Branch channel blocking device and method for removing the branch channel blocking device

Abstract

To provide a branch flow path closing device capable of being used even in a place where there is an obstacle at an upper part of a work space, and a method for removing a branch flow path closing device.SOLUTION: A branch flow path closing device X for closing a flow path of a branch pipe part branched from a fluid pipe, comprises a partition valve, a work case 30, a locking mechanism 4, a seal mechanism 5, and a shaft member 7. The work case 30 is a divided body obtained by dividing the shaft member 7 along an axial core Y direction, and divided parts of the divided body sandwich the shaft member 7 in a sealed state.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a branch flow path blocking device for blocking the flow path of a branch pipe portion branched from a fluid pipe, and a method for removing the branch flow path blocking device.

Background Art

[0002] Conventionally, existing fluid equipment composed of a shut-off valve (repair valve, etc.) installed in a branch pipe portion of a fluid pipe (water pipe, etc.), an air valve installed above the shut-off valve, or a fire hydrant, etc. has reached its service life, etc. A branch flow path blocking device used when replacing it with a new fluid device (updating the fluid device) is known (see, for example, Patent Document 1).

[0003] The branch flow path blocking device described in Patent Document 1 includes an outer operation shaft, an inner operation shaft inserted into the outer operation shaft, a stopper locking means locked to the connection portion between the branch pipe portion and the fluid pipe by operating the outer operation shaft and the inner operation shaft, and a sealing material that is elastically deformed in the diameter expansion direction by relatively moving the outer operation shaft with respect to the inner operation shaft to block the flow path of the branch pipe portion. The outer operation shaft and the inner operation shaft are divided so as to be additively connected, and the work efficiency can be improved even in a place with a small work space.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The branch channel blocking device described in Patent Document 1 can be used even in places with limited workspace because the outer and inner operating shafts are separated so that they can be joined together. However, there was room for improvement in removing the device after the flow path of the branch pipe section has been blocked with a sealing material. In other words, if there is an obstacle such as a ceiling wall above the workspace, even if the operating shaft above the work case is removed, there may not be enough space between the upper end of the operating shaft and the ceiling wall to remove the work case.

[0006] Therefore, there is a need for a branch channel blocking device that can be used even in locations where there are obstacles above the workspace, and a method for removing the branch channel blocking device. [Means for solving the problem]

[0007] The characteristic configuration of the branch channel blocking device according to the present invention is a branch channel blocking device for blocking the flow path of a branch pipe section branched from a fluid pipe, comprising: a gate valve detachably connected to the branch pipe section; a work case detachably connected to the gate valve; a locking mechanism that engages with the connection portion between the branch pipe section and the fluid pipe; a seal mechanism having an elastic member capable of blocking the flow path of the branch pipe section; a shaft member having a first shaft member that supports the locking mechanism and the seal mechanism, and a second shaft member connected to the first shaft member, wherein the work case is a divided body divided along the axial direction of the shaft member, and the shaft member is held in a sealed state by the divided portion of the divided body.

[0008] In this configuration, a locking mechanism that engages with the connection between the branch pipe and the fluid pipe prevents upward movement of the shaft member due to fluid pressure, and a sealing mechanism that closes the flow path of the branch pipe prevents downward movement of the shaft member. As a result, by attaching the branch flow path occlusion device to the branch pipe, fluid equipment can be replaced while preventing fluid leakage from the branch pipe.

[0009] Furthermore, the work case is a divided body that is split along the axial direction of the shaft member, and the shaft member is held in a sealed state at the divided portion of the divided body. Therefore, the work case can be removed to the side of the shaft member. In other words, there is no need to remove the work case from the upper end of the shaft member along the axial direction, and the work case can be removed without interfering with obstacles even in places where there are obstacles above the workspace. Also, since the shaft member is divided into a first shaft member and a second shaft member, the gate valve can be removed without interfering with obstacles by removing the second shaft member. Thus, this branch channel occlusion device can be used even in places where there are obstacles above the workspace.

[0010] Other characteristic features include the fact that the work case includes a first split case and a second split case, the first split case having a split first split member, a pair of first protrusions projecting radially outward from both circumferential ends of the first split member, and a first connecting flange portion connected to the flange of the gate valve, the second split case having a split second split member, a pair of second protrusions projecting radially outward from both circumferential ends of the second split member, and a second connecting flange portion connected to the flange, and sealing members are arranged continuously on the mating surfaces of the first protrusions and the second protrusions, and on the surfaces of the first connecting flange portion and the second connecting flange portion facing the flange.

[0011] In this configuration, since sealing members are continuously arranged on the mating surfaces of the first and second protrusions, and on the opposing surfaces of the gate valve flanges in the first and second connecting flanges, the sealing function at the split surface and flange surface of the divided body can be reliably achieved.

[0012] Other characteristic features include the fact that the work case has a connecting flange portion connected to the flange of the gate valve, a cylindrical body extending in the axial direction from the inner circumference of the connecting flange portion, and a bottom wall portion extending inward from the end of the cylindrical body opposite to the connecting flange portion, and the shaft member is held in a sealed state between the divided portion of the bottom wall portion.

[0013] As shown in this configuration, by clamping the shaft member in a sealed state at the divided portion of the bottom wall, the work case can be made more compact.

[0014] Other characteristic features include the fact that the work case has a connecting flange portion connected to the flange of the gate valve, a cylindrical body extending in the axial direction from the inner circumference of the connecting flange portion, an annular projection portion projecting outward in an annular shape from the end of the cylindrical body opposite to the connecting flange portion, and a divided plate-like member connected to the annular projection portion, and the shaft member is held in a sealed state between the divided portion of the divided plate-like member.

[0015] As in this configuration, by separately providing a divided plate-shaped member connected to the annular projection, it becomes possible to clamp the shaft member with this divided plate-shaped member so as to cover the opening of the branch pipe section after removing the work case and gate valve, thereby stabilizing the sealing function of the sealing mechanism.

[0016] A feature of the branch channel blocking method using any of the branch channel blocking devices described above according to the present invention is that it includes a blocking step of blocking the channel of the branch pipe section with the sealing mechanism while the locking mechanism is locked to the connection portion, a case removal step of removing the work case connected to the gate valve in a direction intersecting the axial direction after the blocking step, and a gate valve removal step of removing the second shaft member and then removing the gate valve along the axial direction after the case removal step.

[0017] In the occlusion process of this method, the upward movement of the shaft member due to fluid pressure is prevented by engaging a locking mechanism at the connection point between the branch pipe and the fluid pipe, and the downward movement of the shaft member is prevented by supplying fluid to the seal mechanism and occluding the flow path of the branch pipe. As a result, the work case and gate valve can be removed after the occlusion process is completed.

[0018] Also, in the case removal step of this method, since the work case is removed in a direction intersecting the axial direction, even in a place where there is an obstacle above the work space, the work case can be removed without interfering with the obstacle. Further, in the partition valve removal step of this method, after the case removal step, the second shaft member is removed and then the partition valve is removed along the axial direction, so the space where the work case was located can be utilized to pull out the partition valve. Thus, it is a method for removing the branch flow path blocking device that can be used even in a place where there is an obstacle above the work space.

