Pipe rehabilitation method

Abstract

To prevent, in the method of extending rehabilitation pipes, when cutting the rehabilitation pipe to separate the a pipe manufacturing machine, the disconnection of a spiral fitting by starting from the cut piece caused by cutting the spiral fitting bar.SOLUTION: After installing a spiral tubular rehabilitation pipe 3, made from a long, band-shaped member 10, inside a target rehabilitation pipe 1, the rehabilitation pipe 3 is further expanded by a pipe manufacturing machine 5 engaged with the first side pipe end 3d of the rehabilitation pipe 3. Then, the first side pipe portion 3d near the pipe manufacturing machine 5 on the rehabilitation pipe 3 is cut off to separate the pipe manufacturing machine 5 from the rehabilitation pipe 3. In the cutting process, the first side pipe portion 3d is cut to form a winding direction cut line 31, cutting it to a length greater than a predetermined length in the winding direction. Additionally, the spiral engagement strip 16 of the first side pipe portion 3d is cut in a transverse direction intersecting the winding direction cut line 31 to form a transverse cut line 32.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a pipe rehabilitation method in which a helical rehabilitating pipe is constructed inside a pipe to be rehabilitated by a so-called expansion (expander) pipe making method, and in particular to post-processing after the expansion pipe making process. [Background technology]

[0002] For example, an expansion pipe making method is known as one of the pipe rehabilitation methods for rehabilitating existing pipes such as deteriorated sewer pipes (see Patent Documents 1 to 3, etc.). In the expansion pipe making method, a push-type pipe making machine installed at the starting manhole is used to make a spiral-shaped rehabilitation pipe from a synthetic resin band-shaped member into the existing pipe while pushing it out so that the diameter of the rehabilitation pipe is smaller than the inside diameter of the existing pipe, thereby installing the rehabilitation pipe inside the existing pipe. Male and female mating parts are formed on both edges in the band width direction of the band-shaped member. During pipe making, the opposing male and female mating parts of the spirally wound band-shaped member are mated with each other with a restraint weakening wire sandwiched between them. This forms a spiral mating strip.

[0003] The tip side of the rehabilitated pipe, which has been made into a small diameter, i.e., the pipe end on the arrival side, is stopped from rotating in the arrival side manhole, and while the pipe is further advanced by the pipe making machine in the starting side manhole, the restraint weakening wire is pulled from the pipe end on the arrival side of the rehabilitated pipe toward the starting side. This weakens the restraining force of the spiral interlocking strip of the pulled-out portion, and the interlocking portions of the weakened portion slide against each other in the spiral winding direction, expanding the circumference (diameter expansion). As the restraint weakening wire is pulled-out, the expanded portion of the rehabilitated pipe extends from the pipe end on the arrival side toward the starting side. The expanded portion of the rehabilitated pipe is pressed tightly against the inner wall of the existing pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 04-232023 [Patent Document 2] JP 2021-115749 A [Patent Document 3] Patent Publication No. 2021-115750 Summary of the Invention [Problem to be solved by the invention]

