Corrugated pipe repair method, repair fitting set, and pipe structure

Abstract

To provide a repair method of a corrugated pipe which can repair a repair point of the corrugated pipe by easy work.SOLUTION: A repair method of a corrugated pipe 10 having a repair point between a first large-diameter part 11A and a second large-diameter part 11B has: a first step for arranging a first trough filling material 30A at an external periphery of a small-diameter part 12A which adjoins the first large-diameter part 11A; a second step for arranging a second trough filling material 30B at an external periphery of a small-diameter part 12B adjoining the second large-diameter part 11B; a third step for arranging first seal parts 40A at external peripheries of the first large-diameter part 11A and the first trough filling material 30A; a fourth step for arranging second seal parts 40B at external peripheries of the second large-diameter part 11B and the second trough filling material 30B; and a fifth step for attaching a repair joint 20 so as to cover the first seal part 40A and the second seal part 40B.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a repair method for corrugated pipes used for cable protection pipes and the like, a repair joint set, and a pipe structure.

Background Art

[0002] For purposes such as improving urban landscapes, cables such as electric wires and optical fibers are buried underground, and in order to protect these cables, the cables are inserted into cable protection pipes buried underground. Such cable protection pipes are mixed with water pipes, gas pipes, etc. underground, and may be damaged by heavy machinery or the like during construction work on water pipes, gas pipes, etc.

[0003] As a repair method for cylindrical cable protection pipes, as shown in Non-Patent Document 1, a method using a half-split cover is known. For example, in the case of small-scale damage to a cable protection pipe, a half-split cover cut into a predetermined size is fixed with an adhesive over the damaged portion where an opening is cut out in the cable protection pipe. In the case of large-scale damage to a cable protection pipe, the pipe portion including the damaged portion is removed, and both cut ends are connected by a pair of half-split covers and fixed with an adhesive.

[0004] On the other hand, Patent Document 1 discloses a branching method for a conduit (cable protection pipe) using a cable extraction protection member composed of a pair of half-cylindrical members having a branching portion. In particular, FIGS. 8 to 13 of the patent document disclose a branching method for a rectangular conduit in which large-diameter portions having a substantially square cross-section and small-diameter portions having a substantially circular cross-section are alternately formed. This cable extraction protection member is formed with a front cylindrical portion, an intermediate cylindrical portion, and a rear cylindrical portion in this order. The end of one conduit is fitted into the front cylindrical portion, the end of the other conduit is fitted into the rear cylindrical portion, and a branching portion is provided on the intermediate cylindrical portion. Patent Document 2 also discloses a repair method in which the damaged portion of an outer pipe having reinforcing ribs formed at a constant pitch in the pipe axial direction on the outer peripheral surface is cut, and the cut portion is connected by a half-split repair joint 1. Furthermore, a method is disclosed in which an O-ring is sandwiched between the reinforcing ribs of the outer pipe to provide a seal between the outer pipe and the half-split repair joint. Furthermore, Patent Document 3 discloses a method for repairing a damaged portion of a spiral pipe by attaching a halved repair device near the repair area without cutting the spiral pipe. The repair device comprises a repair outer cylinder member consisting of a pair of repair outer cylinder halves and a sealing member consisting of a pair of sealing halves. The sealing halves are pressed onto the outer circumference of the spiral pipe, spanning multiple spiral grooves. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Tokyo Metropolitan Electric Wire Common Ditch Maintenance Manual, Reference Material “Construction Procedures”, April 2020, pages 12 to 14 [Patent Documents]

