Pipe rehabilitation method

Abstract

To prevent disengagement of a helical fitting thread even if a belt-like member has high rigidity when cutting a rehabilitating pipe for separating a pipe manufacturing machine in an expansion pipe making method for the rehabilitating pipe.SOLUTION: After a helical rehabilitating pipe 3 made of a long belt-like member 10 is placed inside a pipe to be rehabilitated 1, the rehabilitating pipe 3 is further expanded and manufactured by a pipe manufacturing machine 5 engaged with a first pipe end part 3d of the rehabilitating pipe 3. Then, multiple incisions 31, 32 are formed in an outer surface 3h of a predetermined winding part 17 of a first side pipe part 3d of the rehabilitating pipe 3 near the pipe manufacturing machine 5. The incisions 31, 32 each extend in a direction intersecting a winding direction of the belt-like member 10 and are spaced apart from each other in the winding direction. Next, the belt-like member 10 in the first side pipe part 3d is cut between the predetermined winding part 17 and a subsequent winding part 18 to form a strip-severed line 50. Next, the pipe manufacturing machine 5 is driven in a reverse direction to wind up the subsequent winding part 18.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a pipe rehabilitation method for constructing a spiral-shaped rehabilitation pipe 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, the expansion pipe manufacturing method is known as one of the pipe rehabilitation methods for rehabilitating existing pipes such as aging sewer pipes (see Patent Documents 1 to 3, etc.). In the expansion pipe manufacturing method, a push-type pipe manufacturing machine installed in the starting manhole is used to push out a spiral-shaped rehabilitation pipe from a band-shaped member made of synthetic resin into the existing pipe while manufacturing a pipe with a diameter smaller than the inner diameter of the existing pipe, thereby installing the rehabilitation pipe inside the existing pipe. Male and female mating portions are formed on both edges in the band width direction of the band-shaped member. During pipe manufacturing, the opposing male and female mating portions 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 groove.

[0003] The end of the rehabilitating pipe on the arrival side, which has been produced to a smaller diameter, is secured to the manhole on the arrival side, and the pipe is further advanced by the pipe-making machine in the manhole on the departure side, while the restraint weakening wire is pulled from the end of the rehabilitating pipe on the arrival side toward the departure side. This weakens the restraining force of the helical interlocking grooves in 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). As the restraint weakening wire is pulled-out, the expanded portion of the rehabilitating pipe extends from the end of the pipe on the arrival side toward the departure side. The expanded portion of the rehabilitating pipe is tightly attached to 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] Japanese Patent Publication No. 2021-115749 [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, the pipe manufacturing machine must be separated and removed from the rehabilitated pipe. In Patent Documents 2 and 3, the starting-side pipe section of the rehabilitated pipe near the pipe manufacturing machine is cut in the starting-side manhole for separation. When cutting the starting-side pipe section circumferentially, it is inevitable to cut the helical interlocking rib at one location circumferentially. According to the inventor's knowledge, when the helical interlocking rib is cut, the cut edge on the side that remains as part of the rehabilitated pipe across the cutting line deforms by curling outward in the pipe diameter direction, which can cause the concave-convex interlocking of the helical interlocking rib of the rehabilitated pipe to disengage from the cut edge in the extension direction of the helical interlocking rib. This is thought to be due to elastic stress acting on the strip-shaped member that constitutes the rehabilitated pipe, which tends to expand. In particular, if the strip-shaped member has high rigidity, the cut edge is likely to deform radially outward, resulting in the helical interlocking rib becoming disengaged. In view of the above circumstances, the present invention aims to reliably prevent the helical interlocking strip from coming loose when cutting the rehabilitated pipe to separate the pipe making machine in an expansion pipe making method for rehabilitated pipes, even if the rigidity of the strip-shaped member is high. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a pipe rehabilitation method that includes installing a helical rehabilitating pipe, which is formed by helically winding a long strip-shaped member, inside a pipe to be rehabilitated, and then gradually weakening the binding force of the helical fitting ribs, which are formed by adjacent edges of the strip-shaped member that are offset by one turn, in the axial direction of the rehabilitating pipe from the second side to the first side of the rehabilitating pipe, while supplying a subsequent strip portion of unmanufactured pipe of the strip-shaped member to the first side end using a pipe manufacturing machine engaged with the first side end of the rehabilitating pipe, thereby expanding the circumferential length of the weakened pipe portion of the rehabilitating pipe, and then cutting a first side pipe portion of the rehabilitating pipe near the pipe manufacturing machine to separate the pipe manufacturing machine from the rehabilitating pipe, Prior to the cutting step, a plurality of notches are formed in the outer peripheral surface of a predetermined wound portion of the belt-shaped member in the first side tube portion, the notches extending in a direction intersecting the winding direction of the belt-shaped member and spaced apart from one another in the winding direction; Next, in the cutting step, the belt-shaped member in the first side tube portion is cut between the predetermined winding portion and a subsequent winding portion on the subsequent belt portion side in the winding direction, i.e., on the subsequent side, from the predetermined winding portion to form a band dividing line that divides the predetermined winding portion and the subsequent winding portion, Next, in the separating step, the pipe making machine is driven in a reverse direction from that during the supplying step to wind the subsequent wound portion onto the subsequent side.

