Method for rehabilitating an existing pipe and support jig used in the method

Abstract

To prevent expansion failure at a starting time of an expansion process of a regeneration pipe in an expander pipe-production method.SOLUTION: There is provided a regeneration method of an existing pipe, in which a helical regeneration pipe 3 made of a belt-shaped member 10 is produced to have a diameter smaller than that of an existing pipe 1 and installed in the existing pipe 1, and then a peripheral length of the regeneration pipe 3 is gradually expanded from a pipe end portion 3f side while weakening a joining force of a joining portion 15 between adjacent edges of the belt-shaped member 10. At that time, a support jig 20 is installed to the pipe end portion 3f, and a peripheral length of the pipe end portion 3f is expanded while the pipe end portion 3f is lifted from a pipe bottom 1b of the existing pipe 1 by the support jig 20.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for rehabilitating existing pipes such as aging sewer pipes and a support jig used in the method, and more particularly to a rehabilitation method and a support jig for constructing a spiral tubular rehabilitation pipe inside an existing pipe.

Background Art

[0002] There is known a method for rehabilitating an existing pipe by spirally winding a strip member (profile) along the inner circumference of the existing pipe such as an aging sewer pipe and joining adjacent edges of the strip member that are one turn apart by uneven fitting to construct a spiral tubular rehabilitation pipe (see Patent Document 1, etc.).

[0003] For example, Patent Document 1 discloses a so-called expander (expansion) pipe manufacturing method. Specifically, a push-type pipe manufacturing machine is installed in the manhole on the launching side, and while manufacturing a rehabilitation pipe with a diameter smaller than the inner diameter of the existing pipe by the pipe manufacturing machine, the rehabilitation pipe is sequentially pushed into the existing pipe from the pipe opening on the launching side of the existing pipe. During pipe manufacturing, a cutting wire is interposed at the joint of the adjacent edges of the strip member. When the tip of the rehabilitation pipe in the pushing direction reaches the pipe opening on the reaching side, the tip in the pushing direction (the pipe end on the reaching side) is fixed. Then, by pulling out the cutting wire, a part of the joint is sequentially cut from the reaching side to the launching side along the winding direction to weaken the joining force. In parallel, by further supplying the strip member from the pipe manufacturing machine, the end of the rehabilitation pipe on the pushing side (launching side) is twisted and rotated. As a result, the adjacent edges of the joint whose joining force has been weakened by the cutting slide, and the circumference of the rehabilitation pipe is sequentially expanded (diameter-expanded) from the reaching side to the launching side and attached to the inner circumferential surface of the existing pipe. A cone portion (conical portion) is formed between the small-diameter portion that has not yet been expanded and the large-diameter portion that has been expanded in the rehabilitation pipe during the expansion process.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Before the expansion process, the small-diameter rehabilitation pipe is landed on the bottom of the existing pipe, so that the pipe axis of the rehabilitation pipe is displaced downward with respect to the pipe axis of the existing pipe. In this state, when starting the circumferential expansion of the pipe end on the reaching side of the rehabilitation pipe, the pipe end is rubbed against the bottom of the existing pipe, resulting in poor expansion (diameter expansion failure), and the cross-section of the rehabilitation pipe may be distorted into, for example, a horizontally long elliptical shape, or the length, taper angle, or shape of the cone portion may change. In some cases, breakage (back buckling) of the joint portion at the small-diameter side end of the cone portion or insufficient adhesion at the large-diameter side end of the cone portion may also occur. In view of such circumstances, an object of the present invention is to prevent the occurrence of poor expansion, particularly at the start of the expansion process, in the expandable pipe manufacturing method.

