JPH10197765A - Optical fiber cable for pneumatic force feeding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable for pneumatic force feeding with high pneumatic force feeding characteristics. SOLUTION: Tensile strength bodies 34a and 34b are provided on both sides of a coated optical fiber ribbon surface long-diameter surface along a ribbon of coated optical fibers 33 to increase the rigidity without increasing a cable external diameter. Further, the sectional shape is circular, so the airtight structure of an optical fiber cable guide-in part for pneumatic force feeding from an atmospheric pressure part to a high-pressure part. Therefore, when an optical fiber cable like this is forcibly fed into a tube with air, the optical fiber cable can be fed speedily without damaging the inside of a tube with small curvature or long tube since the optical fiber cable 41 is thin and sectioned circularly and includes the tensile strength bodies 34a and 34b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic optical fiber cable for pneumatically feeding air into a previously piped tube.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional example of an optical fiber cable for pneumatic feeding.

[0003] An optical fiber cable for pneumatic feeding 1 has a single tear cord 3 and five optical fiber strands 2b to 2f gathered around the optical fiber strand 2a, and a resin is attached to the outer periphery thereof. And a sheath 7 is formed on the outer periphery of the jacket 6 to form a circular cross-sectional shape (outer diameter 6 mm or less).

FIG. 5 is a sectional view of a pneumatic tube cable for pneumatically piping the optical fiber cable for pneumatic transmission shown in FIG.

The air pressure feeding tube cable 8 is formed by assembling six tension members 9b to 9g on the outer periphery of one tension member 9a, covering the tension members 9b to 9g with a resin 10, and forming a circular cross-sectional shape. Six tubes (inner diameter 6 mm, outer diameter 8 mm) 11a to 11f larger than the outer diameter of the sending optical fiber cable 1 (see FIG. 4) are assembled, and a presser winding 12 is applied to the outer periphery of the tubes 11a to 11f, and a presser winding is performed. A sheath 13 is provided on the outer periphery of the sheath 12.

[0006] The wiring method using the pneumatic optical fiber cable 1 shown in Fig. 4 and the pneumatic tube cable 8 shown in Fig. 5 is generally called an optical fiber pneumatic method and is widely used. ing.

FIG. 6 is a conceptual diagram of an optical fiber pneumatic feeding device for explaining an optical fiber pneumatic feeding method.

[0008] One end (left side in the figure) of the tube 11 of the air-pneumatic tube cable 8 is mounted on the pumping head 14 and the optical fiber cable 1 wound around the bobbin 15 is inserted into the tube 1 from the pumping head 14. insert. In this state, the compressor air dryer 1
When the tube 6 is operated, high-pressure air is supplied into the tube 11, and the optical fiber cable 1 is pressure-fed by the air flow.

The feature of this method is that a cable in which tubes are assembled in advance is routed to a route where a line is deemed necessary, and the tubes are later connected to each other using a dedicated tube connector when an optical line is required. Make a route,
It is possible to pump the required number of optical fibers into the tube, and it is not necessary to connect the optical fibers at the branch point of the tube cable. Also, since removal and re-laying of the optical fiber in the tube is easy, it can be said that the method is rich in workability, expandability, and economy.

As an optical fiber cable for pressure feeding into a tube, an air pressure optical fiber cable shown in FIG. 4 is generally used, but recently two or four optical fiber wires are arranged in a line. It is also actively practiced to apply a further coating to the collectively coated tape core wire and pressure-feed the cable.

FIGS. 7 to 9 are sectional views showing a conventional example of an optical fiber cable for pneumatic feeding using a tape core.

The optical fiber cable 17 for pneumatic feeding shown in FIG. 7 is formed by covering a four-core tape 18 with a jacket 19 and coating the outer periphery of the jacket 19 with a sheath 20 to have a circular cross section. .

The optical fiber cable 21 for pneumatic feeding shown in FIG. 8 has strength members 23a, 23a, 4a along the four-core ribbon 22 so as to be located on both sides of the cross-section minor diameter surface of the four-core ribbon 22. 23b is arranged, both are covered with a jacket 24 made of resin, and the outer periphery thereof is covered with a sheath 25 to form a circular cross section.

The optical fiber cable 26 for pneumatic feeding shown in FIG. 9 has strength members 28 along the four-core tape 27 so as to be located on both sides of the short-diameter surface of the cross-section of the four-core tape 27.
a and 28b are arranged, and both are made of a resin jacket 2
9 and the outer periphery thereof is covered with a sheath 30 to form an elliptical cross section.

[0015]

In the case where the optical fiber cable 17 for pneumatic feeding shown in FIG. 7 is pneumatically fed by using the apparatus shown in FIG. 6, the in-tube pressure feeding characteristics and the heat cycle characteristics (temperature characteristics) are used. Both were relatively good,
Since the rigidity of the cable itself is relatively weak, it has been difficult to obtain good pumping characteristics.

