Water stop plug

Abstract

To provide a water stop plug with a simple constitution which can be mounted onto a pipe-line inner part with a strong grip force so as to exhibit a high water stop effect.SOLUTION: A water stop plug is constituted with a cylindrical core pipe 1, an expandable hose 2 which is spirally wound on an outer circumferential surface of the core pipe 1, an annular plate 6 attached onto one-side end surface of the core pipe, and a closing plate 5 which is attached onto the other-side end surface of the core pipe 1 and closes the end surface. Therein, the hose 2 has one end on which a pressure fluid injection port 3 is provided, at the same time, has the other end which is tightly closed, further is arranged in such a state as to be sandwiched between the annular plate 6 and the closing plate 5, and pressure fluid is injected into the hose 2 to expand the hose, thereby, a circumferential surface of the hose is abutted onto an inner wall surface of pipe line of water-stop object to perform water stop.SELECTED DRAWING: Figure 2

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 from entering piping such as building water distribution pipes and water supply and sewerage pipes. [Background technology]

[0002] When replacing part of a pipe such as a building water supply pipe or a water supply and sewerage pipe, or when working inside a manhole, water stop plugs with a structure in which a cylindrical hollow tube made of an elastic material is arranged around a metal core tube have traditionally been used to temporarily shut off the pipe in the work area (see Patent Documents 1 and 2).

[0003] In the waterstop plugs disclosed in these patent documents, the diameter of the core tube is made large, thereby making it possible to reduce the expansion width of the hollow tube (the radial difference between when the hollow tube contracts and when it expands), which has the advantage of making it possible to reduce the amount of pressurized fluid injected, thereby shortening the injection time and reducing fatigue of the hollow tube, thereby extending its service life. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-193312 A [Patent Document 2] JP 2021-193313 A Summary of the Invention [Problem to be solved by the invention]

[0005] In pipes with a large water flow rate, strong water pressure is applied to the water stop plug in the axial direction of the pipe. In such cases, a water stop plug with high water stop performance and strong gripping power against the inner wall of the pipe is required. Effective ways to improve water stop performance are to increase the length of the hollow tube in the axial direction of the pipe to increase the contact surface (friction surface) between the cylindrical hollow tube and the pipe wall, or to increase the filling pressure of the pressurized fluid filled into the hollow tube. However, the longer the cylindrical hollow tube is in the axial direction of the piping, the more difficult it becomes to process a hollow tube with excellent pressure resistance, and the higher the cost becomes.In addition, the longer the hollow tube is, the greater the amount of pressure fluid injected and the greater the load on the hollow tube, increasing the risk of it bursting, so there is a limit to the axial length and also to how much the filling pressure can be increased. Therefore, Patent Document 2 discloses a method of arranging multiple cylindrical hollow tubes with a short axial length in series, as shown in Figures 8 and 9. This method has the advantage that the contact surface of the multiple hollow tubes with the pipe wall is increased overall, improving water-stopping performance while reducing the load on the hollow tubes. However, on the other hand, there are drawbacks in that the structure becomes more complicated as the number of hollow tubes increases, and individual injection ports for injecting pressurized fluid into the hollow tubes are required, further complicating the overall structure including the pipes for connection.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS The present invention aims to solve the above problems and provide a water stop plug with a simple structure that can be attached to the inside of a pipe with a strong gripping force and exhibits a high water stop effect. [Means for solving the problem]

[0007] 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 comprises a cylindrical core tube, an expandable hose spirally wound around the outer circumferential surface of the core tube, an annular plate attached to one end face of the core tube, and a closing plate attached to the other end face of the core tube to close said end face, The hose is provided with a pressurized fluid injection port at one end and a sealed other end, and is positioned between the annular plate and the closing plate. The hose is configured so that by injecting pressurized fluid into it and expanding it, the circumferential surface of the hose is pressed against the inner wall surface of the pipe to be sealed, thereby sealing off the water. Effect of the Invention

[0008] In the water stop plug of the present invention, when a pressurized fluid is injected into a single spirally wound hose (hollow tube) and it expands, not only the hose peripheral surface parts that contact the inner wall surface of the pipe and the outer circumferential surface of the core tube, but also the hose peripheral surface parts (hose side parts) where adjacent hoses contact each other are present, so that the spiral hollow tube supports the filled pressurized fluid with a larger surface area than a cylindrical hollow tube. Therefore, the hollow tube has better pressure resistance than a cylindrical hollow tube, can be used even when filled with pressurized fluid at a higher filling pressure, and can exhibit high water stop performance. In addition, since the contact surface in the axial direction can be easily increased by extending the axial length of the core tube and increasing the number of turns of the hose, a water stop plug with even higher water stop performance can be obtained, and there is an effect that it can be formed with a simple configuration because only one pressurized fluid inlet is required for the hose even if the number of turns is increased and the pressure contact area to the inner surface of the pipe is extended in the axial direction of the pipe.

