JPS61199409A - Installation of cd cable - 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] (Industrial Application Field) This invention relates to a method for laying a CD cable (ducted cable), and more specifically, a method for laying a CD cable in a structure such as a tunnel or a conduit. It is related to.

(Prior Art) Various methods have been developed to install ordinary power cables or communication cables in structures such as tunnels and conduits. As shown in FIG. 8, a typical method for laying cables is to hold the cable 102 pulled out from the delivery section (delivery drum) 2 under pressure by a caterpillar-type pulling device 101 (within the manhole). Draw to 11,
This is a method in which the cable 102 that has reached a structure 6 such as a tunnel or conduit below is laid while the cable 8 inside the structure 6 is taken over by the take-up winch 4.

This method can be used to install ordinary cables, whether electric cables or communication cables, without any problems, but it cannot be applied to combined duct cables (abbreviated to CD cables) as described below. It is something.

(Problems to be Solved by the Invention) As shown in FIG. 2, the CD cable has an outer coating (
This is a special cable with a structure in which a protective tube 11 is provided with a considerable clearance outside a cable core 12 without an external sheath.

Therefore, if such a cable is laid by the conventional method explained with reference to FIG. It only holds the internal cable or cable core 12.
Since there is no support for the protective tube 11, the cable or cable core 12 slides down inside the protective tube 11 due to its own weight, reaches the bottom of a structure 8 such as a tunnel, and accumulates. The CD cable, which is susceptible to buckling failure, is wound at least once around the capstan wheel of a capstan device located below its delivery portion, and then guided to a lower laying position.

(Function) The CD cable fed out from the feeding section (7) is wound around the capstan wheel of the capstan device at least once and bent into a loop shape before being guided downward, so that the internal The cable or cable core comes into contact with the inner wall surface of the outer protective tube over a considerable area, and therefore a large frictional resistance is generated between the cable or cable core and the inner wall surface of the protective tube.

(Example) An embodiment of the invention will be described with reference to FIG.

In the method of this invention, the capstan device 3 is installed on the same horizontal plane as the position where the delivery portion 2 of the CD cable 1 is provided. For example, when the delivery section 2 is installed on the ground, the capstan device 3 is also installed at a location on the ground close to the capstan device 3.

After the 0C11 cable 1 is wrapped around the capstan wheel of the capstan device i3 1.2 times, it is lowered into a manhole 7 and guided into a structure 6 such as a tunnel or a conduit. In this structure B, as in the conventional method,
Guide roller group 5 arranged in series along the cable installation line
The CD cable 1 is laid while the winding winch 4 takes over the messenger wire 8 placed on top and connected to the tip of the CD cable 1.

When the CD cable 1 is wrapped once around the capstan wheel of the capstan device 3, the CD cable 1
The inside is in the state shown in FIG.

That is, due to its own weight 1, the cable or cable core 12 inside the CD cable 1 comes into contact with the inner wall surface of the protection tube 11 at first between 29 and then between R8 and the inner wall surface of the protection tube 11.
Contact the inner wall surface on the opposite side of 1. Thus, it starts to come into contact with the inner wall surface on the first side again from point T and comes into contact over the arc TPQ. As can be seen from the diagram, the internal cable or cable core can be wrapped around the protective tube over an angular range of approximately 250 degrees or more with one winding.
1, and as a result, sufficient frictional resistance is ensured to prevent relative positional displacement in the longitudinal direction between the protective tube 11 and the cable or cable core 12, thereby effectively preventing the cable or cable core 12 from sliding down. This is something that can be prevented.

(Effects of the Invention) According to the present invention, before the CD cable fed out from the feeding section is guided downward, the CD cable is wound around the capstan wheel of the capstan device at least once. , the CD cable is bent over at least 860 degrees, 7 so that the inner cable or cable core of the CD cable contacts the inner wall surface of the outer protection tube over a considerable angle;
Therefore, the CD cable can be laid while preventing the cable or cable core from slipping due to the large frictional resistance generated between the cable or cable core and the inner wall surface of the protection tube, which may cause buckling damage to the cable or cable core. The effect of eliminating this can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of a situation in which the method of the present invention is implemented, Fig. 2 is a sectional view showing an example of a C'D cable, and Fig. 8 is a side sectional view illustrating a conventional installation method. , FIG. 4 is a side view for explaining the state in which the CD cable is wound around the capstan wheel.

Claims (1)

[Claims] In a method of laying a CD cable (1) in a structure (6) such as a tunnel or a conduit located below its delivery part (2), the CD cable (1) is installed in a structure (6) located below the delivery part (2). ) A method for laying a CD cable, which comprises wrapping the cable at least once around the capstan wheel of a capstan device (3) disposed on substantially the same horizontal plane as the cable, and then guiding the cable toward a lower laying position.