JPH063965B2 - Cable laying method inside pipe and impeller used for the method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for laying a cable in a pipe and an impeller used for the method.

[Conventional technology]

In recent years, the use of optical communication has been diversified such as LAN, FA, LA, and OA systems, and accordingly, it is considered to further rationalize the installation of optical fiber lines. From the viewpoint of securing land, construction cost, and space, one of them is to construct a rational optical communication network using existing wiring / pipe networks such as gas pipes. Above all, the gas pipe is considered to be suitable as a lead-in conduit for the optical cable. In addition, when an optical cable is drawn into a tube with a relatively small diameter, such as a gas tube, it is economical to use a blowing construction method in which a flow of fluid such as air is generated in the tube and the cable is inserted on the flow. Moreover, it is efficient.

[Problems to be solved by the invention]

However, especially in the case of gas pipes, some problems occur with the insertion of the cable. One of the typical ones is an intra-tube projection formed at the joint of gas pipes. This is because the molten material rises in the pipe during welding of the gas pipe and pops out as a so-called burr.If this occurs, the cable sheath will be hit when the optical cable is pulled in, the movement of the cable will be blocked, and the cable sheath will be damaged. Or, in extreme cases, the optical fiber core may be damaged.

Further, it is confirmed by experiments that a step may occur at the joint of the gas pipe, and this step causes the same trouble.

The above-mentioned inconvenience can be solved to some extent by changing the selection conditions of the structure of the optical cable, the material of the outer cover, and the mechanical characteristics.
Since the gas pipe has many bent portions and the distance between the openings is as long as several hundred m to several Km, it is impossible to avoid it completely.

The present invention has been made in view of the above, and a method for easily inserting a cable including an optical cable into an existing pipe such as a gas pipe having many complicated bends without damaging it and a blade used in that direction. It provides a car.

[Means for solving problems]

As shown in FIG. 1, the method of the present invention, which has solved the above-mentioned problems, causes a flow 2 of a fluid, for example, compressed air, to be generated inside a pipe 1, and the flow 2 is placed on the flow to cause the flow from the one end opening 1a In the cable winds installation method of inserting the cable 3 into the pipe toward the end opening 1b, preferably, a stopper 4 for stopping an impeller described later is fixed to the tip of the cable 3 and further, on the source side of the fluid flow. One tube opening 1
From a, the shuttle is rotatable with respect to the cable, has a slight sliding resistance in the cable axial direction, and has the maximum diameter portion of the blade with sufficient strength to support the cable, which is slightly smaller than the inner diameter of the pipe 1. It is characterized in that the cock-shaped impeller 5 is successively fed into the pipe through a cable.

Further, the impeller 5 used in the method is shown in FIGS.
As shown in the figure, the tubular base 6 having an inner diameter slightly larger than the outer diameter of the cable, and the other end of the vane 7 capable of supporting the cable with one end fixed to the base serving as a base is outwardly shaped like a trumpet. A pipe into which the diameter D of the maximum diameter portion is obtained by dividing the blade 7 into a plurality of portions in the circumferential direction on the way from at least one end to the other end and twisting each divided portion 7a in one direction. A blade 8 that is slightly smaller than the inner diameter of, and a damper 9 that is attached to the base body 6 by arranging three or more contact surfaces 9a for contacting the cable provided in the circumferential direction on the circumference of a circle that is slightly smaller than the cable diameter. Composed of.

When the impeller 5 is successively passed through the cable and fed into the pipe, a rotational force and a thrust force are generated by the fluid pressure received backward, and as shown in FIG. 4, the impeller 5 moves on the cable tip side while rotating on the cable 3. Then, during the movement, for example, as shown by a chain line, the cable 3 hooked on the burr 10 in the pipe is lifted from the inner surface of the pipe as shown by a solid line,
Separate from burrs, etc. Therefore, according to the method of the present invention in which the impeller is successively passed, it is possible to smoothly pass the cable through the gas pipe or the like having many burrs and bends.

Further, since the damper 9 is pressed against the cable, the impeller 5 has some sliding resistance with respect to the cable and moves forward while dragging the cable due to the so-called brake effect that does not move quickly even when receiving fluid pressure, so that The retraction speed will be faster.