Means for Solving the Problems

[0006] To solve the above problems, the method of the present invention is to manufacture a spiral tubular rehabilitation pipe by spirally winding a belt-like member and joining adjacent edges with one turn difference, install it in the existing pipe with a smaller diameter than the inner diameter of the existing pipe, and then pull a cutting wire interposed at the joint of the adjacent edges from one side to the other side in the pipe axis direction of the rehabilitation pipe, sequentially cutting a part of the joint along the winding direction to weaken the joining force, and twisting the other side part of the rehabilitation pipe to expand the circumference of the weakened part of the rehabilitation pipe. It is a method for rehabilitating an existing pipe, After the installation and before the expansion, a support jig is attached to the pipe end on the one side of the rehabilitation pipe, Characterized in that the expansion of the pipe end is performed in a state where the pipe end is lifted from the bottom of the existing pipe by the support jig.

[0007] According to this method, by floating one end of the rehabilitation pipe, the end of the pipe can be well expanded in circumference (diameter expansion) while not rubbing against the bottom of the existing pipe. Thereby, it is possible to prevent the cross-section of the pipe end from being distorted. Also, by appropriately maintaining the length, taper angle, and shape of the cone portion, it is possible to prevent the joints between adjacent edges of the belt-like members at the pipe end from breaking or insufficient adhesion from occurring. When twisting and rotating the other side portion of the rehabilitation pipe, since the support jig can prevent the pipe end from rotating, the joint force weakening portion can be reliably expanded in circumference. After the end of the rehabilitation pipe adheres to the inner circumference of the existing pipe, the unexpanded portion following the pipe end receives an upward force from the pipe end and is expanded in circumference while floating from the bottom of the existing pipe. Thereby, the rehabilitation pipe can be well expanded into a pipe over the entire area.

[0008] It is preferable to perform the expansion of the pipe end in a state where the pipe end is axially aligned with the existing pipe by the support jig. Thereby, one end of the rehabilitation pipe is expanded in circumference while maintaining a concentric state with respect to the existing pipe. Therefore, it is possible to prevent the pipe end during expansion from contacting and rubbing against the inner surface of the existing pipe. Thereby, it is possible to more reliably prevent poor expansion of the pipe end from occurring. The axially aligned state does not necessarily mean that the pipe axis of the pipe end exactly coincides with the pipe axis of the existing pipe, and it is sufficient that the pipe axes are approximately coincident by visual inspection or the like. Alternatively, the eccentricity of the pipe axis of the pipe end with respect to the pipe axis of the existing pipe may be preferably within 20%, more preferably within 10% of the inner diameter of the existing pipe.

[0009] The support jig includes an engaging portion engaged with the pipe end and a support means for supporting the engaging portion, and it is preferable that the supporting force for floating the pipe end is applied from the support means to the pipe end through the engaging portion. By using the support jig, the end of the rehabilitation pipe during the expansion process can be well expanded in circumference while preventing it from rubbing against the bottom of the existing pipe.

[0010] Preferably, the supporting means includes a rod-shaped body extending outward to the outside of the pipe and intersecting with the circumferential direction of the pipe end portion, and the engaging portion is provided at the intersecting portion of the rod-shaped body and the pipe end portion. This enables the support jig to have a simple structure.

[0011] Preferably, the engaging portion includes a clamp that sandwiches the pipe end portion from the outer peripheral side and the inner peripheral side. This enables the pipe end portion to be firmly fixed to the support jig. Preferably, the rod-shaped body is disposed outside the pipe end portion in the axial direction of the rehabilitation pipe, and the clamp is preferably inserted into the outer peripheral side and the inner peripheral side of the pipe end portion from the outside in the axial direction of the rehabilitation pipe. This eliminates the need to form a through hole through which the support jig is inserted into the pipe end portion. A through hole may be formed in the pipe end portion, and the support jig may be inserted into the through hole and engaged with the pipe end portion.

