Branch flow path closing device and branch flow path closing method

Abstract

To provide a compact branch flow path closing device and a branch flow path closing method with high work efficiency.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 locking mechanism 4 locked to a connecting portion between the branch pipe part and the fluid pipe; a seal mechanism 5 having an elastic member 5C capable of closing the flow path of the branch pipe; and a shaft member 7 that supports the locking mechanism 4 and the seal mechanism 5. The seal mechanism 5 has a fluid inflow part 51 that allows fluid to flow into the elastic member 5C, a first support part 5Ab that supports one end of the elastic member 5C, and a second support part 5Bb that supports the other end of the elastic member 5C. The first support part 5Ab and the second support part 5Bb are structured to be divided so as to be relatively movable.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a branch flow passage closing device that closes a flow passage of a branch pipe portion branched off from a fluid pipe, and a branch flow passage closing method using the branch flow passage closing device. [Background technology]

[0002] Conventionally, a branch flow path blocking device has been known that is used when existing fluid equipment consisting of an on-off valve (repair valve, etc.) installed at a branch pipe section of a fluid pipe (water pipe, etc.) or an air valve or fire hydrant installed above an on-off valve is replaced with new fluid equipment (fluid equipment is updated) because the existing fluid equipment has exceeded its useful life, etc. (see, for example, Patent Document 1).

[0003] The branch flow path closing device described in Patent Document 1 includes an outer operating shaft, an inner operating shaft inserted into the outer operating shaft, a retaining locking means that is locked to the connection part between the branch pipe section and the fluid pipe by operating the outer operating shaft and the inner operating shaft, and a sealant that closes the flow path of the branch pipe section by elastically deforming in the radial expansion direction by moving the outer operating shaft relative to the inner operating shaft. The outer operating shaft and the inner operating shaft are divided so that they can be connected by extension, which can improve work efficiency even in places with small working space. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-38227 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the branch flow path closing device described in Patent Document 1 requires a large driving force from a hydraulic jack attached to the upper part of the work case when the outer operating shaft is moved relative to the inner operating shaft to elastically deform the sealing material in the diameter expansion direction, and there is room for improvement in terms of improving work efficiency. Also, since the sealing material is elastically deformed in the diameter expansion direction to close the flow path of the branch pipe section, it is necessary to ensure an axial dimension equal to the difference between the uncompressed and compressed states of the sealing material, which increases the size, and it is necessary to adjust the radial dimension of the sealing material to match the inner diameter of the branch pipe section, which reduces the degree of freedom in applying the branch flow path closing device to the branch pipe section.

[0006] Therefore, there is a demand for a branch passage closing device and a branch passage closing method that are compact and have high work efficiency. [Means for solving the problem]

[0007] A characteristic configuration of the branch flow path closing device according to the present invention is a branch flow path closing device that closes a flow path of a branch pipe section branched off from a fluid pipe, and includes a locking mechanism that is locked to a connection portion between the branch pipe section and the fluid pipe, a sealing mechanism having an elastic member capable of closing the flow path of the branch pipe section, and a shaft member that supports the locking mechanism and the sealing mechanism, and the sealing mechanism has a fluid inflow section that allows fluid to flow into the elastic member, a first support section that supports one end of the elastic member, and a second support section that supports the other end of the elastic member, and the first support section and the second support section have a divided structure that are relatively movable. a tensile force acting along an axial direction of the shaft member acts on the elastic member when the first support portion and the second support portion are separated from each other. It's at the point.

[0008] In this configuration, the locking mechanism that is locked to the connection between the branch pipe section and the fluid pipe prevents the shaft member from moving upward due to fluid pressure, and the sealing mechanism that closes the flow path of the branch pipe section prevents the shaft member from moving downward. As a result, by attaching this branch flow path closing device to the branch pipe section, it is possible to replace fluid equipment while preventing fluid from flowing out of the branch pipe section.

[0009] The sealing mechanism in this configuration has a fluid inlet portion that allows fluid to flow into the elastic member, and the fluid flowing in from the fluid inlet portion causes the elastic member to expand and block the flow path of the branch pipe portion. In other words, unlike the conventional method, the sealing material is not compressed and elastically deformed in the direction of diameter expansion, but is expanded by fluid pressure. As a result, no large driving force such as a hydraulic jack is required, and it is only necessary to supply fluid from the fluid inlet portion, which improves work efficiency. Moreover, if the sealing mechanism is configured with an elastic member that expands with fluid pressure, it is possible to freely change the amount of expansion simply by changing the fluid pressure, and it is possible to accommodate branch pipe portions of any inner diameter without increasing the axial dimension of the device.

[0010] Moreover, since the sealing mechanism in this configuration has a divided structure in which the first support part and the second support part that support the elastic member are movable relative to each other, if the first support part and the second support part are separated while supporting the elastic member and tension is applied to the elastic member, it is possible to prevent deformation of the elastic member before expansion. As a result, when the elastic member is expanded by inflowing fluid from the fluid inlet part, it is possible to expand the elastic member evenly, and the flow path of the branch pipe part can be reliably closed. In this way, a compact branch flow path closing device with high work efficiency has been provided.