[0007] According to this pipe rehabilitation method, the incision forming process can weaken the elastic stress that causes the predetermined turn portion of the first side pipe section of the rehabilitated pipe to bulge outward in the pipe diameter direction. Therefore, the predetermined turn portion can be prevented from deforming in a manner that causes it to curl outward in the pipe diameter direction during the subsequent cutting process. Even if the strip-shaped member is highly rigid, by sufficiently weakening the elastic stress through the incisions, it is possible to reliably prevent the predetermined turn portion from deforming in a manner that causes it to bounce outward in the pipe diameter direction. This prevents the helical engagement thread from becoming disengaged, starting from the cut portion of the helical engagement thread in the predetermined turn portion. The subsequent reverse drive process winds the subsequent wound portion of the strip across the dividing line, while the predetermined wound portion remains as part of the rehabilitated pipe. This separates the rehabilitated pipe from the pipe making machine, allowing the pipe making machine to be removed.

[0008] Preferably, the spacing between the notches in the cut-out strip portion along the edge of the trailing side and the second side of the specified winding portion in the spiral mating strip is smaller than the spacing between the notches on the side opposite the trailing side in the winding direction from the cut-out strip portion. This allows the cutting to be performed after the elastic stress in the cut-out strip portion is sufficiently reduced, thereby reliably preventing the cut-out strip portion from being deformed so as to be turned outward in the radial direction of the pipe, and as a result, reliably preventing the helical fitting strip from coming loose.

[0009] Preferably, in the cutting step, the trailing end of the cut-out strip portion is cut transversely, and the first side portion of the cut-out strip portion is cut longitudinally along the winding direction. By cutting the end of the cut-out strip portion at the beginning of the cutting process, the male and female mating portions of the spiral mating strip slide off each other in the winding direction during subsequent cutting, making it less likely that disengagement will occur.

[0010] Preferably, in the cutting step, the first side tube portion is cut so as to move toward the opposite side of the winding direction as it approaches a first side stripe portion that is one turn away from the cut-out stripe portion of the spiral mating strip toward the first side. This cuts the first side pipe section at a generally oblique angle relative to the pipe axis or circumferential direction. The width of the remaining predetermined winding section, which remains as a rehabilitated pipe, decreases toward the rear of the winding direction, sufficiently weakening the radially outward elastic force of the predetermined winding section. This reliably prevents the helical engagement strip from coming loose.

[0011] Preferably, the belt-shaped member has a plurality of outer peripheral convex stripes and outer peripheral grooves extending in the belt length direction and alternately formed in the belt width direction, The first side pipe portion is cut so that the band dividing line forms a step shape including a groove longitudinal cutting line that cuts vertically through the outer peripheral groove and a convex strip crossing line that crosses the outer peripheral convex strip. This facilitates cutting. In particular, since the pipe thickness in the outer circumferential groove is small, it is easy to form a longitudinal groove cut line. Furthermore, the width of the predetermined wound portion that remains as the rehabilitated pipe can be gradually reduced toward the succeeding end in the winding direction, thereby gradually weakening the elastic force acting radially outward in the pipe direction.

[0012] Preferably, the depth of the cut is such that it does not reach the inner peripheral surface of the first side pipe portion. This makes it easier to form the incisions.

[0013] Preferably, the belt-shaped member has a flat belt portion that defines the inner peripheral surface, and a reinforcing outer peripheral protrusion that protrudes from the flat belt portion to the outer peripheral side and extends in the belt length direction, The depth of the cut is equal to or less than the protruding height of the reinforcing outer peripheral ridge. There is no need to make cuts all the way to the flat band portion, making it easier to form cuts.

[0014] Preferably, the depth of the cut is between one half and three quarters of the pipe thickness of the rehabilitating pipe, and more preferably about two thirds. If the depth of the cut is too small, the elastic force of the first side pipe portion toward the outside in the pipe diameter direction cannot be weakened sufficiently, and there is a risk that the cut edge portion will turn up. If the cutting depth is too great, it becomes difficult to form the cutting.

