Coil component

Abstract

To provide a coil component capable of suppressing the heat generated by wires that configure a winding.SOLUTION: A coil component 1 includes a first bobbin 10 having a first cylinder 10a, a first winding 30 wound around the first cylinder 10a, and a core 2 inserted into the first cylinder 10a and having a gap 2c at a location in the first cylinder 10a. The first bobbin 10 has a wall portion 10b that protrudes from the outer surface of the first cylinder 10a at a location overlapping the gap 2c in the radial direction of the first cylinder 10a. The first winding 30 is wound on both sides in the axial direction of the wall portion 10b in the first cylinder 10a.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a coil component.

Background Art

[0002] Patent Document 1 discloses a coil component in which a core is inserted inside a cylindrical bobbin and a winding is wound around the outside of the bobbin.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, among coil components, in order to obtain an exciting inductance, there is one in which a core is axially divided inside a bobbin to form a gap in the core. In this type of coil component, eddy current loss occurs in a portion of the wire material constituting the winding that overlaps the gap of the core in the radial direction due to the leakage magnetic flux generated in the gap of the core. For this reason, there is a problem that the wire portion overlapping the gap of the core is likely to locally generate heat.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a coil component capable of suppressing heat generation of a wire material constituting a winding.

Means for Solving the Problems

[0006] One aspect of the present invention includes a bobbin having a cylindrical portion, a winding wound around the cylindrical portion, and a core inserted through the cylindrical portion and having a gap at a position inside the cylindrical portion. The bobbin has a wall portion protruding from an outer peripheral surface of the cylindrical portion at a position overlapping the gap in a radial direction of the cylindrical portion, and the winding is wound around both axial sides of the wall portion in the cylindrical portion. The bobbin includes two bobbin components that are connected to each other in the axial direction, and the wall portion is provided only on one of the bobbin components. It is a coil component.

Advantages of the Invention

[0007] In the coil component of the present invention, the bobbin has a wall portion protruding from the outer peripheral surface of the cylindrical portion at a position overlapping the gap in the radial direction of the cylindrical portion. The winding is wound around both axial sides of the wall portion in the cylindrical portion. Thereby, it is possible to suppress at least a part of the winding from overlapping the gap in the radial direction. For this reason, compared with the case where the winding is wound around the outer side in the radial direction of the gap, the region of the winding through which the leakage magnetic flux generated in the gap passes can be narrowed. Therefore, since the eddy current loss generated by the leakage magnetic flux passing through the wire can be suppressed, the heat generation of the wire can be suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0009] 〔First Embodiment〕 Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIGS. 3 to 5 schematically show each component of the coil component 1 according to the present invention. In this embodiment, the coil component 1 is applied to a transformer. As shown in FIGS. 1 and 2, the coil component 1 includes a first bobbin 10 (corresponding to the "bobbin" in the claims), a second bobbin 20, a first winding 30, a first winding 30, a second winding 40, a cover component 3, a core 2, and a terminal block 8. The coil component 1 obtains the function of a resonance coil by utilizing the leakage inductance generated between the first winding 30 and the second winding 40.

[0010] As shown in FIGS. 2 and 3, the first bobbin 10 is made of a material having electrical insulation properties such as hard plastic. The first bobbin 10 has a cylindrical first cylindrical portion 10a (corresponding to the "cylindrical portion" in the claims), a wall portion 10b disposed in the middle of the first cylindrical portion 10a in the axial direction, and a first flange portion 10c disposed at one end of the first cylindrical portion 10a in the axial direction. The wall portion 10b and the first flange portion 10c each project radially outward from the entire circumferential direction of the outer peripheral surface of the first cylindrical portion 10a. Hereinafter, the axial direction of the first cylindrical portion 10a will be simply referred to as the "axial direction", the radial direction of the first cylindrical portion 10a will be simply referred to as the "radial direction", and the circumferential direction of the first cylindrical portion 10a will be simply referred to as the "circumferential direction".

