Coil body

Abstract

To improve rigidity of a coil body.SOLUTION: A coil body is a coil body formed by spirally winding a metal strand, and comprises: M layers (M≥1 is satisfied) of first spiral parts which are formed of P (P≥1 is satisfied) first metal strands; and N (N>M) layers of second spiral parts whose dimension in at least a radial direction of the coil body is smaller than that of the first metal strands, and are formed of Q (Q≥2) second metal strands. The first spiral parts are configured so that, there are formed spiral gaps where the adjacent first metal strands are separated in an axial direction of the coil body, and the second spiral parts are provided in the respectively gaps.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The technology disclosed in this specification relates to a coil body.

Background Art

[0002] Conventionally, for example, a coil body is used as a part of devices used for various applications such as medical applications. For example, a connection wire provided in a treatment tool for an endoscope is configured by spirally winding a stranded wire composed of a plurality of strands having the same outer diameter (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The coil body is required to have flexibility according to the application. In the conventional coil body, only a single outer diameter strand (stranded wire) is wound. For this reason, there are problems such that in a coil body composed of relatively thin strands, the flexibility is too high, and in a coil body composed of relatively thick strands, the rigidity is too high.

[0005] This specification discloses a technology capable of solving the above-described problems.

Means for Solving the Problems

[0006] The technology disclosed in this specification can be realized, for example, in the following forms.

[0007] (1) The coil body disclosed in this specification is a coil body formed by spirally winding a metal wire. It includes M (where M≥1) layers of a first spiral portion formed by P (where P≥1) of the first metal wires, and N (where N>M) layers of a second spiral portion formed by Q (where Q≥2) of the second metal wires, the radial dimension of which is smaller than that of the first metal wire at least in the radial direction of the coil body. In the first spiral portion, a spiral gap is formed between adjacent first metal wires, which are spaced apart in the axial direction of the coil body, and the second spiral portion is arranged to be interposed in the gap.

[0008] The coil shape of this coil body is formed by a first spiral portion and a second spiral portion that is more flexible than the first spiral portion. Therefore, for example, compared with a configuration in which the coil shape is formed only by the first metal wires of the M layers, the flexibility of the coil body can be improved. Also, for example, compared with a configuration in which the coil shape is formed only by the second metal wires of the N layers, the rigidity of the coil body can be improved.

[0009] (2) In the above coil body, the cross-sectional shape perpendicular to the axial direction of the second metal wire may be rectangular, and the flat surfaces of the second metal wires adjacent to each other in the radial direction of the coil body may face each other. In this coil body, since the flat surfaces of the second metal wires adjacent to each other in the radial direction of the coil body face each other, the positional relationship between the two is stable. Therefore, according to this coil body, for example, compared with a configuration in which the cross-sectional shape of the second metal wire is circular, problems such as the second metal wire on the outer layer side getting into the space between the second metal wires on the inner layer side can be suppressed.

[0010] (3) In the coil body, the cross-sectional shape perpendicular to the axial direction of the first metal wire may be rectangular, and among the first metal wires, the opposing surface with the second metal wire adjacent in the axial direction of the coil body may be a flat surface. According to this coil body, for example, compared with a configuration in which the cross-sectional shape of the first metal wire is circular, it is possible to suppress the displacement of the position of the second metal wire with respect to the first metal wire.

[0011] Note that the technology disclosed in this specification can be realized in various forms. For example, it can be realized in the form of a coil body, a method for manufacturing a coil body, etc.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0013] A. First Embodiment: A-1. Configuration of the Coil Body 100: FIG. 1 is a perspective view showing the external configuration of the coil body 100 in the first embodiment. In FIG. 1, illustration of a part of the coil body 100 is omitted. FIG. 2 is an explanatory view showing the cross-sectional configuration of the coil body 100. The cross-section of the coil body 100 refers to a cross-section (XY cross-section in FIG. 1) perpendicular to the direction along the central axis L of the coil body 100 (longitudinal direction, Z-axis direction in FIG. 1, hereinafter referred to as the "axial direction of the coil body 100"). FIG. 3 is an explanatory view showing the longitudinal-sectional configuration of the coil body 100. The longitudinal section of the coil body 100 refers to a cross-section (YZ cross-section in FIG. 1) parallel to the axial direction of the coil body 100. In FIG. 1, a state is shown in which the coil body 100 is in a straight line shape parallel to the Z-axis direction as a whole, but the coil body 100 has flexibility to the extent that it can be curved.

