JP2024085729A - Existing pipe rehabilitation method and pipe making machine for use in said method - Google Patents

Abstract

[Problem] To provide a finishing method in an expander pipe manufacturing method that can smoothly expand the pipe end portion of a rehabilitation pipe and reduce the workload of workers after cutting and releasing.
[Solution] A strip-shaped member 10 is wound helically around the inner circumference of an outer periphery restrictor 21 of an end pipe making machine 20 to make a helical rehabilitating pipe 3 with a smaller diameter than the existing pipe 1. Then, the binding force of the spiral joint 12 is gradually weakened from the tip side of the rehabilitating pipe 3 in the pushing direction toward the end side, and the end pipe making machine 20 feeds a subsequent strip portion 19 of the strip-shaped member 10 into the rehabilitating pipe 3 to expand the circumferential length of the part of the rehabilitating pipe 3 where the binding has been weakened, and attach it to the inner circumferential surface of the existing pipe 1. When the distance from an end 32f of a cone portion 32 on the large diameter pipe portion 33 side between the attached large diameter pipe portion 33 and small diameter pipe portion 30 in the rehabilitating pipe 3 to the end pipe making machine 20 becomes within a predetermined length L, the outer periphery restrictor 21 is preferably expanded in diameter stepwise.
[Selected figure] Figure 7

Description

The present invention relates to a method for rehabilitating existing pipes, which uses the so-called expander method to construct a helical rehabilitating pipe along the inner circumference of an aged existing pipe, and a pipe-making machine used in the method, and in particular to a finishing method used after the expansion of the rehabilitating pipe has reached the vicinity of the pipe-making machine.

A method for rehabilitating an existing pipe, such as an aging sewer pipe, by constructing a spiral rehabilitation pipe made of a strip-shaped member (profile) along the inner circumference of the existing pipe is known (see Patent Documents 1 to 3, etc.). Patent Document 1 discloses an end-pushing pipe making machine for making a rehabilitation pipe. The end-pushing pipe making machine has an annular outer periphery regulating body and is installed in a starting manhole connected to the existing pipe. The belt-shaped member is wound in a spiral shape along the inner circumference of the outer periphery regulating body and the adjacent edges are joined by a concave-convex fit, making a spiral rehabilitation pipe with a diameter smaller than the inner diameter of the existing pipe, while gradually pushing the rehabilitation pipe into the existing pipe.

Patent Documents 2 and 3 disclose a method for rehabilitating an existing pipe using the so-called expander method. In detail, when a rehabilitated pipe is produced from a band-shaped member by a pipe-making machine at the starting manhole, a restraint weakening wire is interposed between the adjacent edges of the band-shaped member. When the tip of the rehabilitated pipe in the pushing direction reaches the pipe opening on the destination side, the tip in the pushing direction (the end on the destination side) is fixed, and the restraint weakening wire is withdrawn to sequentially cut the convex strips that constitute part of the joint between the adjacent edges along the winding direction, thereby weakening the joint force. At the same time, the band-shaped member is further supplied to the rehabilitated pipe by the pipe-making machine at the starting side, twisting and rotating the start side end of the rehabilitated pipe. As a result, the adjacent edges of the joint with the weakened joint force slide against each other, and the circumference of the rehabilitated pipe is sequentially expanded (increased in diameter) from the destination side to the starting side, and is attached to the inner surface of the existing pipe.

JP 2011-106561 A JP 2021-115749 A JP 2021-115750 A

The expander method does not require the process of injecting backfill material, and is expected to shorten construction time and reduce construction costs compared to other methods. On the other hand, during construction, it is important to manage the length of the cone section (hereinafter referred to as "cone length") that expands from the unexpanded small diameter pipe section of the rehabilitated pipe to the expanded large diameter pipe section. If the cone length is too long, poor adhesion to the inner surface of the existing pipe occurs. If the cone length is too short, the angle of the cone becomes too steep, causing buckling (breakage of the uneven fit between adjacent edge parts) between the unexpanded small diameter pipe section and the cone section. In particular, in the finishing stage after the rehabilitated pipe is expanded close to the pipe end on the starting manhole side, the cone length cannot be secured sufficiently, and buckling is likely to occur. This is because, in existing pipes such as sewers, the starting manhole is generally narrow, and the original extrusion pipe making machine can only be located about 200 mm away from the pipe mouth of the existing pipe.