[0009] In the present invention, the outer diameter D2 of the closing plate and the annular plate is formed smaller than the inner diameter D1 of the pipe to be sealed, and the hose spirally wound around the core tube is formed so as to expand when pressurized fluid is injected and press against the inner wall surface of the pipe. As a result, the difference between the inner diameter D1 of the pipe and the outer diameter D2 of the plate becomes the contractible width of the hose when the waterstop plug is attached to or detached from the pipe. Therefore, when the waterstop plug is inserted into or removed from the pipe without injecting pressurized fluid into the hose, the diameter can be made smaller by the above-mentioned contractible width, making it easy to perform the insertion and removal operations.

[0010] In the present invention, it is preferable that the outside of the spirally wound hose is covered with a cover body made of an elastic material so as to encase the hose in a cylindrical shape. This not only serves as a protective cover for the hose, but also increases the contact area with the inner wall of the pipe compared to when the hose is in contact with the periphery, thereby increasing the frictional force and improving the grip.The frictional force can be further increased and the gripping force improved by using an elastic material with a high coefficient of friction with the inner wall of the pipe for the cover body or by providing an uneven surface on the cover to increase the coefficient of friction with the inner wall of the pipe.

[0011] In the present invention, the closing plate may have an opening at its center to provide a connection port for connecting a bypass flow passage. This allows it to be used as a water stop plug with a bypass flow path. [Brief description of the drawings]

[0012] [Figure 1] 1 is an exploded perspective view showing one embodiment of a water stop plug according to the present invention. [Diagram 2] FIG. 4 is a cross-sectional view of the water stop plug shown in FIG. [Diagram 3] FIG. 4 is a cross-sectional view showing another embodiment of a water stop plug according to the present invention. BEST MODE FOR CARRYING OUT THEINVENTION

[0013] The water stop plug of the present invention will be described in detail below with reference to the embodiments. Figures 1 and 2 are an exploded perspective view and a cross-sectional view of a water stop plug of a type that completely blocks water flowing through a pipe according to one embodiment of the present invention.

[0014] The water stop plug A of this embodiment includes a cylindrical core tube 1 made of metal or hard resin, and a hose 2 spirally wound around the core tube 1. The hose 2 is formed of a double structure consisting of a watertight inner tube and an expansion tube made of circularly woven fiber material that covers the outer periphery of the inner tube, so that the hose can shrink and deform when no pressurized fluid is injected inside, and the outer fiber expansion tube makes the hose watertight with sufficient pressure resistance. Specifically, the inner tube is made of, for example, natural or synthetic rubber, polyvinyl chloride resin, polyurethane resin, etc., and the expansion tube is made of Vectran fiber or Izanas fiber.

[0015] One end of the hose 2 is provided with a pressurized fluid inlet 3, and the other end is closed with a sealing plug 4. The pressurized fluid inlet 3 of the hose 2 passes through a closing plate 5 so that its tip is exposed to the outside.

[0016] A circular closing plate 5 that closes one end face of the core tube 1 is fixed via a bolt, and an annular plate 6 is attached via a bolt to the other end face. The outer diameter D2 of the closing plate 5 and the annular plate 6 is formed to be larger than the outer diameter D3 of the core tube, and the spirally wound hose 2 is sandwiched between these plates.

[0017] In this embodiment, the outside of the spirally wound hose 2 is covered with a cylindrical cover body 7 made of a flexible material such as natural or synthetic rubber, soft resin, etc. Both end edge portions of the cover body 7 are bent inwardly and are sandwiched and held between the end face of the core tube 1 and each of the plates 5 and 6.

[0018] When pressurized fluid is injected into and expanded, the spirally wound hose 2 presses against the inner wall surface of the pipe B to be watertight via the cover body 7, and when the pressurized fluid is removed, it shrinks and deforms so that the waterstop plug A can be pulled out of the pipe B or loaded into the pipe B. Therefore, the outer diameter dimensions of each part of the attachable waterstop plug are set according to the inner diameter of the pipe B to be watertight. For example, if the inner diameter D1 of the pipe B to be waterproofed is 450 mm, the outer diameter D2 of the closing plate 5 and the annular plate 6 should be approximately 430 mm, the outer diameter D3 of the core tube 1 should be approximately 380 mm, and the outer diameter of the hose 2 wound around the core tube should be approximately 45 mm.

