Method of branching rehabilitation pipes

Abstract

This provides a method for branching rehabilitation pipes that can be used in a wider variety of work sites than conventional methods. [Solution] The branching method according to the present invention is characterized by performing the following steps: (1) a rubber ring protrusion step S3 in which a branching unit is inserted from the branch pipe so that the lower end of the rubber ring protrudes into the rehabilitation pipe; (2) a push-in jig attachment step S4 in which a push-in jig capable of acting on the upper end of the sleeve is attached to the flange of the branch pipe; (3) a sleeve protrusion step S5 in which the push-in jig is activated so that the lower end of the sleeve protrudes from the lower end of the rubber ring into the rehabilitation pipe; (4) an expansion jig attachment step S6 in which a part of the push-in jig attached to the flange is replaced with an expansion jig capable of acting on the lower end of the sleeve; and (5) a sleeve expansion step S7 in which the expansion jig is activated so that the part of the sleeve protruding into the rehabilitation pipe is folded radially outward so as to wrap around the part of the rubber ring protruding into the rehabilitation pipe.

Description

Technical Field

[0001] The present invention relates to a method of branching a rehabilitation pipe provided in a main pipe to the branch pipe side in a branch pipe where the main pipe and the branch pipe intersect at a right angle.

Background Art

[0002] Conventionally, in order to repair pipes (for example, water pipes for supplying tap water to each household) deteriorated due to long-term use, rehabilitation pipes have been used. A rehabilitation pipe refers to a pipe obtained by attaching a flexible pipe coated with a resin having curability on its outer peripheral surface to the inner peripheral surface of the pipe to be repaired and curing it. According to this repair method, the time and cost required for repair can be significantly reduced compared to the case of replacing the pipe itself with a new one.

[0003] By the way, there is a branch portion in the pipe where the main pipe and the branch pipe intersect at a right angle. When repairing this branch portion of the pipe with a rehabilitation pipe, the flow path from the main pipe to the branch pipe is blocked by the rehabilitation pipe.

[0004] As a method for solving the problem in this branch portion, for example, there is a method of using a branch unit including a cylindrical metal sleeve and a cylindrical rubber ring attached to the outer periphery of the lower end of the sleeve (see Patent Document 1). This method includes: (1) a step of forming a perforation in the rehabilitation pipe with a perforation jig inserted from the branch pipe; (2) a step of assembling a branch unit including a cylindrical metal sleeve and a cylindrical rubber ring attached to the outer periphery of the lower end of the sleeve; (3) a step of inserting the branch unit from the branch pipe so that the lower end of the rubber ring protrudes into the rehabilitation pipe from the perforation; (4) a step of attaching a diameter-expanding jig that can act on both the upper and lower ends of the sleeve to the flange of the branch pipe; and (5) a step of operating the diameter-expanding jig so that after the lower end of the sleeve protrudes into the rehabilitation pipe from the lower end of the rubber ring, the protruding portion of the sleeve in the rehabilitation pipe is bent radially outward so as to entangle the protruding portion of the rubber ring in the rehabilitation pipe, and the sleeve is caulked to the rehabilitation pipe.

[0005] This method allows the rehabilitation pipe to be branched while maintaining a high level of watertightness. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6341726 [Overview of the project] [Problems that the invention aims to solve]

[0007] The diameter-expanding jig used in the conventional method described in Patent Document 1 has two functions: (A) the function of causing the lower end of the sleeve to protrude into the rehabilitation pipe from the lower end of the rubber ring, and (B) the function of bending the portion of the sleeve that protrudes into the rehabilitation pipe radially outward so as to wrap around the portion of the rubber ring that protrudes into the rehabilitation pipe, thereby causing the sleeve to be crimped to the rehabilitation pipe. As a result, it was large, as can be seen in Figure 7 of Patent Document 1. For this reason, the conventional method could not be used in sites where there was insufficient space above the branch pipe flange (for example, in sites where another pipe was located directly above the branch pipe flange).

[0008] This invention has been made in view of these circumstances, and aims to provide a method for branching a rehabilitation pipe that can be used in a wider variety of situations than conventional methods. [Means for solving the problem]

[0009] To solve the above problems, the present invention provides a method for branching a rehabilitation pipe, which is a method for branching a rehabilitation pipe provided in a main pipe to the branch pipe side in a branch pipe where a main pipe and a branch pipe intersect at a right angle, and comprises: (1) a rehabilitation pipe perforation step of forming a perforation in the rehabilitation pipe with a perforation jig inserted from the branch pipe; (2) a branch unit assembly step of assembling a branch unit comprising a cylindrical metal sleeve and a cylindrical rubber ring attached to the outer circumference of the lower end of the sleeve; (3) a rubber ring protrusion step of inserting the branch unit from the branch pipe so that the lower end of the rubber ring protrudes into the rehabilitation pipe from the perforation; and (4) a method that can act on the flange of the branch pipe with respect to the upper end of the sleeve. The method is characterized by performing the following steps: (5) a push-in jig attachment step of attaching a push-in jig; (6) a sleeve protrusion step of operating the push-in jig so that the lower end of the sleeve protrudes into the rehabilitation pipe from the lower end of the rubber ring; (7) a diameter-expanding jig attachment step of replacing a part of the push-in jig attached to the flange with a diameter-expanding jig that can act on the lower end of the sleeve; and (8) a sleeve diameter-expanding step of operating the diameter-expanding jig so that the part of the sleeve protruding into the rehabilitation pipe is folded radially outward so as to wrap around the part of the rubber ring protruding into the rehabilitation pipe, thereby forming a fixed wall between the rehabilitation pipe and the sleeve crimped to the rehabilitation pipe.

