Magnetic component

Abstract

The present disclosure addresses the problem of reducing eddy current loss due to leakage flux. A magnetic component (1) comprises a first core (2), a second core (3), and a coil (4). The first core (2) and the second core (3) are formed from a magnetic material and are arranged so as to face each other in a facing direction (D1) and to be in partial contact with each other. The coil (4) is wound around the first core (2). The first core (2) has a shaft (22) around which the coil (4) is wound and which is in contact with the second core (3). The shaft (22) has a thin shaft portion (6). A contact surface (63) that is in contact with the second core (3) in the facing direction (D1) is formed on the thin shaft portion (6). The shape of the thin shaft portion (6) tapers toward the contact surface (63) along the facing direction (D1).

Description

Magnetic Components

[0001] The present disclosure relates generally to magnetic components, and more particularly to magnetic components including a coil and multiple cores.

[0002] Patent Document 1 discloses a transformer having a transformer core formed by a pair of core bodies, in which a primary winding and a secondary winding are mounted in a spatial region including the periphery of a central leg of one of the pair of core bodies.

[0003] In a transformer (magnetic component) including a pair of core bodies (first core and second core), such as the transformer of Patent Document 1, it is desirable to reduce eddy current loss due to leakage magnetic flux.

[0004] JP 2010-267816 A

[0005] The present disclosure has been made in view of the above-mentioned circumstances, and an object of the present disclosure is to provide a magnetic member that can reduce eddy current loss due to leakage magnetic flux.

[0006] A magnetic component according to one aspect of the present disclosure includes a first core, a second core, and a coil. The first core and the second core are formed of a magnetic material and are arranged to face each other in an opposing direction and to be in contact with each other in part. The coil is wound around the first core. The first core has a shaft portion around which the coil is wound and which is in contact with the second core. The shaft portion has a thin shaft portion. The thin shaft portion has a contact surface which is in contact with the second core in the opposing direction. The thin shaft portion has a shape which tapers toward the contact surface along the opposing direction.

[0007] FIG. 1 is a perspective view showing the configuration of a magnetic component according to an embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a plan view showing a thin shaft portion of the magnetic component according to the embodiment. FIG. 4 is a plan view showing a contact surface of the thin shaft portion of the magnetic component according to the embodiment. FIG. 5 is a plan view showing a thin shaft portion of a magnetic component according to a first modification. FIG. 6 is a plan view showing a thin shaft portion of a magnetic component according to a second modification. FIG. 7 is a plan view showing a contact surface of the thin shaft portion of the magnetic component according to the embodiment. FIG. 8 is a plan view showing a first core and a second core of a magnetic component according to a third modification. FIG. 9 is a plan view showing a first core and a second core of a magnetic component according to a fourth modification.

[0008] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Common elements in the embodiments described below are designated by the same reference numerals, and redundant descriptions of the common elements may be omitted. The following embodiments and modifications are merely a portion of various embodiments of the present disclosure. Various modifications of the following embodiments and modifications may be made depending on the design, etc., as long as the object of the present disclosure can be achieved. The configurations of the embodiments and modifications may also be combined as appropriate.

[0009] The drawings described in this disclosure are schematic drawings, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0010] (1) Overview First, an overview of the magnetic component 1 according to this embodiment will be described with reference to FIG. 1 . Hereinafter, as an example, an orthogonal coordinate system having three mutually orthogonal axes, the X-axis, the Y-axis, and the Z-axis, will be defined. In particular, the axis along the opposing direction D1 in which the first core 2 and the second core 3 are aligned will be referred to as the "Z-axis." Furthermore, one axis orthogonal to the Z-axis will be referred to as the "X-axis." The X-axis is the direction in which the pair of shaft portions 22 of the first core 2 are aligned. Furthermore, the axis orthogonal to both the Z-axis and the X-axis will be referred to as the "Y-axis." The X-axis, Y-axis, and Z-axis are all imaginary axes, and the arrows indicating "X," "Y," and "Z" in the drawings are merely shown for the purpose of explanation and do not have any physical substance. Furthermore, these directions are not intended to limit the orientation of the magnetic component 1 during use.

[0011] In addition, "orthogonal (perpendicular)" as used herein does not only refer to a state in which the angle between two elements is strictly 90 degrees, but also includes a state in which two elements intersect within a certain range of difference. In other words, the angle between two elements that are perpendicular to each other falls within a certain range of difference from 90 degrees (for example, 5 degrees or less). In other words, "orthogonal" as used herein includes cases in which the angle between two elements is 85 degrees or more and 95 degrees or less.

[0012] The magnetic component 1 is, for example, an inductor or a transformer used in an electric circuit. In this embodiment, the magnetic component 1 is a transformer.

