Water stop plug

Abstract

Water stop plug using cylindrical bag body excellent in water stop property capable of effectively exerting pressure contact force toward pipe wall without using hard and undeformable core Suga such as metals inconvenient for transportation SOLUTION: The bag is provided with a bag body 1 which is cylindrically expanded by injecting a fluid from an injection port 1e into a sealed space 1c to form a hollow part 1f inside, a partition sheet 2 which is made of a soft material and has an opening 1f smaller than the hollow part 2a, and a bypass pipe 3 connected to the opening 2a. the partition sheet 2 is watertightly attached to the cylindrical bag body 1 so that the opening 2a faces the hollow part 1f. In the cylindrical bag body 1, an inner cylinder part side 1b forming an inner peripheral 1a and an outer cylinder part side 1c forming an outer peripheral 1c are opposed to each other across a sealed space side 1b, and a large number of reinforcing member side 1a connecting the inner cylinder part side 1d and the outer cylinder part side wall are provided in the sealed space side wall.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water stop plug (also called a water stop ball or a water stop valve) used to temporarily stop water in piping such as building water distribution pipes and water and sewerage pipes. [Background technology]

[0002] Various types of water stop plugs have been known for temporarily shutting off the piping in the construction area when replacing a portion of a pipe such as a building water distribution pipe or a water supply and sewerage pipe, or when working inside a manhole. The applicants have previously disclosed in Patent Documents 1 and 2 water stop plugs with a structure in which a ring-shaped hollow tube made of an elastic material is placed around the outer periphery of a cylindrical, hard core pipe.

[0003] In the water stop plugs shown in these patent documents, the diameter of the core tube is made large to minimize the expansion width of the hollow tube (the difference in the radial direction between when the hollow tube is contracted and when it is expanded). This makes it possible to reduce the amount of pressurized fluid injected, and as a result, to shorten the injection time. Furthermore, by making the diameter of the core tube large and reducing the expansion width, it is possible to reduce the stress generated in the hollow tube itself, reducing fatigue of the hollow tube and thereby extending the product life. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-193312 [Patent Document 2] Japanese Patent Publication No. 2021-193313 Summary of the Invention [Problem to be solved by the invention]

[0005] The ring-shaped hollow tube used in waterstop plugs is made of a flexible material that can expand and contract, and when pressurized fluid is injected, it expands not only toward the outer periphery but also toward the inner periphery. Therefore, if the hollow tube alone is expanded inside the pipe as a waterstop plug without a rigid core tube on the inner periphery, the outer surface of the hollow tube will eventually press against the pipe wall, thereby preventing water from entering. However, even if the pressure is further increased by continuing to inject pressurized fluid to further improve waterstop performance, the hollow tube continues to expand toward the inner periphery, preventing effective increase in the pressure toward the outer periphery. In other words, in waterstop plugs with a ring-shaped hollow tube structure, it is necessary to limit the expansion of the hollow tube's inner periphery with a rigid core tube in order to effectively increase the pressure and improve waterstop performance.

[0006] Therefore, in conventional watertight plugs using a ring-shaped hollow tube, a cylindrical core tube made of a hard, undeformable material such as metal is placed on the inner periphery of the hollow tube to limit the expansion of the hollow tube toward the inner periphery. In this way, when the hollow tube expands toward the inner periphery and presses against the core tube, it receives a reaction force from the core tube, which limits further expansion toward the inner periphery, making it possible to effectively apply the pressing force toward the outer wall and improving watertight performance.

[0007] However, using a hard core pipe such as a metal increases the overall weight, making it inconvenient to transport. Moreover, when transporting a cylindrical core pipe through a manhole or the like into a pipe such as a sewer pipe, it can be physically difficult to transport the core pipe as is. If the core pipe is divided into multiple smaller parts, it can be transported through a manhole into the pipe, but in that case, it is necessary to assemble the divided parts inside the pipe, which is troublesome. In particular, if the difference in diameter between when the hollow tube attached to the outer periphery of the core tube is contracted and when it is expanded is reduced, for example, in order to reduce the amount of fluid injected, it is necessary to increase the diameter of the core tube, which makes transportation and assembly into the piping even more difficult and inconvenient.