[0011] As shown in FIGS. 2 to 4, the width of the wall portion 10b in the axial direction is larger than the wire diameter of the wire forming the first winding 30 and the second winding 40 described later. Two guide passages 10b1, 10b2 (first guide passage 10b1, second guide passage 10b2) through which the wire of the first winding 30 passes through the wall portion 10b in the axial direction are formed at intervals in the circumferential direction. The two guide passages 10b1, 10b2 open to the outer peripheral edge side of the wall portion 10b in the radial direction. The first guide passage 10b1 is inclined in the circumferential direction with respect to the axial direction. The second guide passage 10b2 is orthogonal to the circumferential direction. The outer edge of the first flange portion 10c is located radially outside the outer edge of the wall portion 10b when viewed from the axial direction. The distance from the wall portion 10b to the first flange portion 10c in the axial direction is longer than the distance from the wall portion 10b to the other end of the first cylindrical portion 10a on the side opposite to the first flange portion 10c in the axial direction.

[0012] As shown in FIGS. 3 and 5, the first bobbin 10 is composed of two bobbin components 11 and 12 (the first bobbin component 11 and the second bobbin component 12) that are arranged axially and connected to each other. The first bobbin component 11 has a wall portion 10b and an overlapping portion 10a1 that is arranged on the opposite side of the first flange portion 10c in the axial direction with respect to the wall portion 10b among the first cylindrical portions 10a. A concave portion 13 that is recessed radially outward is formed in a portion of the inner peripheral surface of the overlapping portion 10a1 that corresponds to the wall portion 10b. The concave portion 13 is formed in an annular shape along the circumferential direction.

[0013] The second bobbin component 12 has a first flange portion 10c and a non-overlapping portion 10a2 that is arranged on the first flange portion 10c side in the axial direction with respect to the wall portion 10b among the first cylindrical portions 10a. The outer diameter dimension of the non-overlapping portion 10a2 is smaller than the outer diameter dimension of the overlapping portion 10a1. The outer diameter dimension of the non-overlapping portion 10a2 is equal to the inner diameter dimension of the portion of the overlapping portion 10a1 in the formation portion of the concave portion 13. The inner diameter dimension of the non-overlapping portion 10a2 is equal to the inner diameter dimension of the portion of the overlapping portion 10a1 excluding the formation portion of the concave portion 13. One end portion of the second bobbin component 12 on the first bobbin component 11 side in the non-overlapping portion 10a2 is inserted inside the concave portion 13. Thereby, the second bobbin component 12 is connected to the first bobbin component 11. In a state where the first bobbin component 11 and the second bobbin component 12 are connected, the inner peripheral surface of the overlapping portion 10a1 of the first bobbin component 11 and the inner peripheral surface of the non-overlapping portion 10a2 of the second bobbin component 12 are flush. Note that the outer diameter dimension of the non-overlapping portion 10a2 may be equal to the outer diameter dimension of the overlapping portion 10a1 or may be larger than the outer diameter dimension of the overlapping portion 10a1. Further, in the first bobbin 10, the inner diameter dimensions of the overlapping portion 10a1 and the non-overlapping portion 10a2 may be different from each other, and the inner peripheral surface of the overlapping portion 10a1 and the inner peripheral surface of the non-overlapping portion 10a2 may be connected in a stepped manner.

[0014] The second bobbin 20 is made of a material having electrical insulation properties such as hard plastic. The second bobbin 20 has a cylindrical second cylindrical portion 20a and a second flange portion 20b disposed at one axial end of the second cylindrical portion 20a. The second flange portion 20b protrudes radially outward from the entire circumferential direction of the outer peripheral surface of the second cylindrical portion 20a. The inner diameter dimension of the second cylindrical portion 20a is larger than the outer diameter dimension of the wall portion 10b of the first bobbin 10. The first bobbin structure 11 of the first bobbin 10 is inserted inside the second cylindrical portion 20a. Both ends of the second cylindrical portion 20a in the axial direction are located inside the first bobbin structure 11 in the axial direction. Note that, as shown in FIG. 3, the second flange portion 20b may be provided at both axial ends of the second cylindrical portion 20a.

[0015] The first winding 30 is formed in a cylindrical shape by being wound around the outer peripheral surface of the first cylindrical portion 10a. The wire material of the first winding 30 is a litz wire in which a plurality of enameled wires are twisted together. The first winding 30 is an input-side primary winding connected to a power circuit (not shown). The first winding 30 is configured by winding the wire material around the outer peripheral surface of the first cylindrical portion 10a in two layers on both sides of the wall portion 10b of the first bobbin 10 in the axial direction. That is, the first winding 30 is wound in two layers each on the outer peripheral surface of the overlapping portion 10a1 of the first cylindrical portion 10a and the outer peripheral surface of the non-overlapping portion 10a2 of the first cylindrical portion 10a. In the following description, the portion of the first winding 30 wound around the overlapping portion 10a1 is referred to as the overlapping winding 31, and the portion wound around the non-overlapping portion 10a2 is referred to as the non-overlapping winding 32. The axial length of the non-overlapping winding 32 is longer than the axial length of the overlapping winding 31.