[0013] As shown in FIG. 1 , the magnetic component 1 includes a first core 2 , a second core 3 , and a coil 4 .

[0014] The coil 4 is wound around the first core 2 .

[0015] The first core 2 and the second core 3 are made of a magnetic material. The first core 2 and the second core 3 face each other in the facing direction D1 and are arranged so that parts of the first core 2 and the second core 3 are in contact with each other. The first core 2 has a shaft portion 22.

[0016] The coil 4 is wound around the shaft portion 22. The shaft portion 22 is in contact with the second core 3. The shaft portion 22 has a thin shaft portion 6.

[0017] A contact surface 63 (see FIG. 3) that comes into contact with the second core in the facing direction D1 is formed on the thin shaft portion 6. The shape of the thin shaft portion 6 tapers toward the contact surface 63 along the facing direction D1.

[0018] In this embodiment, the thin shaft portion 6 becomes thinner as it approaches the contact surface 63. Therefore, in a direction perpendicular to the facing direction D1 (the X-axis direction in the example of FIG. 1), the side surface 64 (see FIG. 3) of the thin shaft portion 6 and the contact surface 63 that comes into contact with the second core 3 are farther from the coil 4 than other parts of the shaft portion 22. This makes it possible to prevent leakage flux that crosses the contact surface 63 from interlinking with the coil 4, thereby reducing eddy current loss.

[0019] Furthermore, according to the magnetic component 1 of this embodiment, the shaft portion has a thin shaft portion that abruptly becomes thinner from the other parts of the shaft portion, creating a step, which makes it possible to suppress a decrease in the strength of the shaft portion 22 compared to a configuration in which the contact surface is separated from the coil.

[0020] (2) Details The detailed configuration of the magnetic component 1 according to this embodiment will be described below with reference to FIGS.

[0021] 1 , the magnetic component 1 of this embodiment has a rectangular frame shape when viewed in a plan view in the Y-axis direction. The magnetic component 1 includes a pair of cores (a first core 2 and a second core 3), a pair of coils 4, and a pair of frame members 5.

[0022] (2.1) Configuration of the Pair of Cores The pair of cores includes a first core 2 and a second core 3. The first core 2 and the second core 3 are formed of a magnetic material such as ferrite. In this embodiment, the first core 2 and the second core 3 face each other in the facing direction D1. In this embodiment, the first core 2 and the second core 3 each have two contact surfaces 63 (see FIG. 2 ). The two contact surfaces 63 of the first core 2 correspond one-to-one to the two contact surfaces 63 of the second core 3. Each of the two contact surfaces 63 of the first core 2 is in surface contact with the corresponding contact surface 63 of the second core 3. In other words, the contact surface 63 of the first core 2 and the contact surface 63 of the second core 3 form gap surfaces between the first core 2 and the second core 3.

[0023] In addition, the first core 2 and the second core 3 of this embodiment have the same shape and are symmetrical in the facing direction D1. More specifically, the first core 2 and the second core 3 of this embodiment are symmetrical in the facing direction D1 with respect to the contact surface 63 (see FIG. 3 ).

[0024] When a current flows through the coil 4 wound around the first core 2 and the second core 3 , a magnetic field is generated, and a magnetic flux passes through the inside of the first core 2 and the second core 3 .

[0025] (2.1.1) First Core In this embodiment, the first core 2 has a U-shape that opens in the negative direction of the Z axis when viewed in a plan view in the Y axis direction. The first core 2 has a base 21 and a pair of shaft portions 22.

[0026] The base 21 has a rectangular parallelepiped shape, and the thickness direction of the base 21 is along the Z axis.

[0027] The pair of shaft portions 22 protrude in the negative direction of the Z axis from both ends of the base portion 21 in the X axis direction. The pair of shaft portions 22 have the same shape. As shown in FIG. 2 , the shaft portion 22 has a first shaft portion 220 and a second shaft portion (thin shaft portion 6).

[0028] The first shaft portion 220 protrudes in the negative direction of the Z axis from the end of the base portion 21 in the X axis direction. The shape of the first shaft portion 220 is a rectangular parallelepiped. In this embodiment, the cross-sectional shape of the first shaft portion 220 along the XY plane is a square with a side length of the third length A3 (see FIG. 3 ).

[0029] The thin shaft portion 6 protrudes from the tip of the first shaft portion 220 in the negative direction of the Z axis. The thin shaft portion 6 is thinner than the other portions of the shaft portion 22. In other words, the thin shaft portion 6 is thinner than the first shaft portion 220. As shown in FIG. 3 , the thin shaft portion 6 has a truncated cone shape that becomes thinner in the negative direction of the Z axis. In this embodiment, when viewed in a plane in a direction perpendicular to the facing direction D1 (e.g., the Y axis direction), the side surfaces 64 of the thin shaft portion 6 (e.g., both ends in the X axis direction) have an arc shape. More specifically, in this embodiment, when viewed in a plane in a direction perpendicular to the facing direction D1, the side surfaces 64 of the thin shaft portion 6 have an arc shape that forms a part of a perfect circle. In other words, the generatrix of the truncated cone-shaped thin shaft portion 6 has an arc shape that forms a part of a perfect circle.