[0008] Therefore, the present invention aims to provide a water-stopping plug with excellent water-stopping performance that does not use a core tube made of a hard, undeformable material such as metal, yet limits the expansion of the hollow tube toward the inner circumference, thereby effectively exerting a pressure force toward the outer pipe wall. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following technical means. That is, the water stop plug of the present invention is a water stop plug for temporarily stopping water flow in a pipe, and includes a bag body in which a sealed space is formed from a flexible soft material and which expands into a cylindrical shape to form a hollow portion on the inside when a fluid is injected into the sealed space through an injection port, a partition sheet made of a flexible soft material and formed with an opening having a diameter smaller than that of the hollow portion, and a bypass pipe connected to the opening, the partition sheet is watertightly attached to the cylindrical bag body with the opening facing the hollow portion, the cylindrical bag body has an inner tubular portion forming an inner peripheral wall and an outer tubular portion forming an outer peripheral wall facing each other across the sealed space, and a number of reinforcing members are provided within the sealed space to connect the inner tubular portion and the outer tubular portion. [Effects of the Invention]

[0010] According to the present invention, the bag body and partition sheet of the watertight plug are formed using a flexible material that can be bent, so that it can be folded up small and transported, and therefore it can be easily transported to the pipe to be watertight even if the diameter of the transport entrance (manhole, etc.) is small. The watertight plug of the present invention has a structure (drop stitch structure) in which the outer and inner tubular portions of the inflated tubular bag face each other across a sealed space, and multiple reinforcing members are provided within the sealed space to connect the inner and outer tubular portions. When fluid is pressurized and injected into the sealed space to further expand the tubular bag, excessive expansion that would increase the distance between the outer and inner tubular portions is limited by the reinforcing members, thereby preventing the outer and inner tubular portions from deforming in a direction that separates them. This prevents excessive inward deformation of the inner tubular portion when the bag expands to form a cylindrical body, even without a hard core tube (e.g., metal) that supports the inner tubular portion of the bag from the inside, thereby firmly maintaining the shape of the cylindrical body. This effectively increases the pressure on the outer tubular portion, allowing the entire outer periphery of the outer tubular portion to strongly press against the inner surface of the pipe, thereby sealing off water.

[0011] In the above invention, a soft cover body may be provided on the outer cylindrical part of the cylindrical bag body to fill any gaps between the outer cylindrical part and the wall surface of the pipe. This allows the soft cover body to fill any gaps between the outer cylindrical part and the wall surface of the pipe, even if the inner wall surface of the pipe is uneven, or if the cylindrical bag body does not become a perfect cylinder but expands into, for example, a rectangular (approximately cylindrical) shape, thereby maintaining watertight performance. In the above invention, a flange portion having a plurality of small holes for connection formed therein may be provided at one end of the bypass pipe, and a plurality of small holes corresponding to the positions of the small holes in the flange portion may be provided around the opening in the partition sheet. This allows the partition sheet to be connected to a bypass pipe of an appropriate length with fastening members such as bolts and nuts. In the above invention, the bypass pipe may be formed of a soft material and one end thereof may be welded to the periphery of the opening in the partition sheet. This allows the bag body, the partition sheet, and the bypass pipe to be transported and stored in a folded state. [Brief explanation of the drawings]

[0012] [Figure 1]1 is a cross-sectional view showing a water stop plug according to an embodiment of the present invention in a state in which the water stop plug is expanded inside a pipe. [Figure 2] FIG. 10 is a front view showing the water stop plug in a deflated state after fluid has been removed from the water stop plug. [Figure 3] FIG. 10 is a cross-sectional view showing another embodiment of the water stop plug according to the present invention. [Figure 4] FIG. 10 is a cross-sectional view showing another embodiment of the water stop plug according to the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing another embodiment of the water stop plug according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

[0013] The water stop plug of the present invention is described below with reference to the drawings. When temporarily stopping water flowing into a construction area during plumbing work or the like, the water stop plug of the present invention does not completely stop all of the water flow, but stops the water in the construction area while allowing a portion of the water to be discharged downstream via a bypass pipe.

[0014] (First Example) FIG. 1 shows a cross section of a watertight plug according to one embodiment of the present invention inserted into a pipe P and inflated. The watertight plug A includes a bag body 1 that inflates into a generally cylindrical shape (tubular body) with a hollow space 1f inside when a fluid such as air (or water) is injected into the interior. Specifically, the bag body 1 has a structure (drop-stitch structure) including an outer tube 1a forming the outer peripheral wall of the tubular body, an inner tube 1b forming the inner peripheral wall, a sealed space 1c formed between the outer tube 1a and the inner tube 1b, and numerous (countless) reinforcing members 1d connecting the outer tube 1a and the inner tube 1b so as to be distributed approximately uniformly around the entire circumference within the sealed space 1c. An injection port 1e for injecting a fluid into the sealed space 1c is provided in a side wall 1g of the bag body 1.

[0015] The bag body 1 is preferably formed from, for example, PVC (polyvinyl chloride) containing reinforcing fibers, but is not particularly limited to any particular material as long as it is a flexible material that is bendable in its deflated state before the fluid is injected and has the strength to withstand the pressure when the fluid is injected under pressure.