[0012] Preferably, the end portion of the rod-shaped body on the outside of the pipe constitutes a grip portion that can be gripped by a person. This further simplifies the structure of the support jig. This structure is suitable when the pipe end portion is lightweight. By the operator gripping the grip portion and lifting the rod-shaped body, the pipe end portion can be manually lifted from the bottom of the existing pipe. Even when the weight of the pipe end portion is somewhat large, by using the rod-shaped body as a lever, providing a fulcrum in the end portion space (manhole, etc.) on one side of the existing pipe, supporting the middle portion of the rod-shaped body with the fulcrum, using the engaging portion as the point of application of force, and the grip portion as the point of force, the human force can be amplified to lift the pipe end portion.

[0013] Preferably, the supporting means includes a support base installed in the end portion space on one side of the existing pipe, the engaging portion includes an engaging arm horizontally supported by the support base, and the engaging arm preferably penetrates the side portion of the pipe end portion. By adjusting the support height of the engagement arm with the support base, the pipe end can be lifted from the bottom of the existing pipe. Preferably, the pipe axis height of the pipe end can be made substantially the same as that of the existing pipe. Further, by adjusting the position of the pipe end horizontally along the engagement arm, the pipe end can be aligned with the existing pipe. When the engagement arm is engaged with the pipe end, the pipe end can be prevented from rotating when the other side portion of the rehabilitation pipe is twisted and rotated. Therefore, the pipe end can be reliably expanded in circumference.

[0014] Preferably, the engagement arm penetrates the side portion of the pipe end where the torsional force acts downward among the side portions on both sides of the pipe end. As a result, when the other side portion of the rehabilitation pipe is twisted and rotated, an upward reaction force is applied to the pipe end from the engagement arm. Thereby, the pipe end can be reliably lifted from the bottom of the existing pipe.

Advantages of the Invention

[0015] According to the present invention, in the expandable pipe manufacturing method, it is possible to prevent the occurrence of expansion defects at the start of the expansion process of the rehabilitation pipe.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <First Embodiment (FIGS. 1 to 6)> <Existing Pipe 1 and Rehabilitation Pipe 3> As shown in FIGS. 1 and 6, the existing pipe 1 is rehabilitated by lining the rehabilitation pipe 3 on the inner circumference of the aged existing pipe 1. The existing pipe 1 to be rehabilitated is, for example, a sewer pipe buried underground, but the present invention is not limited to this, and it may be a water supply pipe, an agricultural water pipe, a gas pipe, a water conduit for hydropower generation, a tunnel, or the like. Both ends of the existing pipe 1 are connected to manholes 4 and 4B.

[0018] <Band-shaped Member 10> As shown in Fig. 3(a), the rehabilitation pipe 3 is composed of a strip member 10 (profile). The strip member 10 is made of a synthetic resin such as polyvinyl chloride (PVC) and is formed into a certain cross-sectional shape. Male and female fitting portions 13 and 14 are provided at both edges in the width direction of the strip member 10.

[0019] <Existing pipe rehabilitation method> The existing pipe 1 is rehabilitated as follows. <Pipe manufacturing process> As shown in Fig. 1, a mandrel-type pipe manufacturing machine 8 is prepared and installed in the manhole 4 on the launching side. The strip member 10 is sequentially unwound from the drum 7 on the ground and supplied to the pipe manufacturing machine 8. In the pipe manufacturing machine 8, the strip member 10 is wound spirally, and the adjacent fitting portions 13 and 14 with a one-week difference are joined by concave-convex fitting (Fig. 3(a)), and the rehabilitation pipes 3 are sequentially manufactured. The joining portion 15 is formed by the concave-convex fitting portions 13 and 14. At this time, the rehabilitation pipe 3 has a smaller diameter than the inner diameter of the existing pipe. The manufactured rehabilitation pipe 3 is sequentially pushed into the existing pipe 1 by the mandrel-type pipe manufacturing machine 8.

[0020] <Process with cutting wire interposed> As shown in Fig. 1, during the pipe manufacturing process, a cutting wire 41 is introduced from the wire pay-out roll 42 to the pipe manufacturing machine 8 and interposed between the fitting portions 13 and 14 of the joining portion 15 (Fig. 3(a)).