[0005] In this type of expansion pipe manufacturing method, after expanding and manufacturing the rehabilitated pipe, it is necessary to separate and remove the pipe manufacturing machine from the rehabilitated pipe. In Patent Documents 2 and 3, the starting side pipe part of the rehabilitated pipe near the pipe manufacturing machine is cut in the starting side manhole for separation. When cutting the starting side pipe part in the circumferential direction of the pipe, it is inevitable to cut the helical interlocking rib at one point in the circumferential direction of the pipe. According to the inventor's knowledge, when the helical interlocking rib is cut, the cut piece including the cut line is deformed so as to be turned outward in the radial direction of the pipe, and the concave-convex interlocking of the helical interlocking rib of the rehabilitated pipe may come off in the extension direction of the helical interlocking rib starting from the cut piece. This is considered to be due to the stress acting on the band-shaped member constituting the rehabilitated pipe to expand. In consideration of the above circumstances, the present invention prevents the spiral interlocking rib from becoming disengaged, starting from a cut piece caused by the cutting of the spiral interlocking rib, when the rehabilitating pipe is cut to separate the pipe making machine in a rehabilitating pipe expansion pipe making method. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a pipe rehabilitation method which includes placing a helical rehabilitating pipe made of a long strip-shaped member in a pipe to be rehabilitated, gradually weakening a binding force of a helical fitting rib made of adjacent edges of the strip-shaped member in the rehabilitating pipe from a second side to a first side in the pipe axial direction of the rehabilitating pipe, while supplying a subsequent strip portion of an unmanufactured pipe of the strip-shaped member to the first side pipe end portion by a pipe making machine engaged with the first side pipe end portion of the rehabilitating pipe, thereby expanding the circumference of the weakened pipe portion of the rehabilitating pipe, and then cutting a first side pipe portion of the rehabilitating pipe near the pipe making machine to separate the pipe making machine from the rehabilitating pipe, the cutting step includes a winding direction cutting step of cutting the first side tube portion in a winding direction of the belt-shaped member by a predetermined length or more to form a winding direction cutting line having the predetermined length or more; a crossing step of cutting the helical fitting streak along the winding direction cutting line in the first side tube portion in a cross direction intersecting the winding direction cutting line; The present invention is characterized by comprising:

[0007] According to the pipe rehabilitation method, a slit in the belt-shaped member including a part of the helical interlocking rib is formed by the winding direction cutting line in the winding direction cutting step and the cross cutting line in the crossing step. The slit has an elongated shape of a predetermined length or more. Therefore, the force of the helical interlocking rib to maintain the concave-convex interlocking is greater than the force of the slit caused by the cutting of the helical interlocking rib to release the concave-convex interlocking of the helical interlocking rib and turn outward in the pipe radial direction. This makes it possible to prevent the slit in the belt-shaped member from turning outward in the pipe radial direction. Therefore, it is possible to prevent the concave-convex interlocking of the helical interlocking rib of the rehabilitation pipe from coming off in the extension direction of the helical interlocking rib starting from the slit caused by the cutting of the helical interlocking rib.

[0008] When the spiral interlocking strip has a plurality of concave-convex interlocking strips, the winding direction cutting step preferably includes cutting a portion of the spiral interlocking strip between two adjacent concave-convex interlocking strips. This reliably makes it possible to narrow the width of the slit of the belt-shaped member, thereby reliably making the force tending to turn the slit lower than the force with which the helical engagement ridge maintains the concave-convex engagement, and reliably preventing the helical engagement ridge from coming out of engagement.

[0009] Preferably, prior to the cutting step, the second interlocking ridge of the two interlocking ridges is cut, and in the crossing step, the first interlocking ridge of the two interlocking ridges is cut so as to cross, thereby shortening the crossing length. More preferably, in the weakening step, the mating convex rib of the second concave-convex mating rib is cut.

[0010] The predetermined length is set so as to prevent disengagement of the helical engagement groove. The predetermined length depends on the rigidity of the belt-shaped member, but is preferably 400 mm. This can reliably prevent the helical engagement groove from coming out of engagement. Depending on the rigidity of the belt-shaped member, the predetermined length may be set to be shorter than 400 mm, or may be set to be longer than 400 mm. Effect of the Invention

[0011] According to the present invention, in a pipe expansion construction method for rehabilitating pipes, when the rehabilitating pipe is cut to separate the pipe making machine, it is possible to prevent the helical interlocking groove from becoming disengaged, starting from a cut piece caused by the cutting of the helical interlocking groove. [Brief description of the drawings]

