JP4495123B2 - Optical fiber composite ground wire - Google Patents

Description

  The present invention relates to an optical fiber composite ground wire.

  In recent years, with the increasing power demand, information such as maintenance management has become more and more complicated, and an optical fiber composite aerial system combining the functions of the transmission line and the communication line by combining the optical fiber with the overhead line of the transmission line. Ground wire (OPGW) has been developed and put into practical use.

  As this optical fiber composite aerial ground wire, for example, as shown in FIG. 4, an aluminum spacer 3 having a plurality of spiral grooves 4 formed in the longitudinal direction and accommodated in the aluminum tube 2, and in each spiral groove 4. There is a fixed aerial ground wire in which a plurality of aluminum-coated steel wires 6 are twisted together in an optical fiber unit 1 having a plurality of optical fibers 5 to be housed. In addition, all the aluminum described in this specification contains an aluminum alloy.

Further, as shown in FIG. 5, a plurality of optical fibers 5 loosely housed in the stainless steel tube 8 and a jelly compound filled so as to fill the gap between the optical fibers 5 in the gaps in the stainless steel tube 8. The loose tube type optical fiber unit 7 having 9 is a stainless loose tube type overhead ground wire obtained by twisting a plurality of aluminum-coated steel wires 6 or galvanized steel wires.
JP 11-242146 A

  Among the above-mentioned optical fiber composite aerial ground wires, in particular, the stainless loose tube type aerial ground wire shown in FIG. 5 has a relatively simple structure and is easy to manufacture, easily adapts to multi-core optical fibers, and has a tensile stress. It is widely used overseas because it easily relieves distortion of optical fibers due to the action of bending stress.

  However, when this type of optical fiber composite ground wire is used in a corrosive environment surrounded by the sea like Japan, an aluminum-coated steel wire or a galvanized steel wire in the portion of the optical fiber unit in direct contact with the stainless steel pipe There is a greater risk that the aluminum or zinc will corrode and the internal steel wire will be exposed. For this reason, there is a problem that the mechanical and electrical characteristics of the optical fiber composite ground wire are greatly impaired during long-term use, and it has not been widely used in Japan.

  The present invention solves the above problems, improves the corrosion resistance of the aluminum-coated steel wire or galvanized steel wire, maintains good mechanical and electrical characteristics of the optical fiber composite ground wire, and stably for a long time. An object is to provide an optical fiber composite ground wire that can be used.

In order to achieve the above object, the present invention provides a plurality of optical fibers housed loosely in a stainless steel tube, and a jelly compound filled so as to fill a gap between the optical fibers in a gap in the stainless steel tube. In an optical fiber composite ground wire in which a plurality of aluminum-coated steel wires or galvanized steel wires are twisted together with a loose tube type optical fiber unit having an optical fiber unit, the optical fiber unit connects one stainless steel tube to the outside of the aluminum It is formed in a tube loosely, and the twisted layer formed of the plurality of aluminum-coated steel wires or galvanized steel wires has an inner and outer two-layer structure, and an inner aluminum-coated steel wire or The galvanized steel wire has a segment shape, and the inner aluminum-coated steel wire or the galvanized steel wire is in contact with the aluminum outer tube.

  According to the optical fiber composite ground wire having the above configuration, the aluminum outer tube of the loose tube type optical fiber unit is in direct contact with the aluminum-coated steel wire or the galvanized steel wire. Then, the ionization tendency in the electrification row between the two metals in contact with each other is equal or close, so that it is in direct contact with the aluminum outer tube of the optical fiber unit during use of the optical fiber composite ground wire. Corrosion of aluminum or zinc in the aluminum-coated steel wire or galvanized steel wire in the portion can be suppressed. Therefore, the corrosion resistance of the aluminum-coated steel wire or galvanized steel wire is improved so that the steel wire is not exposed, the mechanical and electrical characteristics of the optical fiber composite ground wire are maintained well, and the corrosive environment is maintained. It can be used stably for a long time even in severe places.

  According to the optical fiber composite ground wire of the present invention, the loose tube type optical fiber unit is formed by housing a stainless steel pipe in an aluminum outer pipe, so that the aluminum outer pipe is the aluminum-coated steel wire or galvanized steel. It will be in direct contact with the line. As a result, during use of the optical fiber composite aerial ground wire, it is possible to suppress erosion of aluminum or zinc of the aluminum-coated steel wire or the galvanized steel wire in the portion directly contacting the aluminum outer tube of the optical fiber unit. As a result, the corrosion resistance of the aluminum coated steel wire or galvanized steel wire is improved and the steel wire is not exposed, and the mechanical and electrical characteristics of the optical fiber composite ground wire are maintained well. It can be used stably for a long time even in harsh environments.

  Further, by storing the stainless steel pipe in the aluminum outer pipe, it becomes possible to store the stainless steel pipe in the aluminum outer pipe while forming the aluminum outer pipe. Therefore, it is possible to easily prevent direct contact between the stainless steel pipe and the aluminum-coated steel wire or the galvanized steel wire at a lower cost than that in which the outer peripheral surface of the stainless steel pipe is provided with an aluminum coating layer by extrusion or the like. The cost of the fiber composite overhead ground wire can be reduced.

