JPH103020A - Optical cable and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber capable of realizing a multicore structure while keeping the cable diameter small. SOLUTION: An optical fiber ribbon 10 is constituted by arranging plural coated optical fibers and covering them with a tape to form a coated fiber of ribbon and superposing plural layers of core wires to form a unit. Then, plural units of optical fiber ribbon 10 are put in a loose tube 16. Further, in order to identify the units, a binder 12 the color of which varies for each unit is wound around the optical fiber ribbon 10. Inside of the loose tube 16 is filled with a jelly 14 and a waterproof tape 18 and a steel tape 20 are wound arround the outer periphery of the loose tube 16. A cable jacket 23 in which a tension member 22 is buried covers an outside of the steel tape 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-core optical cable.

[0002]

2. Description of the Related Art Generally, an optical fiber ribbon 50 used for an optical cable is configured as shown in FIG. That is, first, a UV coating layer 5 made of an ultraviolet curable resin.
A plurality of optical fibers 50c covered with Ob are aligned, and the aligned plurality of optical fibers 50c are covered with a tape, whereby a tape core 50a is formed. The optical fiber ribbon 50 is formed by stacking the multi-core tape cores 50a in a plurality of stages. At present, the use of the optical fiber ribbon 50 configured as described above makes it possible to increase the density of optical cables, and further improves the work efficiency by collectively connecting terminals.

FIG. 1 shows an optical fiber ribbon 5 shown in FIG.
1 shows a configuration of a conventional optical cable in which one unit of 0 is mounted. One unit of the optical fiber ribbon 50 is housed in a tube 54, and the inside of the tube 54 containing the optical fiber ribbon 50 is filled with a compound 52 for waterproofing or the like. The outside of the tube 54 is covered with a cable sheath 62 in which a number of strength members 58 and 60 for preventing damage to the fiber are embedded.

In recent years, there has been an increasing demand for hundreds of optical fibers, but in the case of an optical cable having a tight structure as shown in FIG. Since the fiber is easily damaged during the bending of the optical cable, the number of cores is limited, and it is particularly difficult to mount the optical fiber ribbon 50 having 300 or more cores in the tube 54. Further, in one unit of the optical fiber ribbon 50, there is an improvement in that it is difficult to distinguish the multi-core optical fibers 50c arranged in the same manner.

FIG. 2 shows a configuration of an optical cable in which the number of optical fibers is increased while using the optical fiber ribbon 50. This optical cable has a central tensile member 6 provided at the center of the cable.
A plurality of tubes 64 are arranged around the inside of each of the tubes 8, in each of which tubes a fiber optic ribbon 50 is provided one by one, and a compound 6 is provided for waterproofing.
3 are filled. The outside of the multiple tubes 64 is covered with a plurality of nonconductive strength members 70 and further covered with a cable sheath 72. Around the tube 64,
The waterproofing compound 66 is filled.

[0006] The tube-assembled optical cable shown in FIG. 2 can have a considerably large number of fibers up to several hundreds. However, a large number of tubes 64 containing the optical fiber ribbons 50 are provided around the central tensile strength member 68. Since the cable must be mounted, the diameter of the cable becomes large, and the workability during construction and the facility cost are affected.

[0007]

SUMMARY OF THE INVENTION Focusing on the above prior art, the present invention provides an optical cable which has a high bending resistance of an optical fiber ribbon, excellent cable bending characteristics, and can easily increase the number of optical fiber cores. A manufacturing method is provided. Further, an optical cable capable of realizing a multi-core structure of several hundred fibers while keeping the cable diameter small, and a method of manufacturing the same are provided. Further, the present invention provides an optical cable capable of easily identifying an optical fiber mounted in the cable, and a method for manufacturing the same.

[0008]

For this purpose, the present invention provides a loose tube type optical cable having a plurality of optical fiber ribbons mounted in one loose tube. More specifically, a loose tube type in which a plurality of units of optical fiber ribbons each wound with a binder for identification are inserted into a loose tube and jelly is filled, and the loose tube is covered with a cable sheath containing a strength member. Optical cable. Alternatively, a loose tube in which a plurality of units of optical fiber ribbons each wound with a binder for identification are inserted into a loose tube and jelly is filled, and the outer periphery of the loose tube is covered with a tensile strength member and the cable sheath is covered. Optical fiber cable.

In this loose tube type optical cable, a waterproof tape and a metal tape are wound around the outer circumference of the loose tube, or a metal tape is wound around the outer circumference of the strength member. The waterproof tape can be made of a nonwoven fabric mixed with powder. The binder is preferably changed in color for each unit of the optical fiber ribbon so that it can be identified. The optical fiber ribbon is preferably twisted for each unit, or a plurality of units are bundled and twisted together. The loose tube shall be made of engineering plastic.

