JPH10184996A - Method for changing underground buried resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and quickly change a buried resin pipe for a changing resin pipe without excavating the ground surface in which the resin pipe is buried and also without generating damage on the changing resin pipe. SOLUTION: A resin pipe extending device 10 in which a cutting blade 20 is provided on the outer peripheral surface along the longitudinal direction, the outside diameter of the front part is smaller than the inside diameter of a underground buried resin pipe M and the outside diameter of the rear part is larger than the inside diameter of the underground buried resin pipe M is inserted into the underground buried resin pipe M from an opening part Oa of the underground buried resin pipe M in a state where the end of a changing resin pipe N is fixed to the rear part and a wire W is fixed to the front end. The resin pipe extending device 10 is advanced together with the changing resin pipe N in the underground buried resin pipe M by pulling of the wire W. A diameter extending cutout is formed on the inner surface of the underground buried resin pipe M along the longitudinal direction by the cutting blade 20 in advancing, the diameter is extended by the resin pipe extending device 10 without breaking the underground buried resin pipe M by the diameter extending cutout, and the changing resin pipe N is inserted through the underground buried resin pipe M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for replacing an underground resin pipe.

[0002]

2. Description of the Related Art In recent years, resin pipes made of polyethylene or the like buried underground for water supply or the like (underground buried resin pipes).
Due to aging and increasing water supply to houses, it has become necessary to replace underground resin pipes with new pipes. Also, recent new pipes are often larger in diameter than old pipes. Conventionally, when laying a new pipe, the ground in which the old pipe is buried is excavated to expose the old pipe, and the old pipe is taken out and replaced with a new pipe.

However, in the replacement by such a method, it is necessary to excavate the ground in which the pipe is buried about 60 cm or more and to dig down until the old pipe is completely exposed, and the old pipe is buried. All ground in the part must be excavated. This work requires considerable labor and has a problem that the construction is prolonged. In addition, the old pipes may be buried directly below the road, and replacement work may hinder traffic, and excavation work may be extremely difficult under gardens and buildings.

As a method for solving these problems, a method using an excavator has been proposed (JP-A-1-27598).
4). The method involves attaching a new pipe to the rear end of an excavator having a body part whose outer diameter is larger than the existing pipe, and moving the excavator into the old pipe and crushing the old pipe to advance the old pipe. Is exchanged for a new tube.

However, in the above method, since the new pipe is laid while destroying the old pipe, broken pieces of the old pipe and earth and sand in the ground may come into contact with the new pipe and damage the new pipe. Also, in some cases, the destruction of the old pipe may cause the earth and sand surrounding the outer circumference of the old pipe to collapse, thereby blocking the laying front of the new pipe and preventing the new pipe from moving forward smoothly.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and does not excavate the ground in which a resin pipe is buried, and does not cause damage to a replacement resin pipe. Another object of the present invention is to provide a method for easily and quickly replacing an underground resin pipe with a replacement resin pipe.

[0007]

According to the present invention, a cutting blade is provided on an outer peripheral surface along a front-rear direction, an outer diameter of a front portion is smaller than an inner diameter of a resin pipe buried underground, and an outer diameter of a rear portion is smaller than that of the ground. The resin pipe expansion device, which is larger than the inner diameter of the resin pipe, is fixed from the opening of the resin pipe underground with the end of the replacement resin pipe fixed to the rear and the wire fixed to the front end. By inserting the wire into the buried resin pipe and pulling the wire, the resin pipe expanding device is advanced together with the replacement resin pipe in the buried resin pipe. A notch for diameter expansion is formed along the pipe, and the diameter of the undercut resin pipe is expanded by the resin pipe expansion device without destroying the underground resin pipe, and the replacement resin pipe is passed through the underground resin pipe. Replacement of underground resin pipes characterized by the following: According to the law.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of a resin pipe expanding device used in a method of replacing a resin pipe buried underground (hereinafter referred to as a buried resin pipe) of the present invention, FIG. 2 is a front view thereof, and FIG. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. 5 is a cross-sectional view taken along line BB of FIG. FIG. FIG. 6 is a sectional view of another resin pipe expanding device, FIG. 7 is a front view thereof, and FIG. 8 is a sectional view of still another resin pipe expanding device.