In the finishing methods described in Patent Documents 2 and 3, when the expansion reaches near the end of the rehabilitated pipe on the starting manhole side, the head pipe making machine is stopped, the restraint weakening wire is pulled to a position immediately adjacent to the head pipe making machine, the rehabilitated pipe is cut at that position and released from the head pipe making machine, and the cone-shaped pipe end portion of the released rehabilitated pipe is manually twisted to manually expand the diameter or allowed to expand naturally. However, with this method, the pipe end portion to be manually expanded is long, which places a heavy burden on the worker. The time required for manual expansion and natural expansion is also long.
In view of the above circumstances, the present invention aims to provide a finishing method in an expander pipe making method that can smoothly expand the pipe end portion of a rehabilitated pipe, reduce the workload of the worker in manually expanding the pipe after cutting and releasing, and shorten the time required for manual or natural expansion.

In order to solve the above problems, the present invention provides a method for rehabilitating an existing pipe, comprising the steps of: using a head-extrusion pipe making machine installed in a starting manhole connected to an existing pipe, helically winding a band-shaped member around the inner circumference of an annular outer periphery regulating body of the head-extrusion pipe making machine while fitting adjacent edge portions of the band-shaped member that are one revolution apart, thereby making a spiral rehabilitating pipe with a diameter smaller than the inner diameter of the existing pipe and forcing the rehabilitating pipe into the existing pipe; and after installing the rehabilitating pipe inside the existing pipe, gradually weakening the binding force between the adjacent edge portions along the winding direction from the tip side of the rehabilitating pipe in the pushing direction toward the head-extrusion side, sequentially feeding subsequent band portions of the band-shaped member that are continuous with the pipe end of the rehabilitating pipe on the head-extrusion side into the rehabilitating pipe by the head-extrusion pipe making machine, thereby expanding the circumferential length of the portion of the rehabilitating pipe where the binding force has been weakened and attaching it to the inner circumferential surface of the existing pipe,
The present invention is characterized in that, when the distance from the end of the cone section formed between the attached large diameter pipe section of the rehabilitated pipe and the small diameter pipe section of the rehabilitated pipe whose restraining force has not been weakened to the main extrusion pipe making machine becomes within a predetermined length, an expansion process is performed to expand the outer circumferential regulating body.

When the outer circumferential regulating body is expanded, the succeeding band portion newly sent to the head pipe making machine in the subsequent expansion process is wound spirally around the inner circumference of the expanded outer circumferential regulating body to make a pipe. Therefore, the new pipe diameter of the rehabilitated pipe is expanded. When the cone portion joins this, the small diameter end portion of the cone portion is expanded in diameter and the cone length is shortened. Since the cone angle can be kept constant, buckling at the small diameter end portion of the cone portion can be prevented even if the cone length is shortened. The large diameter end portion of the cone portion can be made to firmly stick to the inner circumferential surface of the existing pipe. This allows the pipe end portion on the head pipe side of the rehabilitated pipe to be expanded smoothly and satisfactorily.
The pipe end portion of the rehabilitating pipe is then cut between the pipe mouth of the existing pipe to the starting manhole and the main pipe making machine, and released from the main pipe making machine. The released pipe end portion of the rehabilitating pipe includes a cone portion having a short cone length.
The pipe end portion is manually twisted by an operator to manually expand the diameter or allowed to expand naturally. Since the cone length of the cone portion at the pipe end portion is short, the burden on the operator in manually expanding the diameter is reduced and the time required for manual expansion or natural expansion is shortened.

The outer circumferential restrictor is expanded in multiple stages. Preferably, a constraint weakening and expansion process is interposed between adjacent expansion processes. This prevents the outer circumferential restrictor from expanding significantly all at once, preventing the end of the rehabilitated pipe on the base side from coming off the outer circumferential restrictor.

In the pipe making machine used in the existing pipe rehabilitation method, the outer periphery restricting body is
An annular frame;
a plurality of guide rollers arranged in a circumferential direction of the annular frame and engaged with an outer peripheral groove of the belt-shaped member to guide the belt-shaped member;
It is preferable that the annular frame further comprises a diameter adjustment portion provided at one location in a circumferential direction of the annular frame and adapted to expand and contract along the circumferential direction.
The diameter of the annular frame and the outer periphery regulating body are expanded and contracted by the expansion and contraction of the diameter adjusting part. Preferably, the expanding operation of the diameter adjusting part and the process of expanding the diameter of the outer periphery regulating body are performed stepwise in a plurality of times, thereby preventing the outer periphery groove from coming out of engagement with the guide roller and maintaining the function of the guide roller to guide the belt-shaped member.

According to the present invention, in the expander pipe manufacturing method, the end portion of the rehabilitated pipe can be smoothly and satisfactorily expanded so that buckling does not occur and the end portion is firmly attached to the inner surface of the existing pipe. Furthermore, the burden on the worker in manually expanding the diameter can be reduced, and the time required for manual or natural expansion can be shortened.

