Method for rehabilitating existing pipes and a pipe-forming machine used in the said method

Abstract

To provide a finishing method which is capable of smoothly expanding a pipe end part of a regeneration pipe and can reduce workload of an operator after cutting and releasing in an expander pipe making method.SOLUTION: A belt-like member 10 is wound spirally along an inner periphery of a circumference regulation body 21 of a former push pipe making machine 20 for pipe forming of a spiral tubular regeneration pipe 3 to be smaller diameter than an existing pipe 1. Then, a restraint force of a spiral junction 12 is sequentially weakened from a tip side in an indentation direction of the regeneration pipe 3 to a former push side, and a trailing belt part 19 of the belt-like member 10 is sent to the regeneration pipe 3 by using the former push pipe making machine 20 to expand a peripheral length of a part where the restraining force of the regeneration pipe 3 has been weakened and is bonded to an inner periphery face of the existing pipe 1. When a distance from an end part 32f on a large-diameter tube part 33 side of a cone part 32 between the large-diameter tube part 33 having been bonded in the regeneration pipe 3 and a small diameter pipe part 30 to the former push pipe making machine 20 becomes a prescribed length L or under, a diameter of a circumference regulation body 21 is desirably gradually expanded.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a method for rehabilitating existing pipes by constructing a spiral-shaped rehabilitation pipe along the inner circumference of an aging existing pipe by means of a so-called expander (expansion) method, and a pipe-making machine used for this method. In particular, it relates to a finishing method after the expansion of the rehabilitation pipe reaches near the pipe-making machine.

Background Art

[0002] There is known a method for rehabilitating existing pipes by constructing a spiral-shaped rehabilitation pipe made of a strip member (profile) along the inner circumference of an existing pipe such as an aging sewer pipe (see Patent Documents 1 to 3, etc.). Patent Document 1 discloses a pipe-making machine for manufacturing a rehabilitation pipe. The pipe-making machine has an annular outer peripheral regulating body and is installed in a starting manhole connected to an existing pipe. By winding a strip member spirally along the inner circumference of the outer peripheral regulating body and joining adjacent edges thereof by means of concave-convex fitting, a spiral-shaped rehabilitation pipe is manufactured to have a smaller diameter than the inner diameter of the existing pipe, while sequentially pushing the rehabilitation pipe into the existing pipe.

[0003] Patent Documents 2 and 3 disclose a method for rehabilitating existing pipes by means of a so-called expander method. Specifically, when manufacturing a rehabilitation pipe from a strip member by a pipe-making machine at a starting manhole, a restraint weakening wire is interposed between adjacent edges of the strip member. When the tip portion in the pushing direction of the rehabilitation pipe reaches the pipe mouth on the reaching side, after fixing the tip portion (reaching side end portion) in the pushing direction, the restraint weakening wire is pulled out, and ridges constituting a part of the joint portion of the adjacent edges are sequentially cut along the winding direction to weaken the joining force. In parallel, by further supplying the strip member to the rehabilitation pipe by the pipe-making machine, the starting side end portion of the rehabilitation pipe is twisted and rotated. As a result, the adjacent edges of the joint portion with the weakened joining force slide, and the circumference of the rehabilitation pipe is sequentially expanded (increased in diameter) from the reaching side to the starting side and is attached to the inner peripheral surface of the existing pipe.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2011-106561 [Patent Document 2] Japanese Patent Publication No. 2021-115749 [Patent Document 3] Japanese Patent Publication No. 2021-115750 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The expander method eliminates the need for backfill injection, and compared to other methods, it is expected to shorten construction time and reduce construction costs. 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 to the expanded large-diameter pipe section in the rehabilitation pipe. If the cone length is too long, poor adhesion to the inner surface of the existing pipe will occur. If the cone length is too short, the angle of the cone becomes too steep, causing buckling (breakage of the interlocking grooves between adjacent edges) between the unexpanded small-diameter pipe section and the cone section. In particular, during the finishing stage after the rehabilitation pipe has been expanded to near the pipe end on the launching manhole side, it is difficult to ensure a sufficient cone length, and buckling is likely to occur. Generally, in existing pipes such as sewers, the launching manhole is narrow, and the main pipe-making machine can only be placed about 200 mm away from the pipe opening of the existing pipe.

