JPH11297134A - Optical fiber combined overhead cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict increase of wind pressure load and increase of tension due to snow coverage. SOLUTION: In a cable 21, an optical fiber 14 is incorporated in an insulating coating on the outer periphery of a conductor 12 or in a fin 23a provided on the insulating coating 23. As an outside dimension is less increased following the combination of the optical fiber 14, the increase of wind pressure load is restricted. The fin 23a prevents snow coverage and avoids the increase of tension due to snow coverage. In a structure that a pipe for inserting the optical fiber therethrough is incorporated in the insulating coating, no optical fiber is originally placed but the insertion of the optical fiber through the pipe is simply made when an optical fiber is required later, and so no replacement of the wire itself is required as usual, resulting in advantage in profitability and waste of resources to be avoided. As a portion of the fin 23a is cut off by a knife and separated from the outer periphery of the conductor, no cut of the optical fiber 14 is required if the conductor is cut at a turning portion of the anchor end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical fiber composite overhead electric wire in which an optical fiber and an overhead electric wire are combined.

[0002]

2. Description of the Related Art In general, when an optical fiber cable is wired, as shown in FIG. 6, a self-supporting type optical fiber cable 3 is formed by integrally molding an optical fiber cable 1 and a suspension line 2 having strength with a synthetic resin 4. Is used. In this case, the synthetic resin 4 is usually molded into a structure in which the outer peripheral portion 4a of the optical fiber cable and the outer peripheral portion 4b of the suspension line are integrally joined by a thin portion 4c. Although not shown in detail, the optical fiber cable 1 has, for example, a structure in which optical fibers are housed in a plurality of optical fiber housing grooves formed on the outer peripheral surface of the spacer. When laying an optical fiber cable, it is often necessary to lay a distribution line on the line or to lay the distribution line at the same time. Since it is complicated to provide separately, an electric wire (insulated wire) is often used as the suspension wire 2.

[0003]

The conventional self-supporting optical fiber cable 3 has a molded part (synthetic resin 4).
This is bulky (the dimension a in FIG. 6 is large), so that there is a problem that the influence of the wind pressure load is large. Further, since the structure does not prevent snow accumulation, there is a problem that the tension increases due to snow accumulation on the mold portion.

In the case of a self-supporting type optical fiber cable 3 using an electric wire as the suspension line 2, when an optical fiber cable is laid on an existing electric wire path later, the existing electric wire itself must be re-stretched. Therefore, there is a problem that it is uneconomical and wastes resources.

An object of the present invention is to provide an optical fiber composite overhead electric wire which is less liable to be affected by wind pressure load and is less likely to cause an increase in tension due to snow accumulation. In addition, the present invention provides an optical fiber composite overhead electric wire that is economical and avoids wasting resources when an optical fiber is laid in an existing distribution line mainly without the need to re-stretch the existing electric wire. The purpose is to:

[0006]

An optical fiber composite overhead electric wire according to the present invention, which solves the above-mentioned problems, is characterized in that an optical fiber is incorporated inside an insulating coating on the outer periphery of a conductor.

According to a second aspect of the present invention, there is provided the optical fiber composite overhead electric wire according to the first aspect, wherein the optical fiber is built in a ridge in a conductor longitudinal direction formed on an outer periphery of the insulating coating.

According to a third aspect of the present invention, in the optical fiber composite overhead electric wire according to the first or second aspect, a tube for inserting an optical fiber is built in the insulating coating.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to the embodiment shown in FIGS. FIG. 1 is a perspective view of an optical fiber composite overhead electric wire 11 according to a first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of FIG. The optical fiber composite overhead electric wire 11 is provided with an insulating coating 13 on the outer periphery of a conductor 12 at the center, and incorporates, for example, an optical fiber (optical fiber core) 14 in the insulating coating 13. The material of the insulating coating 13 is a normal electric insulating material such as polyethylene or vinyl chloride. For example, the thickness c of the optical fiber 14 built-in portion is about 3 to 4 mm for the normal coating portion thickness b = 2 mm. do it. This insulating coating 1
3 can be coated by extrusion molding of a resin.

According to this optical fiber composite overhead electric wire 11, the degree of bulking is not so large as the optical fiber 14 is composited, so that an increase in wind pressure load can be suppressed. In addition, compared with the conventional optical fiber composite overhead electric wire (in FIG. 6, the case where the suspension line 2 is an electric wire), there is less snow accumulation,
An increase in load due to snow accretion can also be suppressed.