[0015] Preferably, the predetermined winding portion is set on an upper peripheral side portion of the first side tube portion. This allows the first side tube portion to be easily cut and incised from above, eliminating the need to incise or cut the lower peripheral portion of the first side tube portion. [Effects of the Invention]

[0016] According to the present invention, in a method for expanding and manufacturing a rehabilitated pipe, when the rehabilitated pipe is cut to separate the pipe manufacturing machine, even if the rigidity of the strip-shaped member is high, it is possible to reliably prevent the spiral mating strip from coming loose. [Brief explanation of the drawings]

[0017] [Figure 1] Fig. 1(a) is a front view showing an existing pipe and a rehabilitating pipe undergoing rehabilitation work using a pipe rehabilitation method according to one embodiment of the present invention, during the process of making the rehabilitating pipe by forcing the pipe to be rehabilitated. Fig. 1(b) is a front view showing the existing pipe and the rehabilitating pipe undergoing rehabilitation work, during the process of making the rehabilitating pipe by expanding the pipe. Fig. 1(c) is a front view showing the existing pipe and the rehabilitating pipe undergoing rehabilitation work, during the cutting process after the expanding pipe. [Figure 2]Fig. 2(a) shows the strip-shaped member that will become 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 the circular portion IIb in Fig. 1(a). Fig. 2(c) is an enlarged cross-sectional view of the rehabilitating pipe at the 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(b). [Figure 3] FIG. 3 is a plan view taken along line III-III in FIG. 1(c), showing a predetermined winding portion that is imaginarily set on the starting-side pipe portion (first side pipe portion) of the rehabilitation pipe. [Figure 4] FIG. 4 is a plan view showing the starting-side pipe portion in a step of cutting into a predetermined wound portion. [Figure 5] Fig. 5(a) is a cross-sectional view of the starting-side pipe portion taken along line Va-Va in Fig. 4. Fig. 5(b) is a cross-sectional view of the starting-side pipe portion taken along line Vb-Vb in Fig. 6. Fig. 5(c) is a cross-sectional view of the starting-side pipe portion taken along line Vc-Vc in Fig. 6. [Figure 6] FIG. 6 is a plan view showing the starting-side pipe portion in a cutting step. [Figure 7] FIG. 7 is a plan view showing the starting-side pipe portion in the reverse driving step. [Figure 8] FIG. 8 is a plan view of the starting pipe portion after the pipe making machine has been separated. [Figure 9] FIG. 9 shows the second embodiment of the present invention and is a plan view of a starting-side pipe portion (first side pipe portion) during a cutting step. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. <First embodiment (FIGS. 1 to 8)> 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 sewer pipe buried underground, but the present invention is not limited to this and may also 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.

[0019] As shown in FIG. 1(a), the rehabilitating pipe 3 is a spiral pipe made of a long strip-shaped member 10. The material of the strip-shaped member 10 is made of a synthetic resin such as polyvinyl chloride (PVC). As shown in FIG. 2(a), the strip-shaped member 10 includes a flat band portion 11, a plurality of reinforcing outer peripheral ridges 12, and male and female mating portions 13, 14. The flat band portion 11 is formed in the shape of a relatively thick flat band. As shown in FIG. 2(b), the flat band portion 11 defines the inner peripheral surface 3g of the rehabilitating pipe 3.

[0020] As shown in Figure 2(a), the outer peripheral ridges 12 are formed, for example, with a hollow rectangular cross section, and protrude from the flat belt portion 11 toward the outer periphery (upward in Figure 2(a)) and extend in the belt length direction of the belt-shaped member 10 (direction perpendicular to the paper surface in Figure 2(a)). Multiple outer peripheral ridges 12 are lined up in the belt width direction (left-right direction in Figure 2(a)). An outer peripheral groove 15 is formed between adjacent outer peripheral ridges 12. The top surface of the outer peripheral ridge 12 defines the outer peripheral surface 3h of the rehabilitation pipe 3.

[0021] A female fitting portion 13 is provided on one edge portion 10f (left side in FIG. 2(a)) in the width direction (left or right in FIG. 2(a)) of the strip-shaped member 10. The female fitting portion 13 includes two raised portions 13c, 13d (outer peripheral ridges for fitting). The raised portions 13c, 13d protrude outward in the width direction from the flat strip portion 11 and are raised toward the outer periphery. Each raised portion 13c, 13d has a fitting groove 13a, 13b that opens to the inner periphery (lower side in FIG. 2(a)). The protruding height of the raised portions 13c, 13d is approximately equal to the protruding height of the outer peripheral ridge 12. The top surfaces of the raised portions 13c, 13d are approximately flush with the top surface of the outer peripheral ridge 12 and form part of the outer peripheral surface 3h of the rehabilitation pipe 3.

[0022] As shown in Figure 2(a), an outer circumferential groove 13f is formed between the raised portions 13c, 13d. The top of the raised portion 13d on the side connected to the flat belt portion 11 is flush with and integral with the top of the outer circumferential ridge 12 on the side closest to the edge portion 10f. Therefore, the outer circumferential ridges 13c, 12 and the outer circumferential grooves 13f, 15 are formed alternately in the belt width direction on the belt-shaped member 10.