[0014] The coil body 100 is used, for example, as a component of a long medical device inserted into a blood vessel or the like. Specifically, the coil body 100 is a coil body that constitutes a guide wire or a guiding catheter for guiding a catheter to a lesion (stenosis or occlusion) in a blood vessel or the like, or is used as a connection wire inserted into a sheath in an endoscopic treatment tool and having a circumferential cutting device connected to its tip.

[0015] As shown in FIG. 1, the coil body 100 is a coil-shaped member formed in a hollow cylindrical shape by spirally winding metal wires (the first metal wire 14 and the second metal wire 24 described later). As the metal material for forming the metal wire, for example, radiation-transparent materials such as stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni-Ti alloy, piano wire, or radiation-opaque materials such as platinum, gold, tungsten, or alloys thereof are used.

[0016] The coil body 100 includes a first spiral portion 10 and a second spiral portion 20.

[0017] The first spiral portion 10 is a portion of M (where M ≥ 1) layers formed by P (where P ≥ 1) first metal wires 14. The first metal wire 14 is a round wire having a circular cross-sectional shape perpendicular to the axial direction of the first metal wire 14. In FIGS. 2 and 3, for convenience, the shape of the first metal wire 14 in the longitudinal and transverse cross-sections of the coil body 100 is depicted as circular, but in reality, it becomes elliptical according to the inclination angle of the first metal wire 14 with respect to the axial direction of the coil body 100.

[0018] In this embodiment, the first spiral portion 10 has a pair of first divided portions 12. Each first divided portion 12 is a single-layer coil formed by spirally winding one first metal wire 14. The pair of first divided portions 12 are arranged such that one first metal wire 14 forming one first divided portion 12 and one first metal wire 14 forming the other first divided portion 12 are alternately arranged while being spaced apart in the axial direction of the coil body 100. With such an arrangement, a spiral first gap S1 in which adjacent first metal wires 14 are spaced apart in the axial direction of the coil body 100 is formed in the first spiral portion 10 (see FIGS. 1 and 3). In this embodiment, the number P of the first metal wires 14 forming the first spiral portion 10 is 2, and the number M of layers of the first spiral portion 10 is 1 layer.

[0019] The second spiral portion 20 is a portion of N (where N > M) layers formed by Q (where Q ≥ 2) second metal wires 24. The second metal wire 24 has at least a smaller dimension in the radial direction of the coil body 100 (hereinafter referred to as "thickness") than the first metal wire 14. The second metal wire 24 is a round wire having a circular cross-sectional shape perpendicular to the axial direction of the second metal wire 24. In FIGS. 2 and 3, for convenience, the shape of the second metal wire 24 in the longitudinal and transverse cross-sections of the coil body 100 is depicted as circular, but in reality, it becomes elliptical according to the inclination angle of the second metal wire 24 with respect to the axial direction of the coil body 100.

[0020] In this embodiment, the second spiral portion 20 has a pair of second divided portions 22. Each second divided portion 22 is a two-layer coil formed by spirally winding eight second metal wires 24. Specifically, each second divided portion 22 has an inner layer portion 30 and an outer layer portion 40 disposed on the outer peripheral side of the inner layer portion 30 (see FIGS. 2 and 3). Both the inner layer portion 30 and the outer layer portion 40 are multi-strand coils formed by winding four second metal wires 24 adjacent to each other in the axial direction of the coil body 100. In FIGS. 1 and the like, the four second metal wires 24 are wound tightly, but they may be wound loosely. Note that the second spiral portion 20 is not configured such that a plurality of second metal wires 24 are twisted together, but is configured such that parallel lines in which a plurality of second metal wires 24 are arranged in parallel are spirally wound.

[0021] The thickness D3 of the second metal wire 24 (hereinafter referred to as "inner second metal wire 24A") constituting the inner layer portion 30 is the same as the thickness D4 of the second metal wire 24 (hereinafter referred to as "outer second metal wire 24B") constituting the outer layer portion 40. Here, in this specification, "the dimensions of member A and the dimensions of member B are the same" means that they are substantially the same. For example, it means that the ratio of the dimensional difference between the two to the dimension of the member with the smaller dimension among member A and member B is 5% or less.

