JPH02282710A - Multifiber optical cable and production thereof - Google Patents

Abstract

PURPOSE:To produce the above cable with one time of production process by adopting the structure consisting in disposing molded pipes consisting of plastic tapes housing optical fibers around a central high-tensile body and integrally coating the central tensile body and the molded pipes. CONSTITUTION:This optical cable is constituted by having the structure consisting in disposing plural pieces, for example, 6 pieces of the molded pipes 2, which are molded of plastic tapes of >=0.1mm thickness and <=0.3mm thickness housing tearing cords 4 and plural pieces of the optical fibers 3, around the high-tensile body 1 and applying the integral coating 5 thereon. For example, a steel wire or FRP or the like is used as the high-tensile body 1. The plastic tapes of >=0.1mm thickness and <=0.3mm thickness which can be easily pulled and torn by the tearing cords 4, are provided with the adequate cushion effect to external force and are formed to the pipe shape adequate for the number of the optical fibers 3 are applied as the molded pipes 2. The production with one stage of aggregating and integral coating is executed in this way and the production of the multifiber optical cables with a slight equipment investment and equipment floor area is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-core optical cable used for optical communications, and particularly relates to its structure and manufacturing method.

[Conventional technology]

Conventionally, multi-core cables with a structure using this type of pipe were
A multi-core cable with a structure using loose tubes is used.

In addition, the conventional method for manufacturing this type of multi-core cable is as follows:
This process is performed in at least two steps: a multi-core cable assembly process and an outer sheathing process.

Note that when manufacturing multi-core optical cables, a large-sized assembly machine equipped with an optical fiber supply device corresponding to the number of optical fibers is used in the assembly process.

[Problem to be solved by the invention]

Conventional multi-core optical cables of this type require twisting when arranging the optical fibers, especially in the manufacturing method thereof, and are provided with an assembly step for imparting the twist and maintaining the twisted state.

In addition, when assembling multi-core optical cables, it is necessary to have an optical fiber supply that is suitable for the fiber characteristics, and problems such as the large installation area of the assembling machine and large capital investment due to the increase in the size of the equipment arise. be.

Furthermore, the outer diameter of conventional optical cables is determined for each stage, and the outer diameter does not necessarily correspond to the required number of fibers.

Furthermore, since the manufacturing process of conventional multi-core optical cables of this type requires two steps, an assembling process and a coating process, it takes time to produce and is also relatively expensive. Inevitable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a method for manufacturing this type of multi-core optical cable and a multi-core optical cable that can be manufactured in -1 manufacturing steps.

[Means to solve the problem]

In order to achieve the above object, the multi-core optical cable of the present invention includes a plurality of plastic tapes having a thickness of Q,l mm or more and a thickness of 0°3 mm or less, which house optical fibers around a central tensile strength member. It is characterized by having a structure in which a molded pipe consisting of the above is arranged, and the central tensile strength member and the molded pipe are collectively covered.

Moreover, it is effective to have a structure in which the molded pipe accommodates the tearing string together with the optical fiber.

Furthermore, a structure in which the formed pipe containing the optical fiber and the tear string is provided with periodically reversed twists alternately left and right in the longitudinal direction of the optical cable, and is coated with a bundle is effective.

In the method for manufacturing a multi-core optical cable of the present invention, an optical fiber, a tear string, a plastic tape with a thickness of 0.1 mm or more and a thickness of 0.3 mm or less, and a tensile strength body are arranged on a supply stand, and the tensile strength is A molding die is placed around the body to form the plastic tape into a pipe shape while storing the optical fiber and the tear string. The pipe is passed through a plastic molding machine with the pipe placed around the central tensile strength member, and the molded pipe containing the optical fiber and the tear string is placed around the tensile strength member and coated all at once by the plastic molding machine. The feature is that multi-core optical cables made of molded pipes are assembled and coated all in one process.

Furthermore, it is effective by including the step of giving twist to the molded pipe by periodically inverting the molded pipe formed from a plastic tape containing the optical fiber and the tear string in the longitudinal direction of the optical cable alternately left and right.

[For production]

The multi-core optical cable of the present invention has a thickness of 0.1 mm or more and a thickness of 0.1 mm or more.
A structure is created in which a plastic tape with a thickness of 3 mm or less is molded into a pipe shape, and a plurality of molded pipes containing desired optical fibers and tear strings are arranged around the outer periphery of a tensile strength member, and a -bracket coating is applied. Because of its structure, the optical fiber can be easily taken out by tearing the plastic pipe with a tear string, and the separate molded pipes are individually protected by a bulk coating, so they have excellent post-branching properties. , it is easy to make withdrawals for each user.

