Twisted conductor, electric wire and method for manufacturing twisted conductor

Abstract

To provide a twisted conductor and an electric wire which can suppress complication of a structure while improving peeling processability, and a method for manufacturing a twisted conductor which can suppress complication of manufacture while improving peeling processability.SOLUTION: A twisted conductor 10 includes first conductor parts C1 and second conductor parts C2. The first conductor parts C1 are constituted so as to form a plurality of layers from inside of a plurality of conductors 11 having the same diameter, have contours having approximately regular polygons in a cross-sectional view, and the respective conductors 11 in at least the outermost layer have contact relations with the adjacent conductors 11. The second conductor parts C2 are constituted of fine conductors 12 which are arranged in gap parts positioned outside among the outermost conductors 11 which constitute the first conductor parts C1 and have the contact relations, and have diameters smaller than those of the conductors 11 constituting the first conductor parts C1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stranded conductor, an electric wire, and a method for manufacturing a stranded conductor. [Background technology]

[0002] Conventionally, a stranded conductor, such as a seven-core conductor, has been proposed, which is composed of one central conductor and six other conductors twisted around it. When viewed in cross section, such a stranded conductor has an external shape that is approximately a regular polygon (approximately a regular hexagon in the case of a seven-core conductor). For this reason, an electric wire in which such a stranded conductor is covered with an insulation has a thick insulation at the sides of the polygon and a thin insulation at the vertices of the polygon. As a result, the insulation at the sides is likely to remain when the wire is stripped.

[0003] In view of this, a stranded conductor has been proposed in which conductors of different diameters are used so that the outer shape is close to a perfect circle (see, for example, Patent Documents 1 to 7). With this stranded conductor, the outer shape in cross section is close to a perfect circle rather than a regular polygon, which makes it less likely that insulation will remain on the edges when stripped, improving stripping workability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-317477 A [Patent Document 2] JP 2009-140661 A [Patent Document 3] JP 2009-54410 A [Patent Document 4] JP 2012-119073 A [Patent Document 5] JP 2020-13686 A [Patent Document 6] JP 2020-198263 A [Patent Document 7] Patent Publication No. 2021-64475 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the stranded conductors described in Patent Documents 1 to 7, conductors with different diameters are twisted together adjacent to each other so that the outermost layer has a substantially perfect circular shape in cross section. For this reason, the stranded conductors described in Patent Documents 1 to 7 require the conductors with different diameters to be twisted together at the same time, which tends to complicate the structure and manufacturing process.

[0006] The present invention has been made to solve these conventional problems, and an object of the present invention is to provide a stranded conductor and electric wire that can improve stripping processability while preventing the structure from becoming complicated, and a manufacturing method for a stranded conductor that can improve stripping processability while preventing the manufacturing process from becoming complicated. [Means for solving the problem]

[0007] The stranded conductor of the present invention is formed in multiple layers from the inside out using multiple conductors of the same diameter, has an approximately regular polygonal outer shape when viewed in cross section, and comprises: a first conductor portion in which each conductor in at least the outermost layer is in contact with an adjacent conductor; and a second conductor portion arranged in a gap portion located on the outside between the conductors in the outermost layer in contact with each other that constitute the first conductor portion, and constituted by a thin conductor having a smaller diameter than the conductors that constitute the first conductor portion.

[0008] An electric wire according to the present invention includes the above-described stranded conductor and an insulator covering the stranded conductor and having a cross-sectional outer shape that is substantially circular.

[0009] A manufacturing method of a stranded conductor according to the present invention includes a first step of twisting a plurality of conductors of the same diameter to form a first conductor portion having a plurality of layers from the inside, an outer shape of a substantially regular polygon when viewed in cross section, and each conductor in at least the outermost layer being in contact with an adjacent conductor; and a second step of forming a second conductor portion by arranging a thin conductor having a smaller diameter than the conductors constituting the first conductor portion in the gap portions located on the outside between the conductors in the outermost layer that are in contact with each other and constitute the first conductor portion. Effect of the Invention

[0010] According to the present invention, it is possible to provide a stranded conductor and an electric wire that can improve stripping processability while suppressing the complexity of the configuration, and a manufacturing method for a stranded conductor that can improve stripping processability while suppressing the complexity of manufacturing. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing an electric wire according to an embodiment of the present invention. [Diagram 2] 1 is a table showing an example of an electric wire etc. according to an embodiment of the present invention. [Diagram 3] 2A to 2C are cross-sectional views showing manufacturing steps of the electric wire shown in FIG. 1, where (a) shows a first step, (b) shows a second step, and (c) shows a third step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and can be modified as appropriate within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are appropriately applied to the details of the omitted technologies within the scope of the contents described below.