[0016] The reinforcing member 1d is made of polyester fiber in thread form, but is not particularly limited as long as it is a material strong enough to not stretch or break when fluid is pressurized and filled into the bag body 1, and is a material that can prevent the outer tubular portion 1a and the inner tubular portion 1b from deforming in directions separating them from each other and maintain their substantially cylindrical shape. There are also no particular limitations on the thickness or shape of the reinforcing member 1d, and it may be, for example, a flat, ribbon-like reinforcing member.

[0017] The outer diameter of the outer cylindrical portion 1a is set so that the outer peripheral surface of the outer cylindrical portion 1a can be pressed against the inner peripheral surface of the pipe P when the bag body 1 is expanded into a cylindrical shape. A partition sheet 2 is watertightly attached to one end of the bag body 1 by welding. The partition sheet 2 is made of PVC (polyvinyl chloride) containing reinforcing fibers, which is a flexible, soft material like the bag body 1, but there are no particular restrictions on the material as long as it can be watertightly welded to the bag body 1 and can withstand the water pressure of running water.

[0018] An opening 2a having a smaller diameter than the hollow portion 1f is provided in the partition sheet 2 at a position facing the hollow portion 1f (in this embodiment, at the center of the hollow portion 1f), and the bypass pipe 3 can be watertightly connected to this opening 2a. That is, a flange 3a having a plurality of small holes 3b is provided at the end of the bypass pipe 3, and small holes 2b are also provided around the opening 2a of the partition sheet 2 at positions corresponding to the small holes 3b. The partition sheet 2 is sandwiched between the flange 3a and a ring-shaped presser plate 8 together with a sealing material 7 such as packing, and fastened with fastening members 9 such as bolts and nuts, thereby enabling a watertight connection. Note that the bypass pipe 3 is preferably a bendable rubber or resin pipe, but there are no particular restrictions on its material, length, or shape as long as it can be easily transported in and out and can be connected to the opening 2a.

[0019] Next, a method of using the water stop plug A configured as above will be described. The water stop plugs A of this embodiment are installed in both the upstream and downstream piping P (only one is shown in the drawing) on ​​either side of the construction area, and are used to form a bypass flow path by connecting a bypass pipe 3 to the opening 2a of each water stop plug.

[0020] When attaching the watertight plug A to the pipe P, as shown in Figure 2, the bypass pipe 3 is removed, and the bag body 1, which is not filled with fluid and is in a deflated state, is carried into the pipe P through a carry-in / out opening such as a manhole.

[0021] A pipe 5 from a pressurized fluid supply source 4 is connected to the fluid injection port 1e of the watertight plug A carried into the piping P, and air is pressurized and injected as a fluid into the sealed space 1c of the bag body 1, thereby expanding the bag body 1 into a cylindrical shape and pressing the outer wall of the outer cylindrical portion 1a against the inner wall surface of the piping P.

[0022] Water stop plugs A are attached to the upstream and downstream pipes P, and bypass pipes 3 are watertightly connected to the openings 2a of each water stop plug to form a bypass flow path. This allows piping work to be carried out without blocking the flow of water in the pipes.

[0023] In the watertight plug A of the present invention, the outer tubular portion 1a and the inner tubular portion 1b of the bag body 1 are connected at multiple locations around the entire circumference by reinforcing members 1d, which prevents the outer tubular portion 1a and the inner tubular portion 1b from deforming in a direction that separates them from each other when the bag body 1 is expanded. This allows the bag body 1 to firmly maintain its cylindrical shape without a rigid core tube supporting it from the inside, and the entire outer circumferential surface of the outer tubular portion 1a can be pressed against the inner surface of the piping P to provide a watertight seal.

[0024] Furthermore, since the bag 1 is inflated by injecting a fluid under pressure into the sealed space 1c formed between the outer cylindrical portion 1a and the inner cylindrical portion 1b, it can be inflated in a short time by injecting a small amount of fluid, thereby improving work efficiency. In addition, by removing the fluid, the bag 1 can be deflated together with the partition sheet 2 and folded compactly, making it convenient for transportation and storage.

[0025] (Second Example) 3 is a cross-sectional view of a water stop plug B according to another embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 2 are designated by the same reference numerals and will not be described further. In this embodiment, a rubber cover 6 having a substantially L-shaped cross section is provided so as to cover the entire circumference of the outer tubular portion 1a of the inflated bag body 1 and the side wall 1g at one end. The rubber cover 6 is made of a material such as natural rubber or synthetic rubber that has flexibility that allows the bag body 1 to bend when deflated, and is adhered to the outer tubular portion 1a and the side wall 1g of the bag body 1. Alternatively, the rubber cover 6 may be made separate from the bag body 1 and attached later so as to cover the bag body 1 while it is being inflated into a cylindrical shape. By using this rubber cover 6, even if irregularities or gaps occur in the piping P or the outer cylindrical portion 1a of the bag body 1, the rubber cover 6 fills in the irregularities and gaps, thereby maintaining stable watertightness.