When the optical fiber cable 21 for pneumatic feeding shown in FIG. 8 is pneumatically fed by using the apparatus shown in FIG. 6, tensile strength members 23a, 23a, Since the cable 23b was used, the rigidity of the cable itself was strong, but as the cable outer diameter increased, the weight and air resistance also increased, resulting in inferior pumping characteristics.

Further, when the optical fiber cable 26 for pneumatic transmission shown in FIG. 9 is pneumatically transmitted by using the apparatus shown in FIG. 6, the cross section of the cable is elliptical, so that the optical fiber for pneumatic transmission on the apparatus side is used. There is a problem that the airtight structure of the fiber cable introduction section (the introduction section from the atmospheric pressure section to the high pressure section) becomes complicated.

An object of the present invention is to solve the above-mentioned problems and to provide an optical fiber cable for pneumatic feeding having high pumping characteristics.

[0019]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a plurality of optical fibers are arranged in a tape, and the outer circumference of a tape is covered with a jacket, and the outer circumference of the jacket is covered with a sheath. In an optical fiber cable for pneumatic feeding for feeding an optical fiber cable into a previously piped tube, a tensile strength member is provided along the tape core wire so as to be located on both sides of the tape core wire cross-section long diameter surface. Things.

In addition to the above construction, the optical fiber cable for pneumatic feeding of the present invention comprises a plurality of tape cores bundled in parallel, and a tensile strength member is provided along the tape cores so as to be located on both sides of the tape core cross-section long diameter surface. May be provided.

In addition to the above configuration, it is preferable that the strength member of the optical fiber cable for pneumatic feeding of the present invention is FRP.

According to the present invention, it is possible to increase the rigidity without increasing the outer diameter of the cable by providing the tensile members along the tape core so as to be located on both sides of the long-diameter surface of the cross section of the tape core. it can. Moreover, since the cross-sectional shape is circular, the airtight structure of the optical fiber cable introduction portion for air pressure transmission from the atmospheric pressure portion to the high pressure portion on the side of the pressure feeding device is simplified. Therefore, when such an optical fiber cable for pneumatic feeding is pneumatically fed into a tube, the bending rate of the tube is small because the optical fiber cable for pneumatic sending is thin, has a circular cross section, and has a built-in strength member. Even when the tube is long or long, the tube can be quickly pumped without damaging the inside of the tube, and high pumping characteristics can be obtained.

When a plurality of tape cores are bundled in parallel, the transmission capacity of an optical signal can be increased.

Further, when the tensile strength member is FRP, the workability and flexibility of the optical fiber cable for pneumatic feeding can be improved, and the pumping characteristics can be further improved.

[0025]

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

FIG. 1 is a sectional view showing an embodiment of an optical fiber cable for pneumatic feeding according to the present invention.

The optical fiber cable for pneumatic feeding 31
The optical fiber strands 32a to 32d (four, but not limited to four in the figure) are arranged in a tape shape and covered with resin to form an elliptical cross-section, and both sides of the tape core cross-section major surface , A strength member 34a, 34b provided along the tape core 33 (perpendicular to the paper surface), a jacket 35 covering the tape core 33 and the strength members 34a, 34b, and a sheath covering the outer periphery of the jacket 35. 36 and formed in a circular cross-sectional shape.

The tensile strength members 34a and 34b are positioned so that they are located on both sides of the major surface of the cross section of the tape core wire 33.
3, the rigidity can be increased without increasing the outer diameter of the optical fiber cable 31 for pneumatic transmission while keeping the circular cross-sectional shape. For this reason, the airtight structure of the optical fiber cable introduction part for air pressure feeding from the atmospheric pressure part to the high pressure part on the side of the pressure feeding device is simplified.

Therefore, when such an optical fiber cable for air pressure transmission 31 is air-fed into the tube 11, the outer diameter of the optical fiber cable for air pressure transmission is small (FIGS. 8 and 9).
(Compared with the cables 21 and 26 shown in FIG. 2), the cross section is circular and the strength member is built in, so that even if the bending rate of the tube is small or long, the inside of the tube is not damaged and quickly. Pumping is possible, and high pumping characteristics are obtained.

When the tensile members 34a and 34b are made of FRP, the workability and flexibility of the optical fiber cable for pneumatic feeding can be improved, and the pumping characteristics can be further improved.

[0031]

Next, an embodiment of an optical fiber cable for pneumatic feeding according to the present invention will be described with reference to numerical values, but the present invention is not limited thereto.

A single mode optical fiber having a cladding diameter of about 125 μm is coated with an ultraviolet curable resin to reduce the outer diameter to about 2 μm.
50 μm, four optical fiber strands are arranged side by side to form a tape, and coated with an ultraviolet curable resin to form an elliptical cross-section, thereby forming a four-core tape core of about 1.1 mm × about 0.3 mm. can get.

