JP2018063833A - coaxial cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coaxial cable provided with a conductor having a thin diameter, and excellent flexibility.SOLUTION: A coaxial cable includes: an inner conductor; an insulator layer provided so as to surround a side periphery of the inner conductor; and an outer conductor provided so as to surround the side periphery of the insulator layer, in which the inner conductor is provided with a tensile braided wire obtained by braiding a plurality of tensile wires and a plurality of conductive wires provided on a circumference concentric with tensile braided wires so as to surround the side periphery of the tensile braided wire and obtained by braiding with the tensile braided wire at a center.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a coaxial cable.

  Conventionally, when transmitting an electric signal, a coaxial cable having an inner conductor, an insulating layer, an outer conductor, and a sheath has been used. The inner conductor is a stranded wire formed by twisting a high-tensile metal wire made of CP wire and a low-resistance metal wire made of annealed copper wire so as to enclose the side circumference of the high-tensile metal wire, It has been proposed to use a stranded wire (compressed stranded wire) that has been compressed so that the wire has a predetermined diameter (see, for example, Patent Document 1).

JP-A-8-2222036

  However, although the above-described compression twisted wire can make the inner conductor small (thin diameter), the CP wire is a wire having low bending resistance. It may break.

  An object of the present invention is to provide a coaxial cable including a conductor having a small diameter and good bending resistance.

According to one aspect of the invention,
An inner conductor, an insulating layer provided so as to surround a side circumference of the inner conductor, and an outer conductor provided so as to surround a side circumference of the insulating layer,
The inner conductor is
A tensile stranded wire formed by twisting a plurality of tensile strength wires;
A coaxial cable having a plurality of conductive wires arranged on a circumference concentric with the tensile strength stranded wire and twisted around the tensile strength stranded wire so as to surround a side circumference of the tensile strength stranded wire over the entire circumference. Is provided.

  ADVANTAGE OF THE INVENTION According to this invention, a coaxial cable provided with the conductor which is small diameter and has favorable bending resistance can be provided.

It is a figure which shows an example of the schematic sectional drawing in the radial direction of the coaxial cable concerning one Embodiment of this invention. (A) is a figure which shows an example of the schematic sectional drawing in the radial direction of the internal conductor with which the coaxial cable of FIG. 1 is provided, (b) is a figure which shows an example of the schematic sectional drawing in the radial direction of the conventional internal conductor. (C) is a figure which shows the other example of the schematic sectional drawing in the radial direction of the conventional internal conductor. It is a figure which shows the schematic diagram explaining the twist pitch of an electroconductive wire (tensile strength strand wire). It is a figure explaining the method of a bending test.

<One Embodiment of the Present Invention>
(1) Configuration of Coaxial Cable A configuration of a coaxial cable according to an embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the coaxial cable 1 according to this embodiment includes an inner conductor (center conductor) 2, an insulating layer 3 provided so as to surround the side periphery of the inner conductor 2, and a side periphery of the insulating layer 3. The outer conductor 4 is provided so as to surround the outer conductor 4 and the outer sheath (sheath) 5 is provided so as to surround the side periphery of the outer conductor 4.

  For example, as shown in FIG. 2A, the inner conductor 2 included in the coaxial cable 1 includes a tensile strength strand 22 formed by twisting a plurality of (for example, 19 in this embodiment) strength wires 21, and a strength strand 22. And a plurality of conductive wires 23 provided so as to surround the entire circumference of the side.

  The tensile strength stranded wire 22 has a plurality of layers composed of the tensile strength wires 21. That is, the tensile strength stranded wire 22 according to the present embodiment includes a first layer composed of a single tensile strength wire 21a arranged at the center of the tensile strength stranded wire 22 and a first layer as shown in FIG. A second layer composed of a plurality of (for example, six) tensile wires 21b arranged so as to surround the side periphery, and a plurality of (for example, twelve) tensile wires 21c arranged so as to surround the side periphery of the second layer. And a third layer.

  The tensile strength stranded wire 22 desirably has a breaking strength of, for example, 1500 MPa or more. Thereby, even when a plurality of conductive wires 23 are arranged on the side periphery of the tensile strength stranded wire 22, the breaking strength of the entire inner conductor 2 can be set to 450 MPa or more, preferably about 1000 MPa, and a predetermined bending resistance is ensured. it can. In addition, when the breaking strength of the tensile strength stranded wire 22 is less than 1500 MPa, the breaking strength of the entire inner conductor 2 may be less than 450 MPa.

