JP2024043729A - Existing pipe rehabilitation method - Google Patents

Abstract

[Problem] In a method for rehabilitating an existing pipe using an expand pipe manufacturing method, the present invention prevents breakage of the take-up wire due to twisting during pipe manufacturing, and prevents damage to the connection between the wires due to tensile load during pipe manufacturing. [Solution] A band-shaped member 10 is wound in a spiral shape to join adjacent edge portions to manufacture a spiral rehabilitating pipe 3 with a smaller diameter than the existing pipe 1, and the pipe is twisted into the existing pipe. At the beginning of the pipe manufacturing process, a connection end 22e of a take-up wire 22 is connected to an extension end 21e of a cutting wire 21 extending from a pipe end 3e of the rehabilitating pipe 3. After the pipe manufacturing process of the rehabilitating pipe 3, a rotary joint 30 is removed, and the connection end 22e and the extension end 21e are connected. Then, the take-up wire 22 is taken off to cut a part of the joint 15 between the adjacent edge portions, and the binding force of the joint 15 is gradually weakened from the second side to the first side. At the same time, the circumferential length of the weakened portion of the rehabilitating pipe 3 is expanded.

Description

The present invention relates to a method for rehabilitating existing pipes such as aging sewer pipes, and in particular, a method for rehabilitating an existing pipe after forming a helical rehabilitation pipe along the inner circumference of the existing pipe so that it has a smaller diameter than the inner diameter of the existing pipe. The present invention relates to a method for rehabilitating existing pipes using an expansion pipe manufacturing method that expands the circumference of the pipe.

There is a known method of rehabilitating existing pipes, such as aging sewer pipes, by constructing a spiral tubular rehabilitation pipe made of band-shaped members (profiles) along the inner periphery of the pipe (see Patent Document 1, etc.) ).

For example, Patent Document 1 discloses an existing pipe rehabilitation method using the so-called expanded pipe manufacturing method. Specifically, a main push-type pipe making machine is installed in the manhole on the starting side. The pipe making machine winds a strip member in a spiral shape and joins the adjacent edge portions with concave and convex fitting, thereby making it possible to manufacture a helical rehabilitated pipe to a diameter smaller than the inner diameter of the existing pipe. , Push the rehabilitated pipes into the existing pipes one by one. During tube manufacturing, a cutting wire is interposed between adjacent edge portions of the strip member. When the tip of the rehabilitated pipe in the pushing direction reaches the pipe opening on the reaching side, the tip in the pushing direction (the end on the reaching side) is fixed. Then, by pulling the cutting wire, a portion of the joint between the adjacent edge portions is sequentially cut along the winding direction, thereby weakening the joining force. At the same time, the belt-like member is further supplied to the rehabilitated pipe by the pipe making machine, thereby twisting and rotating the starting end of the rehabilitated pipe. As a result, the adjacent edges of the joint where the joining force has been weakened due to the cutting slip, and the circumference of the rehabilitated pipe is gradually expanded (diameter enlarged) from the reaching side to the starting side. Attached to the inner surface.

JP2021-126830A

In the expand pipe manufacturing method, for example, a take-up wire is passed from the starting side (first side) to the destination side (second side) inside the rehabilitated pipe at the beginning of pipe manufacturing, and is connected to the end of the cutting wire that extends from the end of the destination side (second side) of the rehabilitated pipe. Thereafter, as the rehabilitated pipe is expanded, the cutting wire and take-up wire are each paid out from the starting side (first side).

On the other hand, the rehabilitated pipe that is being manufactured by the original push-type pipe manufacturing machine is pushed toward the reaching side (second side) while being rotated. Therefore, if the cutting wire and the take-off wire are connected so that rotational force can be transmitted, there is a risk that the take-off wire will continue to be twisted and break during the tube manufacturing process. In order to avoid this, it is conceivable to provide a rotary joint (swivel) between the cutting wire and the take-up wire to cut off the rotational force.