[0016] Here, with reference to FIGS. 2 and 3, an example of the winding method of the first winding 30 will be described. To wind the first winding 30 around the first cylindrical portion 10a, first, a wire is wound around the outer peripheral surface from the end on the wall portion 10b side in the axial direction of the overlapping portion 10a1 to the end on the side opposite to the wall portion 10b side in the axial direction of the overlapping portion 10a1 to form an overlapping winding 31. Subsequently, one end 30a of the wire of the first winding 30 is drawn out from the non-overlapping portion 10a2 side through the first guide passage 10b1 (see FIG. 5). Also, a wire is linearly extended in the axial direction from the end on the wall portion 10b side in the axial direction of the overlapping portion 10a1 through the second guide passage 10b2 to the end on the side opposite to the first flange portion 10c of the non-overlapping portion 10a2. Subsequently, a wire is wound around the outer peripheral surface of the non-overlapping portion 10a2 to form a non-overlapping winding 32. Finally, the other end 30a of the wire of the first winding 30 is drawn out from the non-overlapping portion 10a2 (see FIG. 5) side, thereby completing the winding method of the first winding 30. Note that the number of layers of the first winding 30 wound around the first cylindrical portion 10a may be one layer or three or more layers. Also, the number of layers of the overlapping winding 31 and the non-overlapping winding 32 in the first winding 30 may be different. The winding method of the first winding 30 is not limited to the above-described example, and a winding method as shown in the schematic diagram of FIG. 4 may be adopted.

[0017] As shown in FIG. 2, the second winding 40 is formed in a cylindrical shape by being wound around the outer peripheral surface of the second cylindrical portion 20a. The wire of the second winding 40 is a Litz wire in which a plurality of enameled wires are twisted together. The second winding 40 is a secondary winding on the output side connected to a load device (not shown). In a state where the overlapping winding 31 of the first winding 30 and the overlapping portion 10a1 of the first cylindrical portion 10a around which it is wound are inserted through the second cylindrical portion 20a, the second winding 40 overlaps the overlapping winding 31 of the first winding 30 in the radial direction. Note that the second winding 40 may be wound around the second cylindrical portion 20a in a plurality of layers.

[0018] The cover component 3 has an end wall portion 26 and a cover portion 27. The end wall portion 26 is provided on the side opposite to the first bobbin 10 with the second bobbin 20 interposed therebetween in the axial direction. The end wall portion 26 is formed in a plate shape with the axial direction as the thickness direction. The outer shape of the end wall portion 26 is the same as the outer shape of the first flange portion 10c when viewed from the axial direction. An insertion hole 26a penetrating the end wall portion 26 in the axial direction is formed in the end wall portion 26. The insertion hole 26a is formed in the same shape as the inner peripheral surface of the first cylindrical portion 10a when viewed from the axial direction. The insertion hole 26a communicates with the first cylindrical portion 10a.

[0019] The cover portion 27 opens radially outward at a part of the circumferential direction of the outer edge of the end wall portion 26. The opening of the cover portion 27 functions as an injection port 3a (see FIG. 1) of the cover component 3 into which a filling resin (not shown) for protecting the first winding 30 and the second winding 40 of the coil component 1 is injected. The injection port 3a also functions as an outlet for the end 30a of the wire of the first winding 30 and the end 40a of the wire of the second winding 40. The cover portion 27 has a first cover structure 27a and a second cover structure 27b arranged in the axial direction. The first cover structure 27a extends axially from the outer edge of the end wall portion 26 to the outer edge of the second flange portion 20b of the second bobbin 20. Thereby, the first cover structure 27a overlaps the overlapping portion 10a1 of the first cylindrical portion 10a and the outside of the second cylindrical portion 20a in the radial direction. The first cover structure 27a covers the overlapping winding 31 of the first winding 30 and the second winding 40 from the outside in the radial direction. The second cover structure 27b is formed adjacent to the second cylindrical portion 20a in the axial direction. The second cover structure 27b extends axially from the outer edge of the second flange portion 20b to the outer edge of the first flange portion 10c of the first bobbin 10. Thereby, the second cover structure 27b overlaps the outside of the non-overlapping portion 10a2 of the first cylindrical portion 10a in the radial direction and is arranged axially with respect to the first cover structure 27a. The second cover structure 27b covers the non-overlapping winding 32 of the first winding 30 from the outside in the radial direction.