  In place of the above-described tensile strength stranded wire 22, it is also conceivable to use a single tensile strength wire having a predetermined diameter, that is, a single wire having a tensile strength (for example, a SUS wire). However, in this case, when the inner conductor 2 (coaxial cable 1) is bent, the amount of bending strain applied to the bent portion of the tensile strength wire is larger than that of the tensile strength twisted wire 22. Therefore, predetermined bending resistance (bending resistance) may not be ensured. Moreover, although the improvement of bending resistance is recognized as the breaking strength of the SUS wire increases, the present inventor has confirmed that the predetermined bending resistance cannot be secured.

  As the tensile wire 21, a wire formed of a material having a lower conductivity than the conductive wire 23 can be used. For example, a strand made of stainless steel (SUS) can be used as the tensile strength wire 21. That is, a SUS rope can be used as the above-mentioned tensile strength stranded wire 22. Moreover, the strand (steel wire, piano wire) made of steel can also be used as the tensile strength wire 21. However, SUS strands are preferred in that they are less likely to rust than piano strands. Further, as the tensile strength wire 21, a strand made of a shape memory alloy containing nickel (Ni) or titanium (Ti) can be used. However, SUS strands and piano strands are preferable in terms of lower costs than strands made of the shape memory alloy described above.

  In addition, it is possible to use the thread | yarn which consists of fibers with comparatively high tension, such as an aramid fiber and nylon, as the tensile strength line 21. However, in this case, it is difficult to make the cross-sectional shape in the radial direction of the tensile strength stranded wire 22 circular (for example, a perfect circle), and as a result, the cross-sectional shape in the radial direction of the internal conductor 2 (hereinafter referred to as “the cross-sectional shape of the internal conductor 2”). May also be a circle. Further, the tensile strength twisted wire 22 made of yarn has a problem that when it is repeatedly bent, it is untwisted or difficult to connect to a connector or the like.

  The conductive line 23 is a line for signal transmission (signal transmission). The plurality of conductive wires 23 are, for example, the centers of the respective tensile strength wires 21 constituting the outermost layer of the tensile strength twisted wires 22 (that is, the tensile strength wires 21c constituting the third layer, hereinafter also referred to as “outermost tensile strength wires 21c”). It is distributed on the circumference concentric with the passing circle. The plurality of conductive wires 23 have the same shortest distance between the center of the tensile strength stranded wire 22 and the center of each conductive wire 23, and the adjacent conductive wires 23 are in contact with each other. 22 is arranged so as to contact. The plurality of conductive wires 23 are twisted around the tensile strength stranded wire 22.

  The number of conductive wires 23 is preferably larger than the number of outermost tensile strength wires 21c. For example, when the number of outermost tensile strength wires 21c is 12 as in this embodiment, the number of conductive wires 23 is preferably 13 or more.

  The number of the conductive lines 23 is a number within a range in which a layer (conductive layer) composed of the conductive lines 23 can be accommodated in one layer, and is preferably as large as possible. This is because a signal for high-speed transmission, that is, an electric signal in a high frequency range, mainly flows on the surface side of the inner conductor 2 (conductive layer) due to the skin effect. For example, a signal of 1 GHz band mainly flows in a region from the surface of the inner conductor 2 to a depth of about 1 μm. Therefore, in addition to the fact that there is almost no merit of using a plurality of conductive layers, the diameter (diameter) of the internal conductor 2 is increased by using a plurality of conductive layers, and the coaxial cable 1 may not be reduced in size. Therefore, the number of conductive lines 23 is preferably set to a number within the above range.

  Each conductive wire 23 preferably has a diameter smaller than that of the tensile strength wire 21. Thereby, the number of the conductive wires 23 can be surely increased as compared with the number of the outermost tensile strength wires 21c.

  The diameter of each conductive wire 23 is smaller than that of the tensile strength wire 21 and is preferably as small as possible. Thereby, the surface of the internal conductor 2 can be made as a flat surface with as few irregularities as possible, that is, the cross-sectional shape of the internal conductor 2 can be made close to a circle (perfect circle).