[0023] As shown in Figure 2(a), a male fitting portion 14 is provided on the other edge portion 10e in the width direction of the belt-shaped member 10 (the right side in Figure 2(a)). The male fitting portion 14 includes two fitting ridges 14a, 14b. The fitting ridges 14a, 14b protrude from the flat belt portion 11 toward the outer periphery (upper side in Figure 2(a)) and are arranged parallel to each other in the width direction.

[0024] The belt-shaped member 10 has higher rigidity than, for example, a general belt-shaped member having a T-shaped cross-section rib and a thin flat belt portion. The cross-sectional shape of the belt-shaped member 10 can be modified as appropriate.

[0025] As shown in FIG. 2(b), in the rehabilitating pipe 3, the male and female mating portions 13, 14 of adjacent edge portions 10f, 10e that are one turn apart of the spirally wound strip-shaped member 10 are mated with each other to form a helical mating rib 16. The helical mating rib 16 includes two (multiple) mating ribs 16a, 16b, and extends helically over the entire area of ​​the rehabilitating pipe 3. The mating groove 13a and the mating rib 14a form a first mating rib 16a. The mating groove 13b and the mating rib 14b form a second mating rib 16b. Note that, as shown in FIG. 2(c), the mating rib 14b is cut off during the expansion and pipe manufacturing process of the rehabilitating pipe 3.

[0026] As shown in Figure 2(b), an outer circumferential groove 15A is formed between adjacent outer circumferential ridges 12 and raised portions 13c that are offset from each other by one circumference in the rehabilitating pipe 3. Therefore, the outer circumferential ridges 13c, 12 and the outer circumferential grooves 13f, 15, 15A are formed alternately in the pipe axial direction on the outer circumferential surface 3h of the rehabilitating pipe 3.

[0027] 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 opening 1e on the starting side (first side) of an existing pipe 1 is provided with a push-type pipe making machine 5.

[0028] <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 edge portions 10f, 10e that are one turn apart are mated with each other, and the mating grooves 13b and mating ridges 14b are mated with each other (Figure 2(b)). In this way, a rehabilitated pipe 3 is made from the strip-shaped member 10.

[0029] 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 provided on the pipe making machine 5. The time required for the water-stopping material 41 to harden is several days to several weeks or more. It should be noted that a hot melt adhesive 42 is applied to the fitting groove 13b when the belt-shaped member 10 is manufactured.

[0030] 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 10f, 10e when the recesses and protrusions are fitted together.

[0031] As shown in Figure 1(a), the rehabilitating pipe 3 produced by the pipe producing machine 5 has a smaller diameter than the inner diameter of the existing pipe 1. As shown by arrow a in the figure, the pipe producing machine 5 is driven in the forward direction, causing the rehabilitating pipe 3 to rotate while being produced and to be pushed into the existing pipe 1. In this way, the rehabilitating 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.

[0032] <Expanded pipe manufacturing process> As shown in FIG. 1(a), when the end 3f of the rehabilitating pipe 3 on the arrival side reaches the manhole 4B on the arrival side, the end 3f is prevented from rotating by a stopper 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 sequentially 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 Figure 2(c), the fitting ridge 14b is cut from its base by the restraint weakening wire 20 during the take-up.

[0033] As shown in Figure 1(b), this causes the restraining force of the helical mating groove 16 to be gradually weakened from the pipe end 3f of the rehabilitating pipe 3 toward the starting side (first side, right side in Figure 1). Furthermore, as the pipe making machine 5 drives the subsequent band portion 19 of the unmade pipe of the band-shaped member 10 to be fed to the pipe end 3e, the unweakened small-diameter pipe portion 3b of the rehabilitating pipe 3 is twisted, and the edges 10f, 10e that make up the helical mating groove 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. This causes the pipe portion 3a to be attached to the inner wall of the existing pipe 1.

[0034] 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 pipe portion 3a and the small-diameter pipe portion 3b. As the pipe portion 3a extends, the cone portion 3c moves to the starting side (first side).

[0035] As shown in Figures 1(b) and 2(d), once the cone portion 3c has been moved close to the starting pipe opening 1e, the mating ridge 14b of the trailing band portion 19 before pipe production is pre-cut by the cutting jig 8 (pre-cutting process). 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 opening 1e.

[0036] Therefore, before the end of the expansion pipe making process, of the two adjacent concave-convex fitting lines 16a, 16b of the spiral fitting line 16, the fitting convex line 14b of one of the concave-convex fitting lines 16b is cut over the entire area of ​​the rehabilitating pipe 3. This allows the rehabilitating pipe 3 to smoothly expand close to the pipe making machine 5 and come into close contact with the inner wall of the existing pipe 1, as shown in Figure 1(c). The preliminary cutting step of the fitting protrusion 14b of the trailing band portion 19 may be omitted. In this way, the expansion pipe making process is completed.

