Coil device

Abstract

To provide a coil device capable of preventing damage to a covering part of a wire.SOLUTION: A coil device includes: a first magnetic material part containing a magnetic material and having a plate-shaped part and a protruding part protruding from the plate-shaped part; a wire having a conductor part and an insulating covering part covering the conductor part and having a winding part forming a winding layer winding the protruding part; and a second magnetic material part containing a magnetic material and a resin, and covering at least the winding part and the protruding part of the first magnetic material part. In a predetermined cross section in which a wire cross section which is a cross section of the wire is observed, a first layer uppermost wire cross section which is most separated from the plate-like part among the wire cross sections included in a first layer which is directly wound around the protruding part in the winding part includes a part which is separated from the plate-like part as compared with a tip of the protruding part of the protruding part, and the first layer uppermost wire cross section is in contact with the protruding part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a coil device used as an inductor element or the like. [Background technology]

[0002] A coil device has been proposed that combines two types of core parts and winding parts with different resin and magnetic material content ratios. By using two types of core parts with different resin and magnetic material content ratios, such a coil device can relieve stress and prevent cracks from occurring.

[0003] In such a coil device, a magnetic material is arranged to cover the winding portion, which is advantageous from the viewpoint of improving inductance. However, in such a coil device, particles constituting the core portion with a higher resin content and greater fluidity than the two types of core portions may migrate into the winding portion during compression or other processes in the manufacturing process. When such particles migrate, friction occurs with the insulating coating of the wire constituting the winding portion, which may damage the insulating coating of the wire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-199734 [Patent Document 1] Japanese Patent Application Publication No. 2020-113742 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure has been made in view of the above circumstances, and provides a coil device that prevents damage to the coating of the wire. [Means for solving the problem]

[0006] A coil device according to the present disclosure includes: a first magnetic material portion containing a magnetic substance and having a plate-shaped portion and a protruding portion protruding from the plate-shaped portion; a wire having a conductor portion and an insulating covering portion covering the conductor portion, the wire having a winding portion forming a winding layer that winds around the protrusion; a second magnetic material portion that contains a magnetic substance and a resin and covers at least the winding portion and the protruding portion of the first magnetic material portion; In a predetermined cross section including the winding axis of the winding section where a wire cross section, which is a cross section of the wire, is observed, the first layer's topmost wire cross section, which is the farthest from the plate-shaped portion among the wire cross sections included in the first layer that is directly wound around the protrusion in the winding section, includes a portion that is farther from the plate-shaped portion than the protrusion tip that is the farthest from the plate-shaped portion among the protrusions, and the coating portion in the first layer's topmost wire cross section is in contact with the protrusion.

[0007] In the coil device according to the present disclosure, the cross section of the uppermost wire of the first layer prevents particles of the second magnetic material portion from entering the interior of the winding portion, and can effectively prevent damage to the wire and the resulting short circuit defects.

[0008] Furthermore, for example, the tip of the protruding portion may be farther away from the plate-shaped portion than the center of the cross section of the topmost wire of the first layer.

[0009] By arranging the uppermost wire cross section of the first layer in such a position, it is possible to suitably prevent the problem of the position of the uppermost wire cross section of the first layer being shifted during compression, etc. Furthermore, in such a coil device, the winding portion can be easily formed during manufacturing.

[0010] Furthermore, for example, among the wire cross sections included in the second layer that is wound around the protruding portion and overlaps the first layer in the winding portion, the uppermost wire cross section of the second layer that is farthest from the plate-shaped portion may be closer to the plate-shaped portion than the uppermost wire cross section of the first layer.

[0011] A coil device having such a winding portion is less likely to collapse, and can more effectively prevent magnetic powder of the second magnetic material portion from entering the inside of the winding portion.

[0012] Furthermore, for example, the first layer uppermost wire cross section may be the farthest from the plate-shaped portion among all the wire cross sections included in the winding portion.

[0013] A coil device having such a winding portion is less likely to collapse, and can more effectively prevent magnetic powder and the like of the second magnetic material portion from moving into the interior of the winding portion.

[0014] Furthermore, for example, the uppermost wire cross section of the first layer may be closest to the winding axis among the wire cross sections included in the first layer.

[0015] Furthermore, for example, the side surface of the protrusion surrounding the winding axis may be inclined so as to approach the winding axis as it moves away from the plate-shaped portion, and the wire cross section included in the first layer may be arranged along the inclination of the side surface of the protrusion.

[0016] A coil device having such a winding portion is less likely to form gaps around the top wire cross section of the first layer that allow magnetic powder from the second magnetic material portion to enter the inside of the winding portion, making it possible to more effectively prevent damage to the wire coating, etc.

[0017] Furthermore, for example, the thickness of the second magnetic material portion covering the tip of the protruding portion along the direction away from the plate-shaped portion may be equal to or less than twice the average diameter of the cross section of the wire.

