JPH0373205B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for pulling out a cable installed in a conduit.

[Conventional technology]

Conventionally, when pulling out a cable installed in a conduit, the method used was to use a winch car, etc., attach a pulling eye, etc. to the tip of the cable, and pull the cable above ground through a hook in the manhole. It had been.

An example of such a conventional construction method is shown in FIG. 4 and briefly explained. In Fig. 4, 1 is a pipe, 2 is a cable laid in the pipe 1, 3 is a manhole, 4 is a hook installed on the wall inside the manhole, and 5 is a cable that is hung on the hook. In addition, a wire is tied to a wire grip 6 that grips the cable 2, 7 is a guide pipe that leads the cable 2, and 8 is a wire that connects the wire 5 to a wire grip 6 that holds the cable 2.
The capstan for winding ~4 times, 9 a winch mounted on the car CA, 10 and 11 the shutter and caterpillar mounted on the car CB, respectively, and 12 the winding drum mounted on the car CC.

Here, the cable 2 to be pulled out is grasped by the wire grip 6, and the wire 5 tied to the wire grip 6 is wound around the winch 9 via the hook 4 and the capstan 8. It is wound onto a winding drum 12 via a caterpillar 11.

[Problem that the invention seeks to solve]

With the above-mentioned conventional construction method, (1) there is a risk that the wire etc. may damage equipment already in the manhole, (2) conversely, the equipment may become an obstacle and the wire cannot be stretched. (3) The strength of the hook inside the manhole is insufficient for the pulling force, (4) the hook is not installed, and (5) the pipe opening and the hook are not in a straight line, etc. There was a problem that it was difficult to apply the above construction method.

In view of the problems of the prior art described above, the present invention has been made to
The object is to provide a construction method of this type that allows work to be carried out in a manhole without taking up much space, and which also makes it possible to pull out cables that have a high resistance to pulling out.

[Means for solving problems]

The cable pulling method provided by the present invention involves attaching a bottom adapter to the pipe mouth or wall surface in a manhole, connecting two or more sets of hydraulic cylinders with their outer cylinders to the bottom adapter, and protruding the cable from the pipe mouth. Arranged protrudingly in parallel along the direction,
The protruding ends of each rod of the hydraulic cylinders are connected together with an upper adapter, and the conductor exposed at the cable part protruding from the conduit opening is extended to the front of the upper adapter so that a wire clip is directly gripped there. The above hydraulic cylinders are driven all at once to push the upper adapter forward in conjunction with the wire clip and pull out the cable.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the cable pulling method according to the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, 21 is the side wall of the manhole, 22 is the end of the waterproof cast iron pipe forming the pipe entrance, and 23 is the bottom adapter, which is a cable (see 1 in Figure 4) installed in the pipe. (See 2 in Figure 4) For example, when pulling out a single-core cable, the end 22 of the waterproof cast iron pipe
It can be attached to the manhole side wall 21 with bolts (not shown), but if there is no waterproof cast iron pipe, it can be fixed to the manhole side wall 21 with anchors.

Three sets of hydraulic cylinders 2 are installed in the bottom adapter 23.
The outer cylinders 4, 25, and 26 are connected together. These hydraulic cylinders 24, 25, and 26 are arranged in parallel with each other and protrude from the conduit opening along the direction of cable protrusion, and the protruding ends of their rods 27 are collectively connected by an upper adapter 28.

One end side of a hydraulic hose 30 is connected to each hydraulic cylinder 24, 25, 26 through piping ports 29 provided at the upper and lower parts, and the other end side of the hydraulic hose is connected to a hydraulic pump 32 via a three-way branch 31. Therefore, a specified hydraulic piping system is attached. In one three-way branch 31, gauges 33 such as a hydraulic pressure gauge and a tension gauge are arranged in communication.

In the process of assembling as described above, the cable 2 protruding from the conduit opening is passed through the cable passage holes of the bottom adapter 23 and the top adapter 28 and extended to the front of the top adapter, and the sheath and insulation are stripped off at that part. The wire clip 34 is directly gripped to the exposed conductor 2a.

When the assembly is completed as described above, the work begins. First, the rod 27 is moved back and the upper adapter 28 is positioned on the bottom side as shown by the broken line, and the wire clip 34
The conductor shall be grasped in a position linked to the front surface of the upper adapter in such a position. After that, while monitoring the gauge 33, the oil pressure is gradually increased to push the rod 27 forward, and the pushing force of the rod 27 moves the upper adapter 28 forward, pressing the wire clip 34 while pushing the cable 2
I'm going to pull it out.

When the rod 27 has reached its maximum extrusion length, reduce the hydraulic pressure to return the rod to its original retracted position, expose the conductor in the forwardly protruding cable section, and connect the wire clip to the upper adapter as before. position, and repeat the above operations.

Note that the number of hydraulic cylinders is not limited to three, but two or more sets can provide sufficient hydraulic extrusion force.

Further, in the above-described embodiment, the case where three cables are pulled out at once is shown, and accordingly, three cable passage holes are formed in the bottom adapter and the top adapter. Wire clips that can accommodate three cables are also used. However, if the number of cables to be pulled out is other than that, it is sufficient to replace the adapter with an adapter that has a corresponding number of cable passage holes. Of course, the same applies to wire clips.

Furthermore, if there are two sets of hydraulic cylinders, the adapter can be devised to have a shape that does not require a cable passage hole.

[Operations and Effects of the Invention] As explained above, according to the cable pulling method of the present invention, the cable is pulled out by hydraulic control of the hydraulic cylinder, so the series of operations can be carried out safely. Of course, the following actions and effects can be achieved.

(1) A hydraulic cylinder, which is the main body of the device, is arranged to protrude from the conduit opening in the direction in which the cable is projected, and its rod tip is linked to a wire clip that grips the exposed conductor of the cable via an upper adapter. This allows most of the mechanisms to be placed close to the cable.
You can work comfortably in the manhole without taking up much space.

(2) The upper adapter receives the extrusion force of the rods of two or more parallel hydraulic cylinders at the same time and pushes the wire clip, which is gripped directly onto the cable conductor to prevent it from slipping. Hydraulic extrusion force can be reliably transmitted to the conductor of the cable without loss, and therefore a cable that has high pullout resistance and significant pullout tension can be easily pulled out.

[Brief explanation of drawings]

1 and 2 are a side view and a front view showing an embodiment of the cable pulling method according to the present invention, and FIG. 3 is a schematic diagram showing a conventional cable drawing method. In the code, 1 is a conduit, 2 is a cable, 2a
3 is the exposed part of the conductor, 3 is the manhole, 21 is the side wall of the manhole, 22 is the end of the waterproof cast iron pipe which becomes the pipe opening, 23
is a bottom adapter, 24, 25, 26 are hydraulic cylinders (outer cylinders), 27 is its rod, 28 is an upper adapter, 29 is a piping port, 30 is a hydraulic hose, 31 is a three-way branch, 32 is a hydraulic pump, 33 is an instrument ,
34 is a wire clip.

Claims (1)

[Claims] 1. Attach a bottom adapter to the conduit opening or wall surface in the manhole, connect two or more sets of hydraulic cylinders with their outer cylinders to the bottom adapter, and arrange them to protrude in parallel from the conduit opening along the direction in which the cable protrudes. ,
The protruding ends of each rod of the hydraulic cylinders are connected together with an upper adapter, and the conductor exposed at the cable part protruding from the conduit opening is extended to the front of the upper adapter so that a wire clip is directly gripped there. A cable pulling method characterized in that the above hydraulic cylinders are driven all at once to push the upper adapter forward while linking it to the wire clip to pull out the cable.