Flow path blocking device and flow path blocking method

Abstract

To provide: a flow passage closing device which can be made compact in a size of the device while preventing the damage of a closing bag; and a flow passage closing method.SOLUTION: A flow passage closing device comprises: a sealed case 20; shafts 30, 4A; a closing bag 4; a push-in operation mechanism 40; a shaft core adjustment member 50; and a protection sheet 22 which covers the closing bag 4 in a state that a part of the sheet is interposed between a tip face 50d of the shaft core adjustment member 50 and a base end region 4Ba of a bag main body 4B, and includes a holding part 22A for holding a state that the closing bag 4 is contracted in a size. When the closing bag 4 inserted into a fluid pipe 1 by the push-in operation mechanism 40 expands, the holding part 22A is released from a holding state, so that the protection sheet 22 is deformed following the expansion deformation of the closing bag 4.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a flow path closing device and a flow path closing method for closing a flow path in a fluid pipe. [Background technology]

[0002] A conventional flow path closing device has been disclosed that includes a branch pipe section that communicates with a perforated hole formed in a fluid pipe, and a blocking bag that is inserted into the in-pipe flow path of the fluid pipe via the perforated hole (see Patent Document 1). After the blocking bag is inserted into the in-pipe flow path, a diameter-expansion fluid is supplied into the blocking bag, causing the blocking bag to expand and deform in the diameter-expanding direction, thereby closing the in-pipe flow path.

[0003] The flow path blocking device described in Patent Document 1 comprises a sealed case that is detachably connected to a branch pipe section that communicates with a branch port and has a valve member, an insertion guide tube that is fitted into the sealed case, a shaft that is slidably installed through the sealed case and the insertion guide tube along the axis of the branch pipe section while maintaining a sealed state and has a flow path inside, a blocking bag that is fixed to the tip of the shaft located inside the insertion guide tube and can be expanded and deformed in the diameter-expanding direction by a diameter-expanding fluid supplied through the flow path, a pushing operation means that pushes and moves the shaft against the fluid pressure in the fluid pipe, and an axis adjustment member that is fixed to the tip of the shaft located inside the insertion guide tube and can slide against the inner surface of the insertion guide tube. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-55287 Summary of the Invention [Problem to be solved by the invention]

[0005] However, because the occlusion bag is inserted into the internal flow path of the fluid pipe through the perforation opening, there is a risk that the occlusion bag may come into contact with or get caught on burrs that occur on the inner surface of the perforation opening or protrusions that exist on the inner surface of the branch pipe section during insertion, and be damaged or broken.To prevent damage to the occlusion bag, the flow path occlusion device described in Patent Document 1 is provided with an insertion guide tube that is fitted inside the sealed case, and the insertion guide tube is moved to the perforation opening with the occlusion bag housed inside the insertion guide tube.

[0006] However, when recovering the occlusion bag described in Patent Document 1, once inflated, the occlusion bag does not return to a cylindrical shape that can be accommodated inside the insertion guide tube even when it is deflated, so it was necessary to secure a space inside the sealed case to accommodate the occlusion bag and the insertion guide tube. As a result, the axial dimension of the sealed case had to be increased, which could make it difficult to install the flow path occlusion device depending on the on-site conditions.

[0007] Therefore, there is a demand for a flow path closing device and a flow path closing method that can prevent damage to the closing bag while making the device more compact. [Means for solving the problem]

[0008] A characteristic configuration of a flow path closing device according to the present invention is a flow path closing device including a closing bag that is inserted into a fluid pipe through a perforated opening formed in the fluid pipe and expands and deforms in the diameter-expanding direction to close a flow path within the fluid pipe, the flow path closing device comprising: a sealed case that is detachably connected to a branch pipe section that communicates with the perforated opening and has a valve member; a shaft that penetrates the inside of the sealed case along the axis of the branch pipe section while maintaining a sealed state and includes a flow path therein; and a shaft that has a reduced shape that can be housed in the sealed case while fixed to the tip of the shaft, and that automatically expands and deforms in the diameter-expanding direction by a diameter-expanding fluid supplied through the flow path. the occlusion bag, a pushing mechanism that pushes in and moves the shaft against the fluid pressure in the fluid pipe; a cylindrical axis alignment member that is inserted onto the shaft and has a tip surface that faces the base end portion of the occlusion bag; and a protective sheet that covers the occlusion bag with a portion of the protective sheet being sandwiched between the tip surface and the base end portion and includes a retaining portion that maintains the occlusion bag in a contracted state, wherein when the occlusion bag inserted into the fluid pipe by the pushing mechanism expands, the retaining portion releases the retaining state of the protective sheet and the protective sheet deforms in accordance with the expansion and deformation of the occlusion bag.

[0009] According to this configuration, the internal flow path of the fluid pipe and the inside of the branch pipe section can be maintained in a sealed state by the sealed case connected to the branch pipe section and the shaft inserted through the sealed case, and the internal flow path of the fluid pipe can be closed by the blocking bag fixed to the tip of the shaft while maintaining an uninterrupted flow of fluid in the internal flow path of the fluid pipe.

[0010] The flow path closing device of this configuration also includes a protective sheet that covers the closing bag with a portion of the protective sheet being sandwiched between the distal end surface of the axis alignment member and the proximal end portion of the closing bag, and the protective sheet includes a retaining portion that maintains the closing bag in a contracted state. Therefore, the retaining portion maintains the contracted state of the closing bag inside the sealed case, and the protective sheet prevents the closing bag from coming into contact with burrs on the inner surface of the perforation opening or protrusions on the inner surface of the branch pipe portion and being damaged.

[0011] When the occlusion bag inserted into the fluid pipe by the pushing mechanism expands, the protective sheet is released from the holding state of the holding part and deforms in response to the expansion and deformation of the occlusion bag, thereby achieving the desired flow path occlusion function without impeding the expansion and deformation of the occlusion bag.In addition, because a portion of the protective sheet is sandwiched between the distal end surface of the axis alignment member and the proximal end portion of the occlusion bag, there is no problem with the protective sheet falling into the flow path within the pipe.

[0012] This makes it possible to omit the conventional insertion guide tube, and since it is sufficient to ensure only the accommodation space for the inflatable bag in the sealed case, the axial dimension of the sealed case can be reduced.

[0013] In this way, even when the fluid pressure of the fluid flowing through the intra-pipe flow path acts on the occlusion bag in an uninterrupted flow state, the protective sheet prevents the occlusion bag from contacting the inner surface of the sealed case or the inner surface of the branch pipe, and allows the occlusion bag to move within the sealed case and the branch pipe along the axis of the branch pipe. When the occlusion bag is positioned in the intra-pipe flow path blocking position, a portion of the protective sheet is sandwiched between the distal end surface of the axis adjustment member and the proximal end of the occlusion bag, and is located at a position radially corresponding to the perforation opening. Therefore, even if the occlusion bag is pressed downstream by the fluid pressure of the fluid flowing through the intra-pipe flow path in an uninterrupted flow state, the occlusion bag will not come into contact with burrs or the like on the inner surface of the perforation opening, and damage will be prevented.

[0014] Therefore, it is possible to obtain a flow path closing device that can be made compact while preventing damage to the closing bag.

[0015] Another characteristic feature is that the holding portion is composed of a string that ties the divided protective sheet together, and when the occlusion bag is inflated, the string is untied and the holding state is released.

[0016] If the holding portion is made of a string as in this configuration, the number of places where the string is tied can be increased or decreased depending on the size of the inflation bag, which allows for greater design freedom and reduces manufacturing costs.

[0017] Another characteristic feature is that the retaining portion is composed of a connecting tape that connects the divided surfaces of the protective sheet, and when the occlusion bag is inflated, the connecting tape comes loose and the retaining state is released.

[0018] As in this configuration, if the holding portion is formed of a joining tape that joins the divided surfaces of the protective sheet, the efficiency of attaching the protective sheet to the closure bag can be improved.

[0021] a sealing case having a connecting flange connected to a flange of a branch pipe section having a valve member, the connecting flange being connected to the flange; a movable cylinder movable along the axis of the branch pipe section relative to the connecting flange; a shaft extending through the sealing case along the axis while maintaining a sealed state and including a flow path; the sealing bag having a contracted shape that can be accommodated in the movable cylinder while fixed to the tip of the shaft, the sealing bag being expandable and deformable in the diameter-expanding direction by a diameter-expanding fluid supplied through the flow path; and a pushing mechanism for pushing the shaft and the movable cylinder against the fluid pressure in the fluid pipe;

[0022] According to this configuration, the internal flow path of the fluid pipe and the inside of the branch pipe section can be maintained in a sealed state by the sealed case connected to the branch pipe section and the shaft inserted through the sealed case, and the internal flow path of the fluid pipe can be closed by the blocking bag fixed to the tip of the shaft while maintaining an uninterrupted flow of fluid in the internal flow path of the fluid pipe.