[0013] 1 is a cross-sectional view showing an electric wire according to an embodiment of the present invention. As shown in FIG 1, the electric wire 1 according to the present embodiment is configured to include a stranded conductor 10 and an insulator 20.

[0014] The stranded conductor 10 is a conductor portion formed by twisting a conductor 11 and a thin conductor 12. The conductor 11 and the thin conductor 12 are formed of, for example, a metal such as copper or aluminum, an alloy of these metals, or a metal-plated version of these. The conductor 11 and the thin conductor 12 may be formed of a single wire, or may be formed of a twisted wire formed by twisting metal wires or the like. Such a stranded conductor 10 includes a first conductor portion C1 formed of the conductor 11 and a second conductor portion C2 formed of the thin conductors 12.

[0015] The first conductor portion C1 is formed by twisting a plurality of conductors 11 (seven conductors in the example shown in FIG. 1) having the same diameter from the inside to form a plurality of layers (two layers in the example shown in FIG. 1). As shown by the dashed dotted line in FIG. 1, the first conductor portion C1 has an outer shape of a substantially regular polygon (substantially a regular hexagon in the example shown in FIG. 1) in cross section. Furthermore, in the first conductor portion C1, at least in the outermost layer (in the second layer in the example shown in FIG. 1), each conductor 11 is in contact with the adjacent conductor 11.

[0016] The second conductor portion C2 is composed of a plurality of thin conductors 12 (six in the example shown in FIG. 1) each having a smaller diameter than the conductor 11 constituting the first conductor portion C1. The plurality of thin conductors 12 also have the same diameter.

[0017] The thin conductors 12 are arranged in gaps between the conductors 11 that are in contact with each other. More specifically, the thin conductors 12 are arranged in gaps located on the outside between the conductors 11 in the outermost layer (the second layer from the inside in the example shown in FIG. 1). As a result, the thin conductors 12 are arranged from the outside at the sides of the first conductor portion C1 that is a substantially regular polygon in cross section.

[0018] Furthermore, the thin conductors 12 have a diameter that is approximately inscribed in the circumscribing circle of the first conductor portion C1. This results in the stranded conductor 10 having an approximately perfect circular shape in cross section as shown by the dashed line in Fig. 1. Here, "approximately inscribed" refers to a state in which the thin conductors 12 are spaced apart inward from the circumscribing circle by, for example, 10% or less of the diameter of the thin conductors 12, or protrude outward.

[0019] The insulator 20 covers the stranded conductor 10. The insulator 20 is made of, for example, PP (Polypropylene), PE (Polyethylene), PVC (Poly Vinyl Chloride), or the like. Here, the insulator 20 according to this embodiment has a cross-sectional outer shape that is substantially circular (for example, the difference between the maximum diameter and the minimum diameter is 10% or less). As described above, the stranded conductor 10 has a substantially circular cross-sectional shape. Therefore, in the electric wire 1 according to this embodiment, there is no significant difference in the thickness of the insulator 20 at any point, and the thickness of the insulator is made uniform, thereby improving the stripping ability.

[0020] Furthermore, in the present embodiment, the stranded conductor 10 has a configuration in which the second conductor portion C2 is arranged to fill in the sides of the first conductor portion C1, which is a substantially regular polygon, and therefore the first conductor portion C1 is used as a base and the second conductor portion C2 is added. Therefore, compared to Patent Documents 1 to 7, in which conductors of different diameters are regularly arranged in the outermost layer to form a perfect circle, the configuration is less complicated.

[0021] Fig. 2 is a diagram showing an example of an electric wire 1 etc. according to an embodiment of the present invention. The electric wire 1 shown in Fig. 2 is merely an example of each size etc., and the electric wire 1 is not limited to that shown in Fig. 2. In addition, Fig. 2 also shows an electric wire 100 according to a comparative example for comparison.

[0022] First, the conductor size of both the electric wires 1 and 100 is 10 sq. Here, the electric wire 100 according to the comparative example has a conductor portion formed by twisting 7 conductors each made of 27 strands of wires each having a diameter of 0.26 mm. In the electric wire 100 according to the comparative example, the conductor portion (stranded conductor) has a regular hexagonal shape.