  Moreover, it is preferable that each of the plurality of conductive wires 23 has the same diameter. Thereby, the cross-sectional shape of the internal conductor 2 can be reliably brought close to a circle.

  As the conductive wire 23, for example, a wire formed of a material having higher conductivity than the tensile strength wire 21 such as a copper wire or a copper alloy wire can be used. A copper wire is preferable in that it has a higher electrical conductivity than a copper alloy wire, and a copper alloy wire is preferable in that it has a higher tensile strength than a copper wire. The conductive wire 23 preferably has a conductivity of 85% IACS or more, for example. If the conductivity of the conductive wire 23 is less than 85% IACS, a high-speed signal may not be transmitted or transmission loss may increase.

As described above, the plurality of conductive wires 23 are twisted around the tensile strength twisted wire 22. At this time, the twist rate of the conductive wire 23 and the twist rate of the tensile strength twisted wire 22 are preferably different. That is, it is preferable that each conductive wire 23 intersects each tensile strength line 21 (particularly the outermost tensile strength line 21c). Specifically, the ratio (P ₁ / Pd ₁ ratio) of the twist pitch (P ₁ ) of the conductive wire 23 to the layer core diameter (Pd ₁ ) of the layer composed of the conductive wire 23 and the outermost tensile strength wire 21c The ratio (P ₂ / Pd ₂ ratio) of the twist pitch (P ₂ ) of the outermost tensile strength wire 21c to the layer core diameter (Pd ₂ ) of the layer to be constructed is different (P ₁ / Pd ₁ ratio ≠ P ₂ / Pd ₂ ratio). The layer core diameter of the layer formed of the conductive wire 23 is the diameter of a circle C1 passing through the center of each conductive wire 23 arranged in an annular shape on the side periphery of the tensile strength stranded wire 22, and the outermost tensile strength wire 21c. Is the diameter of the circle C2 passing through the center of each outermost tensile strength line 21c. Further, as shown in FIG. 3, the twist pitch (P ₁ , P ₂ ) means that each conductive wire 23 and each outermost tensile wire 21c each have a central axis m of the coaxial cable 1 (that is, the tensile strand 22). This is the distance required to rotate 360 ° spirally in the circumferential direction as the center.

Moreover, it is preferable that the conductive wire 23 is twisted at a shorter pitch than the outermost tensile strength wire 21c. In other words, the P ₁ / Pd ₁ ratio is preferably smaller than the P ₂ / Pd ₂ ratio (P ₁ / Pd ₁ ratio <P ₂ / Pd ₂ ratio).

Moreover, when the twist direction of the conductive wire 23 and the twist direction of the tensile strength twisted wire 22 are the same direction, the change in the twisted state of the conductive wire 23 due to the bending of the internal conductor 2 (coaxial cable 1) It is preferable at the point which can make it the same tendency as the change of the twist state of. That is, when the twisting of the conductive wire 23 is loosened, the twisting of the tensile wire 21 can be loosened, and when the twisting of the conductive wire 23 is tightened, the twisting of the tensile wire 21 can be tightened. preferable. The change in the twisted state of the conductive wire 23 and the tensile twisted wire 22 means that the conductive wire 23 and the tensile twisted wire 22 are twisted when the inner conductor 2 is bent. ₁ ) and the twist pitch (P ₂ ) of the tensile strength stranded wire 22 is changed.

  Moreover, when the twist direction of the conductive wire 23 and the twist direction of the tensile strength twisted wire 22 are different from each other, it is preferable in that the conductive wire 23 and the outermost tensile strength wire 21c are easily crossed.

  As described above, the insulating layer 3 is provided so as to surround the outer periphery of the inner conductor 2. The insulating layer 3 is preferably formed of a material having a low dielectric constant and a dielectric loss tangent in order to have excellent insulating properties and reliably reduce transmission loss. The insulating layer 3 is preferably formed of an insulating resin such as polytetrafluoroethylene (PTFE), polyethylene, perfluoroalkoxyalkane (PFA). The insulating layer 3 can also be formed of a foamed insulating resin such as foamed polyethylene or foamed fluororesin, whereby the dielectric constant and dielectric loss tangent of the insulating layer 3 can be further reduced.