[0020] The core 2 is a member made of a magnetic material such as ferrite. As shown in FIG. 2, the core 2 is formed by two core pieces 50. Since the two core pieces 50 are substantially the same, only one of the core pieces 50 will be described. The core piece 50 has an inner piece 51 formed in a cylindrical shape, two outer pieces 52 disposed on both sides in the radial direction with respect to the inner piece 51, and a connecting piece 53 that connects the two outer pieces 52 in the radial direction.

[0021] The axial length of the inner piece 51 is longer in the core piece 50 on the first bobbin 10 side among the two core pieces 50. Hereinafter, the core piece 50 on the first bobbin 10 side among the two core pieces 50 is referred to as the first cylindrical portion 2a, and the core piece 50 on the second bobbin 20 side is referred to as the second cylindrical portion 2b. Each of the two outer pieces 52 is formed in a rectangular plate shape in which the thickness direction coincides with the direction orthogonal to the opening direction of the injection port 3a in the radial direction. The two outer pieces 52 are spaced apart on both sides of the inner piece 51 in the radial direction. The axial length of the outer piece 52 is longer in the core piece 50 on the first bobbin 10 side among the two core pieces 50. The connecting piece 53 is formed in a rectangular plate shape in which the thickness direction coincides with the axial direction. The axial end of the inner piece 51 is continuous with the connecting piece 53. A concave portion 53a is formed on the end surface of the connecting piece 53 on the side where the injection port 3a opens. The concave portion 53a is formed in a tapered shape that widens as it goes from the bottom 53a2 thereof toward the end surface of the connecting piece 53 where the concave portion 53a opens. The concave portion 53a has a flat bottom 53a2 and two flat side portions 53a1 that slope and extend from both sides of the bottom 53a2 to the end surface of the connecting piece 53.

[0022] The above-mentioned core piece 50 is formed in an E shape when viewed from the opening direction of the injection port 3a. The two core pieces 50 are attached to the first bobbin 10, the second bobbin 20, and the cover part 3 by inserting their respective inner pieces 51 into the inside of the first cylindrical part 10a from opposite sides in the axial direction. In a state where the two core pieces 50 are attached to the first bobbin 10, the second bobbin 20, and the cover part 3, the tips of the outer pieces 52 of the two core pieces 50 abut against each other. The outer pieces 52 of the two abutting core pieces 50 are fixed, for example, by adhesion or the like. In a state where the two core pieces 50 are attached to the first bobbin 10, the second bobbin 20, and the cover part 3, the connecting piece 53 of the two core pieces 50 is arranged so as to sandwich the first bobbin 10, the second bobbin 20, and the cover part 3 in the axial direction. The inner pieces 51 of the two core pieces 50 inserted into the inside of the first cylindrical part 10a are spaced apart in the axial direction inside the first cylindrical part 10a. That is, the first cylindrical part 2a and the second cylindrical part 2b inserted into the inside of the first cylindrical part 10a are arranged with a gap 2c in the axial direction. That is, the core 2 has a gap 2c in the middle part in the axial direction located inside the first cylindrical part 10a. The gap 2c overlaps the wall part 10b in the radial direction. The width D2 of the gap 2c in the axial direction is shorter than the width of the wall part 10b in the axial direction. Both ends of the gap 2c in the axial direction are located inside the wall part 10b in the axial direction. The gap 2c does not overlap the second winding 40 in the radial direction.