However, rotating joints cannot be expected to have high strength against tensile loads. Therefore, when the pulling wire is used to cut a part of the joint between adjacent edges of the rehabilitated pipe, a tensile load that exceeds the tensile strength of the rotary joint is applied, causing damage to the rotary joint and the wire. There is a risk of damage to the connecting parts. In particular, if the portion to be cut is thick or if the band-shaped member is so rigid that it is difficult to pull out the cutting wire, a considerably large tensile load is required and the rotary joint is likely to be damaged. Furthermore, there is a risk that the rotary joint may be damaged due to contact with a take-up guide such as a pulley on the take-up route.
In view of the above circumstances, the present invention has been developed to prevent breakage due to twisting of wires for taking over pipes during pipe manufacturing, and to prevent damage to joints between wires due to tensile loads during take-off, in a method for rehabilitating existing pipes using the expanded pipe manufacturing method. The purpose is to prevent.

In order to solve the above-mentioned problems, the present invention involves manufacturing a helical rehabilitated pipe, which is formed by winding a band member in a spiral shape and joining adjacent edge portions at one turn offset, to a diameter smaller than the inner diameter of the existing pipe. At the same time, after the pipe manufacturing step of screwing the existing pipe from the first side to the second side in the pipe axial direction, the restraining force between the adjacent edge portions of the rehabilitated pipe is applied from the second side to the second side. a constraint weakening step of sequentially weakening toward the first side; and an expansion step of twisting the pipe end of the first side of the rehabilitated pipe to expand the circumference of the weakened portion of the rehabilitated pipe. , an existing pipe rehabilitation method,
a wire intervening step of interposing a cutting wire between the adjacent edge portions during the joining in the pipe manufacturing step;
At the beginning of the pipe manufacturing process, a connecting end of the take-off wire is passed from the first side to the second side in the rehabilitated pipe, and extends from the pipe end on the second side of the rehabilitated pipe. a rotatable connection step of relatively rotatably connecting the extending end of the cutting wire via a rotary joint;
After the pipe manufacturing step and before the start of the constraint weakening step, the rotary joint is removed and the connecting end portion and the extending end portion are connected via a connecting means having a higher tensile strength than the rotary joint. tensile strength connection process;
By pulling the pulling wire to the first side from the beginning to the middle of the constraint weakening step, and then pulling the cutting wire, a part of the joint between the adjacent edge portions is removed. is cut by the cutting wire.

According to the rehabilitation method, even if the extending end of the cutting wire rotates as the rehabilitated pipe rotates in the pipe manufacturing process after the rotatable connection process, the rotational force is removed by cutting off the edge using the rotary joint. You can prevent the wire from rotating. Therefore, it is possible to prevent the take-up wire from being excessively twisted and broken.
In addition, prior to the constraint weakening process and the expansion process, the take-off wire and the cutting wire are reconnected using a high tensile strength connecting means, so that when the take-off wire is pulled and the cutting wire is taken off, the take-off wire is Also, it is possible to prevent the connecting portion between the cutting wires from being unable to withstand the tensile load and being damaged. In particular, a considerably large wire is required because the part to be cut is thick at the joint between adjacent edges of the rehabilitated pipe, or the strip member is so rigid that it is difficult to pull out the cutting wire. Even if the wires are connected to each other, it is possible to reliably prevent the connecting portions between the wires from being damaged.
Furthermore, the rotary joint will not be damaged by contact with a take-up guide such as a pulley on the take-up route.

Preferably, in the high tensile strength connecting step, the connecting end and the extending end are connected via a crimping fitting that is crimped to these ends. The crimp fitting constitutes a connection means with higher tensile strength than the rotary joint. Preferably, the crimp fitting has a cylindrical shape through which the connecting end and the extending end can be inserted.

According to the present invention, in a method for rehabilitating an existing pipe using the expand pipe manufacturing method, it is possible to prevent breakage of the take-up wire due to twisting during pipe manufacturing. It is also possible to prevent damage to the connection between the wires due to the tensile load during take-up.