[0030] The thin shaft portion 6 has a first end 61 and a second end 62. The first end 61 and the second end 62 are opposite ends of the thin shaft portion 6 in the opposing direction D1. The first end 61 is the boundary with the first shaft portion 220. The second end 62 is the tip of the thin shaft portion 6. A contact surface 63 is formed at the second end 62. In other words, the second end 62 functions as the contact surface 63.

[0031] In this embodiment, the first length A1, which is the length between the first end 61 and the second end 62 in the facing direction D1, is equal to the second length A2, which is the depth of the recess in the thin shaft portion 6. In other words, the first length A1, which is the length between the first end 61 and the second end 62 in the facing direction D1, is equal to the second length A2, which is the difference between the third length A3, which is the width of the first end 61 in a direction perpendicular to the facing direction D1 (e.g., the X-axis direction), and the fourth length A4, which is the width of the second end 62 in a direction perpendicular to the facing direction D1.

[0032] A pair of contact surfaces 63 of the first core 2 correspond one-to-one to a pair of contact surfaces 63 of the second core 3. The contact surfaces 63 of the first core 2 are in surface contact with the corresponding contact surfaces 63 of the second core 3. In other words, the contact surfaces 63 of the first core 2 and the contact surfaces 63 of the second core 3 form gap surfaces between the first core 2 and the second core 3.

[0033] As shown in FIG. 4 , the contact surface 63 in this embodiment has a perfect circular shape. The diameter of the contact surface 63 in this embodiment is the width of the second end 62 in a direction perpendicular to the facing direction D1, which is the fourth length A4. The area of ​​the contact surface 63 is smaller than the cross-sectional area of ​​the first shaft portion 220 along the XY plane. Furthermore, in this embodiment, the area of ​​the contact surface 63 is an area where the magnetic flux density at the contact surface 63 when a current is flowing through the coil 4 is less than the saturation magnetic flux density. In other words, the area of ​​the contact surface 63 is smaller than the cross-sectional area of ​​the first shaft portion 220 and larger than the area of ​​the contact surface when the magnetic flux density at the contact surface 63 is the saturation magnetic flux density. This makes it possible to suppress the generation of leakage magnetic flux across the contact surface 63, thereby further reducing eddy current loss due to leakage magnetic flux.

[0034] (2.1.2) Second Core As described above, in this embodiment, the first core 2 and the second core 3 are symmetrical in the opposing direction D1. That is, the shape of the second core 3 in this embodiment is U-shaped, opening in the positive direction of the Z axis, when viewed in a plan view in the Y axis direction. The second core 3 has a base portion 31 and a pair of shaft portions 32.

[0035] The base 31 has a rectangular parallelepiped shape, and the thickness direction of the base 31 is along the Z axis.

[0036] The pair of shaft portions 32 protrude in the positive direction of the Z axis from both ends of the base portion 31 in the X axis direction. The pair of shaft portions 32 have the same shape. The shaft portion 32 has a first shaft portion 320 and a second shaft portion (thin shaft portion 6).

[0037] The first shaft portion 320 protrudes in the positive direction of the Z axis from the end of the base portion 31 in the X axis direction. The shape of the first shaft portion 320 is a rectangular parallelepiped. In this embodiment, the cross-sectional shape of the first shaft portion 320 along the XY plane is a square with a side length of the third length A3 (see FIG. 3 ).

[0038] The thin shaft portion 6 protrudes from the tip of the first shaft portion 320 in the positive direction of the Z axis. The thin shaft portion 6 is thinner than the other portions of the shaft portion 32. As shown in FIG. 3 , the thin shaft portion 6 has a truncated cone shape that becomes thinner in the positive direction of the Z axis. In this embodiment, when viewed in a plane in a direction perpendicular to the facing direction D1 (e.g., the Y axis direction), the side surfaces 64 of the thin shaft portion 6 (e.g., both ends in the X axis direction) have an arc shape. More specifically, in this embodiment, when viewed in a plane in a direction perpendicular to the facing direction D1, the side surfaces 64 of the thin shaft portion 6 have an arc shape that forms a part of a perfect circle. In other words, the generatrix of the truncated cone-shaped thin shaft portion 6 has an arc shape that forms a part of a perfect circle.