FIG. 1 is an explanatory side view showing a method for rehabilitating an existing pipe according to an embodiment of the present invention, in a process for making a rehabilitating pipe. FIG. 2(a) is a front view taken along line IIa-IIa in FIG. 1, showing the end-extrusion pipe making machine used in the end-extrusion pipe making with the outer circumferential regulating body in a reduced diameter state. FIG. 2(b) is a front view taken along line IIb-IIb in FIG. 10, showing the end extrusion pipe making machine with the outer circumferential regulating body in an expanded diameter state. Fig. 3(a) is a cross-sectional view of the outer periphery regulating body taken along line IIIa-IIIa in Fig. 2(a), and Fig. 3(b) is a cross-sectional view of the outer periphery regulating body taken along line IIIb-IIIb in Fig. 2(a). Fig. 4(a) is a perspective cross-sectional view of the circular portion IVa in Fig. 1, showing the spiral joint of the rehabilitating pipe in the head-extrusion pipe-making process. Fig. 4(b) is a perspective cross-sectional view of the circular portion IVb in Fig. 5, showing the spiral joint of the rehabilitating pipe in the restraint weakening process. Fig. 4(c) is a perspective cross-sectional view of the circular portion IVc in Fig. 5, showing the spiral joint of the rehabilitating pipe in the expansion process. FIG. 5 is an explanatory side view showing the restraint weakening step and the expansion step before the finishing process in the existing pipe rehabilitation method. FIG. 6 is an explanatory side view showing the first diameter expansion step in the finishing process of the existing pipe rehabilitation method. FIG. 7 is an explanatory side view showing the existing pipe rehabilitation method in the constraint weakening step and the expansion step after the first diameter expansion step. FIG. 8 is an explanatory side view showing the second diameter expansion step of the existing pipe rehabilitation method. FIG. 9 is an explanatory side view showing the existing pipe rehabilitation method in the constraint weakening step and expansion step after the second (final) diameter expansion step. FIG. 10 is an explanatory side view showing the existing pipe rehabilitation method at a stage where the constraint weakening step and the expansion step have progressed after the final diameter expansion step. FIG. 11 is an explanatory side view showing the existing pipe rehabilitation method at a stage where the constraint weakening step and the expansion step have further progressed after the final diameter expansion step. FIG. 12 is an explanatory side view showing the existing pipe rehabilitation method at the end of the restraint weakening step and the expansion step. FIG. 13 is an explanatory side view showing the cutting and releasing process of the existing pipe rehabilitation method. FIG. 14 is an explanatory side view showing the existing pipe rehabilitation method at the completion stage of rehabilitation work.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
Fig. 1 shows how an aged existing pipe 1 is rehabilitated. The existing pipe 1 to be rehabilitated is, for example, a sewer pipe buried underground. Note that the object of rehabilitation in the present invention is not limited to sewer pipes, but may be a water supply pipe, an agricultural water pipe, a gas pipe, a hydroelectric power generation water pipe, a tunnel, etc. The existing pipe 1 is rehabilitated by lining the inner circumference of the aged existing pipe 1 with a rehabilitation pipe 3.

As shown in FIG. 1, the rehabilitation pipe 3 is a spiral pipe made of a band-shaped member 10. The material of the band-shaped member 10 is made of a synthetic resin such as polyvinyl chloride (PVC). As shown in FIG. 3 and FIG. 4, the band-shaped member 10 is a long band having a certain cross-sectional shape. The edge portions 13 and 14 on both sides in the band width direction of the band-shaped member 10 are formed with fitting portions having uneven cross sections. In detail, the edge portion 13 on one side is formed with two (multiple) first grooves 13a and second grooves 13b that open to the inner periphery side (upper side in FIG. 3). The edge portion 14 on the other side is formed with two (multiple) first convex strips 14a and second convex strips 14b that protrude to the outer periphery side (lower side in FIG. 3). The intermediate portion of the band-shaped member 10 in the band width direction is formed with multiple ribs 15 with a T-shaped cross section that protrude to the outer periphery side (lower side in FIG. 3). An outer circumferential groove 16 is formed between the ribs 15 or between the ribs 15 and the outer circumferential protruding portions 13d of the edge portion 13.
The cross-sectional shape of the belt-shaped member 10 is not limited to that shown in FIGS. 3 and 4 and can be modified as appropriate.

As shown in FIG. 4, the band-shaped member 10 in the rehabilitating pipe 3 is wound in a spiral shape, and adjacent edge portions 13, 14 that are one turn apart are fitted together in a concave-convex manner. More specifically, the first convex strip 14a is fitted into the first concave groove 13a, and the second convex strip 14b is fitted into the second concave groove 13b. As shown in FIG. 1, the rehabilitating pipe 3 has a spiral joint 12 formed from the edge portions 13, 14.