[0023] In contrast, in the electric wire 1 according to this embodiment, the first conductor portion C1 (see FIG. 1) is formed by twisting seven conductors 11 (see FIG. 1), each of which is formed by twisting 19 wires having a diameter of 0.26 mm. Furthermore, the second conductor portion C2 (see FIG. 1) is formed by twisting six thin conductors 12 (see FIG. 1), each of which is formed by twisting three wires having a diameter of 0.26 mm, so as to fill the sides of the first conductor portion C1. In the electric wire 1 according to this embodiment, the twisted conductor 10 (see FIG. 1) is substantially circular.

[0024] In such an electric wire 1,100, the conductor outer diameter (outer diameter based on the distance between opposing sides) is about 4.5 mm in the comparative example and about 4.06 mm in the embodiment. Also, the outer diameter of one conductor (outer diameter of the primary twist) is about 1.67 mm in the comparative example, and in the embodiment, the large diameter (conductor 11) is about 1.426 mm and the small diameter (thin conductor 12) is about 0.505 mm.

[0025] Furthermore, the thickness of the insulator (thickness on the sides) in the electric wire 1,100 is 1.0 mm in both cases. The finished outer diameter of the electric wire 1,100 itself is 6.5 mm in the comparative example and 6.06 mm in the embodiment.

[0026] The weight of the insulator is 25.1 g / m in the comparative example and 21.2 g / m in the embodiment. The cross-sectional area of ​​the insulator is 20.3 mm 2 In the embodiment, it is 17.1 mm 2 In addition, the groove insulator on the inside of the circumscribing circle of the conductor in the comparative example has a cross-sectional area of ​​2.99 mm 2 The groove insulator on the inside of the circumscribing circle of the stranded conductor 10 according to this embodiment has a cross-sectional area of ​​1.16 mm 2 It is.

[0027] Moreover, the conductor portion according to the comparative example has an outer circumferential diameter (the circumscribed circle length) of 20.7 mm, while the stranded conductor 10 according to the embodiment has an outer circumferential diameter of 18.6 mm.

[0028] Comparing the above embodiment and the comparative example, although the conductor size is 10 sq. in both cases, the embodiment has reduced the conductor outer diameter, finished outer diameter, insulator weight, insulator cross-sectional area, groove insulator cross-sectional area, and conductor circumferential outer diameter by about 9.8%, about 6.8%, about 15.8%, about 15.8%, about 61.1%, and about 10.3%, respectively. In other words, the electric wire 1 according to the embodiment also contributes to reducing the diameter of the electric wire and the amount of insulator used.

[0029] FIG. 3 is a process diagram showing the method for producing the electric wire 1 according to this embodiment, where (a) shows a first process, (b) shows a second process, and (c) shows a third process.

[0030] 3(a), the first conductor portion C1 is formed in the first step. In this first step, a plurality of conductors 11 having the same diameter are twisted together so that the outer shape is a substantially regular polygon in cross section. In this first step, the plurality of conductors 11 are twisted from the inside to form a plurality of layers, and at least in the outermost layer, each conductor 11 is in contact with adjacent conductors 11 in the same layer.

[0031] Next, as shown in Fig. 3(b), the second conductor portion C2 is formed in the second step to produce the stranded conductor 10. In the second step, thin conductors 12 having a smaller diameter than the conductors 11 are additionally stranded. In this second step, the thin conductors 12 are arranged in the gaps located on the outside between the conductors 11 in the outermost layer that constitutes the first conductor portion C1. In particular, as a result of the additional arrangement of the thin conductors 12 in the second step, the outer shape of the stranded conductor 10 is made to be substantially circular when viewed in cross section.

[0032] Next, as shown in Fig. 3(c), in the third step, the stranded conductor 10 is covered with the insulator 20 by extrusion or the like. The insulator 20 is applied to cover the stranded conductor 10 so that the outer shape of the insulator 20 becomes substantially circular. In this way, the electric wire 1 having a uniform insulation thickness is manufactured.

[0033] In this way, the stranded conductor 10 according to the present embodiment has a first conductor portion C1 having an approximately regular polygonal outer shape in cross section made up of multiple conductors 11 of the same diameter, and a second conductor portion C2 made up of thin conductors 12 arranged in the outer gaps between the conductors 11 of the outermost layer that are in contact with each other and constitute the first conductor portion C1. Therefore, the approximately regular polygonal first conductor portion C1 is used as a base, and the second conductor portion C2 is formed from the outside so as to fill in its sides. This makes it possible to reduce the complexity of the configuration compared to a case in which conductors of different diameters are regularly arranged in the outermost layer to form a perfect circle. Therefore, it is possible to reduce the complexity of the configuration while improving the peelability.