[0026] (Third Example) 4 is a cross-sectional view of a water stop plug C according to another embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 2 are designated by the same reference numerals and description thereof will be omitted. In this embodiment, the bypass pipe 3' is made of the same material as the partition sheet 2. That is, one end of the bypass pipe 3' is made of a flexible, soft material, reinforced fiber-reinforced PVC (polyvinyl chloride), and is connected to the opening 2a by welding it to the partition sheet 2. Therefore, the bag body 1, partition sheet 2, and bypass pipe 3' can all be transported and stored together in a folded state.

[0027] As explained in the method of using the water stop plug A, water stop plugs C are installed in the piping P on both the upstream and downstream sides of the construction section, and a bypass pipe 3' is connected to the opening 2a of each water stop plug to form a bypass flow path by simply connecting the end of the bypass pipe 3' connected to the upstream water stop plug C and the end of the bypass pipe 3' connected to the downstream water stop plug C together via a joint (not shown).

[0028] (Fourth Example) 5 is a cross-sectional view of a water stop plug D according to another embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 2 are designated by the same reference numerals and will not be described further. In this embodiment, a bypass pipe 3'' is used that has the same drop stitch structure as the bag body 1. That is, one end of the bypass pipe 3'' is welded to the partition sheet 2, forming a sealed space 3c, and the outer tubular portion 3a and the inner tubular portion 3b are arranged opposite each other with the sealed space 3c in between. A number of reinforcing members 3d that connect the inner tubular portion 3b and the outer tubular portion 3a are provided within the sealed space 3c. An injection port 3e is provided in the outer tubular portion 3a for injecting a fluid into the sealed space 3c, and the fluid is injected under pressure to expand it into a substantially cylindrical shape, thereby forming a straight bypass pipe 3''.

[0029] In this embodiment, the bypass pipe 3'' can also be transported in a deflated state and expanded inside the piping P, so that the straight bypass pipe 3'', which is shaped to be less likely to clog, can be easily transported and used. In this embodiment, too, the end of the bypass pipe 3'' connected to the upstream water-stopping plug D and the end of the bypass pipe 3'' connected to the downstream water-stopping plug D are butt-connected via a joint (not shown).

[0030] The above describes typical examples of the present invention, but the present invention is not necessarily limited to the above-described embodiments, and can be modified or changed as appropriate within the scope of the claims, while achieving its objectives. [Industrial Applicability]

[0031] The present invention can be used as a water stop plug that temporarily stops water flow in piping such as building water distribution pipes and water and sewerage pipes. [Explanation of symbols]

[0032] A, B, C water stop plug P Pipe to be watertight 1 bag body 1a Outer cylinder 1b Inner cylinder part 1c Confined space 1d Reinforcement member 1e inlet 1f Hollow part 1g side wall 2 Partition sheet 2a aperture 3,3',3'' bypass pipe 6 Cover body

Claims

1. A water stop plug that temporarily stops water flow in a pipe, a bag body in which a sealed space is formed from a flexible soft material, and which expands into a cylindrical shape by injecting a fluid into the sealed space through an injection port to form a hollow portion inside; a partition sheet made of a flexible soft material and having an opening with a diameter smaller than the diameter of the hollow portion; a bypass pipe connected to the opening, the partition sheet is attached to the cylindrical bag body in a watertight manner so that the opening faces the hollow portion, The tubular bag body has an inner tube portion that forms the inner wall and an outer tube portion that forms the outer wall, which face each other across the sealed space, and a water-stop plug in which a number of reinforcing members are provided within the sealed space to connect the inner tube portion and the outer tube portion.

2. The water stop plug according to claim 1, wherein a soft cover body is provided on the outer cylindrical part of the cylindrical bag body to fill a gap between the outer cylindrical part and the wall surface of the pipe.

3. 2. The water stop plug according to claim 1, wherein a flange having a plurality of small holes for connection is provided at one end of the bypass pipe, and a plurality of small holes corresponding to the positions of the small holes in the flange are provided around the opening of the partition sheet.

4. 2. The watertight plug according to claim 1, wherein the bypass pipe is made of a flexible soft material and one end of the bypass pipe is welded to the periphery of the opening in the partition sheet.

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