JP2001311859A - Self-supporting cable and its aerial wire extending method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability of separating a supporting line part from the cable main body in a parallel self-supporting cable and to manufacture it at a cost lower than that of a stranded self-supporting cable. SOLUTION: The cable main body 7 containing an optical fiber 5 with coating 6 applied is parallel to the supporting line part 3 containing a supporting wire 1 with coating 2 applied; and, a neck part 8 with a thickness of 0.10 mm or less longitudinally connects the main body to the supporting part along the longitudinal direction to form the self-supporting cable 9 and 9'. In addition, this self-supporting cable 9 and 9' are used for aerial cable extension by drawing it out while twisting spirally in the advancing direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a self-supporting cable having one or several optical fibers having a small number of fibers, which is used by being extended overhead, and an overhead extension method using the same.

[0002]

2. Description of the Related Art FIG. 3 shows a self-supporting cable having a small number of optical fibers which is used by being extended overhead.
(A), (B) and those having a cross-sectional shape shown in FIG. 3 and 4, reference numeral 21 denotes a support wire, 22 denotes a cover of the support wire portion, 23 denotes a support wire portion, 24 denotes a tensile strength member, 25 denotes an optical fiber, 26 denotes a cover of a cable body portion, 26a denotes a notch,
7 is a cable body, 28 is a neck, 29, 29 ', 30
Is a self-supporting cable.

A self-supporting cable 29 shown in FIG.
Is a supporting wire portion 23 in which a coating 22 made of vinyl chloride resin or the like is applied to a supporting wire 21 made of a steel wire having an outer diameter of about 1.2 mm, and a tensile strength made of two steel wires having an outer diameter of about 0.4 mm. The body 24 and an optical fiber 25 in which a single wire is coated on a single glass fiber and a cable main body 27 in which a coating 26 made of a vinyl chloride resin or the like is provided in parallel with each other. It is connected by a neck 28 made of vinyl resin or the like.

A self-supporting cable 29 'shown in FIG. 3 (B) has two optical fibers 25 instead of one in the self-supporting cable 29 described above. The notch 26a is provided to make it easy to take out the optical fiber 25 from the cable main body 27. In addition, the self-supporting cable of these forms is provided with an extruder for covering the support wire portion 22 with the extruder so as to cover the support wire, the strength member and the optical fiber in parallel while simultaneously supplying them. It is manufactured by simultaneously extruding and coating a vinyl chloride resin or the like that forms the coating 26 of the part and the neck part 28.

A self-supporting cable 30 shown in FIG.
Is formed from two steel wires having an outer diameter of about 0.4 mm around a support wire portion 23 formed by coating a support wire 21 made of a steel wire having an outer diameter of about 2.6 mm with a coating 22 made of vinyl chloride resin or the like. Cable main body 2 having a coating 26 made of vinyl chloride resin or the like made in parallel with a tensile strength member 24 and an optical fiber 25 formed by coating a wire on a single glass fiber.
7 are twisted in plurality. In FIG. 4, 8
Although the two cable main bodies 27 are twisted around the support wire section 23, there are also cable numbers other than eight.

[0006]

In the case of the self-supporting cables 29 and 29 'shown in FIGS. 3A and 3B, the support wire 23 and the cable main body 27 are parallel and the neck 28
Therefore, it is necessary to prevent the connection by the neck portion 28 from being detached so that the cable main body portion 27 does not separate from the support wire portion 23 and hang down in an imaginary extended state. . For this reason, even when a self-supporting cable is passed through a gold wheel or the like for extending the wire imaginarily while applying a tensile tension for the wire extension, the neck 8 is so bent that the neck 28 is not torn by ironing with the wheel. Must have strength. Therefore, the thickness of the neck portion 28 made of vinyl chloride resin is manufactured with a certain value or more,
Even in a cable having a small and light optical fiber with a small number of cores, the thickness of the neck is 0.11 mm or more.

[0007] On the other hand, in the case where a self-supporting cable that is imaginarily extended is drawn down to a customer or the like, it is necessary to separate the cable main body from the supporting wire at an intermediate portion of the cable. However, if the neck is too thick to cut it and separate the support wire from the cable body,
It is necessary to carefully separate them with a knife or the like, which takes time and effort.

The self-supporting cable 30 shown in FIG.
In the case of, the cable main body 27 is twisted around the support wire 23 and there is no connecting portion corresponding to the neck, so that the cable main body is separated from the support wire even in the middle part of the cable. The work is easy. But,
In the case of this twisted type self-supporting cable, the manufacturing process of separately applying the coating of the support wire portion and the coating of the cable main portion to form an independent support wire portion and the cable main portion and twisting them together is performed. is necessary. Therefore, when compared with the parallel type self-supporting cable of the embodiment of FIG. 3, the twisted self-supporting cable of the embodiment of FIG. Manufacturing costs increase.