[0006] [Patent Document 1] Patent No. 6858291 [Patent Document 2] Japanese Patent Publication No. 2002-171630 [Patent Document 3] Japanese Patent Publication No. 2000-336703 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the repair method described in Non-Patent Document 1 is intended for cylindrical cable protection tubes with a uniform outer surface, and a sufficient sealing (adhesion) area is secured between the split cover and the cable protection tube with adhesive. Therefore, even if the repair method described in Non-Patent Document 1 is applied to a corrugated tube with irregularities on its outer surface, it is not possible to secure a sufficient sealing area between the corrugated tube and the split cover. To secure a sufficient sealing area, a long split cover would be required. Furthermore, even if the same total sealing area could be secured, multiple independent sealing regions would be formed in the longitudinal direction, and it would not be possible to obtain the same sealing performance as a cylindrical cable protection tube. In addition, it would be necessary to prepare appropriate types of adhesives depending on the materials of the split cover and the cable protection tube. Furthermore, the cable outlet protection member described in Patent Document 1 involves fitting the large-diameter section of one rectangular conduit to the front cylindrical section, and fitting the large-diameter section of the other rectangular conduit to the rear cylindrical section. Therefore, it is necessary to precisely match the distance between the rectangular conduits on both sides, which makes the work at the site complicated. Furthermore, Patent Document 2 describes sealing the space between the outer pipe and the half-split repair joint by inserting an O-ring between the reinforcing ribs of the outer pipe, but even in this case, it is not possible to secure a sufficient sealing area. Furthermore, Patent Document 3 ensures sealing performance by pressing the sealing member into the groove of the spiral pipe. In other words, the sealing performance can easily vary depending on how the halved sealing member and the spiral pipe are attached, making the work complicated. This invention was researched and developed in consideration of these circumstances, and aims to provide a simple method for repairing corrugated pipes, a repair joint set, and a pipe structure formed by this method. [Means for solving the problem]

[0008] The present invention relates to a corrugated pipe repair method, which is a corrugated pipe made of synthetic resin having alternating large-diameter and small-diameter sections in the longitudinal direction, and having a repair area between a first large-diameter section and a second large-diameter section, and is characterized by comprising the steps of: providing a first valley-filling material on the outer circumference of a small-diameter section adjacent to the first large-diameter section; providing a second valley-filling material on the outer circumference of a small-diameter section adjacent to the second large-diameter section; providing a first seal portion on the outer circumference of the first large-diameter section and the outer circumference of the first valley-filling material; providing a second seal portion on the outer circumference of the second large-diameter section and the outer circumference of the second valley-filling material; and covering the first seal portion and the second seal portion with a cylindrical repair joint composed of a plurality of radially divided sections.

[0009] The corrugated pipe repair method of the present invention provides valley-filling material on the outer circumference of the small-diameter portion adjacent to the first large-diameter portion on the side to be repaired, and the small-diameter portion adjacent to the second large-diameter portion on the side to be repaired. In other words, a first seal portion is provided so as to straddle the space between the first large-diameter portion and the first valley-filling material, and a second seal portion is provided so as to straddle the space between the second large-diameter portion and the second valley-filling material. This ensures a sufficient contact area to seal the space between the corrugated pipe and the repair joint. Therefore, watertightness between the corrugated pipe and the repair joint can be ensured. Furthermore, assembling the repair joint to the corrugated pipe only requires covering the first and second seal sections with the repair joint, and the repair work can be easily performed whether the corrugated pipe is cut and the section to be repaired is removed, or whether the section to be repaired is removed without cutting the corrugated pipe. Furthermore, even if a single corrugated pipe has multiple repair areas, each repair area can be given the same level of watertightness and resistance to flattening against soil pressure as the pipe's connection points, thus maintaining the overall performance of protecting the cable.

[0010] The present invention relates to a method for repairing a corrugated pipe, wherein the first large-diameter portion and the second large-diameter portion are continuous in at least a portion thereof, and the repair joint covers the first seal portion, the second seal portion, and the portion to be repaired between them. Here, "the first large-diameter portion and the second large-diameter portion are continuous in at least a portion thereof" means that the corrugated pipe is repaired without cutting it. When the repair joint is attached to the corrugated pipe without cutting it in this way, even if an external force that causes the repaired area to bend is applied to the pipe structure after repair, stress is less likely to concentrate at the connection portion between the repair joint and the corrugated pipe because the corrugated pipe is continuous, and as a result the overall strength is maintained. The present invention relates to a method for repairing corrugated pipes, wherein it is preferable that a branching cylinder is provided in at least one segment of the repair joint. In this case, the opening portion formed in the corrugated pipe by the branching becomes the repair area according to the present invention. The method for repairing corrugated pipes according to the present invention is also suitable for branching work on existing corrugated pipes.