First, an example of a resin pipe expanding device used in the method for replacing a buried resin pipe of the present invention will be described.
FIG. 1 shows a cross section of the resin pipe expanding device 10, and FIG. 2 shows a front view thereof. The resin pipe expanding device 10 includes a main body part 11, a wire holding part 21, and a resin pipe holding part 2.
Consists of two.

The main body component 11 is a cylindrical member having a tapered shape whose inner and outer diameters increase from the front end to the rear end. The front end has a mounting portion 12 for mounting the wire holding component 21, and the rear end has a resin pipe. The mounting portion 13 of the holding component 22 is provided. The inner surface of the mounting portion 12 for mounting the wire holding component 21 is tapered so that the wire holding component 21 does not come off from the front end of the main body component 11. On the other hand, the rear end side of the mounting portion 13 of the resin tube holding part 22 is formed into a cylindrical screw 13a having a constant diameter and formed on an inner surface thereof, and a nut 2 having an external thread 2 described later.
6 is screwed.

The main body part 11 has an outer diameter smaller than the inner diameter of the embedded resin pipe M from the front end to the middle, and has an outer diameter larger than the inner diameter of the embedded resin pipe M from that position to the rear end. ing. A plurality of cutting blades 20 are provided upright at predetermined intervals along the front-rear direction on the front end side outer surface of the main body component 11 having an inner diameter smaller than the outer diameter of the buried resin tube M. In this example, as shown in FIG. 2, four cutting blades 20 are erected radially at intervals of 90 degrees. This cutting blade 2
0 is for forming a notch for diameter expansion along the longitudinal direction on the inner surface of the buried resin pipe M, and the diameter of a circle formed by connecting the cutting edges 20a of the four cutting blades 20 is equal to the cutting blade diameter. 20
At the rear end side, and the diameter of the maximum portion is larger than the inner diameter of the buried resin tube M and smaller than the outer diameter. Thereby, when the buried resin pipe expanding device 10 passes through the buried resin pipe M, the cutting blade 20 cuts the buried resin pipe M without cutting and separating the buried resin pipe M along the longitudinal direction on the inner surface of the buried resin pipe M. Cuts are formed.
The cutting blade 20 is preferably provided so as to cut the pipe wall of the buried resin pipe M while leaving 2 to 50% of its thickness. The number of the cutting blades 20 is determined as appropriate.

The wire holding part 21 is for attaching a wire W for advancing the resin pipe expanding device 10 in the buried resin pipe M to the main body part 11. Consisting of The tapered nut 24 with an inner thread is accommodated in the mounting portion 12 of the wire holding component 21 in the main body component 11 and has a diameter that does not come off from the front end of the main body component 11. Further, the bar screw 23 is provided with the tapered nut 24 having the inner thread.
One end is screwed to the inner screw 24a, and the other end protrudes forward of the tapered nut 24 with the inner screw. A nut 28 fixed to the tip of the wire W is screwed to the other end of the bar screw 23 protruding, whereby the tip of the wire W is fixed to the front end of the main body component 11.

The resin tube holding part 22 comprises a pipe holding ring 25, an externally threaded nut 26 and a pipe in core 27. The outer surface of the pipe pressing ring 25 is pressed against the inner surface of the mounting portion 13 of the resin tube holding component 22 in the main body component 11, and is pressed by the tapered inner surface of the mounting portion 13 by advancing to reduce the diameter. The outer diameter of the replacement resin tube N is substantially equal to the outer diameter of the replacement resin tube N, and the inner surface thereof has a saw-tooth-shaped projection 25a that cuts into and engages with the outer surface of the replacement resin tube N. Is formed. One end of the replacement resin pipe N is inserted into the pipe holding ring 25.