FIG. 1 is a front sectional view showing an existing pipe that is being rehabilitated by the expanded pipe manufacturing method according to the first embodiment of the present invention at an early stage of the pipe manufacturing process. Fig. 2(a) is a cross-sectional view of a band-shaped member taken along line IIa-IIa in Fig. 1. Fig. 2(b) is a cross-sectional view of a rehabilitated pipe during a pipe-making process, showing an enlarged view of a circular portion IIb in Fig. 1. Fig. 2(c) is a cross-sectional view of a rehabilitated pipe during a restraint weakening process, showing an enlarged view of a circular portion IIc in Fig. 5. FIG. 3 is a front view of a wire connection section including a rotary joint in the pipe manufacturing process. FIG. 4(a) is a front view showing the wire connection portion including the crimp joint in the constraint weakening process and the expansion process in a state before crimping. FIG. 4(b) is a front view of the wire connection portion including the crimped joint. FIG. 5 is a front sectional view showing the existing pipe undergoing rehabilitation work in a restraint weakening process and an expansion process. FIG. 6 is a cross-sectional view showing a wire connecting portion including a crimp joint according to a second embodiment of the present invention, taken along a cut surface perpendicular to the axis of the crimp joint. FIG. 7 is a cross-sectional view showing a wire connection portion including a crimp joint according to a third embodiment of the present invention, taken along a cut plane orthogonal to the wire. FIG. 8 is a front view of a wire connecting portion including a crimp joint according to a fourth embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First Embodiment
As shown in Fig. 1, an existing deteriorated pipe 1 is rehabilitated by lining its inner periphery with a rehabilitation pipe 3. The existing pipe 1 to be rehabilitated is, for example, a sewerage pipe buried underground, but the present invention is not limited to this and may be a water supply pipe, an agricultural water pipe, a gas pipe, a hydroelectric power generation water pipe, a tunnel, etc.

As shown in FIG. 2(a), the rehabilitated pipe 3 is composed of a strip member 10 (profile). The band-shaped member 10 is made of synthetic resin such as polyvinyl chloride (PVC) and has a constant cross-sectional shape. In this embodiment, the strip member 10 has a plurality of hollow ribs 12 having a square cross section. Two male and female fitting portions 13 and 14 are provided on both edges of the band member 10 in the width direction.

The existing pipe 1 is rehabilitated as follows.
<Pipe manufacturing process>
As shown in Figure 1, a push-type pipe making machine 8 is prepared and installed in a starting side manhole 4 connected to the starting side (first side) pipe end 1d of the existing pipe 1. A belt-shaped member 10 is successively unwound from a drum 7 on the ground and supplied to the pipe making machine 8. In the pipe making machine 8, the belt-shaped member 10 is wound spirally and the fitting portions 13, 14 of adjacent edge portions shifted by one revolution are joined by fitting together in a concave-convex manner (Figure 2(b)), thereby successively producing a helical tubular rehabilitating pipe 3. A helical joint 15 is formed by the fitting portions 13, 14 that are fitted together in a concave-convex manner. At the joint 15, the adjacent edge portions are constrained to each other.
In the pipe manufacturing process, the rehabilitating pipe 3 is manufactured to have an inner diameter smaller than that of the existing pipe.

Preferably, as shown in FIG. 2(b), for example, a moisture curing adhesive 16 is in the fitting groove 13a of the two groove-shaped fitting grooves 13a and 13b of the female fitting part 13. Filled. A hot melt adhesive 17 is filled in the fitting groove 13b. Of the two protrusions 14a and 14b of the male fitting portion 14, the protrusion 14a is slidably fitted into the fitting groove 13a. The protrusion 14b is fitted into the fitting groove 13b and bonded.

<Wire intervening process>
In parallel with the pipe-making process, the cutting wire 21 is introduced from the delivery roll 23 into the pipe-making machine 8, and is interposed between the fitting parts 13 and 14 (adjacent edge parts) during joining ( Figure 2(b)). Specifically, the cutting wire 21 is placed between the two protrusions 14a and 14b, and the fitting portion 13 is placed over and sandwiched between the two protrusions 14a and 14b. The end portion 21e of the cutting wire 21 is extended into the inside of the rehabilitation pipe 3 from near the tip of the rehabilitation pipe 3, that is, the pipe end 3e on the reaching side (second side).

<Rotable connection process>
As shown in FIG. 1, at the initial stage of the pipe manufacturing process, for example, when the number of spiral turns of the rehabilitated pipe 3 is several, the connection end 22e of the take-off wire 22 is connected to the starting side (inside the rehabilitated pipe 3). (first side) to the destination side (second side). Then, the extending end 21e of the cutting wire 21 and the connecting end 22e of the take-up wire 22 are connected via a rotary joint 30 (swivel).