[0039] The side surface 64 of the thin shaft portion 6 of the first core 2 and the side surface 64 of the thin shaft portion 6 of the second core 3 form a semicircular arc shape in a plan view in a direction perpendicular to the opposing direction D1.

[0040] (2.2) Configuration of the Frame Member The pair of frame members 5 are arranged to cover the pair of shaft portions 22 of the first core 2 and the pair of shaft portions 32 of the second core 3. In other words, the frame members 5 are arranged to cover the shaft portions 22 of the first core 2 and the shaft portions 32 of the second core 3. The coil 4 is wound around the frame members 5. In other words, in this embodiment, the coil 4 is wound around the shaft portions 22 and 32 via the frame members 5.

[0041] The frame member 5 is made of a non-magnetic and non-conductive material. The frame member 5 is made of, for example, synthetic resin. The frame member 5 has a strength sufficient to prevent the coil 4 from approaching the thin shaft portion 6 of the shaft portion 22 (or the shaft portion 32) when the coil 4 is wound around the frame member 5. This allows the side surface 64 and the contact surface 63 of the thin shaft portion 6 to be more reliably separated from the coil 4. This further prevents leakage magnetic flux that crosses the contact surface 63 from interlinking with the coil 4, thereby further reducing eddy current loss.

[0042] (2.3) Coil Configuration The pair of coils 4 are wound around the pair of shaft portions 22 of the first core 2 and the pair of shaft portions 32 of the second core 3. In other words, the coils 4 are wound around the shaft portions 22 of the first core 2 and the shaft portions 32 of the second core 3. In this embodiment, the coils 4 are wound around the shaft portions 22 of the first core 2 and the shaft portions 32 of the second core 3 via the frame member 5.

[0043] Both ends of the coil 4 are electrically connected to, for example, an electric circuit. When a current flows through the coil 4 in response to the operation of the electric circuit, a magnetic field is generated, and a magnetic flux passes through the first core 2 and the second core 3.

[0044] (3) Modifications Modifications of the above embodiment are listed below.

[0045] (3.1) Modification 1 A magnetic component 1 according to modification 1 will be described with reference to FIG.

[0046] In the first modification, the shape of the side surface 64A of the thin shaft portion 6A is an arc that forms a part of an ellipse when viewed from a plane perpendicular to the facing direction D1. That is, the generatrices of the truncated cone-shaped thin shaft portion 6 are arc-shaped that form a part of an ellipse. The shape of the contact surface 63A in the first modification is, for example, a perfect circle.

[0047] In the first modification, a first length A5, which is the length between the first end 61A and the second end 62A in the facing direction D1, is longer than a second length A2, which is the depth of the recess in the thin shaft portion 6A. In other words, the first length A5, which is the length between the first end 61A and the second end 62A in the facing direction D1, is longer than a second length A2, which is the difference between a third length A3, which is the width of the first end 61A in a direction perpendicular to the facing direction D1 (e.g., the X-axis direction), and a fourth length A4, which is the width of the second end 62A in a direction perpendicular to the facing direction D1.

[0048] For example, the second length A2 in Modification 1 is equal to the second length A2 in the above embodiment. That is, the first length A5 of thin shaft portion 6A in Modification 1 is longer than the first length A1 of thin shaft portion 6 in the above embodiment. When the lengths in the facing direction D1 of shank 22 (or shank 32) of Modification 1 and shank 22 (or shank 32) of the above embodiment are equal, the proportion of thin shaft portion 6A in shank 22 (or shank 32) of Modification 1 is greater than the proportion of thin shaft portion 6 in shank 22 (or shank 32) of the above embodiment.

[0049] The two dashed-dotted lines in Fig. 5 are spaced from the contact surface 63A in the facing direction D1 by the first length A1 in the above embodiment (see Fig. 3). That is, the two dashed-dotted lines in Fig. 5 indicate the position of the first end 61 of the thin shaft portion 6 in the above embodiment. In the magnetic component 1 of Modification 1, the dashed-dotted line portion of the thin shaft portion 6A is farther from the coil 4 than the first end 61 of the thin shaft portion 6 in the above embodiment. This makes it possible to prevent leakage flux generated between the dashed-dotted line portion of the thin shaft portion 6A of the first core 2 and the dashed-dotted line portion of the thin shaft portion 6A of the second core 3 from interlinking with the coil 4.

[0050] Therefore, according to the magnetic component 1 of the first modification, it is possible to further suppress the leakage magnetic flux that crosses the contact surface 63A from interlinking with the coil 4, thereby further reducing eddy current loss.

[0051] (3.2) Modification 2 A magnetic component 1 according to modification 2 will be described with reference to FIG.