The present invention improves the workability of separating the supporting wire portion and the cable main body in the case of the above-mentioned parallel type self-supporting cable according to the prior art, and the cable main body hangs down when the cable is extended aerial. The present invention also provides a self-supporting cable that is less expensive than a twisted-type self-supporting cable and an overhead wire drawing method using the same.

[0010]

According to the self-supporting cable of the present invention, the cable body containing the optical fiber and being coated is parallel to the supporting wire where the supporting wire is coated. , Connected by a neck having a thickness of 0.10 mm or less along the longitudinal direction. This self-supporting cable has a neck portion as thin as 0.10 mm or less, so that the supporting wire portion and the cable main body portion can be easily separated even in the middle portion of the cable.

[0011] In addition, the overhead extension method of a self-supporting cable according to the present invention uses the above-described self-supporting cable and twists the cable in the traveling direction to perform the extension. . Thus, even if a force such as ironing is applied to the cable when the overhead wire extends through the wheel and the neck portion between the support wire portion and the cable body portion is torn and separated, the support wire is twisted when the cable is extended and the support wire is twisted. Since the cable body and the cable body are twisted together, there is no problem that the cable body is separated from the support wire and the cable body hangs down when the cable is imaginarily extended between utility poles. . Also, at the time of cable manufacture, the support wire and the cable main body are parallel, so that the coating of the support wire, the coating of the cable main body, and the neck can be provided simultaneously at the same time. The manufacturing cost can be reduced as compared with the support type cable.

[0012]

1 (A) and 1 (B) are perspective views showing an embodiment of a self-supporting cable according to the present invention. Is a support wire portion, 4 is a tensile member, 5 is an optical fiber, 6 is a coating of a cable body, 6a is a notch, 7 is a cable body, 8 is a neck, 9, 9 'are self-supporting cables, and t is a neck. Is the thickness.

The support wire 1 is made of steel wire, galvanized steel wire, or the like, and has an outer diameter of about 1 mm to 3 mm. The tensile strength member 4 is made of a steel wire, a galvanized steel wire, or a coating thereof, and has an outer diameter of about 0.3 mm to 1.0 mm. The optical fiber is obtained by coating a glass fiber or a plastic fiber with a resin wire. In addition, the covering 2 of the supporting wire portion and the covering 6 of the cable main body portion.
The neck 8 is made of a plastic resin such as a vinyl chloride resin. In the case of the self-supporting cable 9 shown in FIG. 1 (A), the support wire 1, the two strength members 4 and the optical fiber 5 are supplied in parallel to an extruder, and the support wire portion is covered so as to cover them. 2 and a plastic resin to be a cover 6 of the cable main body and a neck portion 8 are simultaneously extruded and covered.

The thickness t of the neck 8 is set to 0.1 in order to facilitate the work of separating the cable body 7 from the support wire 3.
0 mm or less. Although the lower limit of the thickness t of the neck portion is about 0.05 mm from the manufacturability of extrusion, it may be thinner as long as manufacture is possible. In addition, the best value of the thickness t of the neck portion in consideration of the easiness of the manufacturing and separating work is 0.05 m.
m to 0.07 mm. The notch 6a is provided for facilitating the operation of taking out the optical fiber 5 from the cable main body 7.

FIG. 1A shows an example of one optical fiber 5, but two optical fibers may be arranged side by side in parallel with each other. In the case of the self-supporting cable 9 'shown in FIG. 1 (B), a plurality of optical fibers 5 are laid or twisted around the strength member 4 having the coating, and the coating is performed so as to cover it. 6, a cable body 7 is provided, and the cable body 7 and the support wire 3 are connected by a neck 8 having a thickness of 0.10 mm or less.

The self-supporting cable shown in FIG.
Since the support wire portion 3 and the cable main body portion 7 are merely connected to each other by a thin neck portion 8 in a parallel state, if the wire is imaginarily extended through a wheel and the like, the wheel and the like can be used. As a result, the neck 8 is torn in places, causing the cable main body 7 to be partially separated from the support wire 3 and causing the cable main body 7 to hang partially. Therefore, when the self-supporting cable according to FIG. 1 is extended aerial, the following method is adopted.