Furthermore, since the molded pipe that accommodates the optical fibers forms a certain amount of voids within the multi-core optical cable, it provides a cushioning effect against external forces and ensures mechanical strength.

Furthermore, by appropriately selecting the diameter of the molded pipe that houses the optical fiber and tear string, it is possible to provide enough buoyancy to prevent sinking when installing optical cables in channels such as canals, making it possible to apply the pouring method and making it economical. This enables a new installation method.

The method for manufacturing a multi-core optical cable of the present invention is a method of manufacturing the conventional multi-core optical fiber assembly process and coating process in one process, thereby reducing equipment investment and equipment area. This reduces manufacturing time, reduces manpower, and makes it possible to manufacture inexpensive multi-core optical cables.

The outer diameter of the optical cable also depends on the number of optical fibers to be accommodated, as well as the outer diameter of the molded pipe made of plastic tape with a thickness of 0.1 mm or more and 0.3 mm or less, and the number of molded pipes to be covered. Because it can be changed freely,
A desired optimal thin-diameter multi-core optical cable can be manufactured.

In addition, the molded pipe made of plastic tape with a thickness of 0.1 mm or more and 0.3 mm or less is used to prevent adhesion of optical fibers when collectively covering with a central tensile strength member, prevent the effects of heat, and facilitate the removal of optical fibers. It has an effect. Examples will be described below based on the drawings.

〔Example〕

FIG. 1 is a diagram showing a cross-sectional structure of an embodiment of a multi-core optical cable of the present invention. A plurality of molded pipes 2 made of plastic tape with a thickness of 0.1 mm or more and a thickness of 0.3 mm or less are arranged around the tensile strength member 1, each containing a tear string 4 and a desired number of optical fibers 3, in this embodiment, six. It is constructed with a structure in which this arrangement is made and a bracket covering 5 is applied.

As the tensile strength member 1, for example, steel wire, FRP, or the like is used. The formed pipe 2 has a thickness of 0.1 mm or more, can be easily torn with a tearing string 4 made of Kevlar Q rope, etc., has an appropriate cushioning effect against external forces, and is suitable for the optical fiber 3 to be stored. Therefore, a plastic tape with a thickness of 1 mm or more and 0.3 mm or less is used because it can be easily processed into a pipe shape.

In this embodiment, the optical fiber 3 is a single optical fiber, but the multi-core optical cable configuration example of the present invention also includes the use of one or more optical fiber units, optical fiber tape cores, etc. .

Further, it is also an aspect of the present invention that a communication line is housed in the formed pipe 2.

The collective coating 5 is made of, for example, polyethylene, ABS, vinyl, polyamide (nylon), etc., and is coated to a predetermined outer diameter. In addition, in order to enhance the protection function against external forces, a hard material is preferable, and it is preferable to use high-density polyethylene, ABS, semi-rigid vinyl, or the like.

FIG. 2 shows an outline of the manufacturing method steps for the multi-core optical cable of the present invention having the structure illustrated in FIG. 1. On the supply side of the plastic molding machine 27, the tensile strength body 21, the plastic tape 221, the optical fiber 23, and the tearing string 24 are arranged in the respective supply stands 20 in required numbers.

A desired number of molding dies 26 for forming the plastic tape 221 into a pipe shape while accommodating the optical fiber 23 and tearing string 24 are arranged around the tensile strength body 21 and around the tensile strength body 21 .

Centering around the tensile strength body 21, the plastic tape 221 is passed through the tensile strength body 21 and the heated molding die 26, and the molded pipe 22, which is formed into a pipe shape while housing the optical fiber 23 and tearing string 24, is passed through the plastic molding machine 27. A plastic molding machine 27 applies a bulk coating 25 to the tensile strength member 21 with the molded pipe 22 arranged around it, thereby producing a multi-core optical cable 200.

Note that even if the molding die 26 is not heated, the plastic tape 221 can be sufficiently formed into a pipe using only the heat of the plastic molding machine 27 and the temperature of the resin covering the tube.

In addition, in consideration of the effects of elongation strain on optical fibers and the flexibility of optical cables, it is possible to easily create molded pipes containing optical fibers and drawn strings by including a twisting process in a plastic molding machine, for example. , it is possible to apply the one-shot coating while periodically inverting the fibers and giving twists that are alternately reversed left and right in the longitudinal direction.