[0006] In the finishing methods described in Patent Documents 2 and 3, when the expansion of the rehabilitated pipe reaches near the pipe end on the launching manhole side, the main pipe-making machine is stopped, the restraining weakening wire is pulled back to the position closest to the main pipe-making machine, the rehabilitated pipe is cut at that position and released from the main pipe-making machine, and the cone-shaped pipe end portion of the released rehabilitated pipe is manually twisted to expand the diameter or allowed to expand naturally. However, with this method, the pipe end portion that needs to be manually expanded is long, which places a heavy burden on the worker. The time required for both manual and natural expansion is also long. In view of these circumstances, the present invention aims to provide a finishing method for pipe construction using an expander that allows for smooth expansion of the pipe end portion of the rehabilitated pipe, reduces the workload of the worker in manually expanding the diameter after cutting and releasing, and shortens the time required for manual or natural expansion. [Means for solving the problem]

[0007] To solve the aforementioned problems, the present invention provides a method for rehabilitating an existing pipe, in which a strip-shaped member is wound spirally along the inner circumference of an annular outer peripheral restrictor of the main-push pipe-forming machine installed in a launching manhole connected to the existing pipe, and adjacent edges of the strip-shaped member that are one rotation apart are fitted together to form a spiral-shaped rehabilitation pipe with a diameter smaller than the inner diameter of the existing pipe, and the rehabilitation pipe is pushed into the existing pipe to install the rehabilitation pipe inside the existing pipe, and then, while sequentially weakening the restraining force between adjacent edges of the rehabilitation pipe from the tip side in the pushing direction toward the main-push side along the winding direction, the subsequent strip portion of the strip-shaped member that follows the pipe end of the rehabilitation pipe on the main-push side is sequentially fed into the rehabilitation pipe by the main-push pipe-forming machine, thereby expanding the circumference of the portion of the rehabilitation pipe where the restraining force has been weakened and attaching it to the inner surface of the existing pipe, The present invention is characterized in that when the distance from the end of the cone portion on the large-diameter pipe portion side to the main pipe-making machine, which is formed between the attached large-diameter pipe portion and the small-diameter pipe portion in the rehabilitated pipe whose restraining force has not been weakened, falls within a predetermined length, an enlargement step is performed to enlarge the outer peripheral regulating body.

[0008] When the outer diameter regulating body is expanded, the subsequent band portion newly fed to the main pipe-making machine in the subsequent expansion process is formed while being wound spirally along the inner circumference of the expanded outer diameter regulating body. Therefore, the new diameter of the rehabilitated pipe is expanded. When the cone section joins this, the smaller diameter end of the cone section is expanded and the cone length is shortened. Since the cone angle can be kept constant, buckling at the smaller diameter end of the cone section can be prevented even if the cone length is shortened. The larger diameter end of the cone section can be made to adhere firmly to the inner surface of the existing pipe. This allows for smooth and efficient expansion of the main pipe end portion of the rehabilitated pipe. Subsequently, the pipe end portion of the rehabilitated pipe is cut between the pipe opening to the launch manhole of the existing pipe and the main pipe-making machine, thereby freeing it from the main pipe-making machine. The freed pipe end portion of the rehabilitated pipe includes a cone section with a short cone length. The pipe end is manually expanded by twisting it by the worker, or it expands naturally. Because the cone length of the cone section at the pipe end is short, the burden on the worker during manual expansion is reduced, and the time required for manual or natural expansion is shortened.

[0009] The outer diameter expansion process of the outer diameter restrictor is carried out in stages in multiple steps. Preferably, a restraint weakening and expansion process is interposed between adjacent diameter expansion processes. This prevents the outer diameter restrictor from being greatly expanded at once, thus preventing the pipe end portion on the main pushing side of the rehabilitation pipe from coming off the outer diameter restrictor.

[0010] The main pipe forming machine used in the aforementioned existing pipe rehabilitation method has an outer circumference restricting body, A ring frame and A plurality of guide rollers are arranged in the circumferential direction of the annular frame and engage with the outer groove of the strip-shaped member to guide the strip-shaped member, A diameter adjustment portion is provided at one location in the circumferential direction of the annular frame and expands and contracts along the circumferential direction. It is preferable that it is equipped with [a specific feature]. The annular frame and, consequently, the outer peripheral regulating body are expanded or contracted by the expansion or contraction of the diameter adjustment section. Preferably, by performing the expansion operation of the diameter adjustment section and the expansion process of the outer peripheral regulating body in multiple steps, it is possible to avoid disengaging the outer peripheral groove from the guide roller and maintain the guiding function of the guide roller for the strip-shaped member. [Effects of the Invention]