Brief Description of the Drawings

[0019] [Figure 1] It is a side view showing an existing fluid device. [Figure 2] It is a side cross-sectional view showing the branch flow path blocking device according to this embodiment. [Figure 3] It is an exploded perspective view of the work case. [Figure 4] It is a view showing a divided plate-like member. [Figure 5] It is a front view of the branch flow path blocking device. [Figure 6] It is a side view of the branch flow path blocking device. [Figure 7] It is a cross-sectional view of the seal mechanism. [Figure 8] It is a side cross-sectional view showing the operating procedure of the branch flow path blocking device. [Figure 9] It is a side view showing the temporary blocking step and the removal step. [Figure 10] It is a side cross-sectional view showing the mounting step. [Figure 11] It is a side cross-sectional view showing the locking step and the blocking step. [Figure 12] It is a side cross-sectional view showing the first removal step. [Figure 13] It is a side cross-sectional view showing the first installation step. [Figure 14] It is a partial side cross-sectional view showing the second removal step. [Figure 15] It is a side view showing the second installation step. [Figure 16]This is a side cross-sectional view showing the divided plate-shaped member attached to the branch pipe section. [Figure 17] This figure shows a work case according to a different embodiment. [Modes for carrying out the invention]

[0020] The following describes embodiments of a branch channel blocking device and a branch channel blocking method, including a method for removing the branch channel blocking device, according to the present invention, based on the drawings. In this embodiment, an example of using the branch channel blocking device to replace air valves and gate valves constituting fluid equipment is described. However, the invention is not limited to the following embodiments, and various modifications are possible without departing from the gist of the invention. In the following, the direction of gravity may be described as down, and the direction opposite to the direction of gravity may be described as up.

[0021] As shown in Figure 1, the upstream (lower) connecting flange portion 3a of the gate valve 3 is detachably and securely fastened in a sealed state to the connecting flange portion 2c of the branch pipe section 2, which is formed to protrude radially outward in the middle of the water pipe 1 (an example of a fluid pipe), using bolts and nuts. In addition, the downstream (upper) connecting flange portion 3b of the gate valve 3 is detachably and securely fastened in a sealed state to the connecting flange portion 6a of the air valve 6 (existing fluid equipment) using bolts and nuts.

[0022] In this embodiment, while maintaining an uninterrupted water flow in the water pipe 1, the existing gate valve 3 and air valve 6 are replaced with new repair valves 8 and air valve 9 (new fluid equipment) using the branch channel blocking device X described later, when they reach their set service life or due to leaks or malfunctions caused by deterioration (see Figure 15).

[0023] Figure 2 shows a side cross-sectional view of the branch channel blocking device X. The branch channel blocking device X blocks the flow path of the branch pipe section 2 that branches off from the water pipe 1 described above (see also Figure 11). The branch channel blocking device X includes a locking mechanism 4 that engages with the connection portion 2a between the branch pipe section 2 and the water pipe 1, a sealing mechanism 5 capable of blocking the flow path of the branch pipe section 2, a shaft member 7 that supports the locking mechanism 4 and the sealing mechanism 5 and is composed of an inner cylinder shaft 7A and an outer cylinder shaft 7B, and a holding member 15 that holds the shaft member 7. As will be described in detail later, the sealing mechanism 5 in this embodiment has a fluid inlet 51 into which air (an example of a fluid) flows in, and the air flowing in from the fluid inlet 51 expands radially outward and blocks the flow path of the branch pipe section 2.

[0024] The locking mechanism 4 includes a plate-shaped member 41 provided at the upstream end (lower end) that the tip of the inner cylinder shaft 7A abuts against to restrict its movement, a guide member 42 to which the plate-shaped member 41 is fixed and which the inner cylinder shaft 7A is movably inserted, a spring 43 disposed inside the guide member 42, and a plurality of locking links 44 (two in the circumferential direction in this embodiment) that are swingably connected to the radially outward side of the spring 43 outside the guide member 42.

[0025] The plate-shaped member 41 is fixed to the upstream end face (bottom surface) of the guide member 42 (the rod-shaped member 42a, described later). The tip of the inner cylinder shaft 7A, which has been moved by the biasing force of the spring 43, comes into contact with the downstream end face (top surface) of the plate-shaped member 41, thereby restricting the downward movement of the inner cylinder shaft 7A. One end of a pair of upstream locking links 44 is pivotally connected to both the left and right ends of the plate-shaped member 41 so as to be able to swing freely.

[0026] The guide member 42 has a plurality (four in this embodiment) of rod-shaped members 42a, one end of which is fixed to a tip plate 55 (described later) and the other end of which is fixed to a plate-shaped member 41, and a slide member 42b that is supported between the plurality of rod-shaped members 42a and is slidable in the axial direction. Inside the plurality of rod-shaped members 42a, a part of a movable inner cylindrical shaft 7A and a spring 43 arranged on the outer circumference of this inner cylindrical shaft 7A are housed. In addition, the other ends of a pair of downstream locking links 44 are pivotally connected to both the left and right ends of the slide member 42b so as to be able to swing.

[0027] As shown in the left and center diagrams of Figure 8, the locking link 44 can extend into an expanded diameter position in conjunction with the downstream (upward) movement of the inner cylinder shaft 7A. In the expanded diameter position, the locking link 44 engages with the inner circumferential wall surface of the branch pipe section 2 upstream of the branch channel blockage point by the sealing mechanism 5, that is, with the periphery of the branch channel opening (connection portion 2a) on the inner circumferential surface of the branch pipe section 2. At this time, the release prevention mechanism 10, which will be described later, maintains the tip of the inner cylinder shaft 7A in a state separated from the plate-shaped member 41.

[0028] As shown in Figures 2 and 7, the sealing mechanism 5 includes a pair of upper annular members 5A, a pair of lower annular members 5B, a hollow cylindrical member 54, a tip plate 55, and an elastic member 5C positioned between the upper annular members 5A and the lower annular members 5B.

[0029] The pair of upper annular members 5A consists of a first disc-shaped member 5Aa (first annular member) and a first water-stopping fitting 5Ab (first support part) connected to the first disc-shaped member 5Aa by a plurality of (eight in this embodiment) hex socket head bolts, etc., forming a pull bolt 52. The pair of lower annular members 5B consists of a second disc-shaped member 5Ba (second annular member) and a second water-stopping fitting 5Bb (second support part) connected to the second disc-shaped member 5Ba by a plurality of (eight in this embodiment) pull bolts 53, 55a. In this embodiment, the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb have a divisible structure that allows relative movement by screwing the pull bolts 52 and / or pull bolts 53, 55a into each other.

[0030] As shown in Figure 7, the first disc-shaped member 5Aa is integrally formed with a base portion 56a, whose upstream end face (bottom surface) is concave, and an extension portion 56b that extends downstream (upward) from the base portion 56a. The base portion 56a has multiple (eight in this embodiment) through holes 56a1 formed at equal intervals in the circumferential direction, into which a pull bolt 52 is inserted in an annular portion adjacent to the extension portion 56b. The inner circumferential sealing member sa, which is attached to the inner circumferential surface of the holding member 15, is in contact with the outer circumferential surface of the extension portion 56b, and the inner cylindrical shaft 7A is facing the inner circumferential surface of the extension portion 56b. A male threaded portion 56b1 is formed on the outer circumferential surface of the downstream end (upper end) of the extension portion 56b. The female threaded portion 7Ba formed on the inner circumferential surface of the upstream end (lower end) of the outer cylinder shaft 7B is screwed into this male threaded portion 56b1, thereby connecting the first disc-shaped member 5Aa and the outer cylinder shaft 7B. In other words, the first disc-shaped member 5Aa is supported by the outer cylinder shaft 7B. Furthermore, a seal groove 56b2 for mounting an O-ring sb is formed on the outer circumferential surface of the downstream end (upper end) of the extension portion 56b, upstream (below) the male threaded portion 56b1, and a tapered surface 56b5 for compressing the O-ring sh is formed downstream (above) the male threaded portion 56b1.

