JP2526209B2 - Optical fiber composite overhead ground wire manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing an optical fiber composite overhead ground wire, and more particularly to a method for twisting an aluminum-covered steel wire for an overhead ground wire.

(Prior Art) In recent years, an optical fiber composite overhead ground wire in which an optical fiber is passed through the overhead ground wire has been developed.

Such an optical fiber composite overhead ground wire has a structure as shown in FIG. 2, for example. That is, a fan-shaped steel wire 5 (hereinafter referred to as an aluminum-covered steel wire) having an aluminum coating 4 applied around an aluminum pipe 3 in which an optical fiber 1 is housed together with a spacer 2 is twisted in a predetermined number, for example, six. It is configured.

As a known method for twisting the aluminum-covered steel wire, there is a method in which the aluminum-covered steel wire is once pretwisted and then twisted in a separate step. To pre-twist aluminum-covered steel wire, a rigid type twisting machine or a dedicated machine with the same principle (pre-twister) is usually used.

(Problems to be Solved by the Invention) By the way, when pre-twisting an aluminum-covered steel wire, the repulsive force of the wire accumulates, which is a problem in handling.
Also, because the lines tend to become loose due to the repulsive force and the pitch tends to become large, the twisting pitch is set from the pitch after being loosened, but this twisting bitch is 15 to 20% more than the pre-twisted bitch before it was loosened. There is also a problem that it is difficult to control because the twisting rate must be increased because it becomes large.

In order to solve this problem, it is conceivable to perform pretwisting, then untwist in another step (including double threading by the same machine) to remove the repulsive force, and then twist the wires. Since it is a process, it is inefficient, and unevenness in pitch may occur, which may cause quality deterioration, which is not preferable.

The present invention has been made to solve such a problem, and the repulsive force of the pre-twisted aluminum-covered steel wire is removed during the pre-twisting process to facilitate the handling and twisting of the optical fibers. It is an object to provide a method for manufacturing an overhead ground wire.

[Structure of the Invention] (Means and Actions for Solving Problems) The present invention removes the repulsive force by pretwisting an aluminum-covered steel wire in an optical fiber composite overhead ground wire and then untwisting it during winding. To do. In this way, since the pre-twisted aluminum-covered steel wire having no repulsive force can be obtained because it is untwisted during winding, handling and twisting are easy.

(Example) Next, a method of pretwisting an aluminum-covered steel wire, which is a characteristic part of the present invention, will be described with reference to FIG.

Aluminum covered steel wire 7 stored in cage 6 as shown
Is twisted by rotating the 3-point preformer 8 in the direction of the arrow, and in that state, the cap 9a and the take-up capstan 10
It is wound by the winder 11 through the base 9b and the spinneret 9b. At the time of this winding, the winding drum is rotated in the twisting direction, that is, in the same direction as the rotation direction of the three-point preformer to untwist it. It is designed to prevent the lines from falling apart. The rotation amount of the winding drum is controlled by the speed reducer 12 and the continuously variable transmission 13, and the value thereof, that is, the untwisting pitch is calculated based on the following equation, and can be easily obtained by the pitch before and after the dislocation.

In the figure, reference numeral 14 is a winding motor, and reference numeral 15 is a line shaft which serves as a power for winding rotation.

The aluminum-covered steel wire pre-twisted in this manner had the looseness removed and was easy to handle and twist.

[Effects of the Invention] As described above, according to the method of the present invention, the final pre-twist pitch is obtained by the one-step pre-twisting work, and the looseness of the wires is removed. It is easy to obtain an overhead ground wire with stable quality. Further, there is an advantage that the manufacturing cost is low.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining a pretwisting process of an aluminum-covered steel wire which is a characteristic part of the method of the present invention, and FIG. 2 is a cross-sectional view of an optical fiber composite overhead ground wire. 1 ... Optical fiber 2 ... Spacer 3 ... Aluminum pipe 4 ... Aluminum coating 5 ... Steel wire 6 ... Case 7 ... Aluminum-covered steel wire 8 ... Preformer 9a, 9b ... Base 10 ... Take-up capstan 11 …… Winding machine 12 …… Reducer 13 …… Stepless transmission 14 …… Winding motor

Claims (1)

(57) [Claims] 1. In manufacturing an optical fiber composite overhead ground wire by twisting a predetermined number of aluminum-covered steel wires around an aluminum pipe having an optical fiber stored therein, the aluminum-covered steel wire is first pre-twisted. A method for manufacturing an optical fiber composite overhead ground wire, which comprises untwisting at the time of winding to remove repulsive force, and then twisting a predetermined number of twists.