis direction. The width of each core portion is the dimension in the Y-axis direction. The height of each core portion, i.e., the dimension in the Z-axis direction, is 25 mm.

[0102] Relative permeability of first core 3a: 20 Relative permeability of second core 3b: 200

[0103] Table 1 shows the length L40 of the protruding portion 40, the length L35 of the first end core portion 35a, and the ratio of length L40 to length L35 (L40 / L35) in Sample No. 1-0 to Sample No. 1-7. The width W40 of each of the first protruding portion 41 and the second protruding portion 42 is 11 mm. The distance D33 between the middle core portion 31 and the side core portion 33 is 11 mm. The ratio of width W40 to distance D33 (W40 / D33) is 1.

[0104] The inductance and loss of each sample reactor were analyzed using JMAG-Designer21.0, a commercially available electromagnetic field analysis software made by JSOL Corporation, to perform a magnetic field transient response analysis.

[0105] (Inductance Analysis) The inductance was analyzed when currents of 0A to 400A were passed through the coil. The maximum inductance value was obtained from the amount of magnetic flux linkage in the coil when the current value was 0A. The inductance of each sample is shown in Table 1. The inductance shown in Table 1 is shown as a ratio, with the inductance of sample No. 1-0 as the reference (100%).

[0106] (Loss Analysis) Losses were analyzed when a DC current of 0A, an input voltage of 300V, an output voltage of 600V, and a frequency of 20kHz were applied to the coil. Coil losses were determined from the magnetic flux density distribution and current density distribution. The coil losses for each sample are shown in Table 1. The coil losses are shown as a percentage with the coil loss of sample No. 1-0 taken as the reference (100%). The coil loss reduction rate A for each sample is also shown in Table 1. Coil loss reduction rate A is the coil loss for each sample minus the coil loss of sample No. 1-0. If coil loss reduction rate A is 1% or more, it is considered that the effect of reducing coil loss has been achieved.

[0107] (Evaluation of volume increase rate) The volume of the magnetic core was measured for each sample reactor. Here, the volume of the first core in each sample was obtained. The increase rate of the volume of the first core in each sample No. 1-1 to No. 1-7 relative to the volume of the first core in sample No. 1-0 was calculated. The volume increase rate was obtained as follows. The increase in the volume of the first core in each sample relative to the volume of the first core in sample No. 1-0 was calculated. The volume increase rate was calculated by subtracting the volume of the first core in sample No. 1-0 from the volume of the first core in each sample. The volume increase rate is expressed as a percentage of the volume increase amount Va of the first core in each sample relative to the volume V0 of the first core in sample No. 1-0. In other words, the volume increase rate is expressed as [Va / V0] x 100. The volume increase rate B of each sample is shown in Table 1.

[0108] (Efficiency evaluation) For each sample reactor, the efficiency of coil loss reduction relative to the increase in the volume of the first core was evaluated. Efficiency is expressed as a percentage of the coil loss reduction rate A relative to the volume increase rate B. Efficiency is expressed as [A / B] x 100. The efficiency of each sample is shown in Table 1. When this efficiency value is 75% or higher, it can be said that the efficiency of coil loss reduction is high.

[0109] [Table 1]

[0110] As shown in Table 1, the coil loss reduction rate A of sample No. 1-1 to sample No. 1-7 is 1% or more. In other words, the coil loss of sample No. 1-1 to sample No. 1-7 is reduced by 1% or more compared to the coil loss of sample No. 1-0. This shows that the protrusions of sample No. 1-1 to sample No. 1-7 have the effect of reducing coil loss. Furthermore, the inductance of sample No. 1-1 to sample No. 1-7 is not reduced compared to the inductance of sample No. 1-0. It can be said that the effect of the protrusions on inductance is small.

[0111] In Sample No. 1-1 to Sample No. 1-7, the ratio of the length L40 of the protruding portion to the length L35 of the first end core portion, i.e., L40 / L35, is 0.05 or more. From the results of Sample No. 1-1 to Sample No. 1-7, it can be seen that the effect of reducing coil loss is more easily obtained as the length L40 increases, i.e., the ratio of the length L40 to the length L35 increases. However, if the ratio of the length L40 to the length L35 becomes too large, the volume of the first core increases and the volume increase rate B increases. In addition, if the volume increase rate B increases, the efficiency tends to decrease. Sample No. 1-1 to Sample No. 1-4, in which L40 / L35 is 0.5 or less, have an efficiency of 75% or more and are highly efficient. The ratio of the length L40 to the length L35 at which the efficiency of reducing coil loss is high and the effect of reducing coil loss is obtained is considered to be 0.05 or more and 0.5 or less.

