JPH11213773A - Pipe storage type metal cable and method for switching from metal communication system to optical communication system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe-housing type metal cable which facilitates switching from a metal communication system to an optical communication system, and a method for switching from the metal communication system to the optical communication system using the same. SOLUTION: As a pipe storage type metal cable having at least one pipe 2 in which a metal core wire 1 is housed, a metal cable capable of pulling out the metal core wire 1 from the pipe 2 is used. As a method of switching to the optical communication system, a method is used in which the metal core wire 1 is pulled out from the pipe-housing type metal cable, and the optical fiber core wire or the optical fiber unit is drawn in and replaced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe-housing type metal cable used for information communication and a method for switching from a metal communication method to an optical communication method using the same.

[0002]

2. Description of the Related Art Conventionally, a metal communication system using a metal cable has been used as a communication system used in telephones and the like. However, recently, long distance transmission is possible and transmission capacity is large. Switching to an optical communication system using an optical fiber cable is being promoted in a trunk system connecting telephone offices. Also, for subscriber systems connecting a telephone station to general homes and offices, there are great advantages such as an increase in transmission capacity and a non-relay operation by switching to an optical communication system.

However, when switching from a metal communication system using a metal cable to an optical communication system using an optical fiber cable, it is necessary to re-lay the optical fiber cable or additionally lay an optical fiber cable. . In particular, distribution cables in ordinary houses and apartment houses are often embedded in walls, and it is extremely difficult or impossible to replace the distribution cables. In addition, even in the case of additional laying, it is necessary to newly provide a through-hole for laying a cable in a house wall or the like, or to wire a cable to a visible portion of an indoor wall or the like, which significantly impairs the appearance of the house wall or the like. In addition, there arises a problem that the construction is troublesome.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pipe-housing type metal cable which facilitates switching from a metal communication system to an optical communication system, and from a metal communication system using the same to an optical communication system. To provide a switching method.

[0005]

The object of the present invention is to provide, as a pipe-storing type metal cable having at least one pipe in which a metal core wire is housed, a cable capable of pulling out the metal core wire from the pipe, In addition, as a method of switching from the metal communication system to the optical communication system, the problem can be solved by using a method of pulling out a metal core wire from the above-mentioned pipe-storing type metal cable and drawing in and replacing an optical fiber core wire or an optical fiber unit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a cross-sectional view showing an example of a pipe storage type metal cable of the present invention. This pipe storage type metal cable,
Metal core 1 and pipe 2 containing metal core 1
And a sheath 3 for covering the pipe 2.

[0007] The metal core wire 1 is a pair of metal core wires formed by covering a conductor 4 with an insulator 5.
Examples of the conductor 4 include a copper wire and an aluminum wire, and a copper wire is usually preferably used. Examples of the insulator 5 include polyethylene, polyvinyl chloride, and the like, and polyethylene is generally preferably used.
The metal core wire 1 may be a combination of four metal core wires, a metal wire consisting of two or more metal core wires, or the like.

The pipe 2 is made of a plastic material having a small friction with the metal core wire 1 to be housed and the optical fiber core wire to be inserted, and is formed so that the inside is hollow. The shape, size, and the like of the pipe 2 are set according to the use of the pipe-storing type metal cable, the size of the cross-sectional area of the metal core 1, the optical fiber, and the like. In particular, the size of the cavity inside the pipe 2 is set so that there is a sufficient gap between the housed metal core wire 1, the optical fiber core wire, etc. and the inner wall of the pipe 2. It is necessary to make it possible to smoothly pull out the optical fiber and to smoothly pull in the optical fiber.

Examples of the material of the pipe 2 include polyolefins such as polyethylene and polypropylene, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, fluorine resins such as polychlorotrifluoroethylene and polyvinyl fluoride, and methyl resin. Examples thereof include silicone resins such as silicone and phenyl silicone, and silicone-added polyethylene. Of these, silicone-added polyethylene is preferably used in terms of slipperiness, rigidity, and cost.