  As described above, the outer conductor 4 is provided so as to cover the side periphery of the insulating layer 3. The outer conductor 4 functions as a shield layer. The outer conductor 4 is preferably made of a material having high conductivity such as copper or copper alloy. For example, as the outer conductor 4, a braided shield formed by braiding a plurality of copper or copper alloy wires (copper wires or copper alloy wires) in a lattice shape, or a plurality of strands are spirally wound on the insulating layer 3. A transversely wound shield formed by attaching can be used.

  As described above, the sheath 5 is provided so as to cover the side periphery of the outer conductor 4. The sheath 5 is a layer that forms the outermost periphery of the coaxial cable 1 and functions as a protective layer of the coaxial cable 1. The sheath 5 can be formed of polyethylene resin, ethylene-vinyl acetate polymer, fluorine-based resin, silicone-based resin, or the like.

(2) Effects According to the Present Embodiment According to the present embodiment, one or more effects described below are exhibited.

(A) By configuring the inner peripheral side of the inner conductor 2 with the tensile stranded wire 22 and the outer peripheral side with the conductive wire 23, high flexibility is ensured even if the inner conductor 2 is made small (small diameter). can do. In particular, by configuring the inner peripheral side of the inner conductor 2 with the tensile stranded wire 22, higher bending resistance than that of the conventional inner conductor can be ensured.

  When the diameter of the inner conductor 2 is the same, the bending life of the inner conductor 2 according to this embodiment is a copper alloy formed by twisting together a plurality of copper alloy strands as shown in FIG. The inventor of the present application has confirmed that the bending life of the inner conductor 20A made of a stranded wire is longer. The bending life is the number of times the internal conductor is bent until the internal conductor breaks when a bending test is performed on the internal conductor. The larger the number of bending times, the longer the bending life. In the bending test, as shown in FIG. 4, the inner conductor 2 (or the coaxial cable 1 having the inner conductor 2) is arranged vertically, and the inner portion is measured with two jigs 31 having a predetermined radius r and a circular section. After the conductor 2 was sandwiched, for example, the internal conductor 2 was bent by ± 90 ° (left and right) while being pulled with a predetermined load by hanging a weight 32 having a predetermined weight. The number of times of bending was set to 1 by bending left and right once.

  For reference, when the diameter of the inner conductor is the same, the bending life of the above-described inner conductor 20A is greater than the bending life of the inner conductor 20B made of a single copper alloy wire as shown in FIG. 2C, for example. The present inventor has also confirmed that this is long. For example, when the bending life of the above-described inner conductor 20A is 1, the present inventor has confirmed that the bending life of the above-described inner conductor 20B is about 0.2.

(B) By reducing the diameter of each conductive wire 23 or by making each conductive wire 23 the same diameter, the cross-sectional shape of the internal conductor 2 is made close to a circular shape without compressing the conductive wire 23. be able to. Thereby, the loss (transmission loss) of the electric signal flowing through the inner conductor 2 can be reduced.

  The internal conductor 2 according to the present embodiment can reduce transmission loss more than the above-described internal conductor 20A, and can have transmission loss comparable to that of the above-described internal conductor 20B. For example, when the transmission loss of the inner conductor 20A is 1, the transmission loss of the inner conductor 2 according to the present embodiment is about 0.85, and the transmission loss of the inner conductor 20B is about 0.8. This inventor has confirmed that. The inner conductors 2, 20A and 20B have the same diameter.

(C) Further, by reducing the diameter of each conductive wire 23, the amount of bending strain applied to the bent portion of the conductive wire 23 when the inner conductor 2 is bent can be reduced. Further, by setting each conductive wire 23 to the same diameter, when the inner conductor 2 is bent, the specific conductive wire 23 is pressed by another adjacent conductive wire 23 at the bent portion (near the bent portion) and disconnected. This can be suppressed. As a result, the bending resistance of the inner conductor 2 can be further improved.