As shown in FIG. 1, the rehabilitating pipe 3 is manufactured by a pipe-making machine 20. As shown in FIG. 2(a), the pipe-making machine 20 includes an annular outer periphery regulating body 21, a strip-shaped member introduction section 22, and a pinch section 23. The outer periphery regulating body 21 includes an annular frame 24, a plurality of guide rollers 25, and a diameter adjustment section 26. The annular frame 24 includes a lower semicircular frame section 27 and a pair of upper quartercircular frame sections 28, and is formed into a spirally twisted ring shape. Both circumferential ends of the lower semicircular frame section 27 are connected to the upper quartercircular frame section 28 via side boxes 29. The lower ends of each upper quartercircular frame section 28 are rotatably connected to the upper ends of the side boxes 29.

As shown in FIG. 2(a), a diameter adjustment part 26 is provided at the upper end (one location in the circumferential direction) of the annular frame 24. The diameter adjustment part 26 is interposed between the upper ends of a pair of upper quarter-circular frame parts 28. The diameter adjustment part 26 includes a pair of arms 26a, an adjustment bolt 26b, and a hinge 26c. The upper ends of the pair of arms 26a are rotatably connected via the hinge 26c. The lower end of each arm 26a is rotatably connected to the upper end of the corresponding upper quarter-circular frame part 28. The adjustment bolt 26b is bridged across the middle part of the pair of arms 26a. The threaded part of the adjustment bolt 26b is screwed into a nut 26d provided on one arm 26a (the left one in FIG. 2(a)). The tip of the adjustment bolt 26b is engaged with the other arm 26a (the right one in FIG. 2(a)) so as to be rotatable and non-slidable. Alternatively, the adjustment bolt 26b may be slidably supported on one arm 26a (the left arm in FIG. 2(a)) and screwed into the nut of the other arm 26a (the right arm in FIG. 2(a)).

As shown in Figures 2(a) and 2(b), by adjusting the amount of screwing of the adjustment bolt 26b, the angle between the pair of arms 26a is increased or decreased, and the diameter adjustment part 26 is expanded or contracted along the circumferential direction of the annular frame 24. This causes the upper ends of the pair of upper quarter-circular frame parts 28 to approach or move apart, allowing the annular frame 24 to expand or contract in diameter.

As shown in FIG. 2(a), a plurality of guide rollers 25 are arranged in a line in the circumferential direction of the annular frame 24 so as to be freely rotatable. The rotation axis of each guide roller 25 is parallel to the axis of the annular frame 24. As shown in FIG. 3, one or more annular guides 25a are provided on the guide roller 25. As shown in FIG. 3(a) and FIG. 3(b), the mounting positions of the annular guides 25a on the guide rollers 25 adjacent in the circumferential direction of the annular frame 24 are shifted in the direction along the rotation axis of the guide roller 25 by the spiral pitch of the belt-shaped member 10. The guide roller 25 with the annular guide 25a arranged on one end side of the rotation axis (the right side in FIG. 3(a)) and the guide roller 25 with the annular guide 25a arranged on the other end side of the rotation axis (the left side in FIG. 3(b)) are alternately arranged in the circumferential direction of the annular frame 24.

Each annular guide 25a fits into and engages with the outer circumferential groove 16 of the strip-shaped member 10 at the starting end of the rehabilitation pipe 3. The guide rollers 25 guide the strip-shaped member 10 in a spiral shape.

As shown in FIG. 2(a), a pinch section 23 is provided in a side box 29 on one of the two sides of the annular frame 24 (the left side in FIG. 2(a)). The pinch section 23 includes a pair of pinch rollers 23a, 23b. The inner pinch roller 23a is disposed radially inward from the annular frame 24. The belt-shaped member introduction section 22 rises upward from the side box 29 including the pinch section 23. An inner roller 29a that presses the belt-shaped member 10 from the inner peripheral side is supported in the other side box 29 (the right side in FIG. 2(a)).

The rehabilitation pipe 3 is manufactured by the following expander pipe manufacturing method.
<Main extrusion pipe making process>
As shown in Figure 1, the head pipe making machine 20 is installed at the bottom of the starting manhole 4 connected to the pipe opening 1e on the starting side (left side in Figure 1) of the existing pipe 1. Since the starting manhole 4 is narrow, the distance from the head pipe making machine 20 to the pipe opening 1e is at most around 200 mm.
The strip-shaped material 10 is sequentially paid out from a pay-out drum 5 on the ground, inserted into a starting manhole 4, and supplied to a main pipe making machine 20, which produces the strip-shaped material 10 into a helical tube-shaped rehabilitated pipe 3.