[0011] According to the present invention, in the pipe expansion method using an expander, the pipe end portion of the rehabilitated pipe can be smoothly and effectively expanded so as not to cause buckling and so as to firmly adhere 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. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is an explanatory side view showing the pipe manufacturing process of the rehabilitated pipe in the existing pipe rehabilitation method according to one embodiment of the present invention. [Figure 2(a)] Figure 2(a) is a front view along line IIa-IIa in Figure 1, showing the main pipe press machine used for the main pipe press method with the outer circumference restricting body in a reduced diameter state. [Figure 2(b)] Figure 2(b) is a front view of the main pipe-making machine along line IIb-IIb in Figure 10, showing the outer diameter regulating body in an expanded state. [Figure 3] Figure 3(a) is a cross-sectional view of the outer perimeter regulating body along the line IIIa-IIIa in Figure 2(a). Figure 3(b) is a cross-sectional view of the outer perimeter regulating body along the line IIIb-IIIb in Figure 2(a). [Figure 4] Figure 4(a) is a perspective cross-sectional view of circular section IVa in Figure 1, showing the helical joint of the rehabilitated pipe in the initial pipe-forming process. Figure 4(b) is a perspective cross-sectional view of circular section IVb in Figure 5, showing the helical joint of the rehabilitated pipe in the restraint weakening process. Figure 4(c) is a perspective cross-sectional view of circular section IVc in Figure 5, showing the helical joint of the rehabilitated pipe in the expansion process. [Figure 5] Figure 5 is an explanatory side view showing the existing pipe rehabilitation method in the restraint weakening and expansion steps before the finishing process. [Figure 6] Figure 6 is an explanatory side view showing the existing pipe rehabilitation method in the first diameter expansion step of the finishing process. [Figure 7] Figure 7 is an explanatory side view showing the existing pipe rehabilitation method in the restraint weakening step and the expansion step after the first diameter expansion step. [Figure 8] Figure 8 is an explanatory side view showing the existing pipe rehabilitation method in the second diameter expansion step. [Figure 9] Figure 9 is an explanatory side view showing the existing pipe rehabilitation method in the restraint weakening step and the expansion step after the second (final) diameter expansion step. [Figure 10] Figure 10 is an explanatory side view showing the existing pipe rehabilitation method at the stage where the restraint weakening step and the expansion step after the final diameter expansion step have progressed. [Figure 11] Figure 11 is an explanatory side view showing the existing pipe rehabilitation method at the stage where the restraint weakening step and the expansion step after the final diameter expansion step have further progressed. [Figure 12] Figure 12 is an explanatory side view showing the existing pipe rehabilitation method at the end of the restraint weakening step and the expansion step. [Figure 13] Figure 13 is an explanatory side view showing the existing pipe rehabilitation method in the cutting release step. [Figure 14] Figure 14 is an explanatory side view showing the existing pipe rehabilitation method at the completion stage of the rehabilitation construction.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows the state of rehabilitating the deteriorated existing pipe 1. The existing pipe 1 to be rehabilitated is, for example, a sewer pipe buried underground. Note that the object to be rehabilitated in the present invention is not limited to sewer pipes, and may also be water supply pipes, agricultural water pipes, gas pipes, water conduits for hydroelectric power generation, tunnels, etc. The existing pipe 1 is rehabilitated by lining the rehabilitation pipe 3 on the inner circumference of the deteriorated existing pipe 1.

[0014] As shown in Figure 1, the rehabilitation pipe 3 is a spiral pipe made of a strip-shaped member 10. The material of the strip-shaped member 10 is a synthetic resin such as polyvinyl chloride (PVC). As shown in Figures 3 and 4, the strip-shaped member 10 is a long strip with a certain cross-sectional shape. Fitting portions with an uneven cross-section are formed on both edge portions 13 and 14 in the width direction of the strip-shaped member 10. Specifically, on one edge portion 13, two (or more) first grooves 13a and second grooves 13b are formed side by side, opening toward the inner circumference (upper side in Figure 3). On the other edge portion 14, two (or more) first protrusions 14a and second protrusions 14b are formed side by side, projecting toward the outer circumference (downward side in Figure 3). In the middle of the strip-shaped member 10 in the width direction, multiple ribs 15 with a T-shaped cross-section are formed, projecting toward the outer circumference (downward side in Figure 3). Outer circumferential grooves 16 are formed between the ribs 15, or between the raised portion 13d on the outer circumference side of the edge portion 13 and the ribs 15. The cross-sectional shape of the strip-shaped member 10 is not limited to those shown in Figures 3 and 4, and can be modified as appropriate.

[0015] As shown in Figure 4, the strip-shaped member 10 in the rehabilitation pipe 3 is wound in a spiral shape, and adjacent edge portions 13 and 14 that are one turn apart are interlocked with each other. Specifically, the first protrusion 14a is fitted into the first recess 13a, and the second protrusion 14b is fitted into the second recess 13b. As shown in Figure 1, a spiral joint portion 12 consisting of edge portions 13 and 14 is formed in the rehabilitation pipe 3.