[0018] In such a coil device, the second magnetic material portion, which contains a small proportion of magnetic material, is thin, so that the magnetic properties of the core can be improved even if the device is small. [Brief explanation of the drawings]

[0019] [Figure 1]FIG. 1 is a partial perspective view of a coil device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the coil device shown in FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of the periphery of the winding portion in the cross section shown in FIG. [Figure 4] FIG. 4 is an enlarged schematic view of the periphery of a winding portion in a coil device according to a first modified example. [Figure 5] FIG. 5 is an enlarged schematic view of the periphery of a winding portion in a coil device according to a second modified example. [Figure 6] FIG. 6 is an enlarged schematic view of the periphery of a winding portion in a coil device according to a third modified example. [Figure 7] FIG. 7 is an enlarged schematic view of the periphery of a winding portion in a coil device according to a fourth modified example. [Figure 8] FIG. 8 is an enlarged schematic view of the periphery of the first layer of the winding portion in a coil device according to a fifth modified example. [Figure 9] FIG. 9 is an enlarged schematic view of the periphery of the first layer of the winding portion in a coil device according to a sixth modified example. [Figure 10] FIG. 10 is an enlarged schematic view of the periphery of a cross section of the top wire of the first layer according to another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the contents shown in the drawings are merely shown schematically and exemplarily to facilitate understanding of the present disclosure, and the appearance and dimensional ratios may differ from the actual product. Furthermore, the present disclosure is not limited to the following embodiments.

[0021] First embodiment Fig. 1 is a partial perspective view of a coil device 10 according to an embodiment of the present disclosure. As shown in Fig. 1, the coil device 10 has a first magnetic material portion 20, a second magnetic material portion 30, and a wire 40. The coil device 10 also has a pair of terminal electrodes (not shown in Fig. 1) connected to the wire 40. In Fig. 1, the second magnetic material portion 30 is shown in perspective with imaginary lines to facilitate understanding of the internal structure of the coil device 10.

[0022] 1, the coil device 10 has a substantially rectangular parallelepiped outer shape, and the first magnetic material portion 20 is disposed near the bottom surface of the coil device 10. The first magnetic material portion 20 contains a magnetic substance, and has a plate-like portion 22 in the shape of a substantially rectangular plate, and a cylindrical protruding portion 24 protruding upward from the center of the plate-like portion 22.

[0023] The first magnetic material portion 20 is formed, for example, from a sintered core of a magnetic material that does not contain resin, or a core containing a magnetic material and resin that is produced by compression molding or injection molding granules containing magnetic powder that constitutes the magnetic material and resin as a binder. The magnetic powder is not particularly limited, but metal magnetic powders such as sendust (Fe-Si-Al; iron-silicon-aluminum), Fe-Si-Cr (iron-silicon-chromium), permalloy (Fe-Ni), carbonyl iron-based, carbonyl Ni-based, amorphous powder, and nanocrystal powder are preferably used.

[0024] However, the magnetic powder may be ferrite magnetic powder such as Mn-Zn or Ni-Cu-Zn. When the first magnetic material portion 20 includes a magnetic material and a resin, the binder resin included in the first magnetic material portion 20 is not particularly limited, and examples thereof include epoxy resin, phenol resin, acrylic resin, polyester resin, polyimide, polyamideimide, silicone resin, and combinations thereof.

[0025] 2, the first magnetic material portion 20 functions as a core of the coil device 10 together with the second magnetic material portion 30 described later. The plate-shaped portion 22 has a larger projected area when viewed from above than the protruding portion 24. The thickness of the plate-shaped portion 22 can be approximately 10 to 40% of the overall thickness of the coil device 10, but is not particularly limited thereto. The shape of the plate-shaped portion 22 is not limited to a substantially rectangular plate, and may be a polygonal plate, a circular plate, an elliptical plate, or any other shape besides a rectangular plate.

[0026] The protruding height of protruding portion 24 is not particularly limited, but can be about 20 to 60% of the overall thickness of coil device 10. The outer peripheral shape of protruding portion 24 shown in Fig. 1 is not limited to a circle, and may be an ellipse, a polygon, or any other shape other than a circle. However, from the viewpoint of winding wire 40 in close contact with the outer periphery of protruding portion 24, a circle or an ellipse is preferable.

[0027] As shown in Fig. 1, wire 40 has a winding portion 42 that forms two or more winding layers that wind around protrusion 24, and a wire end portion 41 that is drawn out from winding portion 42. Also, as shown in Fig. 3, which is an enlarged cross-sectional view, wire 40 has a conductive conductor portion (see conductor portion 51b in Fig. 3, etc.) and an insulating coating portion that coats the conductor portion (see coating portion 51a in Fig. 3, etc.). In winding portion 42 in a predetermined cross-section as shown in Figs. 2 and 3, the coating portion appears on the outer periphery of the wire cross-section (see first layer top-stage wire cross-section 51 in Fig. 3, etc.).

[0028] The conductor portion of wire 40 is made of, for example, Cu, Al, Fe, Ag, Au, phosphor bronze, etc. Examples of materials for the coating formed on the surface of the conductor portion of wire 40 include polyurethane, polyamideimide, polyimide, polyester, polyester-imide, and polyester-nylon.

