JP7510397B2 - Method for repairing existing drainage pipes and chemical discharge device for use in repairing existing drainage pipes - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act Distribution by email or DVD of a video filmed on October 5, 2020, of an experiment conducted in-house to complete the invention of the method for repairing existing drainage pipes related to this application. [Publications, etc.] On January 15, 2021, a demonstration experiment was conducted at UR Urban Development Corporation's Kiyose Asahigaoka Housing Complex to confirm the effectiveness of the invention of the method for repairing existing drainage pipes related to this application. [Publications, etc.] On July 30, 2021, a demonstration experiment was conducted at UR Urban Development Corporation's Acty Gakuen Nishimachi to confirm the effectiveness of the invention of the method for repairing existing drainage pipes related to this application.

The present invention relates to a method for repairing existing drainage pipes that have deteriorated.

In high-rise buildings such as apartment complexes, wastewater from facilities such as sinks, washrooms, bathrooms, and toilets passes through horizontal branch pipes leading from the rooms in which each facility is installed, and is then discharged into a sewage tank or other facility via a shared drainage standpipe that runs through each floor.

Existing drainage pipes, such as the drainage standpipes of high-rise buildings, can leak due to rust and deterioration caused by breaks over the decades. Various methods are known for repairing and rehabilitating existing drainage pipes to stop leaks. Typical repair methods include the resin lining method, in which the inner surface of the existing drainage pipe is coated with a resin such as epoxy resin to fill in the leaking area, the pipe-in-pipe method, in which a new pipe is inserted inside the existing drainage pipe to ensure a water passage with the new pipe, and the patch method, in which the leaking area of the existing drainage pipe is filled from the outside with a resin or the like.

For example, the following Patent Document 1 discloses a method for rehabilitating a drainage riser that is disposed penetrating a concrete slab that constitutes the slab floor surface of multiple floors, comprising a cutting step of cutting the drainage riser between the current floor to be rehabilitated and the floor above at a predetermined position from the slab floor surface of the current floor and at a predetermined position from the slab ceiling surface of the floor above and removing the connection between them, a penetration part rehabilitation step of polishing and cleaning the inner surface of the slab penetration part of the drainage riser remaining on the slab floor surface of the current floor and/or the slab ceiling surface of the floor above and then forming an epoxy resin film on the inner surface, and a connection part rehabilitation step of joining a new pipe to the part removed in the cutting step.

For example, the following Patent Document 2 discloses a method of repairing the inner surface of an old drainage pipe by inserting a new pipe with a smaller diameter than the old drainage pipe into the old drainage pipe, butt welding the new pipes together from the inside of the pipe, and then filling the gap between the new pipe and the old drainage pipe with a filler such as mortar by pressure injection.

For example, the following Patent Document 3 discloses a method for repairing a running water pipe through which liquid flows, which includes step 1 of attaching a patch member or placing an adhesive on the part of the running water pipe to be repaired; and step 2 of attaching an enclosure cover that waterproofly surrounds and covers the running water pipe to which the patch member is attached or the adhesive is placed, in which the running water pipe is installed inside a building and leakage of liquid from the part to be repaired is stopped from step 1 until the enclosure cover is attached in step 2.

For example, the following Patent Document 4 discloses a method for repairing water leakage from a slab penetration part of an existing drainage pipe that penetrates a slab, comprising the steps of cutting and removing a part of the existing drainage pipe so as to leave a protruding part of the existing drainage pipe that penetrates the slab and protruding from the slab to form a remaining existing drainage pipe, polishing the inner peripheral surface of the remaining existing drainage pipe, preparing a short pipe made of resin having a main part with an outer diameter smaller than the inner diameter of the existing drainage pipe and a large-diameter part with an outer diameter larger than the inner diameter of the existing drainage pipe at one end of the main part, and applying a liquid water-hardening waterproofing agent to at least the outer peripheral surface of the main part of the short pipe, inserting the short pipe into the remaining existing drainage pipe, and adhering the outer peripheral surface to the inner peripheral surface of the remaining existing drainage pipe via the waterproofing agent.

JP 2006-57643 A Publication No. 62-266287 JP 2014-5930 A JP 2019-184047 A

In the case of the leak repair method disclosed in Patent Document 4, a portion of the existing drainage pipe that penetrates the slab is cut and removed so as to leave the protruding portion of the existing drainage pipe that protrudes from the slab, and a short pipe with a larger diameter portion whose outer diameter is larger than the inner diameter of the remaining existing drainage pipe is inserted into the remaining existing drainage pipe from the upper floor side, thereby engaging the short pipe inserted into the remaining existing drainage pipe. With this method, work can only be done from the upper floor side, and work cannot be done if cooperation is not obtained from the residents on the upper floors.