[0011] The repair joint set of the present invention is used for repairing a corrugated pipe made of synthetic resin, which has large-diameter and small-diameter sections arranged alternately in the longitudinal direction, with a repair area between the first large-diameter section and the second large-diameter section. The repair joint set comprises two valley-filling materials provided on the outer circumference of the small-diameter section, a cylindrical repair joint composed of a plurality of radially divided sections for covering the first and second large-diameter sections, and a sealing portion provided between the corrugated pipe and the repair joint. The valley-filling material is annular in shape with a central hole having substantially the same diameter as the outer diameter of the small-diameter section, and is characterized in that a cutting line is formed from the outer surface toward the central hole. By using this repair joint set, the corrugated pipe repair method of the present invention can be preferably carried out. In such a repair joint set, it is preferable that a branching pipe is provided on at least one segment of the repair joint.

[0012] The pipe structure of the present invention comprises a corrugated resin pipe having large-diameter and small-diameter sections alternately arranged in the longitudinal direction, and a cylindrical repair joint composed of a plurality of sections divided radially, wherein the repaired section between the first large-diameter section and the second large-diameter section of the corrugated pipe is repaired with the repair joint, and the repair joint has a first valley filler provided on the outer circumference of the small-diameter section adjacent to the first large-diameter section, a second valley filler provided on the outer circumference of the small-diameter section adjacent to the second large-diameter section, a first seal section provided on the outer circumference of the first large-diameter section and the outer circumference of the first valley filler, and a second seal section provided on the outer circumference of the second large-diameter section and the outer circumference of the second valley filler, and the repair joint is provided so as to cover the first seal section and the second seal section. In the pipe structure of the present invention, it is preferable that the first large-diameter portion and the second large-diameter portion are continuous in at least a part thereof, and the first sealing portion, the second sealing portion, and the portion to be repaired between them are covered by the repair joint. In the pipe structure of the present invention, it is preferable that a branching cylinder is provided in at least one segment of the repair joint. [Effects of the Invention]

[0013] According to the corrugated pipe repairing method of the present invention, repairing work on a repaired portion such as a damaged portion caused by excavation work or the like and an opening formed for branching can be easily performed on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [Figure 1] Figs. 1a and 1b are respectively a side cross-sectional view showing a part of a first embodiment of the pipe structure of the present invention and a cross-sectional view taken along line X-X thereof, and Fig. 1c is a partially enlarged view of Fig. 1a. [Figure 2] Figs. 2a and 2b are respectively a side view and a front view of a repair joint of the pipe structure in Fig. 1, Figs. 2c and 2d are a plan view and a front view of a divided body of the repair joint, Fig. 2e is a front view of a valley filling material of the pipe structure in Fig. 1, and Fig. 2f is a plan view showing another embodiment of the divided body of the repair joint. [Figure 3] Fig. 3a is a partial cross-sectional side view showing a state where a valley filling material, which is one step of the corrugated pipe repairing method of the present invention, is attached, Fig. 3b is a partial cross-sectional side view showing a state where a seal portion is formed, which is one step of the corrugated pipe repairing method of the present invention, and Fig. 3c is a partial side view showing another embodiment of a state where a seal portion is formed. [Figure 4] Fig. 4a is a side cross-sectional view showing a part of a second embodiment of the pipe structure of the present invention, Fig. 4b is a side cross-sectional view showing a part of a third embodiment of the pipe structure of the present invention, Fig. 4c is a side cross-sectional view showing a part of a fourth embodiment of the pipe structure of the present invention, and Fig. 4d is a partial cross-sectional side view showing a part of a fifth embodiment of the pipe structure of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0015] Next, embodiments of the present invention will be described. [Pipe Structure 1] The pipe structure 1 shown in Figs. 1a and 1b includes a corrugated pipe 10 made of synthetic resin and a repair joint 20, wherein the corrugated pipe 10 has a repaired portion R between a first large-diameter portion 11A and a second large-diameter portion 11B. That is, in the corrugated pipe 10, the first large-diameter portion 11A and the second large-diameter portion 11B are continuous at least partially, and the repaired portion R is not cut. The repair joint 20 is attached to the corrugated pipe 10 so as to cover the space between the first large-diameter portion 11A and the second large-diameter portion 11B. The pipe structure 1 further includes: a first valley-filling material 30A provided on the outer circumference of a small-diameter portion 12A on the repaired portion side adjacent to the first large-diameter portion 11A (on the right side of the first large-diameter portion 11A in Fig. 1a); a second valley-filling material 30B provided on the outer circumference of a small-diameter portion 12B on the repaired portion side adjacent to the second large-diameter portion 11B (on the left side of the second large-diameter portion 11B in Fig. 1a); a first seal portion 40A provided on the outer circumferences of the first large-diameter portion 11A and the first valley-filling material 30A; and a second seal portion 40B provided on the outer circumferences of the second large-diameter portion 11B and the second valley-filling material 30B. The inner surfaces of split bodies 21a and 21b of the repair joint 20 respectively press the first seal portion 40A and the second seal portion 40B radially inward.