In addition, if the impeller is fed periodically, it is possible to apply a uniform traction force to multiple points of the insertion cable at regular intervals, and smoother insertion can be expected, but the cable can be inserted into the pipe. If it is caught, the feeding speed is lowered, and the abnormality can be confirmed by it. Therefore, the feeding may be performed after confirming the abnormal situation.

Further, although the stopper 4 is not essential, the presence of the stopper 4 stops the impeller at the cable end, so that the impeller enhances the pulling effect.

Further, the damper 9 of the impeller is not particularly limited in its shape and the like as long as it can obtain the movement guide effect and the braking effect of the impeller. For example, although a wheel made of rubber or the like having a support shaft supported by a base is used as the damper shown in the figure, a spherical body rolling on the cable, a projection having a spherical tip, or intermittently in the circumferential direction or It may be an elastic body or the like that continuously contacts the cable. The vane 8 of the impeller may also have a plurality of independent vanes arranged on the same circle. In addition, for the flow of the fluid in the pipe, a compressor such as a compressor is arranged on the source side, and the fluid compressed by the compressor is introduced into the pipe from the opening 1a of the pipe 1 with the opening 1b opened, or the opening. It may be generated by any of a method of opening 1a and vacuuming from the opening 1b with a vacuum pump, or a method of combining both. In the method of feeding the pressurized fluid, it is necessary to introduce the fluid, the cable, and the impeller from the opening 1a, so that the insertion mechanism of the cable and the impeller becomes complicated, but the vacuuming method does not have that concern. .

〔effect〕

As described above, according to the method of the present invention, even if the cable is caught in the tube, the cable is lifted to the center side of the tube when the impeller passing through the cable and sending into the tube is pushed by the fluid and passes through. Since the hook is removed by pulling the cable, it is easy and smooth to insert the cable as a windsock, and damage to the cable is prevented.

In addition, since the cable is pulled while the impeller is moving, the cable drawing speed is increased, and in the existing gas pipe or the like, the supply stop time of gas or the like is short.

Further, as compared with the conventional windsock construction method, it is only necessary to have an extra impeller, so there is no fear of increasing the construction cost.

On the other hand, since the impeller of the present invention moves while rotating on the cable to lift the cable, it has an effect of not only pulling the cable but also an effect of preventing the cable from catching and an effect of increasing the moving force of the cable. .

[Brief description of drawings]

FIG. 1 is a schematic view showing a method of the present invention, FIGS. 2 and 3 are perspective views and rear views showing an example of an impeller of the present invention,
FIG. 4 is a sectional view showing the operation of the impeller. 1 ... Tube, 3 ... Cable, 4 ... Stopper, 5 ... Impeller, 6
… Cylindrical substrate, 7… Wings, 8… Wings, 9… Dampers

Claims (4)

[Claims] 1. A source flow of a fluid flow in a cable windsock laying method in which a fluid flow is generated in the pipe and the cable is inserted into the pipe from the one end opening portion to the other end opening portion on the flow. From the one end opening of the pipe located on the side, the maximum diameter of the blade, which is rotatable with respect to the cable, has some sliding resistance in the cable axial direction, and is strong enough to support the cable. A method of laying a cable inside a pipe, in which a shuttlecock-shaped impeller, which is slightly smaller than the above, is successively passed through the cable and fed into the pipe. 2. An impeller stopper is attached to the tip of the cable.
The method of laying the cable inside the pipe as described in (1). 3. A tubular base having an inner diameter slightly larger than the outer diameter of the cable, and the other end of the vane having a strength capable of supporting the cable with one end fixed to the base serving as a base, and the outer end having a trumpet shape. Toward the other end, and at least halfway from one end to the other end, divide the blade into a plurality of parts in the circumferential direction and twist each direction in one direction so that the maximum diameter part is greater than the inner diameter of the pipe into which the cable is inserted. Haze: A cable consisting of small blades and a damper mounted on the base body with the contact surfaces for 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. Impeller for laying in pipes. 4. The impeller according to claim 3, wherein the damper is a wheel having a support shaft.