[0029] A portion of wire 40 is wound around protruding portion 24 to form winding portion 42. Fig. 2 is a cross-sectional view of winding portion 42 taken along a predetermined cross section including winding axis 40a, and Fig. 3, which is an enlarged partial view of the cross-section, shows wire cross sections 51-54, 61-64, 71-74, 81-84, and 91-94, which are cross sections of wire 40, corresponding to the number of turns of wire 40 around protruding portion 24. Note that, although the number of turns of wire 40 around protruding portion 24 in coil device 10 shown in Figs. 2 and 3 is 20 turns, the number of turns of winding portion 42 is not particularly limited.

[0030] As shown in FIG. 2, the winding portion 42 has two or more winding layers. In this embodiment, the winding layers are a first layer 50, a second layer 60, a third layer 70, a fourth layer 80, and a fifth layer 90. The first to fifth layers 50-90 are arranged along a second direction D2 that is perpendicular to the winding axis 40a. The first layer 50 is wound directly around the protrusion 24, for example, by being pressed against the protrusion side surface 24a of the protrusion 24. The second layer 60 is wound by being pressed against the first layer 50 on the inner periphery. Similarly to the second layer 60, the third layer 70, the fourth layer 80, and the fifth layer 90 are also wound by being pressed against the inner periphery winding layer. Furthermore, in the winding portion 42, adjacent wire cross sections 51-54, 61-64, 71-74, 81-84, and 91-94 are in close contact with each other due to, for example, fusion of the coating. However, due to spring back of the wire 40 or the like, local gaps may be formed between the wire cross sections 51 to 54, 61 to 64, 71 to 74, 81 to 84, and 91 to 94.

[0031] In this way, the winding portion 42 is formed by winding the wire 40 around the winding portion 42 using a winding machine or the like, so that the first layer 50 of the winding portion 42 contacts the protruding portion 24, or the first to fifth layers 50-90 contact each other, which is preferable from the viewpoint of increasing the winding density. However, the winding portion 42 can also be formed of an air-core coil. The number of winding layers in the winding portion 42 is not particularly limited, and any number of two or more winding layers can be formed around the winding portion 42. Furthermore, in the winding portion 42, all winding layers may be wound while pressed against the inner winding layer, or some or all winding layers may be wound with a gap between them and the inner winding layer.

[0032] 2, wire 40 is a round wire having a substantially circular cross section 51-54, 61-64, 71-74, 81-84, 91-94. However, wire 40 is not limited to a round wire, and a rectangular wire having a substantially rectangular cross section may also be used. Furthermore, wire 40 is not limited to a solid wire having conductor portion 51b and coating portion 51a formed concentrically, and may have multiple conductor portions, such as a twisted wire.

[0033] 1, the wire 40 has a pair of wire ends 41 drawn out from both ends of the winding portion 42, and each wire end 41 is connected to a terminal electrode portion (not shown) formed on the side surface 22a and bottom surface 22b of the plate-shaped portion 22. The terminal electrode portion may be, for example, a metal terminal made of copper or a copper alloy bonded to the plate-shaped portion 22, or may be a baked electrode containing silver or a silver alloy, or a metal film electrode formed by plating or the like.

[0034] As shown in FIG. 2 , the second magnetic material portion 30 covers at least the winding portion 42 of the wire 40 and the protruding portion 24 of the first magnetic material portion 20, and together with the first magnetic material portion 20, constitutes the core of the coil device 10. The second magnetic material portion 30 contains a magnetic material and a resin. Like the first magnetic material portion 20, the second magnetic material portion 30 contains a magnetic material, but the magnetic material content is lower than that of the first magnetic material portion 20. Because the second magnetic material portion 30 contains a lower magnetic material content, it can be disposed around the winding portion 42 in a fluid state during manufacturing, which allows the second magnetic material portion 30 to be tightly attached to the winding portion 42 from the outer circumferential side and the upper side without any gaps.

[0035] The magnetic material contained in the second magnetic material portion 30 can be a metal magnetic powder or a ferrite magnetic powder similar to those exemplified as the magnetic powder contained in the first magnetic material portion 20. Similarly to the first magnetic material portion 20, examples of the binder resin contained in the second magnetic material portion 30 include epoxy resin, phenol resin, acrylic resin, polyester resin, polyimide, polyamideimide, silicone resin, and combinations thereof.

[0036] The second magnetic material portion 30 is combined with the first magnetic material portion 20 having only one plate-shaped portion 22 as shown in Figures 1 and 2, and is arranged not only on the outer periphery of the winding portion 42, but also on the upper side of the winding portion 42 and on the upper side of the protrusion 24.

[0037] The second magnetic material portion 30 is manufactured by compression molding, etc. For example, the second magnetic material portion 30 can be obtained by putting an intermediate product in which a wound portion 42 of a wire 40 is formed around the protruding portion 24 of the first magnetic material portion 20, and a mixture of magnetic powder and binder resin, which are the materials for the second magnetic material portion 30, into a cavity and compressing the whole.