[0010] By using a plastic material having a small friction with the metal core wire 1 and the optical fiber core wire as described above as the material of the pipe 2, the metal core wire 1 is pulled out from the metal cable accommodated in the pipe. , And optical fiber cords can be smoothly drawn in.

The sheath 3 covers the pipe 2 to protect the pipe 2, and is made of a material that is mechanically strong and has excellent water resistance, moisture resistance and chemical resistance. The material of the sheath 3 is selected depending on the use of the pipe-storing type metal cable, and is not particularly limited. For example, polyvinyl chloride, polyethylene, fiber reinforced polyethylene, or the like is used.

As a method of housing the metal core wire 1 in the pipe 2, for example, a method of housing the metal core wire 1 in the pipe 2 simultaneously with the extrusion of the pipe 2 in the manufacturing process of the pipe 2, After manufacturing the metal core wire 1 and pipe 2
A method of inserting the metal core wire 1 into the pipe 2 at the same time as the extrusion molding of the pipe 2 is used from the viewpoint of labor and the like. Also,
The number of metal core wires 1 stored in the pipe 2 in advance may be two or more. As a method of coating the sheath 3 on the pipe 2, for example, a method of extruding and coating the material of the sheath 3 heated and melted on the pipe 2 by an extruder is used.

Further, as the pipe storage type metal cable of the present invention, a collective cable composed of two or more pipes, a unit type cable having a tensile strength member, or the like may be used. It is possible to use not only for the use of the wiring cable, but also for other uses such as underground cable.

Next, a method for switching from the metal communication system using the pipe-storing type metal cable of the present invention to the optical communication system will be described. FIG. 2 is a cross-sectional view showing an example of a pipe-housing type metal cable in which the metal core wire 1 has been pulled out and the optical fiber core wire 6 has been drawn in and replaced. When it becomes necessary to switch from the metal communication system to the optical communication system, the metal core wire 1 is pulled out of the pipe storage type metal cable laid on the wall or the like, and then the optical fiber core wire 6 is drawn in. Switching to a fiber cable is performed.

The optical fiber core 6 is obtained by applying a secondary coating 8 to an optical fiber 7 in which a silica-based optical fiber is primarily coated with an ultraviolet curable resin or the like. As the ultraviolet curing resin, for example, epoxy acrylate, urethane acrylate, or the like is used. The material of the secondary coating 8 is, for example, nylon 6, nylon 66, or the like.
Polyamides such as polyethylene, etc. are used.

As a method for drawing in the optical fiber core wire 6, an optical fiber core wire 6 is connected to one end of the metal core wire 1, and then the metal end is connected to the other end where the optical fiber core wire 6 is not connected. A method of pulling out the core wire 1 and simultaneously pulling in the optical fiber core wire 6 and a method of feeding the optical fiber core wire 6 by pressurized air into the empty pipe 2 from which the metal core wire 1 has been drawn out. No.

The former metal core wire 1 and optical fiber core wire 6
The method of connecting the metal core wire 1 and the optical fiber core wire 6 at the same time as pulling out the metal core wire 1 does not require a special device or the like.
If the connection between the metal core wire 6 and the optical fiber core 6 is not sufficiently performed, the connection portion may be cut off during the drawing of the metal core wire 1, and it may be difficult to pull in the optical fiber core wire 6. In the latter method of feeding the optical fiber core wire 6 by pressurized air, it is necessary to prepare a device or the like for generating pressurized air. Can be pulled in.

The optical fibers to be drawn in include optical fiber cores in which two or more optical fiber wires 7 are assembled.
An optical fiber unit having a tensile member, an optical fiber unit for pneumatic feeding, or the like may be used. It is also possible to insert two or more optical fiber core wires 6 and optical fiber units into the pipe 2.