[0023] The terminal blocks 8 are provided one by one on the end wall part 26 of the cover part 3 and the first flange part 10c of the first bobbin 10. The terminal blocks 8 are provided at the ends in the opening direction of the injection port 3a in the end wall part 26 and the first flange part 10c. The terminal block 8 includes a terminal block main body 8a and a pedestal 8b. Only the terminal block 8 on the side of the end wall part 26 among the two terminal blocks 8 will be described. Since the terminal block 8 on the side of the first flange part 10c has the same configuration as the terminal block 8 on the side of the end wall part 26, the description thereof will be omitted. The terminal block 8 is integrally formed with the end wall portion 26. The terminal block main body 8a projects axially outward from the end wall portion 26. The terminal block main body 8a extends in a direction orthogonal to the axial direction and the opening direction of the injection port 3a. The end face of the terminal block main body 8a on the side opposite to the opening direction of the injection port 3a is along the recess 53a. Thereby, the terminal block main body 8a is fitted into the recess 53a. The pedestal 8b is a rectangular plate-like member provided at both longitudinal ends of the terminal block main body 8a. The thickness direction of the pedestal 8b coincides with the opening direction of the injection port 3a. The pedestal 8b is placed on the end face of the connecting piece 53 on the side where the recess 53a opens. A nut placement portion 8c for arranging a hexagonal nut is formed in the pedestal 8b. The nut placement portion 8c is a recess formed in a hexagonal shape when viewed from the side opposite to the opening direction of the injection port 3a. Each pedestal 8b has a terminal 9 attached thereto.

[0024] The terminal 9 is formed of a metal material such as copper, for example. The terminal 9 has a terminal main body 9a and a support portion 9b. The terminal main body 9a is formed in a rectangular plate shape whose thickness direction coincides with the opening direction of the injection port 3a. The terminal main body 9a is placed on the pedestal 8b. The terminal main body 9a has a claw portion extending toward the pedestal 8b side, and is fixed to the pedestal 8b by snap fit by the claw portion. A through hole 9c penetrating the terminal main body 9a in the thickness direction is provided in the terminal main body 9a. A hexagonal nut is arranged between the terminal main body 9a and the pedestal 8b. The hexagonal nut is non-rotatably arranged in the nut placement portion 8c of the pedestal 8b. A terminal (not shown) of an external power circuit is connected to the terminal main body 9a by, for example, bolt fastening. The support part 9b is provided inside a pair of terminal bodies 9a. The support part 9b extends along the axial direction. The end part on the outer side in the axial direction of the support part 9b is located on the outer side in the axial direction than the terminal body 9a. The end part on the outer side in the axial direction of the support part 9b is formed in a U shape that opens to the inner side in the facing direction in the pair of terminal bodies 9a when viewed from the axial direction. Inside the end part on the outer side in the axial direction of the support part 9b, the end parts 30a, 40a of the wire materials constituting the winding 30, 40 are arranged. The end parts 30a, 40a are fixed to the support part 9b by being welded or the like in a state of being clamped to the end part on the outer side in the axial direction of the support part 9b.

[0025] In the transformer to which the coil component 1 is applied, the electrical coupling between the first winding 30 and the second winding 40 is dense in the overlapping winding 31 and sparse in the non-overlapping winding 32. Therefore, the leakage inductance generated between the first winding 30 and the second winding 40 becomes small in the overlapping winding 31 and large in the non-overlapping winding 32. For this reason, by adjusting the number of turns of the non-overlapping winding 32 of the first winding 30, the leakage inductance can be changed without changing the relative positional relationship between the first winding 30 and the second winding 40 and the number of turns of the overlapping winding 31 of the first winding 30 and the second winding 40. Thereby, the leakage inductance can be adjusted to an appropriate size while suppressing a change in the volume of the transformer.

[0026] As described above, according to the coil component 1 according to the first embodiment, the first bobbin 10 has a wall part 10b protruding from the outer peripheral surface of the first cylindrical part 10a at a position overlapping the gap 2c in the radial direction of the first cylindrical part 10a. The first winding 30 is wound around both axial sides of the wall part 10b in the first cylindrical part 10a. Thereby, it is possible to suppress at least a part of the first winding 30 from overlapping the gap 2c in the radial direction. For this reason, compared with the case where the first winding 30 is wound around the outer side in the radial direction of the gap 2c, the region of the first winding 30 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Therefore, since the eddy current loss generated when the leakage magnetic flux passes through the wire material of the first winding 30 can be suppressed, the heat generation of the wire material of the first winding 30 can be suppressed.

[0027] In the first embodiment, the wall portion 10b protrudes from the entire circumferential direction of the outer peripheral surface of the first cylindrical portion 10a. As a result, by winding the winding around both outer sides in the axial direction with respect to the wall portion 10b, it is possible to surely suppress the first winding 30 from overlapping with the gap 2c in the radial direction over the entire circumferential direction. For this reason, compared with the case where the wall portion 10b protrudes from a part of the circumferential direction of the outer peripheral surface, the region of the first winding 30 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Therefore, since the eddy current loss generated by the leakage magnetic flux passing through the wire material of the first winding 30 can be suppressed, the heat generation of the wire material of the first winding 30 can be suppressed.

