JPH09227U - Optical fiber composite cable - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an optical fiber composite cable having flexibility, preventing troubles such as breakage, and facilitating terminal treatment. An optical fiber cable (23) has a structure in which a flexible pipe (20) made of a bellows tube made of metal is accommodated with a gap (D) provided therein, and the flexible pipe (20) and a power cable (30) are sheathed. (1
5) to form a composite cable (10) having an integrated structure, exposing the flexible pipe (20) by a predetermined length from the end of the composite cable (10), and branching the pipe (25) to the end of the flexible pipe (20). ) And / or a fiber optic composite cable fitted with a connector (27).

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to an optical fiber composite cable.

[0002]

[Prior art]

 As shown in FIG. 8, the conventional optical fiber composite cable is constructed by directly integrating, for example, one optical fiber cable 2 and, for example, three electric power cables 3 with a sheath 4 to form a cabtire cable 1. Had formed.

In such a cable, there is a problem such as damage of the optical fiber cable 2 due to abrasion of the sheath 4.

As a means for preventing it, a metal pipe is used as disclosed in JP-A-60-10507, JP-A-57-189577 and JP-A-61-64176 for mechanical strength. Is being implemented. However, if a protective tube is installed and the optical fiber cable is passed through it, there is a problem that the protective tube is crushed and the optical fiber cable is damaged if the bending radius of the protective tube is limited and the bending radius is small. there were. In addition, when it is used with a moving body such as construction machinery, or when the cable is moved by moving it one after another, repeated bending may cause metal fatigue and fracture of the protective tube. .

Further, an optical fiber cable is often used by attaching a connector 27 (FIGS. 5 to 7) at a terminal and connecting it to various optical devices and other cables. This connector installation work requires the work of removing the outermost sheath 4 (Fig. 8), the work of exposing the optical cable, the work of exposing the power cable, and the work of removing the optical cable sheath, exposing the bare fiber, and assembling the connector. Processing work is required. The optical fiber is made of glass or plastic, and its mechanical strength is extremely low compared to the power cable. Therefore, the optical fiber may be broken during such connector mounting work, and careful work is required to prevent this. On the other hand, even if the mechanical strength is improved by using a simple metal pipe as in the above-mentioned known technique, the rigidity of the metal pipe rather interferes with various processing operations and the workability thereof is considerably reduced.

[0006]

[Problems to be solved by the device]

 Therefore, an object of the present invention is to provide an optical fiber composite cable which has flexibility and prevents troubles such as breakage, and which can be easily terminated.

[0007]

[Means for Solving the Problems]

 The optical fiber composite cable according to the present invention has a structure in which the optical fiber cable (23) is housed in a flexible pipe (20) made of a metal bellows tube with a gap (D) provided between the flexible pipe (20) and the power cable. (30) is covered with a sheath (15) to form a composite cable (10) having an integral structure, the flexible pipe (20) is exposed for a predetermined length from the end of the composite cable (10), and the flexible pipe (20) This is a structure in which a branch pipe (25) and / or a connector (27) is attached to the terminal.

In carrying out the present invention, any known metal bellows tube can be used (see, for example, Japanese Utility Model Laid-Open No. 1-57709). Generally, the bellows tube shrinks when a compressive force is applied, but it does not stretch when a tensile force is applied. Since there is a gap between the optical fiber cable and the bellows tube, no tensile or compressive force acts on the optical fiber cable when the bellows tube is bent.

As described above, the optical fiber cable is protected by the flexible pipe and is not exposed even if the sheath is damaged due to abrasion or the like. The use of an accordion tube provides excellent flexibility and allows bending to a small radius of curvature. When the bending stress is removed, it returns to its original shape due to the spring effect, which does not cause bending habits, that is, plastic deformation, and metal fatigue fracture due to repeated bending. Does not occur. At that time, neither tensile stress nor lateral pressure is applied to the optical fiber cable. Therefore, good handleability can be obtained, and it can be used for connection with a moving body.