[0023] The flow path closing device of this configuration also includes a sealed case having a movable cylinder that is movable relative to the connecting flange along the axis of the branch pipe, and a closure bag is housed inside the movable cylinder in a contracted state. The pushing mechanism then moves the tip of the movable cylinder to the drilling opening. This keeps the closure bag in a contracted state inside the movable cylinder, and the movable cylinder prevents the closure bag from coming into contact with burrs on the inner surface of the drilling opening or protrusions on the inner surface of the branch pipe and causing damage.

[0024] Furthermore, the pushing operation mechanism moves the tip of the movable cylinder to the drilling hole, then moves the shaft relative to the movable cylinder to insert the occlusion bag into the fluid pipe, so that the desired flow path occlusion function is achieved without the movable cylinder hindering the expansion and deformation of the occlusion bag.

[0025] This makes it possible to omit the conventional insertion guide tube, and since it is sufficient to ensure only the accommodation space for the inflation bag in the sealed case (movable tube), the axial dimension of the sealed case can be reduced.

[0026] In this way, even when the fluid pressure of the fluid flowing through the intra-pipe flow path acts on the occlusion bag in an uninterrupted flow state, the movable cylinder allows the occlusion bag to move within the branch pipe along the axis of the branch pipe without contacting the inner surface of the branch pipe. When the occlusion bag is positioned in the intra-pipe flow path blocking position, the tip of the movable cylinder is located at a position radially corresponding to the perforation opening of the fluid pipe. Therefore, even if the occlusion bag is pressed downstream by the fluid pressure of the fluid flowing through the intra-pipe flow path in an uninterrupted flow state, the base end of the occlusion bag is protected by the tip of the movable cylinder and is prevented from being damaged.

[0027] Therefore, it is possible to obtain a flow path closing device that can be made compact while preventing damage to the closing bag.

[0028] Another characteristic feature is that a protrusion is formed on the outer surface of the movable cylinder, which abuts against the underside of the connecting flange portion when subjected to fluid pressure in the fluid pipe, thereby preventing the movable cylinder from slipping out.

[0029] By providing a protrusion on the movable cylinder as in this configuration, it is possible to prevent the movable cylinder from coming off the connecting flange even when the fluid pressure of the fluid flowing through the pipe flow path acts on the occlusion bag in an uninterrupted flow state, and as a result, the occlusion bag can be reliably held inside the movable cylinder with its posture stabilized.

[0030] The flow path blocking method according to the present invention is characterized by the following features: As mentioned above A flow path closing method using a flow path closing device, record The method includes a drilling step in which the drilling opening is formed in the fluid pipe using a cutter of a drilling device connected to the branch pipe section; a burr removal step in which a cutting device is connected to the branch pipe section in place of the drilling device and the cutting bit of the cutting device is rotated while being held in contact with the inner peripheral edge of the drilling opening to remove burrs on the inner peripheral edge; and a closing step in which the flow path closing device is connected to the branch pipe section in place of the cutting device, the closing bag is inserted into the fluid pipe through the drilling opening, and then the closing bag is inflated to close the flow path within the pipe.

[0031] According to this method, the blocking process allows the flow of fluid through the fluid pipe's internal flow path to be maintained without interruption by inserting a blocking bag into the fluid pipe through the perforation, and then inflating the blocking bag to close the internal flow path.

[0032] Furthermore, the flow path closing device of this configuration includes a burr removal step between the drilling step and the closing step, in which burrs on the inner peripheral edge of the drilling opening are removed while the cutting tool of the cutting device is rotated in contact with the inner peripheral edge of the drilling opening. Therefore, the blocking bag inserted into the fluid pipe through the drilling opening after the burrs have been removed is prevented from being damaged even if it comes into contact with the inner surface of the drilling opening.

[0033] This makes it possible to omit the conventional insertion guide tube, and since it is sufficient to ensure only the accommodation space for the inflation bag in the flow path closing device, the axial dimension of the flow path closing device can be reduced.

[0034] In this way, even if the blocking bag is pressed to move downstream by the fluid pressure from the fluid flowing through the pipe flow path in an uninterrupted flow state, the blocking bag comes into contact with the drilled hole from which the burrs have been removed, thereby preventing damage.

[0035] Therefore, a flow path blocking method can be obtained that can prevent damage to the blocking bag while making the device more compact. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 10 is a longitudinal cross-sectional view showing a fluid piping system connected to a branch pipe section that communicates with a drilled hole. [Figure 2] 1 is a longitudinal cross-sectional view showing a state in which a flow path closing device according to a first embodiment is attached to a branch pipe portion. FIG. [Figure 3] FIG. 10 is a schematic diagram showing the contracted state of the occlusion bag. [Figure 4] FIG. 3 is a longitudinal cross-sectional view showing a state in which a shaft is pushed in using the flow path closing device of the first embodiment. [Figure 5] 1 is a longitudinal cross-sectional view showing a state in which a blocking bag is inserted into a pipe flow path using the flow path blocking device of the first embodiment. FIG. [Figure 6] 1 is a longitudinal cross-sectional view showing a state in which a blocking bag located at a position for blocking a flow path in a pipe is inflated and deformed using the flow path blocking device of the first embodiment. FIG. [Figure 7] 10A to 10C are longitudinal cross-sectional views showing a process of storing a blocking bag in a sealed case from a position blocking a flow path in a pipe using the flow path blocking device of the first embodiment. [Figure 8] FIG. 4 is a vertical cross-sectional view showing a state in which the flow path closing device of the first embodiment is being removed from a branch pipe portion. [Figure 9] FIG. 2 is a schematic diagram showing a protective sheet attachment jig. [Figure 10] FIG. 10 is a vertical cross-sectional view showing a state in which an occlusion bag is inserted into an intra-pipe flow path, as a first modified example of the first embodiment. [Figure 11] FIG. 10 is a longitudinal sectional view showing a state in which a blocking bag located at a pipe flow path blocking position is inflated and deformed, as a first modified example of the first embodiment. [Figure 12] FIG. 10 is a vertical cross-sectional view showing a state in which a shaft is being pushed in as a second modified example of the first embodiment. [Figure 13] FIG. 10 is a longitudinal cross-sectional view showing a state in which an occlusion bag is inserted into an intra-pipe flow path, as a second modified example of the first embodiment. [Figure 14] FIG. 10 is a longitudinal cross-sectional view showing a state in which a blocking bag located at a pipe flow path blocking position is inflated and deformed, as a second modified example of the first embodiment. [Figure 15] FIG. 10 is a longitudinal cross-sectional view showing a state in which a flow path closing device according to a second embodiment is connected to a branch pipe portion. [Figure 16] FIG. 10 is a vertical cross-sectional view showing a state in which a movable cylinder is pushed in using a flow path closing device of a second embodiment. [Figure 17] FIG. 10 is a longitudinal cross-sectional view showing a state in which a blocking bag is inserted into a pipe flow path using a flow path blocking device of a second embodiment. [Figure 18] FIG. 10 is a longitudinal cross-sectional view showing a state in which a blocking bag located at a position for blocking a flow path in a pipe is inflated and deformed using a flow path blocking device of a second embodiment. [Figure 19] FIG. 10 is a vertical cross-sectional view showing a burr removing step in the flow path closing method. [Figure 20] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, an embodiment of a flow path closing device and a flow path closing method according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0038] FIG. 2 shows a flow-stopping type flow-path closing device A equipped with a blocking bag 4 that is inserted into a cast iron water pipe 1 (an example of a fluid pipe) constituting part of a fluid piping system through a perforation 2 formed in the water pipe 1 and expands and deforms to close an in-pipe flow path 3 of the water pipe 1. FIGS. 1 to 8 show a flow-path closing method using this flow-path closing device A to close the in-pipe flow path 3 while maintaining an uninterrupted water supply (uninterrupted flow state) by maintaining the flow of clean water Q (an example of a fluid) flowing through the water pipe 1. Note that this flow-path closing method using the flow-path closing device A is carried out to perform renewal or repair work on water pipes 1 or fire hydrants (not shown) that have reached the end of their useful life or are due for renewal due to leakage or breakdown caused by deterioration, while maintaining an uninterrupted water supply, at a location downstream of the location in the in-pipe flow path 3 where the blocking bag 4 has been closed.