[0052] The thin shaft portion 6B of Modification 2 has a rectangular truncated shape that becomes thinner toward the tip. In Modification 2, the side surfaces 64B of the thin shaft portion 6B (e.g., both ends in the X-axis direction) are linear in plan view in a direction perpendicular to the facing direction D1 (e.g., the Y-axis direction). This makes it easier to manufacture the core (first core 2 or second core 3) than when the side surfaces of the thin shaft portion are arc-shaped.

[0053] As shown in FIG. 7 , the contact surface 63B of the thin shaft portion 6B of Modification 2 has a square shape. The diameter of the contact surface 63B of Modification 2 is the width of the second end 62B in a direction perpendicular to the facing direction D1, which is the fourth length A4. The area of ​​the contact surface 63B is smaller than the cross-sectional area of ​​the first shaft portion 220 along the XY plane. In addition, in this embodiment, the area of ​​the contact surface 63B is the area where the magnetic flux density at the contact surface 63B when current is flowing through the coil 4 is less than the saturation magnetic flux density. In other words, the area of ​​the contact surface 63B is smaller than the cross-sectional area of ​​the first shaft portion 220 and larger than the area of ​​the contact surface when the magnetic flux density at the contact surface 63B is the saturation magnetic flux density.

[0054] 6 , in Modification 2, a first length A5, which is the length between the first end 61B and the second end 62B in the facing direction D1, is longer than a second length A2, which is the depth of the recess in the thin shaft portion 6B. In other words, the first length A5, which is the length between the first end 61B and the second end 62B in the facing direction D1, is longer than a second length A2, which is the difference between a third length A3, which is the width of the first end 61B in a direction perpendicular to the facing direction D1 (e.g., the X-axis direction), and a fourth length A4, which is the width of the second end 62B in a direction perpendicular to the facing direction D1.

[0055] For example, the second length A2 in Modification 2 is equal to the second length A2 in the above embodiment (see FIG. 3 ). That is, the first length A5 of thin shaft portion 6B in Modification 2 is longer than the first length A1 of thin shaft portion 6 in the above embodiment. When the lengths in the opposing direction D1 of shank 22 (or shank 32) of Modification 2 and shank 22 (or shank 32) of the above embodiment are equal, the proportion of thin shaft portion 6B in shank 22 (or shank 32) of Modification 2 is greater than the proportion of thin shaft portion 6 in shank 22 (or shank 32) of the above embodiment.

[0056] The two dashed-dotted lines in Fig. 6 are spaced from the contact surface 63B in the facing direction D1 by the first length A1 in the above embodiment. That is, the two dashed-dotted lines in Fig. 6 indicate the position of the first end 61 of the thin shaft portion 6 in the above embodiment. In the magnetic component 1 of Modification 2, the dashed-dotted line portion of the thin shaft portion 6B is farther from the coil 4 than the first end 61 of the thin shaft portion 6 in the above embodiment. This makes it possible to prevent leakage flux generated between the dashed-dotted line portion of the thin shaft portion 6B of the first core 2 and the dashed-dotted line portion of the thin shaft portion 6B of the second core 3 from interlinking with the coil 4.

[0057] Therefore, according to the magnetic component 1 of the second modification, it is possible to further suppress the leakage magnetic flux that crosses the contact surface 63B from interlinking with the coil 4, thereby further reducing eddy current loss.

[0058] (3.3) Modification 3 A magnetic component 1A according to modification 3 will be described with reference to FIG.

[0059] The magnetic component 1A includes a first core 2A and a second core 3A. The first core 2A and the second core 3A are so-called EI cores.

[0060] The first core 2A of the third modification has an E-shape that opens in the negative direction of the Z axis when viewed in a plan view in the Y axis direction. The first core 2A has a base 21A, a pair of shaft portions 22A, and a central shaft portion 23A (shaft portion).

[0061] The base portion 21A has a rectangular parallelepiped shape, and the thickness direction of the base portion 21A is along the Z axis.

[0062] The pair of shaft portions 22A protrude in the negative direction of the Z axis from both ends of the base portion 21A in the X axis direction. Similar to the pair of shaft portions 22 in the above embodiment, the pair of shaft portions 22A are wound with the coil 4 via the frame member 5. The pair of shaft portions 22A have the same shape. The shaft portion 22A has a first shaft portion 220A and a second shaft portion (thin shaft portion 6).

[0063] The first shaft portion 220A protrudes in the negative direction of the Z axis from the end of the base portion 21A in the X axis direction. The shape of the first shaft portion 220A is a rectangular parallelepiped. In the third modification, the cross-sectional shape of the first shaft portion 220A along the XY plane is a square.