[0021] <Rehabilitation pipe installation process> As shown in Fig. 1, in this way, the pipe manufacturing of the rehabilitation pipe 3 is carried out until the pipe end portion 3f on the reaching side (one side) of the rehabilitation pipe 3 protrudes slightly from the pipe opening 1f on the reaching side (right in Fig. 1) of the existing pipe 1 to the manhole 4B on the reaching side. Thereby, the rehabilitation pipe 3 is installed over the entire area of the existing pipe 1. In this specification, the pipe end portion 3f includes the portion disposed inside the existing pipe opening 1f in the rehabilitation pipe 3 and the portion protruding to the manhole 4B.

[0022] As shown in FIGS. 1 and 2, at this stage, the rehabilitation pipe 3 is entirely an unexpanded pipe portion 3a with a smaller diameter than the existing pipe 1, and is landed on the pipe bottom 1b of the existing pipe 1. The pipe axis of the rehabilitation pipe 3 is eccentric downward with respect to the pipe axis of the existing pipe 1. Further, as shown in FIGS. 1 and 3(a), the cutting wire 41 is spirally wound along the belt-like member 10 in a state of being accommodated in the joint portion 1 over the entire area of the rehabilitation pipe 3.

[0023] As shown in FIG. 1, further, the cutting wire 41 is drawn out from the pipe end portion 3f on the arrival side (one side) of the rehabilitation pipe 3 and folded back toward the departure side (the other side). A folded-back portion 41c of the cutting wire 41 is formed at the pipe end portion 3f. The drawn-out portion 41b on the tip side from the folded-back portion 41c in the cutting wire 41 is wound around a wire take-up winch 43 installed in the departure-side manhole 4 through the inside of the rehabilitation pipe 3.

[0024] <Support jig installation process> As shown in FIG. 1, a support jig 20 is attached to the pipe end portion 3f of the unexpanded rehabilitation pipe 3 after the installation. As shown in FIG. 2, the support jig 20 includes a rod-shaped body 21 (support means) and a clamp 22 (engagement portion). One end of the rod-shaped body 21 intersects the circumferential direction of the pipe end portion 3f, and the other end is directed to extend outside the pipe. A clamp 22 is provided at one end (the intersection portion with the pipe end portion 3f) of the rod-shaped body 21. The clamp 22 has a pair of clamp members 22a, 22b. The end portion outside the pipe in the rod-shaped body 21 constitutes a grip portion 21b that can be gripped by a person. Thereby, the support jig 20 can have a simple structure.

[0025] As shown by the two-dot chain line in Fig. 1, the rod-shaped body 21 of the support jig 20 is brought close to the pipe end portion 3f from the outside in the pipe axis direction (the right side in Fig. 1) of the pipe end portion 3f, and the pair of clamp members 22a, 22b of the clamp 22 are inserted into the outer peripheral side and the inner peripheral side of the pipe end portion 3f from the outside in the pipe axis direction. By these clamp members 22a, 22b, one location of the pipe end portion 3f is strongly clamped from the outer peripheral side and the inner peripheral side. Thereby, the clamp 22 is fixed (engaged) to the pipe end portion 3f. Also, by holding the rod-shaped body 21, the pipe end portion 3f is prevented from rotating.

[0026] <Lifting process, axial alignment process> As shown in Figs. 4 and 5, further, an operator (not shown) holds the gripping portion 21b, lifts the rod-shaped body 21, and lifts the pipe end portion 3f from the pipe bottom 1b of the existing pipe 1. In other words, the supporting force for lifting the pipe end portion 3f is applied to the pipe end portion 3f from the rod-shaped body 21 (supporting means) via the clamp 22 (engaging portion). Preferably, the pipe axis of the pipe end portion 3f is axially aligned so as to be substantially coincident with the pipe axis of the existing pipe 1. This structure is suitable when the pipe end portion 3f is lightweight enough to be lifted manually.