[0031] A female threaded portion 56b3 is formed on the inner circumferential surface of the upstream end (lower end) of the extension portion 56b, and is screwed into a male threaded portion 54a formed on the outer circumferential surface of the downstream end (upper end) of the hollow cylindrical member 54, thereby connecting the first disc-shaped member 5Aa and the hollow cylindrical member 54. In other words, the hollow cylindrical member 54 is also supported by the outer cylindrical shaft 7B via the first disc-shaped member 5Aa. Furthermore, a seal groove 56b4 is formed on the inner circumferential surface of the upstream end (lower end) of the extension portion 56b, downstream (above) of the female threaded portion 56b3, into which an O-ring sc is fitted. When the first disc-shaped member 5Aa and the hollow cylindrical member 54 are connected, the tapered surface 54a1 formed on the downstream end (upper end) of the male threaded portion 54a of the hollow cylindrical member 54 comes into contact with and compresses the O-ring sc.

[0032] The first water-stopping fitting 5Ab is cup-shaped and integrally formed with a disc base 57a and a cylindrical portion 57b extending upstream (downward) from the outermost circumference of the disc base 57a. The disc base 57a has an insertion hole 57a1 through its center into which a hollow cylindrical member 54 is inserted, and a first stepped portion 57a2 is formed on the outermost circumference into which one end of the elastic member 5C engages. Furthermore, a seal groove 57a3 into which an O-ring sd is fitted is formed on the outer circumference adjacent to the insertion hole 57a1 of the disc base 57a, and further outward from this seal groove 57a3, a plurality (eight in this embodiment) of female screw holes 57a4 into which a pull bolt 52 is screwed are formed at equal intervals in the circumferential direction. The cylindrical portion 57b is adjacent to the outside of the second water-stopping fitting 5Bb and forms an outer cylinder into which the second water-stopping fitting 5Bb is inserted.

[0033] The second disc-shaped member 5Ba has a concave shape on its downstream end face (upper surface). The second disc-shaped member 5Ba has an insertion hole 58a through its center into which the hollow cylindrical member 54 is inserted. On the outer circumference of the insertion hole 58a, there are multiple (eight in this embodiment) through holes 58b, into which pull bolts 53 and 55a, made of hexagon socket head bolts or the like, are inserted, and these holes are formed at equal intervals in the circumferential direction. On the inner circumferential surface of the insertion hole 58a, there is a seal groove 58a1 into which an O-ring sj ​​is fitted, and on the upstream (lower) side of the seal groove 58a1, there is a locking recess 58a2 into which the hollow cylindrical member 54 is locked. In other words, the second disc-shaped member 5Ba is also supported by the outer cylindrical shaft 7B via the first disc-shaped member 5Aa and the hollow cylindrical member 54.

[0034] The second water-stopping fitting 5Bb has an insertion hole 59a formed through the center into which a hollow cylindrical member 54 is inserted, and a second stepped portion 59b formed on the outermost side into which the other end of the elastic member 5C engages. Furthermore, a seal groove 59c into which an O-ring sf is fitted is formed on the outer side adjacent to the insertion hole 59a, and further outward from this seal groove 59c, a plurality (eight in this embodiment) of female screw holes 59d are formed at equal intervals in the circumferential direction into which the pull bolts 53 and 55a are screwed. The second water-stopping fitting 5Bb is adjacent to the inside of the cylindrical portion 57b of the first water-stopping fitting 5Ab and is an inner cylinder into which the cylindrical portion 57b is externally fitted.

[0035] The hollow cylindrical member 54 has a pair of upper annular members 5A and a pair of lower annular members 5B fitted onto it, and an inner cylindrical shaft 7A fitted inside it. Near the axial center of the hollow cylindrical member 54, a plurality of through holes are formed as a fluid inlet 51 that communicates with a fluid introduction space A for expanding the elastic member 5C. The hollow cylindrical member 54 also has a male threaded portion 54a at one end that screws into a female threaded portion 56b3 formed on the extension portion 56b of the first disc-shaped member 5Aa, and an annular projection 54b at the other end that engages with a locking recess 58a2 formed on the second disc-shaped member 5Ba. The hollow cylindrical member 54 is inserted into the first water-stopping fitting 5Ab and the pair of lower annular members 5B, and with the annular projection 54b and the locking recess 58a2 engaged, the hollow cylindrical member 54 is screwed onto the first disc-shaped member 5Aa, thereby positioning the first disc-shaped member 5Aa and the second disc-shaped member 5Ba. Furthermore, the hollow cylindrical member 54 is prevented from falling by the tip plate 55, which is fixed to the second disc-shaped member 5Ba by a number of (four in this embodiment) pull bolts 55a, such as hex socket head bolts.

[0036] The tip plate 55 has an insertion hole 55b formed through the center into which the inner cylinder shaft 7A is inserted, and multiple (four in this embodiment) through holes 55c for accommodating the heads of the pull bolts 53 and multiple (four in this embodiment) through holes (not shown) for inserting the male threads of the pull bolts 55a are alternately arranged in the circumferential direction. Furthermore, the rod-shaped member 42a of the guide member 42 is screw-fixed to the upstream end face (bottom surface) of the tip plate 55 (see also Figure 2), and a seal groove 55d is formed on the downstream end face (top surface) of the tip plate 55 between the insertion hole 55b and the through hole 55c, into which an O-ring sg is fitted. A seal groove 55e is formed on the inner circumferential surface of the insertion hole 55b into which an outer circumferential seal member si is fitted, and this outer circumferential seal member si is in close contact with the inner cylinder shaft 7A.

[0037] The elastic member 5C is made of a highly durable synthetic rubber such as ethylene propylene diene rubber (EPDM), and has a first clamped portion 61 that is sandwiched between a pair of upper annular members 5A, a second clamped portion 62 that is sandwiched between a pair of lower annular members 5B, and an expansion portion 63 that connects the first clamped portion 61 and the second clamped portion 62 and expands when air flows in from the fluid inlet portion 51.

[0038] The first clamped portion 61 is bent inward from the expanding portion 63 in an L-shape cross-section, and similarly, the second clamped portion 62 is bent inward from the expanding portion 63 in an L-shape cross-section. By engaging the first clamped portion 61 with the first stepped portion 57a2 of the first water-stopping fitting 5Ab, and engaging the second clamped portion 62 with the second stepped portion 59b of the second water-stopping fitting 5Bb, one end of the elastic member 5C is supported by the first water-stopping fitting 5Ab, and the other end of the elastic member 5C is supported by the second water-stopping fitting 5Bb. The expanding portion 63 is in a bent shape in its natural state, and by tightening the pull-in bolts 52 and / or pull-in bolts 53, 55a to separate the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb, it becomes an upright shape.