2(a), the belt-shaped member 10 is introduced into the belt-shaped member introduction section 22. From there, the belt-shaped member 10 passes through the pinch section 23, is spirally wound around the inner circumference of the outer circumference regulating body 21, and is passed between the pinch rollers 23a and 23b in the pinch section 23 and tightly pinched. As a result, as shown in FIG. 4(a), the adjacent edge portions 13 and 14 of the spirally wound belt-shaped member 10, which are shifted from each other by one revolution, are joined by a concave-convex fit. The first convex strip 14a is fitted into the first groove 13a, and the second convex strip 14b is fitted into the second groove 13b. Preferably, the first groove 13a is filled with a slow-curing adhesive 17 before being fitted into the first convex strip 14a. The second groove 13b is preferably filled with a hot melt adhesive 18 when the belt-shaped member 10 is manufactured.

As shown in Figure 1, the rehabilitating pipe 3 thus produced is successively extruded from the original pipe extrusion machine 20 and pushed into the existing pipe 1. The tip 3f of the rehabilitating pipe 3 in the pushing direction (the right end in Figure 1) may be pulled by a winch or the like.

The circumference or diameter of the rehabilitated pipe 3 can be adjusted by restricting the rehabilitated pipe 3 from the outer periphery with the outer periphery restricting body 21. During pipe making at the original site, the diameter adjusting portion 26 of the outer periphery restricting body 21 is shortened and the annular frame 24 is made relatively small in diameter (Fig. 2(a)), so that the outer diameter (diameter of pipe made) of the rehabilitated pipe 3 is made smaller than the inner diameter of the existing pipe 1. This allows the rehabilitated pipe 3 to be reliably pushed into the existing pipe 1 even if there is an obstacle in the existing pipe 1 or the existing pipe 1 is slightly bent. Preferably, the outer diameter of the rehabilitated pipe 3 during pipe making at the original site is smaller than the inner diameter of the existing pipe 1 by about 50 mm to 200 mm.

<Wire embedding process>
As shown in Fig. 1, in parallel with the above-mentioned main extrusion pipe making process, a constraint weakening wire 41 is paid out from a pay-out reel 42. The constraint weakening wire 41 is inserted between the first convex strip 14a and the second convex strip 14b of the unmade pipe strip 10 (Fig. 3(a)). The constraint weakening wire 41 is then sandwiched between the edge portions 13, 14 by the concave-convex fit and embedded inside the spiral joint 12 (Fig. 4(a)).

As shown in FIG. 1, the tip end portion (pulling portion) 41b of the restraint weakening wire 41 is pulled out from the tip 3f of the rehabilitating pipe 3, folded back, and wound around a winding winch 43 on the ground through the internal space of the rehabilitating pipe 3 and the starting manhole 4. The pull-out folded portion 41c of the wire 41 is located at the tip 3f. The winding winch 43 is free to rotate during the original pipe making process.

As shown by the two-dot chain line in Figure 1, the pipe manufacturing is carried out until the rehabilitated pipe 3 reaches the pipe opening 1f on the access manhole 4B side of the existing pipe 1. This allows the rehabilitated pipe 3 to be installed over the entire area of the existing pipe 1. Preferably, the tip 3f of the rehabilitated pipe 3 is prevented from rotating relative to the pipe opening 1f by a rotation-stopping jig 6. At this stage, the rehabilitated pipe 3 is an unexpanded small-diameter pipe section 30 that is smaller in diameter than the existing pipe 1 over its entire area.

<Restraint Weakening Process>
After pipe manufacturing, as shown in FIG. 5, the take-up winch 43 takes up the take-up portion 41b of the restraint weakening wire 41, thereby pulling the restraint weakening wire 41 toward the base push side, i.e., the starting side (left side in FIG. 5). As a result, the portion 41a of the restraint weakening wire 41 embedded in the spiral joint 12 is successively pulled out from the tip side (right side in FIG. 5) of the rehabilitating pipe 3, and the pull-out fold-back portion 41c is moved to the base push side (left side in FIG. 5) along the winding direction of the spiral. At this time, as shown in FIG. 4(b), the root portion of the second convex strip 14b is cut by the pull-out fold-back portion 41c. As a result, the restraint force of the spiral joint 12 is successively weakened along the winding direction from the tip side of the rehabilitating pipe 3 toward the base push side (from right side to left side in FIG. 5).