Even in the terminal processing, even if the sheath is removed and the optical fiber cable is exposed, it is protected by the bellows tube and has flexibility, so that the optical fiber cable can be taken out from the composite cable terminal. It is easy to process and requires no special attention. In addition, even after the connector is attached, the connector is protected by the bellows tube when detaching and attaching, so that it is possible to work safely.

[0011]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1 and FIG. 2, an optical fiber composite cable, that is, a cabtire cable 10, includes a flexible pipe 20 composed of a plurality of (three in the illustrated example) bellows pipes and a plurality of (three in the illustrated example). (For example, the power cable 30) is filled with an intervening rubber 11 and covered with a restraining tape 12, a sheath 13, a reinforcing layer 14 and a sheath 15.

In FIG. 3, the outer circumference of the flexible pipe 20 is covered with an outer jacket 21 and, if necessary, is taped with a tape 22, and two optical fiber cables 23, 23 are shown in the inner hole in the illustrated example. As shown in FIG.

In FIG. 4, the conductor 31 of the power cable 30 is covered with a separator 32 and an insulator 33, and is further taped with a tape 34 if necessary.

Therefore, even if the sheath member such as the sheath 15, the reinforcing layer 14, and the sheath 13 is worn away, the optical fiber cable 23 is protected by the flexible pipe 20, so that the damage is prevented.

When branching the two optical fiber cables 23 at the end of the flexible pipe 20, as shown in FIG. 5, a branch pipe 25 is fitted to the end of the flexible pipe 20 and branched in the branch pipe 25. To do. Then, each of the branched optical fiber cables 23, 23 is covered with a flexible pipe 26 of a constitutional bellows pipe, one end of the pipe 26 is attached to the branch pipe 25, and a connector 27 is fitted to the other end. The optical fiber 24 is attached to.

FIG. 6 and FIG. 7 show another embodiment of the terminal treatment, in which the optical fiber cable 23 is covered with a stainless pipe 26a and a polyvinyl chloride pipe 26b, respectively.

[0018]

[Effect of the invention]

 Since the present invention is configured as described above, it has the following excellent effects.

(A) By using the bellows tube, it is possible to bend to a small radius of curvature with excellent flexibility, and when the bending stress is removed, it returns to its original state due to the spring effect, so that bending bending, that is, plastic deformation does not occur, and repeated bending is performed. Does not cause metal fatigue damage. It can also be used for connection with a moving body or for frequently moving to change the cable routing position. Even if the sheath is damaged, the flexible pipe can prevent the optical fiber cable from being damaged. (B) The process of taking out the optical fiber cable from the composite cable end is easy, and damage can be prevented even when the connector is detached after the connector is assembled.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a block constituting a part of a bellows tube of the optical fiber cable of the present invention.

FIG. 2 is a cross-sectional view perpendicular to the axis of FIG.

FIG. 3 is a cross-sectional view of the flexible pipe at right angles to the axis.

FIG. 4 is a cross-sectional view perpendicular to the axis of the power cable.

FIG. 5 is a sectional view showing one embodiment of a terminal process.

FIG. 6 is a side view showing another example of the terminal processing.

FIG. 7 is a side view showing another example of the terminal processing.

FIG. 8 is a perspective view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Cab tire cable 11 ... Intermediate rubber 12 ... Holding tape 13 ... Sheath 14 ... Reinforcement layer 15 ... Sheath 20 ... Flexible pipe 21 ... Outer jacket 22 ...・ Tape 23 ・ ・ ・ Optical fiber cable 25 ・ ・ ・ Branch pipe 26a ・ ・ ・ Stellence pipe 26b ・ ・ ・ Gear PVC pipe 27 ・ ・ ・ Connector 30 ・ ・ ・ Power cable 31 ・ ・ ・ Conductor D ・ ・ ・ Gap

Claims (1)

[Utility model registration claims] 1. A structure in which an optical fiber cable (23) is housed with a gap (D) provided in a flexible pipe (20) made of a metal bellows tube, and the flexible pipe (20) and the power cable (30) are housed. Sheath (1
5) to form a composite cable (10) having an integral structure, exposing the flexible pipe (20) by a predetermined length from an end of the composite cable (10), and connecting a branch pipe (25) to an end of the flexible pipe (20). And / or a connector (27).