[0037] As shown in Figures 1(c) and 3, the starting-side pipe portion 3d (the first side pipe portion near the pipe making machine) of the rehabilitation pipe 3 appears in the manhole 4 between the starting-side pipe opening 1e and the pipe making machine 5. An elastic stress acts on the starting-side pipe portion 3d, causing it to expand radially outward. 3 and other figures, the helical lead angle of the rehabilitating pipe 3, including the starting-side pipe portion 3d, is exaggerated for convenience of illustration. In an actual rehabilitating pipe 3, the winding direction of the strip-shaped member 10 is oriented substantially in the pipe circumferential direction, and the strip width direction is oriented substantially in the pipe axial direction.

[0038] <Predetermined winding part> As shown by the hatched pattern in Figure 3, a predetermined winding portion 17 of the belt-shaped member 10 is virtually set within the starting-side pipe portion 3d. The predetermined winding portion 17 is set between two thread portions 16c, 16d spaced apart by one turn (one pitch) of the helical engagement thread 16, preferably on the upper circumferential side portion 3da of the starting-side pipe portion 3d. The length of the predetermined winding portion 17 along the winding direction of the belt-shaped member 10 in the starting-side pipe portion 3d is preferably at least a quarter of a circumference but not more than half a circumference.

[0039] As shown in Figure 3, the predetermined winding portion 17 has, for example, a roughly triangular shape in a plan view. In the starting-side pipe portion 3d, the subsequent winding portion 18 continues on the subsequent side of the predetermined winding portion 17 in the winding direction, i.e., on the side that connects to the subsequent band portion 19 (Figure 1(a)) (lower side in Figure 3). The imaginary boundary 17e between the predetermined winding portion 17 and the subsequent winding portion 18 in the starting-side pipe portion 3d transitions, for example, in a stepped manner, from the strip portion 16c on the starting-side pipe opening 1e side (second side) to the strip portion 16d on the pipe making machine 5 side (first side) toward the opposite side from the subsequent side in the winding direction, i.e., the winding advance side (upper side in Figure 3).

[0040] <Post-process> After the expansion pipe making process is completed, the starting pipe portion 3d is cut along the boundary 17e, and the pipe making machine 5 is separated from the rehabilitating pipe 3.

[0041] <Incision process> More specifically, after the expansion pipe making process and prior to the cutting process, a row of cuts 30 is formed on the outer circumferential surface of the predetermined winding portion 17 of the starting-side pipe portion 3d, as shown in Fig. 4. As shown by the two-dot chain line in Fig. 5(a), the cutting work is performed using a cutting tool 61 such as a grinder or a cutter.

[0042] 4, the incision row 30 includes a plurality of incisions 31, 32. These incisions 31, 32 each extend in a direction intersecting the winding direction of the belt-shaped member 10 in the predetermined winding portion 17 (substantially the same direction as the axial direction of the rehabilitating pipe 3), and are spaced apart from one another in the winding direction of the belt-shaped member 10. The order in which the incisions 31 and 32 are formed can be selected arbitrarily.

[0043] The predetermined winding portion 17, which is the area where the cut is made, is set on the upper circumferential side portion 3da of the starting-side pipe portion 3d, so the cutting work can be carried out easily. Even if the lower circumferential side portion of the starting-side pipe portion 3d is fitted into the bottom invert 9 of the starting-side manhole 4 (see Figure 1(a)), the cutting work is not hindered.

[0044] As shown in FIG. 4, it is preferable that the interval P of the notches 31 on the trailing side (lower side in FIG. 4) of the predetermined winding portion 17 in the winding direction is 31 The distance P between the notches 32 on the side opposite to the subsequent side in the winding direction from the notch 31, i.e., on the winding advance side (upper side in FIG. 4), is 32 The spacing P of the notches 31 is made smaller. 31 is the spacing P of the cut 32 32 Preferably, it is about 0.4 to 0.6 times (0.4 × P 32 ≦P 31 ≦0.6×P 32 ), and more preferably, the interval P 32 About half of (P 31 ≒0.5 × P 32 ) For example, P 31 =about 25mm, P 32 = about 50mm.

[0045] The notches 31 at the small interval P31 are formed in the portion (hereinafter referred to as the "cut-out strip portion 16e") on the subsequent side in the winding direction (the lower side in FIG. 4) of the second side strip portion 16c of the helical interlocking strip 16. The length of the notch 31 may be approximately the length that crosses the cut-out strip portion 16e. The notch 31 may extend further toward the first side strip portion 16d than the cut-out strip portion 16e.