<Expansion process>
As shown in Fig. 5, in parallel with the withdrawal of the constraint weakening wire 41, a trailing band portion 19 of the band-shaped member 10, which continues from the end 3e of the rehabilitating pipe 3 at the end, is fed into the rehabilitating pipe 3 by a head-pushing pipe making machine 20 (a pipe making machine for expansion) and assembled into the rehabilitating pipe 3. As a result, the end 3e of the rehabilitating pipe 3 is twisted, and the entire small diameter pipe section 30 including the end 3e is pushed toward the tip side (right side in Fig. 5) while rotating as a unit. Furthermore, in the portions 32, 33 where the constraint force of the spiral joint 12 is weakened on the tip side (right side in Fig. 5) of the small diameter pipe section 30 of the rehabilitating pipe 3, the edge portions 13, 14 slide against each other in the winding direction so as to be out of alignment with each other, and the circumferential length is expanded (diameter enlarged). As a result, the tip side (right side in FIG. 5 ) of the rehabilitating pipe 3 becomes the large diameter pipe section 33, which is larger in diameter than the small diameter pipe section 30, and is attached to the entire inner periphery of the existing pipe 1. Between the large diameter pipe section 33 and the small diameter pipe section 30 of the rehabilitating pipe 3, a truncated cone-shaped cone section 32 is formed, which expands in diameter from the unexpanded small diameter pipe section 30 toward the large diameter pipe section 33. The small diameter side end 32e of the cone section 32 is continuous with the small diameter pipe section 30, having the same diameter as the small diameter pipe section 30. The drawn-out folded-back section 41c is disposed at the small diameter side end 32e. The large diameter side end 32f (the end on the large diameter pipe section 33 side) of the cone section 32 is continuous with the large diameter pipe section 33, having the same diameter as the large diameter pipe section 33.

Through the constraint weakening process and the expansion process, the large diameter pipe section 33 gradually extends from the tip 3f of the rehabilitating pipe 3 toward the end push side (left side in FIG. 5), and the cone section 32 gradually moves toward the end push side (left side in FIG. 5). Preferably, the take-up speed of the constraint weakening wire 41 by the take-up winch 43 and the feed speed of the subsequent belt section 19 by the end push pipe making machine 20 are mutually adjusted so that the length _L32 of the cone section 35 along the pipe axis direction (hereinafter referred to as the "cone length") becomes an appropriate size. This makes it possible to prevent insufficient adhesion of the large diameter pipe section 33 and buckling at the small diameter end section 32e.

As shown in Figure 6, when the distance L from the end of the starting pipe port 1e side of the main extrusion pipe making machine 20 to the large diameter side end 32f of the cone section 32 (the starting side end of the large diameter pipe section 33) is within a predetermined length, the following finishing process is performed.
<Outer Circumferential Regulating Body Diameter Expansion (First Stage Diameter Expansion) Process>
The driving of the winding winch 43 and the main pipe making machine 20 is temporarily stopped, and the constraint weakening process and the expansion process are suspended. Then, the outer periphery restricting body 21 is expanded in diameter as shown by the arrow a1 in Fig. 6. More specifically, as shown in Fig. 2(b), the adjustment bolt 26b of the diameter adjustment portion 26 is screwed in a predetermined amount to expand the angle between the pair of arms 26a by a predetermined amount. This causes the pair of upper quarter-circular frame portions 28 to open by a predetermined amount, and the outer periphery restricting body 21 is expanded in diameter by Δφ1 (mm).

Preferably, the amount of diameter expansion Δφ1 is limited to about a fraction of the final target amount of diameter expansion Δφ0 (Δφ1 ≒ Δφ0/n, n is an integer of 2 or more). For example, Δφ1 is about several tens of mm, preferably Δφ1 is about 10 mm to 30 mm, and more preferably Δφ1 is about 25 mm. This prevents the annular guide 25a (Figure 3) from coming off the outer circumferential groove 16, and maintains the guiding function of the guide roller 25.

<Constraint Weakening and Expansion Re-execution Process>
Next, as shown in Fig. 7, the driving of the winding winch 43 and the main pipe making machine 20 is resumed, and the constraint weakening process and the expansion process are executed again. When the expansion process is executed again, the succeeding band portion 19 of the band-shaped member 10 is newly fed into the main pipe making machine 20 and is wound around the inner circumference of the outer circumferential regulating body 21 whose diameter has been expanded by Δφ1. As a result, the pipe diameter of the rehabilitated pipe section 34 newly manufactured by the main pipe making machine 20 in the rehabilitating pipe 3 becomes a size expanded by Δφ1 from the small diameter pipe section 30. Between the rehabilitating pipe section 34 and the small diameter pipe section 30, an inverted cone section 35 is formed, the diameter of which decreases from the rehabilitating pipe section 34 toward the small diameter pipe section 30.

As the end-pushing pipe making machine 20 is driven, the rehabilitated pipe section 34 extends in the pushing direction (to the right in FIG. 7), and the reverse cone section 35 is shifted in the pushing direction (to the right in FIG. 7). At the same time, the restraint weakening wire 41 is pulled up by the winding winch 43, shifting the cone section 32 to the end-pushing side (to the left in FIG. 7). Therefore, the small diameter pipe section 30 shortens at twice the speed of the expansion process before the finishing process.