As shown in FIG. 3, the rotary joint 30 includes a pair of connecting parts 31 and a rotary coupling part 32 between the connecting parts 31. The connecting parts 31 on both sides are coupled via the rotary coupling part 32 so that they can rotate relative to each other. The rotary coupling part 32 may have a bearing.

The extending end 21e of the cutting wire 21 is connected, for example, in a ring shape, to one connecting part 31, and the connecting end 22e of the take-up wire 22 is connected, for example, in a ring shape to the other connecting part 31. Ru. As a result, the cutting wire 21 and the take-up wire 22 are connected via the rotary joint 30 so as to be relatively rotatable.

In the pipe making process, the rehabilitating pipe 3 made by the push-type pipe making machine 8 is screwed into the existing pipe 1 in sequence. That is, as shown by the white arrow a in FIG. 1, the rehabilitating pipe 3 is pushed in while being rotated. As a result, the rehabilitating pipe 3 is extended in sequence toward the end (second side) of the existing pipe 1 in the pipe axial direction. As the rehabilitating pipe 3 is extended, the cutting wire 21 is sequentially unwound from the unwinding roll 23 and embedded in the joint 15 of the rehabilitating pipe 3, so as to be wound in a spiral shape along the joint 15, and the take-up wire 22 is sequentially unwound from the take-up winch 24 in a free-rotating state and stretched inside the rehabilitating pipe 3. The connection portion 25 between the wires 21 and 22, including the rotary joint 30, is rotated in the circumferential direction of the pipe end 3e of the rehabilitating pipe 3 while being moved toward the end 1e on the end (second side) of the pipe end 3e. On the other hand, the cutting wire 21 and the take-up wire 22 are prevented from rotating with each other by the rotary joint 30, so the rotation of the cutting wire 21 is not converted into twisting of the take-up wire 22. Therefore, the take-up wire 22 does not continue to be twisted during pipe making, and the take-up wire 22 does not become excessively twisted and break.

As shown by the two-dot chain line in FIG. 1, by forming the pipe in this way until the pipe end 3e of the rehabilitated pipe 3 reaches the pipe end 1e on the reaching side (second side) of the existing pipe 1, The pipe manufacturing process is completed.
Next, the pipe end 3e of the rehabilitated pipe 3 is prevented from rotating relative to the pipe end 1e of the existing pipe 1.

<High tensile strength connection process>
Before and after the rotation is stopped, the rotary joint 30 is removed, and the extending end 21e of the cutting wire 21 and the connecting end 22e of the take-up wire 22 are once separated.
Subsequently, as shown in FIG. 4, the extending end 21e of the cutting wire 21 and the connecting end 22e of the take-up wire 22 are connected via the crimp fitting 40 (connecting means). The crimp fitting 40 has a higher tensile strength than the rotary joint 30. The crimping fittings 40 are crimped onto the extending end 21e of the cutting wire 21 and the connecting end 22e of the take-off wire 22, respectively.

More specifically, as shown in Fig. 4(a), the crimping fitting 40 has a cylindrical shape before crimping. The extending end 21e of the cutting wire 21 and the connecting end 22e of the take-up wire 22 are inserted into the crimping fitting 40 from opposite directions, and then the crimping fitting 40 is crimped. As shown in Fig. 4(b), a concave crimping mark 40d is formed in the crimping fitting 40. Preferably, multiple locations (two locations in Fig. 4(b)) in the axial direction of the crimping fitting 40 are crushed from multiple directions (directions shifted by approximately 90° in Fig. 4(b)).

More preferably, the connecting means is made up of multiple crimping fittings 40 (three in FIG. 4). These crimping fittings 40 are lined up in a row, and the ends 21e, 22e of the wires 21, 22 are inserted and crimped. This forms a wire connecting portion 25A made up of multiple crimping fittings 40 and the wire ends 21e, 22e, which has a higher tensile strength than that obtained during the pipe making process.

