JPH05126280A - Method for laying corrugated flexible pipe - Google Patents

Abstract

PURPOSE:To easily lead a long scale corrugated flexible pipe into an underground hole with no elongation deformation. CONSTITUTION:A clamp 2 having grooves 8 in both side parts is mounted to provide a space in the lengthwise direction of a corrugated flexible pipe 1, and a pair of towing wires 9 having protrusions 10 of interval matched with this space are respectively inserted into the grooves 8. The protrusions 10 are engaged with rear ends in both the side parts of the clamp 2 by these towing wires 9, and the clamp 2 is towed so as to lead the pipe 1 into an underground hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying a corrugated flexible pipe.

[0002]

2. Description of the Related Art Recently, when laying an underground cable, a corrugated flexible pipe 1 made of polyethylene, for example, as shown in FIG. 8 is buried in the ground in advance and the cable is inserted therein. The construction method is widely used.

However, when the corrugated flexible pipe 1 itself is laid, if a too large tension T is applied, the pipe is stretched and deformed in the axial direction as indicated by reference numeral 1a in FIG. When the wave height decreases and the radial drag decreases, the pipe itself receives the compressive force P (b) in the same figure.
There is a possibility of being crushed as indicated by reference numeral 1b. Therefore, in laying a corrugated flexible pipe, a method of digging up the surface of the ground and inserting the pipe into the ground to backfill is generally adopted.

[0004]

However, in recent urban areas, there are many problems such as the need to restrict the traffic to dig up the surface of the earth, and therefore the shield construction method for making a hole in the ground is changing. In this case, due to the above-mentioned problems, the drawing length is significantly limited, for example, the diameter is 100 m.
In the case of a polyethylene pipe of m, the length is about 25 cm, and when long laying is required, it is necessary to take measures such as providing a handhole on the surface of the ground at every interval, and there are many problems in terms of efficiency and cost.

Therefore, an object of the present invention is to solve the above problems and provide a method for laying a corrugated flexible pipe which can be easily drawn into an underground hole without extending and deforming a long corrugated flexible pipe. To do.

[0006]

In order to achieve the above object, the present invention is to mount clamps having grooves on both sides at intervals in the lengthwise direction of a corrugated flexible pipe and to project at intervals corresponding to the intervals. A pair of pulling wires each having the above are inserted into the groove, and the pulling wires engage the projections with the rear ends of both sides of the clamp to pull the clamp, and the pipe is drawn into the underground hole.

[0007]

When the pulling wire is pulled, the projections on the pulling wire engage with the rear ends of both sides of the clamp, and the corrugated flexible pipe is pulled by the clamps attached at intervals in the lengthwise direction. As a result, it can be easily inserted into the underground hole without being stretched and deformed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a corrugated flexible pipe (hereinafter also simply referred to as a pipe) made of polyethylene or the like used for laying an underground cable. The pipe 1 has a lengthwise direction as shown in FIG. A clamp 2 is mounted at a distance. This clamp 2 has a pipe holder 3 at the center.
Is composed of halved clamp pieces 2a and 2b having support wings 4 and 4 on both sides, and both clamp pieces 2a and 2b are fastened by bolts 5 and nuts 6 at the base of the support wings 4. The pipe 1 is held in the pipe holding portion 3 via a spacer 7 formed of a split mold or a tape winding that fits the corrugated surface of the pipe 1.

A groove 8 is formed on the supporting blade 4 so that the outer surface of the support blade 4 communicates with the outside in the front-rear direction. A pulling wire (hereinafter also simply referred to as a wire) 9 is inserted into the groove 8. Protrusions 10 are attached to the pair of wires 9, 9 for pulling both sides of the clamp 2 along the length direction at an interval m corresponding to the attachment interval s of the clamp 2, and the protrusions 10 pull the wire 9. The support wing 4 of each clamp 2
It comes to engage with the rear end of each of these to push these clamps 2, respectively. Therefore, in order to prevent tension from acting on the pipe 1, it is desirable that the mounting interval m of the protrusions be slightly smaller than the mounting interval s of the clamp 2. The clamp 2
It is appropriate that the mounting interval s is such that undue tension is not applied to the pipe itself due to friction with the underground hole wall, for example, 5 to 20 cm.

As shown in FIGS. 4 (a) and 4 (b), the protrusion 10 has an outer diameter D1 larger than the outer diameter d of the wire 9, and the center is prismatic (may be cylindrical) and both ends are rounded. An attachment groove 11 for passing the wire 9 is formed on the axis of the protrusion 10, which is formed in the shape of a spindle having a conical shape with an arrow. The wire 9 and the groove lid 12 are inserted into the attachment groove 11. It is integrated by compressing it.