[0038] From the viewpoint of improving inductance, the content of the magnetic material in the second magnetic material portion 30 is preferably 50% or more, and more preferably 70% or more. The magnetic material contained in the second magnetic material portion 30 may be composed of two or more types of magnetic powder having different average particle sizes. In such a second magnetic material portion 30, the particle size distribution of the magnetic powder has multiple peaks and is distributed over a wide range, so that magnetic powder with a small particle size can easily enter the gaps between the wires.

[0039] 3 is an enlarged cross-sectional view showing a predetermined cross section including winding axis 40a of winding portion 42 shown in FIG. 2, and wire cross sections 51 to 54, 61 to 64, 71 to 74, 81 to 84, and 91 to 94, which are cross sections of wire 40, can be observed. In FIG. 3, wire cross sections 51 to 54, 61 to 64, 71 to 74, 81 to 84, and 91 to 94, which are cross sections of wire 40, can be observed in a number corresponding to the number of windings (20 turns) of wire 40 around protrusion 24.

[0040] 3, the first layer 50, which is wound directly around the protruding portion 24 in the winding portion 42, includes four wire cross sections 51 to 54: a first layer top-level wire cross section 51, a first layer second-level wire cross section 52, a first layer third-level wire cross section 53, and a first layer fourth-level wire cross section 54. The first layer top-level wire cross section 51 is the wire cross section furthest from the plate-like portion 22 among the wire cross sections 51 to 54 included in the first layer 50. Note that the first layer 50 refers to a layer including the wire cross sections 51 to 54 that face the protruding portion 24 without sandwiching any other wire cross sections. Whether the wire 40 is formed by winding a raw wire around the protruding portion 24 to form the winding portion 42 or the wire 40 is an air-core coil, it may correspond to the first layer 50 that is wound directly around the protruding portion 24.

[0041] The first layer top wire cross section 51 includes a portion of the protrusion 24 of the first magnetic material portion 20 that is farther away from the plate-shaped portion 22 than the protrusion tip 24c, which is the farthest from the plate-shaped portion 22. That is, in FIG. 3, the first layer top wire cross section 51 has a portion that protrudes upward from a straight line L1 that passes through the protrusion tip 24c and is parallel to the plate-shaped portion upper surface 22c, which is the protrusion direction of the protrusion 24. The first layer top wire cross section 51 shown in FIG. 3 protrudes upward from the straight line L1 by about 20% of the diameter of the wire cross section in the first direction D1 away from the plate-shaped portion 22. However, the arrangement of the first layer top wire cross section 51 is not limited to the example shown in FIG. 3.

[0042] Furthermore, the coating portion 51a of the first layer top wire cross section 51 is in contact with the protruding portion 24. Because the first layer top wire cross section 51 is in contact with the protruding portion 24, it is possible to prevent the magnetic material contained in the second magnetic material portion 30 from entering the inside of the winding portion 42 from the second magnetic material portion 30 located above the winding portion 42 and the protruding portion 24. Furthermore, because the first layer top wire cross section 51 is in contact with the protruding portion 24 and protrudes upward from the straight line L1, the first layer top wire cross section 51 is suitably pressed against the protruding portion 24 during compression molding, etc., and it is possible to prevent the problem of a temporary gap being formed between the first layer top wire cross section 51 and the protruding portion 24 that would allow magnetic material powder to pass through.

[0043] 3, the protrusion tip 24c is farther from the plate-shaped portion 22 than the center 51c of the first layer's topmost wire cross section 51. That is, the proportion of the first layer's topmost wire cross section 51 that protrudes upward from the straight line L1 is less than 50% of the diameter of the wire cross section. By arranging the first layer's topmost wire cross section 51 in this manner, it is possible to reduce the possibility that the contact between the first layer's topmost wire cross section 51 and the protrusion 24 will be unintentionally released when the pressure during compression molding is increased.

[0044] 3 is arranged below (on the plate-shaped portion 22 side) the first layer top-level wire cross section 51, the first layer third-level wire cross section 53 is arranged below (on the plate-shaped portion 22 side) the first layer second-level wire cross section 52, and the first layer fourth-level wire cross section 54 is arranged below (on the plate-shaped portion 22 side) the first layer third-level wire cross section 53. Each of the layers 40-90 of the winding portion 42 of the wire 40 is made up of wire cross sections 51-54, 61-64, 71-74, 81-84, and 91-94, each of which is wound four turns around the winding shaft 40a (see FIG. 2).

[0045] 3, the second layer 60, which is wound around the protruding portion 24 on top of the first layer 50 in the winding portion 42, includes four wire cross sections 61 to 64: a second layer uppermost wire cross section 61, a second layer second-stage wire cross section 62, a second layer third-stage wire cross section 63, and a second layer fourth-stage wire cross section 64. The second layer uppermost wire cross section 61 is the wire cross section that is farthest from the plate-shaped portion 22 among the wire cross sections 61 to 64 included in the second layer 60.

[0046] The second layer uppermost wire cross section 61 of the second layer 60 is disposed closer to the plate-like portion 22 than the first layer uppermost wire cross section 51 of the first layer 50 adjacent to it on the side closer to the protrusion 24. By disposing it in this manner, it is possible to reduce the possibility that the position of the second layer uppermost wire cross section 61 will be unintentionally shifted when the pressure during compression molding is increased.