<Restraint Weakening Process>
Next, as shown in Fig. 5, the take-up winch 24 is rotated in the take-up direction to take-up the take-up wire 22 to the starting side (first side). As a result, as shown in Fig. 2(c), the portion 21c of the cutting wire 21 that is drawn out from the joint 15 to the inside of the rehabilitating pipe 3 is strongly pulled to the starting side (left side in Fig. 5). The drawn-out portion 21c cuts the root portion 14c (part of the joint 15) of the protruding strip 14b. By continuing the take-up operation of the take-up wire 22, the drawn-out portion 21c is moved in a spiral shape to the starting side (first side) along the winding direction of the rehabilitating pipe 3, and the root portion 14c is cut in sequence. As a result, the binding force of the fitting portions 13, 14 (adjacent edge portions) of the rehabilitating pipe 3 is gradually weakened from the arrival side (second side) to the starting side (first side).

<Expansion process>
As shown in Fig. 5, the push-type pipe making machine 8 is driven in parallel with the driving of the take-up winch 24 to further supply the strip-shaped member 10 to the rehabilitating pipe 3. As a result, as shown by the white arrow b in Fig. 5, the starting pipe end 3d of the rehabilitating pipe 3 is twisted, and the small-diameter unexpanded pipe section 3a from the starting-side (first side) pipe end 3d of the rehabilitating pipe 3 to the pull-out section 21c is rotated. The fitting parts 13, 14 of the joint 15 slide relative to each other in the winding direction in the part 3c of the rehabilitating pipe 3 on the arrival side (right side in Fig. 5) of the pull-out section 21c, in which the joint strength is weakened, are sequentially expanded (expanded in diameter). As a result, the rehabilitating pipe 3 becomes the large-diameter expanded pipe section 3b through the cone section 3c, and is attached to the inner circumferential surface of the existing pipe 1.
At this point, the moisture-curing adhesive 16 is not yet cured, and the mating portions 13, 14 are allowed to slide relative to each other.

In the above-mentioned constraint weakening process, a large tensile load acts on the take-up wire 22 and the cutting wire 21. In turn, a large tensile load acts on the connecting portion 25A between these wires 21, 22. On the other hand, the wire connecting means of the connecting portion 25A during the constraint weakening process is replaced with a high tensile strength crimping fitting 40 instead of a rotary joint 30, so that the connecting portion 25A can fully withstand the large tensile load. In particular, in this embodiment, as shown in FIG. 2, the portion 14c to be cut is thick, and the belt-shaped member 10 is structured so that it is difficult to elastically deform and the cutting wire 21 is difficult to pull out from between the fitting portions 13, 14, so that a tensile force greater than normal is required, but the connecting portion 25A can withstand the tensile load, and the connecting portion 25A can be prevented from being damaged.

From the beginning to the middle of the constraint weakening process, the take-off wire 22 is taken off and wound around the take-off winch 24.
As shown in FIG. 5, the connecting portion 25A is brought out from the inside of the rehabilitation pipe 3 to the ground via the starting side manhole 4. A pulley 26 (take-up guide) is arranged on the take-up route. When the connecting portion 25A passes the pulley 26, the crimp fitting 40 comes into contact with the pulley 26, but the crimp fitting 40 is not damaged thereby.
Eventually, the connecting portion 25A is wound up by the take-off winch 24.
Thereafter, the cutting wire 21 is directly taken off by the take-off winch 24.

In this way, the entire area from the pipe end 3e to the pipe end 3d of the rehabilitated pipe 3 is expanded and attached to the inner surface of the existing pipe 1.
Thereafter, the moisture-curable adhesive 16 (FIG. 2(b)) is cured, and the fitting parts 13 and 14 are bonded and fixed together.

Next, other embodiments of the present invention will be described. In the following embodiments, the same reference numerals are given to the same components in the drawings, and the explanation thereof will be omitted.
<Second embodiment (Fig. 6)>
As shown in FIG. 6, the crimping fitting 41 of the second embodiment is a modification of the cylindrical crimping fitting 40 (FIG. 4) of the first embodiment, and is formed into a cylindrical shape with an elliptical or oblong cross section. has been done.

<Third embodiment (Fig. 7)>
As shown in FIG. 7, the crimping fitting 50 (connecting means) of the third embodiment has a generally U-shaped body 51, a U-shaped holding member 52, and a pair of tightening screws 53. . After passing the extending end 21e of the cutting wire 21 and the connecting end 22e of the take-up wire 22 through the insertion hole 54 formed by the body 51 and the holding member 52, the tightening screw 53 is tightened. As a result, the wires 21 and 22 are strongly sandwiched and crimped between the body 51 and the pressing member 52.