FIG. 3 is a perspective view of an optical fiber composite overhead electric wire 21 according to a second embodiment of the present invention, and FIG. 4 is an enlarged transverse sectional view of FIG. This optical fiber composite overhead electric wire 21 utilizes the structure of a so-called hard-to-snow electric wire, and is provided inside a fin (protrusion) 23a in the longitudinal direction of the electric wire formed on the outer periphery of the insulating coating 23 to prevent snow accumulation. The optical fiber 14 is built in. In this case, it is an optical fiber composite overhead electric wire 21 in which one optical fiber 14 is composited. 12 is a conductor.

According to the optical fiber composite overhead electric wire 21, the operation is the same as that of a normal hard-to-snow electric wire, but the snow accumulated on the optical fiber composite overhead electric wire 21 further grows in the circumferential direction. When the growing snow is fin 23
a, and falls due to a shearing force. Therefore, an increase in load due to snow accretion can be suppressed. In addition, the degree of bulking due to the combination of the optical fibers 14 is small, and an increase in wind pressure load can be suppressed.

The root of the fin 23a of the insulating coating 23 (portion (a) in FIG. 4) is cut with a knife, and the fin 23a is cut.
Since the portion "a" can be easily separated from the conductor outer peripheral portion 23b of the insulating coating 23, the optical fiber 14 is not cut without cutting the conductor 12 even when it is necessary to cut the conductor 12 at, for example, a termination edge portion (jumper portion). Leave conductor 12
Can be framed. When the optical fiber 14 needs to be branched, the fin 23a can be cut off from the conductor outer peripheral portion 23b, and only the optical fiber 14 can be branched. Further, both the conductor 12 and the optical fiber 14 can be cut and connected independently.

FIG. 5 shows a third embodiment of the present invention. In the optical fiber composite overhead electric wire 21 shown in FIGS. 3 and 4, the optical fiber 14 is directly incorporated in the fin 23 a of the insulating coating 23, whereas the optical fiber composite overhead electric wire 31 of this embodiment is A tube 34 for inserting an optical fiber instead of a fiber is built in.

The above-mentioned optical fiber composite overhead electric wire 31 is suitable for a case where it is not necessary to lay an optical fiber when laying the electric wire. When it is necessary to lay an optical fiber after laying the optical fiber composite overhead electric wire 31, the laying of the optical fiber can be performed by inserting the optical fiber into the tube 34.
Therefore, unlike the related art, it is not necessary to rewire the electric wire itself, which is economical and can avoid wasteful use of resources.

[0016]

According to the present invention, since the optical fiber is built in the insulating coating on the outer periphery of the conductor, the degree of bulking is small with the compounding of the optical fiber, and the wind pressure load increases. Can be suppressed.

According to a second aspect of the present invention, when the optical fiber is incorporated in a fin formed on the outer periphery of the insulating coating, a snow-preventing action by the ridge can be obtained.
An increase in load due to snow accumulation can be suppressed. In addition, the ridge portion incorporating the optical fiber can be easily separated from the outer peripheral portion of the conductor by a knife, so that, for example, at the termination edge wrapping portion (jumper portion), the conductor is wrapped without cutting the optical fiber. It is also possible to branch only the optical fiber. Further, both the conductor and the optical fiber can be cut and connected independently.

According to a third aspect of the present invention, when a tube for inserting an optical fiber is built in the insulating coating, the optical fiber is not laid at the time of the initial laying of the electric wire, but it is necessary to lay the optical fiber later. At this time, the optical fiber can be inserted through the tube, so that it is not necessary to rewire the electric wire itself as in the related art, which is economical and can avoid wasteful waste of resources.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical fiber composite overhead electric wire according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of FIG.

FIG. 3 is a perspective view of an optical fiber composite overhead electric wire according to a second embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of FIG.

FIG. 5 is a perspective view of an optical fiber composite overhead electric wire according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a conventional optical fiber composite overhead electric wire.

[Explanation of symbols]

 11, 21, 31 Optical fiber composite overhead electric wire 12 Conductor 13, 23 Insulation coating 14 Optical fiber 23a Fin (protrusion) 23b Conductor outer peripheral portion 34 Tube

Claims (3)

[Claims] 1. An optical fiber composite overhead electric wire, wherein an optical fiber is built in an insulating coating on the outer periphery of a conductor. 2. The optical fiber composite overhead electric wire according to claim 1, wherein said optical fiber is incorporated in a ridge in a conductor longitudinal direction formed on an outer periphery of said insulating coating. 3. An optical fiber insertion tube is built in the insulating coating.
An optical fiber composite overhead electric wire as described in the above.