[0016] As shown in Figure 1, the rehabilitated pipe 3 is manufactured by a pipe press machine 20. As shown in Figure 2(a), the pipe press machine 20 includes an annular outer peripheral regulating body 21, a strip member introduction section 22, and a pinch section 23. The outer peripheral 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 a spirally twisted annular shape. The circumferential ends of the lower semicircular frame section 27 are connected to the upper quartercircular frame sections 28 via side boxes 29. The lower end of each upper quartercircular frame section 28 is rotatably connected to the upper end of the side box 29.

[0017] As shown in Figure 2(a), a diameter adjustment section 26 is provided at the upper end (one location in the circumferential direction) of the annular frame 24. The diameter adjustment section 26 is interposed between the upper ends of a pair of upper quarter-circular frame sections 28. The diameter adjustment section 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 section 28. The adjustment bolt 26b is stretched across the middle of the pair of arms 26a. The threaded portion of the adjustment bolt 26b is screwed into a nut 26d provided on one of the arms 26a (the left arm in Figure 2(a)). The tip of the adjustment bolt 26b is rotatably and non-slidably locked to the other arm 26a (the right arm in Figure 2(a)). Alternatively, the adjustment bolt 26b may be slidably supported on one arm 26a (the left arm in Figure 2(a)) and screwed into a nut on the other arm 26a (the right arm in Figure 2(a)).

[0018] As shown in Figures 2(a) and 2(b), by adjusting the amount the adjustment bolt 26b is screwed in, the angle between the pair of arms 26a is increased or decreased, and the diameter adjustment section 26 expands or contracts along the circumferential direction of the annular frame 24. As a result, the upper ends of the pair of upper quarter-circular frame sections 28 move closer together and further apart, allowing the annular frame 24 to expand or contract in diameter.

[0019] As shown in Figure 2(a), a plurality of guide rollers 25 are rotatably mounted in a line along the circumferential direction of the annular frame 24. The axis of rotation of each guide roller 25 is oriented parallel to the axis of the annular frame 24. As shown in Figure 3, one or more annular guides 25a are provided on the guide rollers 25. As shown in Figures 3(a) and 3(b), the mounting positions of the annular guides 25a on adjacent guide rollers 25 in the circumferential direction of the annular frame 24 are shifted by the helical pitch of the strip-shaped member 10 in the direction along the axis of rotation of the guide roller 25. Guide rollers 25 with the annular guide 25a positioned on one end of the axis of rotation (right side in Figure 3(a)) and guide rollers 25 with the annular guide 25a positioned on the other end of the axis of rotation (left side in Figure 3(b)) are alternately arranged in the circumferential direction of the annular frame 24.

[0020] Each annular guide 25a is fitted into and engaged with the outer circumferential groove 16 of the strip-shaped member 10 at the starting end of the rehabilitation pipe 3. The guide roller 25 guides the strip-shaped member 10 in a spiral manner.

[0021] As shown in Figure 2(a), a pinch section 23 is provided in one of the side boxes 29 of the annular frame 24 (the left side in Figure 2(a)). The pinch section 23 includes a pair of pinch rollers 23a and 23b. The inner pinch roller 23a is positioned radially inward from the annular frame 24. A strip member introduction section 22 rises upward from the side box 29 containing the pinch section 23. The other side box 29 (the right side in Figure 2(a)) supports an inner roller 29a that presses the strip member 10 from the inner circumference.

[0022] Rehabilitated pipe 3 is manufactured using the following expander pipe construction method. <Pipe manufacturing process> As shown in Figure 1, the main pipe-forming machine 20 is installed at the bottom of the launching hole 4 connected to the pipe opening 1e on the launching side (left side in Figure 1) of the existing pipe 1. Note that because the launching hole 4 is narrow, the distance from the main pipe-forming machine 20 to the pipe opening 1e is at most about 200 mm. The strip-shaped members 10 are sequentially fed out from the ground-level dispensing drum 5, inserted into the launching manhole 4, and supplied to the main pipe-forming machine 20, which then forms the strip-shaped members 10 into spiral-shaped rehabilitated pipes 3.