[0022] On the other hand, the dimension (hereinafter referred to as "width") W2 of the outer second metal wire 24B in the direction perpendicular to the radial direction of the coil body 100 is wider than the width W3 of the inner second metal wire 24A and is close to the width W1 of the first metal wire 14. Also, the inner layer portion 30 and the outer layer portion 40 are in contact with each other in the radial direction of the coil body 100. Specifically, the outer peripheral surface of each second metal wire 24A and the inner peripheral surface of each second metal wire 24B are in contact with each other. The outer second metal wire 24B is an example of the second metal wire located in the outermost layer in the claims.

[0023] The pair of second divided portions 22 are arranged such that eight second metal wires 24 (four inner second metal wires 24A and four outer second metal wires 24B) forming one second divided portion 22 and eight second metal wires 24 forming the other second divided portion 22 are alternately arranged while being spaced apart in the axial direction of the coil body 100. With such an arrangement, a spiral second gap S2 in which adjacent second metal wires 24 are spaced apart in the axial direction of the coil body 100 is formed in the second spiral portion 20 (see FIGS. 1 and 3). In the present embodiment, the number Q of the second metal wires 24 forming the second spiral portion 20 is 16, and the number of layers N of the second spiral portion 20 is two layers.

[0024] As shown in FIGS. 1 and 3, the second spiral portion 20 (second divided portion 22) is arranged so as to intervene in the first gap S1 of the first spiral portion 10. This can also be said to be an arrangement in which the first spiral portion 10 (first divided portion 12) intervenes in the second gap S2 of the second spiral portion 20. In short, the first divided portion 12 constituting the first spiral portion 10 and the second divided portion 22 constituting the second spiral portion 20 are arranged so as to be alternately arranged in the axial direction of the coil body 100.

[0025] As shown in FIG. 2, in the cross section of the coil body 100, the pair of first divided portions 12 are arranged at positions symmetric to each other with respect to the central axis L of the coil body 100. Also, in the cross section of the coil body 100, the pair of second divided portions 22 are arranged at positions symmetric to each other with respect to the central axis L of the coil body 100.

[0026] As shown in FIGS. 2 and 3, the thickness D1 of the first spiral portion 10 is the same as the thickness (D2 = D3 + D4) of the second spiral portion 20. Also, the first spiral portion 10 and the second spiral portion 20 are in contact with each other in the circumferential direction of the coil body 100. Specifically, each of a pair of second metal wires 24A located at both ends of the inner layer portion 30 is in contact with the first metal wire 14, and each of a pair of second metal wires 24B located at both ends of the outer layer portion 40 is in contact with the first metal wire 14. Thus, in the coil body 100, the first metal wire 14 and the second metal wire 24 are wound in a closely wound state.

[0027] A-2. Manufacturing method of the coil body 100: Next, an example of the manufacturing method of the coil body 100 of the present embodiment will be described. First, the first metal wire 14 and the second metal wire 24 are prepared. Next, the first metal wire 14 forming the first spiral portion 10 and the second metal wire 24A forming the inner layer portion 30 of the second spiral portion 20 are wound around a mandrel (not shown) to form a coil shape. Specifically, one first metal wire 14, four second metal wires 24A, one first metal wire 14, and four second metal wires 24A are wound so as to be arranged in the axial direction of the mandrel. Next, four second metal wires 24B forming the outer layer portion 40 are wound around the outer circumferences of the respective four second metal wires 24A. Next, heat treatment is performed on the first metal wire 14 and the second metal wire 24 wound around the mandrel, and then the mandrel is extracted. By the above manufacturing method, the coil body 100 having the above-described configuration is manufactured.

[0028] A-3. Effects of the first embodiment: As described above, the coil body 100 of the first embodiment includes a first spiral portion 10 and a second spiral portion 20. By arranging the second spiral portion 20 to be interposed in the spiral first gap S1 in the first spiral portion 10, the coil shape of the coil body 100 is formed (see FIGS. 1 and 3). The second metal wire 24 forming the second spiral portion 20 has a smaller dimension in the radial direction of the coil body 100 than the first metal wire 14 forming the first spiral portion 10 (see FIG. 2). For this reason, the second spiral portion 20 is more flexible than the first spiral portion 10. For this reason, for example, compared with a configuration in which the coil shape is formed only by the first spiral portion 10, the flexibility of the coil body 100 can be improved, and for example, compared with a configuration in which the coil shape is formed only by the second spiral portion 20, the rigidity of the coil body 100 can be improved.