[0010] The branching unit may further include a movable wall that is screwed onto the outer surface of the sleeve between the mounting position of the rubber ring and the upper end of the sleeve. In this case, it is preferable that the branching method further includes, after the sleeve diameter expansion step, (8) a rubber ring compression jig installation step in which the remaining part of the push jig attached to the flange and the diameter expansion jig are replaced with a rubber ring compression jig that acts on the movable wall, and (9) a rubber ring compression step in which the movable wall is moved toward the fixed wall by operating the rubber ring compression jig, and the rubber ring is compressed between the movable wall and the fixed wall. [Effects of the Invention]

[0011] According to the present invention, a method for branching rehabilitation pipes that can be used in a wider variety of situations than conventional methods can be provided. [Brief explanation of the drawing]

[0012] [Figure 1] It is a diagram showing a branch pipe to which the branching method according to the present invention is applied. [Figure 2] It is a flowchart of the branching method according to the present invention. [Figure 3] It is a diagram related to the regenerative pipe piercing process. [Figure 4] It is a diagram showing a sleeve constituting a branch unit. [Figure 5] It is a diagram showing a rubber ring constituting a branch unit. [Figure 6] It is a diagram showing a nut constituting a branch unit. [Figure 7] It is a diagram showing a washer constituting a branch unit. [Figure 8] It is a diagram showing a branch unit. [Figure 9] It is a diagram related to the rubber ring protruding process. [Figure 10] It is a diagram showing a base flange unit constituting a pressing jig. [Figure 11] It is a diagram showing a sleeve cover constituting a pressing jig. [Figure 12] It is a diagram showing an intermediate plate constituting a pressing jig. [Figure 13] It is a diagram showing a pressurizer constituting a pressing jig. [Figure 14] It is a diagram related to the pressing jig mounting process. [Figure 15] It is a diagram related to the sleeve protruding process. [Figure 16] It is a diagram showing an expanding jig. [Figure 17] It is a diagram showing the operation of the expanding jig. [Figure 18] It is a diagram related to the expanding jig mounting process. [Figure 19] It is a diagram related to the expanding process. [Figure 20] It is a diagram showing a rubber ring compression jig. [Figure 21] It is a diagram related to the rubber ring compression jig mounting process. [Figure 22] It is a diagram related to the rubber ring compression process. [Modes for carrying out the invention]

[0013] Hereinafter, an embodiment of the branching method for a rehabilitation pipe according to the present invention will be described with reference to the attached drawings.

[0014] Figure 1 shows a repaired branch pipe 10 to which the branching method according to the present invention is applied. Figure (A) is a front view of the branch pipe 10, (B) is a top view, and (C) is a longitudinal cross-sectional view along the line X1-X1 in (B). As can be seen from these figures, the branch pipe 10 comprises a main pipe 11, a branch pipe 12, and a branch pipe flange 13 provided at the end of the branch pipe 12. The branch pipe 12 has a smaller diameter than the main pipe 11 and intersects the main pipe 11 at a right angle. The branch pipe flange 13 has four through holes 14a, 14b, 14c, and 14d.

[0015] A rehabilitation pipe 15 is attached to the inner surface of the main pipe 11. Essentially, there is no gap between the inner surface of the main pipe 11 and the outer surface of the rehabilitation pipe 15.

[0016] As can be seen from Figure 1(C), when a deteriorated main pipe 11 is repaired with a rehabilitated pipe 15, the flow path from the main pipe 11 to the branch pipe 12 is blocked by the rehabilitated pipe 15. The branching method according to the present invention aims to reconstruct the flow path from the main pipe 11 to the branch pipe 12 by branching the rehabilitated pipe 15 to the branch pipe 12 side while maintaining high watertightness. Note that "watertightness" refers to the ability to prevent the fluid flowing inside the main pipe 11 (for example, tap water) from coming into contact with the inner surface of the deteriorated main pipe 11.

[0017] Figure 2 shows a flowchart of the branching method according to the present invention. As can be seen from the figure, the branching method according to the present invention includes nine steps that are executed sequentially (rehabilitation pipe drilling step S1, branching unit assembly step S2, rubber ring protrusion step S3, push-in jig attachment step S4, sleeve protrusion step S5, diameter expansion jig attachment step S6, sleeve diameter expansion step S7, rubber ring compression jig attachment step S8, and rubber ring compression step S9). Note that the branching unit assembly step S2 may be performed before the rehabilitation pipe drilling step S1, or simultaneously with the rehabilitation pipe drilling step S1.

[0018] [Rehabilitation pipe drilling process S1] First, with reference to Figure 3, the rehabilitation pipe perforation process S1 of the branching method according to the present invention will be described. In this process S1, the drill bit 21 of the perforation jig 20 is inserted from the branch pipe 12, and while the drill bit 21 is pressed against the outer surface of the rehabilitation pipe 15, the shaft 22 extending upward from the drill bit 21 is rotated to form a circular perforation 16 in the rehabilitation pipe 15. The diameter of the perforation 16 is approximately equal to the outer diameter of the drill bit 21 and slightly smaller than the inner diameter of the branch pipe 12.

[0019] [Branch unit assembly process S2] Next, with reference to Figures 4 to 8, the branching unit assembly process S2 of the branching method according to the present invention will be described. In this process S2, the branching unit 70 is completed by assembling four components (sleeve 30, rubber ring 40, nut 50, and washer 60).

[0020] Figure 4 shows the sleeve 30 that constitutes the branching unit 70. Figure (A) is a front view of the sleeve 30, (B) is a right side view, (C) is a top view, (D) is a bottom view, and (E) is a longitudinal cross-sectional view along the line X2-X2 in (C). As can be seen from these figures, the sleeve 30 comprises a cylindrical portion 31 extending in the vertical direction, a male screw portion 32 provided on the outer circumferential surface near the lower end of the cylindrical portion 31, and two rectangular notches 33a and 33b formed at two opposing locations on the upper end of the cylindrical portion 31.

[0021] The sleeve 30 is entirely made of metal such as stainless steel.