[0012] [Figure 1] Fig. 1(a) is a front view showing an existing pipe and a rehabilitated pipe undergoing rehabilitation work by a pipe rehabilitation method according to one embodiment of the present invention, during a process of making the rehabilitated pipe by pushing the pipe into the pipe. Fig. 1(b) is a front view showing the existing pipe and the rehabilitated pipe undergoing rehabilitation work, during a process of making the rehabilitated pipe by expanding the pipe. Fig. 1(c) is a front view showing the existing pipe and the rehabilitated pipe undergoing rehabilitation work, during a cutting process after the expanding pipe. [Diagram 2] Fig. 2(a) shows a strip-shaped member that becomes the rehabilitating pipe, and is a cross-sectional view taken along line IIa-IIa in Fig. 1(a). Fig. 2(b) is an enlarged cross-sectional view of the rehabilitating pipe at circular portion IIb in Fig. 1(a). Fig. 2(c) is an enlarged cross-sectional view of the rehabilitating pipe at circular portion IIc in Fig. 1(b). Fig. 2(d) is a cross-sectional view of the strip-shaped member taken along line IId-IId in Fig. 1(c). [Diagram 3] FIG. 3 is a plan view taken along line III-III in FIG. 1(c), illustrating a cutting step in the winding direction and a crossing step of the starting-side pipe portion of the rehabilitating pipe. [Figure 4] FIG. 4 is a front cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a plan view showing a second traversing step of the starting-side pipe portion. [Figure 6] FIG. 6 is a cross-sectional view of the starting-side pipe portion installed in the starting-side manhole, taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is a plan view showing an initial stage of the reversal process of the pipe making machine. [Figure 8] FIG. 8 is a plan view showing the end of the reversing step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. 1(a) to 1(c) show how to rehabilitate an aged existing pipe 1 (a pipe to be rehabilitated). The existing pipe 1 to be rehabilitated is 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. The existing pipe 1 is rehabilitated by lining the inner wall of the existing pipe 1 with a rehabilitation pipe 3.

[0014] As shown in FIG. 1(a), the rehabilitation pipe 3 is a spiral pipe made of a long strip-shaped member 10. The strip-shaped member 10 is made of a synthetic resin such as polyvinyl chloride (PVC). As shown in FIG. 2(a), two raised portions 11a and 11b are formed on an edge portion 11 on one side (left side in FIG. 2(a)) of the strip width direction (left and right in FIG. 2(a)). Each raised portion 11a and 11b has a fitting groove 13a and 13b that opens to the inner circumferential side (lower side in FIG. 2(a)). Therefore, two (multiple) fitting grooves 13a and 13b are formed on the edge portion 11. Between the raised portions 11a and 11b, a ridge-to-ridge groove 11c that opens to the outer circumferential side (upper side in FIG. 2(a)) is formed.

[0015] Two (multiple) mating protrusions 14a, 14b are formed side by side on the other edge 12 (right side in FIG. 2(a)) in the width direction of the belt-shaped member 10, protruding toward the outer periphery (upper side in FIG. 2(a)). A plurality of reinforcing protrusions 15, each having a hollow rectangular cross section, are formed in the middle of the belt-shaped member 10 in the width direction so as to protrude toward the outer periphery (upper side in FIG. 2(a)). The belt-shaped member 10 has higher rigidity than a typical belt-shaped member in which the reinforcing protrusions have, for example, a T-shaped cross section. The cross-sectional shape of the belt-shaped member 10 can be modified as appropriate.

[0016] As shown in FIG. 2(b), in the rehabilitating pipe 3, adjacent edge portions 11, 12 of the spirally wound belt-shaped member 10, which are offset from one another, are engaged with each other to form a helical engagement rib 16. The helical engagement rib 16 includes two (multiple) helical engagement ribs 16a, 16b, and extends helically over the entire area of ​​the rehabilitating pipe 3. The first helical engagement rib 16a is formed by the helical engagement of the engagement groove 13a and the engagement protrusion rib 14a. The second helical engagement rib 16b is formed by the helical engagement of the engagement groove 13b and the engagement protrusion rib 14b. As shown in FIG. 2(c), the engagement protrusion rib 14b is cut during the expansion pipe manufacturing process of the rehabilitating pipe 3.

[0017] The existing pipe 1 is rehabilitated by the following expansion pipe construction method. As shown in FIG. 1(a), a starting manhole 4 connected to a pipe mouth 1e on the starting side (first side) of an existing pipe 1 is provided with a push-type pipe making machine 5.