[0023] More specifically, as shown in Figure 2(a), the strip-shaped member 10 is introduced into the strip-shaped member introduction section 22. From there, it is wound spirally along the inner circumference of the outer peripheral regulating body 21 via the pinch section 23, and is passed between the pinch rollers 23a and 23b in the pinch section 23 and tightly clamped. As a result, as shown in Figure 4(a), the adjacent edge portions 13 and 14 of the spirally wound strip-shaped member 10, offset by one full turn, are joined together by a concave-concave fitting. The first convex ridge 14a is fitted into the first concave groove 13a, and the second convex ridge 14b is fitted into the second concave groove 13b. Preferably, the first concave groove 13a is filled with a slow-curing adhesive 17 before fitting with the first convex ridge 14a. Preferably, the second concave groove 13b is filled with a hot-melt adhesive 18 during the manufacture of the strip-shaped member 10.

[0024] As shown in Figure 1, the rehabilitated pipes 3 produced in this manner are sequentially pushed out from the main pipe-making machine 20 and pushed into the existing pipes 1. The leading end 3f (right end in Figure 1) of the rehabilitated pipe 3 in the pushing direction may be pulled by a winch or the like.

[0025] The circumference or diameter of the rehabilitated pipe 3 can be adjusted by restricting the rehabilitated pipe 3 from the outer circumference using the outer circumference restrictor 21. During the initial press-formation of the pipe, the diameter adjustment section 26 of the outer circumference restrictor 21 is shortened, and the annular frame 24 is made relatively small in diameter (Figure 2(a)), thereby making the outer diameter (formed diameter) of the rehabilitated pipe 3 smaller than the inner diameter of the existing pipe 1. This ensures that the rehabilitated pipe 3 can be reliably pushed into the existing pipe 1 even if there are obstacles inside the existing pipe 1 or if the existing pipe 1 is slightly bent. Preferably, the outer diameter of the rehabilitated pipe 3 during the initial press-formation of the pipe is about 50 mm to 200 mm smaller than the inner diameter of the existing pipe 1.

[0026] <Wire embedding process> As shown in Figure 1, the restraint weakening wire 41 is unfurled from the feed reel 42 in parallel with the initial pipe-making process. The restraint weakening wire 41 is inserted between the first protrusion 14a and the second protrusion 14b of the unmade pipe strip member 10 (Figure 3(a)). The restraint weakening wire 41 is then sandwiched between the edge portions 13 and 14 by the subsequent interlocking of the protrusions and recesses and embedded inside the helical joint 12 (Figure 4(a)).

[0027] As shown in Figure 1, the tip portion (pull-in portion) 41b of the restraint weakening wire 41 is pulled out from the tip 3f of the rehabilitation pipe 3, folded back, and wound around the ground-based winding winch 43 via the internal space of the rehabilitation pipe 3 and the launching manhole 4. The pull-out and folded portion 41c of the wire 41 is located at the tip 3f. The winding winch 43 is in a free-rotating state during the initial pipe-making process.

[0028] As shown by the dashed line in Figure 1, the pipe manufacturing process is carried out until the rehabilitated pipe 3 reaches the pipe opening 1f on the receiving manhole 4B side of the existing pipe 1. This ensures that the rehabilitated pipe 3 is installed throughout the entire length 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 a small-diameter pipe section 30 that is smaller in diameter than the existing pipe 1 and is not expanded throughout its entire length.

[0029] <Restraint weakening process> After pipe formation, as shown in Figure 5, the winding winch 43 pulls the take-up portion 41b of the restraint weakening wire 41, thereby pulling the restraint weakening wire 41 toward the push side, i.e., the starting side (left side in Figure 5). As a result, the portion 41a of the restraint weakening wire 41 that was embedded in the helical joint 12 is sequentially pulled out from the tip side of the rehabilitation pipe 3 (right side in Figure 5), and the pull-out folded portion 41c is moved toward the push side (left side in Figure 5) along the winding direction of the spiral. At this time, as shown in Figure 4(b), the pull-out folded portion 41c cuts the base portion of the second convex 14b. As a result, the restraint force of the helical joint 12 is sequentially weakened along the winding direction from the tip side of the rehabilitation pipe 3 toward the push side (from right side to left side in Figure 5).