[0029] Further, the second spiral portion 20 is formed by a group of N layers of wires, which is more than the M layers of the first spiral portion 10, by the relatively thin second metal wire 24. Thereby, the gap between the thickness of the first spiral portion 10 and the thickness of the second spiral portion 20 is suppressed. Therefore, according to the present embodiment, for example, compared with a configuration in which the number of layers of the second spiral portion 20 is the same as the number of layers (M layers) of the first spiral portion 10, the dimensional gap in the radial direction between the first spiral portion 10 and the second spiral portion 20 can be suppressed.

[0030] In such a configuration, for example, if the ratio of the second spiral portion 20 to the first spiral portion 10 (such as the ratio of the number of wires or the ratio of the thickness of the wires) is increased, the flexibility of the coil body 100 is increased, and if the same ratio is decreased, the flexibility of the coil body 100 can be decreased. Thus, by adjusting the same ratio, a coil body 100 having appropriate flexibility according to each application can be provided.

[0031] In this embodiment, the width W2 of the outer second metal wire 24B is wider than the width W3 of the inner second metal wire 24A and is close to the width W1 of the first metal wire 14. According to this embodiment, for example, compared with a configuration in which the width W2 of the outer second metal wire 24B is the same as the thickness D4 of the outer second metal wire 24B, the width gap between the first metal wire 14 and the second metal wire 24 on the outer peripheral side of the coil body 100 is suppressed. As a result, for example, it is possible to suppress the concentration of stress at a specific location due to distortion or the like of each spiral portion 10, 20 caused by the gap.

[0032] In the cross section of the coil body 100, the pair of first divided portions 12 are arranged at positions symmetric to each other with respect to the central axis L of the coil body 100 (see FIG. 2). Also, in the cross section of the coil body 100, the pair of second divided portions 22 are arranged at positions symmetric to each other with respect to the central axis L of the coil body 100. According to this embodiment, compared with a configuration in which at least one of the first metal wire 14 and the second metal wire 24 is arranged asymmetrically with respect to the central axis L of the coil body 100, it is possible to suppress the bias in flexibility in the circumferential direction of the coil body 100.

[0033] B. Second Embodiment: FIG. 4 is an explanatory diagram showing a cross-sectional configuration of a coil body 100a in the second embodiment, and FIG. 5 is an explanatory diagram showing a longitudinal cross-sectional configuration of the coil body 100a and a coil body 100b of a comparative example. FIG. 5(A) shows a longitudinal cross-sectional configuration of a part of the coil body 100a, and FIG. 5(B) shows a longitudinal cross-sectional configuration of a part of a coil body 100b of a comparative example described later. Hereinafter, among the configurations of the coil body 100b of the second embodiment, the same configurations as those of the coil body 100 of the first embodiment described above will be denoted by the same reference numerals, and the description thereof will be appropriately omitted.

[0034] In the above-described first embodiment, the metal wire elements (the first metal wire element 14 and the second metal wire element 24) constituting the coil body 100 were round wires. In contrast, in the present second embodiment, the metal wire elements (the first metal wire element 14a and the second metal wire element 24a) constituting the coil body 100a are flat wires having a flat cross-sectional shape perpendicular to the axial direction of the wire element.

[0035] The coil body 100a includes a first helical portion 10a and a second helical portion 20a.

[0036] As shown in FIGS. 4 and 5(A), the first helical portion 10a has a pair of first divided portions 12a. Each first divided portion 12a has the same configuration as the first divided portion 12 of the first embodiment, except that the first metal wire element 14a forming the first divided portion 12a is a flat wire. The second helical portion 20a has a pair of second divided portions 22a. Each second divided portion 22a has the same configuration as the second divided portion 22 of the first embodiment, except that the second metal wire elements 24a (the inner second metal wire element 24Aa and the outer second metal wire element 24Ba) forming the second divided portion 22a are flat wires, and the inner layer portion 30 and the outer layer portion 40 are formed of three-strand coils.