The F as a tensile strength member having an outer diameter of about 210 μm is located on both sides of the long diameter surface of the cross section of the four-core tape.
The RPs are arranged one by one, and an ultraviolet curable resin as a jacket is applied thereon so that the cable cross section becomes circular. Furthermore, by coating with foamed polyethylene as a sheath, the outer diameter is about 2.2 mm, and the mass is about 3.2 g.
/ M of the air-fed optical fiber cable.

The air-fed optical fiber cable is connected to a tube route having a tube inner diameter of about 4.5 mm and a tube route of about 1400 m.
Was pumped at a pressure of about 10 kgf / cm ² , and the pumping operation was completed in about 2 hours. Also, there was no problem with heat cycle characteristics (temperature characteristics).

(Modification) FIG. 2 is a sectional view showing a modification of the optical fiber cable for pneumatic feeding of the present invention. FIG.
The same members as those of the optical fiber cable for pneumatic transmission shown in FIG.

The difference from the embodiment shown in FIG. 1 is that a two-core tape is used as the tape core. The optical fiber cable 37 for pneumatic feeding has two core optical fibers 32a and 32b arranged in a tape shape and covered with a resin to form an elliptical cross-sectional shape. Strength members 34a, 34b provided along the tape core 330 (perpendicularly to the paper surface) so as to be positioned;
A jacket 35 covering the tape core 330 and the tensile members 34a, 34b, and a sheath 3 covering the outer periphery of the jacket 35
6 and formed into a circular cross-sectional shape.

The optical fiber cable for air pressure transmission 37 having such a structure can also obtain high pressure transmission characteristics.

FIG. 3 is a sectional view showing another modification of the optical fiber cable for pneumatic feeding of the present invention.

The difference from the embodiment shown in FIG. 1 is that two tape cores are used.

The air pressure feeding optical fiber cable 38 is composed of two tape bundles 33a and 33b bundled in parallel, and a tensile strength member 34a provided along the tape bundles 33a and 33b on both sides of the long-diameter surface of the tape bundle. , 34b and both tape cores 3
A jacket 35 covering the 3a, 33b and both the tensile members 34a, 34b, and a sheath 36 covering the outer periphery of the jacket 35
And formed in a circular cross-sectional shape.

The optical fiber cable 38 for air pressure transmission having such a structure can also obtain high pressure transmission characteristics and can increase the transmission capacity of an optical signal.

[0042]

In summary, according to the present invention, the following excellent effects are exhibited.

Since the tensile strength members are provided on both sides of the long-diameter surface of the tape core section and along the tape core, an optical fiber cable for pneumatic feeding with high pumping characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an optical fiber cable for pneumatic feeding according to the present invention.

FIG. 2 is a sectional view showing a modified example of the optical fiber cable for pneumatic feeding according to the present invention.

FIG. 3 is a sectional view showing another modified example of the optical fiber cable for pneumatic feeding of the present invention.

FIG. 4 is a sectional view showing a conventional example of an optical fiber cable for pneumatic feeding.

FIG. 5 is a sectional view of a tube cable for pneumatic feeding for piping the optical fiber cable for pneumatic feeding shown in FIG. 4;

FIG. 6 is a conceptual diagram of an optical fiber pneumatic feeding device for explaining an optical fiber pneumatic feeding method.

FIG. 7 is a sectional view showing a conventional example of an optical fiber cable for pneumatic feeding using a tape core.

FIG. 8 is a cross-sectional view showing a conventional example of an optical fiber cable for pneumatic feeding using a tape core.

FIG. 9 is a cross-sectional view showing a conventional example of an optical fiber cable for pneumatic feeding using a tape core.

[Explanation of symbols]

 31 optical fiber cable for pneumatic feeding 32a to 32d optical fiber 33 tape core 34a, 34b strength member 35 jacket 36 sheath

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Watanabe 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Factory, Hitachi Cable Co., Ltd. Hitachi Electric Cable Co., Ltd. Hidaka Factory (72) Inventor Shinichi Sasaki 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable, Inc. Hidaka Factory

Claims (3)

[Claims] 1. An optical fiber cable in which a plurality of optical fiber strands are arranged in a tape shape, the outer circumference of a tape core wire is covered with a jacket, and the outer circumference of the jacket is covered with a sheath, and an optical fiber cable is pneumatically fed into a previously piped tube. An optical fiber cable for pneumatic feeding, characterized in that tensile strength members are provided along both sides of the tape core so as to be located on both sides of the long-diameter surface of the tape core cross section. 2. The pneumatic feeding device according to claim 1, wherein a plurality of the tape cores are bundled in parallel, and a tensile strength member is provided along the tape cores so as to be located on both sides of the long-diameter surface of the tape core cross section. Fiber optic cable. 3. The optical fiber cable for pneumatic feeding according to claim 1, wherein the tensile member is FRP.