[0022] Figure 5 shows the rubber ring 40 that constitutes the branching unit 70. Figure (A) is a front view of the rubber ring 40, (B) is a right side view, (C) is a top view, (D) is a bottom view, and (E) is a longitudinal cross-sectional view along the line X3-X3 in (C). As can be seen from these figures, the rubber ring 40 has an outer circumferential surface portion including a washer mounting portion 41a, a build-up portion 41b, and a protruding portion 41c, and an inner circumferential surface portion including an upper inner circumferential surface portion 42a, a tapered portion 42b, a lower inner circumferential surface portion 42c, and a ring portion 42d.

[0023] The washer mounting portion 41a is the area where the washer 60 is mounted. The outer diameter of the rubber ring 40 in the washer mounting portion 41a is approximately equal to the inner diameter of the washer 60 (the inner diameter in the rubber ring mounting portion 61b, which will be described later).

[0024] The built-up portion 41b is a part that restricts the movement of the washer 60. The outer diameter of the rubber ring 40 in the built-up portion 41b is larger than the inner diameter of the washer 60 (the inner diameter of the rubber ring mounting portion 61b, which will be described later).

[0025] The build-up portion 41b also serves to restrict the movement of the rubber ring 40 in the perforated portion 16. The outer diameter of the rubber ring 40 in the build-up portion 41b is larger than the diameter of the perforated portion 16. Therefore, the build-up portion 41b cannot pass through the perforated portion 16.

[0026] The protruding portion 41c is the part that will become the "fixed wall" described later. The outer diameter of the rubber ring 40 at the protruding portion 41c is slightly smaller than the diameter of the perforated portion 16. Therefore, the protruding portion 41c can pass through the perforated portion 16.

[0027] The upper inner circumferential surface portion 42a is the area into which the lower end of the sleeve 30 (cylindrical portion 31) is inserted. The inner diameter of the rubber ring 40 on the upper inner circumferential surface portion 42a is slightly smaller than the outer diameter of the cylindrical portion 31. Therefore, the rubber ring 40 attached to the cylindrical portion 31 will not fall off the cylindrical portion 31 due to a force of gravity.

[0028] The tapered portion 42b and the lower inner circumferential portion 42c are parts that restrict the sleeve 30 (cylindrical portion 31), which is inserted from the upper inner circumferential portion 42a side, from advancing further downward (inward). The inner diameter of the rubber ring 40 in the tapered portion 42b and the lower inner circumferential portion 42c is smaller than the outer diameter of the cylindrical portion 31.

[0029] The ring portion 42d is the part that will become the "fixed wall" described later, and is located at the lower end of the lower inner circumferential surface portion 42c (i.e., the lowest end of the rubber ring 40). The inner diameter of the rubber ring 40 is smallest at the ring portion 42d.

[0030] Here, the restriction by the tapered portion 42b and the lower inner circumferential portion 42c is not complete. If the cylindrical portion 31, which has been inserted up to the upper inner circumferential portion 42a, is pushed in with even greater force, the lower end of the cylindrical portion 31 moves downward (inward) while pushing the tapered portion 42b, the lower inner circumferential portion 42c, and the ring portion 42d radially outward, and finally protrudes from the lower end of the rubber ring 40.

[0031] Figure 6 shows the nut 50 that constitutes the branching unit 70. Figure (A) is a front view of the nut 50, (B) is a right side view, (C) is a top view, (D) is a bottom view, and (E) is a longitudinal cross-sectional view along the line X4-X4 in (C). As can be seen from these figures, the nut 50 comprises a low-profile cylindrical portion 51 extending in the vertical direction, a female threaded portion 52 provided over almost the entire inner circumference of the cylindrical portion 51, and rectangular notches 53a and 53b formed at two opposing locations on the upper end of the cylindrical portion 51.

[0032] The female threaded portion 52 of the nut 50 is configured to screw onto the male threaded portion 32 of the sleeve 30. When only the nut 50 is rotated with the threaded portions 32 and 52 screwed together, the nut 50 moves along the axial direction of the sleeve 30. In other words, the nut 50 is configured to move vertically along the sleeve 30. However, the nut 50 will not move due to external forces in the vertical direction (except for large external forces that would destroy the threaded portions 32 and 52).

[0033] The nut 50 is entirely made of a metal such as stainless steel. The nut 50 corresponds to the "movable wall" of the present invention.

[0034] Figure 7 shows the washer 60 that constitutes the branching unit 70. Figure (A) is a front view of the washer 60, (B) is a right side view, (C) is a top view, (D) is a bottom view, and (E) is a longitudinal cross-sectional view along the line X5-X5 in (C). As can be seen from these figures, the washer 60 has an inner circumferential surface portion that includes a sleeve insertion portion 61a and a rubber ring mounting portion 61b.

[0035] The rubber ring mounting portion 61b is the part where the rubber ring 40 (washer mounting portion 41a) is mounted. The inner diameter of the washer 60 in the rubber ring mounting portion 61b is approximately equal to the outer diameter of the rubber ring 40 in the washer mounting portion 41a. On the other hand, the inner diameter of the washer 60 in the sleeve insertion portion 61a is smaller than the inner diameter of the washer 60 in the rubber ring mounting portion 61b and is approximately equal to the outer diameter of the sleeve 30 (cylindrical portion 31).

[0036] The washer 60 is made entirely of a material that is mechanically weaker than the material that makes up the nut 50 (for example, plastic). This configuration is intended to prevent the nut 50 from deforming or breaking during the rubber ring compression process S9.

[0037] Figure 8 shows a branching unit 70 consisting of a sleeve 30, a rubber ring 40, a nut 50, and a washer 60. Figure (A) is a front view of the branching unit 70, and (B) is a longitudinal cross-sectional view.

[0038] In the branch unit assembly process S2, the branch unit 70 is assembled using the following procedure. Step 1: After inserting the sleeve 30 onto the nut 50, rotate the nut 50 to screw the female threaded portion 52 of the nut 50 onto the male threaded portion 32 of the sleeve 30. Step 2: Insert sleeve 30 onto washer 60. Step 3: Attach the rubber ring 40 to the lower end of the sleeve 30. Step 4: Place the washer 60 over the upper end of the rubber ring 40 (washer mounting portion 41a).