[0039] The procedure for correcting the posture of the elastic member 5C is described below. The first clamped portion 61 is engaged with the first stepped portion 57a2 of the first water-stopping fitting 5Ab, and the second clamped portion 62 is engaged with the second stepped portion 59b of the second water-stopping fitting 5Bb. The hollow cylindrical member 54 is then installed inside the pair of upper annular members 5A and the pair of lower annular members 5B, and temporarily tightened with the pull-in bolts 52 and 53, 55a. In this state, the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb are close together, and the expanded portion 63 is in a bent and deformed shape. Next, by further tightening the pull-in bolts 52 and 53, 55a, the first water-stopping fitting 5Ab comes into contact with the first disc-shaped member 5Aa, and the second water-stopping fitting 5Bb comes into contact with the second disc-shaped member 5Ba, causing the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb to separate. As a result, a tensile force is applied to the expansion section 63, causing it to become upright. With this configuration, the sealed space enclosed by the hollow cylindrical member 54, the first water-stopping fitting 5Ab, and the second water-stopping fitting 5Bb becomes the fluid introduction space A.

[0040] As shown in the right-hand diagram of Figure 8, the expansion section 63 expands radially outward due to the fluid pressure caused by the air introduced into the fluid introduction space A from the outer cylinder shaft 7B via the fluid inlet 51. In this way, by separating the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb while supporting the elastic member 5C and applying tension to the elastic member 5C, it is possible to prevent deformation of the elastic member 5C before expansion. As a result, when the elastic member 5C is expanded by introducing air from the fluid inlet 51, it is possible to expand the elastic member 5C evenly, and the flow path of the branch pipe section 2 can be reliably closed. The expansion rate and strength of the expansion section 63 are designed according to the structure and inner diameter of the branch pipe section 2.

[0041] Returning to Figure 2, the inner cylinder shaft 7A is composed of a solid rod-shaped member that penetrates the central part of the holding member 15, which is fixed to the divided plate-shaped member 31 of the work case 30 (described later), in a sealed state in the axial direction. Because the height of the working space from the upper surface of the air valve 6 to the ceiling wall R of the structure is limited, the inner cylinder shaft is composed of divided inner cylinder shafts 7A1 and 7A2 that are divided in the axial direction to correspond to this limited height of the working space. The inner cylinder shaft 7A has at least a first divided inner cylinder shaft 7A1 (an example of a first shaft member) which is provided with a locking mechanism 4 and a sealing mechanism 5, and a second divided inner cylinder shaft 7A2 (an example of a first shaft member) which is connected to the upper end of the first divided inner cylinder shaft 7A1 by a connecting part 11 which is composed of male and female screw connections. Furthermore, it is possible to connect a dividing operation shaft (an example of a second shaft member) to the upper end of the second divided inner cylinder shaft 7A2.

[0042] The outer cylindrical shaft 7B is composed of a hollow rod-shaped member that slidably penetrates the central part of the holding member 15, which is fixed to the divided plate-shaped member 31 of the work case 30 (described later), in a sealed state. The inner cylindrical shaft 7A is inserted into the outer cylindrical shaft 7B with the same axis Y as the inner cylindrical shaft 7A, and a fluid flow path F communicating with the fluid inlet 51 is formed in the gap between the inner cylindrical shaft 7A and the outer cylindrical shaft 7B.

[0043] The outer cylinder shaft 7B, like the inner cylinder shaft 7A, is composed of multiple outer cylinder shafts 7B1 and 7B2 that are divided axially to correspond to the height restriction of the working space. The outer cylinder shaft 7B is connected to the sealing mechanism 5 by screwing a female threaded portion 7Ba formed on the inner circumferential surface of the upstream end (lower end) of the outer cylinder shaft 7B into a male threaded portion 56b1 of the first disc-shaped member 5Aa. The outer cylinder shaft 7B also has at least a first divided outer cylinder shaft 7B1 (an example of the first shaft member) which is provided with a locking mechanism 4, a sealing mechanism 5, and a holding member 15, and a second divided outer cylinder shaft 7B2 (an example of the first shaft member) which is connected to the upper end of the first divided outer cylinder shaft 7B1 by a connecting portion 12 which is configured as a male-female threaded connection. A coupler 13a for supplying air from a fluid supply mechanism 13 such as an air pump is connected to the upper end of the second divided outer cylinder shaft 7B2. It is also possible to connect a further dividing operation shaft (an example of the second shaft member) to the upper end of the second divided outer cylinder shaft 7B2.

[0044] A release prevention mechanism 10 is provided across the inner cylinder shaft 7A and the outer cylinder shaft 7B to prevent the locking mechanism 4 from being released. The release prevention mechanism 10 consists of a male threaded portion 7Aa formed on the downstream end (upper end) of the inner cylinder shaft 7A, an operating nut 10A that is screwed onto the male threaded portion 7Aa, and a bearing 7Bb positioned on the downstream end face (upper surface) of the outer cylinder shaft 7B to support the rotation of the operating nut 10A. The locking mechanism 4 is also configured so that a pair of locking links 44 can be expanded in diameter by rotating the operating nut 10A. By rotating the operating nut 10A while sliding it against the bearing 7Bb, the inner cylinder shaft 7A rises, the pair of locking links 44 expand in diameter, and these locking links 44 engage with the periphery of the branch flow path opening on the inner circumferential surface of the branch pipe section 2 (see also Figure 11). Then, when the operating nut 10A becomes unable to rotate, the locking mechanism 4 is locked, and the locking state of the locking mechanism 4 is prevented from being released by the operating nut 10A and the male threaded portion 7Aa. In this way, expanding the diameter of the locking mechanism 4 by rotating the operating nut 10A provides excellent operability, and it is easy to confirm that the locking of the locking mechanism 4 is complete when the operating nut 10A becomes unable to rotate. Alternatively, the bearing 7Bb as the release prevention mechanism 10 may be omitted, and the operating nut 10A may be made to slide against the downstream end face (upper surface) of the outer cylinder shaft 7B.

[0045] The retaining member 15 is a disc-shaped member that holds the outer cylindrical shaft 7B and is fixed to the divided plate-shaped member 31 of the work case 30 (described later) with fixing bolts 24C. The retaining member 15 has a through hole 15a for the outer cylindrical shaft formed in its central portion into which the outer cylindrical shaft 7B is inserted. An inner circumferential sealing member sa is attached to the inner circumferential surface of the through hole 15a for the outer cylindrical shaft, and this inner circumferential sealing member sa holds the outer cylindrical shaft 7B in a sealed state relative to the retaining member 15. In addition, an outer circumferential sealing member se is provided in the annular groove on the outer circumferential surface of the retaining member 15, preventing water leakage from the gap between the work case 30 and the retaining member 15.

[0046] The branch channel blocking device X described above includes a work case 30 that is detachably connected to the gate valve 3. The work case 30 is a housing having a connecting flange portion 30a connected to the connecting flange portion 3b on the downstream (upper) side of the gate valve 3, a cylindrical body 30b extending from the inner circumference of the connecting flange portion 30a in the direction of the axis Y of the shaft member 7, and an annular projection portion 30c that protrudes outward in an annular shape from the end of the cylindrical body 30b opposite to the connecting flange portion 30a. In addition, a drain valve 22 is connected to the side wall of the work case 30 to discharge rust deposits and the like scraped off by a scraping cleaning tool (not shown) to the outside (see also Figure 6).

[0047] In this embodiment, the work case 30 is a divided body composed of a first divided case 30A and a second divided case 30B, which are divided along the axis Y direction of the shaft member 7, and the shaft member 7 is held in a sealed state between the divided portions of the divided body.