[0039] When installing the flow path blocking device A according to this embodiment, first, as shown in Figure 1, a split T-shaped pipe 5 having a split structure is installed in a water pipe 1 in a watertight state in a predetermined area (an area including the planned location for drilling a drilling hole 2) upstream of the location where work such as updating a fire hydrant will be performed, and a branch pipe section connecting step is carried out to watertightly connect a gate valve 7 (an example of a valve member) to a valve mounting hole 6 of this split T-shaped pipe 5. Note that although a drilling hole 2 is formed in the water pipe 1 in Figure 1, at the stage of the branch pipe section connecting step, the drilling hole 2 has not yet been formed and the gate valve 7 is in an open state.

[0040] The split T-shaped pipe 5 is composed of partially cylindrical split coupling bodies 5A divided into three circumferentially, radially and flexibly mounted on the water pipe 1. Each split coupling body 5A has a flange 5a integrally formed at both circumferential ends thereof for detachably fastening adjacent ends of the split coupling bodies 5A mounted on the water pipe 1 via a plurality of bolts 8 and nuts 9. A synthetic rubber sealant 5c is fitted into a seal retaining groove 5b formed on the inner surface of each split coupling body 5A to provide a watertight seal between the split coupling body 5A and the outer surface 1a of the water pipe 1. A cylindrical valve mounting port 6 having an inner diameter larger than the diameter of the drilling port 2 is integrally formed in the center of each split coupling body 5A, protruding radially outward from the water pipe 1. The split T-shaped pipe 5 is not limited to being divided into three parts, but may be divided into two or more parts, and the fastening method is not limited to being bolted, but may also be welding or the like.

[0041] The valve mounting port 6 comprises a pipe section 6a that communicates with the drilled port 2 of the water pipe 1 and has an inner diameter larger than the diameter of the drilled port 2, an annular flange section 6b formed at the downstream end of the pipe section 6a, and an annular recessed groove 6c formed at the inner diameter side portion of the annular flange section 6b and capable of engaging with the upstream end of the tubular section 7a of the gate valve 7. An annular flange section 7A that protrudes and is formed at the longitudinal middle portion of the tubular section 7a of the gate valve 7 is fastened and fixed to the annular flange section 6b of the valve mounting port 6 with bolts 10 and nuts 11 in a detachable manner.

[0042] The check valve 7 comprises a tubular portion 7a formed with a diameter larger than the inner diameter of the perforation opening 2 and approximately the same diameter as the pipe portion 6a of the valve mounting port portion 6, an upstream annular flange portion 7A formed in the longitudinal middle portion of the tubular portion 7a and removably connected to the annular flange portion 6b of the pipe portion 6a by bolts 10 and nuts 11 in a watertight state with the upstream end of the tubular portion 7a engaged with the annular groove 6c of the valve mounting port portion 6 via an O-ring (not shown), a downstream annular flange portion 7B removably connected in a watertight state to the connecting flange portion 20A of the sealed case 20 of the flow path blocking device A described later via bolts 12 and nuts 13, and a valve body 7C that can block the flow path of the tubular portion 7a between the annular flange portion 7A and the annular flange portion 7B. In other words, the valve mounting port portion 6 and the gate valve 7 in the split coupling body 5A function as the branch pipe portion B, and a flow path is formed within the branch pipe portion B that communicates with the outer surface of the water pipe 1 (the location where the drilling port 2 is planned to be drilled) along the axis Y. The shape of the gate valve V is not particularly limited, and as long as it has an annular flange portion 7A, annular flange portion 7B, and a valve body 7C, it may have a compact shape with an even smaller dimension in the direction of the axis Y.

[0043] Next, although this is a well-known configuration and is not shown in the drawings for simplicity of explanation, a drilling step is carried out in which a drilling device is connected to the annular flange portion 7B downstream of the gate valve 7, and a hole saw (an example of a cutter) of the drilling device is used to drill a circular drilling opening 2 in the pipe wall of the water pipe 1. This drilling device comprises a cylindrical casing with a bottom that has a flange that can be connected in a watertight manner to the annular flange portion 7B downstream of the gate valve 7 via bolts and nuts, and a hole saw that is installed through the bottom of the casing and is movable within the casing in the longitudinal direction of the casing and can be driven to rotate. In the drilling process, the flange portion of the casing is watertightly connected to the annular flange portion 7B of the gate valve 7, whose valve element 7C is in the closed state, via bolts and nuts, and the hole saw of the drilling device is fed along the axis Y of the branch pipe portion B through the cylindrical portion 7a of the gate valve 7, the valve element 7C that has been opened, and the pipe portion 6a of the valve mounting port portion 6 to drill and form a circular drilling hole 2 in the pipe wall of the water pipe 1. After the drilling hole 2 is formed, the hole saw and the circular cut piece are placed inside the casing, and the valve element 7C is closed to release the connection between the flange portion of the casing and the annular flange portion 7B of the gate valve 7, and the drilling device is removed from the gate valve 7.

[0044] First Embodiment 2 to 8, the closing step of connecting the flow path closing device A according to the first embodiment to the gate valve 7 in a watertight state after the drilling step to close the in-pipe flow path 3 will be described.

[0045] As shown in FIG. 2, the flow path closing device A includes a sealed case 20 detachably connected to a branch pipe section B that is connected to the perforation opening 2 and has a gate valve 7; a cylindrical shaft 30 (an example of a shaft) that is slidably inserted along the axis Y of the branch pipe section B while maintaining a sealed state and has a flow path 30A inside; a nozzle member 4A (an example of a shaft) that has a fitting cylindrical section 4a that is fitted into the tip 30B of the cylindrical shaft 30; a closing bag 4 that is fixed to the tip 30E of the shaft made up of the cylindrical shaft 30 and the nozzle member 4A and can be expanded and deformed in the diameter-expanding direction by a diameter-expanding fluid P supplied through the flow path 30A; a pushing operation mechanism 40 that pushes and moves the cylindrical shaft 30 against the fluid pressure in the water pipe 1; and a cylindrical axis adjustment member 50 that is fitted onto the cylindrical shaft 30 and the nozzle member 4A and has a tip surface 50d that faces the base end portion 4Ba of the closing bag 4.

[0046] The sealed case 20 is formed in a bottomed cylindrical shape, with a cylindrical wall 20a formed with an inner diameter substantially the same as the inner diameter of the cylindrical portion 7a of the gate valve 7, and a bottom wall portion 20b closing the downstream end of the cylindrical wall 20a, and has an internal space 21 long enough to accommodate a contracted occlusion bag 4. The upstream end of the cylindrical wall 20a is formed with a connecting flange portion 20A that is detachably and watertightly connected to the downstream annular flange portion 7B of the gate valve 7 via bolts 12 and nuts 13, and a cylindrical shaft 30 is slidably inserted through the bottom wall portion 20b while maintaining a sealed state with an annular seal member 20c. In addition, eye nuts 20e with annular locking portions 20d are fixed to the outer peripheral surface of the cylindrical wall 20a at positions near the bottom wall portion 20b and facing each other across the cylindrical shaft 30, using bolts or the like fixed to the outer peripheral surface of the cylindrical wall 20a.

[0047] The cylindrical shaft 30 is formed in a cylindrical shape and has a communication passage 30A therein. The cylindrical shaft 30 is slidably inserted through the bottom wall 20b of the sealed case 20 along the axis Y of the branch pipe B while maintaining a sealed state. A distal end 30B of the cylindrical shaft 30 is configured so that the fitting cylindrical portion 4a of the mouthpiece member 4A provided at the base end portion 4Ba of the occlusion bag 4 can be fitted therein, and a pair of threading holes 30b into which set screws 30a can be threaded are formed through the distal end 30B of the cylindrical shaft 30 in the radial direction of the cylindrical shaft 30. With the fitting cylindrical portion 4a fitted therein, the set screws 30a can be threaded into the threading holes 30b until the distal end of the set screws 30a abuts against and locks onto the locking steps 4b formed on the fitting cylindrical portion 4a, thereby connecting the occlusion bag 4 to the cylindrical shaft 30 in a watertight state.

[0048] The rear end 30C of the cylindrical shaft 30 closes the flow path 30A and is configured as a pulley arrangement member having a pulley 30c rotatably supported around a rotation axis (not shown), and is configured so that a chain 41 (or a wire, etc.) of a pushing operation mechanism 40 (described later) can be stretched across the pair of annular locking portions 20d of the sealed case 20 via the pulley 30c. On the upstream side of the rear end 30C of the cylindrical shaft 30, there are provided a supply path 31 that supplies a diameter-expansion fluid P from a supply source (not shown) external to the cylindrical shaft 30 via a supply valve 31a to the flow path 30A, and a discharge path 32 that discharges the diameter-expansion fluid P from the flow path 30A via a discharge valve 32a.