[0064] The thin shaft portion 6 protrudes in the negative Z-axis direction from the tip of the first shaft portion 220A. The thin shaft portion 6 is thinner than the other portions of the shaft portion 22A. As shown in FIG. 8 , the thin shaft portion 6 has a truncated cone shape that becomes thinner in the negative Z-axis direction. In Modification 3, in a plan view in a direction perpendicular to the facing direction D1 (e.g., the Y-axis direction), the side surfaces 64 of the thin shaft portion 6 (e.g., both ends in the X-axis direction) have an arc shape. A contact surface 63 is formed at the tip of the thin shaft portion 6. The contact surface 63 is in contact with the main surface 310 of the second core 3A.

[0065] The central shaft portion 23A is disposed between the pair of shaft portions 22A in a direction perpendicular to the opposing direction D1 (the X-axis direction in the example of FIG. 8 ). The coil 4 is wound around the central shaft portion 23A via a frame member 5. The central shaft portion 23A has a first shaft portion 230A and a second shaft portion (thin shaft portion 6).

[0066] The first shaft portion 230A protrudes in the negative direction of the Z axis from the center of the base portion 21A in the X axis direction. The shape of the first shaft portion 230A is a rectangular parallelepiped. In the third modification, the cross-sectional shape of the first shaft portion 230A along the XY plane is a square.

[0067] The thin shaft portion 6 protrudes in the negative Z-axis direction from the tip of the first shaft portion 230A. The thin shaft portion 6 is thinner than the other portions of the central shaft portion 23A. As shown in FIG. 8 , the thin shaft portion 6 has a truncated cone shape that becomes thinner in the negative Z-axis direction. In Modification 3, in a plan view in a direction perpendicular to the facing direction D1 (e.g., the Y-axis direction), the side surfaces 64 of the thin shaft portion 6 (e.g., both ends in the X-axis direction) are arc-shaped. A contact surface 63 is formed at the tip of the thin shaft portion 6. The contact surface 63 is in contact with the main surface 310 of the second core 3A.

[0068] The second core 3A of the third modification has a rectangular plate shape. The normal direction of the main surface 310 of the second core 3A is along the facing direction D1.

[0069] The main surface 310 is in contact with the thin shaft portion 6 of the first core 2A. More specifically, the main surface 310 is in contact with the contact surfaces 63 of the thin shaft portions 6 of the pair of shaft portions 22A and the contact surface 63 of the thin shaft portion 6 of the central shaft portion 23A.

[0070] When viewed from a direction perpendicular to the opposing direction D1, the thin shaft portion 6 of the first core 2A and the second core 3A form an L-shape or a T-shape. More specifically, the thin shaft portions 6 of the pair of shaft portions 22A of the first core 2A and the second core 3A form an L-shape. Furthermore, the central shaft portion 23A of the first core 2A and the second core 3A form a T-shape.

[0071] In the magnetic component 1A of Modification 3, as in the above-described embodiment, Modification 1, and Modification 2, the thin shaft portion 6 becomes thinner as it approaches the contact surface 63. Therefore, in the direction perpendicular to the facing direction D1, the side surface 64 of the thin shaft portion 6 and the contact surface 63 that contacts the second core 3A are farther from the coil 4 than other parts of the shaft portion 22A. This makes it possible to suppress leakage flux that crosses the contact surface 63 from interlinking with the coil 4, thereby reducing eddy current loss.

[0072] (3.4) Modification 4 A magnetic component 1B according to modification 4 will be described with reference to FIG.

[0073] The magnetic component 1B includes a first core 2A and a second core 3B. The first core 2A and the second core 3B are so-called EE cores. However, the first core 2A and the second core 3B may also be so-called EER cores or PQ cores. The first core 2A and the second core 3B of the fourth modification are symmetrical with respect to the opposing direction D1.

[0074] The configuration of the first core 2A is the same as that of the first core 2A of the fourth modification, and therefore a description thereof will be omitted.

[0075] The second core 3B of the fourth modification has an E-shape that opens in the positive direction of the Z axis when viewed in a plan view in the Y axis direction. The second core 3B has a base 31B, a pair of shaft portions 32B, and a central shaft portion 33B (shaft portion).

[0076] The base portion 31B has a rectangular plate shape, and the thickness direction of the base portion 31B is along the Z axis.

[0077] The pair of shaft portions 32B protrude in the positive direction of the Z axis from both ends of the base portion 31B in the X axis direction. Similar to the pair of shaft portions 22A of Modification 3, the pair of shaft portions 32B are wound with the coil 4 via the frame member 5. The pair of shaft portions 32B have the same shape. The shaft portion 32B has a first shaft portion 320B and a second shaft portion (thin shaft portion 6).

[0078] The first shaft portion 320B protrudes in the positive direction of the Z axis from the end of the base portion 31B in the X axis direction. The first shaft portion 320B has a rectangular parallelepiped shape.