As shown in FIG. 3, the width of the groove 8 of the supporting blade 4 is tapered so as to gradually decrease from the front end width d1 toward the rear end width d2. By setting d2 <d <d1, the wire 9 is formed. It is easy to come off from the front end side, but hard to come off from the rear end side. Further, the outer diameter D1 of the protrusion 10 is provided on the rear end side of the groove 8.
An engagement hole 13 is formed which has an inner diameter D2 slightly larger than that of the projection 10 and which engages with the front end of the projection 10 (see FIG. 2).

Further, the front end portion of the supporting blade 4 is shown in FIG.
As shown in (b) to (b), when the wire 9 is pulled back in the direction (left direction) Y opposite to the pulling direction (right direction in FIG. 1), the rear end of the protrusion 10 in the direction X in which the wire 9 comes out of the groove 8 An inclined portion 14 for guiding the portion to the outside is formed so that the wire 9 can be collected.

When the pipe 1 is laid in an underground hole (not shown) previously formed by the shield method, a pair of pulling wires 9, 9 are provided in the grooves 8, 8 on both sides of each clamp 2. Each may be inserted, and the leading ends of the pulling wires 9, 9 may be pulled through the underground hole. Then, the front ends of the projections 10 on the pulling wire 9 are engaged with the engaging holes 13 at the rear ends of the support wings 4 of the clamp 2, respectively, and the corrugated flexible pipes 1 are attached at intervals in the longitudinal direction. Further, since each clamp 2 is pulled, it can be easily pulled into the underground hole without being stretched and deformed.

When the laying of the pipe 1 is completed in this way, the wire 9 is pulled back in the direction opposite to the pulling direction. Then, the protrusion 10 moves away from the engagement hole 13 to the rear clamp 2, contacts the front end of the support blade 4 of the clamp 2, and moves outward along the inclined portion 14 at the front end of the support blade 4 to move to the support blade. 14
Since the wire 9 also comes off from the groove 8 in association with this, the wire 9 can be recovered.

In the above embodiment, the mounting interval s of the clamp 2 is constant, but as shown in FIG.
May be different. In this embodiment, the mounting intervals s1, s2, s3 ... Of the clamp 2 are set to be gradually longer in the pulling direction, and the mounting intervals m1 and m2 of the protrusion 10 are set.
, M3 ... are also set so as to gradually increase in correspondence with the mounting interval of the clamp 2. Therefore, when the pipe 1 is laid, the clamp 2 can be pulled at the same time, but when the wire 9 is pulled back, the clamp 2 is sequentially abutted against the inclined portion 14 of the supporting blade 4 from a direction with a short attachment interval and then detached. For,
The wire 9 can be smoothly recovered with a small force.

[0017]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) A pair of pulling wires having protrusions are inserted into the grooves on both sides of the clamp, which are attached at intervals in the longitudinal direction of the corrugated flexible pipe, at intervals corresponding to the intervals. Since the projections are engaged with the rear ends of both sides of the clamp and pulled, the long corrugated flexible pipe can be easily inserted into the underground hole and laid without being stretched and deformed. ..

(2) If inclined surfaces are formed at the front ends of both sides of the clamp to guide the protrusions in the direction in which the wire comes out of the groove when the wire is pulled back in the direction opposite to the pulling direction,
It is possible to collect the wire and it can be used repeatedly, which is economical.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a rear view of the clamp shown in FIG.

FIG. 3 is a side surface of the clamp.

FIG. 4 shows a pulling wire, (a) is a side view and (b) is a cross-sectional view.

FIG. 5 is a diagram schematically showing a method of laying a corrugated flexible pipe.

FIG. 6 is a view showing the movement of the protrusion when the tow wire is collected.

FIG. 7 is a diagram showing an example in which the mounting intervals of the clamps are different.

FIG. 8 is a vertical cross-sectional view of a corrugated flexible pipe.

9A and 9B show a deformed state of a corrugated flexible pipe, FIG. 9A is a vertical sectional view, and FIG. 9B is a horizontal sectional view.

[Explanation of symbols]

 1 Corrugated flexible pipe 2 Clamp 8 Groove 9 Traction wire 10 Protrusion

Claims (4)

[Claims] 1. A clamp having grooves on both sides of the corrugated flexible pipe at intervals in the lengthwise direction is attached, and a pair of pulling wires having protrusions at intervals corresponding to the intervals are inserted into the grooves, respectively. A method for laying a corrugated flexible pipe, characterized in that the projection is engaged with the rear ends of both sides of the clamp by a pulling wire to pull the clamp and pull the pipe into the underground hole. 2. The method of laying a corrugated flexible pipe according to claim 1, wherein the mounting intervals of the protrusions are slightly smaller than the mounting intervals of the clamps. 3. The front end of both sides of the clamp has an inclined portion that guides the protrusion in a direction in which the wire comes out of the groove when the wire is pulled back in the direction opposite to the pulling direction. The method for laying the corrugated flexible pipe according to claim 1 or 2. 4. The method of laying a corrugated flexible pipe according to claim 1, 2 or 3, wherein the clamps have different mounting intervals.