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 having a plate-shaped part and a protruding part protruding from the plate-shaped portion; a wire having a winding part forming a winding layer around which the protruding part is wound; and a second magnetic material part containing a magnetic material and a resin and covering at least the winding part and the protruding part. In a predetermined cross section including a winding axis, a first average gap width, which is an average gap width of a first layer directly wound around the protruding part, is wider than a second average gap width of a second layer wound around the protruding part overlapping a first layer in the winding part. The first layer protruding part gap width, which is a gap in a second direction between the first layer and the protruding part of a first layer uppermost wire cross section, is narrower than the first average gap width.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 containing a magnetic substance and a resin and covering at least the winding portion and the protruding portion; In a predetermined cross section including the winding axis of the winding section where a wire cross section that is a cross section of the wire is observed, a first average gap width that is an average gap width along a first direction away from the plate-shaped portion between the wire cross sections included in a first layer that is directly wound around the protruding portion in the winding section is wider than a second average gap width that is an average gap width along the first direction between the wire cross sections included in a second layer that is wound around the protruding portion and overlaps the first layer in the winding section, A first layer protruding portion gap width, which is the gap width along a second direction perpendicular to the winding axis between the protruding portion and the topmost wire cross section of the first layer that is farthest from the plate-shaped portion among the wire cross sections included in the first layer, is narrower than the first average gap width.

[0007] In the coil device according to the present disclosure, the first average gap width is wider than the second average gap width, so that the first layer is effectively pressed against the protruding portion by the second layer. This coil device can prevent particles of the second magnetic material portion from entering the interior of the winding portion, thereby effectively preventing damage to the wire and the resulting short circuit. Furthermore, narrowing the gap width between the first layer and the protruding portion can prevent particles of the second magnetic material portion from entering the interior of the winding portion. Furthermore, narrowing the second average gap width can compactly arrange the winding portion, improving the magnetic characteristics of the coil device.

[0008] Also, for example, the first layer upper gap width, which is the gap width along the first direction between the first layer top wire cross section and the first layer second wire cross section adjacent to the first layer top wire cross section in the first direction, may be narrower than the first average gap width.

[0009] By narrowing the gap width at the top of the first layer, it is possible to prevent the top wire cross section of the first layer from shifting position during compression molding, and to prevent the problem of the coating layer of the top wire cross section of the first layer itself being damaged.

[0010] Also, for example, the first layer upper gap width along the first direction between the first layer top wire cross section and the first layer second wire cross section adjacent to the first layer top wire cross section in the first direction may be wider than the first average gap width.

[0011] In such a coil device, the uppermost wire cross section of the first layer is effectively pressed against the protrusion by the wire cross section of the second layer, thereby preventing particles 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 include a portion of the protruding portion that is farther away from the plate-shaped portion than the tip of the protruding portion that is farthest from the plate-shaped portion.

[0013] A coil device having such a winding portion can prevent particles of the second magnetic material portion from entering the interior of the winding portion because the top wire cross section of the first layer is effectively pressed toward the protrusion by the wire cross section of the second layer.

[0014] Furthermore, for example, the second layer uppermost wire cross section, which is the wire cross section included in the second layer and is farthest from the plate-shaped portion, may be closer to the plate-shaped portion than the first layer uppermost wire cross section.

[0015] 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.

[0016] Furthermore, for example, the distance along the first direction between the first layer's bottommost wire cross section, which is closest to the plate-like portion among the wire cross sections included in the first layer, and the first layer's topmost wire cross section may be longer than the distance along the first direction between the second layer's bottommost wire cross section, which is closest to the plate-like portion among the wire cross sections included in the second layer, and the second layer's topmost wire cross section, which is farthest from the plate-like portion among the wire cross sections included in the second layer.

[0017] This coil device prevents particles of the second magnetic material from entering the winding, effectively preventing damage to the wire and the resulting short circuit. In addition, by arranging the entire second layer at a short distance, the winding can be made compact, improving the magnetic properties of the coil device. [Brief explanation of the drawings]

[0018] [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 a conceptual diagram showing the definition of the gap width regarding the first layer and the second layer in the winding portion shown in FIG. [Figure 5] FIG. 5 is a conceptual diagram illustrating the shape of the first layer according to the first and second modified examples. [Figure 6] FIG. 6 is a conceptual diagram illustrating the shape of the first layer according to the third and fourth modifications. [Figure 7] FIG. 7 is a conceptual diagram illustrating the shape of the first layer according to the fifth and sixth modifications. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the contents shown in the drawings are merely schematic and illustrative for understanding 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. 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.).