[0016] [Corrugated pipe 10] The corrugated pipe 10 is made of synthetic resin, in which large-diameter portions 11 each having a square cross-section and small-diameter portions 12 each having a circular cross-section are alternately provided. The repaired portion R provided between the first large-diameter portion 11A and the second large-diameter portion 11B of the corrugated pipe 10 is a site damaged by excavation work or the like that requires repair, or an opening for branching an internal cable as described later. The repaired portion R includes not only the case where the damaged portion is left as it is, but also the case where pretreatment is performed on the damaged portion, for example, the damaged portion is removed to form an opening for facilitating assembly of the repair joint 20. There are three large-diameter portions 11 between the first large-diameter portion 11A and the second large-diameter portion 11B of the corrugated pipe 10. However, the first large-diameter portion 11A and the second large-diameter portion 11B may be adjacent to each other, or one or more large-diameter portions may be provided therebetween. Nevertheless, if the distance between the first large-diameter portion 11A and the second large-diameter portion 11B is too long, the work becomes complicated. Therefore, it is preferable that 0 to 10 large-diameter portions, particularly 2 to 7 large-diameter portions, are provided between the first large-diameter portion 11A and the second large-diameter portion 11B. The material for the corrugated tube 10 can be a synthetic resin such as polyolefin or polyester, with high-density polyethylene being particularly preferred.

[0017] [Repair joint 20] As shown in Figures 2a and 2b, the repair joint 20 has a rectangular cross-section and is composed of a pair of radially divided sections 21a and 21b. Each section 21a and 21b has a U-shaped cross-section, resembling a gutter with openings at the top and front and back. As shown in Figures 2c and 2d, support pieces 25 are provided on the outer circumference of both sides 22 of each section 21a and 21b, projecting slightly below the dividing surface 23 and above the dividing surface 23. The support pieces 25 are provided on one of the sides 22. Here, they are provided along the entire length of the side 22, but they may be provided only on a portion of it. Therefore, when the pair of sections 21a and 21b are combined, the support pieces 25 support the other side of the opposite section. The position, length, height, etc., of the support pieces 25 are not particularly limited, as long as they are provided on the outside of the side 22 and prevent the other section from shifting in the left-right direction. The material of the repair joint 20 can be any material having the required strength, such as synthetic resin or metal. However, vinyl chloride is preferred because it is less prone to deterioration over the long term and has excellent durability. When using vinyl chloride, in order to ensure strength, the thickness of the divided parts 21a and 21b should preferably be 3 mm or more and 8 mm or less, and in particular 4 mm or more and 6 mm or less.

[0018] [Valley fill material 30] The valley filler material 30 (first valley filler material 30A and second valley filler material 30B) is provided in an annular shape around the outer circumference of the small diameter section 12, and as shown in Figure 2e, it consists of a ring-shaped elastic body with notches. Specifically, a central hole 31 with substantially the same diameter as the outer diameter of the small diameter section 12 is formed, and the shape of the outer surface 32 is substantially the same as the outer shape of the large diameter section 11. A cutting line (notch) 33 is formed from the outer surface 32 toward the central hole 31. The thickness of the valley filler material 30 is substantially the same as the length of the small diameter section 12 of the corrugated pipe 10. By making it a ring-shaped elastic body with notches, it can be easily attached to the small diameter section 12 on site. Furthermore, as will be described later, when the repair joint 20 is attached, it provides a reaction force to the repair joint 20, thus contributing to the sealing performance between the corrugated pipe 10 and the repair joint 20. The material of the valley filler 30 is not particularly limited as long as it is elastic, and examples include foamed resin and rubber. Because the valley filler 30 is elastic, it can be used even if its dimensions differ slightly from the large-diameter section of the corrugated pipe 10 to be repaired, especially if it is significantly larger. In other words, it has a high tolerance for dimensional differences. Therefore, it does not need to be prepared as a dedicated product for a specific corrugated pipe, but can be used as a general-purpose product for other similar pipes.

