JPH0491611A - Cable laying method in buried pipe - Google Patents

Abstract

PURPOSE:To lay a cable easily and reliably in a buried pipe without damaging the buried pipe by securing wire supporting metals in manholes, pulling a protective pipe previously inserted with a wire and a cable into the buried pipe by means of a lead wire and then securing the wire to the supporting metals at the opposite ends thereof. CONSTITUTION:A lead wire 4 is stretched in a buried pipe 1 from an upstream manhole B to a downstream manhole A. Wire supporting metals 5 are then secured to the inner faces of the manholes A, B. A wire 6 is then tied to the trailing end of the lead wire 4. The lead wire 4 is then pulled up from the downstream manhole A thus pulling the wire 6, along with a protective pipe 17, into the buried pipe 1 between the manholes A and B. Leading end of the wire 6 is then secured to a metal 5A and the trailing end of the wire 6 is hoisted by a winch 13 thus imparting tension on the wife 6.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for laying a cable in a buried pipe, and in particular, a method for laying a cable in the upper part of the buried pipe along its axial direction. This relates to a method of laying cables in buried pipes.

[Conventional technology]

BACKGROUND ART In recent years, when laying communication cables or electric cables (hereinafter simply referred to as cables), a method of laying the cables inside existing underground pipes such as sewer pipes has been implemented in order to reduce installation costs.

As shown in Figures 9 and 10, one method of laying cables inside existing underground pipes is to manually lay cables in the case of large-diameter pipes, or by laying cables in the case of small-diameter pipes. There is a method of fixing the cable 2 along the upper inner surface of the buried pipe 1 with an anchor 3 using a robot.

[Problem to be solved by the invention]

However, the above method has the following problems.

■ Methods using laying robots lack reliability, and there is a risk of damaging the buried pipe by driving the anchor.

■ Manual methods are time consuming and, like the case with laying robots, there is a risk of damaging the buried pipe by driving the anchor.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for laying a cable in a buried pipe, which allows the cable to be laid reliably and in a short time, and which does not cause damage to the buried pipe.

[Means to solve the problem]

In this invention, a conductive wire is stretched from one manhole of a buried pipe to the other manhole, wire support fittings are then fixed in both said manholes, and then a protective pipe into which wires and cables have been inserted in advance is inserted into said manhole. The present invention is characterized in that a conducting wire is drawn into the buried pipe extending from the one manhole to the other manhole, and then both ends of the wire are fixed to the supporting metal fittings.

Next, an embodiment of the method for laying a cable in a buried pipe according to the present invention will be described with reference to the drawings.

1 to 3 are process diagrams showing one embodiment of the method of laying cables in a buried pipe according to the present invention, and FIGS.
The figure is a sectional view taken along the line A--A in FIG. 2.

As shown in FIGS. 1 to 5, the method of laying a cable in a buried pipe according to the present invention first involves laying a cable from an upstream manhole B to a downstream manhole A of a buried pipe 1, as shown in FIG. and then stretch the conductor 4.

To stretch the conductor 4, a float is attached to the conductor 4 and the float is allowed to flow through the underground pipe 1, for example, into the sewer, or,
Use the launcher.

Next, as shown in FIG. 2, wire support fittings 5 are fixed to the inner surfaces of both manholes A and B. Wire support fitting 5
fixes both ends of the wire 6, which will be described later, and
It applies tension to.

The wire support fitting 5 will be explained with reference to the drawings.

FIG. 6 is a cross-sectional view of a wire support fitting for carrying out the method of laying a cable in a buried pipe according to the present invention, and FIG.
FIG. 6 is a view taken from the direction B, and FIG. 8 is a view taken from the B direction of FIG. 4.

The wire support fitting 5 consists of a metal fitting 5A fixed in the downstream manhole A and a metal fitting 5B fixed in the upstream manhole B.

The metal fitting 5A includes a metal fitting body 7, a pulley 8 attached to the lower part of the metal fitting body 7, a nut 9 fixed to the tip of the wire 6, and between the nut 9 and the upper surface of the metal fitting body 7. It consists of an intervening spring 10 (expletive).

The purpose of the spring 10 is to buffer excessive tension applied to the wire 6.

The metal fitting 5B consists of a metal fitting body 1), a pulley 12 attached to the lower part of the metal fitting body 1), and a winch 13 that winds up the rear end of the wire 6 and applies tension to the wire 6. The winch 13 consists of a gear 15 for preventing reverse rotation, around which six wires are wound, and a winding drum 14 having claws 16 that engage the gear 15.

The drum 14 can be rotated by an I/endor (not shown).

According to the wire support fitting 5 configured in this way, the nut 9 is fixed to the tip of the wire 6, and the rear end of the wire 6 is wound up by the winch 13 via the pulleys 8 and 12, thereby applying tension to the wire 6. can be granted.

Next, as shown in FIG.
connect. The wire 6 is inserted into the protective tube 17. The wire 6 and cable 18 are inserted into the protective tube 17 in advance. Then, the conducting wire 4 is pulled up from the downstream manhole A, and the wire 6 is drawn together with the protective pipe 17 into the buried pipe 1 extending from manhole 8 to manhole B.

As shown in FIG. 4, the protection tube 17 is a circular resin tube,
Alternatively, as shown in FIG. 5, it may be a resin band.

Next, as shown in FIG. 3, the tip of the wire 6 is fixed to the metal fitting 5A as described above, and the rear end of the wire 6 is wound up by the winch 13 to apply tension to the wire 6. . Thereby, the cable 18 protected by the protection tube 17 can be reliably laid on the upper inner surface of the buried tube 1 along its axial direction.

If the installation of the cable 18 is to be further extended, the above-described operation may be repeated.

〔Effect of the invention〕

As explained above, according to the present invention, a useful effect is brought about in that a cable can be reliably and easily laid in a buried pipe without damaging the buried pipe.

[Brief explanation of drawings]

1 to 3 are process diagrams showing one embodiment of the method of laying cables in a buried pipe according to the present invention, and FIGS.
The figure is a sectional view taken along the line A-A in FIG. A direction view of
Fig. 8 is a view taken from direction B in Fig. 4, Fig. 9 is a cross-sectional view showing the state in which the cable is laid in a buried pipe by the conventional method, and Fig. 10 is a cross-sectional view taken along the line A-A in Fig. 9. It is a diagram. In the drawings: 1 - buried pipe, 2 - cable, 3 - anchor, 4 conduit, wire support fitting, fitting body, nut, fitting body, winch, gear protection tube, wire pulley, spring, pulley, drum, pawl, cable.

Claims (1)

[Claims] (1) A conductive wire is stretched from one manhole of the buried pipe to the other manhole, and then wire support fittings are fixed in both manholes, and then a protective tube into which wires and cables have been inserted in advance is connected to the conductive wire. A method of laying a cable in a buried pipe, characterized in that the wire is drawn into the buried pipe from the one manhole to the other manhole, and then both ends of the wire are fixed to the support fittings.