[0049] Furthermore, a pair of insertion position restricting protrusions 30D are formed on the outer peripheral surface of the cylindrical shaft 30 at positions facing each other across the cylindrical shaft 30, protruding radially outward from the cylindrical shaft 30. These insertion position restricting protrusions 30D are configured to come into contact with the outer surface (outer surface of the bottom) of the bottom wall 20b of the sealed case 20 when the cylindrical shaft 30 slides along the axis Y of the branch pipe B, and restrict the insertion state of the cylindrical shaft 30 to the maximum insertion position (restrict the insertion state of the blocking bag 4 into the water pipe 1 so that it becomes the in-pipe flow path blocking position).

[0050] As shown in FIG. 3 , the occlusion bag 4 is fixed to the cylindrical shaft 30 and the distal end 30E of the mouthpiece 4A located within the sealed case 20, and is configured to be expandable and deformable in the diameter-expanding direction by a diameter-expansion fluid P supplied through the passage 30A. The diameter-expansion fluid P can be a gas such as compressed air or a liquid such as water, as long as it can expand and deform the occlusion bag 4 and close the in-pipe passage 3 when supplied into the occlusion bag 4. The occlusion bag 4 includes a bag body 4B that can be expanded and deformed in the diameter-expansion direction by the diameter-expansion fluid P. The passage closing device A further includes a protective sheet 22 that covers the occlusion bag 4, with a portion (proximal end side) sandwiched between the distal end surface 50d of the axis alignment member 50 and the proximal end portion 4Ba of the bag body 4B. The mouthpiece 4A has a fluid supply / discharge passage 4c that can supply or discharge the diameter-expansion fluid P into or from the bag body 4B via the passage 30A.

[0051] The bag body 4B is formed in a bag shape and has a double structure with an inner bag (not shown) made of rubber such as natural rubber or synthetic rubber, and an outer bag (not shown) made of a fibrous material such as cloth, rubber, or a flexible material in which these are integrated in layers. Note that instead of a double structure, a single structure or a triple or more layer structure may also be used.

[0052] As shown in FIG. 2 , the protective sheet 22 includes a retaining portion 22A that maintains the occlusion bag 4 in a contracted state, and the retaining portion 22A maintains the occlusion bag 4 in a generally cylindrical shape that can be accommodated in the sealed case 20. The protective sheet 22 is made of a resin material such as vinyl or a fibrous material such as cloth, and is divided so that both circumferential ends overlap each other. In this embodiment, the retaining portion 22A is composed of multiple strings 22Aa that tie the divided protective sheet 22 together. Each string 22Aa is inserted into multiple slits 22a provided in the protective sheet 22 and wound around the occlusion bag 4 in the circumferential direction. A knot 22Aa1 is provided at each end of the string 22Aa, and a binding portion 22Aa2 is provided by tying each end of the string 22Aa closer to the slit 22a than the knot 22Aa1. If the holding portion 22A is made of a string 22Aa as in this embodiment, the number of places where the string 22Aa is tied can be increased or decreased depending on the dimensions of the occlusion bag 4, which allows for greater design freedom and reduces manufacturing costs.

[0053] The binding portion 22Aa2 is formed by a slip knot, a vertical knot, or the like, so that the tightening force increases when both ends are pulled so that the occlusion bag 4 contracts, and can be untied as both ends become free ends when the occlusion bag 4 is inflated. With this configuration, by providing strings 22Aa that bind the divided protective sheet 22 with the binding portions 22Aa2, when the occlusion bag 4 inflates, the strings 22Aa (binding portions 22Aa2) are untied, the holding state of the holding portions 22A is released, and the protective sheet 22 deforms in response to the expansion and deformation of the occlusion bag 4. At this time, the knotted portion 22Aa1 cannot enter the slits 22a, so the strings 22Aa are prevented from coming off the protective sheet 22.

[0054] The nozzle member 4A is configured to include a fitting tubular portion 4a having a fluid supply / discharge passage 4c therein, one end of which is fitted onto the tip 30B of the tubular shaft 30 and the other end of which passes through the bag body 4B and is positioned within the bag body 4B, a cylindrical bag internal threaded member 4e which is positioned within the bag body 4B and threaded into a female thread (not shown) formed on the outer surface of the other end of the fitting tubular portion 4a, a cylindrical bag external mounting member 4f which fits into one end of the fitting tubular portion 4a located outside the bag body 4B and clamps a part of the bag body 4B between it and the bag internal threaded member 4e, and a fixing nut 4g which threads into a female threaded portion (not shown) formed on the outer surface of one end of the fitting tubular portion 4a located outside the bag body 4B and tightens and fixes the bag external mounting member 4f to the bag internal threaded member 4e side.

[0055] The longitudinal direction of the fitting tubular portion 4a is arranged so as to follow the longitudinal direction of the tubular axis 30 (the direction of the axis Y of the branch pipe portion B), and when the diameter-expansion fluid P is not being supplied into the bag body 4B, the bag body 4B is configured so as to be able to be folded in a state where it has contracted into a rod shape with the other end of the fitting tubular portion 4a penetrating into the bag body 4B at the center. When the bag body 4B is folded in a state where it has contracted into a rod shape and the contracted shape is maintained by the retaining portion 22A of the protective sheet 22, the outer diameter of the bag body 4B is slightly smaller than the inner diameter of the sealed case 20, and it is configured so as to be able to be housed in the sealed case 20 (see FIG. 2).

[0056] On the other hand, when the diameter-expansion fluid P is supplied to the inside of the bag body 4B, the bag body 4B is configured to expand and deform in the diameter-expansion side into a bag-like, approximately cylindrical shape (see FIG. 6), and has an outer diameter that allows the outer peripheral surface to closely contact the inner peripheral surface of the in-pipe flow path 3. That is, when the bag body 4B expands and deforms into a approximately cylindrical shape, the bag body 4B expands and deforms so that the diameter of the cylinder increases in the longitudinal direction of the fitting cylindrical portion 4a (the longitudinal direction of the cylindrical axis 30) and the height of the cylinder increases in the direction perpendicular to the longitudinal direction of the fitting cylindrical portion 4a. On the outer peripheral surface of the bag body 4B (occlusion bag 4), annular seal portions 4i are protruded at positions on both sides of the fitting cylindrical portion 4a (the cylindrical axis 30) in the direction perpendicular to the longitudinal direction of the fitting cylindrical portion 4a, and the annular seal portions 4i are pressed against the inner peripheral surface of the water pipe 1 over the entire circumferential direction when the occlusion bag 4 expands and deforms.

[0057] 2, a locking step 4b is formed on the outer surface of one end of the fitting tubular portion 4a, recessed from the outer surface toward the inner diameter at a position corresponding to a threaded hole 30b formed through the tip 30B when one end of the fitting tubular portion 4a is fitted onto the tip 30B of the tubular shaft 30. A pair of O-rings 4h are disposed on the outer surface further toward the end side than the locking step 4b, maintaining a watertight state between the tip 30B of the tubular shaft 30 and the inner surface of the communication passage 30A. The outer diameter of the bag external mounting member 4f is formed slightly smaller than the inner diameter of the axis alignment member 50 so that the bag external mounting member 4f can be fitted into the axis alignment member 50 (described later). The outer surface of the bag external mounting member 4f is configured to be in sliding contact with the inner surface 50a of the axis alignment member 50.

[0058] The pushing operation mechanism 40 is configured to push and move the tubular shaft 30 against the fluid pressure inside the water pipe 1, and includes a pair of hook members 42 that can be engaged with a pair of annular locking portions 20d provided on the sealed case 20, a chain 41 (or wire, etc.) that is stretched across the pair of annular locking portions 20d by the hook members 42 via a pulley 30c disposed on the rear end portion 30C of the tubular shaft 30, and an operation lever 43 that operates to wind up the chain 41 to the tightening side. The operation lever 43 is configured from a lever block (registered trademark) that not only operates to wind up the chain 41 to the tightening side, but also can hold the chain 41 in a tightened position and operate to the release side to release the tightening.