In such a pipe-housing metal cable and a method of switching from a metal communication system to an optical communication system using the same, a metal-to-metal connection is performed from a pipe-housing metal cable laid as a metal communication cable. The core wire 1 can be easily pulled out, and the optical fiber core wire 6 can be drawn in and replaced. Therefore, when it becomes necessary to switch from the metal communication system to the optical communication system, a new through-hole for laying a cable in a house wall or the like or wiring a cable to a visible part such as an indoor wall or the like is required. Since the switching from the metal cable to the optical cable can be easily performed without performing the above, the labor of the construction can be reduced, and the cost of the construction can be reduced. Further, even if a problem such as disconnection occurs in the metal core wire 1 stored in the pipe housing type metal cable, the optical fiber core wire 6 inserted later, or the optical fiber unit, the metal core wire 1, the optical fiber Only the fiber core 6 and the optical fiber unit need be replaced.

Hereinafter, examples will be described. (Example) As a metal core wire, a cross-sectional area of 0.25 mm ²
And a pair of metal core wires consisting of a 0.23 mm thick polyethylene insulator covering the copper wire. Then, a pipe having a thickness of 1.0 mm was manufactured by extrusion molding of silicone-added polyethylene,
The metal core wire was housed in the pipe at the same time as the extrusion of the pipe. Further, a sheath made of polyvinyl chloride having a thickness of 1.0 mm was provided by extrusion coating on the pipe,
A pipe storage type metal cable was obtained. The pipe-storing metal cable was laid in a concrete wall having a thickness of about 10 cm over a length of about 20 m.

Next, a bare optical fiber of 125 μm in diameter was coated with a primary coating made of urethane acrylate, and an optical fiber having an outer diameter of 250 μm was further coated with a secondary coating of expanded polyethylene having a diameter of 1.0 mm. An optical fiber cable was prepared. After pulling out the metal core wire from the metal cable accommodated in the pipe, the above optical fiber core wire was pressure-fed into the pipe at an air pressure of 6 kg / cm ² to switch to the optical fiber cable.

In the pipe storage type metal cable of this embodiment, the cable was not crushed by the external pressure even after being laid in the wall. Also, pulling metal twin wires,
The optical fiber cable can be smoothly pumped without any problems, and the time and labor required for switching from metal cables to optical fiber cables has been greatly reduced compared to conventional switching work. In addition, no effect of the switching work was seen on the exterior of the wall.

[0023]

As described above, according to the pipe-housing type metal cable of the present invention and the method of switching from the metal communication system to the optical communication system using the same, the switching work can be facilitated. Excellent effect in terms of workability and cost. In addition, even if an abnormality occurs in the metal core wire stored in the pipe storage type metal cable or the optical fiber core wire inserted later, it is easy to replace the metal core fiber, the optical fiber core, etc. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a pipe storage type metal cable of the present invention.

[FIG. 2] The metal core wire 1 is pulled out and the optical fiber core wire 6 is pulled out.
FIG. 2 is a cross-sectional view showing an example of a pipe-housing type metal cable in which a wire is drawn and replaced.

[Explanation of symbols]

1 ... Metal core wire, 2 ... Pipe, 6 ... Optical fiber core wire

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor: Akio Mogi, 1440, Mukurosaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant (72) Inventor: Koichiro Watanabe 1440, Misaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant ( 72) Inventor Suehiro 1440, Misaki, Sakura-shi, Chiba Prefecture Inside Fujikura Co., Ltd.Sakura Plant (72) Inventor Yoichi Nakamura 2899 Ohara, Oita-shi, Oita Prefecture West Nippon Electric Cable Co., Ltd. (72) Inventor Masakazu Sonoda Oita Prefecture 2899 Ohara, Oita City West Nippon Electric Cable Co., Ltd.

Claims (2)

[Claims] 1. A pipe-storing metal cable having at least one pipe in which a metal twine is stored, wherein the metal twine can be pulled out of the pipe. . 2. A method according to claim 1, wherein a metal core wire is pulled out from the pipe-housing type metal cable, and an optical fiber core wire or an optical fiber unit is drawn in and replaced. Switching method.