[0079] The thin shaft portion 6 protrudes in the positive direction of the Z axis from the tip of the first shaft portion 320B. The thin shaft portion 6 is thinner than the other portions of the shaft portion 32B. As shown in FIG. 9 , the shape of the thin shaft portion 6 is a truncated cone that becomes thinner in the positive direction of the Z axis. In the fourth modification, in a plan view in a direction perpendicular to the facing direction D1 (e.g., the Y axis direction), the side surfaces 64 of the thin shaft portion 6 (e.g., both ends in the X axis direction) are arc-shaped. A contact surface 63 is formed at the tip of the thin shaft portion 6. The contact surface 63 of the shaft portion 32B of the second core 3B contacts the contact surface 63 of the shaft portion 22A of the second core 3A.

[0080] The side surface 64 of the shaft portion 22A of the first core 2A and the side surface 64 of the shaft portion 32B of the second core 3B form a semicircular arc shape in a plan view in a direction perpendicular to the opposing direction D1.

[0081] The central shaft portion 33B is disposed between the pair of shaft portions 32B in a direction perpendicular to the opposing direction D1 (the X-axis direction in the example of FIG. 9 ). The coil 4 is wound around the central shaft portion 33B via a frame member 5. The central shaft portion 33B has a first shaft portion 330B and a second shaft portion (thin shaft portion 6).

[0082] The first shaft portion 330B protrudes in the positive direction of the Z axis from the center of the base portion 31B in the X axis direction. The shape of the first shaft portion 330B is a rectangular parallelepiped. In the fourth modification, the cross section of the first shaft portion 330B along the XY plane is a square.

[0083] The thin shaft portion 6 protrudes in the positive direction of the Z axis from the tip of the first shaft portion 330B. The thin shaft portion 6 is thinner than the other portions of the central shaft portion 33B. As shown in FIG. 9 , the thin shaft portion 6 has a truncated cone shape that becomes thinner in the positive direction of the Z axis. In the fourth modification, in a plan view in a direction perpendicular to the facing direction D1 (e.g., the Y axis direction), the side surfaces 64 of the thin shaft portion 6 (e.g., both ends in the X axis direction) have an arc shape. A contact surface 63 is formed at the tip of the thin shaft portion 6. The contact surface 63 of the central shaft portion 33B of the second core 3B contacts the contact surface 63 of the central shaft portion 23A of the first core 2A.

[0084] The side surface 64 of the central shaft portion 23A of the first core 2A and the side surface 64 of the central shaft portion 33B of the second core 3B form a semicircular arc shape in a plan view in a direction perpendicular to the opposing direction D1.

[0085] In the magnetic component 1B of Modification 4, as in the above-described embodiment, Modification 1, Modification 2, and Modification 4, the thin shaft portion 6 becomes thinner as it approaches the contact surface 63. Therefore, in the direction perpendicular to the facing direction D1, the side surface 64 of the thin shaft portion 6 and the contact surface 63 that contacts the second core 3B are farther from the coil 4 than other parts of the shaft portion 22A. This makes it possible to suppress leakage flux that crosses the contact surface 63 from interlinking with the coil 4, thereby reducing eddy current loss.

[0086] (3.5) Other Modifications It is not essential that the magnetic component 1 includes the frame member 5. The coil 4 may be provided so as not to come close to the thin shaft portion 6 of the shaft portion 22, for example, by being solidified with resin or the like.

[0087] In the above embodiment and each modified example, a case has been described in which a part of the shaft portion 22 is the thin shaft portion 6. However, the entire shaft portion 22 may be the thin shaft portion 6 having a tapered shape.

[0088] The first shaft portion 220 of the shaft portion 22 may be cylindrical, or may be polygonal pillar-shaped other than a rectangular parallelepiped.

[0089] (Aspects) As is clear from the above-described embodiments and modifications, a magnetic component (1; 1A; 1B) according to a first aspect includes a first core (2; 2A), a second core (3; 3A; 3B), and a coil (4). The first core (2; 2A) and the second core (3; 3A; 3B) are formed of a magnetic material and are arranged to face each other in an opposing direction (D1) and to be in contact with each other in part. The coil (4) is wound around the first core (2; 2A). The first core (2; 2A) has a shaft portion (22; 22A; 23A) around which the coil (4) is wound and which is in contact with the second core (3; 3A; 3B). The shaft portion (22; 22A; 23A) has a thin shaft portion (6; 6A; 6B). The thin shaft portion (6; 6A; 6B) has a contact surface (63; 63A; 63B) that contacts the second core (3; 3A; 3B) in the facing direction (D1). The shape of the thin shaft portion (6; 6A; 6B) tapers toward the contact surface (63; 63A; 63B) along the facing direction (D1).