[0059] 3, the axis alignment member 50 is fixed to the tip 30B of the cylindrical shaft 30, and is fitted onto the cylindrical shaft 30 in a state in which the outer surface of the axis alignment member 50 can slide against the inner surface of the sealed case 20. Specifically, the axis alignment member 50 is formed in a bottomed cylindrical shape including a cylindrical wall portion 50b formed with an outer diameter smaller than the inner diameter of the sealed case 20 and an inner diameter slightly larger than the outer diameter of the bag outer mounting member 4f, and a bottom wall portion 50c through which the tip 30B of the cylindrical shaft 30 passes.

[0060] A pair of threaded holes 52 into which set screws 51 can be threaded are formed through the bottom wall portion 50c in the radial direction of the axis alignment member 50 (radial direction of the cylindrical shaft 30). As a result, the axis alignment member 50 can be fixed to the tip 30B of the cylindrical shaft 30 by threading the set screws 51 into the threaded holes 52 until the tip ends of the set screws 51 abut and lock onto the outer circumferential surface of the tip 30B of the cylindrical shaft 30. In this manner, when the axis alignment member 50 is fixed to the tip 30B of the cylindrical shaft 30, at least a portion of the inner surface 50a of the cylindrical wall portion 50b of the axis alignment member 50 is positioned close to the radially outward side of the outer surface of the bag outer mounting member 4f of the mouthpiece member 4A.

[0061] The connecting flange portion 20A of the sealed case 20 of the flow path closing device A configured in this manner is connected in a watertight manner to the annular flange portion 7B downstream of the gate valve 7 via bolts 12 and nuts 13. In this state, the internal space 21 of the sealed case 20 contains the closing bag 4, which is covered with a protective sheet 22 and maintained in its contracted shape by the holding portion 22A.

[0062] Next, as shown in Figure 4, the valve body 7C is opened, and the chain 41 is wound up to the tightening side using the operating lever 43 of the pushing operation mechanism 40, and the cylindrical shaft 30 is pushed along the axis Y of the branch pipe section B toward the internal flow path 3 through the cylindrical section 7a of the check valve 7, the valve body 7C, and the pipe section 6a of the valve mounting port section 6 against the fluid pressure of the clean water Q flowing through the internal flow path 3.

[0063] When the cylindrical shaft 30 is moved along the axis Y of the branch pipe section B in this manner, as shown in Fig. 4, the cylindrical shaft 30 moves relative to the sealed case 20, and the protective sheet 22 approaches the outer peripheral edge 2a of the drilled opening 2. As a result, even when the fluid pressure of the clean water Q flowing through the in-pipe flow path 3 acts on the occlusion bag 4 in an uninterrupted flow state, the outer surface of the occlusion bag 4 is protected by the protective sheet 22, so the occlusion bag 4 itself can be moved within the sealed case 20 and the branch pipe section B along the axis Y of the branch pipe section B without coming into contact with the inner surface of the sealed case 20 or the inner surface of the branch pipe section B. Furthermore, even if the cylindrical shaft 30 is misaligned with the axis Y of the branch pipe section B, the axis adjustment member 50 functions as a guide member when inserting the occlusion bag 4 into the drilled opening 2, and the cylindrical shaft 30, which is inserted through the sealed case 20, can be positioned approximately coaxially with the axis Y of the branch pipe section B. Furthermore, since the protective sheet 22 comes into contact with the perforation opening 2, the protective sheet 22 covers the inner surface of the perforation opening 2 (the inner surface of the perforation opening 2 in the direction along the pipe axis X of the water pipe 1), and when the blocking bag 4 is moved through the perforation opening 2 to the in-pipe flow path 3 of the water pipe 1, the blocking bag 4 does not come into contact with burrs on the inner surface of the perforation opening 2 or protrusions on the inner surface of the branch pipe section B, thereby further preventing damage to the blocking bag 4.

[0064] Thereafter, the chain 41 is further wound up to the tightening side using the operating lever 43 of the pushing operation mechanism 40, and the tubular shaft 30 is pushed along the axis Y of the branch pipe section B against the fluid pressure of the clean water Q flowing through the in-pipe flow path 3. When the tubular shaft 30 is further moved along the axis Y of the branch pipe section B toward the in-pipe flow path 3 in this manner, as shown in Fig. 5, the occlusion bag 4 fixed to the tip 30E of the shaft formed by the tubular shaft 30 and the nozzle member 4A moves along the axis Y of the branch pipe section B toward the in-pipe flow path 3. In this state, the bag body 4B abuts against the lower surface of the water pipe 1, and the lower portion naturally expands, and a part (lower side) of the binding portion 22Aa2 of the holding portion 22A is loosened, and the holding state of the holding portion 22A (string 22Aa) is partially released. As a result, the protective sheet 22 deforms in accordance with the natural deformation of the lower portion of the bag body 4B, and both circumferential ends thereof become flared as if torn apart.

[0065] As shown in Figure 5, when the insertion position restricting protrusion 30D formed on the outer surface of the cylindrical shaft 30 abuts against the bottom wall portion 20b of the sealed case 20, the blocking bag 4 is located at the intended intra-pipe flow path blocking position in the intra-pipe flow path 3, the axis center adjustment member 50 is located at a position corresponding to the perforation opening 2 in the radial direction of the water pipe 1, and the tip surface 50d of the axis center adjustment member 50 and the radially inner end of the water pipe 1 at the perforation opening 2 are located at the same position in the radial direction of the water pipe 1.

[0066] Next, the supply valve 31a is opened to supply a predetermined amount of diameter-expansion fluid P into the bag body 4B of the blocking bag 4 located at the intra-pipe flow path blocking position through the supply path 31, the flow path 30A, and the fluid supply / discharge path 4c, causing the bag body 4B to expand in the direction of the pipe axis X of the water pipe 1 and radially outward (see also FIG. 2). Then, as shown in FIG. 6, when the bag body 4B expands and deforms to become a roughly cylindrical shape, the bag body 4B expands and deforms so that the diameter of the cylinder increases on a plane including the longitudinal direction of the fitting cylindrical portion 4a (the longitudinal direction of the cylindrical axis 30), and so that the height of the cylinder increases in a direction perpendicular to the plane including the longitudinal direction of the fitting cylindrical portion 4a.

[0067] When the bag body 4B expands and deforms at the pipe flow path blocking position, all of the strings 22Aa of the protective sheet 22 are untied, the holding state of the holding portions 22A is released, and the protective sheet 22 deforms in response to the expansion and deformation of the occlusion bag 4. That is, all of the binding portions 22Aa2 of the holding portions 22A of the protective sheet 22 are untied, the protective sheet 22 deforms in response to the expansion and deformation of the bag body 4B, and both circumferential ends are torn and disposed on the upper surface side of the occlusion bag 4. At this time, with the protective sheet 22 blocking the inner peripheral edge portion of the perforation opening 2 on the inner peripheral surface of the water pipe 1, the annular seal portions 4i provided on the outer peripheral surface of the bag body 4B (occlusion bag 4) at positions on both sides of the cylindrical axis 30 in the direction of the pipe axis center X of the water pipe 1 press against the inner peripheral surface of the water pipe 1 over the entire circumferential direction. In this embodiment, the height of the cylinder of the bag body 4B is slightly larger than the length of the protective sheet 22 in a direction perpendicular to a plane including the longitudinal direction of the fitting tubular portion 4a, so that both ends of the blocking bag 4 in the pipe axis X direction are in close contact with the water pipe 1, thereby achieving water-stopping performance.

[0068] In this way, when the occlusion bag 4 inserted into the intra-pipe flow path 3 by the pushing mechanism 40 expands, the protective sheet 22 is released from the holding state of the holding portion 22A and deforms to follow the expansion and deformation of the occlusion bag 4. This allows the desired flow path occlusion function to be achieved without hindering the expansion and deformation of the occlusion bag 4. Furthermore, because a portion of the protective sheet 22 is sandwiched between the distal end surface 50d of the axis alignment member 50 and the proximal end portion 4Ba of the occlusion bag 4, the protective sheet 22 does not fall into the intra-pipe flow path 3. Moreover, because the string 22Aa has knots 22Aa1 at both ends, these knots 22Aa1 are engaged with the multiple notches 22a formed in the protective sheet 22, preventing the string 22Aa from falling into the intra-pipe flow path 3 (see also FIG. 7). When the occlusion bag 4 is sufficiently expanded and deformed, the supply valve 31a is closed.

[0069] Next, when work such as replacing a fire hydrant is completed downstream of the point where the in-pipe flow path 3 is closed by the blocking bag 4, the discharge valve 32a is opened as shown in Fig. 7 to discharge the diameter-expansion fluid P in the bag body 4B to the outside via the fluid supply / discharge path 4c, the flow path 30A, and the discharge path 32, thereby shrinking the bag body 4B in the direction of the pipe axis X of the water pipe 1 and inward in the radial direction. This discharge may be performed by forced suction using a pump or the like, or may be configured to be open to the atmosphere.