[0112] <Test Example 2> In Test Example 2, reactors of Sample No. 2-0 to Sample No. 2-7 shown in Table 2 were designed. Sample No. 2-0 to Sample No. 2-7 are models in which the width W40 of each of the first protruding portion 41 and the second protruding portion 42 is changed in the range from 0 mm to 10 mm. Sample No. 2-0, in which the width W40 of the protruding portion 40 is 0 mm, does not have the first protruding portion 41 or the second protruding portion 42. Sample No. 2-0 has the same configuration as Sample No. 1-0 in Test Example 1. The basic configuration of the designed reactor is the same as that of Test Example 1.

[0113] Table 2 shows the width W40 of the protruding portion 40, the distance D33 between the middle core portion 31 and the side core portion 33, and the ratio (W40 / D33) of the width W40 to the distance D33 in Sample No. 2-0 to Sample No. 2-7. The length L40 of each of the first protruding portion 41 and the second protruding portion 42 is 5 mm. The length L35 of the first end core portion 35a is 13.4 mm. The ratio (L40 / L35) of the length L40 to the length L35 is 0.37.

[0114] The inductance and loss of the reactor of each sample were analyzed. The inductance and coil loss of each sample were determined in the same manner as in Test Example 1. The inductance and coil loss of each sample are shown in Table 2. The inductance shown in Table 2 is shown as a ratio with the inductance of sample No. 2-0 as the reference (100%). The coil loss shown in Table 2 is shown as a ratio with the coil loss of sample No. 2-0 as the reference (100%). The coil loss reduction rate A of each sample is also shown in Table 1. The coil loss reduction rate A is calculated by subtracting the coil loss of sample No. 2-0 from the coil loss of each sample.

[0115] Furthermore, the volume increase rate and efficiency of each sample were determined in the same manner as in Test Example 1. The volume increase rate B and efficiency of each sample are shown in Table 2.

[0116] [Table 2]

[0117] As shown in Table 2, the coil loss reduction rate A of sample No. 2-2 to sample No. 2-7 is 1% or more. Therefore, it can be seen that the protrusions of sample No. 2-2 to sample No. 2-7 have the effect of reducing coil loss. Furthermore, the inductance of sample No. 2-2 to sample No. 2-7 is not reduced compared to the inductance of sample No. 2-0. It can be said that the effect of the protrusions on inductance is small.

[0118] In samples No. 2-2 to No. 2-7, the ratio of the width W40 of the protruding portion to the spacing D33 between the middle core portion and the side core portion, i.e., W40 / D33, is 0.2 or more. From the results of samples No. 2-1 to No. 2-7, it can be seen that the larger the width W40 is, i.e., the larger the ratio of the width L40 to the spacing D33 is, the easier it is to obtain the effect of reducing coil loss. Furthermore, samples No. 2-2 to No. 2-7, in which W40 / D33 is 1.0 or less, have an efficiency of 75% or more, and thus have high efficiency. It is considered that the ratio of width 40 to spacing 33, which has high efficiency in reducing coil loss and provides the effect of reducing coil loss, is 0.2 or more and 1.0 or less.

[0119] <Test Example 3> The inductance and loss of the reactors of Modification 1 and Modification 2 were evaluated.

[0120] In Test Example 3, reactors of Sample No. 3-1 and Sample No. 3-2 shown in Table 3 were designed. Both Sample No. 3-1 and Sample No. 3-2 have a first protruding portion 41 and a second protruding portion 42. The basic configuration of the designed reactor is the same as that of Test Example 1.

[0121] Sample No. 3-1 has the same configuration as Modification Example 1. In Sample No. 3-1, the first protrusion 41 and the second protrusion 42 are each divided into two in the Z-axis direction. In Sample No. 3-1, the protrusions are disposed near the upper edge and near the lower edge of the outer surface 352a. The two protrusions aligned in the Z-axis direction are the same size. The height of the two protrusions in the Z-axis direction is 7.5 mm. The total height of the two protrusions is 15 mm.

[0122] Sample No. 3-2 has the same configuration as Modification 2. In Sample No. 3-2, the first protrusion 41 and the second protrusion 42 are each disposed only in the center of the outer side surface 352a. The height of the protrusion in the Z-axis direction is 15 mm.