[0018] <Main extrusion pipe making process> The strip-shaped member 10 is introduced from the drum 6 on the ground through the starting manhole 4 into the pipe making machine 5. As the pipe making machine 5 rotates in the normal direction, the strip-shaped member 10 is wound spirally, and the mating grooves 13a and mating ridges 14a of adjacent edges 11, 12 that are one turn apart are mated with each other, and the mating grooves 13b and mating ridges 14b are mated with each other (FIG. 2(b)). In this way, a rehabilitated pipe 3 is made from the strip-shaped member 10.

[0019] As shown in Fig. 2(a), when the recesses and protrusions are fitted together, the fitting groove 13a is filled with a water-stopping material 41 made of a slow-hardening adhesive from a nozzle 40. The time required for the water-stopping material 41 to harden is several days to several weeks or more. It should be noted that hot melt adhesive 42 is applied to fitting groove 13b when belt-shaped member 10 is manufactured.

[0020] 1(a), a constraint weakening wire 20 is paid out from a payout roll 21 on the ground. As shown in FIGS. 2(a) and 2(b), the constraint weakening wire 20 is sandwiched between the edges 11, 12 when the recesses and protrusions are fitted together.

[0021] As shown in Figure 1(a), the rehabilitated pipe 3 produced by the pipe producing machine 5 has a smaller diameter than the inside diameter of the existing pipe 1. As indicated by arrow a in the figure, the pipe producing machine 5 rotates while producing the rehabilitated pipe 3 by forward drive, and pushes it into the existing pipe 1. In this way, the rehabilitated pipe 3 is installed inside the existing pipe 1. The pipe end 3e on the starting side (first side) of the rehabilitating pipe 3 is engaged with the pipe producing machine 5.

[0022] <Expanded pipe manufacturing process> As shown in FIG. 1(a), when the pipe end 3f on the tip side (reach side) in the extrusion direction of the rehabilitation pipe 3 reaches the reach side manhole 4B, the pipe end 3f is prevented from rotating by an anti-rotation means 7 such as a rod. Next, while the pipe is further produced by the pipe producing machine 5, the restraint weakening wire 20 is successively taken up by the take-up winch 22 from the pipe end 3f on the arrival side (second side) of the rehabilitating pipe 3 toward the starting side. As shown in Fig. 2(c), the fitting convex rib 14b is cut from its base by the restraint weakening wire 20 during the take-up.

[0023] As shown in Fig. 1(b), this causes the binding force of the helical fitting rib 16 to be gradually weakened from the pipe end 3f of the rehabilitating pipe 3 toward the starting side (first side, right side in Fig. 1). Furthermore, as the pipe making machine 5 is driven to supply the subsequent belt portion 19 of the unmade pipe of the belt-shaped member 10 to the pipe end 3e, the unweakened small diameter pipe portion 3b of the rehabilitating pipe 3 is twisted, and the edges 11, 12 constituting the helical fitting rib 16 of the weakened pipe portion 3a of the rehabilitating pipe 3 slide against each other in the helical winding direction, expanding the circumferential length of the pipe portion 3a. As a result, the pipe portion 3a is attached to the inner wall of the existing pipe 1.

[0024] As shown in FIG. 1(b), the expanded large-diameter tube portion 3a is gradually extended from the arrival side (second side) toward the departure side (first side). A cone portion 3c is formed between the large diameter tube portion 3a and the small diameter tube portion 3b. As the tube portion 3a expands, the cone portion 3c moves to the starting side (first side).

[0025] As shown in Figures 1(b) and 2(d), after the cone portion 3c has been moved close to the starting pipe port 1e, the mating ridge 14b of the trailing band portion 19 before pipe production is pre-cut by the cutting jig 8. The trailing band portion 19 is then subjected to pipe production. Eventually, the portion of the mating ridge 14b cut by the restraint weakening wire 20 and the portion of the mating ridge 14b pre-cut by the cutting jig 8 join together near the starting pipe port 1e.