The external screw nut 26 moves the pipe holding ring 25 forward and backward to change the inner diameter of the pipe holding ring 25, thereby forming a projection 25 a on the inner surface of the pipe holding ring 25 on the outer surface of the replacement resin pipe N. The replacement resin pipe N is fixed by being bitten, or the bite is released so that the resin pipe expanding device 10 can be removed from the replacement resin pipe N. This external screw nut 2
Reference numeral 6 denotes an inner diameter substantially equal to or larger than the outer diameter of the replacement resin pipe N, and is in contact with the rear end of the pipe holding ring 25 and the rear end of the mounting portion 13 of the resin pipe holding part 22 of the main body part 11. And the pipe press ring 25 is moved forward and backward by rotating forward and backward.

The pipe in-core 27 is tightened by the pipe holding ring 25 when the pipe holding ring 25 is reduced in diameter by advancing and the projection 25a of the pipe holding ring 25 bites into the outer surface of the end of the replacement resin pipe N. So that the replacement resin pipe N is not broken.
To support the inner surface of the The pipe-in-core 27 has an outer diameter that is substantially equal to the inner diameter of the replacement resin pipe N, and is attached to the inner surface of the distal end of the replacement resin pipe N.

Next, an example of a method for replacing a buried resin pipe according to the present invention using the above-mentioned resin pipe expanding apparatus will be described with reference to FIGS. First, the resin pipe expanding device 10 in which the tip of the replacement resin pipe N is fixed to the rear part as described above is positioned at the opening Oa such as the end of the buried resin pipe M as shown in FIG. . One end of a wire W passed through the embedded resin pipe M is fixed to the front end of the resin pipe expanding device 10 via the wire holding component 21. Then, the other end of the wire W that has been brought out to the ground G from another opening Ob of the embedded resin pipe M is wound by a winch or the like, and the resin pipe expanding device 10 is pulled forward in the embedded resin pipe M.

The resin pipe expanding device 10 pulled forward by the winding of the wire W has a cutting blade 20 on the outer surface.
Thereby, as shown in FIG. 4, while forming the diameter-enlarging cut C along the longitudinal direction on the inner surface of the embedded resin pipe M and expanding the embedded resin pipe M by the large-diameter portion at the rear part of the main body component 11, It advances inside the buried resin pipe M together with the rear replacement resin pipe N. At this time, the diameter of the buried resin pipe M is expanded by expanding the notch C for expanding the inner surface of the buried resin pipe M, so that the buried resin pipe M is not broken. Since the replacement resin pipe N advances inside the buried resin pipe M after the diameter expansion, the buried resin pipe M can be easily replaced. In addition, since the replacement resin tube N advances and the resin tube is replaced within the buried resin tube M that has not been broken, the replacement resin tube N is not damaged by fragments of the buried resin tube M or the like. Resin tube N
The buried resin pipe M can be smoothly replaced without the laying place being blocked by the soil.

The resin pipe expanding device used in the present invention is not limited to those shown in FIGS. FIG.
Is a cross-sectional view of another example of the resin pipe expanding device 30, and FIG. 7 is a front view thereof. In the resin pipe expanding device 30 of this example, a wire Wa is passed through a center hole 32 of a tapered tubular main body part 31, and an end of the wire Wa is connected to the main body part 31.
It is fixed to the rear end.

The outer surface of the rear part of the main body part 31 has a small diameter through a step 33, and a screw 34 is formed on the outer surface within a predetermined length. Further, the portion behind the screw 34 has an inverse tapered shape in which the diameter becomes smaller toward the rear, as opposed to the front side of the main body component 31. The reverse tapered portion 35 has a rear end with an outer diameter smaller than the inner diameter of the replacement resin tube Na and a front end with an outer diameter larger than the inner diameter of the replacement resin tube Na. Can be fitted. A resin pipe fixing part 42 having a screw 42a on the front inner surface and a serrated protrusion 42b on the rear inner surface.
Is fitted on the outer surface of the front end of the replacement resin tube Na and screwed into the screw 34 at the rear of the main body part 31. As a result, the front outer surface of the replacement resin tube Na is
And replace the inner saw blade-shaped protrusion 42b with the resin tube N for replacement.
The resin tube Na for replacement is fixed to the main body part 31 by biting into the outer surface of a. Reference numeral 40 denotes a cutting blade attached to the outer surface of the main body part 31.