[0048] As shown in Figure 3, a pipe 22a connected to the drain valve 22 described above is provided on the side wall of the first split case 30A. The first split case 30A has a split first split member 30Aa, a pair of first protrusions 30Ab projecting radially outward from both circumferential ends of the first split member 30Aa, a first connecting flange portion 30Ac connected to the connecting flange portion 3b (an example of a flange) on the downstream (upper) side of the gate valve 3, and a first annular protrusion 30Ad located on the opposite side of the first connecting flange portion 30Ac to which the split plate-shaped member 31 described later is connected. These first split member 30Aa, first protrusions 30Ab, first connecting flange portion 30Ac, and first annular protrusion 30Ad are integrally formed. The second split case 30B has a halved second split member 30Ba, a pair of second protrusions 30Bb projecting radially outward from both circumferential ends of the second split member 30Ba, a second connecting flange portion 30Bc connected to the downstream (upper) connecting flange portion 3b (an example of a flange) of the gate valve 3, and a second annular protrusion 30Bd located on the opposite side of the second connecting flange portion 30Bc to which the split plate-shaped member 31, described later, is connected. These second split member 30Ba, second protrusions 30Bb, second connecting flange portion 30Bc, and second annular protrusion 30Bd are integrally formed.

[0049] The first connecting flange portion 30Ac and the second connecting flange portion 30Bc have multiple through holes (in this embodiment, a combination of four and two, respectively) for connecting to the downstream (upper) connecting flange portion 3b of the gate valve 3 with bolts and nuts. The first protrusion portion 30Ab and the second protrusion portion 30Bb have multiple through holes (in this embodiment, eight, respectively) for connecting to each other with bolts B, which are made of hex socket head bolts (see also Figure 5). The first annular protrusion portion 30Ad and the second annular protrusion portion 30Bd have multiple through holes (in this embodiment, a combination of four and two, respectively) for connecting to the divided plate-shaped member 31 with connecting members 33, which are made of bolts and nuts.

[0050] Thus, the connecting flange portion 30a of the work case 30 is composed of the first connecting flange portion 30Ac of the first divided case 30A and the second connecting flange portion 30Bc of the second divided case 30B. The cylindrical body 30b of the work case 30 is composed of the first half-split member 30Aa and a pair of first protrusions 30Ab of the first divided case 30A, and the second half-split member 30Ba and a pair of second protrusions 30Bb of the second divided case 30B. The annular protrusion 30c of the work case 30 is composed of the first annular protrusion 30Ad of the first divided case 30A and the second annular protrusion 30Bd of the second divided case 30B.

[0051] One of the pair of first protrusions 30Ab has a first linear seal groove 30Ab1 formed on the mating surface 30Ab2 with the second protrusion 30Bb, and a first semicircular seal groove 30Ac1 is formed on the surface of the first connecting flange portion 30Ac that faces the downstream (upper) connecting flange portion 3b of the gate valve 3. One of the pair of second protrusions 30Bb has a second linear seal groove 30Bb1 formed on the mating surface 30Bb2 with the first protrusion 30Ab, and a second semicircular seal groove 30Bc1 is formed on the surface of the second connecting flange portion 30Bc that faces the downstream (upper) connecting flange portion 3b of the gate valve 3.

[0052] A first sealing member S1 is fitted into the first linear sealing groove 30Ab1 and the first semicircular sealing groove 30Ac1, and a second sealing member S2 is fitted into the second linear sealing groove 30Bb1 and the second semicircular sealing groove 30Bc1. The first sealing member S1 has a first linear sealing portion S1a that fits into the first linear sealing groove 30Ab1 and a first semicircular portion S1b of an annular seal that fits into the first semicircular sealing groove 30Ac1, which are in close contact. Similarly, the second sealing member S2 has a second linear sealing portion S2a that fits into the second linear sealing groove 30Bb1 and a second semicircular portion S2b of an annular seal that fits into the second semicircular sealing groove 30Bc1, which are in close contact. In other words, the sealing members S1 and S2 are arranged continuously on the mating surfaces 30Ab2 and 30Bb2 of the first protrusion 30Ab and the second protrusion 30Bb, and on the surfaces of the first connecting flange portion 30Ac and the second connecting flange portion 30Bc that face the connecting flange portion 3b on the downstream (upper) side of the gate valve 3.

[0053] As shown in Figure 2, the branch channel blocking device X in this embodiment is connected to the annular projection 30c of the work case 30 and further comprises a divided plate-shaped member 31 that is divided into a half-disc shape. This divided plate-shaped member 31 functions as part of the work case 30 by being connected to the annular projection 30c. The shaft member 7 is held in a sealed state by being sandwiched between the divided portions of the divided plate-shaped member 31. In other words, the shaft member 7 is held in a sealed state by being sandwiched between the divided portions of the divided plate-shaped member 31, which is a divided part of the work case 30.

[0054] As shown in Figure 4, the divided plate-shaped member 31 is composed of a first plate-shaped member 31A and a second plate-shaped member 31B, both having a half-disc shape. The first plate-shaped member 31A is integrally formed with a first semicircular portion 31Aa facing the annular projection 30c of the work case 30 and a pair of first block portions 31Ab protruding from the inner end of the first semicircular portion 31Aa on the opposite side from the annular projection 30c. The second plate-shaped member 31B is integrally formed with a second semicircular portion 31Ba facing the annular projection 30c of the work case 30 and a pair of second block portions 31Bb protruding from the inner end of the second semicircular portion 31Ba on the opposite side from the annular projection 30c. The first plate-shaped member 31A and the second plate-shaped member 31B are connected by a plurality (four in this embodiment) of fastening members 32, which are made of hex socket head bolts, with a pair of first block portions 31Ab and a pair of second block portions 31Bb facing each other, to form a divided plate-shaped member 31 (see also Figure 6).

[0055] The bottom surface of the divided plate-shaped member 31 has an annular recess 31a formed on the central side for accommodating the retaining member 15, and an annular seal groove 31b formed on the outer circumference side of the annular recess 31a for fitting the annular seal material S3. On the inner circumference side of the divided plate-shaped member 31, there are multiple (two in this embodiment) inner circumference through holes 31c into which fixing bolts 24C that fix the clamping plate 24A (described later) and the divided plate-shaped member 31 and the retaining member 15 are inserted. On the outer circumference side of the divided plate-shaped member 31, there are multiple (a combination of four and two in this embodiment) outer circumference through holes 31d into which connecting members 33, which consist of bolts and nuts for connecting to the annular projection 30c of the work case 30, are inserted. The multiple outer circumference through holes 31d are two types of concentric holes depending on the dimensions of the work case 30. In addition, a central through hole 31e is formed at the innermost circumference (center) of the divided plate-shaped member 31 through which the shaft member 7 passes.

[0056] As shown in Figure 2, the divided plate-shaped member 31 of the work case 30 is provided with a descent restrictor 24 that prevents the shaft member 7, to which the locking mechanism 4, sealing mechanism 5, and holding member 15 are attached, from descending under its own weight. The descent restrictor 24 consists of a pair of clamping plates 24A capable of clamping and fixing the inner cylinder shaft 7A and the outer cylinder shaft 7B, a hexagon socket head bolt 24B that tightens and fixes both clamping plates 24A in a clamping state, and a fixing bolt 24C that fixes the clamping plates 24A, the divided plate-shaped member 31, and the holding member 15.