[0070] When the occlusion bag 4 contracts, the operating lever 43 of the pushing operation mechanism 40 is operated to release the position of the chain 41, which is in a tightened state, and a crane or the like (not shown) is used to remove the cylindrical shaft 30 along the axis Y of the branch pipe section B. Note that if the operating lever 43 of the pushing operation mechanism 40 is operated to release the position of the chain 41, which is in a tightened state, so that the cylindrical shaft 30 can be removed along the axis Y of the branch pipe section B by the fluid pressure of the clean water Q flowing through the in-pipe flow path 3, there is no need to use a crane or the like, but a configuration in which a crane or the like is used in combination for safety purposes may be used.

[0071] As shown in Figure 7, when the cylindrical shaft 30 is removed, the occlusion bag 4 moves toward the sealed case 20 along the axis Y of the branch pipe section B. At this time, the occlusion bag 4 contracts, folding into a rod shape, and the protective sheet 22, which was positioned above the bag body 4B, deforms to cover the occlusion bag 4 again in accordance with this contracted shape. Because a portion of the protective sheet 22 is sandwiched between the distal end surface 50d of the axis adjustment member 50 and the proximal end portion 4Ba of the occlusion bag 4, the protective sheet 22 deforms smoothly, starting from the sandwiched portion. As a result, the protective sheet 22 can be prevented from coming into contact with burrs on the inner surface of the perforation opening 2 or protrusions on the inner surface of the branch pipe section B, which would otherwise damage the occlusion bag 4.

[0072] 8, the entire occlusion bag 4 is completely housed in the internal space 21 of the sealed case 20. Note that the entire occlusion bag 4 may not be completely housed in the internal space 21 of the sealed case 20, i.e., the tip (part) of the occlusion bag 4 may protrude from the internal space 21 of the sealed case 20 and be located in a position within the cylindrical portion 7a of the gate valve 7 where it does not interfere with the valve element 7C. Thereafter, the valve element 7C is closed, the connection between the bolt 12 and the nut 13 is released, and the sealed case 20 with the occlusion bag 4 housed in the internal space 21 is removed from the annular flange portion 7B of the gate valve 7.

[0073] Therefore, when the blocking bag 4 is inserted into the in-pipe flow path 3 through the perforation opening 2, it does not come into contact with or get caught on burrs at the perforation opening 2 or protrusions at the branch pipe section B, and when it is housed in the sealed case 20 and then removed, it does not come into contact with objects, so it is not damaged or broken. Similarly, when the blocking bag 4 is recovered, it does not come into direct contact with the perforation opening 2, and it can be easily reused.

[0074] 9 shows a protective sheet attachment jig 80. This protective sheet attachment jig 80 is used to sequentially install the holding portion 22A of the protective sheet 22 on the heavy (large-volume) occlusion bag 4. The protective sheet attachment jig 80 includes a bag lifting mechanism 81 that lifts the occlusion bag 4 and a bag squeezer 82 in the shape of a trumpet tube. The bag lifting mechanism 81 includes a fixed housing 81a, a pulley 81c provided at the upper end of the tubular shaft 30, a pair of pulleys 81b provided at the top of the fixed housing 81a, and a chain 81d (or a wire, etc.) that runs between the pair of pulleys 81b and the pulley 81c on the tubular shaft 30. The bag lifting mechanism 81 has both ends of the chain 81d fixed to the bottom of the fixed housing 81a, and can lift the occlusion bag 4 by tightening the chain 81d with an operating device 81e such as a lever block (registered trademark).

[0075] The bag squeezer 82 is formed by an expanding tube 82a whose diameter expands from the fixed housing 81a toward the occlusion bag 4, and a tubular portion 82b having a constant diameter on the fixed housing 81a side of the expanding tube 82a. The occlusion bag 4, which is lifted by the bag lifting mechanism 81, is deformed into a contracted shape folded into a rod as it moves from the expanding tube 82a into the tubular portion 82b. At this time, the occlusion bag 4 is covered with a protective sheet 22. Then, a holding portion 22A (string 22Aa) is sequentially attached to the protective sheet 22 covering the occlusion bag 4 exposed at the top of the tubular portion 82b, thereby maintaining the contracted shape of the occlusion bag 4.

[0076] [Modification] As shown in the first modified example in Figures 10 and 11, the holding portion 22A is made up of connecting tape 22Ab such as Velcro (registered trademark) that connects the divided surfaces 22b of the protective sheet 22, and when the occlusion bag 4 expands, the connecting tape 22Ab comes loose and the holding state is released. The flow path closing method is the same as in the above-mentioned embodiment except for the difference in the structure of the holding portion 22A, so a description thereof will be omitted. In this way, by configuring the holding portion 22A with connecting tape 22Ab that connects the divided surfaces 22b of the protective sheet 22, the efficiency of attaching the protective sheet 22 to the occlusion bag 4 can be improved.

[0077] As shown in the second modified example in FIGS. 12 to 14, the retaining portion 22A is configured with a protective sheet 22 formed of a skirt-shaped one-piece member 22Ac having a hem portion 22Ac1 that is open on the side opposite the base end portion 4Ba of the occlusion bag 4. When the occlusion bag 4 expands, the hem portion 22Ac1 is rolled up, releasing the retaining state. As shown in FIG. 12, if the retaining portion 22A is configured with the protective sheet 22 itself formed of a skirt-shaped one-piece member 22Ac having a hem portion 22Ac1 that is open on the side opposite the base end portion 4Ba, the efficiency of attaching the protective sheet 22 to the occlusion bag 4 can be improved. As shown in FIG. 13, when the bag body 4B abuts against the lower surface of the water pipe 1 and the lower portion naturally expands, the hem portion 22Ac1 of the retaining portion 22A is rolled up, partially releasing the retaining state of the retaining portion 22A. As a result, the protective sheet 22 deforms following the natural deformation of the lower portion of the bag body 4B, and the hem portion 22Ac1 is rolled up. 14, when the bag body 4B expands and deforms at the position where the pipe passage is blocked, the protective sheet 22 deforms in response to the expansion and deformation of the blocking bag 4. Specifically, the bottom portion 22Ac1 of the protective sheet 22 is further rolled up, and the protective sheet 22 moves to the upper surface of the blocking bag 4, and the holding state of the holding portion 22A is released. As a result, the protective sheet 22 can be densely packed near the base end portion 4Ba of the blocking bag 4 (near the perforation opening 2), and even if the blocking bag 4 is pressed so as to move downstream, the protective sheet 22 can reliably prevent the blocking bag 4 from contacting the perforation opening 2.

[0078] Second Embodiment 15 to 18, the closing step will be described in which, after the drilling step, a flow path closing device Aa according to the second embodiment is connected to the gate valve 7 in a watertight state to close the in-pipe flow path 3. The same members as those in the first embodiment will be described using the same reference numerals and names, and detailed description will be omitted.

[0079] As shown in Figure 15, the flow path blocking device Aa comprises a sealed case 200 that is detachably connected to a branch pipe section B that communicates with the perforation opening 2 and has a check valve 7, a cylindrical shaft 30 (an example of a shaft) that is slidably inserted along the axis Y of the branch pipe section B while maintaining a sealed state and has a flow path 30A inside, a nozzle member 4A (an example of a shaft) that has a fitting cylindrical section 4a that is fitted into the tip 30B of the cylindrical shaft 30, a blocking bag 4 that is fixed to the tip 30E of the shaft consisting of the cylindrical shaft 30 and the nozzle member 4A and can be expanded and deformed in the diameter-expanding direction by a diameter-expanding fluid P supplied through the flow path 30A, a pushing operation mechanism 40 that pushes and moves the cylindrical shaft 30 against the fluid pressure of the clean water Q in the water pipe 1, and a cylindrical axis adjustment member 50 that is fitted onto the cylindrical shaft 30 and the nozzle member 4A. In this embodiment, the sealed case 200 is a flow path blocking device Aa that is configured as a divided structure having a connecting flange portion 200A that is connected to the annular flange portion 7B (an example of a flange) of the branch pipe portion B that communicates with the perforation opening 2 and has a check valve 7, and a movable cylinder 200B that can move relative to the connecting flange portion 200A along the axis Y of the branch pipe portion B.