[0011] Another characteristic configuration is that the sealing mechanism further includes a first annular member connected to the shaft member, and a second annular member located closer to the fluid pipe than the first annular member, and the elastic member has a first clamped portion clamped between the first annular member and the first support portion, a second clamped portion clamped between the second annular member and the second support portion, and an expansion portion connecting the first clamped portion and the second clamped portion, and expanding when fluid flows in from the fluid inflow portion.

[0012] In this configuration, both ends of the elastic member (the first clamped portion and the second clamped portion) are clamped between the first annular member and the first support portion, and the second annular member and the second support portion, so that the posture of the expansion portion when it expands can be stabilized.

[0013] Another characteristic configuration is that the shaft member is a single-shaft structure including an inner tube shaft that operates the locking mechanism and an outer tube shaft into which the inner tube shaft is inserted coaxially with the inner tube shaft, and a fluid flow path communicating with the fluid inlet portion is formed in the gap between the inner tube shaft and the outer tube shaft.

[0014] With this configuration, a single-shaft structure in which a fluid flow passage that communicates with the fluid inlet is formed in the gap between the inner and outer cylinder shafts allows the fluid inlet to be located near the center of the seal mechanism, allowing the elastic member to expand evenly due to fluid pressure. Moreover, when the locking mechanism is operated, the inner cylinder shaft moves while being guided by the outer cylinder shaft, preventing the inner cylinder shaft from tilting and improving durability.

[0015] Another characteristic feature is that the locking mechanism is configured so that its diameter can be expanded by rotating a nut.

[0016] As in the present configuration, expanding the diameter of the locking mechanism by operating the nut provides excellent operability, and it is easy to confirm that the locking mechanism has been completely locked when the nut becomes unable to rotate.

[0017] A characteristic configuration of the branch flow path blocking method of the present invention is a branch flow path blocking method using any of the branch flow path blocking devices described above, and includes a temporary blocking step of blocking the flow path of the branch pipe section with an operating valve, a removal step of removing existing fluid equipment connected to the branch pipe section after the temporary blocking step, an installation step of mounting a work case in which the axial member having the locking mechanism and the sealing mechanism is inserted in a sealed state to the branch pipe section from which the existing fluid equipment has been removed, a locking step of operating the axial member to lock the locking mechanism to the connection portion after opening the work valve, and a closing step of supplying fluid into the inside of the elastic member to block the flow path of the branch pipe section.

[0018] In this method, the locking mechanism is engaged at the connection between the branch pipe section and the fluid pipe to prevent the shaft member from moving upward due to fluid pressure, and the sealing mechanism is supplied with fluid to close the flow path of the branch pipe section to prevent the shaft member from moving downward. As a result, after the branch pipe section is fitted with the branch flow path closing device and the closing step is performed, the fluid equipment can be easily replaced.

[0019] Furthermore, the sealing mechanism in this method does not compress the sealing material to elastically deform in the radial direction, but expands the elastic member with fluid pressure. As a result, it is possible to improve work efficiency by simply supplying fluid to the sealing mechanism without requiring a large driving force such as a hydraulic jack. Moreover, if the sealing mechanism is made of an elastic member that expands with fluid pressure, the amount of expansion can be freely changed simply by changing the fluid pressure, and the device can be adapted to branch pipes of any inner diameter without increasing the axial dimension. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a side view showing an existing fluid device. [Diagram 2] 1 is a side cross-sectional view showing a branch flow path closing device according to an embodiment of the present invention. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] 10A to 10C are cross-sectional views showing a procedure for correcting the posture of the elastic member. [Figure 6] 5A to 5C are side cross-sectional views showing an operation procedure of the branch flow path closing device. [Figure 7] 11 is a side view showing a temporary closing step and a removal step. FIG. [Figure 8] FIG. [Figure 9] 11A to 11C are side cross-sectional views showing a locking step and a closing step. [Figure 10] FIG. 11 is a side cross-sectional view showing a first removal step. [Figure 11] FIG. 4 is a side cross-sectional view showing a first installation step. [Figure 12] FIG. 11 is a partial cross-sectional side view showing a second removal step. [Figure 13] FIG. 11 is a side view showing a second installation step. [Figure 14] FIG. 11 is a side view showing a temporary closing step according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of a branch flow path closing device and a branch flow path closing method according to the present invention will be described with reference to the drawings. In this embodiment, an example will be described in which a branch flow path closing device is used to update air valves and gate valves that constitute fluidic equipment. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the gist of the present invention. In the following description, the direction of gravity may be referred to as down, and the direction opposite to the direction of gravity as up.

[0022] As shown in Fig. 1, a connecting flange 3a on the upstream side (lower side) of a gate valve 3 (an example of an existing fluid device) is fastened in a watertight manner by bolts and nuts to a connecting flange 2c of a branch pipe section 2 formed in the middle of a water pipe 1 (an example of a fluid pipe) and protruding radially outward. Also, a connecting flange 6a of an air valve 6 (an example of an existing fluid device) is fastened in a watertight manner by bolts and nuts to a connecting flange 3b on the downstream side (upper side) of the gate valve 3.