[0034] Furthermore, the second conductor portion C2 has a diameter that is approximately inscribed in the circumscribing circle of the first conductor portion C1 when viewed in cross section. Therefore, by using the regular polygon shape of the first conductor portion C1 as a basis and simply adjusting the diameter of the thin conductors 12 of the second conductor portion C2, it is possible to make the twisted conductor 10 closer to a perfect circle, thereby further improving the strippability while preventing the configuration from becoming too complicated.

[0035] Furthermore, according to the electric wire 1 of this embodiment, since it comprises the above-mentioned twisted conductor 10 and the insulator 20 that covers the twisted conductor 10 and has a cross-sectional outer shape that is approximately circular, it is possible to provide an electric wire 1 in which the thickness of the insulator 20 is made uniform.

[0036] In addition, the manufacturing method of the stranded conductor 10 according to the present embodiment includes a first step of forming a first conductor portion C1 having an approximately regular polygonal outer shape in cross section by using a plurality of conductors 11 of the same diameter, and a second step of forming a second conductor portion C2 by arranging thin conductors 12 in the outer gaps between the conductors 11 of the outermost layer that are in contact with each other and constitute the first conductor portion C1. Therefore, the approximately regular polygonal first conductor portion C1 is used as a base, and the second conductor portion C2 is formed from the outside so as to fill its sides. This eliminates the need to simultaneously twist conductors of different diameters together for the outermost layer, and thus reduces the complexity of the manufacturing process. Therefore, it is possible to improve the peeling ability while reducing the complexity of the manufacturing process.

[0037] The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment, and modifications may be made without departing from the spirit of the present invention, and if possible, known or well-known technologies may be combined.

[0038] For example, in this embodiment, the thin conductor 12 has a diameter that is approximately inscribed in the circumscribing circle of the first conductor portion C1, but this is not particularly limited, and for example, a thin conductor 12 having a diameter that does not extend beyond the circumscribing circle may be arranged. Furthermore, the thin conductor 12 may have a diameter that exceeds the circumscribing circle. In this case, the thin conductor 12 is considered to have a diameter that contributes to the uniformity of the insulator thickness. Specifically, the diameter that contributes to the uniformity is (insulator thickness at the sides assuming that the thin conductor 12 does not exist) - (insulator thickness at the vertices of the approximate polygon) > (distance of the thin conductor 12 that extends outside the circumscribing circle).

[0039] In addition, in this embodiment, the thin conductors 12 have the same diameter, but this is not limited to the same diameter. For example, in this embodiment, the number of conductors 11 is seven, so one thin conductor 12 is arranged on each side of the polygon, but depending on the number of conductors 11, three or more thin conductors 12 may be arranged on each side. In this case, making the diameters of the thin conductors 12 different makes it easier to make the stranded conductor 10 closer to a perfect circle. [Explanation of symbols]

[0040] 1:Electric wire 10: Stranded conductor 11: Conductor 12: Thin conductor 20: Insulator C1: First conductor section C2: Second conductor section

Claims

1. a first conductor portion which is formed from an inner side in a plurality of layers of conductors having the same diameter, has a substantially regular polygonal outer shape in cross section, and in which each conductor in at least the outermost layer is in contact with an adjacent conductor; a second conductor portion disposed in a gap portion located on the outside between the conductors of the outermost layer that are in contact with each other and that constitute the first conductor portion, the second conductor portion being made of a thin conductor having a smaller diameter than the conductor that constitutes the first conductor portion; A stranded conductor comprising:

2. The second conductor portion has a diameter that is approximately inscribed in a circumscribing circle of the first conductor portion in a cross-sectional view. The stranded conductor according to claim 1 .

3. The stranded conductor according to claim 1 ; an insulator covering the stranded conductor and having a cross-sectional outer shape that is substantially circular; An electric wire comprising:

4. a first step of twisting a plurality of conductors having the same diameter to form a first conductor portion having a plurality of layers from the inside, a substantially regular polygonal outer shape in cross section, and each conductor in at least the outermost layer being in contact with an adjacent conductor; a second step of forming a second conductor by arranging a thin conductor having a smaller diameter than the conductor constituting the first conductor in a gap portion located on the outside between the conductors of the outermost layer that are in contact with each other and constitute the first conductor; A method for manufacturing a stranded conductor comprising:

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