[0046] The notches 32 at the large interval P32 are formed longer than the notches 31 from the second side strip portion 16c toward the first side strip portion 16d. The slits 32 may be lengthened toward the first side strip portion 16d in the winding direction (upper side in FIG. 4). The slits 32 may be lengthened in stages every several slits (three slits in FIG. 4) toward the winding direction.

[0047] The incision row 30 may extend beyond the predetermined winding portion 17. Each incision 31, 32 may extend from the predetermined winding portion 17 across the boundary 17e to the subsequent winding portion 18. Each incision 31, 32 may be long enough to reach from the second side strip portion 16c to the first side strip portion 16d. Alternatively, the row of incisions 30 do not necessarily have to be formed over the entire area of ​​the predetermined winding portion 17. The end of each incision 32 on the pipe making machine 5 side (the right side in Figure 4) does not have to reach the boundary 17e. In the winding advance side portion of the predetermined winding portion 17 (the upper portion in Figure 4), the incisions 32 may be omitted.

[0048] As shown in Figures 5(a) to 5(c), each of the notches 31, 32 opens into the outer peripheral surface 3h of the starting-side pipe portion 3d. The depth of each of the notches 31, 32 is less than the pipe thickness of the rehabilitating pipe 3 (less than the thickness of the band-shaped member 10). Therefore, the notches 31, 32 do not reach the inner peripheral surface 3g of the starting-side pipe portion 3d. Preferably, the depth of the notches 31, 32 is less than the protruding height of the outer peripheral ridge 12, and the notches 31, 32 do not reach the flat band portion 11. More preferably, the depth of the notches 31, 32 is between one-half and two-quarters of the pipe thickness of the rehabilitating pipe 3 (the thickness of the band-shaped member 10), and even more preferably about two-thirds.

[0049] The elastic stress acting radially outward in the predetermined turn portion 17 of the start-side pipe portion 3d is weakened by the formation of the cuts 31 and 32. In particular, the cuts 31 at the small intervals P31 sufficiently weaken the elastic stress in the cut-out strip portion 16e.

[0050] <Cutting process> Next, as shown in Fig. 6, the upper peripheral portion 3da of the starting-side pipe portion 3d is cut along the boundary 17e from the outer peripheral surface 3h to the inner peripheral surface 3g across the entire width of the strip-shaped member 10 of the starting-side pipe portion 3d. This forms a strip division line 50 that separates the predetermined winding portion 17 from the subsequent winding portion 18. As shown by the two-dot chain line in Fig. 5(b), the cutting operation is performed using a cutting tool 62 such as a saber saw or a cutter. The cutting tool 62 may be the same as the incising tool 61.

[0051] More specifically, as shown in Fig. 6, first, the end of the cut-out strip portion 16e on the trailing side in the winding direction (the lower side in Fig. 6) is cut across to form the convex transverse strip line 51. The cut-out strip portion 16e may be cut along the trailing-most (the lowermost in Fig. 6) notch 31A. By doing so, the pipe thickness to be cut is reduced by the depth of the notch 31A, making cutting easier.

[0052] By cutting the end of the cut-out strip portion 16e at the beginning of the cutting process, the male and female mating portions 13, 14 of the spiral mating strip 16 slide off each other in the winding direction when the tube is subsequently cut in the circumferential direction or the winding direction, making it less likely that the mating will come loose.

[0053] Additionally, the lateral portion of the cut strip portion 16e on the pipe making machine 5 side (first side, right side in FIG. 6) is cut along the winding direction. Preferably, the cut is made vertically across the outer circumferential groove 13f to form a groove vertical cutting line 52. This reduces the pipe thickness to be cut and allows the cutting tool 62 to be guided along the outer circumferential groove 13f, making cutting easier.

[0054] As a result, the cut-out strip portion 16e is cut out. The elastic stress of the cut-out strip portions 16e is weakened by the cutting process, so that they can be prevented from warping outward in the pipe radial direction during cutting. In particular, the elastic stress of the cut-out strip portions 16e is sufficiently weakened by the cut-out strip portions 31 at the small intervals P31, so that they can be reliably prevented from being deformed outward in the pipe radial direction. Even if the strip-shaped member 10 has high rigidity, the cut-out strip portions 16e can be reliably prevented from being deformed in such a way that they jump outward in the pipe radial direction.

[0055] Furthermore, the starting-side pipe portion 3d is cut from the cutout strip portion 16e toward the first side strip portion 16d. At this time, the cutting is performed toward the winding-advance side (upward in FIG. 6) as the cutting approaches the first side strip portion 16d. Specifically, the cutting is performed so that the strip division line 50 has a stepped shape including a convex strip cross line 53 that crosses the outer peripheral convex strips 13d, 12, and 13c and a groove vertical cut line 54 that vertically crosses the outer peripheral groove 15.