(D) By setting the ratio P ₁ / Pd ₁ ≠ P ₂ / Pd ₂ , the tensile stranded wire 22 is pulled when the inner conductor 2 is bent, so that it is formed between the adjacent outermost tensile strength wires 21 c. It is possible to prevent the conductive wire 23 from falling into the groove (gap). When the inner conductor 2 is bent in a state where the specific conductive wire 23 is fitted in the above-described groove, the specific conductive wire 23 (for example, the conductive wire 23 fitted in the above-described groove) is replaced with another conductive wire 23 or the outermost tensile strength. Although the wire 21 is compressed by the wire 21 or the like, it may be disconnected, but by setting the ratio P ₁ / Pd ₁ ≠ P ₂ / Pd ₂ , this problem can be solved and disconnection of the conductive wire 23 can be suppressed. That is, the bending resistance of the inner conductor 2 can be further improved.

On the other hand, if the P ₁ / Pd ₁ ratio and the P ₂ / Pd ₂ ratio are the same (P ₁ / Pd ₁ ratio = P ₂ / Pd ₂ ratio), each conductive wire 23 is connected to the outermost tensile strength wire 21c. Since they are arranged in parallel, even when the inner conductor 2 is not bent, the conductive wire 23 may fall into a groove between the adjacent outermost tensile strength wires 21c.

(E) By setting the P ₁ / Pd ₁ ratio <P ₂ / Pd ₂ ratio, the length of the conductive wire 23 positioned on the outer peripheral side of the inner conductor 2 is equal to the tensile strength line positioned on the inner peripheral side of the inner conductor 2. 21 (particularly the outermost tensile strength line 21c). The length of the conductive wire 23 (tensile wire 21) is the length in a direction orthogonal to the radial direction of the conductive wire 23 (strength wire 21). As a result, the internal conductor 2 has a P ₁ / Pd ₁ ratio> P ₂ / Pd ₂ ratio due to the extra length of the conductive wire 23 (the conductive wire 23 is twisted at a longer pitch than the tensile wire 21). Since it becomes easy to bend, the conductive wire 23 becomes more difficult to break.

_(F) P ₁ / Pd 1 ratio _<With P 2 / Pd ₂ ratio, when the inner conductor 2 is bent, the twisted state of the conductive wire 23 and the tensile strength stranded wire 22 (in particular, the outermost strength wires 21c) Even if it changes, it can suppress that the conductive wire 23 falls and fits in the above-mentioned groove | channel. As a result, the effect (d) can be obtained with certainty.

_{Incidentally,} if it is P 1 / Pd _{1 ratio>} P ₂ / Pd 2 ratio, twist pitch of the conductive wire 23 and the tensile strength stranded twisted state conductive wire 23 of 22 and tensile strength stranded 22 _(P 1, P ₂₎ is When the direction changes (direction in which twisting is loosened), the conductive wire 23 may fall and fit into the groove.

(G) Since the conductive layer is composed of a plurality of conductive wires 23, when the internal conductor 2 is bent, the stress applied to each conductive wire 23 at the bent portion can be dispersed. It becomes harder to break.

(H) The adjacent conductive wires 23 are in contact with each other, so that when the internal conductor 2 is bent, the adjacent conductive wires 23 in the internal conductor 2 interfere with each other to prevent the conductive wires 23 from moving. it can. As a result, even if the inner conductor 2 is repeatedly bent, the cross-sectional shape of the inner conductor 2 can be maintained in a nearly circular shape, and the specific conductive wire 23 is sandwiched between, for example, the insulating layer 3 and the outermost tensile strength wire 21c. Thus, disconnection of the conductive wire 23 can be suppressed.

(I) The coaxial cable 1 having the inner conductor 2 according to the present embodiment is particularly effective when used for a cable that transmits a high-speed signal (for example, a signal of 400 MHz or more).

(Other embodiments of the present invention)
As mentioned above, although one Embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the summary, it can change suitably.

  In the above-described embodiment, the case where the tensile strength stranded wire 22 includes three layers including the tensile strength wire 21 has been described as an example, but the present invention is not limited to this. For example, a tensile strand 22 having a first layer composed of one tensile wire 21a and a second layer composed of six tensile wires 21b arranged so as to surround the side periphery of the first layer. Also good. That is, the tensile strength stranded wire 22 only needs to have two or more layers composed of the tensile strength wires 21, and the number of the tensile strength wires 21 constituting each layer is not limited to the number of the above-described embodiments. It can be appropriately changed based on the specifications required for the conductor 2 (coaxial cable 1).

