JPS6231314A - Installation of cable in tube and impeller used therefor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of laying a cable in a pipe and an impeller used in the method.

[Conventional technology]

In recent years, the use of optical communication has diversified into LAN, FA, LA, OA systems, etc., and accordingly, it is being considered to further streamline the installation of optical fiber lines. One such idea is to construct a rational optical communication network using existing wiring/piping networks such as gas pipes from the viewpoint of securing land, construction costs, and space. Among them, gas pipes
It appears to be suitable as a conduit for optical cables. Also,
When installing an optical cable into a relatively small-diameter pipe, such as a gas pipe, it is economical to use the windsock installation method, which creates a flow of air or other fluid within the pipe and inserts the cable along with the flow. Be efficient.

[Problem that the invention seeks to solve]

However, cable insertion poses some problems, especially in the case of gas pipes. One typical example is the protrusion inside the gas pipe that occurs at the joint of the gas pipe.

This is because when welding gas pipes, molten material builds up inside the pipes.
This is a so-called "flash", but if this happens, the cable jacket will hit the cable jacket when it is pulled in, preventing the cable from moving, damaging the cable jacket, and in extreme cases, damaging the optical fiber core. Sometimes.

In addition, there may be a step at the joint of the gas pipe, and experiments have confirmed that this step also causes similar troubles.

The above-mentioned disadvantages can be alleviated to some extent by changing the structure of the optical cable, the material of the outer sheath, and the selection conditions of mechanical properties.
This is because gas pipes have many curved parts and the distance between openings is long, ranging from several hundred meters to several kilometers.

It is impossible to avoid it completely.

This invention has been made in view of the above, and provides a method and direction for easily inserting optical cables and other cables into existing pipes such as gas pipes that have many complicated curves and without causing damage. It provides an impeller.

[Means for solving problems]

As shown in FIG. 1, the method of the present invention, which solves the above-mentioned problems, generates a flow 2 of fluid, for example, compressed air, inside a tube 1, and carries it along with the flow 2 to blow air from an opening 1a at one end of the tube 1 to the other side. In the cable windsock installation method in which the cable 3 is inserted into the pipe toward the end opening 1b, it is preferable to fix a stopper 4 to the tip of the cable 3 to stop an impeller, which will be described later, and to further install a stopper 4 on the source side of the fluid flow. opening 1a of a pipe
Therefore, the maximum diameter part of the blade, which is rotatable with respect to the cable, has some sliding resistance in the cable axial direction, and has enough strength to support the cable, is slightly smaller than the inner diameter of the pipe 1. It is characterized in that the shuttlecock-like impeller 5 is successively passed through the cable and sent into the pipe.

In addition, the impeller 5 used in this method is shown in Figures 2 and 3.
As shown in the figure, a cylindrical base 6 whose inner diameter is slightly larger than the outer diameter of the cable, and a mycelium 7 that can support the cable with one end fixed to the base as a base point are extended outward in a trumpet shape. The mycelium 7 is expanded and divided into a plurality of parts in the circumferential direction on the way from at least one end to the other, and each divided part 7a is twisted in one direction, and the diameter of the maximum diameter part is the inner diameter of the tube into which the cable is inserted. It consists of a smaller blade 8 and a damper 9 attached to the base 6 with contact surfaces 9a to the cable provided at three or more points in the circumferential direction arranged on the circumference of a circle slightly smaller than the cable diameter. be done.

When the impeller 5 is successively passed through the cable and fed into the pipe, it generates rotational force and thrust due to the fluid pressure received at the rear, and as shown in FIG. 4, moves toward the tip of the cable while rotating on the cable 3. During the movement, for example, as shown by the chain line, the cable 3 caught on the Paris 10 etc. inside the pipe is lifted up from the inner surface of the pipe as shown by the solid line,
Separate from Paris etc. Therefore, according to the method of the present invention in which the impeller is sequentially passed through, the cable can be smoothly passed through a pipe or a gas pipe with many curves.

In addition, since the damper 9 is pressed against the cable, the impeller 5 has a slight sliding resistance against the cable, and the impeller 5 moves forward while dragging the cable due to the wayul braking effect, which prevents it from moving quickly even when it receives fluid pressure. The retraction speed will also be faster.