[0028] In the first embodiment, guide passages 10b1 and 10b2 through which the winding passes axially are formed in the wall portion 10b. Thereby, the wire material constituting the first winding 30 can be passed through the guide passages 10b1 and 10b2. For this reason, the first winding 30 can be wound around both outer sides in the axial direction with respect to the wall portion 10b without winding the wire material around the outer side in the radial direction of the wall portion 10b in the circumferential direction. Therefore, compared with the case where the wire material of the first winding 30 is wound around the outer side in the radial direction of the wall portion 10b in the circumferential direction, the region of the first winding 30 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Therefore, since the eddy current loss generated by the leakage magnetic flux passing through the wire material of the first winding 30 can be suppressed, the heat generation of the wire material of the first winding 30 can be suppressed.

[0029] In the first embodiment, the first guide passage 10b1 is inclined in the circumferential direction with respect to the axial direction of the first cylindrical portion 10a. For this reason, in the first winding 30, the angular difference between the direction in which the wire material is wound around the first cylindrical portion 10a (substantially the circumferential direction) and the direction in which the wire material passes through the first guide passage 10b1 can be reduced. Thereby, the angle by which the wire material is bent to pass through the first guide passage 10b1 can be reduced. Therefore, the stress applied to the portion of the wire material passing through the first guide passage 10b1 can be reduced.

[0030] In the first embodiment, the width of the wall portion 10b in the axial direction is wider than the width D2 of the gap. As a result, the first winding 30 can be wound radially outside the gap 2c, so that the first winding 30 can be prevented from overlapping the gap 2c in the radial direction. Therefore, compared with the case where the first winding 30 is wound outside the gap 2c in the radial direction, the region of the first winding 30 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Therefore, the eddy current loss generated when the leakage magnetic flux passes through the wire of the first winding 30 can be suppressed, so that the heat generation of the wire of the first winding 30 can be suppressed.

[0031] In the first embodiment, the first bobbin 10 has an annular first flange portion 10c protruding from the outer peripheral surface of the first cylindrical portion 10a at one axial end of the first cylindrical portion 10a. Therefore, the first winding 30 wound around the first cylindrical portion 10a is supported from the outside in the axial direction of the first cylindrical portion 10a by the first flange portion 10c. Therefore, it is possible to suppress or prevent the wire of the first winding 30 from unwinding outside the first cylindrical portion 10a in the axial direction.

[0032] In the first embodiment, the first bobbin 10 includes a first bobbin component 11 and a second bobbin component 12 that are arranged in the axial direction and connected to each other. As a result, by preparing a plurality of types of the first bobbin component 11 and the second bobbin component 12 having different axial lengths, respectively, these plurality of types of the first bobbin component 11 and the second bobbin component 12 can be appropriately combined to easily manufacture more types of the first bobbin 10. Furthermore, since the wall portion 10b is provided on the first bobbin component 11, the position of the wall portion 10b can be easily adjusted by appropriately combining the second bobbin component 12. Therefore, even when the position of the gap 2c changes due to a change in the specifications of the core 2, the region of the first winding 30 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Thus, the eddy current loss generated when the leakage magnetic flux passes through the wire of the first winding 30 can be suppressed, so that the heat generation of the wire of the first winding 30 can be suppressed.

[0033] In the first embodiment, the first flange portion 10c may be provided not only at one axial end of the first cylindrical portion 10a but also at the other axial end of the first cylindrical portion 10a. The first flange portion 10c provided at the other end of the first cylindrical portion 10a may be integrally formed with the first cylindrical portion 10a, or may be formed separately from the first cylindrical portion 10a and then connected to the first cylindrical portion 10a. Further, the first bobbin 10 may not have the first flange portion 10c.

[0034] In the first embodiment, both ends of the gap 2c of the core 2 in the axial direction may overlap both ends of the wall portion 10b in the axial direction.

[0035] 〔Second Embodiment〕 Next, a second embodiment of the present invention will be described with reference to FIG. 6. In the second embodiment, the same reference numerals are given to the same components as in the first embodiment, and the description thereof will be omitted. In FIG. 6, the second bobbin 20 and the second winding 40 are omitted.