<Outer periphery restrictor diameter expansion process (next stage diameter expansion)>
Next, the driving of the winding winch 43 and the main pipe making machine 20 is stopped again, and the constraint weakening process and the expansion process are paused again. Then, as shown by the arrow a2 in Fig. 8, the outer circumferential regulating body 21 is further expanded in diameter by the same operation as in the first stage. Preferably, the outer circumferential regulating body 21 is expanded in diameter by an amount Δφ2 that is approximately the same as the expansion amount Δφ1 in the first stage (Δφ2 ≈ Δφ1).

<Repeated process of weakening constraints and expanding>
As shown in Fig. 9, the take-up winch 43 and the head pipe making machine 20 are driven again to execute the constraint weakening process and the expansion process. As a result, the pipe diameter of the second stage rehabilitated pipe section 36 to be newly produced is expanded by Δφ2 from the first stage rehabilitated pipe section 34. A second stage inverted cone section 37 is formed between the rehabilitated pipe sections 34, 36, the diameter of which decreases from the rehabilitated pipe section 36 toward the rehabilitated pipe section 34.

As the end-pushing pipe making machine 20 is driven, the second-stage rehabilitated pipe section 36 extends in the pushing direction (to the right in FIG. 7), and the first-stage rehabilitated pipe section 34 and the inverted cone sections 35, 37 on both sides of it are moved in the pushing direction (to the right in FIG. 9). At the same time, the cone section 32 is moved to the end-pushing side (to the left in FIG. 9) by the take-up winch 43 pulling on the restraint weakening wire 41, and the small diameter pipe section 30 is shortened at twice the speed of the expansion process before the finishing process.

In this way, the diameter expansion process of the outer circumferential regulating body 21 is carried out stepwise in a plurality of times, and the constraint weakening and expansion process is interposed between adjacent diameter expansion processes, so that the pipe portion on the base pushing side of the rehabilitation pipe 3 is gradually expanded in diameter to the target diameter expansion amount Δφ0. This reliably prevents the annular guide 25a from coming off the outer circumferential groove 16 (FIG. 3), and reliably maintains the guiding function of the guide roller 25. In this embodiment, the target diameter expansion amount Δφ0 is reached by two diameter expansions (Δφ0=Δφ1+Δφ2), but the invention is not limited to this, and the diameter expansion process may be carried out stepwise three or more times.
The inner diameter of the outer circumferential regulating body 21 after the final diameter expansion step is smaller than the inner diameter of the existing pipe 1. The rehabilitated pipe section 36 expanded to the target diameter expansion amount Δφ0 has a smaller diameter than the large diameter pipe section 33.

As shown in Fig. 10, the cone section 32 is joined to the first stage inverted cone section 35 by the constraint weakening and expansion process after the final stage of the diameter expansion process. The small diameter tube section 30 (Fig. 9) between these cone sections 32, 35 disappears. Preferably, the cone length is maintained at a predetermined length _L32 until this point. In other words, the execution point of the first stage diameter expansion process (Fig. 6), i.e., the start point of the finishing process, is set so that the constraint weakening and expansion process can be performed without hindrance while maintaining the cone length at the predetermined length _L32 until the position where the cone section 32 joins the inverted cone section 35 (Fig. 10).

After that, when the restraint weakening and expansion process is further continued, the cone portion 32 is further moved to the end push side (left side in FIG. 10), and as shown by the imaginary line in FIG. 11, the reverse cone portion 35, the rehabilitating pipe portion 34, and the reverse cone portion 37 are successively absorbed by the cone portion 32. Furthermore, as shown by the solid line in FIG. 11, the small diameter side end portion 32e of the cone portion 32 reaches the rehabilitating pipe portion 36 of the target diameter (final stage). Accordingly, the small diameter side end portion 32e is gradually enlarged in diameter. The cone length L _32S becomes shorter (L _32S <L ₃₂ ). Hereinafter, the shortened cone portion 32 is referred to as the short cone portion 32S. Even though the short cone portion 32S is short, the small diameter side end portion 32e is enlarged in diameter, so that the cone angle can be maintained at a size almost the same as that of the cone portion 32 (FIGS. 5 to 10) before reaching the reverse cone portion 35. Therefore, it is possible to prevent buckling from occurring at the small diameter end 32e of the short cone portion 32S. The large diameter end 32f of the short cone portion 32S can be made to firmly stick to the inner circumferential surface of the existing pipe 1. This allows the expansion process to be carried out smoothly up to the vicinity of the pipe opening 1e.