[0039] [Rubber ring protrusion process S3] Next, the rubber ring protrusion step S3 of the branching method according to the present invention will be explained with reference to Figure 9(A), which is a top view of the branch pipe 10 etc. after the rubber ring protrusion step S3 has been performed, and Figure 9(B), which is a longitudinal cross-sectional view along the line X6-X6 in (A). In this step S3, the branching unit 70 is inserted from the branch pipe 12, and the protruding portion 41c and ring portion 42d of the rubber ring 40 protrude from the perforated portion 16 (see Figure 3) into the rehabilitation pipe 15 by a predetermined amount P1.

[0040] In Figure 9, an additional build-up section adjacent to the build-up section 41b is formed by wrapping and bonding a rubber sheet around the outer surface of the protruding section 41c so that the amount of protrusion of the rubber ring 40 is a predetermined amount P1. The outer diameter of the rubber ring 40 in the additional build-up section is approximately equal to the outer diameter of the rubber ring 40 in the build-up section 41b. Therefore, the branching unit 70 stops lowering when the additional build-up section comes into contact with the outer surface of the rehabilitation pipe 15 (the outer edge of the perforated section 16).

[0041] If the protrusion amount P1 is achieved without forming an additional build-up section, then naturally, no additional build-up section is formed. In this case, the branching unit 70 stops lowering when the build-up section 41b contacts the outer surface of the rehabilitation pipe 15 (the outer edge of the perforated section 16).

[0042] [Pressing jig installation process S4] Next, the push-in jig attachment process S4 of the branching method according to the present invention will be described with reference to Figures 10 to 14. In this process S4, the push-in jig 120, which is composed of four components (base flange unit 80, sleeve cover 90, intermediate plate 100, and pressurizer 110), is attached to the branch pipe flange 13.

[0043] Figure 10 shows the base flange unit 80 that constitutes the push-in jig 120. Figure (A) is a front view of the base flange unit 80, (B) is a top view, and (C) is a longitudinal cross-sectional view along the line X7-X7 in (B). As can be seen from these figures, the base flange unit 80 comprises a base flange 81 whose outer diameter is approximately equal to the outer diameter of the branch pipe flange 13, two first rods 82a and 82b extending upward from the top surface of the base flange 81, and two second rods 83a and 83b penetrating the base flange 81 in the thickness direction (vertical direction).

[0044] The base flange 81 has an insertion opening 84 whose inner diameter is approximately equal to the inner diameter of the branch pipe 12, two bolt holes 85a and 85d located in positions corresponding to the through holes 14a and 14d of the branch pipe flange 13 (see Figure 1), and two drilled holes 85b and 85c located in positions corresponding to the through holes 14b and 14c of the branch pipe flange 13 (see Figure 1). The inner circumferential surfaces of the bolt holes 85a and 85d are provided with female threads.

[0045] Both the first rods 82a and 82b have a small-diameter section 86 with a smaller outer diameter than the rest of the rod, and a male threaded portion is provided on the outer circumferential surface of the small-diameter section 86. The small-diameter section 86 is located at the upper end of the first rods 82a and 82b.

[0046] Both the second rods 83a and 83b have male threads along their entire outer surface. The second rod 83a is screwed into the bolt hole 85a, and the second rod 83b is screwed into the bolt hole 85d.

[0047] Note that in drawings other than Figure 10(A), the male threaded portions provided on the first rods 82a, 82b and the second rods 83a, 83b are not shown.

[0048] Figure 11 shows the sleeve cover 90 that constitutes the push-in jig 120. Figure (A) is a front view of the sleeve cover 90, (B) is a top view, and (C) is a longitudinal cross-sectional view along the line X8-X8 in (B). As can be seen from these figures, the sleeve cover 90 comprises a cover flange 91 whose outer diameter is slightly smaller than the outer diameter of the branch pipe flange 13, and a cylindrical portion 92 extending downward from the center of the lower surface of the cover flange 91.

[0049] The cover flange 91 has an insertion opening 93 whose inner diameter is approximately equal to the inner diameter of the cylindrical portion 92 and the outer diameter of the sleeve 30 (cylindrical portion 31), four through holes 94a, 94b, 94c, 94d located in positions corresponding to the through holes 14a, 14b, 14c, 14d of the branch pipe flange 13 (see Figure 1), two through holes 95a, 95b located in positions corresponding to the first rods 82a, 82b (see Figure 10), and two opposing engaging projections 96a, 96b provided on the inner circumferential surface of the insertion opening 93. The engaging projections 96a, 96b are configured to engage with the notches 33a, 33b of the sleeve 30.

[0050] The cylindrical portion 92 has a scale portion 97 that is referenced in the sleeve protrusion process S5. As mentioned above, the inner diameter of the cylindrical portion 92 is approximately equal to the outer diameter of the sleeve 30 (cylindrical portion 31). Also, the outer diameter of the cylindrical portion 92 is approximately equal to the inner diameter of the branch pipe 12.

[0051] Figure 12 shows the intermediate plate 100 that constitutes the push-in jig 120. Figure (A) is a front view of the intermediate plate 100, (B) is a top view, and (C) is a longitudinal cross-sectional view along line X9-X9 in (B). As can be seen from these figures, the intermediate plate 100 is composed of a single oval-shaped member and has two through holes 101a and 101b located in positions corresponding to the first rods 82a and 82b (see Figure 10), and a mortar-shaped recess 102 provided in the center of the top surface.

[0052] Figure 13 shows the pressurizer 110 that constitutes the pressing jig 120. Figure (A) is a front view of the pressurizer 110, (B) is a top view, and (C) is a longitudinal cross-sectional view along the line X10-X10 in (B). As can be seen from these figures, the pressurizer 110 comprises a support plate 111 having the same outer shape as the intermediate plate 100 (see Figure 12), a guide portion 113 fitted into the center of the support plate 111, and a pressurizing rod 112 passing through the guide portion 113.