[0057] As shown in Figures 5 and 6, the work case 30 in this embodiment has a first divided case 30A, a second divided case 30B, a first plate-shaped member 31A, and a second plate-shaped member 31B. The first divided case 30A and the second divided case 30B are connected by a plurality of bolts B (eight in this embodiment), and the divided plate-shaped member 31, which is formed by integrating the first plate-shaped member 31A and the second plate-shaped member 31B with a plurality of fastening members 32 (four in this embodiment), is connected to the first divided case 30A and the second divided case 30B with a plurality of connecting members 33 (four in this embodiment). Furthermore, the cut surfaces of the first divided case 30A and the second divided case 30B and the cut surfaces of the first plate-shaped member 31A and the second plate-shaped member 31B are perpendicular to each other. As a result, the block portions 31Ab and 31Bb of the divided plate-shaped member 31 can be positioned without interfering with the lowering restrictor 24.

[0058] Next, a method for blocking a branch channel, including a method for removing the branch channel blocking device X, will be explained using Figures 9 to 16.

[0059] The branch channel closure method includes, as shown in Figure 9, a temporary closure step of closing the channel of the branch pipe section 2 with an existing gate valve 3; a removal step of removing the existing air valve 6 (existing fluid equipment) connected to the branch pipe section 2 after the temporary closure step; as shown in Figure 10, an installation step of installing a work case 30 in which a shaft member 7 to which a locking mechanism 4 and a sealing mechanism 5 are connected is inserted in a sealed state into the branch pipe section 2 from which the air valve 6 has been removed; as shown in Figure 11, a locking step of opening the gate valve 3 and then operating the shaft member 7 to lock the locking mechanism 4 to the periphery of the branch channel opening (connection portion 2a) of the branch pipe section 2; and a closure step of supplying air inside the elastic member 5C to close the channel of the branch pipe section 2.

[0060] Furthermore, the branch channel closure method includes, as shown in Figure 12, a first removal step in which the work case 30 is removed after the closure step while the branch channel closure device X remains in place; as shown in Figure 13, a first installation step in which the repair valve 8 (new fluid equipment) and the work case 30 are installed in the branch pipe section 2 after the first removal step; as shown in Figure 14, a second removal step in which the flow path of the branch pipe section 2 is closed by the repair valve 8 and the branch channel closure device X is removed after the first installation step; and as shown in Figure 15, a second installation step in which the air valve 9 (new fluid equipment) is installed on the repair valve 8.

[0061] The method for removing the branch channel blocking device X in this embodiment includes a blocking step and a first removal step, the first removal step including a case removal step in which, after the blocking step, the work case 30 connected to the gate valve 3 is removed in a direction intersecting the axis Y direction, and a gate valve removal step in which, after the case removal step, the third divided inner cylinder shaft 7A3 and the third divided outer cylinder shaft 7B3 (an example of the second axis member) are removed and then the gate valve 3 is removed along the axis Y direction.

[0062] As shown in Figure 9, in the temporary closure process, the valve body 3c of the existing gate valve 3 is moved to close the flow path of the branch pipe section 2. If the valve body 3c is stuck and cannot be moved due to deterioration of the existing gate valve 3, a tightening ring (not shown) is attached to the outer surface of both connecting flange sections 2c and 3a. This tightening ring has a pair of roughly semi-circular tightening segmented rings (not shown) and a gate plate valve (not shown). After loosening the bolts and nuts of both connecting flange sections 2c and 3a, the pair of tightening segmented rings are pulled together and fixed with bolts and nuts. Then, the valve plate of the gate plate valve is inserted between both connecting flange sections 2c and 3a to close the flow path of the branch pipe section 2.

[0063] After blocking the flow path of the branch pipe section 2, the existing air valve 6 is removed in the removal process. Although not shown in the diagram, after the temporary blocking process, a work case 30 equipped with a cleaning machine is attached to the connecting flange section 3b downstream of the gate valve 3, and the inner surface of the branch pipe section 2 is cleaned. At this time, if the valve body 3c of the existing gate valve 3 is stuck and cannot be moved, a work gate valve (not shown) is installed between the work case 30 and the gate valve 3.

[0064] Next, as shown in Figure 10, in the installation process, the connecting flange portion 30a of the work case 30 is fixed to the connecting flange portion 3b on the downstream side of the gate valve 3 with bolts and nuts. The locking mechanism 4 and the sealing mechanism 5 are housed inside the work case 30, and the shaft member 7 (outer cylinder shaft 7B) that supports the locking mechanism 4 and the sealing mechanism 5 is held by the holding member 15 and clamped and fixed by the lowering restrictor 24. At this time, as shown in the left diagram of Figure 8, the first water-stopping fitting 5Ab abuts against the first disc-shaped member 5Aa and the second water-stopping fitting 5Bb abuts against the second disc-shaped member 5Ba, and the expansion portion 63 of the sealing mechanism 5 is housed upright inside the work case 30. In this installation process, the first divided case 30A and the second divided case 30B and the first plate-shaped member 31A and the second plate-shaped member 31B that constitute the work case 30 may be assembled on site, or a pre-assembled work case 30 as described above may be used.

[0065] Next, as shown in Figure 11, the gate valve 3 is opened and the hex socket head bolt 24B of the lowering restraint 24 is loosened. Then, the shaft member 7 is operated manually or by a lowering device such as a lever block (registered trademark) not shown, to lower the locking mechanism 4 and the sealing mechanism 5. When the locking mechanism 4 and the sealing mechanism 5 have lowered to the point where the upper ends of the second divided inner shaft 7A2 and the second divided outer shaft 7B2 (an example of the first shaft member) are positioned on the divided plate-shaped member 31 of the work case 30, the third divided inner shaft 7A3 and the third divided outer shaft 7B3 (an example of the second shaft member) are connected to the second divided inner shaft 7A2 and the second divided outer shaft 7B2. Next, the third divided inner shaft 7A3 and the third divided outer shaft 7B3 are operated manually or otherwise until the locking mechanism 4 is positioned on the periphery (connection portion 2a) of the branch channel opening of the branch pipe section 2. Then, the fourth divided inner shaft 7A4 (an example of a second shaft member), to which an operating nut 10A is screwed onto the male threaded portion 7Aa at the downstream end (upper end), and the fourth divided outer shaft 7B4 (an example of a second shaft member), to which a coupler 13a and bearing 7Bb are attached, are connected to the third divided inner shaft 7A3 and the third divided outer shaft 7B3. In this way, even when the height of the working space up to the ceiling wall R of the structure is limited, work efficiency can be increased by using shaft members 7 that are divided into multiple parts to correspond to the limited height of this working space.

[0066] Next, in the locking process, the inner cylinder shaft 7A is pulled up by rotating the operating nut 10A while sliding it against the bearing 7Bb located on the downstream end face (upper surface) of the fourth divided outer cylinder shaft 7B4, thereby locking the locking mechanism 4 to the periphery of the branch flow channel opening (connection portion 2a) of the branch pipe section 2. More specifically, by moving the inner cylinder shaft 7A downstream (upward), the locking link 44 of the locking mechanism 4 is set to an expanded position and engages with the periphery of the branch flow channel opening on the inner circumferential surface of the branch pipe section 2. As the operating nut 10A becomes unable to rotate, the locking of the locking mechanism 4 is completed, and the locking state of the locking mechanism 4 is prevented from being released by the operating nut 10A and the male threaded portion 7Aa. Next, the hexagon socket head bolt 24B of the lowering restrictor 24 is tightened to clamp and fix the shaft member 7 (outer cylinder shaft 7B). As a result, the downward restraining device 24 prevents the shaft member 7 (outer cylindrical shaft 7B) from falling due to its own weight.