[0019] [Seal part 40] The sealing portion 40 (first sealing portion 40A and second sealing portion 40B) is annular in shape that seals the space between the corrugated pipe 10 and the repair joint 20, as shown in Figure 1a. However, even if it does not itself have a ring shape, for example, a sheet-like material may be wrapped around the large-diameter portion 11 and / or the valley-filling material 30 to form a ring shape. The material of the sealing portion 40 is not particularly limited as long as it is elastic. However, a material made by winding a water-swellable nonwoven fabric is preferred. By providing the sealing portion 40 on top of the valley filler material 30 in this manner, even if the water-absorbing, expandable nonwoven fabric of the sealing material over-expands, the valley filler material 30 can absorb the over-expanding of the water-absorbing, expandable nonwoven fabric, thereby suppressing water leakage and pipe damage after joint connection.

[0020] In this pipe structure 1, as shown in the enlarged view of Figure 1c, a waterproof tape 45 (for example, aluminum butyl tape) is provided between the outer circumference of the first valley filler 30A and the adjacent first large-diameter section 11A and the first seal section 40A in order to improve sealing performance. The waterproof tape 45 may also be provided on the outer circumference of other large-diameter sections 11 adjacent to the first valley filler 30A, as shown in Figure 1c. This waterproof tape 45 prevents water from entering the first valley filler 30A side between the corrugated pipe 10 and the repair joint 20. The waterproof tape 45 can also prevent water from entering from the cut line (cut) 33 of the valley filler 30. However, if sufficient sealing performance can be ensured by the valley filler 30 and the seal section 40, the waterproof tape 45 may not be necessary.

[0021] [Repair method for corrugated pipes] Next, a method for repairing a corrugated tube 10 having a repair area R will be described. Specifically, this is a method for repairing a corrugated tube 10 made of synthetic resin, in which large-diameter sections 11 and small-diameter sections 12 are alternately provided in the longitudinal direction, and the corrugated tube 10 having a repair area R between the first large-diameter section 11A and the second large-diameter section 11B is repaired without cutting the tube. This repair method comprises a first step of providing a first valley filler 30A on the outer circumference of a small diameter section 12A adjacent to a first large diameter section 11A; a second step of providing a second valley filler 30B on the outer circumference of a small diameter section 12B adjacent to a second large diameter section 11B; a third step of providing a first seal section 40A on the outer circumference of the first large diameter section 11A and the first valley filler 30A; a fourth step of providing a second seal section 40B on the outer circumference of the second large diameter section 11B and the second valley filler 30B; and a fifth step of covering the first seal section 40A and the second seal section 40B with a repair joint 20. Before proceeding with the repair method for the corrugated pipe 10, the damaged area may be pre-treated to adjust the repair area R, for example, by tidying up the open end of the damaged area or removing any protruding pieces that extend radially inward or outward from the damaged area.

[0022] Next, we will describe each step in detail. The first and second steps are steps to secure the support area of ​​the seal between the corrugated pipe 10 and the repair joint 20, respectively. As shown in Figure 3a, the first valley filler 30A is provided on the outer circumference of the first large-diameter section 11A and the small-diameter section 12A adjacent to the repair site, and the second valley filler 30B is provided on the outer circumference of the second large-diameter section 11B and the small-diameter section 12B adjacent to the repair site, thereby making the outer shape of each small-diameter section 12A (12B) substantially the same as that of the large-diameter section 11A (11B). Furthermore, as shown by reference numeral 30a in Figure 3a, valley filler material may be provided on the outer circumference of the second large-diameter section 11B and the small-diameter section 12 adjacent to the side opposite to the area to be repaired. It is preferable to provide the valley filler material on the side of each large-diameter section to be repaired, as this reduces the repair area (repair joint 20), but the position of the valley filler material can be appropriately selected by the on-site workers depending on the location and size of the damaged area.