[0053] The support plate 111 has two through holes 114a and 114b located in positions corresponding to the first rods 82a and 82b (see Figure 10).

[0054] The guide portion 113 has a through hole extending in the vertical direction. A female threaded portion is provided on the inner circumferential surface of the through hole.

[0055] The pressure rod 112 has an upper end portion 112a which is hexagonal prism-shaped and easy to grip with a tool such as a wrench, an intermediate portion 112b which has a male threaded portion on its outer circumference, and a conical lower end portion 112c which has a conical shape corresponding to the mortar-shaped recess 102 of the intermediate plate 100. The intermediate portion 112b is configured to be screwed into the guide portion 113. Therefore, when the pressure rod 112 is rotated with a wrench or the like, the pressure rod 112 moves vertically relative to the guide portion 113 (support plate 111).

[0056] Figure 14 shows a branch pipe 10 and a push-in jig 120 attached to the branch pipe flange 13 of the branch pipe 10. Figure (A) is a top view of the branch pipe 10 and the push-in jig 120, and (B) is a longitudinal cross-sectional view along the line X11-X11 in (A).

[0057] In the push-in jig installation process S4, the push-in jig 120 is attached to the branch pipe flange 13 using the following procedure. Procedure 1: Place the base flange 81 of the base flange unit 80 onto the branch pipe flange 13. At this time, the two second rods 83a and 83b of the base flange unit 80 pass through the through holes 14a and 14d of the branch pipe flange 13. Step 2: Screw nuts onto the lower ends of the second rods 83a and 83b to secure the base flange 81 to the branch pipe flange 13. Step 3: Place the cylindrical portion 92 of the sleeve cover 90 over the cylindrical portion 31 of the sleeve 30 so that the engaging protrusions 96a and 96b of the sleeve cover 90 engage with the notches 33a and 33b of the sleeve 30. At this time, the four rods 82a, 82b, 83a, and 83b of the base flange unit 80 pass through the four through holes 95a, 95b, 94a, and 94d of the cover flange 91. Step 4: Place the intermediate plate 100 on the cover flange 91. At this time, the two first rods 82a and 82b of the base flange unit 80 pass through the through holes 101a and 101b of the intermediate plate 100. Step 5: Place the support plate 111 of the pressurizer 110 on the base flange unit 80 (the step created by the small diameter portion 86 of the first rods 82a, 82b and the other portion). At this time, the two first rods 82a, 82b of the base flange unit 80 pass through the through holes 114a, 114b of the support plate 111. Step 6: Screw nuts onto the upper ends (small diameter portions 86) of the first rods 82a and 82b, and fix the support plate 111 to the first rods 82a and 82b.

[0058] [Sleeve protrusion process S5] Next, the sleeve protrusion step S5 will be described with reference to Figure 15(A), which is a top view of the branch pipe 10 etc. after the sleeve protrusion step S5 of the branching method according to the present invention, and Figure 15(B), which is a longitudinal cross-sectional view along the line X12-X12 in (A). In this step S5, a large force is applied to the upper end of the sleeve 30 (cylindrical portion 31) via the intermediate plate 100 and the sleeve cover 90 (cover flange 91) by rotating the pressure rod 112 of the pressurizer 110 with a tool such as a wrench to move the pressure rod 112 downward. In other words, in this step S5, the sleeve 30 is pushed downward by operating the push-in jig 120, so that the lower end of the sleeve 30 protrudes from the lower end of the rubber ring 40 into the rehabilitation pipe 15 by a predetermined amount P2.

[0059] As mentioned above, the outer diameter of the rubber ring 40 in the build-up portion 41b (or additional build-up portion) is larger than the diameter of the perforated portion 16. Therefore, even when the sleeve 30 is pushed in, the position of the rubber ring 40 does not change.

[0060] In step S5, it is preferable to rotate the pressure rod 112 while referring to the scale 97 attached to the cylindrical portion 92 of the sleeve cover 90. This makes it easier to extend the sleeve 30 by a predetermined amount P2.

[0061] [Expanding jig mounting process S6] Next, with reference to Figures 16 to 18, the diameter expansion jig attachment process S6 of the branching method according to the present invention will be described. In this process S6, a part of the push-in jig 120 (intermediate plate 100 and pressurizer 110) attached to the branch pipe flange 13 is replaced with the diameter expansion jig 130. In other words, in this configuration S6, the other part of the push-in jig 120 (base flange unit 80 and sleeve cover 90) and the diameter expansion jig 130 are attached to the branch pipe flange 13.

[0062] Figure 16 shows the diameter-expanding jig 130. Figure (A) is a front view of the diameter-expanding jig 130, (B) is a top view, and (C) is a longitudinal cross-sectional view along the line X13-X13 in (B). As can be seen from these figures, the diameter-expanding jig 130 comprises a flange 131, a fixed base 132, a rotating base 133, a rotation restricting part 134, a shaft cover 135, a shaft 136, a nut 137, a tip 138, a diameter-expanding roller 139, a sliding body 140, and a knob 141.

[0063] The flange 131 has an oval-shaped through-hole 142b located in a position corresponding to the through-hole 14b of the branch pipe flange 13, the drilled hole 85b of the base flange 81, and the through-hole 94b of the cover flange 91, and an oval-shaped through-hole 142a located in a position corresponding to the through-hole 14c of the branch pipe flange 13, the drilled hole 85c of the base flange 81, and the through-hole 94c of the cover flange 91.

[0064] The fixed base 132 has a low profile cylindrical shape centered on a first axis Z1 that extends in the vertical direction. The fixed base 132 is fixed to the upper surface of the flange 131 in a way that prevents rotation. The first axis Z1 passes through the center of the flange 131.

[0065] The flange 131 and the fixed base 132 have a circular insertion opening 143 centered on the first axis Z1.