  Embodiments of the present invention will be described in detail with reference to the drawings. The optical fiber composite aerial ground wire shown in FIG. 1 is a plurality of optical fibers 5 that are loosely (loosely) housed in a stainless steel tube (SUS tube) 8 and are primarily coated with UV resin (ultraviolet curable resin). And a jelly compound 9 made of, for example, silicon or polybden, which is filled with a gap in the stainless steel tube 8 so as to fill the gap between the optical fibers 5 and has excellent waterproofness and stress relaxation characteristics, for example, Furthermore, a stainless steel tube type optical fiber unit 11 formed by housing the stainless steel tube 8 in an aluminum outer tube 10 is provided.

  When the stainless steel pipe 8 is housed in the aluminum outer pipe 10, it is performed as follows. That is, a plurality of optical fibers 5 are stored loosely in advance in a stainless steel tube 8 and filled with a jelly compound 9. Next, while aluminum tape is vertically attached to the stainless steel pipe 8, the tape is formed in a circular tube shape on the outer periphery of the stainless steel pipe 8, and both side edge butt portions of the aluminum tape are welded to form the aluminum outer pipe 10. The stainless steel tube 8 is housed loosely inside. Thereafter, the aluminum outer tube 10 may be reduced in diameter by a reduced diameter die or a forming roll or the like continuously or in a separate step as necessary.

  Thus, by housing the stainless steel tube 8 in the aluminum outer tube 10, it becomes possible to accommodate the stainless steel tube 8 inside the aluminum outer tube 10 while forming the aluminum outer tube 10. It is possible to easily prevent direct contact between the stainless steel pipe 8 and the aluminum-coated steel wire 6 or galvanized steel wire, which will be described later, at a lower cost than that provided with an aluminum coating layer by extrusion or the like.

  The optical fiber unit 11 having the above-described structure is further formed by twisting a plurality of (six) aluminum-coated steel wires 6 concentrically on the outer periphery of the unit 11 as a center. Get a line. In addition, you may make it twist around the outer periphery of the optical fiber unit 11 using a galvanized (a thermal spraying is included. The same hereafter) steel wire instead of the aluminum covering steel wire 6. FIG.

According to the optical fiber composite ground wire having the above configuration, the aluminum outer tube 10 of the loose tube type optical fiber unit 11 is in direct contact with the aluminum-coated steel wire 6 or the galvanized steel wire, and the stainless steel tube 8 is No contact with the aluminum-coated steel wire 6 or the galvanized steel wire. Then, since the ionization tendency in the electrification row between the two metals in contact with each other becomes equal or approaches, the optical fiber unit 11 is directly connected to the aluminum outer tube 10 during use of the optical fiber composite ground wire. Corrosion of aluminum or zinc of the aluminum-coated steel wire 6 or the galvanized steel wire in the contact portion can be suppressed. As a result, the corrosion resistance of the aluminum coated steel wire 6 or the galvanized steel wire is improved and the internal steel wire is not exposed, and the mechanical and electrical characteristics of the optical fiber composite ground wire are maintained well. The performance is stable and the reliability is improved.

  The optical fiber composite ground wire shown in FIG. 2 is a modification of the optical fiber composite ground wire shown in FIG. In this optical fiber composite ground wire, a plurality of aluminum-coated steel wires 6 twisted on the outer peripheral surface of the optical fiber unit 11 have an inner and outer two-layer structure, and the cross-sectional shape of the inner aluminum-coated steel wire 6 is a segment. It is a shape and the cross-sectional shape of the outer aluminum-coated steel wire 6 is formed in a circular shape. A galvanized steel wire may be used instead of the aluminum-coated steel wire 6. Other configurations are the same as those shown in FIG.

  The optical fiber composite ground wire shown in FIG. 3 is a further modification of the optical fiber composite ground wire shown in FIG. The optical fiber composite ground wire is formed by twisting three optical fiber units 11 and four aluminum-coated steel wires 6 to form a stranded wire core 12. The aluminum wire 13 is twisted together. Note that an aluminum-coated steel wire 6 may be used instead of the aluminum wire 13. Further, instead of the aluminum-coated steel wire 6 and the aluminum-coated steel wire 6 of the stranded wire core 12, a galvanized steel wire may be used. Other configurations are the same as those shown in FIG.

It is a cross-sectional view which shows one Embodiment of this invention. It is a cross-sectional view which shows other embodiment of this invention. It is a cross-sectional view showing still another embodiment of the present invention. It is a cross-sectional view which shows an example of the conventional optical fiber composite aerial ground wire. It is a cross-sectional view showing another example of a conventional optical fiber composite ground wire.

Explanation of symbols

5 Optical fiber 6 Aluminum coated steel wire 8 Stainless steel tube 9 Jelly compound 10 Aluminum outer tube 11 Optical fiber unit 12 Stranded wire core 13 Aluminum wire

Claims (1)

A loose tube type optical fiber unit having a plurality of optical fibers housed in a stainless steel tube loosely and a jelly compound filled so as to fill a gap between the optical fibers in a gap in the stainless steel tube. In an optical fiber composite ground wire in which two aluminum-coated steel wires or galvanized steel wires are twisted,
The optical fiber unit is formed by loosely accommodating one stainless steel tube in an aluminum outer tube ,
The twisted layer formed of the plurality of aluminum-coated steel wires or galvanized steel wires has an inner and outer two-layer structure, and the inner aluminum-coated steel wire or galvanized steel wire has a segment shape,
An optical fiber composite ground wire, wherein the inner aluminum-coated steel wire or galvanized steel wire is in contact with the aluminum outer tube .

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