FIG. 8 shows still another example of a resin pipe expanding device 50.
Is shown. The resin pipe expanding device 50 includes a main body part 51 and a cutting blade part 53 to which the cutting blade 60 is attached so that the wire Wb and the replacement resin pipe Nb can be easily attached and detached.
, A wire end fixing part 52, and a replacement resin pipe fixing part 62, and the parts 51, 53, 52,
62 are separably coupled. Further, on the outer surface of the main body component 51, a rib (not shown) extending in the longitudinal direction is used to reduce the resistance to the inner surface of the embedded resin tube Mb when the resin pipe expanding device 50 advances inside the embedded resin tube Mb. ) Are formed at predetermined intervals. This rib is preferably provided on the main body component in the other embodiment.

[0021]

As shown and described above, according to the method for replacing a buried resin pipe of the present invention, it is not necessary to dig up the ground to replace the buried resin pipe, and an opening for inserting a wire and its opening are provided. It is enough to have an opening to pull the wire, so workability is greatly improved compared to the conventional replacement method that required excavation to expose the buried resin pipe, the time required for replacement is shortened, and The work can be performed irrespective of the place where the resin pipe is buried, such as the place where a building exists on the ground.

In addition, a new replacement pipe having a diameter larger than that of the buried resin pipe is laid in the buried resin pipe while expanding the diameter without breaking the buried resin pipe. The new pipe can be prevented from being damaged by stones, etc., and the durability of the new pipe can be increased after laying. In addition, the place where the new pipe is laid is not blocked by soil, so the new pipe can be laid smoothly. There is also an effect that can be done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a resin pipe expanding device used in the method for replacing a buried resin pipe of the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a diagram schematically illustrating a method of replacing a buried resin pipe according to the present invention.

FIG. 4 is a cross-sectional view taken along line AA of FIG.

FIG. 5 is a cross-sectional view showing an enlarged diameter of the embedded resin pipe cut along a line BB in FIG. 3;

FIG. 6 is a sectional view of another resin pipe expanding device.

FIG. 7 is a front view of FIG. 6;

FIG. 8 is a sectional view of another resin pipe expanding device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Resin pipe expanding device 11 Body part 12 Wire holding part mounting part 13 Resin pipe holding part mounting part 20 Cutting blade 21 Wire holding part 22 Resin pipe holding part 23 Bar screw 24 Taper nut 25 Pipe holding ring 27 Pipe in core 28 Nut Oa Opening Ob Opening M Buried Resin Pipe N Replacement Resin Pipe W Wire C Enlarged Cut

Claims (1)

[Claims] 1. A cutting blade is provided on an outer peripheral surface along a front-rear direction, an outer diameter of a front portion is smaller than an inner diameter of a resin tube buried underground, and an outer diameter of a rear portion is larger than an inner diameter of the resin tube buried underground. The resin pipe expanding device was inserted into the underground resin pipe from the opening of the underground resin pipe with the end of the replacement resin pipe fixed at the rear and the wire fixed at the front end, By pulling the wire, the resin pipe expanding device is advanced in the underground resin pipe together with the replacement resin pipe, and at the time of the advance, the cutting blade is used to make a notch for diameter expansion along the longitudinal direction on the inner surface of the underground resin pipe. Underground burial characterized by forming and expanding the diameter with a resin pipe expanding device without destroying the resin pipe buried underground by the notch for diameter expansion, and passing the replacement resin pipe through the resin pipe underground buried How to replace resin pipes.