[0027] Even when the weight of the pipe end portion 3f is somewhat large, by constructing a lever with the rod-shaped body 21, the human power can be amplified to lift the pipe end portion 3f. The pipe end portion 3f may be lifted by supporting the rod-shaped body 21 so as to be liftable by a lifting support mechanism such as a jack.

[0028] <Expansion process> While maintaining the floating state of the pipe end portion 3f, the expansion process is started. Specifically, as shown in FIG. 4, the wire take-up winch 43 is driven to take up the drawn-out portion 41b of the cutting wire 41 from the reaching side (one side, the right side in FIG. 4) to the starting side (the other side, the left side in FIG. 4). As a result, the folded-back portion 41c is spirally shifted toward the starting-side pipe end portion 3e along the winding direction of the regeneration pipe 3. As shown in FIG. 3(b), at this time, a part of the ridges 14b (a part of the joint portion 15) in the male fitting portion 14 is cut off from the root portion by the folded-back portion 41c. Therefore, the engaging force (constraining force) between the fitting portions 13 and 14 in the joint portion 15 is weakened. That is, the engaging force is weakened. As a result, the fitting portions 13 and 14 can slide relative to each other in the winding direction. As the folded-back portion 41c moves toward the starting side, the ridges 14b are sequentially cut along the winding direction, and the range where the engaging force is weakened spreads toward the starting side.

[0029] As shown in FIG. 4, in parallel with the taking-up of the cutting wire 41, the original pressing pipe making machine 8 is driven to further supply the belt-like member 10 to the regeneration pipe 3. As a result, a torsional force is applied to the starting-side pipe end portion 3e (the portion on the other side) of the regeneration pipe 3, and the small-diameter unexpanded pipe portion 3a from the starting-side pipe end portion 3e to the folded-back portion 41c is rotated. In the portion of the regeneration pipe 3 from the folded-back portion 41c to the reaching-side pipe end portion 3f where the engaging force is weakened, the fitting portions 13 and 14 of the joint portion 15 slide relative to each other in the winding direction, and the circumferential length is sequentially expanded (the diameter is increased). Since the pipe end portion 3f is prevented from rotating by the support jig 20, the expansion action can be surely caused.

[0030] As shown in FIG. 5, since the pipe end portion 3f is lifted from the pipe bottom 1b of the existing pipe 1 by the support jig 20, it is possible to avoid the pipe end portion 3f rubbing against the pipe bottom 1b of the existing pipe 1 during expansion. As a result, it is possible to prevent the occurrence of expansion defects such as the cross section of the pipe end portion 3f being distorted into, for example, a horizontally long elliptical shape.

[0031] Preferably, since the pipe end portion 3f is axially aligned with the existing pipe 1 by the support jig 20, as shown by the two-dot chain line in FIG. 5, while maintaining a concentric circular cross-section with respect to the existing pipe 1, it can be circumferentially expanded (diameter-expanded). Therefore, during the circumferential expansion, it is possible to avoid the pipe end portion 3f from coming into contact with and rubbing against not only the pipe bottom 1b of the existing pipe 1 but also various locations on the inner peripheral surface of the existing pipe 1. As a result, it is possible to more reliably prevent the occurrence of poor expansion of the pipe end portion 3f.

[0032] As shown by the two-dot chain line in FIG. 5, as the pipe end portion 3f is circumferentially expanded, the support jig 20 is raised. By this, it is possible to surely prevent the pipe end portion 3f from rubbing against the pipe bottom 1b of the existing pipe 1 even when the pipe end portion 3f is circumferentially expanded, and furthermore, it is possible to surely maintain the axial alignment state with the existing pipe 1 even when the pipe end portion 3f is circumferentially expanded. As a result, as shown by the three-dot chain line in FIG. 5, it is possible to expand the circumference well until the pipe end portion 3f adheres to the inner peripheral surface of the existing pipe 1 over the entire circumference.