[0030] <Expansion Process> As shown in Figure 5, in parallel with the withdrawal of the restraint-weakening wire 41, the main-push pipe-making machine 20 (expansion pipe-making machine) feeds the trailing strip portion 19 of the strip member 10, which follows the main-push end 3e of the rehabilitated pipe 3, into the rehabilitated pipe 3 and incorporates it into the rehabilitated pipe 3. As a result, the end 3e of the rehabilitated pipe 3 is twisted, and the entire small-diameter pipe section 30, including the end 3e, is rotated as a single unit and pushed toward the tip side (right side in Figure 5). Furthermore, in the portions 32 and 33 of the rehabilitated pipe 3 where the restraint force of the helical joint 12 is weakened toward the tip side (right side in Figure 5) of the small-diameter pipe section 30, the edge portions 13 and 14 slide against each other along the winding direction, and the circumference is expanded (diameter widened). As a result, the tip end (right side in Figure 5) of the rehabilitated pipe 3 becomes a larger diameter pipe section 33 than the smaller diameter pipe section 30, and adheres to the entire circumference of the inner surface of the existing pipe 1. Between the large diameter pipe section 33 and the small diameter pipe section 30 of the rehabilitated pipe 3, there is a frustoconical cone section 32 that expands in diameter from the unexpanded small diameter pipe section 30 towards the large diameter pipe section 33. The small diameter end 32e of the cone section 32 is the same diameter as the small diameter pipe section 30 and is continuous with it. A pull-out folded-back section 41c is positioned at the small diameter end 32e. The large diameter end 32f of the cone section 32 (the end on the large diameter pipe section 33 side) is the same diameter as the large diameter pipe section 33 and is continuous with it.

[0031] Through the restraint weakening process and the expansion process, the large-diameter pipe section 33 gradually extends from the tip 3f of the rehabilitated pipe 3 toward the original pushing side (left side in Figure 5), and the cone section 32 gradually moves toward the original pushing side (left side in Figure 5). Preferably, the length of the cone section 35 along the pipe axis direction (hereinafter referred to as "cone length") L 32 The speed at which the restraint-reducing wire 41 is pulled by the winding winch 43 and the speed at which the trailing belt portion 19 is fed by the main pipe-forming machine 20 are mutually adjusted so that the size is appropriate. This prevents insufficient adhesion of the large-diameter pipe section 33 and buckling at the small-diameter end portion 32e.

[0032] As shown in Figure 6, when the distance L from the end of the main pipe-making machine 20 on the side of the starting pipe opening 1e to the large-diameter end 32f of the cone section 32 (the starting end of the large-diameter pipe section 33) is within a predetermined length, the following finishing process is performed. <Perimeter regulating body diameter expansion process (first stage diameter expansion)> The drive of the winding winch 43 and the main pipe-making machine 20 is stopped, and the restraint weakening process and expansion process are paused. Then, as shown by arrow a1 in Figure 6, the outer peripheral restrictor 21 is expanded in diameter. Specifically, as shown in Figure 2(b), the angle between the pair of arms 26a is widened by a predetermined amount by screwing in the adjustment bolt 26b of the diameter adjustment section 26 by a predetermined amount. As a result, the pair of upper quarter-circular frame sections 28 are widened by a predetermined amount, and the outer peripheral restrictor 21 is widened in diameter by Δφ1 (mm).

[0033] Preferably, the diameter expansion amount Δφ1 is limited to about a fraction of the final target diameter expansion amount Δφ0 (Δφ1 ≈ Δφ0 / n, where n is an integer of 2 or more). For example, Δφ1 = several tens of mm, preferably Δφ1 = 10 mm to 30 mm, and more preferably Δφ1 = 25 mm. This prevents the annular guide 25a (Figure 3) from coming out of the outer groove 16 and maintains the guiding function of the guide roller 25.

[0034] <Re-implementation process of restraint reduction and expansion> Next, as shown in Figure 7, the drive of the winding winch 43 and the main pipe-making machine 20 is restarted, and the restraint weakening process and the expansion process are executed again. When the expansion process is executed again, the trailing strip portion 19 of the strip member 10 is newly fed into the main pipe-making machine 20 and wound around the inner circumference of the outer peripheral restrictor 21, which has been expanded by Δφ1. As a result, the diameter of the rehabilitated pipe section 34 newly manufactured by the main pipe-making machine 20 in the rehabilitated pipe 3 becomes larger than the small-diameter pipe section 30 by Δφ1. Between the rehabilitated pipe section 34 and the small-diameter pipe section 30, a reverse-direction cone section 35 is formed, which decreases in diameter from the rehabilitated pipe section 34 towards the small-diameter pipe section 30.

[0035] As the main pipe-forming machine 20 is driven, the rehabilitated pipe section 34 extends in the pushing direction (to the right in Figure 7), and the reversed cone section 35 moves in the pushing direction (to the right in Figure 7). Simultaneously, the restraint weakening wire 41 is pulled in by the winding winch 43, causing the cone section 32 to move towards the main pushing side (to the left in Figure 7). Consequently, the small-diameter pipe section 30 shortens at twice the speed of the expansion process before the finishing treatment.