FIG. 2 is a view for explaining a method of extending the self-supporting cable according to the present invention aerial.
2A is a conceptual diagram illustrating a state at the time of extension, and FIG. 2B is a perspective view illustrating a state of the self-supporting cable after the extension. 2, the same reference numerals as those in FIG. 1 denote the same components.
10 is a cable bundle, 11 is a utility pole, 12 is a gold car, 1
3 is a stand. A table 1 on which a cable bundle 10 on which a self-supporting type cable 9 has been wound is fixed with the axis of the bundle being vertical.
3 or put on the ground and pay out in the axial direction of the bundle,
The wire is extended by passing a wheel 12 suspended from a telephone pole 11.

Then, each time the cable bundle is unwound one turn, the cable is twisted once, so that the self-supporting cable 9 is fed out while being twisted around the traveling direction. Then, as shown in FIG. 2B, the self-supporting cable 9 after the extension is in a state where the support wire portion 3 and the cable main body portion 7 are twisted. Since the wire passes through the wheel 12 suspended from the telephone pole 11 during the extension, the cable is squeezed by the wheel 12 and has a small thickness connecting the support wire portion 3 and the cable body portion 7. The neck 8 is partially torn and has a separated portion. However, the support wire 3
And the cable main body 7 are twisted by the twisting at the time of extension, so that a state in which the support wire 3 and the cable main body 7 are separated from each other and the cable main body 7 partially hangs does not occur. Absent.

Further, since the self-supporting type cable has an extremely thin neck portion of 0.10 mm or less, even if the neck portion remains without being torn at the time of extension, the cable at the time of dropping the cable after the aerial extension is drawn. In the work of separating the support wire portion and the cable main body portion at the intermediate portion of the above, the support wire portion and the cable main body portion can be easily separated only by pulling them by hand.

In the method of laying out the cable bundle so that the shaft is vertical as shown in FIG. 2 and extending the cable bundle in the axial direction, the pitch of the twist is the length of one round of the bundle. The winding diameter of the cable bundle is 170mm or more, 950mm
It is desirable to make the following. Thereby, the twist pitch in the twisted state after the overhead wire drawing is 500 mm or more.
It can be 3000 mm.

After the cable is extended aerial, the support wire portion is retained on a utility pole. As a result, the overhead wire tension is borne by the support wire portion, but in this case, the cable body portion is spirally wound around the support wire portion by twisting, and the cable body portion is stretched and strained. Occurs. In order to prevent this elongation strain from becoming unacceptable, the twist pitch is preferably as large as possible, and more preferably 500 mm or more. However, if the twist pitch is too large, it is conceivable that when the neck is torn at the time of extending the wire and the support wire and the cable main body are separated, the cable main body partly hangs down. It is desirable that the distance be at most 3000 mm.

FIG. 2 shows an example of a method for drawing out a cable from a cable bundle in the axial direction. However, the method is not limited to the method shown in FIG. For example, if the cable is wound on a reel and the reel shaft is rotated around the advancing axis while the reel is being unwound from the reel, the cable is twisted according to the rotation of the reel shaft around the advancing axis. You can get out.

[0023]

EXAMPLE A self-supporting cable having the shape shown in FIG. 1A was manufactured by changing the thickness of the neck portion. A steel wire with an outer diameter of 1.2 mm is used for the supporting wire, and two outer diameters are 0.4 m for the tensile strength member.
As the optical fiber, a glass fiber coated with an element wire was used. Further, as a material for the covering of the supporting wire portion, a covering of the cable main body portion, and a material of the neck portion, a vinyl chloride resin D097C manufactured by Sumitomo Bakelite Co., Ltd. was used.

[0024]

[Table 1]

With respect to the self-supporting type cable manufactured by changing the thickness of the neck portion to six types, the separation strength of the neck portion, the separability of the neck portion, the manufacturability, and the overhead wire drawability were examined. The results are as shown in Table 1 above. In addition, the method of each test was as follows. 5 samples of 50 mm length from the cable
Each of the support wires and the cable body was gripped by a chuck of a tensile tester, and a tensile test was performed at a speed of 200 mm / min. ).

The workability of separation is "good" if the support wire and the cable main body can be separated by simply pulling them by hand in the middle of the cable. Those that could be separated by hand were rated "intermediate" and those that were difficult to separate by hand and required tools such as knives for separation were rated "poor". Manufacturability is 30
In a state where a 0-meter cable was just manufactured and wound on a reel, a part where the neck was torn and the support wire part was separated from the cable body part was found in one place. If the shape was not normally produced and the shape was manufactured normally, it was regarded as “good”.