[0026] 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, polyester-nylon, etc.

[0027] 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 Fig. 2, 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 wound around protruding portion 24. Note that, although wire 40 is wound around protruding portion 24 20 times in coil device 10 shown in Figs. 2 and 3, the number of turns of winding portion 42 is not particularly limited.

[0028] 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.

[0029] 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 is close to or in contact with the protruding portion 24, or the first to fifth layers 50-90 are close to or in contact with 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 being 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.

[0030] 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.

[0031] 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.

[0032] 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 in close contact with the winding portion 42 from the outer circumferential side and the upper side.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 uppermost wire cross section 51, a first layer second-stage wire cross section 52, a first layer third-stage wire cross section 53, and a first layer fourth-stage wire cross section 54. The first layer uppermost wire cross section 51 is the wire cross section that is farthest from the plate-shaped portion 22 among the wire cross sections 51 to 54 included in the first layer 50. The first layer fourth-stage wire cross section 54 corresponds to the first layer lower-stage wire cross section that is closest to the plate-shaped portion 22 among the wire cross sections 51 to 54 included in the first layer 50. The first layer 50 means a layer including wire cross sections 51 to 54 that face the protrusion 24 without any other wire cross sections in between, and may correspond to the first layer 50 that is wound directly around the protrusion 24 whether the wire 40 is formed by winding raw wire around the protrusion 24 to form the winding section 42, or whether the wire 40 is an air-core coil.

[0039] 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.

[0040] Furthermore, it is preferable that the covering portion 51a of the first layer top wire cross section 51 be in contact with the protrusion 24 or that there is a narrow gap between the covering portion 51a and the protrusion 24. By having the first layer top wire cross section 51 be in contact with or very close to the protrusion 24, it is possible to prevent the magnetic material contained in the second magnetic material portion 30 from entering the interior of the winding portion 42 from the second magnetic material portion 30 located above the winding portion 42 and the protrusion 24. Furthermore, by having the first layer top wire cross section 51 be in contact with the protrusion 24 and extending upward from the straight line L1, the first layer top wire cross section 51 is suitably pressed against the protrusion 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 protrusion 24 that would allow magnetic material powder to pass through.

[0041] 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.

[0042] 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).

[0043] 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. The second layer fourth-stage wire cross section 64 is the wire cross section that is closest to the plate-shaped portion 22 among the wire cross sections 61 to 64 included in the second layer 60, and corresponds to the second layer lowermost wire cross section.

[0044] 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.

[0045] 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.

[0046] 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. This shape of the winding portion 42 is preferable from the viewpoints of preventing misalignment of the wire cross sections 71 to 74 during compression molding and preventing the migration of magnetic powder into the interior of the winding portion 42.

[0047] 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.

[0048] In this way, in the coil device 10, the first layer uppermost wire cross section 51 is in contact with or close to 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.

[0049] Fig. 4 is a conceptual diagram for explaining the distance and gap width related to the first layer 50 and the second layer 60 in the winding portion 42 shown in Fig. 3. Fig. 4 shows only the wire cross sections 51-54 of the first layer 50, the wire cross sections 61-64 of the second layer 60, and the protruding portion 24 and the plate-shaped portion 22 of the first magnetic material portion 20.

[0050] In the coil device 10, a first average gap width G01, which is the average spacing along the first direction D1 between the wire cross sections 51 to 54 included in the first layer 50, is wider than a second average gap width G02, which is the average spacing along the first direction D1 between the wire cross sections 61 to 64 included in the second layer 60. As shown in FIG. 4 , if the gap along the first direction D1 between the first layer top-level wire cross section 51 and the first layer second-level wire cross section 52 is defined as g11, the gap along the first direction D1 between the first layer second-level wire cross section 52 and the first layer third-level wire cross section 53 is defined as g12, and the gap along the first direction D1 between the first layer third-level wire cross section 53 and the first layer fourth-level wire cross section 54 is defined as g13, the first average gap width G01 is the average value of these gaps g11, g12, and g13.

[0051] Furthermore, if the gap along the first direction D1 between the second layer top-stage wire cross section 61 and the second layer second-stage wire cross section 62 is g21, the gap along the first direction D1 between the second layer second-stage wire cross section 62 and the second layer third-stage wire cross section 63 is g22, and the gap along the first direction D1 between the second layer third-stage wire cross section 63 and the second layer fourth-stage wire cross section 64 is g23, the second average gap width G02 is the average value of these gaps g21, g22, and g23.