[0019] In the above case, the difference between the inner diameter D1 of the pipe B to be watertight and the outer diameter D2 of each plate of the watertight plug is the contractible width of the hose 2 including the cover body 7. As a result, when the watertight plug A is inserted into or pulled out of the pipe B without injecting pressurized fluid into the hose 2, it can be compressed by the contractible width, making it easy to insert or pull out. Also, by injecting pressurized fluid into the hose with the watertight plug A inserted into the pipe B, the hose 2 expands and presses against the inner wall of the pipe via the cover body 7, thereby stopping the water. At this time, the cover body 7 serves to increase the gripping force on the inner wall of the pipe in addition to serving as a protective cover for the hose.

[0020] The water stop plug constructed as above is used by inserting it into the pipe B, which is located upstream of the construction section of the pipe. A pipe 9 from a pressure fluid supply source 8 is connected to the pressure fluid inlet 3 of the inserted water stop plug A, and water as a pressure fluid is injected into the hose 2, expanding the hose 2 and pressing the inner wall surface of the pipe B through the cover body 7 to stop water. At this time, in the cross-sectional view of FIG. 2, the peripheral surface portion of the expanded circular cross-sectional hose 2 facing the inner wall of the pipe becomes a pressing point P, and the pressing points P are generated side by side along the pipe axis direction for the number of turns, i.e., eight turns in this embodiment. This allows the inner wall surface of the pipe to be pressed with a strong gripping force, and high water stop performance can be achieved. Furthermore, since each pressing point P is supported by the hose wall (expansion tube) with a circular cross section, high pressure resistance can be obtained. Furthermore, by extending the axial length of the core tube 1 and increasing the number of turns of the hose 2, a water-stopping plug with even higher water-stopping performance can be obtained, and even if the number of turns is increased and the pressure-contact area against the inner wall surface of the pipe is extended in the axial direction, only one pressurized fluid injection port 3 into the hose 2 is required, so the configuration can be simplified.

[0021] Although typical examples of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments. In the above embodiment, an example was shown in which the pipe B was applied to a type of water stop plug that completely stops water flow, but as shown in Fig. 3, it is also possible to form a bypass type water stop plug A' by penetrating the center of the closure plate 5 and providing a bypass flow path connection port 10 in this through hole. In this embodiment, water stop plugs A' are installed in both the upstream and downstream pipes B (only one is shown in the drawing) on ​​either side of the construction section, and bypass pipes 11 are connected to the connection ports 10 of each water stop plug to form a bypass flow path. This allows construction to be carried out without interrupting the flow of water in the pipes. In addition, the present invention can be modified or changed as appropriate without departing from the scope of the claims, while achieving its object. [Industrial Applicability]

[0022] INDUSTRIAL APPLICABILITY The present invention can be used as a water stop plug for temporarily stopping water flow in piping such as building water distribution pipes and water supply and sewerage pipes. [Explanation of symbols]

[0023] A Water stop plug B. Pipes to be water-stopped D1 Inner diameter of pipe D2 Outside diameter of closing plate and annular plate 1 core tube 2 Hose 3 Pressure fluid inlet 4 Sealing stopper 5 Closing Plate 6 Annular Plate 7 Cover body 10 Bypass flow connection port

Claims

1. A cylindrical core tube; an expandable hose spirally wound around an outer circumferential surface of the core tube; an annular plate attached to one end surface of the core tube; a closing plate attached to the other end surface of the core tube to close the other end surface, the hose is provided with a pressure fluid inlet at one end and a sealed end at the other end, and is disposed in a state sandwiched between the annular plate and the closing plate; The water stop plug is formed so that water is stopped by injecting pressurized fluid into the hose to expand it and press its circumferential surface against the inner wall surface of the pipe to be stopped.

2. 2. A water-stop plug as described in claim 1, wherein an outer diameter D2 of the closing plate and the annular plate is formed smaller than an inner diameter D1 of the pipe to be water-stopped, and a hose spirally wound around the core tube is expanded by injection of pressurized fluid to press against an inner wall surface of the pipe.

3. 2. The water stop plug according to claim 1, wherein the outer surface of the spirally wound hose is covered with a cover body made of an elastic material so as to encase the outer surface of the hose in a cylindrical shape.

4. 2. The water stop plug according to claim 1, wherein a connection port for connecting a bypass flow passage is formed by opening a central portion of the closing plate.

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