[0026] Therefore, prior to a cutting step described later, the engaging convex rib 14b of one of the two adjacent concave-convex engaging ribs 16a, 16b of the spiral engaging rib 16 is cut over the entire area of ​​the rehabilitating pipe 3. This allows the rehabilitating pipe 3 to be smoothly expanded close to the pipe making machine 5 and brought into close contact with the inner wall of the existing pipe 1, as shown in FIG. 1(c). In this way, the expansion pipe making process is completed.

[0027] <Separation process> As shown in Fig. 1(c), thereafter, a starting-side pipe portion 3d (first side pipe portion) of the rehabilitating pipe 3 near the pipe making machine 5 is cut, and the pipe making machine 5 is separated from the rehabilitating pipe 3. Preferably, the starting-side pipe portion 3d is disposed between the starting-side pipe opening 1e and the pipe making machine 5, and appears in the starting-side manhole 4. A cutting tool 9 such as a saber saw is used to cut the starting-side pipe portion 3d.

[0028] The cutting step includes a winding direction cutting step, a traversing step, and a second traversing step. <Winding direction cutting process> 3, in the winding direction cutting step, one winding portion 3dc of the upper half 3da of the starting-side tube portion 3d is cut to a predetermined length or more along the winding direction of the belt-shaped member 10. As a result, a winding direction cutting line 31 having a predetermined length or more is formed in the upper half 3da of the starting-side tube portion 3d. The length of the winding direction cutting line 31 depends on the rigidity of the belt-shaped member 10, but is preferably L=400 mm or more. The lower half 3db of the starting side pipe portion 3d is fitted into the semicircular concave surface 51 of the invert 50 of the starting side manhole 4.

[0029] Preferably, the winding direction cutting line 31 extends along the helical interlocking ridge 16 of the winding portion 3dc. More preferably, the helical interlocking ridge 16 is cut at a portion between two adjacent concave-convex interlocking ridges 16a, 16b, as shown in Fig. 4. This positions the winding direction cutting line 31 in the inter-ridge groove 11c.

[0030] The winding direction cutting line 31 may be formed at a position (e.g., reinforcing protrusion 15) that is deviated from the helical interlocking rib 16 in the winding portion 3dc. The winding direction cutting line 31 may be slightly oblique to the extending direction (helical rib direction) of the helical interlocking rib 16 as long as it is along the winding direction of the belt-shaped member 10, and may extend in the circumferential direction of the starting-side pipe portion 3d. Furthermore, the winding direction cutting line 31 does not need to be linear, and may extend along the winding direction when viewed macroscopically, and may be irregularly bent when viewed enlarged.

[0031] <Cross-cutting process> As shown in Fig. 3, the crossing step is then performed. By the crossing step, a cross cutting line 32 is formed in the upper half 3da of the starting-side pipe portion 3d. Note that the timing of performing the crossing step is not limited to after the winding direction cutting step, but may be before the winding direction cutting step or during the winding direction cutting step. In the crossing step, the helical interlocking ridge 16 along the winding direction cutting line 31 is cut so as to cross in a cross direction intersecting with the winding direction. Therefore, a cross cutting line 32 is formed so as to cross the helical interlocking ridge 16. As a result, the first concave-convex interlocking ridge 16a of the helical interlocking ridge 16, and thus the protuberance 11a, are cut in the cross direction. In addition, the engaging convex rib 14b of the second concave-convex engaging rib 16b in the spiral engaging rib 16 has already been cut over the entire area of ​​the rehabilitated pipe 3 during the weakening process in the expansion pipe making process (FIGS. 2(c) and 2(d)).

[0032] Preferably, in the crossing step, the band-shaped member 10a constituting the wound portion 3dc is cut so as to connect the edge 11e (edge ​​1) on the raised portion 11a side to one end (lower end in FIG. 3) of the winding direction cutting line 31. The cross cutting line 32 intersects with one end of the winding direction cutting line 31 and reaches the edge 11e on the raised portion 11a side of the wound portion 3dc. The cross cutting line 32 is sufficiently shorter than the winding direction cutting line 31. The transverse cutting line 32 may extend in the tube axial direction or may be slightly oblique to the tube axial direction.

