JPH05142432A - Method for laying optical fiber cable to transmission line steel tower - Google Patents

Abstract

PURPOSE:To obtain the method for laying an optical fiber cable to a transmission line steel tower without having the possibility of the slip-off of the optical fiber cable and the increase in transmission loss. CONSTITUTION:This method for laying the optical fiber cable to the transmission line steel tower consists in housing the optical fiber cable 2 in a cable protective pipe 1, raising this cable to the top of the steel tower along the leg of the transmission line steel tower and fixing the cable to the transmission line steel tower. The optical fiber cable 2 is fixed and supported to the steel tower by interposing a cylinder 3 for fixing the steel tower between the adjacent cable protective pipes 1 and 1 at the time of laying the cable protective pipe 1 and the optical fiber cable 2 by using the plastic protective pipes 1 which are previously divided to J 2 parts in the laying route for the optical fiber cable 2 and the cylinder 3 for fixing the steel tower having a fitting hole 5 for the optical fiber cable and having elastic projections 4a to permit the fitting of the optical fiber cable 2 only from one-way side by the bending elastic deformation of the cylinder itself around the fitting hole 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of laying an optical fiber cable on a transmission line tower.

[0002]

2. Description of the Related Art In recent years, transmission line towers have been equipped with communication systems that connect the tops of towers to the legs of towers in order to measure large currents flowing through transmission lines and various measurements under high voltage.
This communication system includes various sensors for measurement mounted on the top of a transmission line tower, a receiver mounted on a tower leg (at or near the ground surface), and signals transmitted between these various sensors and receivers. Optical fiber cable
When laying an optical fiber cable in a steel tower, the optical fiber cable has conventionally been subjected to external damage during and after the installation of the optical fiber cable, and an unreasonable burden on the optical fiber cable due to a support clamp for fixing the optical fiber cable to the steel tower. In order to prevent the optical fiber cable from being
It is housed in a plastic conduit that is a bull protection tube,
A method has been adopted in which this is laid so as to rise to the top of the steel tower along the tower portion of the power transmission line, and clamped at the tower top portion and the steel tower leg portion.

[0003]

According to this conventional method, it is possible to prevent the optical fiber cable from being damaged by an external force and being unduly burdened by a clamp during the laying process. However, the total weight of the optical fiber cable is reduced. As the length of the vertically installed optical fiber cable increases, excessive tensile force is applied to the clamp point at the top of the optical fiber cable, as it will concentrate at one point on the terminal side of the tower. It has been taken. Therefore, in the optical fiber cable laid by the conventional method, there is a risk that slip-down with respect to the plastic conduit and increase in transmission loss due to accumulation of strain in the core and clad of the optical fiber that is the optical signal transmission path may occur. was there.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a method of laying an optical fiber cable on a power transmission tower without fear of slipping off of the optical fiber cable or increase in transmission loss. is there.

[0005]

In order to achieve the above object, the present invention accommodates an optical fiber cable in a cable protection tube and raises it to the top of a steel tower along a transmission line tower leg. In a method of laying an optical fiber cable to a transmission line tower that is fixed to the transmission line tower, a plastic protection tube previously divided into two or more in an installation route of the optical fiber cable and an optical fiber cable A steel tower fixing cylinder having an insertion hole and having an elastic projection around the insertion hole, the elastic projection allowing the insertion of the optical fiber cable only from one side by bending elastic deformation, is used.
When the cable protection tube and the optical fiber cable are installed, the steel tower fixing cylinder is interposed between the adjacent cable protection tubes so that the optical fiber cable is fixedly supported on the steel tower.

