JPH08286084A - Optical cable for optical fiber combined overhead earth-wire - Google Patents

Abstract

PURPOSE: To provide an optical cable for an optical fiber combined overhead earth-wire with which an improvement in durability, etc., are attained and the taking out of optical fibers is facilitated. CONSTITUTION: This optical cable 1 for the optical fiber combined overhead earth-wire has the optical fibers 2, 3 meandering along a longitudinal direction and a coating member 5 for bundling and coating these optical fibers 2, 3 together with a tension member 4. The optical cable 1 for the optical fiber combined overhead earth-wire has otherwise the coating member 5 for bundling and coating the plural optical fibers 2, 3 and a filamentary member 4 which is disposed on the outer periphery of the optical fibers 2, 3 and tears the coating member 5 when this filamentary member is pulled outward in a radial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cable used for an optical fiber composite overhead wire.

[0002]

2. Description of the Related Art FIG. 3 shows an optical fiber composite overhead ground wire (OPGW).
It is sectional drawing which shows an example. As shown in the figure, the optical fiber composite overhead ground wire a includes a metal tube c made of aluminum or the like for accommodating an optical cable b therein, and a metal element wire d such as an aluminum-covered steel wire twisted around the outer periphery of the metal tube c. Have and.

As shown in FIG. 4, a spacer e with a groove made of aluminum, resin or plastic is inserted in the metal tube c, and an optical cable b is accommodated in the groove f with a relatively large margin. The optical cable b has a structure in which a tension member g made of FRP or the like arranged in the central portion and an optical fiber h twisted around the outer peripheral portion thereof are wound together with a tape i.

An optical fiber composite overhead ground wire a as shown in FIG. 5 is also known, in which a metal tube c is not provided and a metal element wire d is directly twisted around the outer peripheral portion of a spacer e. There is. Therefore, the optical cable b is accommodated in the space between the groove f and the metal wire d.

The optical fiber composite overhead ground wire a as described above is generally known as a spacer type.

[0006]

By the way, the optical fiber composite overhead ground wire a is installed on the uppermost part of the steel tower and is exposed to a severe natural environment such as strong wind and vibration. And optical cable b
Are often subjected to mechanical stress such as elongation and lateral pressure (crush load), which causes the life of the optical fiber h to be shortened. Therefore, in the above-mentioned one, the optical fiber h is protected by the metal tube c, the spacer e, the tension member g, etc., but the appearance of an optical cable with further improved durability and a longer life is desired. ing.

On the other hand, there is a case where the optical cables b are connected to each other on, for example, a steel tower. At this time, it is necessary to take out the internal optical fiber h. The workability was poor. Further, when the optical fiber h is covered with a cushioning material for preventing external damage, the work of removing the cushioning material is also troublesome.

Therefore, the present invention was devised to solve the above-mentioned problems, and an object thereof is to improve durability and the like, and to make it easy to take out an optical fiber. To provide.

[0009]

To achieve the above object, an optical fiber composite overhead ground wire optical cable according to claim 1 of the present invention comprises an optical fiber meandering along the longitudinal direction and the optical fiber. And a covering member that is bundled together with the tension member to cover the same.

According to a second aspect of the present invention, there is provided an optical fiber composite overhead ground wire optical cable in which a plurality of optical fibers are bundled and coated, and a coating provided on the outer periphery of the optical fiber and radially outward. It is provided with a linear member that cuts the cover by being pulled.

The present invention according to claim 3 provides the invention according to claim 2.
In the optical fiber composite overhead ground wire optical cable described,
The optical fiber meanders along the longitudinal direction.

The present invention according to claim 4 provides the invention according to claim 2.
Alternatively, in the optical fiber composite overhead ground wire optical cable described in any one of 3 above, the filament member is a tension member.

[0013]

According to the first aspect of the present invention, since the optical fiber is meandered, it is possible to absorb elongation force, lateral pressure, etc. applied to the optical fiber by the deformation of the optical fiber itself.

According to the second aspect of the present invention, the coating can be cut by pulling the filament member outward in the radial direction.

According to the present invention of claim 3, claim 1
Similar to the one described, it is possible to absorb elongation force and the like by the optical fiber itself.

According to the fourth aspect of the present invention, the tension member is also used as the linear member.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an optical cable according to the present invention. As shown in the figure, an optical fiber composite overhead ground wire optical cable 1 has one optical fiber 2 located at the center thereof, and five optical fibers 3 and a tension of the same diameter on the outer peripheral side thereof. The member 4 and the member 4 are arranged in an annular shape. The optical fibers 2 and 3 and the tension member 4 are embedded together in the covering body 5 in a state of meandering along the longitudinal direction. Particularly, in the conventional case, the optical fiber is twisted around the tension member on the outer peripheral side, but in the present embodiment, the tension member 4 is arranged on the outer peripheral side, and the tension member 4 and the optical fiber 3 are not twisted but meander. It is only parallel in the state. The optical fibers 2 and 3 and the tension member 4 are in an arbitrary meandering state, and the covering 5 is also inserted into the gap between them. The cover 5 has at least a predetermined thickness t on the outer peripheral side of the optical fiber 3 or the tension member 4.

As a method of manufacturing the optical cable 1, the optical fibers 2 and 3 and the tension member 4 are arranged in parallel and bundled together, and these are melted in an ultraviolet curable resin (UV resin) as a base material of the covering 5. Embed in the state. Then, the optical fibers 2 and 3 and the tension member 4 are subjected to vibration or the like to create a meandering state thereof, and the ultraviolet curable resin in the molten state is rapidly cooled and cured. By such a jacketing process, the optical fibers 2 and 3 and the tension member 4 are embedded in the covering body 5 in a meandering state. By continuously performing this, mass production of the optical cable 1 can be easily performed.