[0052] 4, by making the first average gap width G01 wider than the second average gap width G02, the wire cross sections 61-64 of the second layer 60 can easily fit into the undulations on the outer periphery of the first layer 50 during compression molding, increasing the force pressing the wire cross sections 51-54 of the first layer against the protrusion 24. This coil device 10 can prevent the second magnetic material portion 30 from moving from the outside to the inside of the winding portion 42, and can effectively prevent damage to the coating of the wire 40.

[0053] 4, in the coil device 10, the first layer protrusion gap width G12, which is the gap width along the second direction D2 between the first layer uppermost wire cross section 51 and the protrusion 24, is narrower than the first average gap width G01. By narrowing the first layer protrusion gap width G12, it is possible to appropriately prevent the problem of magnetic material moving into the winding portion 42 and damaging the coating of the wire 40.

[0054] 4, the first layer upper gap width G11, which is the gap width along the first direction D1 between the first layer uppermost wire cross section 51 and the first layer second-stage wire cross section 52 adjacent to the first layer uppermost wire cross section 51 in the first direction D1, is narrower than the first average gap width G01. Note that the first layer upper gap width G11 is the same as the gap g11 defined in the description of the first average gap width G01. By narrowing the first layer upper gap width G11, it is possible to suppress displacement of the first layer uppermost wire cross section 51 during compression molding, and to prevent damage to the coating portion 51a of the first layer uppermost wire cross section 51 itself.

[0055] Furthermore, in the coil device 10, the first layer vertical distance L01, which is the distance along the first direction D1 between the first layer fourth-stage wire cross section 54, which is the bottommost wire cross section of the first layer, and the first layer top-stage wire cross section 51, is longer than the second layer vertical distance L02, which is the distance along the first direction D1 between the second layer fourth-stage wire cross section 64, which is the bottommost wire cross section of the second layer, and the second layer top-stage wire cross section 61. In this coil device 10, the entire second layer 60 is arranged within a short distance in the first direction D1, allowing the winding section 42 to be formed compactly and improving the magnetic characteristics of the coil device. This is because making the winding section 42 compact allows the volume proportions of the second magnetic material portion 30 and the first magnetic material portion 20 in the coil device 10 to be increased. Note that the first layer vertical distance L01 is determined based on the centers 51c, 54c, 61c, and 64c of the wire cross sections 51, 54, 61, and 64.

[0056] In the coil device 10, it is particularly important that the gap between the first layer uppermost wire cross section 51 and the protruding portion 24 is narrow in order to prevent 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 pressure direction during compression molding of the coil device 10 as shown in Fig. 2 is often the vertical direction (first direction D1), which increases the distance that particles move in the first direction D1. Also, the 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.

[0057] 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 suitably prevent damage to the coating portion of the wire 40.

[0058] While the present disclosure has been described above using embodiments, the technical scope of the present disclosure is not limited to the above-described embodiments, and other modifications and embodiments are naturally included in the present disclosure. For example, Figures 5 to 7 are conceptual diagrams showing modifications of the arrangement of coil cross sections 51 to 54 included in the first layer 50. Note that in Figures 5 to 7, only the outer shapes of the coil cross sections 51 to 54 are simply shown.

[0059] 5(a), in the first layer 50 according to the first modified example, a gap g11 along the first direction D1 between the first layer top-level wire cross section 51 and the first layer second-level wire cross section 52 is equal to a gap g12 along the first direction D1 between the first layer second-level wire cross section 52 and the first layer third-level wire cross section 53. Furthermore, these gaps g11 and g12 are narrower than a gap g13 along the first direction D1 between the first layer third-level wire cross section 53 and the first layer fourth-level wire cross section 54.

[0060] 5(b), the gaps g11, g12, and g13 become narrower as the distance from the plate-like portion 22 (see FIGS. 1 to 4) increases, i.e., as the distance increases upward. In the first layer 50 according to the first and second modifications, the positional deviation of the uppermost wire cross section 51 of the first layer can be suitably prevented.

[0061] 6(a), in the first layer 50 according to the third modified example, the gap g12 along the first direction D1 between the first layer second-stage wire cross section 52 and the first layer third-stage wire cross section 53 is equal to the gap g13 along the first direction D1 between the first layer third-stage wire cross section 53 and the first layer fourth-stage wire cross section 54. Furthermore, these gaps g12 and g13 are narrower than the gap g11 along the first direction D1 between the first layer top-stage wire cross section 51 and the first layer second-stage wire cross section 52.