[0123] The length L40 of each of the first protrusion 41 and the second protrusion 42 in Sample No. 3-1 and Sample No. 3-2 is 5.5 mm. The ratio (L40 / L35) of the length L40 to the length L35 is 0.41. The width W40 of each of the first protrusion 41 and the second protrusion 42 is 11 mm. The ratio (W40 / D33) of the width W40 to the distance D33 is 1. The volume of the protrusion in Sample No. 3-1 is equal to the volume of the protrusion in Sample No. 3-2. In other words, the volume of the first core in Sample No. 3-1 is equal to the volume of the first core in Sample No. 3-2.

[0124] The inductance and loss of the reactor of each sample were analyzed. The inductance and coil loss of each sample were determined in the same manner as in Test Example 1. The inductance and coil loss of each sample are shown in Table 3. The inductance shown in Table 3 is shown as a ratio with the inductance of Sample No. 1-0 of Test Example 1 as the reference (100%). The coil loss shown in Table 3 is shown as a ratio with the coil loss of Sample No. 1-0 as the reference (100%). The coil loss reduction rate A of each sample is also shown in Table 1. The coil loss reduction rate A is the coil loss of each sample minus the coil loss of Sample No. 1-0.

[0125] [Table 3]

[0126] As shown in Table 3, the coil loss reduction rate A of sample No. 3-1 and sample No. 3-2 is 1% or more. Comparing sample No. 3-1 and sample No. 3-2, it is found that the coil loss of sample No. 3-1 is smaller than that of sample No. 3-2. From this result, it is considered that the coil loss can be effectively reduced by arranging the protrusions near the upper edge and near the lower edge of the outer surface of the first end core portion.

[0127] <Test Example 4> The inductance and loss of a reactor having a similar configuration to the reactor 1b of the second embodiment were evaluated.

[0128] In Test Example 4, reactors of Sample No. 4-0 to Sample No. 4-7 shown in Table 4 were designed. All of Sample No. 4-0 to No. 4-7 have a first protruding portion 41 and a second protruding portion 42. Sample No. 4-0 to No. 4-7 are models in which the angle of the inclined surface 33t on the inner surface of the side core portion 33 is changed in the range from 0° to 7°. Sample No. 4-0 has the same configuration as Sample No. 1-4 in Test Example 1. The basic configuration of the designed reactor is the same as that of Test Example 1.

[0129] In Sample No. 4-0 to Sample No. 4-7, the length L40 of each of the first protruding portion 41 and the second protruding portion 42 is 5.5 mm. The ratio of the length L40 to the length L35 (L40 / L35) is 0.41. The width W40 of each of the first protruding portion 41 and the second protruding portion 42 is 11 mm. The ratio of the width W40 to the distance D33 (W40 / D33) is 1.

[0130] Table 4 shows the angles of the inclined surfaces in Samples No. 4-0 to No. 4-7. Table 4 also shows the first interval D1, the second interval D2, and the ratio (D1 / D2) of the first interval D1 to the second interval D2 for each sample. In Sample No. 4-0, in which the angle of the inclined surface 33t is 0°, the interval between the side core portion 33 and the coil 2 is constant over the entire length of the side core portion 33. That is, in Sample No. 4-0, the ratio of the first interval D1 to the second interval D2 is 1. The first interval D1 and the second interval D2 in Sample No. 4-0 are each 2 mm.

[0131] The inductance and loss of the reactor of each sample were analyzed. The inductance and coil loss of each sample were determined in the same manner as in Test Example 1. The inductance and coil loss of each sample are shown in Table 4. The inductance shown in Table 4 is shown as a ratio with the inductance of Sample No. 1-0 of Test Example 1 as the reference (100%). The coil loss shown in Table 4 is shown as a ratio with the coil loss of Sample No. 1-0 as the reference (100%). The coil loss reduction rate A of each sample is also shown in Table 4. The coil loss reduction rate A is calculated by subtracting the coil loss of Sample No. 1-0 from the coil loss of each sample.

[0132] [Table 4]

[0133] As shown in Table 4, the coil loss of Sample No. 4-1 to Sample No. 4-7 is further reduced compared to the coil loss of Sample No. 4-0. In Sample No. 4-1 to Sample No. 4-7, the second distance D2 is larger than the first distance D1, and the ratio of the first distance D1 to the second distance D2 is 0.70 or less. From the results of Sample No. 4-1 to Sample No. 4-7, it can be seen that the larger the second distance D2 is, that is, the smaller the ratio of the first distance D1 to the second distance D2 is, the easier it is to obtain the effect of reducing the coil loss. However, it can be seen that the inductance decreases when the ratio of the first distance D1 to the second distance D2 is smaller. The inductance of Sample No. 4-1 to Sample No. 4-4 is reduced by less than 5% compared to the inductance of Sample No. 1-0. If the reduction in inductance is less than 5%, it can be considered to be approximately the same as that of Sample No. 1-0. In samples No. 4-1 to No. 4-4, the ratio of the first distance D1 to the second distance D2 is 0.32 or more. It is considered that the ratio of the first distance D1 to the second distance D2 that can maintain a good inductance and reduce coil loss is 0.32 or more and 0.70 or less. [Explanation of symbols]