According to the present invention, as a method for manufacturing such a loose tube type optical cable, a plurality of optical fibers having a coating layer formed thereon are aligned to form a tape core, and the tape cores are stacked in a plurality of stages to form an optical fiber ribbon. A step of inserting a plurality of units of the optical fiber ribbon into a loose tube made of engineering plastic, filling the jelly, and a step of arranging a tensile strength member outside the loose tube and covering with a cable jacket. Provided is a method for manufacturing a loose tube type optical cable. When the optical fiber ribbon is inserted into the loose tube, the optical fiber ribbon is preferably twisted for each unit or a plurality of units are bundled and twisted together. Also,
It is preferable that different color binders be wound around each unit of the optical fiber ribbon.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 6 is a perspective view showing an optical fiber ribbon 10 housed in a loose tube in this example. The optical fiber ribbon 10 includes a plurality of optical fibers 10 covered with a coating layer 10b of an ultraviolet curable resin.
c in a line, and the aligned optical fiber 10c
Is covered with a tape to form a tape core 10a, and a plurality of these are laminated to form one unit. Since a plurality of units of the optical fiber ribbon 10 are put in one loose tube, a binder (binder) 12 of a different color is wound and tied for each unit for identification.

In the embodiment shown in FIG. 4, the optical fiber ribbon 10 shown in FIG. 6 has three units, a loose tube 1 made of engineering plastic having excellent wear resistance and corrosion resistance.
6 is inserted. The inside of the loose tube 16 on which the optical fiber ribbon 10 is mounted is filled with a jelly compound 14 which is excellent in waterproofness and corrosion resistance and hardly reacts chemically. Further, a waterproof tape 18 made by mixing powder that absorbs water and expands with a nonwoven fabric of polyester is wound around the outer circumference of the loose tube 16, and the outside of the waterproof tape 18 is provided with external mechanical and mechanical components. It is covered with a steel tape 20 to protect the loose tube 16 from environmental influences. The steel tape 20 is wound in a direction perpendicular to the cable core. This steel tape 2
The outside of 0 is covered with a cable outer sheath 23 made of polyethylene in which a strength member 22 is embedded.

The method of manufacturing an optical cable in which a plurality of units of the optical fiber ribbon 10 are put in one loose tube 16 as described above is preferred as follows.

[0015] UV curable resin coating layer 10b
The optical fiber 10c provided with
2 or more cores of 12 cores are aligned, and UV curable resin U
Tape coated with V coating and tape core 10a
To form Then, the optical fiber ribbon 10 is formed by stacking the multi-core tape cores 10a in a plurality of stages. Then
In order to distinguish the multi-layered optical fiber ribbons 10, the units are bound by binders 12 of different colors one by one. The binder 12 may be a bind-tape or a bind-yarn.

In order to increase the strength, the optical fiber ribbon 10 manufactured as described above is twisted one unit at a time, or bundled and twisted together with three units shown in FIG. Insert into tube 16. At this time, loose tube 1
The jelly 14 is also filled in the inside 6.

After the optical fiber ribbon 10 is placed in the loose tube 16, the outer periphery of the loose tube 16 is covered with a waterproof tape 18 and a steel tape 20 is wound thereon. Then, the tensile strength member 22 is embedded and the cable
By coating 3, the loose tube type optical cable is completed.

FIG. 5 shows another embodiment of the loose tube optical cable. In this optical cable, three units of the optical fiber ribbon 10 of FIG. 6 are put in a loose tube 24 made of engineering plastic having excellent wear resistance and corrosion resistance, and filled with a jelly 14 excellent in non-conductivity and non-hygroscopicity. It is. Each optical fiber ribbon 1
Numerals 0 are bound by binders 12 of different colors for identification.

On the outer peripheral surface of the loose tube 24, a number of tensile strength yarns 30, which are tensile strength members for protection from mechanical and environmental influences, are uniformly arranged. Further, a steel tape 28 for protecting the loose tube 24 from mechanical and environmental influences is wound around the tensile strength yarn 30 in a direction perpendicular to the cable core. Then, from above, it is covered with a polyethylene sheath 23 made of polyethylene for protection.

The method of manufacturing an optical cable in which a plurality of units of the optical fiber ribbon 10 are put in one loose tube 24 as described above is as follows.