Please note that the impeller must be fed periodically.

Uniform traction force can be applied to multiple locations on the insertion cable at regular intervals, and smoother insertion can be expected; however, if the cable gets caught in the pipe, the feeding speed will decrease, which may cause abnormalities. Since it can be confirmed, it may be sent after confirming the abnormal situation.

Further, although the stopper 4 is not essential, if it is provided, the impeller will stop at the end of the cable, thereby increasing the traction effect by the impeller.

Further, the damper 9 of the impeller may be of any type as long as it can provide a movement guide effect and a braking effect of the impeller, and its shape etc. are not particularly limited. For example, the damper shown in the figure uses wheels made of rubber or the like with a spindle supported by a base, but there are also balls that move on cables, protrusions with spherical tips, etc.
Alternatively, it may be an elastic body that contacts the cable intermittently or continuously in the circumferential direction. The blades 8 of the impeller may also be formed by arranging a plurality of independent mycelium on the same circle. In addition, the flow of fluid in the pipe is controlled by arranging a compressor such as a compressor on the source side, and introducing the compressed fluid into the pipe from the opening 1a of the pipe 1 with the opening 1b open.
Alternatively, it may be generated by opening the opening 1a and evacuating the opening 1b with a vacuum pump, or by a combination of the two methods. The method of feeding pressurized fluid requires introducing the fluid, cable, and impeller through the opening 1a, which complicates the insertion mechanism for the cable and impeller, but the vacuum method does not have this problem. .

〔effect〕

As described above, according to the method of the present invention, even if the cable gets caught inside the pipe, the impeller that feeds the cable into the pipe is pushed by the fluid and lifts the cable toward the center of the pipe. Since the cable is unhooked, the cable can be easily and smoothly inserted into the windsock, and damage to the cable is also prevented.

In addition, since one impeller pulls the cable while moving, the speed at which the cable is pulled in is increased, and in the case of existing gas pipes, etc., the time during which the supply of gas, etc., is stopped is shortened.

Furthermore, compared to the conventional windsock construction method, only an extra impeller is required, so there is no need to worry about increased construction costs.

On the other hand, since the impeller of this invention lifts the cable by moving while rotating on the cable, it not only removes the tension on the cable, but also has the effect of preventing the cable from getting caught and increasing the moving force of the cable. There is.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the method of this invention, FIGS. 2 and 3 are perspective views and rear views showing an example of the impeller of this invention,
FIG. 4 is a sectional view showing the function of the impeller. 1...Pipe, 3...Cable, 4...Stopper, 5
... impeller, 6... cylindrical substrate, 7... mycelium, 8.
...Blade, 9...Damper

Claims (4)

[Claims] (1) In the cable windsock installation method, in which a fluid flow is generated in the pipe and the cable is inserted into the pipe from one end of the pipe toward the other end along with the flow, the cable is placed on the source side of the fluid flow. From the opening at one end of the tube, the maximum diameter of the blade, which is rotatable relative to the cable, has some sliding resistance in the cable axial direction, and has enough strength to support the cable, is larger than the inner diameter of the tube. A method for laying a cable in a pipe, which is characterized by passing slightly smaller shuttlecock-like impellers through the cable and feeding them into the pipe. (2) The method for laying a cable in a pipe according to claim (1), characterized in that an impeller stopper is attached to the tip of the cable. (3) A cylindrical base with an inner diameter slightly larger than the outer diameter of the cable, and one end fixed to the base as a base point, and the other end of the blade strong enough to support the cable is extended outward in a floppy shape. At the same time, the blade is divided into multiple parts in the circumferential direction on the way from at least one end to the other end, and each divided part is twisted in one direction so that the maximum diameter part is slightly larger than the inner diameter of the pipe into which the cable is inserted. Cable installation in a pipe consisting of small blades and a damper attached to the base with the contact surface to the cable provided at three or more points in the circumferential direction on the circumference of a circle slightly smaller than the cable diameter. impeller. (4) The impeller according to claim (3), wherein the damper is a wheel equipped with a support shaft.