[0006]

[Function] The optical fiber cable is equipped with a steel tower fixing cylinder.
It is supported and fixed to the tower by a laying route other than the top of the tower.
Therefore, the fixed supporting points of the optical fiber cable are not concentrated in one place.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

First, a plastic conduit tube (cable protection tube) 1 to be erected from a leg portion to a top portion of a power transmission line tower is divided into a plurality of pieces in advance. Next, as shown in FIG. 1, a plastic conduit tube 1 to be first laid on a steel tower is laid on the steel tower, and an optical fiber cable 2 is inserted therethrough. After the optical fiber cable 2 is inserted, the plastic conduit 1 is attached to the end on the laying side (the end on the pulling side) of FIG.
The steel tower fixing cylinder 3 having the structure as shown in FIG. 2 is inserted to integrate the steel tower fixing cylinder 3 and the optical fiber cable 2.
The steel tower fixing cylinder 3 is fixed to the steel tower by a steel tower side support clamp, and in particular, the steel tower fixing cylinder 3 according to the present invention has a plastic conduit tube 1 having an inner diameter and an outer dimension.
When the steel tower fixing cylinder 3 is inserted into the optical fiber cable 2 at the center portion of the inner side surface which is almost the same as the cable insertion hole, it is elastically bent and deformed by itself. It is provided with an intermediate support part 4 for enabling only the above.
The intermediate support portion 4 has a cable insertion hole 5 at its center, which has a diameter appropriately smaller than that of the optical fiber cable 2. And the upper truncated conical tube section is divided into at least two or more in the circumferential direction, and the upper truncated conical tube section is connected to the optical fiber cable. It is composed of a plurality of notches 6 that are independent of the bull 2 and are elastic projections 4a.

As described above, in the method of laying an optical fiber cable on a steel tower according to the present invention, a plastic conduit tube 1 which is divided into an appropriate number in advance and a steel tower fixing tube 3 of a number corresponding to the plastic conduit tube 1 are prepared. It is a method of alternately connecting the plastic conduit tube 1 and the steel tower fixing cylinder 3 in the laying direction of the optical fiber cable 2.
Moreover, since the number of fixed support points of the optical fiber cable 2 is easily increased by the elastic projections 4a of the steel tower fixing cylinders 3 as compared with the conventional method, the optical fiber cable 2 slips down due to its own weight, There is no accumulation of strain in the optical fiber core and cladding due to abnormal clamping. Therefore, the transmission performance of the optical fiber is maintained for a long time.

In FIG. 3, in order to improve the connection between the plastic conduit tube 1 and the steel tower fixing cylinder 3, the steel tower fixing cylinder 3 is gradually narrowed down, and both ends of the steel tower fixing cylinder 3 are The plastic conduit tube 1 is provided with connecting tube portions 7 and 8 which are fitted to the inner peripheral surface of the plastic conduit tube 1 in an inlay manner.

[0011]

As is clear from the above description, according to the present invention, the following excellent effects are exhibited.

(1) Since the number of fixed supporting points of the optical fiber cable can be easily increased, it is possible to prevent the optical fiber cable from slipping off and the transmission loss from decreasing.

(2) It is possible to improve work efficiency and simplify work.

[Brief description of drawings]

FIG. 1 is a cable protection tube, an optical fiber cable, and a method for laying an optical fiber cable on an electric power line of a tower according to the present invention.
It is sectional drawing which shows the relationship of the steel tower fixing cylinder.

FIG. 2 is a cross-sectional view of a steel tower fixing cylinder according to the present invention.

FIG. 3 is a sectional view of a steel tower fixing cylinder according to the present invention.

[Explanation of symbols]

 1 plastic conduit tube (cable protection tube) 2 optical fiber cable 3 tower fixing cylinder 4a elastic projection 5 cable insertion hole

Claims (1)

[Claims] 1. A transmission line tower in which an optical fiber cable is housed in a cable protection tube, which is erected to the top of the tower along a transmission line tower leg and fixed to the transmission line tower. In the optical fiber cable laying method, a plastic protective tube which is previously divided into two or more pieces in the laying route of the optical fiber cable and a fitting hole for the optical fiber cable are provided, and the plastic protection tube has its own fitting hole around the fitting hole. A steel tower fixing cylinder provided with an elastic projection that allows the optical fiber cable to be fitted only in one direction by bending elastic deformation, and is adjacent to each other when the cable protection tube and the optical fiber cable are laid. A method of laying an optical fiber cable to a transmission line tower, characterized in that the steel tower fixing cylinder is provided between the cable protection tubes so that the optical fiber cable is fixedly supported on the tower.