[0036] As shown in FIG. 6, the coil component 1A of the present embodiment has the same configuration as the coil component 1 of the first embodiment, but is different from the coil component 1 of the first embodiment in the following points. The width D2 of the gap 2c of the core 2 in the axial direction is longer than the width of the wall portion 10b of the first bobbin 10 in the axial direction. Both ends of the gap 2c in the axial direction are located outside the wall portion 10b in the axial direction. The length D3 from the end of the wall portion 10b on the first cylindrical portion 2a side to the end of the gap 2c on the first cylindrical portion 2a side in the axial direction, and the length D4 from the end of the wall portion 10b on the second cylindrical portion 2b side to the end of the gap 2c on the second cylindrical portion 2b side in the axial direction are each equal to or less than the wire diameter D1 of the wire constituting the first winding 30.

[0037] According to the second embodiment, basically the same effects as those of the first embodiment are achieved, but it is different from the first embodiment in the following points. In the second embodiment, since both ends of the gap 2c of the core 2 in the axial direction are located outside the wall portion 10b in the axial direction, a part of the wire of the first winding 30 wound around the first cylindrical portion 10a and extending in the circumferential direction is located near the wall portion 10b in the axial direction, so that a part of the wire can overlap the gap 2c in the radial direction. However, the lengths D3 and D4 from the end of the wall portion 10b to the end of the gap 2c in the axial direction are equal to or less than the wire diameter D1 of the wire of the first winding 30. Thereby, it is possible to prevent the entire wire of the first winding 30 adjacent to the wall portion 10b in the axial direction from overlapping the gap 2c in the radial direction. For this reason, compared with the case where the lengths D3 and D4 from the end of the wall portion 10b to the end of the gap 2c in the axial direction are larger than the wire diameter of the wire of the first winding 30, the region of the first winding 30 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Therefore, since the eddy current loss generated by the leakage magnetic flux passing through the wire of the first winding 30 can be suppressed, the heat generation of the wire of the first winding 30 can be suppressed.

[0038] In the second embodiment, one of the two ends of the gap 2c of the core 2 in the axial direction may be located inside the wall portion 10b in the axial direction or may overlap the end of the wall portion 10b in the axial direction.

[0039] 〔Third Embodiment〕 Next, a second embodiment of the present invention will be described with reference to FIG. 7. In the second embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted. In FIG. 7, the second bobbin 20 and the second winding 40 are omitted.

[0040] As shown in FIG. 7, the coil component 1B of the present embodiment has the same configuration as the coil component 1 of the first embodiment, but is different from the coil component 1 of the first embodiment in the following points. In the first bobbin 10, the protruding height of the wall portion 10b protruding from the outer peripheral surface of the first cylindrical portion 10a is smaller than the thickness of the first winding 30 in the radial direction, and is substantially the same as the wire diameter of the wire constituting the first winding 30. Only one guide passage 10b3 penetrating the wall portion 10b in the axial direction is formed in the wall portion 10b. The guide passage 10b3 is the same as either one of the first guide passage 10b1 and the second guide passage 10b2 (see FIG. 5) of the first embodiment, for example. The first flange portion 10c is formed at both axial ends of the first cylindrical portion 10a. The overlapping portion 10a1 and the non-overlapping portion 10a2 of the first cylindrical portion 10a are integrally formed.

[0041] The first winding 30 has a base layer 33 formed by winding a wire around the outer peripheral surface of the first cylindrical portion 10a in one layer, and a second layer 34 formed by winding a wire around the outer side in the radial direction of the base layer 33 in one layer. The wire constituting the base layer 33 is wound so as to mainly extend in the circumferential direction of the first cylindrical portion 10a on the outer peripheral surfaces of the overlapping portion 10a1 and the non-overlapping portion 10a2 located on both sides of the wall portion 10b in the axial direction. The wire constituting the base layer 33 mainly extends in the axial direction of the first cylindrical portion 10a in the guide passage 10b3 of the wall portion 10b. The thickness of the base layer 33 in the radial direction is substantially the same as the protruding height of the wall portion 10b in the radial direction. The wire constituting the second layer 34 is wound so as to mainly extend in the circumferential direction of the first cylindrical portion 10a so as to overlap the outer side in the radial direction of the base layer 33 and the wall portion 10b.