[0047] 3, the third layer 70, which is wound around the protruding portion 24 and overlaps the second layer 60 in the winding section 42, includes four wire cross sections 71-74: a third layer top-level wire cross section 71, a third layer second-level wire cross section 72, a third layer third-level wire cross section 73, and a third layer fourth-level wire cross section 74. The fourth layer 80, which is wound around the protruding portion 24 and overlaps the third layer 70 in the winding section 42, includes four wire cross sections 81-84: a fourth layer top-level wire cross section 81, a fourth layer second-level wire cross section 82, a fourth layer third-level wire cross section 83, and a fourth layer fourth-level wire cross section 84. The fifth layer 90 also includes four wire cross sections 91-94.

[0048] In the first to fourth layers 50 to 80, excluding the outermost fifth layer 90, the first to fourth layer uppermost wire cross sections 51 to 81 are arranged in a zigzag pattern. That is, the second and fourth layer uppermost wire cross sections 61, 81 are arranged closer to the plate-shaped portion 22 than the first and third layer uppermost wire cross sections 51, 71. Such a shape of the winding portion 42 is preferable from the viewpoints of preventing the wire cross sections from collapsing during compression molding and preventing the magnetic powder from moving into the interior of the winding portion 42.

[0049] 2 and 3, in the coil device 10, the thickness T1 of the second magnetic material portion 30 covering the protruding portion tip 24c along the first direction D1, which is the direction away from the plate-shaped portion 22, is preferably no more than twice the diameter R (or the average diameter if not constant) of the wire cross sections 51-54, 61-64, 71-74, 81-84, and 91-94. This makes it possible to reduce the thickness of the coil device 10 and increase the proportion of the first magnetic material portion 20 in the entire volume of the coil device 10, thereby improving the performance of the coil device 10, such as inductance.

[0050] In this way, in the coil device 10, the first layer uppermost wire cross section 51 is in contact with the protruding portion 24 and protrudes upward from the straight line L1, thereby preventing magnetic powder and the like of the second magnetic material portion 30 outside the winding portion 42 from entering the winding portion 42. This allows the coil device 10 to effectively prevent damage to the coating of the wire 40 and the resulting short circuit defects.

[0051] In the coil device 10, maintaining good adhesion between the first layer uppermost wire cross section 51 and the protruding portion 24 is particularly important from the viewpoint of preventing magnetic powder from entering the inside of the winding portion 42 from the second magnetic material portion 30. The reason for this is that, for example, the direction of pressure application during compression molding of the coil device 10 as shown in Fig. 2 is often vertical (first direction D1), which increases the distance that particles move in the first direction D1. Also, adhesion between the wire cross sections 51-54, 61-64, 71-74, 81-84, 91-94 is relatively easily maintained by the contact between the flexible coating portions 51a, and it is also possible to prevent particles from passing through by, for example, fusing the coating portions together.

[0052] In this way, the coil device 10 can prevent the second magnetic material portion 30 from moving from the outside to the inside of the winding portion 42 during compression molding, and can effectively prevent damage to the coating portion of the wire 40.

[0053] 4 is an enlarged schematic diagram of the periphery of the winding portion 142 in the coil device according to the first modified example. The coil device according to the first modified example is similar to the coil device 10 according to the first embodiment except for the shape of the winding portion 142. Regarding the coil device according to the first modified example, only the differences from the coil device 10 will be described. Note that in FIG. 4, the coil cross sections 151, 161, 171, and 181 are simply shown to show only the outer shapes, and the second magnetic material portion 30 is not shown.

[0054] As shown in Fig. 4, the winding section 142 has a first layer 150, a second layer 160, a third layer 170, and a fourth layer 180. Each of the layers 150, 160, 170, and 180 is composed of a wire cross section wound four turns. The first layer 150 is wound directly around the protruding portion 24 in the winding section 42. The first layer 150 has a first layer uppermost wire cross section 151, which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the first layer 150.

[0055] Furthermore, the second layer 160 is wound so as to overlap the outer circumferential side of the first layer 150 in the winding portion 142, and has a second layer uppermost wire cross section 161 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the second layer 160. The third layer 170 is wound so as to overlap the outer circumferential side of the second layer 160 in the winding portion 142, and has a third layer uppermost wire cross section 171 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the third layer 170. The fourth layer 180 is wound so as to overlap the outer circumferential side of the third layer 170 in the winding portion 142, and has a fourth layer uppermost wire cross section 181 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the fourth layer 180.

[0056] In the first to fourth layers 150 to 180, the first to fourth layer uppermost wire cross sections 151 to 181 are arranged in a zigzag pattern. That is, the first and third layer uppermost wire cross sections 151, 171 are arranged closer to the plate-shaped portion 22 than the second and fourth layer uppermost wire cross sections 161, 181. Such a shape of the winding portion 142 is preferable from the viewpoint of preventing misalignment of the wire cross sections 151 to 154, 171 to 174 during compression molding, etc.