[0056] Preferably, the transverse ridge line 53 is formed along the incision 32. By doing so, the thickness of the pipe to be cut is reduced by the depth of the incision 32, making it easier to form the transverse ridge line 53. Furthermore, by cutting the outer peripheral groove 15 vertically, the pipe thickness to be cut can be reduced and the cutting tool 62 can be guided along the outer peripheral groove 15, facilitating the formation of the groove vertical cutting lines 33. The length of each groove vertical cutting line 33 is preferably several times (e.g., three times) the spacing P32 between the incisions 32. This allows the band-dividing cutting line 50 to bend in a stepped shape every time it crosses several (three in FIG. 5 ) incisions 32.

[0057] As shown in Figures 5(c) and 6, the band dividing line 50 is formed until it crosses the first side strip portion 16d, thereby cutting the entire width of the band-shaped member 10 of the starting-side pipe portion 3d. As a result, as shown in Figure 6, the predetermined winding portion 17 and the subsequent winding portion 18 are separated on either side of the band dividing line 50. The predetermined winding portion 17 is connected to the rehabilitating pipe 3 in the existing pipe 1. The subsequent winding portion 18 is connected to the starting-side pipe end portion 3e in the pipe making machine 5 and further to the subsequent band portion 19 (Figure 1).

[0058] The elastic stress acting radially outward in the predetermined winding portion 17 is weakened by the cut row 30. Therefore, the predetermined winding portion 17 can be prevented from deforming and curling outward in the radial direction of the pipe when the belt-shaped member 10 is severed. Even if the belt-shaped member 10 has high rigidity, deformation of the predetermined winding portion 17 can be reliably prevented. This makes it possible to prevent disengagement of the helical engaging rib 16 from occurring, starting from the cut portion of the helical engaging rib 16 in the predetermined winding portion 17.

[0059] The band dividing line 50 only needs to be formed on the upper peripheral side portion 3da of the starting-side pipe portion 3d, making the cutting work easy. Even if the lower peripheral side portion of the starting-side pipe portion 3d is fitted into the bottom invert 9 of the starting-side manhole 4, the cutting work is not hindered.

[0060] <Reverse drive process> Next, as shown in Figure 7, the pipe making machine 5 is driven in reverse. That is, the pipe making machine 5 is driven to rotate in the opposite direction to the rotation direction in the original push pipe making process and the expansion pipe making process (when the strip-shaped member 10 is supplied). As a result, as shown by arrow b in Figure 7, the subsequent wound portion 18 is wound toward the subsequent side, i.e., the starting side pipe end portion 3e side, and further toward the subsequent strip portion 19 side.

[0061] On the other hand, as shown in FIG. 8, the predetermined winding portion 17 is cut off from the pipe making machine 5 by the strip breaking wire 50, and therefore is not wound up and remains as the leading end of the rehabilitating pipe 3 in the winding direction. During the reversal step, the water-stopping material 41 made of a slow-hardening adhesive is not yet hardened.

[0062] This separates the pipe making machine 5 from the rehabilitation pipe 3 inside the existing pipe 1. After separation, the pipe making machine 5 is removed from the starting manhole 4. The pipe making machine 5 may be disassembled into a size that can be carried out from the ground entrance of the starting manhole 4 before being carried out.

[0063] Next, another embodiment of the present invention will be described. In the following embodiment, the same components as those already described will be denoted by the same reference numerals in the drawings, and the description thereof will be omitted. <Second embodiment (FIG. 9)> The band dividing line 50 does not necessarily have to be stepped. For example, in the second embodiment shown in Fig. 9, the starting-side tube portion 3d is cut obliquely and almost straight from the trailing end of the cut-out strip portion 16e in the winding direction to the leading end of the first side strip portion 16d in the winding direction, forming a diagonal strip cutting line 50 that is almost straight. The incisions 31 and 32 extend in a direction intersecting the winding direction from the cut-out strip portion 16e to a position where they intersect with the band dividing line 50. Note that the incisions 31 and 32 may also extend further toward the pipe making machine 5 (first side, right side in FIG. 9) than the band dividing line 50.