[0037] As shown in FIG. 5(A), in the longitudinal section of the coil body 100a, the cross-sectional shape of the second metal wire element 24a is rectangular. The flat surfaces of the second metal wire elements 24a adjacent to each other in the radial direction (Y-axis direction) of the coil body 100a face each other. Specifically, the flat surface on the outer peripheral side of the inner second metal wire element 24Aa and the flat surface on the inner peripheral side of the outer second metal wire element 24Ba face each other in the radial direction, and at least a part of them is in contact with each other. Also, the flat surfaces of the second metal wire elements adjacent to each other in the axial direction (Z-axis direction) of the coil body 100a face each other.

[0038] In the longitudinal cross-section of the coil body 100a, the cross-sectional shape of the first metal wire 14a is rectangular. Among the first metal wires 14a, the opposing surfaces with the second metal wires 24a (second metal wire 24Aa, second metal wire 24Ba) adjacent in the axial direction of the coil body 100a are flat surfaces. Specifically, in the axial direction of the coil body 100a, the flat surface located at the end of the first metal wire 14a faces the flat surface of the second metal wire 24Aa located at the end of the inner layer portion 30, and at least a part of them are in contact. In the axial direction of the coil body 100a, the flat surface located at the end of the first metal wire 14a faces the flat surface of the second metal wire 24Ba located at the end of the outer layer portion 40, and at least a part of them are in contact.

[0039] As shown in FIG. 5(B), the coil body 100b of the comparative example does not include the second spiral portion 20a and has a configuration in which only the first spiral portion 10a (first metal wire 14a) is tightly wound. The thickness D1 of the coil body 100a of the second embodiment is the same as the thickness D5 of the coil body 100b of the comparative example. For samples of such a coil body 100a of the second embodiment and the coil body 100b of the comparative example, the maximum torque and flexibility were evaluated.

[0040] Regarding the maximum torque, in a known torsion test, one end of each sample was fixed, the other end was rotated to apply a torsional force, and the torsional force (mNm) when each sample broke was measured and evaluated. As a result, for the coil body 100a of the second embodiment, it was 0.4957 (mNm), and for the coil body 100b of the comparative example, it was 0.4331 (mNm), and the maximum torques of both were about the same. Regarding flexibility, in a known three-point bending test, a bending load was applied to each sample, and the bending load (N / m) when each sample began to bend was measured and evaluated. As a result, for the coil body 100a of the second embodiment, it was 0.007754 (N / m), and for the coil body 100b of the comparative example, it was 0.011574 (N / m), and the coil body 100a of the second embodiment had higher flexibility than the coil body 100b of the comparative example. From these evaluation results, it can be seen that the coil body 100a of the second embodiment can improve flexibility while maintaining the thickness and maximum torque compared to the coil body 100b of the comparative example.

[0041] In the longitudinal section of the coil body 100a, the cross-sectional shape of the second metal wire 24a is rectangular. The flat surfaces of the second metal wires 24a adjacent to each other in the radial direction (Y-axis direction) of the coil body 100a face each other (see Fig. 5(A)). For this reason, the positional relationship between the adjacent second metal wires 24a is stable. Therefore, according to the present embodiment, for example, compared with a configuration in which the cross-sectional shape of the second metal wire 24a is circular, it is possible to suppress the occurrence of problems such as the outer second metal wire 24Ba entering between the inner second metal wires 24Aa.

[0042] In the longitudinal section of the coil body 100a, the cross-sectional shape of the first metal wire 14a is rectangular. Among the first metal wires 14a, the opposing surfaces with the second metal wires 24a (second metal wire 24Aa, second metal wire 24Ba) adjacent to each other in the axial direction of the coil body 100a are flat surfaces. According to the present embodiment, for example, compared with a configuration in which the cross-sectional shape of the first metal wire 14a is circular, it is possible to suppress the displacement of the position of the second metal wire 24a with respect to the first metal wire 14a. For example, it is suppressed that the second metal wire 24a rides on the outside of the first metal wire 14a or enters the inside thereof.

[0043] C. Modification example: The present invention is not limited to the above-described embodiments, and can be implemented in various aspects without departing from the gist thereof. For example, the following modifications are also possible.