[0062] In addition, in the first layer 50 according to the fourth modified example shown in FIG. 6(b), the gaps g11, g12, and g13 become wider as the distance from the plate-like portion 22 (see FIGS. 1 to 4) increases, i.e., as the distance increases upward. In the first layer 50 according to the third and fourth modified examples, the first layer upper gap width G11 (same as g11), which is the gap width along the first direction D1 between the first layer uppermost wire cross section 51 and the first layer second-stage wire cross section, is wider than the first average gap width G01 (see FIG. 4). In the first layer 50 according to the third and fourth modified examples, a force pressing the first layer uppermost wire cross section 51 against the protrusion 24 can be effectively obtained.

[0063] 7(a), in the first layer 50 according to the fifth modified example, a gap g11 between the first layer top-stage wire cross section 51 and the first layer second-stage wire cross section 52 along the first direction D1 is equal to a gap g13 between the first layer third-stage wire cross section 53 and the first layer fourth-stage wire cross section 54 along the first direction D1. Furthermore, these gaps g11 and g13 are narrower than a gap g12 between the first layer second-stage wire cross section 52 and the first layer third-stage wire cross section 53 along the first direction D1.

[0064] 7(b), the gaps g11, g12, and g13 are substantially the same for the first layer 50 according to the sixth modified example. The first layer 50 according to each modified example may be used in place of the first layer 50 according to the embodiment.

[0065] As shown in Figures 3 and 4, the first average gap width G01, the second average gap width G02, the first layer upper gap width G11, and the first layer protruding portion gap width G12 were calculated based on the outline shape of the wire cross sections 51 to 54, 61 to 64. However, if the wire is a solid wire, the first average gap width G01, the second average gap width G02, the first layer upper gap width G11, and the first layer protruding portion gap width G12 may be determined based on the outline shape of only the conductor portion of the wire 40, assuming that there is no coating portion, and there is no problem as long as a uniform standard is used. [Explanation of symbols]

[0066] 10...Coil device 20...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...Protrusion 24a…Protrusion side surface 24c…Tip of protrusion 30…Second magnetic material part 40...wire 40a...winding shaft 41...Wire end 42...Winding section 51~54, 61~64, 71~74, 81~84, 91~94...Wire cross section 50…1st layer 51...First layer top wire cross section 51a...coating part 51b...conductor part 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…Second layer 61...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…Third layer 71...3rd layer top wire cross section 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…4th layer 81...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 51c, 54c, 61c, 64c...center 90…5th layer D1…first direction D2…Second direction G01...First average gap width G12: First layer protrusion gap width G11: First layer upper gap width L01…1st layer vertical distance G02: Second average gap width L02…2nd layer vertical distance g11, g12, g13, g21, g22, g23...gaps

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; In a predetermined cross section including the winding axis of the winding portion where a wire cross section that is a cross section of the wire is observed, a first average gap width that is an average gap width along a first direction away from the plate-shaped portion between the wire cross sections included in a first layer that is directly wound around the protruding portion in the winding portion is wider than a second average gap width that is an average gap width along the first direction between the wire cross sections included in a second layer that is wound around the protruding portion and overlaps the first layer in the winding portion, A coil device in which the first layer protrusion gap width, which is the gap width along a second direction perpendicular to the winding axis between the protrusion and the topmost wire cross section of the first layer that is farthest from the plate-shaped portion among the wire cross sections included in the first layer, is narrower than the first average gap width.

2. The coil device of claim 1, wherein the first layer upper gap width, which is the gap width along the first direction between the first layer top wire section and the first layer second wire section adjacent to the first layer top wire section in the first direction, is narrower than the first average gap width.

3. The coil device of claim 1, wherein the first layer upper gap width along the first direction between the first layer top wire section and the first layer second wire section adjacent to the first layer top wire section in the first direction is wider than the first average gap width.

4. The coil device according to claim 1 , wherein the first layer uppermost wire cross section includes a portion of the protrusion that is farther away from the plate-shaped portion than the tip of the protrusion that is farthest from the plate-shaped portion.

5. The coil device according to claim 1, wherein the second layer's topmost wire cross section, which is the wire cross section included in the second layer and is furthest from the plate-shaped portion, is closer to the plate-shaped portion than the first layer's topmost wire cross section.

6. 2. The coil device of claim 1, wherein the distance along the first direction between the bottommost wire cross section of the first layer, which is closest to the plate-like portion among the wire cross sections included in the first layer, and the topmost wire cross section of the first layer, is longer than the distance along the first direction between the bottommost wire cross section of the second layer, which is closest to the plate-like portion among the wire cross sections included in the second layer, and the topmost wire cross section of the second layer, which is farthest from the plate-like portion among the wire cross sections included in the second layer.

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