[0066] The rotating base 133 has a low profile cylindrical shape centered on the first rotation axis Z1. The rotating base 133 has a smaller outer diameter than the fixed base 132 and is provided on the upper surface of the fixed base 132 so as to allow rotation around the first axis Z1.

[0067] The rotation restricting section 134 is a hollow hexagonal prism-shaped member centered on a second axis Z2 (≠ first axis Z1) extending in the vertical direction, and is fixed to the upper surface of the rotation base 133 in a way that prevents rotation. The rotation restricting section 134 has two opposing surfaces, a first restricting groove 134a and a second restricting groove 134b, both extending in the vertical direction. The restricting grooves 134a and 134b restrict the rotation of the knob 141 around the second axis Z2. On the other hand, the restricting grooves 134a and 134b do not restrict the vertical movement of the knob 141.

[0068] The shaft cover 135 is a nearly cylindrical member centered on the first axis Z1. The shaft cover 135 is fixed non-rotatably to the lower center of the rotating base 133 and extends downward through the insertion opening 143.

[0069] The rotating base 133 and the shaft cover 135 have circular insertion openings 144 and 145 centered on the second axis Z2.

[0070] The shaft 136 is a long, rod-shaped member that extends vertically through the rotation restricting portion 134 and the insertion openings 144 and 145. The shaft 136 has a male threaded portion on its outer circumference near the upper end, which allows it to be screwed onto the nut 137. The shaft 136 is configured to allow the slide body 140 to move vertically along the shaft 136, while restricting the rotation of the slide body 140 around the shaft 136.

[0071] The slide body 140 is a cylindrical member having an outer diameter smaller than the inner diameter of the rotation restricting portion 134. The slide body 140 is supported by a coil spring located below it.

[0072] The knob portion 141 extends horizontally from the outer circumferential surface of the sliding body 140.

[0073] As mentioned above, the nut 137 is screwed onto the male threaded portion of the shaft 136. The outer diameter of the nut 137 is larger than the inner diameter of the slide body 140. Due to this size difference, the nut 137 prevents the shaft 136 and the tip portion 138 and the enlarged diameter roller 139 provided at its lower end from falling off due to their own weight. It can also be said that the nut 137 restricts the downward movement of the shaft 136.

[0074] The tip portion 138 is fixed to the lower end of the shaft 136 in a way that prevents rotation. The tip portion 138 has a circular lower surface. The diameter of the lower surface of the tip portion 138 is approximately equal to the outer diameter of the shaft cover 135 and slightly smaller than the inner diameter of the sleeve 30 (cylindrical portion 31).

[0075] The diameter-expanding roller 139 is rotatably mounted on the tip portion 138 by a rotation axis that is inclined at approximately 45° with respect to the vertical direction.

[0076] The diameter-expanding jig 130 can take on the states shown in Figures 17(A) to (D), as well as intermediate states between these states.

[0077] Figure 17(A) shows the state in which the knob portion 141 is positioned in the first regulating groove 134a of the rotation regulating portion 134, and the shaft 136 and tip portion 138 are pulled up to their maximum extent by the nut 137. This state is the same as the state shown in Figure 16.

[0078] When the nut 137 is loosened (rotated around the second axis Z2) in the state shown in Figure 17(A), the shaft 136 and tip 138 move downward to the state shown in Figure 17(B). Naturally, when the nut 137 is tightened, the shaft 136 and tip 138 that moved downward return to their original position (the position in Figure 17(A)).

[0079] In the state shown in Figure 17(B), if the shaft 136, nut 137, tip 138, slide body 140, and knob 141 are pulled straight up against gravity, and the knob 141, which is no longer restricted by the rotation restricting part 134, is rotated 180° around the second axis Z2, and then the parts that were pulled up are allowed to fall under their own weight, the state shown in Figure 17(C) is obtained. In this state, the knob 141 is located in the second restricting groove 134b of the rotation restricting part 134. When the knob 141, which is no longer restricted by the rotation restricting part 134, is rotated around the second axis Z2, the slide body 140, shaft 136, nut 137, and tip 138, which are directly or indirectly connected to the knob 141, also rotate by the same amount around the second axis Z2.

[0080] When the rotating base 133 is rotated 180° around the first axis Z1 relative to the fixed base 132 in the state shown in Figure 17(C), the state shown in Figure 17(D) is obtained. When the rotating base 133 is rotated around the first axis Z1, the rotation restricting part 134 and shaft cover 135 fixed to it also rotate by the same amount around the first axis Z1. Furthermore, when the rotating base 133 rotates around the first axis Z1, the sliding body 140, knob part 141, shaft 136, nut 137, and tip part 138 also rotate by the same amount around the first axis Z1.

[0081] Figure 18 shows the branch pipe 10, etc., after the diameter expansion jig mounting step S6 of the branching method according to the present invention has been performed. Figure (A) is a top view, and (B) is a longitudinal cross-sectional view along the line X14-X14 in (A). As described above, in this step S6, a part of the push jig 120 attached to the branch pipe flange 13 (intermediate plate 100 and pressurizer 110) is replaced with a diameter expansion jig 130.

[0082] More specifically, in this process S6, a portion of the pressing jig 120 is replaced with the diameter expanding jig 130 using the following procedure. Procedure 1: Screw nuts onto the second rods 83a and 83b from the upper end, and fix the cover flange 91 of the sleeve cover 90 to the branch pipe flange 13. In other words, ensure that the cover flange 91 does not lift up even when the pressurizer 110 is removed. Step 2: Remove the pressurizer 110. Step 3: Remove the intermediate plate 100. Step 4: The diameter-expanding jig 130 is installed by inserting the shaft cover 135, shaft 136, and tip 138 of the diameter-expanding jig 130, which are in the state shown in Figure 17(A), into the cylindrical portion 31 of the sleeve 30 through the insertion opening 93 of the sleeve cover 90. Step 5: Pass bolts through the through hole 14b of the branch pipe flange 13, the drilled hole 85b of the base flange unit 80, the through hole 94b of the sleeve cover 90, and the through hole 142b of the diameter-expanding jig 130, and screw nuts onto them. Similarly, pass bolts through the through hole 14c of the branch pipe flange 13, the drilled hole 85c of the base flange unit 80, the through hole 94c of the sleeve cover 90, and the through hole 142a of the diameter-expanding jig 130, and screw nuts onto them. This fixes the diameter-expanding jig 130 to the branch pipe flange 13.