Next, the operation of this embodiment will be described.

First, when the optical cable 1 is connected, the tension member 4 is arranged on the outer peripheral side. Therefore, by pulling the tension member 4 outward in the radial direction, the tension member 4 functions as a tension string and the covering 5 is formed. Can be cut into pieces. Therefore, the optical fibers 2 and 3 can be taken out from this portion, and the taking out of the optical fibers 2 and 3 can be facilitated. From this, the tension member 4 also serves as a linear member for cutting the cover 5. However, this can be a separate member, but by using it as a separate member, the number of parts, cost, etc. can be reduced.

On the other hand, in the optical cable 1 inserted into the optical fiber composite overhead ground wire, when elongation or tensile force is applied, the force is generated by the optical fibers 2 and 3 and the tension member 4 extending from the meandering state. Absorbs.
Even when the optical fibers 2 and 3 are completely stretched, the tension member 4, which is a tensile strength member, finally resists the force, so that the optical fibers 2 and 3 are prevented from being stretched or damaged. When a lateral pressure or a crush load is applied, the cover 5 and the optical fibers 2 and 3 are deformed and absorb the deformation, whereby the entire optical cable 1 can have a stress relaxation effect, and the durability of the optical cable 1 is improved. It is possible to improve and prolong the service life.

For this reason, for example, the tension member 4 can be made of resin such as FRP as in the conventional case, but it is more effective to use a dummy fiber having rigidity characteristics equivalent to those of the optical fibers 2 and 3. That is, by doing this, the optical fibers 2 and 3 and the tension member 4 are
They can be arranged evenly while adding extra length due to meandering.

Since the base material of the cover 5 is made of an ultraviolet curable resin, it can be easily manufactured by the above-mentioned manufacturing method. The cover 5 can be made relatively flexible to enhance the stress relaxation effect. There are various advantages such that the covering body 5 is easily torn and the workability is improved. Note that as the base material of the covering body 5, other materials can be selected as long as they produce such advantages.

In particular, in the above manufacturing method, the arrangement or bundling of the optical fibers 2, 3 and the tension members 4 and the coating of the coating 5 are performed in one step, so that the twisting and the tape winding can be performed as in the conventional case. Therefore, the manufacturing process can be facilitated and the manufacturing cost can be reduced without performing the separate process. Further, vibrating the optical fibers 2, 3 and the tension member 4 to make them meander is also one of the features of the present manufacturing method.

Next, a modified embodiment will be described. As shown in FIG. 2, in this modified example, the tension member 4 has a larger diameter than the optical fibers 2 and 3, and the thickness t ₁ of the cover 5 located radially outside the tension member 4 is almost zero. The value is close to. That is, the radial distance occupied by the tension member 4 by its outer diameter and the meandering is
It is equal to or less than the distance from the central optical fiber 2 to the outer peripheral surface of the cover 5. by this,
Even if the thickness t ₂ of the coating 5 on the outer peripheral side of the optical fiber 3 is relatively large, the thickness t ₁ on the outer peripheral side of the tension member 4 is almost zero. While it is easy to perform, the optical fibers 2 and 3 can be sufficiently protected.

The following method can be considered for the meandering of the optical fibers 2, 3 and the like. That is, the optical fibers 2 and 3
The tension member 4 and the tension member 4 are arranged in a straight line without being meandered, and the cover 5 is covered on these to form the optical cable 1. When the optical fiber composite overhead wire is inserted, the spacer is inserted while tension is applied. If the tension is loosened after the insertion, the optical cable 1 can be made to meander by contracting the spacer. The extra length can absorb the elongation and prevent damage. An advantage of this method is that the optical cable 1 is easily manufactured because the optical fibers 2 and 3 are not vibrated.

Then, assuming that the optical fiber 2,
If 3 has a sufficient strength, such a structure that does not meander may be used.

Such an optical cable can be applied not only to the optical fiber composite overhead ground wire shown in FIGS. 3 and 5, but also to various types of optical fiber composite overhead ground wires.

[0030]

The present invention exhibits the following excellent effects.

(1) According to the first aspect of the present invention, it is possible to improve the durability and prolong the service life.

(2) According to the present invention described in claim 2, it is possible to easily take out the optical fiber.

(3) According to the present invention as defined in claim 3, it is possible to easily take out the optical fiber and improve the durability.

(4) According to the present invention described in claim 4, the number of parts, the cost, etc. can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an optical cable according to the present invention.

FIG. 2 is a perspective view showing a modified example.

FIG. 3 is a cross-sectional view showing an optical fiber composite overhead ground wire.

FIG. 4 is a cross-sectional view showing a conventional optical cable.

FIG. 5 is a cross-sectional view showing an optical fiber composite overhead ground wire.

[Explanation of symbols]

 1 Optical cable 2, 3 Optical fiber 4 Tension member (line member) 5 Cover

Claims (4)

[Claims] 1. An optical fiber composite overhead ground wire optical cable comprising: an optical fiber meandering along a longitudinal direction; and a cover body that bundles the optical fiber together with a tension member to cover the optical fiber. 2. A coating body for bundling and coating a plurality of optical fibers, and a linear member provided on the outer periphery of the optical fibers and splitting the coating body by being pulled radially outward. Optical fiber composite optical cable for overhead ground wire. 3. The optical fiber composite overhead ground wire optical cable according to claim 2, wherein the optical fiber meanders along the longitudinal direction. 4. The optical fiber composite overhead ground wire optical cable according to claim 2, wherein the linear member is a tension member.