[0080] The connecting flange portion 200A is integrally formed with a flange main body 200Aa, which is detachably and watertightly connected to the annular flange portion 7B downstream of the branch pipe portion B via bolts 12 and nuts 13, and a first annular convex portion 200Ab, whose upstream end protrudes radially inward on the inner periphery of the flange main body 200Aa, and a second annular convex portion 200Ac, whose downstream end protrudes along the axis Y. By having these first annular convex portion 200Ab and second annular convex portion 200Ac, the connecting flange portion 200A forms a seal groove portion 200Ad on the inner periphery into which a seal member S fits, and this seal member S seals the gap between the connecting flange portion 200A and the movable cylinder 200B along the axis Y.

[0081] The movable cylinder 200B is formed in a bottomed cylindrical shape, including a cylindrical wall 200a formed with an inner diameter substantially the same as the inner diameter of the cylindrical portion 7a of the gate valve 7, and a bottom wall portion 200b closing the downstream end of the cylindrical wall 200a. The movable cylinder 200B has an internal space 21A long enough to accommodate a contracted occlusion bag 4. In this embodiment, since it is sufficient to provide only the accommodation space for the occlusion bag 4 in the sealed case 200 (movable cylinder 200B), the dimension of the sealed case 200 in the axial direction Y can be reduced. Note that if the dimension of the gate valve V in the axial direction Y is further reduced to form a more compact shape, the dimension of the movable cylinder 200B in the axial direction Y can be further reduced. In this case, the dimension of the movable cylinder 200B in the axial direction Y can be reduced to a position where the occlusion bag 4 accommodated in the movable cylinder 200B does not interfere with the valve element 7C within the cylindrical portion 7a of the gate valve 7.

[0082] The cylindrical wall 200a has a step 200a1 protruding from the tip end, and a contact protrusion 200a2 (an example of a protrusion) on which an annular member such as a C-ring is fitted downstream of the step 200a1, or a contact protrusion 200a2 (an example of a protrusion) integrally formed and protruding outward from the outer circumferential surface. At least a portion of the outer diameter side of the step 200a1 is configured to be close to the outer peripheral edge 2a of the drilling hole 2. The contact protrusion 200a2 is configured to be able to abut against the first annular protrusion 200Ab of the connecting flange 200A. The cylindrical wall 200a of this embodiment is similar to the cylindrical wall 20a of the first embodiment except for the step 200a1 and the contact protrusion 200a2. The bottom wall 200b is similar to the bottom wall 20b of the first embodiment, so detailed description thereof will be omitted. It is also possible to omit the step portion 200a1 and configure the tip of the cylindrical wall 20a to have a diameter slightly smaller than the inner diameter of the perforation opening 2.

[0083] 15, the connecting flange portion 200A of the sealed case 200 of the flow path closing device Aa is connected in a watertight manner to the annular flange portion 7B downstream of the gate valve 7 via bolts 12 and nuts 13. In this state, the occlusion bag 4, whose contracted shape is maintained by the movable cylinder 200B, is housed in the internal space 21 of the sealed case 20. In this state, the movable cylinder 200B housing the occlusion bag 4 moves downstream (upward) under the fluid pressure of the clean water Q, but the abutting protrusion 200a2 abuts against the first annular protrusion 200Ab of the connecting flange portion 200A, preventing the movable cylinder 200B from slipping out.

[0084] Next, as shown in Figure 16, the valve body 7C is opened, and the chain 41 is wound up to the tightening side using the lower operating lever 43 of the pushing operating mechanism 40, thereby pushing the movable cylinder 200B toward the in-pipe flow path 3 along the axis Y of the branch pipe section B against the fluid pressure of the clean water Q flowing through the in-pipe flow path 3.

[0085] 16 , when the movable cylinder 200B is moved along the axis Y of the branch pipe section B, the movable cylinder 200B moves relative to the connecting flange section 200A, and the step 200a1 approaches the outer peripheral edge 2a of the drilling opening 2. As a result, even when the fluid pressure of the clean water Q flowing through the in-pipe flow path 3 acts on the occlusion bag 4 in an uninterrupted flow state, the outer surface of the occlusion bag 4 is protected by the movable cylinder 200B, and the occlusion bag 4 itself can be moved along the axis Y of the branch pipe section B within the sealing case 20 and the branch pipe section B without coming into contact with the inner surface of the sealing case 20 or the inner surface of the branch pipe section B. Note that the tip surface of the movable cylinder 200B may be rounded to fit the outer periphery of the water pipe 1 so that the step 200a1 covers the inner surface of the drilling opening 2 (the inner surface of the drilling opening 2 in the direction along the pipe axis X of the water pipe 1).

[0086] Thereafter, the chain 41 is further wound up to the tightening side using the upper operating lever 43 of the pushing operation mechanism 40, and the tubular shaft 30 is pushed along the axis Y of the branch pipe section B against the fluid pressure of the clean water Q flowing through the in-pipe flow path 3. When the tubular shaft 30 is further moved along the axis Y of the branch pipe section B toward the in-pipe flow path 3 in this manner, as shown in Figure 17, the occlusion bag 4 fixed to the tip 30E of the shaft formed by the tubular shaft 30 and the nozzle member 4A moves along the axis Y of the branch pipe section B relative to the movable cylinder 200B which abuts against the perforation opening 2 and does not move, and moves toward the in-pipe flow path 3.

[0087] When the step 200a1 of the movable cylinder 200B is close to the outer peripheral edge 2a of the drilling opening 2, the blocking bag 4 is positioned at the intended intra-pipe flow path blocking position in the intra-pipe flow path 3, and the tips of the movable cylinder 200B and the axis adjustment member 50 are positioned at a location corresponding to the drilling opening 2 in the radial direction of the water pipe 1, and the tip of the step 200a1 of the movable cylinder 200B and the tip surface 50d of the axis adjustment member 50 are positioned close to the radial inner end of the water pipe 1 at the drilling opening 2 in the radial direction of the water pipe 1.

[0088] 18, the supply valve 31a is opened to supply a predetermined amount of diameter-expansion fluid P into the bag body 4B of the occlusion bag 4 located at the in-pipe flow path occlusion position via the supply path 31, the flow path 30A, and the fluid supply / discharge path 4c, causing the bag body 4B to expand and deform in the direction of the pipe axis X of the water pipe 1 and radially outward. At this time, the annular seal portions 4i provided on the outer peripheral surface of the bag body 4B (occlusion bag 4) at positions on both sides of the cylinder axis 30 in the direction of the pipe axis X of the water pipe 1 press against the inner peripheral surface of the water pipe 1 over the entire circumferential direction. In this way, the tip of the movable cylinder 200B is located at a position corresponding to the perforation opening 2 in the radial direction of the water pipe 1. Therefore, even if the occlusion bag 4 is pressed downstream by the fluid pressure of the clean water Q in the in-pipe flow path 3 in an uninterrupted flow state, the base end of the occlusion bag 4 fixed to the nozzle member 4A is protected by the tip of the movable cylinder 200B and is prevented from being damaged.

[0089] Next, when work such as replacing a fire hydrant is completed downstream of the point where the pipe flow path 3 is closed by the blocking bag 4, the discharge valve 32a is opened to discharge the diameter-expansion fluid P in the bag body 4B to the outside via the fluid supply / discharge path 4c, the flow path 30A, and the discharge path 32, thereby shrinking the bag body 4B in the pipe axis X direction and radially inward of the water pipe 1. The subsequent procedures are the reverse of those described above, so detailed explanations will be omitted. Note that in this embodiment as well, a protective sheet 22 covering the blocking bag 4 in the first embodiment may be provided.

[0090] [Method of blocking flow path] 19 and 20 , a flow path closing method according to another embodiment will be described. The flow path closing method according to this embodiment includes a drilling step of forming a drilled hole 2 in a water pipe 1 using a cutter of a drilling device connected to a branch pipe section B that is in communication with the drilled hole 2 and has a gate valve 7; a burr removal step of connecting a cutting device C to the branch pipe section B instead of the drilling device and rotating the cutting tool 61 a of the cutting device C while abutting against the inner peripheral edge 2 b of the drilled hole 2 to remove burrs on the inner peripheral edge 2 b; and a closing step of connecting a flow path closing device A to the branch pipe section B instead of the cutting device C, inserting a closing bag 4 into the water pipe 1 through the drilled hole 2, and then inflating the closing bag 4 to close the in-pipe flow path 3. The drilling step is performed in the same manner as the drilling step described above, and the closing step is performed in the same manner as the flow path closing device A according to the first embodiment except that the protective sheet 22 of the flow path closing device A is omitted, and therefore description thereof will be omitted.