[0083] [Sleeve diameter expansion process S7] Next, the sleeve diameter expansion step S7 of the branching method according to the present invention will be described with reference to Figures 17 and 19. In this step S7, the portion of the sleeve 30 (cylindrical portion 31) that protrudes into the rehabilitation pipe 15 is bent radially outward so as to wrap around the portions 41c and 42d of the rubber ring 40 that protrude into the rehabilitation pipe 15, so that the rehabilitation pipe 15 and the sleeve 30 that is crimped to the rehabilitation pipe 15 form a fixed wall.

[0084] More specifically, in step S7, after performing the operations shown in Figure 17(A)→(B)→(C), the shaft 136 and tip 138 are slowly pulled up by tightening the nut 137, while the operations shown in Figure 17(C)→(D)→(C)→(D)... are repeated. As a result, the diameter expanding jig 130 goes from the state shown in Figure 18 to the state shown in Figure 19(A), then through the state shown in (B), and finally to the state shown in (C). In addition, this operation causes the sleeve 30 (cylindrical part 31) to be crimped to the rehabilitation pipe 15.

[0085] [Rubber ring compression jig installation process S8] Next, with reference to Figure 20, the rubber ring compression jig attachment step S8 of the branching method according to the present invention will be described. In this step S8, the remaining parts of the push-in jig 120 (base flange unit 80 and sleeve cover 90) and the diameter expansion jig 130 attached to the branch pipe flange 13 are replaced with a rubber ring compression jig 150 that acts on the nut 50 of the branching unit 70.

[0086] Figure 20 shows the rubber ring compression jig 150. Figure (A) is a front view of the rubber ring compression jig 150, (B) is a right side view, (C) is a top view, (D) is a bottom view, and (E) is a longitudinal cross-sectional view along the line X15-X15 in (C). As can be seen from these figures, the rubber ring compression jig 150 comprises a cylindrical portion 151 extending in the vertical direction, a lid portion 152 that closes the opening at the upper end of the cylindrical portion 151, a gripping portion 153 provided in the center of the upper surface of the lid portion 152, an insertion opening 154 that penetrates the lid portion 152 and the gripping portion 153 in the vertical direction, a shaft 155 inserted into the insertion opening 154, and a rotation restricting portion 156 provided at the lower end of the shaft 155 inside the cylindrical portion 151.

[0087] The cylindrical portion 151 has two opposing engaging projections 157a and 157b at its lower end. The engaging projections 157a and 157b extend downward from the lower end of the cylindrical portion 151 so that they can engage with the notches 53a and 53b of the nuts 50 that constitute the branching unit 70.

[0088] The cylindrical portion 151 has an outer diameter slightly smaller than the inner diameter of the branch pipe 12 and an inner diameter approximately equal to the outer diameter of the sleeve 30 (cylindrical portion 31).

[0089] The gripping portion 153 is a hexagonal prism-shaped member that is easy to grip with a tool such as a wrench.

[0090] The shaft 155 is a rod-shaped member that extends vertically through the insertion opening 154. The shaft 155 has an outer diameter slightly smaller than the inner diameter of the insertion opening 154 and is movable and rotatable vertically relative to the lid 152 and the gripping portion 153. The shaft 155 has a hexagonal prism-shaped upper end that is easy to grip with a tool such as a wrench.

[0091] The rotation restricting portion 156 is a low-profile, nearly cylindrical member. The outer diameter of the rotation restricting portion 156 is smaller than the inner diameter of the cylindrical portion 151 and is approximately equal to the inner diameter of the sleeve 30 (cylindrical portion 31).

[0092] The rotation restricting portion 156 has two opposing engagement projections 158a and 158b on its outer circumferential surface. The engagement projections 158a and 158b extend from the outer circumferential surface of the rotation restricting portion 156 toward the inner circumferential surface of the cylindrical portion 151 so as not to contact the notches 33a and 33b of the sleeve 30 (cylindrical portion 31).

[0093] As mentioned above, in this step S8, the remaining parts of the push-in jig 120 (base flange unit 80 and sleeve cover 90) and the diameter-expanding jig 130 attached to the branch pipe flange 13 are replaced with a rubber ring compression jig 150 that acts on the nut 50 of the branch unit 70.

[0094] More specifically, in this step S8, the remaining portion of the pressing jig 120 and the diameter expanding jig 130 are replaced with the rubber ring compression jig 150 in the following procedure. Step 1: Remove the diameter expansion jig 130. Step 2: Remove sleeve cover 90. Step 3: Remove the base flange unit 80. Step 4: Place the rubber ring compression jig 150 over the sleeve 30 so that the engaging projections 157a and 157b of the cylindrical portion 151 engage with the notches 53a and 53b of the nut 50, and the engaging projections 158a and 158b of the rotation restricting portion 156 engage with the notches 33a and 33b of the sleeve 30 (cylindrical portion 31).

[0095] Figure 21 shows a cross-sectional view of the branch pipe 10, etc., after the rubber ring compression jig attachment step S8 of the branching method according to the present invention has been performed.

[0096] [Rubber ring compression process S9] Next, with reference to Figure 22, the rubber ring compression step S9 of the branching method according to the present invention will be described. In this step S9, the rubber ring compression jig 150 is operated to move the movable wall (nut 50) toward the fixed wall (the part in which the sleeve 30 is crimped to the rehabilitation pipe 15), and the built-up portion 41b of the rubber ring is compressed between the movable wall and the fixed wall. If an additional built-up portion exists, the additional built-up portion is also compressed along with the built-up portion 41b.