The present invention aims to solve the problems described above by providing a method for repairing existing drainage pipes that allows for easy repair work from the lower floor side.

One aspect of the present invention is a method for repairing an existing drainage pipe, comprising the steps of: preparing a chemical ejection device having an outer tube with a chemical ejection port at its tip and a plunger inserted inside the outer tube; inserting a short repair tube around the outer periphery of the outer tube and retaining it therein; withdrawing the plunger from the outer tube toward the rear end to form a space on the tip side of the outer tube and storing a liquid water-stopping agent in the space; and displaying the state in which the liquid water-stopping agent has been stored in the cut existing drainage pipe and the state in which the short repair tube has been inserted and retained in the outer tube. The method for repairing an existing drain pipe includes the steps of inserting a chemical discharge device in a state into the outer cylinder, pressing a plunger toward the tip of the outer cylinder to discharge a liquid water-stopping agent from the chemical discharge port, and applying the liquid water- stopping agent to a gap formed between the existing drain pipe and the short pipe for repair, removing the chemical discharge device from the existing drain pipe after applying the liquid water-stopping agent to the gap and leaving the short pipe for repair inside the existing drain pipe , and hardening the liquid water-stopping agent applied to the gap . According to this method, water leakage from the existing drain pipe can be repaired easily from the lower floor side.

Another aspect of the present invention is a drug ejection device used for repairing the above-mentioned existing drainage pipe, comprising an outer tube, a plunger, and a plate fixed at a predetermined position on the outer periphery of the outer tube, a tip member for sealing the short repair pipe is arranged at the tip of the outer tube, and the plate has a diameter larger than the outer diameter of the short repair pipe. According to such a drug ejection device, since the tip member for sealing the short repair pipe is arranged at the tip of the outer tube, the drug can be sufficiently applied to the gap formed between the existing drainage pipe and the short repair pipe without leaking into the short repair pipe, and since the plate has a diameter larger than the outer diameter of the short repair pipe, the short repair pipe can be kept on the plate. Furthermore, when the plate has a diameter larger than the inner diameter of the existing drainage pipe, leakage of the drug outside the existing drainage pipe during repair of the existing drainage pipe can be suppressed.

According to the present invention, existing drainage pipes can be repaired easily from the lower floor side.

FIG. 1 is a process explanatory diagram for explaining preparation of a cut existing drainage pipe 50 which is to be the subject of construction of the existing drainage pipe. FIG. 2 is a schematic cross-sectional view of the drug ejection device 10 used for repairing an existing drainage pipe. FIG. 3 is an explanatory diagram for explaining a state when the short repair tube 20 is disposed on the medicine ejection device 10. As shown in FIG. FIG. 4 is a process explanatory diagram for explaining the repair method for an existing drainage pipe according to the first embodiment. FIG. 5 is a process explanatory diagram illustrating a method for connecting a new pipe 60 to an existing drainage pipe 50 that has been repaired by a method for repairing an existing drainage pipe.

The method for repairing an existing drainage pipe and the chemical ejection device used for repairing an existing drainage pipe according to the present invention will be described below with reference to the drawings.

First, referring to FIG. 1, the process of preparing a cut existing drainage pipe 50 (hereinafter also simply referred to as the existing drainage pipe 50) to be used in the repair method of an existing drainage pipe of this embodiment will be described. In FIG. 1, 52 is an existing drainage standpipe that passes through each floor of a high-rise building, f is the slab of the upper floor to be repaired for leakage, and c is the slab of the lower floor, and these slabs are formed as concrete slabs, for example. Also, h1 and h2 are leakage points that are holes that have occurred in the existing drainage pipe 50 in the slab f that is the cause of the leakage to be repaired. The leakage points h1 and h2 occur inside the slab f where the existing drainage pipe 50 is not exposed, so they cannot be repaired directly from the outside. Also, r is dirt such as rust that has occurred inside the existing drainage pipe 50. Each element in FIG. 1 is a schematic representation of a longitudinal cross section of the drainage standpipe 52. Also, 70 is a driver equipped with a core bit 69.

First, as shown in FIG. 1(a), a drain pipe piece 51, which is a part of the drainage rise pipe 52 between cross section x1 and cross section x2 of the existing drainage rise pipe 52 that passes through the residential area where the leak repair is to be performed, is cut and removed, and the existing cut drain pipe 50 that remains after the drain pipe piece 51 is cut and removed is formed, as shown in FIG. 1(b).