[0023] The third and fourth steps are steps for forming seal portions 40A (40B) between the corrugated pipe 10 and the repair joint 20, respectively. Specifically, as shown in Figure 3b, seal portions 40A and 40B are provided on the outer circumference of the first large diameter portion 11A and the first valley filler 30A of the corrugated pipe 10, and on the outer circumference of the second large diameter portion 11B and the second valley filler 30B, respectively, so as to straddle the space between the large diameter portion and the valley filler. Alternatively, as shown in Figure 1c, waterproof tape 45 may be provided on the outer circumference of the large diameter portions on both sides adjacent to the valley filler 30 before forming the seal portions, and then the seal portions may be provided on the outer circumference of the waterproof tape 45. Furthermore, as shown in Figure 3c, the first sealing portion 40A may be provided on the outer circumference of the large-diameter portion 11A1 on the side of the repair area that is closer to the first valley filler material 30A. In this case, the first sealing portion 40A will be provided across the first large-diameter portion 11A, the first valley filler material, and the large-diameter portion 11A1, thus providing an even larger sealing area.

[0024] The fifth step involves assembling the divided parts 21a and 21b from the top and bottom of the corrugated pipe 10 so as to cover the first seal portion 40A and the second seal portion 40B, respectively, and then attaching the repair joint 20 to the outer circumference of the corrugated pipe 10. During the attachment of the repair joint 20, the inner surfaces of each divided part press the first seal portion 40A and the second seal portion 40B radially inward. The method of connecting the divided sections 21a and 21b is not particularly limited, but one method involves applying adhesive or the like to the inner surfaces of the divided surfaces 23 and support pieces 25 of the divided sections 21a and 21b, and then securing the connected divided section 21a to its outer circumference with cable ties. By connecting the two divided sections independently of the corrugated pipe 10 in this way, stable fixing is possible even if the corrugated pipe 10 and the repair joint 20 are made of different materials.

[0025] In this way, the repair area R of the corrugated pipe 10 can be covered with the repair joint 20, preventing water and other substances from entering the interior of the corrugated pipe 10 from the repair area R. Furthermore, since the corrugated pipe 10 can be repaired without cutting it, even if an external force is applied to the repaired pipe structure 1 so that the repaired area bends, it is supported by the continuous corrugated pipe 10 inside the repair joint 20, and bending can be prevented at the seal between the repair joint 20 and the corrugated pipe 10.

[0026] In the embodiments described above, a corrugated tube is shown in which large-diameter sections 11 with a square cross-section and small-diameter sections 12 with a circular cross-section are alternately arranged. However, the corrugated tube is not particularly limited as long as the large-diameter sections and small-diameter sections are alternately arranged in the longitudinal direction. For example, the cross-sectional shape of the large-diameter section may be polygonal or circular, and is not particularly limited. A single corrugated tube may also have large-diameter sections of different shapes. Similarly, the cross-sectional shape of the small-diameter section is not particularly limited as long as its circumscribed circle is smaller than the inscribed circle of the large-diameter section 11, and a single corrugated tube may have small-diameter sections of different shapes. Adjacent large-diameter sections 11 and small-diameter sections 12 may be annularly independent or spirally continuous. In the above-described embodiment, a repair joint with a square cross-section is given, but the cross-sectional shape is not particularly limited as long as it can cover the corrugated pipe. However, it is preferable to make the cross-sectional shape substantially the same as the outer shape of the large-diameter section of the corrugated pipe, as this makes the repair joint less likely to get in the way of the pipe structure after repair. Also, by making the cross-section square, it is easier to place the repaired area on the ground after repair, and it is preferable to make it a general-purpose product that can be easily matched to the shape of the large-diameter section of other similar pipes. In this case, the shape of the sealing portion will be formed to match the shape of the inner surface of the repair joint. In the above-described embodiment, a valley-filling material consisting of a ring-shaped elastic body with notches is given, but for example, a strip-shaped material may be wrapped around the outer circumference of the small-diameter portion 12 to form an outer shape that is substantially the same as that of the large-diameter portion 11. In the above embodiment, the support piece 25 of the divided body 21a is provided on one side surface 22, but as shown in Figure 2f, it may also be provided so as not to face the front half of one side surface 22 and the rear half of the other side surface 22. In this case, when the pair of divided bodies 21a and 21b are combined, the support piece 25 supports the side surface of the other divided body, further preventing it from shifting in the left-right direction.

[0027] "Second Embodiment" The pipe structure 2 in Figure 4a has a branching pipe 51 on one side of the divided parts that make up the repair joint 50. Other corrugated pipes 10, etc., are connected to this branching pipe 51. The branching pipe 51 extends perpendicular to the axis of the corrugated pipe 10, but its angle is not particularly limited. Unlike the pipe structure 1 in Figure 1, the repair location R of pipe structure 2 is an opening for branching the internal cables. This pipe structure 2 can also be assembled using the same corrugated pipe repair method as pipe structure 1.