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

[Appendix 1]
According to one aspect of the invention,
An inner conductor, an insulating layer provided so as to surround a side circumference of the inner conductor, and an outer conductor provided so as to surround a side circumference of the insulating layer,
The inner conductor is
A tensile stranded wire formed by twisting a plurality of tensile strength wires;
A plurality of conductive wires that are arranged on a circumference concentric with the tensile strength stranded wire and are twisted around the tensile strength stranded wire so as to surround the entire circumference of the side of the tensile strength stranded wire. A cable is provided.

[Appendix 2]
The coaxial cable according to appendix 1, preferably
The tensile strength wire is a stainless steel wire or a steel wire.

[Appendix 3]
The coaxial cable according to appendix 1 or 2, preferably,
The number of the conductive wires is greater than the number of the tensile wires constituting the outermost periphery of the tensile stranded wire.

[Appendix 4]
The coaxial cable according to any one of appendices 1 to 3, preferably,
The diameter of the conductive wire is smaller than the diameter of the tensile wire.

[Appendix 5]
The coaxial cable according to any one of appendices 1 to 4, preferably,
Each of the plurality of conductive wires has the same diameter.

[Appendix 6]
The coaxial cable according to any one of appendices 1 to 5, preferably,
The ratio (P ₁ / Pd ₁ ratio) of the twist pitch (P ₁ ) of the conductive wire to the layer core diameter (Pd ₁ ) of the layer composed of the conductive wire, and the layer core of the layer composed of the tensile wire The ratio (P ₂ / Pd ₂ ratio) of the twist pitch (P ₂ ) of the tensile wire to the diameter (Pd ₂ ) is different.

[Appendix 7]
The coaxial cable according to appendix 6, preferably,
The ratio (P ₁ / Pd ₁ ratio) of the twist pitch (P ₁ ) of the conductive wire to the layer core diameter (Pd ₁ ) of the layer formed of the conductive wire is the layer core of the layer formed of the tensile wire. It is smaller than the ratio (P ₂ / Pd ₂ ratio) of the twist pitch (P ₂ ) of the tensile strength wire to the diameter (Pd ₂ ).

[Appendix 8]
The coaxial cable according to any one of appendices 1 to 7, preferably,
The twist direction of the tensile strength stranded wire and the twist direction of the conductive wire are the same direction.

[Appendix 9]
The coaxial cable according to any one of appendices 1 to 8, preferably,
The twist direction of the tensile-strength wire is different from the twist direction of the conductive wire.

[Appendix 10]
The coaxial cable according to any one of appendices 1 to 9, preferably,
The breaking strength of the tensile strength stranded wire is 1500 MPa or more.

[Appendix 11]
The coaxial cable according to any one of appendices 1 to 10, preferably,
Used for high-speed signal transmission.

1 Coaxial cable 2 Inner conductor (conductor)
21 (21a-21c) Tensile wire 22 Tensile strand wire 23 Conductive wire

Claims (6)

An inner conductor, an insulating layer provided so as to surround a side circumference of the inner conductor, and an outer conductor provided so as to surround a side circumference of the insulating layer,
The inner conductor is
A tensile stranded wire formed by twisting a plurality of tensile strength wires;
A plurality of conductive wires arranged on a circumference concentric with the tensile strength stranded wire so as to surround the side circumference of the tensile strength stranded wire, and twisted around the tensile strength stranded wire,
Coaxial cable with The coaxial cable according to claim 1, wherein the tensile strength wire is a stainless steel wire or a steel wire. The ratio of the twist pitch of the conductive wire to the layer core diameter of the layer composed of the conductive wire is different from the ratio of the twist pitch of the tensile wire to the layer core diameter of the layer composed of the tensile wire. The coaxial cable according to claim 1 or 2. The ratio of the twist pitch of the conductive wire to the layer core diameter of the layer constituted by the conductive wire is smaller than the ratio of the twist pitch of the tensile wire to the layer core diameter of the layer constituted by the tensile wire. The coaxial cable described in 1. The coaxial cable according to any one of claims 1 to 4, wherein a twist direction of the tensile strength twisted wire and a twist direction of the conductive wire are the same direction. The coaxial cable according to any one of claims 1 to 5, wherein the tensile strength of the tensile strength stranded wire is 1500 MPa or more.

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