In addition, for the aerial ductility, two self-supporting cables each having a length of 300 m are prepared, and one is pulled out from the reel without twisting the cable as in a normal drawing method, and suspended on a telephone pole. The wire was extended through the suspended wheel, and it was examined whether or not a place where the cable main body portion was separated from the support wire portion and hung was required. In addition, the other cable is extended while twisting the cable at a pitch of about 500 mm by the method shown in FIG. 2 (A), and is extended through a wheel train suspended from a telephone pole. It was examined whether or not a part that hangs apart can be seen. Then, when the support wire part and the cable main body part are separated and a hanging part of 100 mm or more is found in the cable main body part even at one place, "there is a hanging".
A sample in which a hanging portion of 100 mm or more was not recognized at all regardless of whether the support wire portion and the cable body portion were separated from each other was regarded as “good”.

According to these results, those of Examples 1 to 3 having a neck thickness of 0.05 mm to 0.10 mm have good separation workability, and the support wire portion and the cable main body at the intermediate portion. It is quite possible to perform the separation work from the parts manually. Also, regarding the aerial ductility in that case, there is a problem that the cable main body partly hangs down when there is no twist, but by having the twist, it is possible to prevent the cable main body from hanging down. I can do it. Further, at the time of manufacturing the cable, the support wire portion and the cable main body portion are not separated, so that a cable having a normal shape can be manufactured.

In the case of Comparative Example 1 where the neck thickness is 0.03 mm, the aerial ductility is sufficient for use if the wire is twisted and stretched in the same manner as in Examples 1 to 3, and the separation workability is good. It is easy to perform separation work after wire drawing, but at the end of cable production, the support wire part and the cable main body part are already separated, and the appearance when shipping as a self-supporting cable may be a problem. is there. Further, there is a possibility that the cable may be tangled when wound around the reel. In Comparative Examples 2 and 3, those having a neck thickness of 0.11 mm or more have no problem in terms of manufacturability and overhead wire drawability. There is a drawback in that the cable body cannot be separated only by hand, and a tool such as a knife is required.

From these results, it was found that the neck thickness was 0.10.
mm or less, and it is determined that it is preferable to extend the wire while giving a twist in the overhead wire drawing. Further, it is more preferable that the thickness of the neck is 0.05 mm to 0.07 mm, because the separation strength can be reduced.

[0031]

According to the self-supporting cable of the present invention, the cable main body and the support wire are parallel to each other and are connected to each other with a neck having a thickness of 0.10 mm or less along the longitudinal direction. The thickness of the neck portion is small, and the cable body can be separated from the support wire simply by pulling the support wire and the cable main body by hand at the middle of the cable.

[0032] Further, by extending the wire while twisting the cable around the traveling direction, the thin neck portion between the support wire portion and the cable main body portion is torn by ironing at the time of wire drawing. Even so, since the support wire portion and the cable main body portion are twisted by the twisting at the time of feeding, the cable main body portion does not hang down from the support wire portion.

[Brief description of the drawings]

FIGS. 1A and 1B are perspective views each showing an embodiment of a self-supporting cable of the present invention.

FIG. 2 is a view for explaining a method of extending a self-supporting cable according to the present invention imaginarily.

FIGS. 3A and 3B are cross-sectional views of a self-supporting cable according to the related art.

FIG. 4 is a sectional view of a self-supporting cable according to the prior art.

[Explanation of symbols]

 1, 21: support wire 2, 22: support wire portion coating 3, 23: support wire portion 4, 24: tensile strength member 5, 25: optical fiber 6, 26: cable body portion coating 6a, 26a: notch 7, 27: Cable body part 8, 28: Neck part 9, 9 ', 29, 29', 30: Self-supporting cable 10: Cable bundle 11: Electric pole 12: Gold wheel 13: Stand t: Thickness of neck part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02G 1/02 321 H01B 7/18 F

Claims (3)

[Claims] 1. A cable body containing an optical fiber and coated thereon and a support wire formed by coating the support wire are parallel to each other and have a thickness of 0.10 mm or less along a longitudinal direction. Self-supporting cable characterized by being connected by a neck. 2. A cable body containing an optical fiber and coated thereon and a support wire formed by coating the support wire are parallel to each other and have a thickness of 0.10 mm or less along the longitudinal direction. An imaginary extension method of a self-supporting cable, wherein the self-supporting cable connected by a neck is drawn out while being twisted around a traveling direction and imaginarily extended. 3. The twist pitch is 500 mm or more,
3. The method according to claim 2, wherein the cable is twisted so as to have a length of 3000 mm or less.