[0033] As shown in FIG. 6, the rehabilitation pipe 3 is formed with a cone portion 3c that expands in diameter from the folded-back portion 41c toward the pipe end portion 3f. Since the pipe end portion 3f is expanded well, the length, inclination angle, shape, etc. of the subsequent cone portion 3c can be maintained well. Therefore, it is possible to prevent the joint portion 15 from being broken at the small-diameter side end portion 3ca of the cone portion 3c, or the insufficient adhesion of the large-diameter side end portion 3cb of the cone portion 3c to the existing pipe 1.

[0034] The rehabilitation pipe 3 is sequentially circumferentially expanded from the arrival side toward the pipe end portion 3e on the departure side. Since the expanded pipe portion on the arrival side in the rehabilitation pipe 3 is circumferentially expanded well and adhered to the inner circumference of the existing pipe 1, the subsequent unexpanded portion 3a receives an upward force from the expanded pipe portion and floats from the pipe bottom 1b of the existing pipe 1, and is circumferentially expanded well. In this way, as shown by the two-dot chain line in FIG. 6, it is possible to expand the circumference well up to the end portion on the departure side of the rehabilitation pipe 3, and it is possible to adhere the entire area of the rehabilitation pipe 3 to the inner peripheral surface of the existing pipe 1.

[0035] Next, another embodiment of the present invention will be described. Regarding the configurations that overlap with those already described in the following embodiments, the same reference numerals will be given in the drawings and the description will be omitted. <Second Embodiment (Figs. 7 to 8)> As shown in Figs. 7 and 8, the support jig 30 in the second embodiment of the present invention includes inner and outer support bases 31, 32 (support means) and an engagement arm 33 (engagement portion). The support bases 31, 32 are installed in the access manhole 4B on the reach side (the end space on one side of the existing pipe). The inner support base 31 has a support column 34 and a support beam 35. As shown in Fig. 7, the support column 34 is erected in the access manhole 4B on the reach side. As shown in Fig. 8, the support beam 35 extends horizontally from the upper end of the support column 34. The support beam 35 is inserted into the pipe end portion 3f of the rehabilitation pipe 3.

[0036] As shown in Fig. 8, an outer support base 32 is provided on the inner wall of the access manhole 4B on the reach side on the side of the pipe end portion 3f protruding from the pipe mouth 1f. The outer support base 32 is composed of, for example, a timber such as a square timber, but is not limited thereto, and may be composed of a metal material, or a component of the manhole 4B itself such as an invert may be substituted as the outer support base.

[0037] An engagement hole 3h is formed through the side portion 3s of the pipe end portion 3f. As shown in Fig. 7, preferably, the engagement hole 3h is arranged in the side portion 3s on the side where the torsional force a during the expansion process acts downward among the side portions on both sides of the pipe end portion 3f. More preferably, the engagement hole 3h is formed avoiding the joint portion 15 between the fitting portions 13, 14 (see Fig. 3).

[0038] The engagement arm 33 is formed with a circular cross-section and extends straight horizontally. As shown in Figs. 7 and 8, the engagement arm 33 passes through the engagement hole 3h and penetrates the side portion 3s of the pipe end portion 3f. The inner end of the engagement arm 33 inside the pipe end portion 3f is joined to the tip of the support beam 35 of the inner support base 31. The outer end of the engagement arm 33 outside the pipe end portion 3f is placed on the outer support base 32. Thereby, the engagement arm 33 is bridged between the inner support base 31 and the outer support base 32 and is supported horizontally.