[0057] In the coil device according to the present disclosure, a wire having a winding portion 142 shown in Fig. 4 can be used instead of the winding portion 42 shown in Fig. 1. In addition, the coil device according to the modified example has the same effects as the coil device 10 in terms of the points in common with the coil device 10.

[0058] 5 is an enlarged schematic diagram of the periphery of the winding portion 242 in a coil device according to a second modified example. The coil device according to the second modified example is similar to the coil device 10 according to the first embodiment except for the shape of the winding portion 242. Regarding the coil device according to the second modified example, only the differences from the coil device 10 will be described. Note that in FIG. 5, coil cross sections 251, 261, 271, and 281 are simply shown to show only the outer shapes, and the second magnetic material portion 30 is not shown.

[0059] 5, the winding portion 242 has a first layer 250, a second layer 260, a third layer 270, and a fourth layer 280. The first layer 250 and the second layer 260 are each composed of a wire cross section wound with four turns, and the third layer 270 and the fourth layer 280 are each composed of a wire cross section wound with five turns. The first layer 250 is wound directly around the protruding portion 24. The first layer 250 has a first layer uppermost wire cross section 251, which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the first layer 250.

[0060] Furthermore, the second layer 260 is wound so as to overlap the outer circumferential side of the first layer 250 in the winding portion 242, and has a second layer uppermost wire cross section 261 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the second layer 260. The third layer 270 is wound so as to overlap the outer circumferential side of the second layer 260 in the winding portion 242, and has a third layer uppermost wire cross section 271 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the third layer 270. The fourth layer 280 is wound so as to overlap the outer circumferential side of the third layer 270 in the winding portion 242, and has a fourth layer uppermost wire cross section 281 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the fourth layer 280.

[0061] In the first to fourth layers 250 to 280, the uppermost wire cross sections 251 to 281 of the first to fourth layers are inclined so as to move away from the plate-shaped portion 22 as they move away from the winding axis 40a (see FIGS. 1 and 2). This shape of the winding portion 242 makes it possible to increase the total number of turns of the winding portion 242 while preventing damage to the coating of the wire, even when using a protruding portion 24 that has a short protruding length in the first direction D1.

[0062] In the coil device according to the present disclosure, a wire having a winding portion 242 shown in Fig. 5 can be used instead of the winding portion 42 shown in Fig. 1. In addition, the coil device according to the modified example has the same effects as the coil device 10 in terms of the points in common with the coil device 10.

[0063] Fig. 6 is an enlarged schematic diagram of the periphery of the winding portion 342 in a coil device according to a third modified example. The coil device according to the third modified example is similar to the coil device 10 according to the first embodiment except for the shape of the winding portion 342. Regarding the coil device according to the third modified example, only the differences from the coil device 10 will be described. Note that Fig. 6 simply shows the outer shapes of the coil cross sections 351, 361, 371, and 381, and does not show the second magnetic material portion 30.

[0064] As shown in Fig. 6, the winding portion 342 has a first layer 350, a second layer 360, a third layer 370, and a fourth layer 380. The first layer 350 is composed of a wire cross section wound with four turns, the second layer 360 and the third layer 370 are each composed of a wire cross section wound with three turns, and the fourth layer 380 is composed of a wire cross section wound with two turns. The first layer 350 is wound directly around the protruding portion 24. The first layer 350 has a first layer uppermost wire cross section 351, which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the first layer 350.

[0065] Furthermore, the second layer 360 is wound so as to overlap the outer circumferential side of the first layer 350 in the winding portion 342, and has a second layer uppermost wire cross section 361 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the second layer 360. The third layer 370 is wound so as to overlap the outer circumferential side of the second layer 360 in the winding portion 342, and has a third layer uppermost wire cross section 371 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the third layer 370. The fourth layer 380 is wound so as to overlap the outer circumferential side of the third layer 370 in the winding portion 342, and has a fourth layer uppermost wire cross section 381 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the fourth layer 380.

[0066] In the first to fourth layers 350 to 380, the first to fourth layer uppermost wire cross sections 351 to 381 are inclined so as to approach the plate-shaped portion 22 as they move away from the winding axis 40a (see FIGS. 1 and 2). Furthermore, the first layer uppermost wire cross section 351 is the farthest from the plate-shaped portion 22 among all the wire cross sections included in the winding portion 342. Such a shape of the winding portion 342 is effective in preventing collapse of the winding and damage to the coating of the wire.

[0067] In the coil device according to the present disclosure, a wire having a winding portion 342 shown in Fig. 6 can be used instead of the winding portion 42 shown in Fig. 1. In addition, the coil device according to the modified example has the same effects as the coil device 10 in terms of the points in common with the coil device 10.

[0068] 7 is an enlarged schematic diagram of the periphery of the winding portion 442 in a coil device according to a fourth modified example. The coil device according to the fourth modified example is similar to the coil device 10 according to the first embodiment except for the shape of the winding portion 442. Regarding the coil device according to the fourth modified example, only the differences from the coil device 10 will be described. Note that in FIG. 7, coil cross sections 451, 461, 471, and 481 are simply shown to show only the outer shapes, and the second magnetic material portion 30 is not shown.