The optical fiber ribbon 10 produced in the same manner as described above and tied up with the binder 12 is loosened while being filled with the jerry 14 while being twisted one unit at a time or by twisting together the three units shown. Insert into tube 24. Next, a number of tensile strength yarns 30 are uniformly arranged on the outer peripheral surface of the loose tube 24, and the high strength yarns 30 are covered with a steel tape 28 and then covered with a cable jacket 23, thereby producing a loose tube type optical cable.

[0022]

According to the loose tube type optical cable using the optical fiber ribbon of the present invention, by mounting a plurality of units of optical fiber ribbons in one loose tube, the mounting efficiency of the fiber is increased and the cable diameter is reduced. It is possible to increase the number of cores while suppressing it.
It is also suitable for a multi-core structure with zero or more cores. In addition, since the optical fiber ribbon is divided into a plurality of units and has a loose structure in which the optical fiber ribbon is inserted into one loose tube, bending loss of the optical fiber ribbon can be minimized, and the bending characteristics of the optical cable can be improved. Furthermore, by inserting a plurality of optical fiber ribbons bound by different color binders, the optical fiber ribbon can be easily identified from the color of the binder, and in addition, all of the optical fiber ribbons can be stored in one loose tube. The fiber connection work is easy.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a conventional structure of an optical cable using an optical fiber ribbon.

FIG. 2 is a cross-sectional view showing another conventional structure of an optical cable using an optical fiber ribbon.

FIG. 3 is a cross-sectional view showing a configuration of a conventional optical fiber ribbon.

FIG. 4 is a sectional view showing an embodiment of a loose tube type optical cable using an optical fiber ribbon according to the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of a loose tube type optical cable using an optical fiber ribbon according to the present invention.

FIG. 6 is a partial cross-sectional perspective view showing the structure of the optical fiber ribbon according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical fiber ribbon 10a Tape core wire 10b Coating layer 10c Optical fiber 12 Binder 14 Jerry 16, 24 Loose tube 18 Waterproof tape 20, 28 Steel tape (metal tape) 22 Strength member 23 Cable sheath 30 Strength yarn (tensile material)

Claims (18)

[Claims] 1. A loose tube type optical cable in which a plurality of units of optical fiber ribbons each wound with a binder for identification are inserted into a loose tube and jelly is filled, and the loose tube is covered with a cable sheath containing a strength member. . 2. A loose tube type optical cable according to claim 1, wherein a waterproof tape and a metal tape are wound around the outer circumference of the loose tube. 3. The loose tube type optical cable according to claim 2, wherein the waterproof tape is made of a nonwoven fabric mixed with powder. 4. The loose tube optical cable according to claim 1, wherein the color of the binder is changed for each unit of the optical fiber ribbon. 5. The loose tube type optical cable according to claim 1, wherein the optical fiber ribbon is twisted for each unit. 6. The loose-tube optical cable according to claim 1, wherein the optical fiber ribbon comprises a plurality of units bundled and twisted together. 7. The loose tube optical cable according to claim 1, wherein the loose tube is made of engineering plastic. 8. Inserting a plurality of optical fiber ribbons each wound with a binder for identification into a loose tube and filling the loose tube with jelly, covering the outer periphery of the loose tube with a tensile strength member, and covering a cable sheath. A loose tube type optical cable. 9. The loose tube optical cable according to claim 8, wherein a metal tape is wound around the outer periphery of the tensile strength member. 10. The loose tube type optical cable according to claim 8, wherein the color of the binder is changed for each unit of the optical fiber ribbon. 11. The loose tube type optical cable according to claim 8, wherein the optical fiber ribbon is twisted for each unit. 12. The optical fiber ribbon according to claim 8, wherein a plurality of units are bundled and twisted together.
Loose tube type optical cable according to the item. 13. The loose tube type optical cable according to claim 8, wherein the loose tube is made of engineering plastic. 14. A process of arranging a plurality of optical fibers having a coating layer formed thereon to form a tape core, stacking the tape cores in a plurality of stages to form an optical fiber ribbon, and placing the optical fiber in a loose tube made of engineering plastic. A method of manufacturing a loose tube type optical cable, comprising: inserting a plurality of fiber ribbons and filling the jelly; and arranging a strength member outside the loose tube and covering with a cable jacket. 15. The manufacture of a loose tube optical cable according to claim 14, wherein when inserting the optical fiber ribbon into the loose tube, the optical fiber ribbon is twisted for each unit or a plurality of units are bundled and twisted together. Method. 16. The method of manufacturing a loose tube type optical cable according to claim 14, wherein a binder of a different color is wound around each unit of the optical fiber ribbon. 17. An optical cable using an optical fiber ribbon, wherein a plurality of optical fiber ribbons are put in one loose tube. 18. The optical cable according to claim 17, wherein the optical fiber ribbons are bound with binders of different colors.