[0090] According to this aspect, it is possible to reduce eddy current loss due to leakage magnetic flux.

[0091] In the magnetic component (1; 1A; 1B) according to the second aspect, in the first aspect, the shape of the side surface (64; 64A) of the thin shaft portion (6; 6A) is arc-shaped when viewed from a direction perpendicular to the opposing direction (D1).

[0092] In the magnetic component (1; 1A; 1B) according to the third aspect, in the first aspect, the shape of the side surface (64B) of the thin shaft portion (6B) is linear when viewed from a direction perpendicular to the opposing direction (D1).

[0093] According to this aspect, the first core (2) can be easily manufactured.

[0094] In a magnetic component (1; 1A; 1B) according to a fourth aspect, in any one of the first to third aspects, the thin shaft portion (6A; 6B) has a first end (61A; 61B) and a second end (62A; 62B) that are opposite ends in the facing direction (D1). The contact surface (63A; 63B) is formed at the second end (62A; 62B). A first length (A5) between the first end (61A; 61B) and the second end (62A; 62B) in the facing direction (D1) is longer than a second length (A2) that is the difference between the width (third length A3) of the first end (61A; 61B) in a direction perpendicular to the facing direction (D1) and the width (fourth length A4) of the second end (62A; 62B) in a direction perpendicular to the facing direction (D1).

[0095] According to this aspect, eddy current loss can be further reduced.

[0096] In the magnetic part (1; 1A; 1B) according to the fifth aspect, in any of the first to fourth aspects, the area of ​​the contact surface (63; 63A; 63B) is an area in which the magnetic flux density at the contact surface (63; 63A; 63B) when a current flows through the coil (4) is less than the saturation magnetic flux density.

[0097] According to this aspect, it is possible to further reduce eddy current loss due to leakage magnetic flux.

[0098] In a magnetic component (1; 1B) according to a sixth aspect, in any one of the first to fifth aspects, the first core (2; 2A) and the second core (3; 3B) are symmetrical in the opposing direction (D1), and the coil (4) is wound around the first core (2; 2A) and the second core (3; 3B).

[0099] According to this aspect, it is possible to further reduce eddy current loss due to leakage magnetic flux.

[0100] In a magnetic component (1A) according to a seventh aspect, in any one of the first to fifth aspects, the second core (3A) has a plate-like shape, and the thin shaft portion (6) of the first core (2A) and the second core (3A) form an L-shape or a T-shape when viewed from a direction perpendicular to the opposing direction (D1).

[0101] The configurations other than the first aspect are not essential for the magnetic component (1) and can be omitted as appropriate.

[0102] 1. 1A, 1B Magnetic components 2. 2A First section 22. 22A Shaft 23A Central shaft (shaft) 3. 3A, 3B Second section 4. Coil 6. 6A, 6B Thin shaft 61. 61A, 61B First end 62. 62A, 62B Second end 63. 63A, 63B Contact surface 64. 64A, 64B Side surface A1 First length A2 Second length A3 Third length A4 Fourth length D1 Relative direction

Claims

1. A magnetic component comprising: a first core and a second core formed of a magnetic material, facing each other in an opposing direction and arranged so that parts of the core are in contact with each other; and a coil wound around the first core, wherein the first core has a shaft portion around which the coil is wound and which is in contact with the second core, and the shaft portion has a thin shaft portion formed with a contact surface which is in contact with the second core in the opposing direction, and the shape of the thin shaft portion tapers as it approaches the contact surface along the opposing direction.

2. The magnetic component according to claim 1, wherein the shape of the side surface of the thin shaft portion is arcuate when viewed from a direction perpendicular to the facing direction.

3. The magnetic component according to claim 1, wherein the shape of the side surface of the thin shaft portion is linear when viewed in a direction perpendicular to the facing direction.

4. A magnetic component according to any one of claims 1 to 3, wherein the thin shaft portion has a first end and a second end which are opposite ends in the opposing direction, the contact surface is formed at the second end, and a first length between the first end and the second end in the opposing direction is longer than a second length which is the difference between the width of the first end in a direction perpendicular to the opposing direction and the width of the second end in the direction perpendicular to the opposing direction.

5. A magnetic component according to any one of claims 1 to 4, wherein the area of ​​the contact surface is an area in which the magnetic flux density at the contact surface when a current flows through the coil is less than the saturation magnetic flux density.

6. A magnetic component according to any one of claims 1 to 5, wherein the first core and the second core are symmetrical in the opposing direction, and the coil is wound around the first core and the second core.

7. A magnetic component according to any one of claims 1 to 5, wherein the second core is shaped like a plate, and the thin shaft portion of the first core and the second core form an L-shape or a T-shape when viewed from a direction perpendicular to the opposing direction.

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