[0028] "Third Embodiment" The pipe structure 3 in Figure 4b is obtained by cutting the corrugated pipe 10 and removing the repair area R. The other components are substantially the same as the pipe structure 1 in Figure 1. Even if the distance between the first large diameter section 11A and the second large diameter section 11B is shifted due to the cutting of the corrugated pipe 10 in this way, the sealing area remains unchanged. Therefore, work can be carried out on-site without worrying about the distance between the first large diameter section 11A and the second large diameter section 11B. This pipe structure 3 can be assembled using the same corrugated pipe repair method as pipe structure 1, after removing the repair area R of the corrugated pipe 10.

[0029] "Fourth Embodiment" In the pipe structure 4 shown in Figure 4c, an elastic member 60 (for example, a rubber sheet) is provided on the outer circumference of the large-diameter section 11 between the first large-diameter section 11A and the second large-diameter section 11B to fill the gap with the repair joint 20. The other configurations are substantially the same as those of the pipe structure 1 shown in Figure 1. By providing the elastic member 60 in this way, the strength of the repair joint 20 after repair can be improved. It is preferable to provide the elastic member 60 on all large-diameter sections between the first large-diameter section 11A and the second large-diameter section 11B, as in this embodiment, to maximize the strength, but the strength can be improved by providing it on the outer circumference of at least one large-diameter section. The elastic member 60 may also be provided one on each of the four outer circumferential surfaces of each large-diameter section, or it may be provided in an annular shape to cover the outer circumferential surfaces of the large-diameter sections. This pipe structure 4 can be assembled by performing a step of providing an elastic member 60 on the outer circumference of the large diameter section between the first large diameter section 11A and the second large diameter section 11B, before or after any of the steps of the corrugated pipe repair method used for pipe structure 1.

[0030] "Fifth Embodiment" In the pipe structure 5 of Figure 4d, the valley filler material 35 provided in the small diameter section 12 is composed of two members 36 and 37, each half the length. Except for being half the length, members 36 and 37 are substantially the same as the valley filler material 30 in Figure 1, and have a central hole with substantially the same diameter as the outer diameter of the small diameter section 12. The shape of the outer surface is substantially the same as the outer shape of the large diameter section, and a cutting line 33 is provided. In the pipe structure 5, members 36 and 37 are provided with their cutting lines 33 rotated 180 degrees around the axis of the pipe. In other words, the cutting lines 33 of member 36 and member 37 are not aligned in a straight line. This prevents water and other substances from entering through the cutting lines 33. In this embodiment, members 36 and 37 are rotated 180 degrees, but the installation angle is not particularly limited as long as the cutting lines 33 are not in a straight line. The cutting lines may also be set to be offset. Furthermore, the combined length of members 36 and 37 should be equal to the length of the small diameter section, and does not have to be half each. The valley filler may also be formed by arranging three or more members. [Explanation of Symbols]

[0031] 1, 2, 3, 4, 5 tube structure 10 corrugated tube 11 Large diameter section 11A First large diameter section 11B Second large diameter section 12 Small diameter section 12A 1st small diameter section 12B 2nd small diameter section 20 Repair joints 21a, 21b split body 22 Side view 23 Split plane 25 Support piece 30 Valley fill material 30A First Valley Filling Material 30B 2nd valley filling material 31 center hole 32 Outer surface 33 Cutting line 35 Valley fill material 36 Components for valley filling 37 Components for valley filling 40 Seal part 40A First seal section 40B Second seal section 45 Waterproof Tape 50 Repair joints 51 Branch pipe 60 Elastic members R Repaired area