[0069] 7, the winding portion 442 has a first layer 450, a second layer 460, a third layer 470, and a fourth layer 480. The first layer 450, the second layer 460, and the third layer 470 are each composed of a wire cross section wound with four turns, and the fourth layer 480 is composed of a wire cross section wound with three turns. The first layer 450 is wound directly around the protruding portion 24. The first layer 450 has a first layer uppermost wire cross section 451, which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the first layer 450.

[0070] Furthermore, the second layer 460 is wound so as to overlap the outer circumferential side of the first layer 450 in the winding portion 442, and has a second layer uppermost wire cross section 461 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the second layer 460. The third layer 470 is wound so as to overlap the outer circumferential side of the second layer 460 in the winding portion 442, and has a third layer uppermost wire cross section 471 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the third layer 470. The fourth layer 480 is wound so as to overlap the outer circumferential side of the third layer 470 in the winding portion 442, and has a fourth layer uppermost wire cross section 481 which is the wire cross section farthest from the plate-shaped portion 22 among the wire cross sections included in the fourth layer 480.

[0071] The second layer uppermost wire cross section 461 of the second layer 460 is disposed so as to be farther away from the plate-shaped portion 22 than the first layer uppermost wire cross section 451 of the first layer 450. In the second to fourth layers 460 to 480, the second to fourth layer uppermost wire cross sections 461, 471, 481 are disposed so as to be inclined so as to approach the plate-shaped portion 22 as they are farther away from the winding axis 40a (see FIGS. 1 and 2). Such a shape of the winding portion 342 has the effect of increasing the number of windings while preventing the winding from becoming unbalanced.

[0072] In the coil device according to the present disclosure, a wire having a winding portion 442 shown in Fig. 7 can be used instead of the winding portion 42 shown in Fig. 1. In addition, the coil device according to the modified example has the same effects as the coil device 10 in terms of the points in common with the coil device 10.

[0073] FIG. 8 is an enlarged schematic diagram of the periphery of the winding portion 542 in a coil device according to a fifth modified example. The coil device according to the fifth modified example is similar to the coil device 10 according to the first embodiment, except for the shape of the winding portion 542 and the shape of the protrusion 524 of the first magnetic material portion 520. Regarding the coil device according to the fifth modified example, only the differences from the coil device 10 will be described. Note that FIG. 8 shows only the first layer 550 of the winding portion 542. Furthermore, the coil cross sections 551 to 554 simply show only the outer shapes, and the second magnetic material portion 30 is not shown.

[0074] 8, a step surface 524ab is formed at a connection portion between the protrusion side surface 524a and the protrusion tip 524c of the protrusion 524 in the first magnetic material portion 520. A first layer uppermost wire cross section 551, which is the wire cross section farthest from the plate-shaped portion 22 among the first layer 550 of the winding portion 542, is provided on the step surface 524ab.

[0075] First layer uppermost wire cross section 551 is disposed at a position closest to winding axis 40a (see FIGS. 1 and 2) among wire cross sections 551, 552, 553, and 554 included in first layer 550. Such a shape of winding portion 542 can suitably prevent the problem of first layer uppermost wire cross section 551 becoming misaligned during compression molding, etc.

[0076] In the coil device according to the present disclosure, a wire having a winding portion 542 shown in Fig. 8 can be used instead of the winding portion 42 shown in Fig. 1. In addition, the coil device according to the modified example has the same effects as the coil device 10 in terms of the points in common with the coil device 10.

[0077] FIG. 9 is an enlarged schematic diagram of the periphery of a winding portion 642 in a coil device according to a sixth modified example. The coil device according to the sixth modified example is similar to the coil device 10 according to the first embodiment, except for the shape of the winding portion 642 and the shape of the protrusion 624 of the first magnetic material portion 620. Regarding the coil device according to the sixth modified example, only the differences from the coil device 10 will be described. Note that FIG. 9 shows only the first layer 650 of the winding portion 642. Furthermore, the coil cross sections 651 to 654 simply show only the outer shapes, and the second magnetic material portion 30 is not shown.

[0078] 8, in first magnetic material portion 620, protrusion 624 has protrusion side surface 624a surrounding winding axis 40a (see FIGS. 1 and 2), which is inclined toward winding axis 40a as it moves away from plate-shaped portion 22 and approaches protrusion tip 624c. Wire cross sections 651, 652, 653, and 654 included in first layer 650 are arranged along the inclination of protrusion side surface 624a.

[0079] The first layer uppermost wire cross section 651 is disposed at a position closest to the winding axis 40a (see FIGS. 1 and 2) among the wire cross sections 651 to 654 included in the first layer 650. Such a shape of the winding portion 642 can suitably prevent the problem of the first layer uppermost wire cross section 651 being misaligned during compression molding, etc.

[0080] In the coil device according to the present disclosure, a wire having a winding portion 542 shown in Fig. 8 can be used instead of the winding portion 42 shown in Fig. 1. In addition, the coil device according to the modified example has the same effects as the coil device 10 in terms of the commonalities with the coil device 10. Furthermore, the present disclosure is not limited to the above-described embodiments and examples, and various modifications can be made within the scope of the present disclosure.