[0091] As shown in Figures 19 and 20, the cutting device C used in the burr removal process is equipped with a moving mechanism 6A that can change the cutting bit 61a between a state in which it is in contact with the inner peripheral edge 2b of the drilling hole 2 and a state in which it is spaced apart from the inner peripheral edge 2b of the drilling hole 2, and a rotating mechanism 6B that rotates the cutting bit 61a while it is in contact with the inner peripheral edge 2b of the drilling hole 2.

[0092] The moving mechanism 6A has a rotating member 61 which includes a cutting bit 61a and rotates around a rotating shaft 61b as a fulcrum, a vertical moving shaft 62 which can move in the vertical direction along the axis Y of the branch pipe section B, a spring 63 which applies a tensile force to the rotating member 61, and a holding member 64 which includes a base 64a which holds the vertical moving shaft 62 and an extension 64b which extends from the base 64a parallel to the vertical moving shaft 62.

[0093] The rotating member 61 has a rotating shaft 61b rotatably fixed to the end of the extension 64b, and rotates around this rotating shaft 61b as a fulcrum. A locking shaft 61c to which one end of a spring 63 is locked is threadedly engaged with the rotating member 61, and this locking shaft 61c is configured so that its position can be changed to match the diameter of the drilling hole 2. A nut 62b having a flat outer surface is fixed to the vertically moving shaft 62, and onto which a locking shaft 62a to which the other end of the spring 63 is locked is threadedly engaged.

[0094] As shown by the two-dot chain line in Figure 20, when the vertically movable shaft 62 is in the lowest position, the spring 63 at its natural length causes the rotating member 61 to hang down, and the cutting bit 61a is spaced apart from the inner peripheral edge 2b of the drilling hole 2. As shown by the solid line in Figure 20, by pulling the vertically movable shaft 62 upward, the cutting bit 61a is brought into contact with the inner peripheral edge 2b of the drilling hole 2, and the biasing force of the spring 63 causes the cutting bit 61a to press against the inner peripheral edge 2b of the drilling hole 2.

[0095] The rotation mechanism 6B includes a handle or the like for manually rotating the holding member 64 and the vertically movable shaft 62 while the cutting tool 61a is in contact with the inner peripheral edge 2b of the drilling hole 2. The rotation mechanism 6B may also include a motor or the like for rotating the holding member 64 and the vertically movable shaft 62. By rotating the holding member 64 and the vertically movable shaft 62 with the rotation mechanism 6B, the cutting tool 61a can be rotated along the inner peripheral edge 2b of the drilling hole 2. At this time, the cutting tool 61a presses against the inner peripheral edge 2b of the drilling hole 2 due to the biasing force of the spring 63, so that burrs on the drilling hole 2 are removed by the cutting tool 61a. As described above, in the cutting device C of this embodiment, the biasing force of the spring 63 presses the cutting tool 61a against the inner peripheral edge 2b of the drilling hole 2 and rotates the cutting tool 61a along the inner peripheral edge 2b of the drilling hole 2, so that a deburring process can be provided between the drilling process and the closing process.

[0096] In this way, a burr removal process is included between the drilling process and the closing process, in which burrs on the inner peripheral edge 2b of the drilled opening 2 are removed while the cutting tool 61a of the cutting device C is rotated while being in contact with the inner peripheral edge 2b. Therefore, the blocking bag 4 inserted into the water pipe 1 through the drilled opening 2 after the burrs have been removed is prevented from being damaged even when it comes into contact with the inner surface of the drilled opening 2. Therefore, even if the fluid pressure of the clean water Q in the in-pipe flow path 3 presses the blocking bag 4 downstream in an uninterrupted flow state, the blocking bag 4 comes into contact with the drilled opening 2 from which the burrs have been removed, and therefore damage is prevented.

[0097] [Another embodiment] (1) In the above embodiment, a drilling device is used to drill a drilling hole 2 in the outer surface of the water pipe 1, and the blocking bag 4 is inserted through the drilling hole 2. However, the blocking bag 4 may be inserted through a drilling hole 2 that is formed in advance in the outer surface of the water pipe 1.

[0098] (2) In the above embodiment, the shaft is made up of the cylindrical shaft 30 and the mouthpiece member 4A. However, the shaft may be made up of only the cylindrical shaft 30, with the occlusion bag 4 fixed to the tip of the cylindrical shaft 30.

[0099] (3) In the above embodiment, the axis alignment member 50 is fixed to the tip 30B of the cylindrical shaft 30. However, the axis alignment member 50 may also be fixed to the base end portion 4Ba of the occlusion bag 4 (for example, the bag outer mounting member 4f of the mouthpiece member 4A). Other configurations may be adopted other than the bottomed cylindrical axis alignment member 50, as long as they are members shaped to be able to slide against the inner surface of the sealed case 20.

[0100] (4) In the above embodiment, a lever block (registered trademark) was used as the pushing operation mechanism 40, but other configurations can be used as long as they allow the cylindrical shaft 30 to be pushed in against the fluid pressure from the internal flow path 3.

[0101] (5) In the above embodiment, a water pipe 1 through which clean water Q flows as a fluid is exemplified as a fluid pipe, but the fluid may be a liquid or a gas, and the fluid pipe may be a pipe through which a liquid or a gas can flow. [Industrial Applicability]

[0102] As described above, the present invention can be used as a flow path closing device and a flow path closing method for closing a flow path in a fluid pipe. [Explanation of symbols]

[0103] 1: Water pipe (fluid pipe) 2: Perforation hole 2b: Inner edge 3: Pipe flow path 4: Occlusion bag 4A: Jaw part (shaft) 4Ba: Proximal site 7B: Annular flange part (flange) 20: Sealed case 20A: Connecting flange part 22: Protective sheet 22A: Holding part 22Aa: String 22Ab: Binding tape 22Ac: Skirt-shaped integral member 22Ac1: Hem 22b: Split plane 30: Cylindrical shaft (shaft) 30A: Flow path 30E: Tip 40: Push operation mechanism 50: Axis adjustment member 50d: Tip surface 61a: Cutting tool 200: Sealed case 200A: Connecting flange 200B: Movable tube 200a2: Contact protrusion (protrusion) A: Flow path blocking device Aa: Flow path blocking device B: Branch pipe section C:Cutting device P: Diameter expansion fluid Y: Axial center

Claims

1. A flow path closing device including a closing bag that is inserted into a fluid pipe through a perforation formed in the fluid pipe and that expands and deforms to an enlarged diameter side to close a flow path within the fluid pipe, a sealed case detachably connected to a branch pipe portion that communicates with the perforated opening and has a valve member; a shaft that penetrates the inside of the sealed case along the axis of the branch pipe portion while maintaining a sealed state, and that includes a communication passage therein; the closure bag has a contracted shape that can be accommodated in the sealed case while being fixed to the tip end of the shaft, and is expandable and deformable in the diameter-expanding direction by a diameter-expanding fluid supplied through the communication channel; a pushing operation mechanism that pushes and moves the shaft against the fluid pressure in the fluid pipe; a cylindrical axis alignment member that is fitted onto the axis and has a tip end surface that faces the base end portion of the occlusion bag; a protective sheet including a retaining portion that covers the occlusion bag with a portion of the sheet being sandwiched between the distal end surface and the proximal end surface and that maintains the occlusion bag in a contracted state; When the blocking bag inserted into the fluid pipe by the pushing operation mechanism expands, the protective sheet is released from the holding state of the holding part and deforms in accordance with the expansion and deformation of the blocking bag.

2. the holding portion is formed by a string that binds the divided protective sheet, The flow path blocking device according to claim 1 , wherein when the blocking bag is inflated, the string is untied and the holding state is released.

3. the holding portion is formed of a joining tape that joins the divided surfaces of the protection sheet, 2. The flow path closing device according to claim 1, wherein when the closing bag is inflated, the connection tape is released and the holding state is released.

4. A flow path blocking method using the flow path blocking device according to any one of claims 1 to 3, a drilling step of forming the drilling hole in the fluid pipe by a cutter of a drilling device connected to the branch pipe portion; a burr removal process in which a cutting device is connected to the branch pipe portion instead of the drilling device, and a cutting tool of the cutting device is rotated in a state in which it is in contact with the inner peripheral edge of the drilling hole, thereby removing burrs on the inner peripheral edge; a closing step of connecting the flow path closing device to the branch pipe section instead of the cutting device, inserting the closing bag into the fluid pipe through the perforation opening, and then inflating the closing bag to close the flow path within the pipe.

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