Claims

1. A method for repairing a corrugated tube made of synthetic resin, wherein a large diameter portion with a square cross-section and a small diameter portion with a circular cross-section are independently and alternately arranged in an annular shape in the longitudinal direction, the repair area is located between the first large diameter portion and the second large diameter portion, and the first large diameter portion and the second large diameter portion are continuous in at least a portion thereof, A step of providing an elastic first valley filler in an annular shape on the outer circumference of the small diameter portion adjacent to the first large diameter portion, such that it has substantially the same shape as the outer shape of the large diameter portion. A step of providing an annular, elastic second valley filler on the outer circumference of the small diameter portion adjacent to the second large diameter portion, such that it has substantially the same shape as the outer shape of the large diameter portion. The process involves providing a first sealing portion in an annular shape on the outer circumference of the first large-diameter portion and the outer circumference of the first valley-filling material, The process involves providing a second sealing portion in an annular shape on the outer circumference of the second large-diameter portion and the outer circumference of the second valley filler, The process involves covering the repair area with a cylindrical repair joint composed of a pair of divided bodies that are divided radially into two, the first sealing portion, the second sealing portion, and the area to be repaired between them. The cross-section of the repair joint is substantially the same rectangle as the outer shape of the large-diameter portion. The repair joint has a support piece that protrudes above the dividing surface from the outside of the side surface of the divided body, preventing the other divided body from shifting in the left-right direction. The support pieces are provided on both sides of the repair joint. Repair method for corrugated tubes.

2. A branching cylinder is provided in at least one of the divided parts of the repair joint. A method for repairing a corrugated tube according to claim 1.

3. The process includes providing a waterproof tape between the outer circumference of the first valley filler and the first large diameter portion and the first seal portion, and / or between the outer circumference of the second valley filler and the second large diameter portion and the second seal portion. A method for repairing a corrugated tube according to claim 1 or 2.

4. A repair joint set for repairing a corrugated pipe made of synthetic resin, wherein a large diameter section with a square cross-section and a small diameter section with a circular cross-section are independently and alternately arranged in an annular shape in the longitudinal direction, the repair site is located between the first large diameter section and the second large diameter section, and the first large diameter section and the second large diameter section are continuous in at least a portion thereof, Two elastic valley-filling materials are provided in an annular shape on the outer circumference of the small-diameter portion so as to be substantially the same shape as the outer shape of the large-diameter portion, A cylindrical repair joint consisting of a pair of radially divided sections that cover the space between the first large-diameter section and the second large-diameter section, The corrugated pipe and the repair joint are provided with an annular sealing portion, The valley filler is annular in shape, having a central hole with substantially the same diameter as the outer diameter of the small-diameter portion, and a cutting line is formed from the outer surface toward the central hole. The cross-section of the repair joint is substantially the same rectangle as the outer shape of the large-diameter portion. The repair joint has a support piece that protrudes above the dividing surface from the outside of the side surface of the divided body, preventing the other divided body from shifting in the left-right direction. The support pieces are provided on both sides of the repair joint. Repair fitting set.

5. A branching cylinder is provided in at least one of the divided parts of the repair joint. The repair joint set according to claim 4.

6. A corrugated resin pipe having a large diameter section with a square cross-section and a small diameter section with a circular cross-section arranged alternately in an annular shape in the longitudinal direction, and a cylindrical repair joint composed of a pair of divided bodies that are divided into two in the radial direction, wherein the repaired portion provided between the first large diameter section and the second large diameter section, which are continuous in at least a part of the corrugated pipe, is repaired with the repair joint, An elastic first valley filler is provided in an annular shape on the outer circumference of the small diameter portion adjacent to the first large diameter portion, such that it has substantially the same shape as the outer shape of the large diameter portion. An elastic second valley filler is provided in an annular shape on the outer circumference of the small diameter portion adjacent to the second large diameter portion, such that it has substantially the same shape as the outer shape of the large diameter portion. The first sealing portion is provided in an annular shape on the outer circumference of the first large diameter portion and on the outer circumference of the first valley filler, It has a second sealing portion provided in an annular shape on the outer circumference of the second large diameter portion and on the outer circumference of the second valley filler, The repair joint is provided so as to cover the first seal portion, the second seal portion and the area to be repaired between them. The cross-section of the repair joint is substantially the same rectangle as the outer shape of the large-diameter portion. The repair joint has a support piece that protrudes above the dividing surface from the outside of the side surface of the divided body, preventing the other divided body from shifting in the left-right direction. The support pieces are provided on both sides of the repair joint. tube structure.

7. A branching cylinder is provided in at least one of the divided parts of the repair joint. The pipe structure according to claim 6.

8. A waterproof tape is provided between the outer circumference of the first valley filler and the first large diameter portion and the first seal portion, and / or between the outer circumference of the second valley filler and the second large diameter portion and the second seal portion. The pipe structure according to claim 6 or 7.

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