In addition, by arbitrarily changing the outer diameter of the molded pipe formed by the plastic tape and the number of pipes according to the number of optical fibers to be stored, it is possible to form the outer diameter of the multi-core optical cable to an optimally small diameter. can.

The molded pipe of the present invention has the functions of preventing the coating resin from adhering to the optical fiber when applying the bracket coating, preventing the influence of heat, and making it possible to take out the optical fiber at a desired location using a tear string.

〔Effect of the invention〕

As explained above, the method for manufacturing a multi-core optical cable of the present invention requires a single assembly and coating process, whereas the conventional method requires two processes: assembly and coating. Since this is a method, it is possible to manufacture multi-core optical cables with a small amount of capital investment and equipment installation area, and it is possible to achieve economy by reducing manpower and flexibility in meeting delivery deadlines by shortening manufacturing time.

In addition, the multi-core optical cable of the present invention does not require optical fibers because the tear string is housed inside the molded pipe made of plastic with a thickness of 0.1 mm or more and Q.3 mm or less. Since the molded pipe can be easily removed from the molded pipe at a suitable location, and each molded pipe is individually protected by a collective coating, it has excellent post-branching properties and can be easily withdrawn by each user.

Furthermore, the multi-core optical cable of the present invention has a cushioning effect and is effective in maintaining mechanical strength because it forms a gap as large as the molded pipe housing the optical fiber against external forces. It is.

Furthermore, when the multi-core optical cable of the present invention is applied to a multi-core optical cable installed in a positive road such as a waterway, the diameter of the molded pipe formed with plastic tape can be appropriately set to maintain buoyancy to the extent that the cable does not sink in the water. By providing this, it is possible to adopt an economical pouring method that can be installed using simple installation equipment, in a short period of time, and with a small number of people, which is effective.

Further, the structure in which the optical fiber housing molded pipe is twisted and covered all at once is effective against the influence of elongation strain on the optical fiber and the flexibility of the optical cable.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of an embodiment of the multi-core optical cable of the present invention.
FIG. 2 is a process outline diagram of the multi-core optical cable manufacturing method of the present invention. 1... Tensile strength body, 2... Molded pipe, 3... Optical fiber, 4... Tear string, 5... - Bracket coating, 20
... Supply stand, 21 ... Tensile strength body, 22.
...Molded pipe, 221...Plastic tape, 2
3...Optical fiber, 24...Tear string, 25...
- Bracket coating, 26... Molding die, 27... Plastic molding machine, 200... Multi-core optical cable Patent applicant Sumitomo Electric Industries, Ltd. (1 other person) Agent Patent attorney Kugobe Tamamushi

Claims (5)

[Claims] (1) A plurality of optical fibers housed around the central tensile strength member with a thickness of 0.1 mm or more, 0.1 mm or more.
A multi-core optical cable, characterized in that it has a structure in which molded pipes made of plastic tape with a thickness of 3 mm or less are arranged, and the central tensile strength member and the molded pipes are collectively covered. (2) The multi-core optical cable according to claim 1, wherein the molded pipe made of a plastic tape with a thickness of 0.1 mm or more and 0.3 mm or less accommodates a tear string together with the optical fiber. (3) The molded pipe made of plastic tape with a thickness of 0.1 mm or more and 0.3 mm or less is characterized in that one direction of the molded pipe is periodically reversed alternately left and right in the longitudinal direction of the optical cable. The multi-core optical cable according to claim 1 or 2. (4) In a method for manufacturing a multi-core optical cable, an optical fiber, a tear string, a plastic tape with a thickness of 0.1 mm or more and a thickness of 0.3 mm or less, and a tensile strength member are placed on a supply stand, and the tensile strength member is A molding die for forming the plastic tape into a pipe shape while accommodating the optical fiber and tearing string is arranged around the tensile strength body, The plastic tape was passed through a plastic molding machine with a molded pipe formed into a pipe shape containing the optical fiber and tear string placed therein, and the molded pipe was placed around the tensile strength body by the plastic tape molding machine. A method for manufacturing a multi-core optical cable, characterized in that the multi-core optical cables are collectively coated in a state of the molded pipe, and the multi-core optical cables formed by the molded pipes are assembled and collectively coated in one step. (5) The method includes the step of giving a twist to the molded pipe by periodically inverting the molded pipe made of plastic tape containing the optical fiber and the tear string in the longitudinal direction of the optical cable, alternately left and right. 5. The method for manufacturing a multi-core optical cable according to claim 4.