[0097] More specifically, in step S9, the shaft 155 of the rubber ring compression jig 150 is gripped with a wrench or the like to prevent the shaft 155 and the rotation restricting part 156 from rotating (i.e., the rotation of the cylindrical part 31 of the sleeve 30 is restricted), while the gripping part 153 is gripped with a wrench or the like to rotate the gripping part 153 and the cylindrical part 151. As a result, the nut 50 constituting the branching unit 70 rotates relative to the cylindrical part 31 and moves downward, compressing the built-up part 41b (and additional built-up part) of the rubber ring 40 via the washer 60.

[0098] This completes all steps of the branching method according to the present invention.

[0099] In the branching method according to the present invention, a sleeve protrusion step S5 is performed using separate jigs to create a state in which the lower end of the sleeve 30 protrudes into the rehabilitation pipe 15 from the lower end of the rubber ring 40, and a sleeve diameter expansion step S7 is performed using separate jigs to bend the portion of the sleeve 30 that protrudes into the rehabilitation pipe 15 radially outward so as to wrap around the portion of the rubber ring 40 that protrudes into the rehabilitation pipe 15, thereby creating a state in which the sleeve 30 is crimped to the rehabilitation pipe 15. Therefore, with the branching method according to the present invention, each jig can be made smaller compared to when these two steps are to be performed with a single jig.

[0100] Although one embodiment of the branching method according to the present invention has been described above, the branching method according to the present invention is not limited thereto.

[0101] For example, the sleeve 30 and nut 50 may be made of a metal other than stainless steel, and the washer 60 may be made of any material other than plastic. In particular, the washer 60 may be made of a metal having the same mechanical strength as the nut 50.

[0102] Furthermore, the pressure rod 112 (upper end portion 112a) of the pressurizer 110, the gripping portion 153 of the rubber ring compression jig 150, and the shaft 155 (upper end portion) of the rubber ring compression jig 150 may have any shape (a shape other than a hexagonal prism) that is easy to grip with a tool such as a wrench. [Explanation of Symbols]

[0103] 10 Branch pipes 11 Master 12 branch pipes 13 Branch pipe flange 14a,14b,14c,14d through hole 15 Rehabilitation pipe 16 Perforation 20 Drilling jig 21 Drill bits 22 axes 30 sleeves 31 Cylindrical part 32 Male threaded section 33a, 33b Notches 40 rubber rings 41a Washer mounting section 41b Overlay part 41c Protrusion 42a Upper inner peripheral surface 42b Tapered section 42c Lower inner peripheral surface 42d Ring section 50 nuts 51 Cylindrical part 52 Female thread section 53a, 53b Notches 60 washers 61a Sleeve insertion section 61b Rubber ring mounting section 70 Branch Unit 80 Base Flange Unit 81 Base flange 82a, 82b First rod 83a, 83b Second rod 84 Insertion port 85a, 85d Bolt holes 85b, 85c Drilled holes 86 Small diameter section 90 Sleeve Covers 91 Cover flange 92 Cylindrical part 93 Insertion port 94a,94b,94c,94d Through hole 95a,95b through hole 96a, 96b Engagement protrusion 97 Scale section 100 Intermediate Plate 101a,101b through hole 102 Mortar-shaped recess 110 Pressurizer 111 Support plate 112 Pressure Rod 112a Upper end 112b Middle part 112c Lower end of cone 113 Guide Section 114a,114b through hole 120 Pressing jig 130 Diameter expansion jig 131 Flange 132 Fixed base 133 Rotating base 134 Rotation Restriction Section 134a First regulated groove 134b Second regulating groove 135 Shaft Cover 136 Shaft 137 Nut 138 Tip 139 Diameter-expanding roller 140 slides 141 Knob 142a,142b through hole 143 Insertion port 144 Insertion slot 145 Insertion opening 150 Rubber Ring Compression Jig 151 Cylindrical part 152 Lid 153 Gripping part 154 Insertion port 155 shaft 156 Rotation restricting section 157a,157b Engagement protrusion 158a, 158b Engagement protrusion

Claims

1. A method for branching a rehabilitation pipe, which is installed in the main pipe, to the side of the branch pipe, in a branch pipe where the main pipe and the branch pipe intersect at a right angle, A rehabilitation pipe perforation step in which a perforation is formed in the rehabilitation pipe using a perforation jig inserted from the branch pipe, A branch unit assembly process for assembling a branch unit comprising a cylindrical metal sleeve and a cylindrical rubber ring attached to the outer circumference of the lower end of the sleeve, The process involves inserting the branching unit from the branch pipe so that the lower end of the rubber ring protrudes from the perforated portion into the rehabilitation pipe, and A step of attaching a push-in jig to the flange of the branch pipe, the push-in jig being able to act on the upper end of the sleeve, A sleeve protrusion step is performed by operating the aforementioned pushing jig so that the lower end of the sleeve protrudes from the lower end of the rubber ring into the rehabilitation pipe, A diameter expansion jig installation step involves replacing a part of the pressing jig attached to the flange with a diameter expansion jig that can act on the lower end of the sleeve, By operating the diameter-expanding jig, the portion of the sleeve that protrudes into the rehabilitation tube is bent radially outward so that the portion of the rubber ring that protrudes into the rehabilitation tube is wrapped around it, and the sleeve and the sleeve that is crimped to the rehabilitation tube form a fixed wall in the sleeve diameter-expanding process. A method characterized by performing the following:

2. The branching unit further comprises a movable wall that is screwed onto the outer surface of the sleeve between the mounting position of the rubber ring and the upper end of the sleeve, After the sleeve diameter expansion process, A rubber ring compression jig installation step involves replacing the remaining portion of the pressing jig attached to the flange and the diameter expanding jig with a rubber ring compression jig that acts on the moving wall, The rubber ring compression process involves operating the rubber ring compression jig to move the movable wall toward the fixed wall, and compressing the rubber ring between the movable wall and the fixed wall. The method according to claim 1, further characterized by performing the following steps.

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