<Fourth embodiment (FIG. 8)>
As shown in FIG. 8, the crimping fitting 60 (connecting means) of the fourth embodiment includes a cylindrical body 61 and a plurality of (two in the figure) tightening screws 63 provided on the side of the body 61. have. After passing the extending end 21e of the cutting wire 21 and the connecting end 22e of the take-up wire 22 through the insertion hole 64 of the body 61, the tightening screw 63 is tightened. As a result, the wires 21 and 22 are strongly pinched and crimped between the inner peripheral surface of the insertion hole 64 of the body 51 and the tightening screw 63.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the connecting means for connecting the take-up wire 22 and the cutting wire 21 in the high tensile strength connecting process need only have a higher tensile strength than the rotary joint 30, and is not limited to using a member separate from the wires 21, 22, such as a crimping fitting, but may also be a knot formed by directly tying the take-up wire 22 and the cutting wire 22 together.
The cross-sectional shape of the belt-shaped member is not limited to that of the above embodiment, and various shapes can be adopted, such as a T-shaped cross section instead of the hollow rectangular cross section of the rib 12.

The present invention can be applied to technology for rehabilitating existing pipes, such as aging sewer pipes.

1 Existing pipe 1d Starting side (first side) pipe end 1e End portion on the arrival side (second side) 3 Rehabilitation pipe 3a Small diameter unexpanded pipe section 3b Large diameter expanded pipe section 3c Cone section (part where joint strength is weakened)
3d: starting side (first side) pipe end 3e: arrival side (second side) pipe end 8: main push type pipe making machine 10: belt-shaped member 12: ribs 13, 14: mating portion (adjacent edge portion)
14c Root part (part of joint)
15 Joint 21 Cutting wire 21c Pull-out portion 21e Extension end 22 Take-up wire 22e Connection end 23 Pay-out roll 24 Take-up winch 25 Rotatable wire connection 25A High tensile strength wire connection 26 Pulley (take-up guide)
30 Rotary joint 31 Pair of connecting parts 32 Rotary connecting part 40 Crimping metal fitting (connecting means)
41 Crimping fitting (connecting means)
50 Crimping fitting (connecting means)
60 Crimping fitting (connecting means)

Claims (3)

A method for rehabilitating an existing pipe, comprising the steps of: manufacturing a helical rehabilitating pipe, which is formed by helically winding a belt-shaped member and joining adjacent edge portions with a one-turn offset, to a diameter smaller than the inside diameter of an existing pipe and twisting the helical rehabilitating pipe from a first side to a second side in the pipe axial direction within the existing pipe; carrying out a restraint weakening process for successively weakening the restraint force between the adjacent edge portions of the rehabilitating pipe from the second side to the first side; and an expansion process for twisting the pipe end on the first side of the rehabilitating pipe to expand the circumferential length of the rehabilitating pipe at the portion where the weakening has been released,
a wire interposing step of interposing a cutting wire between the adjacent edge portions during the joining in the pipe making step;
a rotatable connecting step in which, at the beginning of the pipe making step, a connection end of a take-off wire is passed from the first side to the second side within the rehabilitating pipe, and the connection end of the take-off wire is connected via a rotary joint to an extended end of the cutting wire extending from the pipe end on the second side of the rehabilitating pipe so as to be rotatable relative to the extended end of the cutting wire.
a high tensile strength connecting step of removing the rotary joint after the pipe making step and before the start of the restraint weakening step, and connecting the connection end and the extension end via a connecting means having high tensile strength through the rotary joint;
a pull-up wire is pulled toward the first side from the beginning to the middle of the restraint weakening process, and thereafter, the cutting wire is pulled, thereby cutting a portion of the joint between the adjacent edge portions with the cutting wire. The existing pipe rehabilitation method according to claim 1, wherein in the high tensile strength connecting step, the connecting end and the extending end are connected via a crimping fitting that is crimped to these ends. The method for rehabilitating an existing pipe according to claim 2, wherein the crimping fitting is tubular and allows the connection end and the extension end to be inserted therethrough.

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