The inner surface of the existing drainage pipe 50 is covered with filth such as rust and sludge that has developed due to water flowing through the existing drainage pipe, although the degree of this varies depending on the number of years of residence and the environment in which it is used. It is preferable to remove such filth such as rust and sludge that has adhered to the inner surface of the existing drainage pipe during repair work. To this end, as shown in FIG. 1(c), the inner surface of the existing drainage pipe 50 is polished and flattened using a driver 70 equipped with a polishing member such as a core bit 69.

In this manner, the cut existing drainage pipe is prepared as the target of the method for repairing the existing drainage pipe. The method for repairing the existing drainage pipe 50 prepared in this manner according to this embodiment is described below.

First, the drug ejection device used in the embodiment of the method for repairing an existing drainage pipe will be described with reference to FIG. 2. FIG. 2 is a schematic cross-sectional view of a syringe-shaped drug ejection device 10 used for repairing an existing drainage pipe. In FIG. 2, 1 is an outer tube (cylinder), 2 is a plunger, 3 is a sealing member, 4 is a tip member equipped with a drug ejection port D, 5 is a rear end member, and 6 is a plate. From the viewpoint of durability, the outer tube 1 and the plunger 2 are preferably made of metal.

A tip member 4 equipped with a chemical discharge port D is disposed at the tip of the cylindrical outer tube 1. As shown in FIG. 3, the tip member 4 is provided to seal the tip of the repair short pipe 20 described below, thereby applying the chemical to the gap formed between the existing drain pipe and the repair short pipe without leaking the chemical discharged from the chemical discharge port D into the repair short pipe. Such a tip member is preferably formed from an elastic material such as rubber, elastomer, or sponge that can be deformed by compression and seal the tip of the repair short pipe 20.

A rear end member 5 is provided at the rear end of the outer tube 1 to guide the plunger 2 so that it can move up and down the page. The rear end member 5 acts as a guide to support the moving plunger 2. A seal member 3 is provided at the tip of the plunger 2, which slides along with the movement of the plunger 2 while sealing the gap with the inner surface of the outer tube 1. The seal member is preferably made of an elastic material such as rubber, elastomer, or sponge. A plate 6 is fixed at a predetermined position on the outer periphery of the outer tube 1.

As shown in FIG. 3, the plate 6 is provided to insert the repair short pipe 20 used for repairing the existing drain pipe into the outer cylinder 1 of the drug ejection device 10 and retain it on its outer periphery. The plate 6 may be adjustable to move in the vertical direction. By adjusting the position of the plate 6, the position of the repair short pipe 20 can be adjusted according to the position and length of the repair location of the existing drain pipe 50. Such a plate 6 has a diameter larger than the outer diameter of the repair short pipe 20, so that the repair short pipe 20 can be placed and retained on the plate 6. In addition, when the plate 6 has a diameter larger than the inner diameter of the existing drain pipe 50, as described later, the lower end of the existing drain pipe 50 can be blocked during repair of the existing drain pipe 50, thereby suppressing leakage of the drug outside the existing drain pipe 50. The material of such a plate is not particularly limited, but examples include resin, various metals, rubber, etc. Instead of using such a plate, the repair short pipe can be inserted and secured to the outer periphery of the outer tube by temporarily adhering it to the tip member 4 with a weak adhesive or the like, and then secured to the outer periphery.

Next, the method of repairing an existing drainage pipe of this embodiment using such a drug ejection device 10 will be described in detail with reference to the process diagram of FIG. 4. In FIG. 4, 50 is the existing drainage pipe that has been cut and prepared as shown in FIG. 1. Also, f is the slab of the upper floor where the repair work will be performed. Also, h1 and h2 are leaking points that are holes that have occurred in the existing drainage pipe 50 to be repaired within the slab f. Also, 30 is a liquid water-stopping agent, 31 is a hardened water-stopping agent, and 40 is a cup that stores the liquid water-stopping agent 30. Each element in FIG. 4 is a schematic representation of a longitudinal cross section of the existing drainage pipe 50.

As shown in FIG. 4(b), the leak points h1 and h2 are located inside the slab f where the existing drainage pipe 50 is not exposed. Therefore, unless the slab f is destroyed, the leaks from the leak points h1 and h2 cannot be repaired directly from the outside.