[0134] 1a, 1b Reactor 2 Coil 2a first end face, 2b second end face 3. Magnetic core 3a 1st core, 3b 2nd core 31 Middle Core Division 31a first middle core portion, 31b second middle core portion 31g Gap section 32a first end, 32b second end 33 Side core part 331 first side core portion, 332 second side core portion 33t slope, 33s step 34a first end, 34b second end 341 first area, 342 second area 35 End Core Section 35a first end core portion, 35b second end core portion 351a, 351b inner surface 352a, 352b outer surface 40 Protrusion 41 first protrusion, 42 second protrusion D1 first interval, D2 second interval D33 Spacing L, L40, L35 Length W, W40 width H Height 1100 Power conversion device 1110 converter, 1111 switching element, 1112 drive circuit 1115 Reactor, 1120 Inverter 1150 Converter for power supply device, 1160 Converter for auxiliary power supply 1200 vehicles 1210 Main battery, 1220 Motor, 1230 Sub battery 1240 Auxiliary equipment, 1250 Wheels 1300 Engine

Claims

1. The coil has a cylindrical shape and a magnetic core has a θ shape. the coil has a first end surface and a second end surface; The magnetic core includes a first core and a second core, The first core includes a first end core portion and at least a portion of a side core portion, the second core includes a second end core portion and a remainder of the side core portion, At least one of the first core and the second core includes at least a portion of a middle core portion, the first end core portion is disposed to face the first end surface of the coil, the second end core portion is disposed to face the second end surface of the coil, The middle core portion is disposed within the coil, the side core portion includes a first side core portion and a second side core portion arranged in parallel with the middle core portion so as to sandwich the coil therebetween, The first core is formed of a composite material molded body in which soft magnetic powder is dispersed in a resin, The first end core portion is an inner surface to which first ends of the middle core portion, the first side core portion, and the second side core portion are joined; An outer surface facing away from the inner surface; a protrusion provided on the outer surface, The protrusion includes a first protrusion and a second protrusion, the first protruding portion is provided on the outer surface at a position corresponding to a position between the middle core portion and the first side core portion, The second protruding portion is provided on the outer surface at a position corresponding to a position between the middle core portion and the second side core portion. Reactor.

2. The reactor according to claim 1 , wherein a length of the first protruding portion and a length of the second protruding portion are each 0.05 to 0.5 times a length of the first end core portion.

3. a width of the first protruding portion is 0.2 to 1.0 times the distance between the middle core portion and the first side core portion, The reactor according to claim 1 , wherein a width of the second protruding portion is equal to or greater than 0.2 times and equal to or less than 1.0 times a distance between the middle core portion and the second side core portion.

4. The reactor according to claim 1 , wherein the first core has a relative permeability of 5 or more and 50 or less.

5. The middle core portion has a first middle core portion and a second middle core portion, the first middle core portion is connected to the first end core portion, The reactor according to claim 1 , wherein the second middle core portion is coupled to the second end core portion.

6. The reactor according to claim 5 , wherein the middle core portion has a gap portion between the first middle core portion and the second middle core portion.

7. The first core includes the entire side core portion, the relative permeability of the first core is lower than the relative permeability of the second core, the first side core portion and the second side core portion each have a first end joined to the first end core portion and a second end joined to the second end core portion, a first distance between the first side core portion and the coil and a second distance between the second side core portion and the coil at the second end are larger than a first distance at the first end, The reactor according to claim 1 , wherein a ratio of the first interval to the second interval is equal to or greater than 0.32 and is equal to or less than 0.

70.

8. The reactor according to claim 7 , wherein the first side core portion and the second side core portion each have a tapered shape whose width decreases from the first end toward the second end.

9. The reactor according to claim 7 , wherein each of the first side core portion and the second side core portion has a stepped shape whose width decreases from the first end toward the second end.

10. The reactor according to claim 1 , wherein the second core has a relative permeability of 100 or more and 500 or less.

11. The reactor according to claim 1 , wherein the second core is formed of a powder compact.

12. A reactor according to any one of claims 1 to 11, converter.

13. A converter comprising: Power conversion equipment.

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