JPH0126131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an optical fiber composite power line, the purpose of which is to improve the reliability of the optical fiber core against elongation of the optical fiber composite power line.

Optical fiber cables have the feature of not being affected by interference caused by induced electromagnetic fields, so they can be integrated with power lines to form communication lines, and cables with various composite structures have already been proposed. There is.

However, this type of cable is known to elongate by around 0.3% due to large tension being applied to the cable during installation or installation. On the other hand, it is known that the lifespan of optical fiber is significantly shortened under stress-applied conditions, and for this reason, when manufacturing this type of composite cable, the optical fiber cable must be pre-coated to accommodate the elongation of the power cable. On the other hand, a structure has been proposed in which a slack is provided so that no tension is applied.

The present invention provides a method to provide slack necessary for the optical fiber cable when laying or constructing the optical fiber composite power line as described above, between the optical fiber cable core to be twisted and the conductor. This relates to a manufacturing method in which an optical fiber cable core and a power conductor are twisted and assembled while creating a temperature difference so that the conductor reaches a high temperature.

The embodiments shown in FIGS. 1 and 2 will be explained below. In FIG. 1, reference numeral 2 denotes an optical fiber cable core in which a plurality of optical fiber cores are twisted together in advance, and is supplied from a reel 1. As shown in FIG. Reference numeral 3 denotes a cooling device that ends just before the twisting position, and the optical fiber cable core 2 coming out of the reel 1 passes through the cooling device 3, and passes through the cooling device 3 just before the twisting position. 5 is a conductor, which is supplied by a plurality of rotating reels 4, respectively. Conductors 5 fed out from a plurality of rotating reels 4 are twisted around the optical fiber cable core 2 and wound around a winding drum 8 as an optical fiber composite power line 7.

At this time, as mentioned above, the optical fiber cable core 2 is cooled until just before being twisted, and at the same time, although not shown, if each conductor 5 is heated while being twisted, a large temperature difference can be created between the two. This is extremely effective because the twisting is performed with The temperature difference when the conductor 5 and the optical fiber cable core 2 are twisted and assembled should be selected depending on the conductor material, the structure of the fiber cable core 2, etc. For example, if the conductor 5 is copper and the fiber cable core 2 has a structure in which a plurality of optical fiber cores are twisted together, the linear expansion coefficients of the copper and the optical fiber cable core are almost equal, 1.7×10 ^-5 /°C, so if the temperature difference is 175°C or more, it is possible to create a cable in which the optical fiber does not stretch even when the cable stretches by 0.3% or more.

FIG. 2 shows another embodiment.

In the figure, the cooling device 3 is large enough to cool the reel 1 around which the optical fiber cable core 2 is wound.
It is also possible to adopt a method of surrounding and heating a plurality of rotating reels 4 wound with A system equipped with a heating device is effective.

The twisting process is the same as that described in FIG. If necessary, an insulating coating is applied to the surface of the optical fiber composite power line twisted and assembled in this way, but in this respect it is no different from a normal power line.

As mentioned above, in the present invention, by twisting and assembling the conductor and the optical fiber cable core with a temperature difference created so that the conductor is hotter than the conductor, the conductor strands, which are hot immediately after the twisting, are removed. The length of the fiber at low temperature is the same as that of the fiber at low temperature, but when it returns to room temperature and is thermally contracted, the fiber optic cable core may meander in the free space inside the twisted conductor, or the twisted state of the optical fiber cable core (twisting degree, twisting As a result of the change in the optical fiber cable core (diameter), slack will occur in the optical fiber cable core.

Therefore, in such an optical fiber composite power line, even if a large tension is applied during installation or erection, the optical fiber core cable has an appropriate slack to compensate for the elongation of the conductor. unaffected.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the invention. FIG. 2 shows another embodiment. 1... Reel for optical fiber cable core, 2...
...Optical fiber cable core, 3...Cooling device, 4
...Rotary reel for supplying conductor, 5...Conductor, 6...
Heating device, 7... Optical fiber composite power line, 8...
Winding drum.

Claims (1)

[Claims] 1. A method for manufacturing an optical fiber composite power line, which comprises twisting and assembling a plurality of high-temperature conductors around a low-temperature optical fiber cable core. 2. The optical fiber according to claim 1, characterized in that a plurality of high temperature conductors heated by a heating device are twisted and assembled around a low temperature optical fiber cable core cooled by a cooling device. Method of manufacturing composite power line.