[0039] As shown in FIG. 7, the pipe end portion 3f before the expansion process is suspended and supported by the engagement arm 33. Thereby, the pipe end portion 3f can be lifted from the bottom of the existing pipe 1. The engagement arm 33 constitutes an engagement portion with the pipe end portion 3f. In particular, it constitutes an engagement portion with the side portion 3s on which the torsional force a during the expansion process acts downward. The support bases 31 and 32 constitute a support means for applying a support force to the pipe end portion 3f through the engagement arm 33 to lift and support the pipe end portion 3f from the bottom of the existing pipe 1.

[0040] Preferably, the support height of the engagement arm 33 by the support bases 31 and 32 is adjusted. The support column 34 may be telescopic, or a pedestal for height adjustment may be placed at the bottom of the support column 34. The thickness or the installation height of the support base 32 may be adjusted. Thereby, the pipe end portion 3f can be surely lifted from the bottom 1b of the existing pipe 1. Furthermore, the pipe axis height of the pipe end portion 3f can be made substantially coincide with the pipe axis height of the existing pipe 1. Furthermore, the pipe end portion 3f is horizontally position-adjusted along the engagement arm 33. Thereby, the pipe axis of the pipe end portion 3f can be made substantially coincide with the pipe axis of the existing pipe 1. Thereby, the expansion process can be performed with the pipe end portion 3f aligned with the existing pipe 1, and the circumferential expansion can be performed well.

[0041] The torsional force a during the expansion process acts downward on the side portion 3s. This is received by the engagement arm 33. Thereby, an upward reaction force against the torsional force is applied to the pipe end portion 3f from the engagement arm 33. Thereby, the circumferential expansion can be performed in a state where the pipe end portion 3f is surely lifted from the bottom 1b of the existing pipe 1.

[0042] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit thereof. For example, at least from the start to the middle stage of the expansion process of the pipe end portion 3f, it is sufficient that the pipe end portion 3f floats from the bottom 1b of the existing pipe 1, and it is not necessarily required that the pipe end portion 3f is aligned with the existing pipe 1. It is preferable that the pipe end 3f is always separated from the pipe bottom 1b of the existing pipe 1 at least from the start to the middle of the expansion process, but in cases where the burden of lifting it by manual force is large, it does not need to be always separated, and the pipe end 3f and the existing pipe 1 may be in contact to the extent that the frictional resistance is smaller than at the beginning and no poor expansion occurs. As shown in Figures 9 and 10, as a modified version of the first embodiment, one end (lower end) of the rod-shaped body 21 may be abutted against the lower half of the inner surface of the existing pipe 1 (Figure 9) or the bottom surface of the manhole 4B (Figure 10) to obtain a reaction force, and the pipe end 3f may be lifted using the principle of leverage. As a modification of the first embodiment, the rod-shaped body may penetrate the tube end and engage with the tube end. An engagement hole may be formed at one location on the tube end. The engagement portion may be inserted into the engagement hole to engage with the tube end. The support means of the support jig may include a jack that lifts up the engagement portion and thus the pipe end portion. [Industrial Applicability]

[0043] The present invention can be applied, for example, to the rehabilitation of deteriorated sewer pipes. [Explanation of symbols]

[0044] 1 Existing pipes 1b Tube bottom 1f Entry side pipe 3 Rehabilitation pipe 3a Unexpanded pipe section 3c Cone part 3ca Small diameter end 3cb Large diameter end 3e Starting pipe end (other side part) 3f End of pipe on the arrival side (one side) 3h Engagement hole 3s Side part where torsional force is applied downward 4. Starting manhole 4B Arrival side manhole (space at one end of existing pipe) 8. Push-type pipe making machine 10 Belt-shaped member 13 Female mating part 14 Male fitting part 15 Joint part 20 Support jig 21 Rod-shaped body (support means) 21a Pipe engagement side end 21b Gripping part 22 Clamp (engagement part) 22a Clamp member 22b Clamp member 30 Support jig 31 Inner support base (support means) 32 Outer support base (support means) 33 Engagement arm (engagement part) 34 Support column 35 Support beam 41 Cutting wire 41b Pulled-out part 41c Folded-back part 42 Wire payout roll 43 Wire take-up winch