[0064] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the entire area between two adjacent thread portions 16c, 16d of the helical interlocking thread 16 in the starting-side pipe portion 3d may be defined as the predetermined winding portion 17, and the cut lines 31, 32 may be formed in the entire area. In the cutting step, the starting-side pipe portion 3d may be cut substantially along the pipe axis direction. The band division line 50 may be substantially along the pipe axis direction. The cuts 31, 32 and the band dividing line 50 may extend to the lower peripheral side of the departure-side pipe portion 3d. [Industrial Applicability]

[0065] The present invention is applicable to, for example, rehabilitation work of deteriorated sewer pipes. [Explanation of symbols]

[0066] 1. Existing pipes (pipes to be rehabilitated) 1e Starting pipe opening (first pipe opening) 3 Rehabilitation pipe (spiral pipe) 3e Starting side (first side) pipe end 3g Inner surface 3h Outer surface 5 Pipe making machine 6 Drums 10. Belt-shaped member 10f One edge 10e Other edge 11 Flat belt 12 Reinforcing outer circumferential ridges 13 Female mating part 13c, 13d Protrusions (outer peripheral protrusions for fitting) 13f outer groove 14 Male mating part 14a,14b Fitting protrusion 15 Peripheral groove 16 Spiral mating groove 16a,16b Uneven mating strip 16c 2nd side strip part 16d 1st side strip part 16e Cutout section 17 Predetermined winding part 18 Subsequent winding section 19 Trailing belt 30 cut rows 31 Cutting 32 Cutting 50 Band split line 51 Convex transverse line 52 Groove longitudinal section 53 Convex transverse line 54 Groove longitudinal section 61 Cutting tools 62 Cutting tools

Claims

1. a pipe rehabilitation method comprising: placing a helical rehabilitating pipe, which is formed by helically winding a long strip-shaped member, in a pipe to be rehabilitated; gradually weakening the binding force of a helical fitting rib, which is formed by adjacent edges of the strip-shaped member that are offset by one turn, in the axial direction of the rehabilitating pipe from a second side to a first side of the rehabilitating pipe; supplying a subsequent strip of unmanufactured pipe of the strip-shaped member to the first side end of the rehabilitating pipe using a pipe manufacturing machine engaged with the first side end of the rehabilitating pipe, thereby expanding the circumferential length of the weakened pipe portion of the rehabilitating pipe; and then cutting a first side pipe portion of the rehabilitating pipe near the pipe manufacturing machine to separate the pipe manufacturing machine from the rehabilitating pipe; Prior to the cutting step, a plurality of notches are formed in the outer peripheral surface of a predetermined wound portion of the belt-shaped member in the first side tube portion, the notches extending in a direction intersecting the winding direction of the belt-shaped member and spaced apart from one another in the winding direction, Next, in the cutting step, the belt-shaped member in the first side tube portion is cut between the predetermined winding portion and a subsequent winding portion on the subsequent belt portion side, i.e., the subsequent side, in the winding direction relative to the predetermined winding portion to form a band dividing line that divides the predetermined winding portion and the subsequent winding portion, Next, in the separation process, the pipe making machine is driven in the reverse direction from the supplying direction to wind the subsequent wound portion onto the subsequent side, which is a pipe rehabilitation method characterized by the above.

2. 2. The pipe rehabilitation method according to claim 1, wherein the spacing of the notches in the cut-out portion of the spiral fitting strip along the edge of the second side and the trailing side of the specified winding portion is made smaller than the spacing of the notches on the side opposite the trailing side in the winding direction from the cut-out portion.

3. A pipe rehabilitation method as described in claim 2, wherein in the cutting process, the trailing end of the cut-out strip portion is cut transversely, and the first side portion of the cut-out strip portion is cut longitudinally along the winding direction.

4. 3. The pipe rehabilitation method according to claim 2, wherein in the cutting step, the first side pipe portion is cut so as to move toward the opposite side of the winding direction as it approaches a first side stripe portion that is shifted one turn toward the first side from the cut-out stripe portion of the spiral fitting strip.

5. The belt-shaped member has a plurality of outer peripheral protrusions and outer peripheral grooves extending in the belt length direction and alternately formed in the belt width direction, 5. The pipe rehabilitation method according to claim 4, wherein the first side pipe portion is cut so that the band division line forms a stepped shape including a groove longitudinal line that extends longitudinally through the outer peripheral groove and a convex strip cross line that crosses the outer peripheral convex strip.

6. The pipe rehabilitation method according to any one of claims 1 to 5, wherein the depth of the cut is such that it does not reach the inner peripheral surface of the first side pipe portion.

7. the belt-shaped member has a flat belt portion that defines the inner peripheral surface, and a reinforcing outer peripheral ridge that protrudes from the flat belt portion toward the outer peripheral side and extends in the belt length direction, A pipe rehabilitation method according to any one of claims 1 to 5, wherein the depth of the cut is equal to or less than the protruding height of the reinforcing outer peripheral ridge.

8. A pipe rehabilitation method according to any one of claims 1 to 5, wherein the depth of the cut is between one-half and three-quarters of the pipe thickness of the rehabilitated pipe.

9. The pipe rehabilitation method according to any one of claims 1 to 5, wherein the predetermined winding portion is set on an upper peripheral side portion of the first side pipe portion.

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