[0033] As shown in Fig. 3, a slit 11ae is formed in the protruding portion 11a of the winding portion 3dc by a winding direction cutting line 31 and a transverse cutting line 32. The slit 11ae has an elongated shape having a predetermined length or more (preferably L = 400 mm or more). Therefore, a deformation force F 11ae This reduces the deformation force F 11ae However, the force F of the groove-projection engagement strip 16a to maintain the engagement is 16a can be made smaller than (F 11ae <F 16a ).

[0034] This prevents the notch 11ae from turning outward in the pipe radial direction, thereby preventing disengagement of the helical fitting ridge 16. Specifically, the protrusion 11a of the notch 11ae can be prevented from coming off the fitting protrusion ridge 14a and turning outward in the pipe radial direction, thereby preventing disengagement of the helical fitting ridge 16 from proceeding in the helical ridge direction starting from the notch 11ae. During the cutting process, the water-stopping material 41 made of a slow-hardening adhesive is not yet hardened.

[0035] <Second crossing process> As shown in Fig. 5, the winding portion 3dc is further cut substantially along the band width direction so as to connect the end portion of the winding direction cutting line 31 opposite to the intersection with the transverse cutting line 32 (upper side in Fig. 5) to the other edge portion 12 of the band-shaped member 10 in the winding portion 3dc. As a result, a band width direction cutting line 33 is formed in the upper half portion 3da of the starting-side pipe portion 3d. The band width direction cutting line 33 intersects with the winding direction cutting line 31 and reaches the other edge 12e of the band-shaped member 10 in the winding portion 3dc. The order of forming the cutting lines 31, 32, and 33 may be changed as appropriate. The transverse cutting line 32, the winding direction cutting line 31, and the strip width direction cutting line 33 may be formed in a single cutting operation in a single stroke.

[0036] The three cutting lines 31, 32, 33 are connected at angles to each other. These cutting lines 31, 32, 33 form the band dividing line 30. As a result, the band-shaped member 10a constituting the winding portion 3dc of the starting-side pipe portion 3d is cut across the entire width in the band width direction. That is, the band-shaped member 10a is cut from one edge 11e to the other edge 12e in the band width direction. Therefore, the band-shaped member 10 constituting the rehabilitating pipe 3 is divided by the band dividing line 30 along the band length direction (winding direction) into an end-side pipe portion 3g from the pipe end portion 3e to the band dividing line 30 and a pipe portion 3h on the existing pipe 1 side from the band dividing line 30. Preferably, the cut piece 11ae is included in the pipe portion 3h on the side of the pipe to be rehabilitated. As shown in FIG. 6, the band dividing line 30 is disposed only in the upper half 3da of the starting side pipe portion 3d, and does not extend to the lower half 3db of the starting side pipe portion 3d.

[0037] <Reverse process> As shown in Fig. 7, the pipe making machine 5 is then driven in the reverse direction. That is, as shown by arrow b in Fig. 7, it is driven to rotate in the opposite direction to the rotation direction in the original pipe making process and the expansion pipe making process. As a result, the end side pipe section 3g is rotated in the reverse direction so as to be wound up toward the subsequent band section 19. On the other hand, the pipe section 3h on the pipe to be rehabilitated is not wound up because it is cut off from the pipe making machine 5 by the band dividing line 30. As a result, the fitting groove 13a and the fitting convex rib 14a which constitute the concave-convex fitting rib 16a (see Fig. 4) of the spiral fitting rib 16 spanning both pipe sections 3g, 3h slide against each other in the spiral rib direction. During the reversal step, the water-stopping material 41 made of a slow-hardening adhesive is not yet hardened.

[0038] As shown in Figure 8, the fitting grooves 13a and fitting protrusions 14a eventually disengage, separating the pipe sections 3g, 3h. This separates the pipe making machine 5 from the rehabilitating pipe 3 inside the existing pipe 1. After separation, the pipe making machine 5 and the end pipe section 3g engaged with the pipe making machine 5 are removed from the starting manhole 4. The pipe making machine 5 may be disassembled into a size that can be carried out from the above-ground entrance of the starting manhole 4 before being carried out.