Eventually, as shown in FIG. 12, the small diameter end 32e of the short cone section 32S emerges from the pipe mouth 1e into the starting manhole 4. Therefore, the drawn-out folded-back section 41c of the restraint weakening wire 41 is positioned between the original pipe making machine 20 and the pipe mouth 1e. At this point, the winding winch 43 and the original pipe making machine 20 are stopped, and the restraint weakening process and the expansion process are completed.

<Cutting and releasing process>
13, the rehabilitating pipe 3 is cut over its entire circumference at a cutting position P between the drawn-out folded-back portion 41c of the restraint weakening wire 41 and the pipe opening 1e, and the rehabilitating pipe 3 is released from the original pipe making machine 20. The released pipe end portion 31 of the rehabilitating pipe 3 is composed of a short cone portion 32S. The pipe end portion 31 is manually twisted to be expanded in diameter or allowed to expand in diameter naturally. Since the length of the pipe end portion 31 to be expanded in diameter, i.e., the cone length of the short cone portion 32S, is short, the burden on the worker in the manual expansion can be reduced. In addition, the time required for manual expansion or natural expansion can be shortened.

Then, as shown in FIG. 14, the pipe ends 3e and 3f of the rehabilitated pipe 3 are cut to be flush with the pipe openings 1e and 1f, respectively. Furthermore, the gap between the inner circumference of the pipe opening 1e and the outer circumference of the pipe end 3e, and the gap between the inner circumference of the pipe opening 1f and the outer circumference of the pipe end 3f are sealed with joint material 7. In this way, the rehabilitation work of the existing pipe 1 is completed.

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, during the finishing process, the second convex rib 14b of the subsequent band portion 19 of the band-shaped member 10 may be cut off in advance before or after introduction into the main pipe making machine 20. When the tip of the cut trace in the rehabilitating pipe 3 joins with the pull-out folded-back portion 41c, the restraint weakening process and the expansion process may be terminated, and a cutting and releasing process may be performed at a cutting position between the main pipe making machine 20 and the pipe mouth 1e.

The present invention can be applied, for example, to the rehabilitation of aging sewer pipes.

1 Existing pipe 1e Starting pipe opening 1f Arrival pipe opening 3 Rehabilitation pipe 3e Main push side pipe end 3f Pushing direction tip 4 Starting manhole 10 Belt-shaped member 12 Spiral joint 13 Edge portion 14 Edge portion 15 Rib 16 Outer peripheral groove 19 Subsequent belt portion 20 Main push pipe making machine 21 Outer peripheral regulating body 23 Pinch portion 24 Annular frame 25 Guide roller 26 Diameter adjustment portion 41 Restraint weakening wire 41c Pull-out turn-back portion 42 Payout reel 30 Small diameter pipe portion 32 Cone portion 32e Small diameter side end 32f Large diameter side end (end portion on the large diameter pipe portion side)
32S Short cone section 33 Large diameter tube section

Claims (3)

a rehabilitating pipe machine installed in a starting manhole connected to an existing pipe, a belt-shaped member is helically wound around the inner circumference of an annular outer periphery regulating body of the belt-shaped member while fitting adjacent edge portions of the belt-shaped member one circumference apart to produce a spiral rehabilitating pipe with a diameter smaller than the inner diameter of the existing pipe and the rehabilitating pipe is pushed into the existing pipe, the rehabilitating pipe is then installed inside the existing pipe, and the binding force between the adjacent edge portions is gradually weakened along the winding direction from the tip side of the rehabilitating pipe in the pushing direction toward the end side, while subsequent belt portions of the belt-shaped member that continue to the end side of the rehabilitating pipe are sequentially fed into the rehabilitating pipe by the end pipe machine, thereby expanding the circumferential length of the portion of the rehabilitating pipe where the binding force has been weakened and attaching it to the inner circumferential surface of the existing pipe;
A method for rehabilitating an existing pipe, characterized in that when the distance from the end of the cone section formed between the attached large diameter pipe section of the rehabilitated pipe and the small diameter pipe section of the rehabilitated pipe whose restraining force has not been weakened to the head extrusion pipe making machine becomes within a predetermined length, a diameter expansion process is performed to expand the outer circumferential regulating body. The method for rehabilitating an existing pipe according to claim 1, in which the process of expanding the outer periphery restrictor is carried out stepwise in multiple stages. 3. An end-extrusion pipe making machine used in the existing pipe rehabilitation method according to claim 1 or 2, wherein the outer periphery regulating body is
An annular frame;
a plurality of guide rollers arranged in a circumferential direction of the annular frame and engaged with an outer peripheral groove of the belt-shaped member to guide the belt-shaped member;
a diameter adjustment section provided at one location in the circumferential direction of the annular frame and adapted to expand and contract along the circumferential direction.

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