Claims

Claim 1: A spiral tubular rehabilitation pipe formed by spirally winding a strip-shaped member and joining adjacent edges that are one turn different, is manufactured to have a smaller diameter than the inner diameter of an existing pipe and installed inside the existing pipe. After that, a cutting wire interposed at the joint of the adjacent edges is pulled from one side to the other side in the pipe axis direction of the rehabilitation pipe, sequentially cutting a part of the joint along the winding direction to weaken the joining force, and twisting the other side portion of the rehabilitation pipe to expand the circumference of the weakened portion of the rehabilitation pipe. It is used in a method for rehabilitating an existing pipe and is a support jig attached to the pipe end portion on one side of the rehabilitation pipe after installation and before expansion, an engaging portion engaged with the pipe end portion, support means for supporting the engaging portion, and is characterized in that the support means includes a rod-shaped body extending outward from the pipe and intersecting the circumferential direction of the pipe end portion, and the engaging portion is provided at the intersection of the rod-shaped body and the pipe end portion. Claim 2 The support jig according to claim 1, wherein the end portion of the rod-shaped body outside the pipe constitutes a grip portion that can be gripped by a person. Claim 3: A spiral tubular rehabilitation pipe formed by spirally winding a strip-shaped member and joining adjacent edges that are one turn different, is manufactured to have a smaller diameter than the inner diameter of an existing pipe and installed inside the existing pipe. After that, a cutting wire interposed at the joint of the adjacent edges is pulled from one side to the other side in the pipe axis direction of the rehabilitation pipe, sequentially cutting a part of the joint along the winding direction to weaken the joining force, and twisting the other side portion of the rehabilitation pipe to expand the circumference of the weakened portion of the rehabilitation pipe. It is used in a method for rehabilitating an existing pipe and is a support jig attached to the pipe end portion on one side of the rehabilitation pipe after installation and before expansion, an engaging portion engaged with the pipe end portion, support means for supporting the engaging portion, and is characterized in that the engaging portion includes a clamp that sandwiches the pipe end portion from the outer peripheral side and the inner peripheral side.

4. A spiral tubular rehabilitation pipe formed by spirally winding a strip-shaped member and joining adjacent edges with one turn difference is manufactured to have a smaller diameter than the inner diameter of an existing pipe and installed inside the existing pipe. After that, a cutting wire interposed at the joint of the adjacent edges is pulled from one side to the other side in the pipe axis direction of the rehabilitation pipe, sequentially cutting a part of the joint along the winding direction to weaken the joining force, and twisting the other side part of the rehabilitation pipe to expand the circumference of the weakened part of the rehabilitation pipe. It is used in a method for rehabilitating an existing pipe, and is a support jig attached to the pipe end on one side of the unexpanded rehabilitation pipe after the installation, an engaging portion engaged with the pipe end portion, support means for supporting the engaging portion, and is provided with the support means including a support base installed in the end space on one side of the existing pipe, the engaging portion including an engaging arm horizontally supported by the support base, and the engaging arm penetrating the side portion of the pipe end portion. A support jig characterized by

5. The support jig according to claim 4, wherein the engaging arm penetrates the side portion of the pipe end portion on the side where the torsional force acts downward among the side portions on both sides of the pipe end portion.

6. The rehabilitation method using the support jig according to any one of claims 1 to 5, wherein a support jig is attached to the pipe end on one side of the unexpanded rehabilitation pipe after the installation, and the expansion of the pipe end portion is performed in a state where the pipe end portion is floated from the bottom of the existing pipe by the support jig. A method for rehabilitating an existing pipe characterized by

7. The method for rehabilitating an existing pipe according to claim 6, wherein the expansion of the pipe end portion is performed in a state where the pipe end portion is axially aligned with the existing pipe by the support jig.

Images