In the method for repairing an existing drainage pipe of this embodiment, as shown in FIG. 1, an existing drainage pipe 50 is prepared in advance by cutting the existing drainage pipe so as to leave the existing drainage pipe penetrating the slab f. Preferably, the inner surface of the cut existing drainage pipe 50 is polished and flattened before construction. In this way, the cut existing drainage pipe 50 to be repaired is prepared in advance.

Then, the drug ejection device 10 is prepared, and as shown in FIG. 3, a repair short pipe 20 used to repair the existing drainage pipe 50 is inserted into the outer cylinder 1. The repair short pipe 20 is then placed on a plate 6 fixed at a predetermined position around the outer cylinder 1 and is retained on its outer periphery. The material of the repair short pipe is not particularly limited, but it may be made of a resin material such as rigid polyvinyl chloride resin, or may be a metal pipe. It is particularly preferable that the short pipe be made of a resin such as rigid polyvinyl chloride resin, since it does not cause corrosion due to contact between dissimilar metals and is less likely to rust the existing metal drainage pipe.

Then, as shown in FIG. 4(a), the plunger 2 of the medicine ejection device 10 is pulled out toward the rear end. The liquid waterproofing agent 30 is then stored in the space at the tip of the outer cylinder 1 that is formed by pulling out the plunger 2. Specifically, for example, the liquid waterproofing agent 30 stored in the cup 40 is poured into the space at the tip of the outer cylinder 1, so that the liquid waterproofing agent 30 is stored in the space at the tip of the outer cylinder 1.

The water-stopping agent fills and seals the gap formed between the cut existing drain pipe 50 and the inserted repair short pipe 20, thereby preventing water from entering the gap from the leaking point, and bonds the existing drain pipe 50 and the repair short pipe 20 together. There are no particular limitations on the thickness of the hardened water-stopping agent, but it is preferably, for example, 0.5 to 10 mm, or even 1 to 5 mm.

As the liquid water-stopping agent, any water-stopping agent with low water permeability that can fill and bond the gap by adhering the outer peripheral surface of the short pipe for repair to the inner peripheral surface of the existing drain pipe via the water-stopping agent when filling the gap can be used without any particular limitation. Specific examples of such water-stopping agents include, for example, one-component polyurethane resin water-stopping agents and two-component polyurethane resin water-stopping agents that are liquid or viscous before contacting water and fill and seal the gap by hardening. In the implementation of the repair method of this embodiment, a one-component polyurethane resin water-stopping agent, particularly a water-curable one-component polyurethane resin water-stopping agent that hardens in a predetermined time by mixing with a predetermined amount of water and whose hardened product exhibits rubber elasticity, is preferred in that it hardens in the presence of water and is a non-foamed or low-foamed polyurethane elastomer with a foaming ratio of 1 or more, because it maintains rigidity without shrinkage during hardening and provides high water-stopping and adhesive effects. A specific example of such a water-curable one-component polyurethane resin waterproofing agent is Hycel (registered trademark) OH (manufactured by Toho Chemical Industry Co., Ltd.). In particular, when cement is blended with the water-curable one-component polyurethane resin, this is preferred in terms of improving the rapid curing properties. In this case, the waterproofing agent hardens in, for example, about 30 to 600 seconds. After a certain period of time has passed, a hardened waterproofing agent is formed.

Then, as shown in FIG. 4(b), the chemical ejection device 10 is inserted into the existing drain pipe 50 with the repair short pipe 20 inserted and retained in the outer tube 1, and as shown in FIG. 4(c), the plate 6 is set to abut against the lower end of the existing drain pipe 50. Note that in this embodiment, liquid waterproofing agent 30 is stored in advance in the space at the tip of the outer tube 1, but liquid waterproofing agent 30 may be supplied to the space at the tip of the outer tube 1 after inserting the chemical ejection device 10 that does not store liquid waterproofing agent 30.

As shown in FIG. 4(d), the plunger 2 is pushed in the direction of the arrow toward the tip of the outer tube 1, which has liquid water-stopping agent 30 stored at its tip, to eject the liquid water-stopping agent 30 from the agent ejection port D. At this time, because the tip of the repair short pipe 20 is sealed with the tip member 4, the liquid water-stopping agent 30 ejected from the agent ejection port D does not leak into the repair short pipe 20, and the agent can be applied to the gap formed between the existing drain pipe and the repair short pipe.

In this way, as shown in FIG. 4(e), the liquid waterproofing agent 30 is applied so as to fill the gap formed between the existing drain pipe 50 and the repair short pipe 20. At this time, if the lower end of the existing drain pipe 50 is blocked by the plate 6, the liquid waterproofing agent 30 that has been filled will not leak out of the existing drain pipe 50.