[0067] Next, in the occlusion process, air is supplied to the inside of the elastic member 5C to occlude the flow path of the branch pipe section 2. More specifically, air is supplied from the fluid supply mechanism 13 to the fluid flow path F in the gap between the outer cylinder shaft 7B and the inner cylinder shaft 7A via the coupler 13a, and air is introduced into the fluid introduction space A from the fluid inlet 51 (see also the right diagram in Figure 8). As a result, the expansion part 63 expands radially outward in response to the fluid pressure, making close contact with the inner surface of the branch pipe section 2 and occluding the flow path of the branch pipe section 2. Thus, in the occlusion process of this embodiment, a large driving force such as a hydraulic jack is not required, and it is only necessary to supply air from the fluid inlet 51, thus improving work efficiency. Moreover, if the seal mechanism 5 is composed of an elastic member 5C that expands due to fluid pressure, the amount of expansion can be freely changed simply by changing the fluid pressure, and it is possible to accommodate branch pipe sections 2 of any inner diameter without increasing the axial dimensions of the device.

[0068] Next, as shown in Figure 12, in the first removal step, the work case 30 and the gate valve 3 are removed while leaving a portion of the branch channel blocking device X in place. More specifically, the first removal step includes a case removal step in which the work case 30 connected to the gate valve 3 is removed in a direction intersecting the axis Y direction after the blocking step, and a gate valve removal step in which the third divided inner cylinder shaft 7A3 and the third divided outer cylinder shaft 7B3 are removed after the case removal step, and then the gate valve 3 is removed along the axis Y direction.

[0069] In the case removal process, the fixing bolts 24C of the divided plate-shaped member 31 of the work case 30 are removed to release the fixing between the divided plate-shaped member 31 and the holding member 15, and the fastening member 32 connecting the first plate-shaped member 31A and the second plate-shaped member 31B is removed to remove the divided plate-shaped member 31. Then, the bolt B connecting the first divided case 30A and the second divided case 30B is removed, and the work case 30 is removed from a direction intersecting the axis Y direction. In this way, since the work case 30 is removed to the side of the shaft member 7, it is not necessary to remove the work case 30 along the axis Y direction from the upper end of the shaft member 7, and the work case 30 can be removed without interfering with obstacles even in places where there are obstacles in the upper part of the work space such as ceiling walls R.

[0070] Next, in the gate valve removal process, the fourth divided inner shaft 7A4 and the fourth divided outer shaft 7B4 (an example of the second shaft member), the third divided inner shaft 7A3 and the third divided outer shaft 7B3 (an example of the second shaft member) are removed in order. At this time, it is preferable to remove the shaft members 7 in order using a jig (not shown) that applies a downward force to the outer shaft 7B to prevent the sealing mechanism 5 from moving due to the fluid pressure of the tap water in the water pipe 1. Next, the bolts and nuts that fix the connecting flange portion 2c of the branch pipe section 2 and the connecting flange portion 3a on the upstream side of the gate valve 3 are removed, and the gate valve 3 is removed along the axis Y direction. At this time, by locking the locking mechanism 4 to the connection portion 2a between the branch pipe section 2 and the water pipe 1, upward movement of the shaft member 7 (inner shaft 7A) due to fluid pressure is prevented, and downward movement of the shaft member 7 is prevented by supplying air to the sealing mechanism 5 and blocking the flow path of the branch pipe section 2. As the shaft member 7 is divided in this way, the gate valve 3 can be removed without interfering with any obstacles by removing at least the fourth divided inner shaft 7A4 and the fourth divided outer shaft 7B4. Although not shown in the figures, it is preferable to attach the release prevention mechanism 10 to the upper ends of the second divided inner shaft 7A2 and the second divided outer shaft 7B2.

[0071] As shown in Figure 16, it is preferable to connect the divided plate-shaped member 31 to the connecting flange portion 2c of the branch pipe section 2 while the first divided outer cylinder shaft 7B1 and the first divided outer cylinder shaft 7B1 are held between the retaining member 15 and the divided plate-shaped member 31 that were removed in the first removal process, thereby providing a downward restricting device 24 to prevent the shaft member 7 from descending under its own weight. The retaining member 15 and the divided plate-shaped member 31 function as upward restricting devices that restrict the movement of the seal mechanism 5 due to the fluid pressure of the water in the water pipe 1. In this way, since the divided plate-shaped member 31 that is connected to the annular projection 30c is provided separately, after the work case 30 and the gate valve 3 are removed, it becomes possible to hold the shaft member 7 with this divided plate-shaped member 31 so as to cover the opening of the branch pipe section 2, thereby stabilizing the sealing function of the seal mechanism 5.

[0072] Next, as shown in Figure 13, in the first installation step, after the first removal step, the new repair valve 8 is fastened to the branch pipe section 2 with bolts and nuts and installed, and the work case 30 is fastened to the new repair valve 8 with bolts and nuts and installed. In this first installation step, the first divided case 30A and the second divided case 30B and the first plate-shaped member 31A and the second plate-shaped member 31B that constitute the work case 30 may be assembled on site, or a pre-assembled work case 30 may be used. If the work case 30 is assembled on site, after attaching the new repair valve 8 to the branch pipe section 2, the third divided inner cylinder shaft 7A3 and the third divided outer cylinder shaft 7B3 and the fourth divided inner cylinder shaft 7A4 and the fourth divided outer cylinder shaft 7B4 are connected to the second divided inner cylinder shaft 7A2 and the second divided outer cylinder shaft 7B2, and then the work case 30 is assembled, thus improving work efficiency.

[0073] Then, the divided plate-shaped member 31 and the holding member 15 of the work case 30 are fixed with fixing bolts 24C to maintain a sealed state inside the work case 30. Next, the operating nut 10A screwed onto the inner cylinder shaft 7A is loosened, and the inner cylinder shaft 7A is lowered to reduce the diameter of the locking link 44 of the locking mechanism 4, and the introduction of fluid from the fluid inlet 51 is stopped, thereby reducing the fluid pressure acting on the elastic member 5C and reducing the diameter of the elastic member 5C (see also Figure 14). Next, the shaft member 7 is operated manually or otherwise to raise the locking mechanism 4 and the seal mechanism 5. At this time, the shaft member 7 is raised while sequentially releasing the connections of the divided shaft member 7 until the locking mechanism 4 and the seal mechanism 5 are housed inside the work case 30.

[0074] Next, as shown in Figure 14, in the second removal step, with the flow path of the branch pipe section 2 blocked by the repair valve 8, the work case 30 is removed to the side of the shaft member 7, and then the shaft member 7 is removed in order before the locking mechanism 4 and the sealing mechanism 5 are removed. In this second removal step, as in the first removal step described above, the work case 30 is removed to the side of the shaft member 7, so it is not necessary to remove the work case 30 along the axis Y direction from the upper end of the shaft member 7, and even in places where there are obstacles in the upper part of the work space such as ceiling walls R, the work case 30 can be removed without interfering with the obstacles. In addition, in the second removal step, the branch flow path blocking device X may be removed without disassembling the work case 30, with the locking mechanism 4 and the sealing mechanism 5 housed inside the work case 30. Finally, as shown in Figure 15, in the second installation step, the air valve 9 (newly installed fluid equipment) is installed on the repair valve 8, and the replacement of the fluid equipment is completed.