[0036] <Peripheral regulating body diameter expansion process (next stage diameter expansion)> Next, the drive of the winding winch 43 and the main pipe-making machine 20 is stopped again, and the restraint weakening process and the expansion process are paused again. Then, as shown by arrow a2 in Figure 8, the outer peripheral regulating body 21 is further expanded in the same manner as in the first stage. Preferably, the diameter is expanded by approximately the same amount Δφ2 as the expansion amount Δφ1 in the first stage (Δφ2 ≈ Δφ1).

[0037] <Re-implementation process for restraint reduction and expansion> As shown in Figure 9, the winding winch 43 and the main pipe-making machine 20 are driven again to perform the restraint weakening process and the expansion process. As a result, the diameter of the newly formed second stage rehabilitated pipe section 36 is expanded by Δφ2 compared to the first stage rehabilitated pipe section 34. Between the rehabilitated pipe sections 34 and 36, a second stage reverse cone section 37 is formed, which decreases in diameter from the rehabilitated pipe section 36 towards the rehabilitated pipe section 34.

[0038] As the main pipe-forming machine 20 is driven, the second stage rehabilitated pipe section 36 extends in the pushing direction (to the right in Figure 7), and the first stage rehabilitated pipe section 34 and the reversed cone sections 35 and 37 on both sides are moved in the pushing direction (to the right in Figure 9). Simultaneously, the cone section 32 is moved towards the main pushing side (to the left in Figure 9) by the winding winch 43 to pull in the restraining weakening wire 41, and the small diameter pipe section 30 is shortened at twice the speed of the expansion process before the finishing process.

[0039] In this way, the diameter expansion process of the outer peripheral restrictor 21 is carried out in stages in multiple steps, and restraint weakening and expansion steps are interposed between adjacent diameter expansion steps, thereby gradually expanding the diameter of the pipe portion on the push side of the rehabilitation pipe 3 to the target diameter expansion amount Δφ0. This reliably prevents the annular guide 25a from coming out of the outer peripheral groove 16 (Figure 3) and reliably maintains the guiding function of the guide roller 25. In this embodiment, the target diameter expansion amount Δφ0 is reached in two diameter expansion steps (Δφ0 = Δφ1 + Δφ2), but it is not limited to this, and the diameter expansion process may be carried out in stages over three or more steps. Furthermore, the inner diameter of the outer peripheral regulating body 21 after the final diameter expansion process is smaller than the inner diameter of the existing pipe 1. The rehabilitated pipe section 36, which has been expanded to the target diameter expansion amount Δφ0, is smaller in diameter than the large-diameter pipe section 33.

[0040] As shown in Figure 10, the cone portion 32 attaches to the first stage reverse-facing cone portion 35 through the restraint weakening and expansion process after the final diameter expansion process. The small-diameter pipe portion 30 (Figure 9) between these cone portions 32 and 35 disappears. Preferably, the cone length up to this point is a predetermined length L. 32 This is maintained. In other words, the cone length is kept to a predetermined length L until the cone section 32 merges with the reverse cone section 35 (Figure 10). 32 To ensure that the constraint weakening and expansion processes can be carried out without hindrance while maintaining the desired condition, the execution point of the first-stage diameter expansion process (Figure 6), i.e., the starting point of the finishing process, is set.

[0041] Subsequently, as the restraint weakening and expansion process continues, the cone section 32 moves further toward the original pushing side (left side in Figure 10), and as shown by the dashed line in Figure 11, the reverse-facing cone section 35, the rehabilitation pipe section 34, and the reverse-facing cone section 37 are sequentially absorbed into the cone section 32. Furthermore, as shown by the solid line in Figure 11, the smaller diameter end 32e of the cone section 32 reaches the rehabilitation pipe section 36 of the target diameter (final stage). Accordingly, the smaller diameter end 32e is gradually expanded in diameter. Cone length L 32S It becomes shorter (L 32S <L 32 ). Hereinafter, the shortened cone section 32 will be referred to as the short cone section 32S. Even though the short cone section 32S is short, the small diameter end 32e is expanded, so the cone angle can be maintained at almost the same size as the cone section 32 before it reaches the reverse cone section 35 (Figures 5 to 10). Therefore, buckling can be prevented at the small diameter end 32e of the short cone section 32S. The large diameter end 32f of the short cone section 32S can be made to adhere firmly to the inner surface of the existing pipe 1. This allows the expansion process to be carried out smoothly up to near the pipe opening 1e.

[0042] Eventually, as shown in Figure 12, the smaller diameter end 32e of the short cone section 32S appears inside the launching manhole 4 from the pipe opening 1e. Therefore, the pulled-out folded portion 41c of the restraint weakening wire 41 is positioned between the main pipe-making machine 20 and the pipe opening 1e. At this point, the winding winch 43 and the main pipe-making machine 20 are stopped, and the restraint weakening process and the expansion process are completed.