[0042] According to the third embodiment, it basically has the same effects as the first embodiment, but is different from the first embodiment in the following points. Among the wire materials constituting the base layer 33 of the first winding 30, the portion overlapping with the gap 2c of the core 2 in the radial direction extends mainly in the axial direction of the first cylindrical portion 10a by passing through the guide passage 10b3 of the wall portion 10b. Thereby, the length of the wire material of the base layer 33 overlapping with the gap 2c of the core 2 can be suppressed to be short, and the region of the base layer 33 through which the leakage magnetic flux generated in the gap 2c passes can be narrowed. Therefore, since the eddy current loss generated by the leakage magnetic flux passing through the wire material of the base layer 33 can be suppressed, the heat generation of the wire material forming the base layer 33 can be suppressed.

[0043] On the other hand, among the wire materials constituting the second layer 34 of the first winding 30, the portion (overlapping portion) overlapping with the gap 2c of the core 2 in the radial direction extends in the circumferential direction of the first cylindrical portion 10a, so the length of the wire material overlapping with the gap 2c becomes long, but in the radial direction, it is located farther from the gap 2c of the core 2 than the base layer 33. For this reason, the eddy current loss generated in the overlapping portion of the wire material constituting the second layer 34 due to the leakage magnetic flux generated in the gap 2c of the core 2 can be suppressed to be small, and the heat generation of the wire material constituting the second layer 34 can be suppressed. Therefore, similarly to the first embodiment, the heat generation of the wire material constituting the first winding 30 can be suppressed.

[0044] In the third embodiment, the base layer 33 of the first winding 30 may be wound around the outer peripheral surface of the first cylindrical portion 10a in a plurality of layers. Further, the second layer 34 of the first winding 30 may be wound around the outer side in the radial direction of the base layer 33 and the wall portion 10b in a plurality of layers.

[0045] As described above, the embodiments according to the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, the first winding 30 may be a secondary winding, and the second winding 40 may be a primary winding. Further, the wire diameter of the wire material of the second winding 40 may be equal to the wire diameter D1 of the wire material of the first winding 30, or may be larger or smaller than the wire diameter D1 of the wire material of the first winding 30.

[0046] In the present invention, the coil component 1 may not include the second bobbin 20. For example, an insulating tape may be wound around the outer peripheral surface of the first winding 30, and the second winding 40 may be wound on top of the insulating tape.

[0047] In the present invention, the wall portion 10b may not protrude radially outward from the entire circumferential direction of the outer peripheral surface of the first cylindrical portion 10a. The wall portion 10b may protrude radially outward from at least a part in the circumferential direction of the outer peripheral surface of the first cylindrical portion 10a.

[0048] The coil component 1 of the present invention may be applied not only to a transformer but also to a choke coil or the like. The coil component may include at least the first bobbin 10, the first winding 30, and the core 2.

Explanation of Reference Numerals

[0049] 1, 1A, 1B Coil component 2 Core 2c Gap 10 First bobbin (bobbin) 10a First cylindrical portion (cylindrical portion) 10b Wall portion 10b1, 10b2, 10b3 Guide passage 11 First bobbin structure (bobbin structure) 12 Second bobbin structure (bobbin structure) 30 First winding (winding) D1 Wire diameter D2 Width D3, D4 Length from the end of the wall portion 10b to the end of the gap 2c

Claims

Claim 1 A bobbin having a cylindrical portion, A winding wound around the cylindrical portion, A core inserted through the cylindrical portion and having a gap at a position within the cylindrical portion, Comprising: The bobbin has a wall portion protruding from the outer peripheral surface of the cylindrical portion at a position overlapping the gap in the radial direction of the cylindrical portion, The winding is wound around both axial sides of the wall portion in the cylindrical portion, The bobbin includes two bobbin components connected to each other in the axial direction, and a coil component in which the wall portion is provided only on one of the bobbin components. Claim 2 The coil component according to claim 1, wherein the wall portion protrudes from the entire circumferential direction of the outer peripheral surface. Claim 3 The coil component according to claim 1 or 2, wherein a guide passage through which the winding passes axially through the wall portion is formed. Claim 4 The coil component according to any one of claims 1 to 3, wherein the width of the wall portion in the axial direction is wider than the width of the gap. Claim 5 The width of the wall portion in the axial direction is narrower than the width of the gap, The coil component according to any one of claims 1 to 3, wherein the length from the end of the wall portion to the end of the gap in the axial direction is equal to or less than the wire diameter of the winding.

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