[0075] [Alternative Embodiment] As shown in Figure 17, the work case 30 may have a connecting flange portion 30a connected to the connecting flange portion 3b on the downstream (upper) side of the gate valve 3, a cylindrical body 30b extending from the inner circumference of the connecting flange portion 30a in the axial direction Y of the shaft member 7, and a disc-shaped bottom wall portion 30d extending inward from the end of the cylindrical body 30b opposite to the connecting flange portion 30a. In this case, the shaft member 7 is held in a sealed state by the divided portion of the bottom wall portion 30d. The connecting flange portion 30a and the cylindrical body 30b in this embodiment are the same as in the embodiment described above, so a detailed explanation is omitted. In this embodiment, the holding member 15 is fixed to the bottom wall portion 30d, which is different from the embodiment described above in that the holding member 15 was fixed to the divided plate-shaped member 31. In this embodiment as well, the work case 30 is composed of a first divided case 30A and a second divided case 30B. In this embodiment, the shaft member 7 is held in a sealed state by the divided portion of the bottom wall 30d, thereby making the work case 30 more compact. Other effects are the same as in the embodiment described above.

[0076] [Other embodiments] (1) In the above-described embodiment, the work case 30 is configured in two parts, but the work case 30 may be divided into three or more parts. Also, the shaft member 7 may be divided into a first shaft member and a second shaft member according to the dimension in the Y direction of the axial center of the gate valve 3, and the number of divisions is not particularly limited. (2) The shaft member 7 may also be a two-shaft structure in which an inner cylindrical shaft 7A that operates the locking mechanism 4 and an outer cylindrical shaft 7B that supplies air to the fluid inlet 51 are separated. (3) The locking mechanism 4 is not limited to the above-described form, as long as it can be changed to an expanded diameter position by operating the inner cylinder shaft 7A. (4) In the above-described embodiment, the pair of upper annular members 5A is composed of a first disc-shaped member 5Aa and a first water-stopping fitting 5Ab, and the pair of lower annular members 5B is composed of a second disc-shaped member 5Ba and a second water-stopping fitting 5Bb. Alternatively, the upper annular member 5A or the lower annular member 5B may be composed of an annular member to which the clamped portions 61, 62 of the elastic member 5C are fixed, and either the first water-stopping fitting 5Ab or the second water-stopping fitting 5Bb may be made movable. Even in this case, the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb become a segmented structure that can move relative to each other by screwing in a pull-in bolt 52 or pull-in bolts 53, 55a.

[0077] (5) The first clamped portion 61 and the second clamped portion 62 described above may not be made of an elastic member 5C integrated with the expansion portion 63, but rather the first clamped portion 61 and the second clamped portion 62 made of metal or the like may be connected to the expansion portion 63 as an elastic member 5C. (6) In the above-described embodiment, air was introduced into the seal mechanism 5, but a liquid such as water may also be introduced. (7) Instead of the retaining member 15 described above, the sealing mechanism 5 may be provided with a mechanism for holding the inner cylinder shaft 7A and the outer cylinder shaft 7B. (8) Instead of the release prevention mechanism 10 described above, a separate mechanism for gripping the inner cylinder shaft 7A may be provided. (9) In the embodiments described above, a water pipe 1 through which tap water flows was used, but it may also be a fluid pipe through which liquids other than tap water or gases such as gases flow. [Industrial applicability]

[0078] The present invention can be used for a branch channel blocking device that blocks the flow path of a branched pipe section branched from a fluid pipe, and for a branch channel blocking method using the branch channel blocking device. [Explanation of symbols]

[0079] 1: Water pipe (fluid pipe) 2: Branch pipe section 2a: Connection part 3: Gate valve 4: Locking mechanism 5: Seal mechanism 5C: Elastic member 7: Shaft member 7A1: First divided inner cylinder shaft (first shaft member) 7A2: Second split inner cylinder shaft (first shaft member) 7A3: Third division inner cylinder shaft (second shaft member) 7A4: Fourth division inner cylinder shaft (second shaft member) 7B1: First divided outer cylinder shaft (first shaft member) 7B2: Second split outer cylinder shaft (first shaft member) 7B3: Third-part outer cylinder shaft (second shaft member) 7B4: Fourth division outer cylinder shaft (second shaft member) 30: Work Case 30A: First split case 30Aa: First half-split member 30Ab: First protrusion 30Ab2: mating surface 30Ac: First connecting flange section 30B: Second split case 30Ba: Second half-split member 30Bb:Second protrusion 30Bb2: mating surface 30Bc: Second connecting flange section 30a: Connecting flange section 30a: Flange section 30b: Cylindrical body 30c: Annular protrusion 30d:Bottom wall part 31: Divided plate-shaped member S1: First sealing member (sealing member) S2: Second sealing member (sealing member) X: Branch channel blocking device Y: Axial center

Claims

1. A branch channel blocking device that blocks the flow path of a branched pipe section that branches off from a fluid pipe, A gate valve that is detachably connected to the branch pipe section, A work case that is detachably connected to the gate valve, A locking mechanism that engages with the connection portion between the branch pipe section and the fluid pipe, A sealing mechanism having an elastic member capable of blocking the flow path of the branched pipe section, The shaft member comprises a first shaft member that supports the locking mechanism and the sealing mechanism, and a second shaft member connected to the first shaft member, The aforementioned work case is a divided body that is divided along the axial direction of the shaft member, and the branch channel blocking device holds the shaft member in a sealed state between the divided portions of the divided body.

2. The aforementioned work case includes the first division case and the second division case, The first split case comprises a first split member shaped like a half, a pair of first protrusions projecting radially outward from both circumferential ends of the first split member, and a first connecting flange portion connected to the flange of the gate valve. The second split case comprises a halved second split member, a pair of second protrusions projecting radially outward from both circumferential ends of the second split member, and a second connecting flange portion connected to the flange. The branch channel blocking device according to claim 1, wherein a sealing member is continuously arranged on the mating surface of the first protrusion and the second protrusion, and on the surface of the first connecting flange and the second connecting flange facing the flange.

3. The work case has a connecting flange portion connected to the flange of the gate valve, a cylindrical body extending in the axial direction from the inner circumference of the connecting flange portion, and a bottom wall portion extending inward from the end of the cylindrical body opposite to the connecting flange portion. The branch channel blocking device according to claim 1 or 2, wherein the shaft member is held in a sealed state between the divided portion of the bottom wall.

4. The work case comprises a connecting flange portion connected to the flange of the gate valve, a cylindrical body extending in the axial direction from the inner circumference of the connecting flange portion, an annular projection portion projecting outward in an annular shape from the end of the cylindrical body opposite to the connecting flange portion, and a divided plate-like member connected to the annular projection portion. The branch channel blocking device according to claim 1 or 2, wherein the shaft member is held in a sealed state between the divided portion of the divided plate-shaped member.

5. A method for removing a branch channel blocking device according to any one of claims 1 to 4, A blocking step in which the sealing mechanism closes the flow path of the branch pipe section with the sealing mechanism while the locking mechanism is locked to the connecting portion, After the aforementioned blocking process, a case removal process is performed in which the work case connected to the gate valve is removed in a direction intersecting the axial direction, A method for removing a branch channel blocking device, comprising: a gate valve removal step, after the case removal step, removing the second shaft member and then removing the gate valve along the axial direction.

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