[0043] <Cutting release process> Next, as shown in Figure 13, the rehabilitated pipe 3 is cut around its entire circumference, with the cutting position P being the space between the pulled-out folded portion 41c of the restraint-weakening wire 41 and the pipe opening 1e, thereby releasing the rehabilitated pipe 3 from the main pipe-making machine 20. The released pipe end portion 31 of the rehabilitated pipe 3 is composed of a short cone portion 32S. The pipe end portion 31 is manually twisted to expand its diameter or allowed to expand naturally. Because the length of the pipe end portion 31 to be expanded, i.e., the cone length of the short cone portion 32S, is short, the workload of the worker in manually expanding the diameter can be reduced. Furthermore, the time required for manual or natural expansion can be shortened.

[0044] Subsequently, as shown in Figure 14, the pipe ends 3e and 3f of the rehabilitated pipe 3 are trimmed to be flush with the pipe openings 1e and 1f, respectively. Furthermore, the gaps between the inner circumference of pipe opening 1e and the outer circumference of pipe end 3e, and between the inner circumference of pipe opening 1f and the outer circumference of pipe end 3f are sealed with joint material 7. In this way, the rehabilitation work of the existing pipe 1 is completed.

[0045] The present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, during the finishing process, the second protrusion 14b of the trailing strip portion 19 of the strip member 10 may be pre-cut before or after introduction into the main pipe-making machine 20. When the tip of the cut mark in the rehabilitated pipe 3 merges with the pull-out folded portion 41c, the restraint weakening process and the expansion process may be terminated, and the cutting release process may be performed at the cutting position between the main pipe-making machine 20 and the pipe opening 1e. [Industrial applicability]

[0046] The present invention can be applied, for example, to the rehabilitation work of aging sewer pipes. [Explanation of Symbols]

[0047] 1 Existing pipe 1e Launch side pipe opening 1f Reach side pipe port 3 Rehabilitation pipe 3e Main push side pipe end 3f Push-in direction tip 4 Launching port 10 Strip-shaped member 12 Spiral joint 13 Edge 14 Edge 15 Ribs 16 Outer perimeter groove 19. Following section 20-Pipe Pressing Machine 21 Perimeter Regulating Body 23 Pinch Section 24 ring frame 25 Guide rollers 26 Diameter adjustment part 41 Restraint weakening wire 41c Drawer folding part 42 Reel 30 Small diameter pipe section 32 Cone section 32e Small diameter end 32f Large diameter end (end on the large diameter pipe side) 32S Short cone section 33 Large diameter pipe section

Claims

1. In an existing pipe rehabilitation method, a strip-shaped member is wound spirally along the inner circumference of an annular outer peripheral restrictor of the main pipe forming machine installed in a launching manhole connected to the existing pipe, and adjacent edges of the strip-shaped member that are one rotation apart are fitted together to form a spiral-shaped rehabilitation pipe with a diameter smaller than the inner diameter of the existing pipe, which is then pushed into the existing pipe to install the rehabilitation pipe. After the rehabilitation pipe is installed in the existing pipe, the restraining force between adjacent edges is gradually weakened along the winding direction from the leading end of the rehabilitation pipe in the pushing direction toward the main pipe forming side, and the subsequent strip portion of the strip-shaped member that follows the pipe end of the rehabilitation pipe on the main pipe forming side is sequentially fed into the rehabilitation pipe by the main pipe forming machine, thereby expanding the circumference of the portion of the rehabilitation pipe where the restraining force has been weakened and attaching it to the inner surface of the existing pipe. A method for rehabilitating an existing pipe, characterized in that when the distance from the end of the cone portion on the large-diameter pipe portion side to the main pipe-making machine is within a predetermined length, an enlargement step is performed to enlarge the outer peripheral restrictor.

2. The method for rehabilitating an existing pipe according to claim 1, wherein the diameter enlargement process of the outer circumference restricting body is carried out in stages in multiple steps.

3. A pipe-forming machine used in the existing pipe rehabilitation method according to claim 1 or 2, wherein the outer peripheral regulating body is A ring frame and A plurality of guide rollers are arranged in the circumferential direction of the annular frame and engage with the outer groove of the strip-shaped member to guide the strip-shaped member, A diameter adjustment portion is provided at one location in the circumferential direction of the annular frame and expands and contracts along the circumferential direction. A pipe-making machine characterized by being equipped with a push mechanism.

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