[0081] 10(a) to 10(c), the contact state of the first layer uppermost wire cross sections 751 to 951 with the protrusion 24 is not limited to those shown in the embodiments and modifications. The first layer uppermost wire cross section 751 shown in Fig. 10(a) has a center 751c positioned on a straight line L1 that passes through the protrusion tip 24c and is parallel to the plate-shaped portion upper surface 22c.

[0082] 10(b), the center 851c of the first layer uppermost wire cross section 851 is located above the line L1 that passes through the protrusion tip 24c and is parallel to the plate-shaped portion upper surface 22c. Also, the center 951c of the first layer uppermost wire cross section 951 shown in FIG. 10(c) is located on an extension of the protrusion side surface 24a. Arranging the first layer uppermost wire cross sections 751, 851, 951 in the positions shown in FIGS. 10(a) to 10(c) has the effect of making it difficult for particles to flow along the upper arc portions of the first layer uppermost wire cross sections 751, 851, 951 toward the area between the protrusion side surface 24a and the first layer uppermost wire cross sections 751, 851, 951. [Explanation of symbols]

[0083] 10...Coil device 20, 520, 620...first magnetic material part 22...Plate-shaped part 22a...Side surface of plate-shaped part 22b...Bottom surface of plate-shaped portion 22c...Top surface of plate-shaped part 24, 524, 624...protrusion 524ab…step surface 24a, 524a, 624a...Protrusion side 24c, 524c, 624c...tip of protrusion 30…Second magnetic material part 40...wire 40a...winding shaft 41...Wire end 42, 142, 242, 342, 442, 542, 642...winding section 91, 92, 93, 94, 552, 553, 554, 652, 653, 654...Wire cross section 50, 150, 250, 350, 450, 550, 650…1st layer 51, 251, 351, 451, 551, 651, 751, 851, 951...Cross section of the top wire of the first layer 52...1st layer 2nd stage wire cross section 53...1st layer 3rd stage wire cross section 54...1st layer, 4th stage wire cross section 60, 260, 260, 360, 460…2nd layer 61, 161, 261, 361, 461...Second layer top wire cross section 62...Second layer, second stage wire cross section 63...Second layer, third stage wire cross section 64...Second layer, fourth stage wire cross section 70, 170, 270, 370, 470…Third layer 71, 171, 271, 371, 471...Cross section of the top wire of the third layer 72...3rd layer, 2nd stage wire cross section 73...3rd layer, 3rd stage wire cross section 74...3rd layer, 4th stage wire cross section 80, 180, 280, 380, 480…4th layer 81, 181, 281, 381, 481...4th layer top wire cross section 82...4th layer, 2nd stage wire cross section 83...4th layer, 3rd stage wire cross section 84...4th layer, 4th stage wire cross section 751c, 851c, 951c...center 90…5th layer D1… 1st direction D2…Second direction

Claims

1. a first magnetic material portion containing a magnetic substance and having a plate-shaped portion and a protruding portion protruding from the plate-shaped portion; a wire having a conductor portion and an insulating covering portion covering the conductor portion, the wire having a winding portion forming a winding layer that winds around the protrusion; a second magnetic material portion containing a magnetic substance and a resin and covering at least the winding portion and the protruding portion of the first magnetic material portion; In a predetermined cross section including the winding axis of the winding section where a wire cross section, which is a cross section of the wire, is observed, the topmost wire cross section of the first layer, which is included in the first layer that is directly wound around the protrusion in the winding section and is furthest from the plate-shaped portion, includes a portion that is further away from the plate-shaped portion than the tip of the protrusion that is furthest from the plate-shaped portion, and the coating portion in the topmost wire cross section of the first layer is in contact with the protrusion.

2. The coil device according to claim 1 , wherein the tip of the protrusion is spaced farther from the plate-shaped portion than the center of the cross section of the topmost wire of the first layer.

3. The coil device according to claim 1, wherein the second layer, which is wound around the protruding portion on top of the first layer in the winding section, has a topmost wire cross section of the second layer that is furthest from the plate-shaped portion, and is closer to the plate-shaped portion than the topmost wire cross section of the first layer.

4. The coil device according to claim 1 , wherein the first layer uppermost wire cross section is the furthest from the plate-shaped portion among all the wire cross sections included in the winding portion.

5. The coil device according to claim 1 , wherein the uppermost wire cross section of the first layer is the closest to the winding axis among the wire cross sections included in the first layer.

6. 2. The coil device according to claim 1, wherein a side surface of the protrusion surrounding the winding axis is inclined so as to approach the winding axis as it moves away from the plate-shaped portion, and the wire cross section included in the first layer is arranged along the inclination of the side surface of the protrusion.

7. The coil device according to claim 1 , wherein the thickness of the second magnetic material portion covering the tip of the protrusion in a direction away from the plate-shaped portion is equal to or less than twice the average diameter of the wire cross section.

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