[0039] According to this separation method, it is only necessary to cut the wound portion 3dc of the upper half 3da of the starting-side pipe portion 3d, and there is no need to cut the entire circumference of the starting-side pipe portion 3d in the pipe circumferential direction. Therefore, there is no need to cut the lower half 3db of the starting-side pipe portion 3d. Even if the lower half 3db of the starting-side pipe portion 3d is close to or in contact with the invert 50 at the bottom of the starting-side manhole 4, or even if it is fitted into the semicircular concave surface 51 of the invert 50, the cutting work is not hindered. This makes it possible to easily perform the separation operation of the pipe making machine 5.

[0040] 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 step of pre-cutting the fitting protrusion 14b of the trailing band portion 19 by the cutting jig 8 after the cone portion 3c has been moved close to the starting-side pipe port 1e may be omitted. [Industrial Applicability]

[0041] The present invention is applicable to, for example, rehabilitation work for deteriorated sewer pipes. [Explanation of symbols]

[0042] 1. Existing pipes (pipes to be rehabilitated) 1e Starting pipe port (first side pipe port) 3 Rehabilitation pipe 3d Starting pipe section (first pipe section) 3da upper half 3db lower half 3dc 1 winding part 3e Starting pipe end (first pipe end) 3f End of the pipe on the arrival side (end of the pipe on the second side) 3g End tube part 3h Side pipe section of the pipe to be rehabilitated 4. Starting manhole 5 Pipe making machine 9 cutting tools 10 Belt-shaped member 10a: Belt-shaped member constituting the winding portion 11 One edge 11a Ridge 11ae Cut piece 11b Ridge 11c Interridge groove Edge of 11e 1 12 Other edge 12e The other edge 13a,13b Fitting groove 14a, 14b Fitting protrusion 16 Spiral mating groove 16a First concave-convex mating groove 16b Second concave-convex mating groove 19 Trailing belt 20 Wire for weakening restraints 30 Stripped wire 31 Winding direction cutting line 32 Transverse cutting line 33 Band width direction cutting line 50 Invert 51 Semicircular concave surface

Claims

1. A pipe rehabilitation method comprising: placing a helical rehabilitating pipe made of a long strip-shaped member in a pipe to be rehabilitated; gradually weakening a binding force of a helical fitting rib made of adjacent edges of the strip-shaped member in the rehabilitating pipe from a second side to a first side in the pipe axial direction of the rehabilitating pipe from the second side to the first side; supplying a subsequent strip of unmanufactured pipe of the strip-shaped member to the first side pipe end by a pipe making machine engaged with the first side pipe end of the rehabilitating pipe, thereby expanding the circumference of the weakened pipe portion of the rehabilitating pipe; and then cutting a first side pipe portion of the rehabilitating pipe near the pipe making machine to separate the pipe making machine from the rehabilitating pipe, the cutting step includes a winding direction cutting step of cutting the first side tube portion in a winding direction of the belt-shaped member by a predetermined length or more to form a winding direction cut line having the predetermined length or more; a crossing step of cutting the helical fitting streak along the winding direction cutting line in the first side tube portion in a cross direction intersecting the winding direction cutting line; A pipe rehabilitation method comprising the steps of:

2. The helical interlocking groove has a plurality of concave-convex interlocking grooves, 2. The pipe rehabilitation method according to claim 1, wherein the winding direction cutting step cuts a portion of the spiral engagement strip between two adjacent concave-convex engagement strips.

3. Prior to the cutting step, the engaging convex rib of the second engaging convex rib of the two ribs is cut, The pipe rehabilitation method according to claim 2 , wherein in the crossing step, a first concave-convex engagement line of the two lines is cut so as to cross the first concave-convex engagement line.

4. A pipe rehabilitation method according to any one of claims 1 to 3, wherein the predetermined length is 400 mm.

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