By applying the liquid water-stopping agent 30 in this manner, the gap formed between the inner circumferential surface of the existing drainage pipe 50 and the outer circumferential surface of the repair short pipe 20 is filled with the liquid water-stopping agent 30. At this time, the leaking points h1 and h2 are also filled with the liquid water-stopping agent 30.

Then, a water-curing liquid waterproofing agent 30 is filled into the gap between the inner circumferential surface of the existing drain pipe 50 and the outer circumferential surface of the repair short pipe 20, and then the liquid waterproofing agent 30 is left for a predetermined time, causing the liquid waterproofing agent 30 to harden, forming a hardened waterproofing agent 31, as shown in FIG. 4(f). Then, as shown in FIG. 4(g), the drug ejection device 10 is removed from the existing drain pipe 50. At this time, the repair short pipe 20 is adhered to the inner circumferential surface of the existing drain pipe 50 by the hardened waterproofing agent 31.

In this way, as shown in FIG. 4(h), the leak points h1, h1 of the existing drainage pipe 50 are plugged and repaired, completing the repair of the existing drainage pipe in this embodiment.

After repairing the leaking points h1 and h2 in the slab f, a part of the existing drain pipe is cut to fill the part where the existing drain pipe piece was removed, and a new pipe of the same length as the part where the existing drain pipe was removed is prepared and connected to the removed part. Specifically, for example, as shown in FIG. 5(a), a new pipe 60 of the same length as the part where the existing drain pipe piece was removed from the existing drain pipe is prepared, and the new pipe 60 is fitted as shown in FIG. 5(b), and the joint with the existing drain pipe 50 and the joint with the cut existing drain pipe 58 on the slab c side are watertightly treated, and then fixed with a coupling member 59 as shown in FIG. 5(c). In such a connection, it is preferable to easily connect the pipes using a coupling member that connects the pipes by reducing the diameter. As such a coupling member, for example, a coupling member that butts the end faces of the piping and connects the pipes by reducing the diameter, specifically, for example, a Strab coupling (registered trademark, manufactured by Showbond Coupling Co., Ltd.) is preferably used. In this way, by connecting a new pipe, the section that was removed from the existing drainage pipe can be replaced and the drainage channel can be restored.

According to the method for repairing an existing drainage pipe of this embodiment described above, leaking points in the unexposed parts of an existing drainage pipe that penetrate the slab can be repaired quickly and easily without the trouble of destroying the slab.

1 Outer tube 2 Plunger 3 Seal member 4 Tip member 5 Rear member 6 Plate 10 Drug ejection device 20 Repair short pipe 30 Water stop agent 31 Hardened water stop agent 40 Cup 50, 58 Cut existing drain pipe 51 Drain pipe piece 52 Drain standpipe 59 Coupling member 60 New pipe 69 Core bit 70 Driver c, f Slab D Drug ejection port h1 Water leak location h2 Water leak location

Claims (3)

A method for repairing an existing drainage pipe, comprising:
A step of preparing a medicine ejection device including an outer cylinder having a medicine ejection port at a tip thereof and a plunger inserted into the outer cylinder;
a step of inserting a repair short pipe into the outer periphery of the outer cylinder and retaining it ;
a step of withdrawing the plunger from the outer cylinder toward the rear end to form a space on the front end side of the outer cylinder, and storing a liquid waterproofing agent in the space;
A step of inserting the chemical ejection device into the cut existing drainage pipe in a state where the liquid waterproofing agent is stored and the repair short pipe is inserted and retained in the outer cylinder ;
a step of pushing the plunger toward the tip of the outer cylinder to discharge the liquid waterproofing agent from the agent discharge port , and applying the liquid waterproofing agent to a gap formed between the existing drain pipe and the short pipe for repair;
After applying the liquid waterproofing agent to the gap , the repair short pipe is left in the existing drainage pipe, and the chemical ejection device is removed from the existing drainage pipe;
curing the liquid waterproofing agent applied to the gap;
A method for repairing an existing drainage pipe, comprising : Used for repairing the existing drainage pipe according to claim 1,
The device includes the outer cylinder, the plunger, and a plate fixed to a predetermined position on the outer periphery of the outer cylinder,
A tip member for sealing the repair short pipe is provided at the tip of the outer cylinder,
A chemical ejection device used for repairing an existing drainage pipe, wherein the plate has a diameter larger than the outer diameter of the short pipe for repair. The chemical ejection device used for repairing an existing drainage pipe according to claim 2 , wherein the plate has a diameter larger than an inner diameter of the existing drainage pipe.

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