[0044] In each of the above embodiments, the coil bodies 100 and 100a have a configuration including two spiral portions (first spiral portions 10 and 10a, second spiral portions 20 and 20a) having different numbers of wires and layers from each other, but a configuration including three or more spiral portions having different numbers of wires and layers from each other may also be used. The first spiral portions 10 and 10a have a configuration having a pair of first divided portions 12 and 12a, but may have one or three or more first divided portions 12 and 12a. The second spiral portions 20 and 20a have a configuration having a pair of second divided portions 22 and 22a, but may have one or three or more second divided portions 22 and 22a. Further, in the above embodiment, an example is shown in which the number Q of the second metal wires forming the second spiral portion is larger than the number P of the first metal wires forming the first spiral portion, but the present invention is not limited thereto, and the number Q of the second metal wires forming the second spiral portion (for example, 2 wires × 2 layers) may be the same as or smaller than the number P of the first metal wires forming the first spiral portion (for example, 8 wires × 1 layer).

[0045] In each of the above embodiments, the first divided portions 12, 12a are single-layer coils formed by spirally winding a single first metal wire 14, but they may also be multi-layer coils or multi-strand coils formed by spirally winding a plurality of first metal wires 14. In short, the number P of the first metal wires 14, 14a forming the first spiral portions 10, 10a may be 1 or 3 or more, and the number of layers M of the first spiral portions 10, 10a may be 2 or more.

[0046] In each of the above embodiments, the thickness D3 of the inner second metal wires 24A, 24Aa may be thinner or thicker than the thickness D4 of the outer second metal wires 24B, 24Ba. The width W2 of the outer second metal wires 24B, 24Ba may be the same as or narrower than the width W3 of the inner second metal wires 24A, 24Aa. The thickness D1 of the first spiral portions 10, 10a may be thinner or thicker than the thickness of the second spiral portions 20, 20a.

[0047] In the first embodiment above, the first metal wire 14 and the second metal wire 24 are round wires, but not limited thereto, and the cross-sectional shape perpendicular to the axial direction of each wire may be a rectangular flat wire, a polygonal wire, an elliptical wire, etc. The number Q of the second metal wires 24 forming the second spiral portion 20 may be a plurality of wires other than 16, and the number of layers N of the second spiral portion 20 may be 3 or more.

[0048] In the second embodiment above, the first metal wire 14a and the second metal wire 24a are flat wires, but not limited thereto, and the cross-sectional shape perpendicular to the axial direction of each wire may be a circular round wire, a polygonal wire, an elliptical wire, etc. The number Q of the second metal wires 24a forming the second spiral portion 20a may be a plurality of wires other than 12, and the number of layers N of the second spiral portion 20a may be 3 or more.

[0049] The coil bodies 100, 100a of the above embodiments are formed in a hollow cylindrical shape, but are not limited thereto, and may be formed to have a hollow portion in a shape such as an elliptical column or a polygonal column.

[0050] In the coil body 100 of the above embodiment, the forming materials of the first spiral portion 10 and the second spiral portion 20 can be appropriately selected.

[0051] The manufacturing method of the coil body 100 of the above embodiment is not limited to the above-described manufacturing method.

Explanation of Reference Numerals

[0052] 10, 10a: First spiral portion 10, 20: Spiral portion 10, 10a: First spiral portion 12, 12a: First divided portion 14, 14a: First metal wire 20, 20a: Second spiral portion 22, 22a: Second divided portion 24, 24a, 24A, 24Aa, 24B, 24Ba: Second metal wire 30: Inner layer portion 40: Outer layer portion 100, 100a, 100b: Coil body L: Central axis

Claims

1. A coil body formed by spirally winding a metal wire, a first spiral portion of M (where M≧1) layers formed by the first metal wire of P (where P≧1) books, and a second spiral portion of N (where N>M) layers formed by Q (where Q≧2) second metal wires having at least a smaller dimension in the radial direction of the coil body than the first metal wire, in the first spiral portion, a spiral gap is formed between adjacent first metal wires spaced apart in the axial direction of the coil body, and the second spiral portion is disposed so as to be interposed in the gap. Coil body.

2. The coil body according to claim 1, the cross-sectional shape perpendicular to the axial direction of the second metal wire is rectangular, and the flat surfaces of the second metal wires adjacent to each other in the radial direction of the coil body face each other. Coil body.

3. The coil body according to claim 1 or claim 2, the cross-sectional shape perpendicular to the axial direction of the first metal wire is rectangular, and among the first metal wires, the opposing surface to the second metal wire adjacent to each other in the axial direction of the coil body is a flat surface. Coil body.

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