[0023] In this embodiment, while maintaining the flow of clean water in the water pipe 1 without any water interruption, the existing check valve 3 and air valve 6 are replaced with a new repair valve 8 and air valve 9 (new fluid equipment) using a branch flow path blocking device X described below when they have reached the set service life or due to reasons such as leakage or malfunction due to deterioration (see Figure 13).

[0024] FIG. 2 shows a side cross-sectional view of the branch flow path closing device X. The branch flow path closing device X closes the flow path of the branch pipe section 2 branched from the water pipe 1 described above (see also FIG. 9). The branch flow path closing device X includes a locking mechanism 4 that is locked to a connection portion 2a between the branch pipe section 2 and the water pipe 1, a sealing mechanism 5 (see also FIG. 9) that can close the flow path of the branch pipe section 2, an axial member 7 that supports the locking mechanism 4 and the sealing mechanism 5 and has a single axial structure of an inner cylindrical shaft 7A and an outer cylindrical shaft 7B, and a holding member 15 that holds the axial member 7. Although details will be described later, the sealing mechanism 5 in this embodiment has a fluid inlet section 51 into which air (an example of a fluid) flows, and expands radially outward when air flows in from the fluid inlet section 51 to close the flow path of the branch pipe section 2.

[0025] The locking mechanism 4 includes a plate-shaped member 41 provided at the upstream end (lower end) to which the tip of the inner tube shaft 7A abuts to restrict movement, a guide member 42 to which the plate-shaped member 41 is fixed and into which the inner tube shaft 7A is movably inserted, a spring 43 arranged inside the guide member 42, and multiple locking links 44 (two in the circumferential direction in this embodiment) connected to the radially outer side of the spring 43 on the outside of the guide member 42 and capable of swinging freely.

[0026] The plate-like member 41 is fixed to the upstream end face (lower surface) of the guide member 42 (a rod-like member 42a described later). The tip of the inner cylindrical shaft 7A, which has moved due to the biasing force of the spring 43, comes into contact with the downstream end face (upper surface) of the plate-like member 41, thereby restricting the downward movement of the inner cylindrical shaft 7A. One end of a pair of upstream locking links 44 is pivotally connected to both left and right ends of the plate-like member 41 so as to be freely swingable.

[0027] The guide member 42 has a plurality of rod-shaped members 42a (four in this embodiment) each having one end fixed to a tip plate 55 (described later) and the other end fixed to the plate-shaped member 41, and a slide member 42b that is axially slidable while being supported between the rod-shaped members 42a. A part of the movable inner cylindrical shaft 7A and a spring 43 arranged on the outer circumferential side of the inner cylindrical shaft 7A are housed inside the rod-shaped members 42a. The other ends of a pair of downstream locking links 44 are pivotally connected to both left and right ends of the slide member 42b so as to be swingable.

[0028] 6, the locking link 44 can extend into the expanded diameter position in conjunction with the movement of the inner cylindrical shaft 7A downstream (upward). The locking link 44 in the expanded diameter position engages with the inner circumferential wall surface of the branch pipe section 2 upstream of the location where the branch flow path is blocked by the sealing mechanism 5, that is, the periphery of the branch flow path opening (connection portion 2a) on the inner circumferential surface of the branch pipe section 2. At this time, the tip of the inner cylindrical shaft 7A is maintained separated from the plate-like member 41 by the release prevention mechanism 10 described later.

[0029] As shown in Figures 2 and 3, the sealing mechanism 5 has a pair of upper annular members 5A, a pair of lower annular members 5B, a hollow tubular member 54, a tip plate 55, and an elastic member 5C arranged between the upper annular member 5A and the lower annular member 5B.

[0030] The pair of upper annular members 5A is composed of a first disk-shaped member 5Aa (an example of a first annular member) and a first water-stop fitting 5Ab (an example of a first support part) connected to the first disk-shaped member 5Aa by a plurality of (eight in this embodiment) hexagon socket head bolts or the like. The pair of lower annular members 5B is composed of a second disk-shaped member 5Ba (an example of a second annular member) and a second water-stop fitting 5Bb (an example of a second support part) connected to the second disk-shaped member 5Ba by a plurality of (eight in this embodiment) hexagon socket head bolts 53, 55a. The first water-stop fitting 5Ab and the second water-stop fitting 5Bb in this embodiment have a split structure that can move relative to each other by screwing together the pull bolts 52 and / or the pull bolts 53, 55a.

[0031] 4, the first disk-shaped member 5Aa is integrally formed with a base 56a having a concave upstream end surface (lower surface) and an extension 56b extending from the base 56a to the downstream side (upper side). The base 56a has a plurality of (eight in this embodiment) through holes 56a1 at equal intervals in the circumferential direction, into which the clamping bolts 52 are inserted, in an annular portion adjacent to the extension 56b. A pair of inner peripheral seal members sa attached to the inner peripheral surface of the holding member 15 abuts against the outer peripheral surface of the extension 56b, and the inner cylinder shaft 7A faces the inner peripheral surface of the extension 56b. A male thread 56b1 is formed on the outer peripheral surface of the downstream end (upper end) of the extension 56b, and a female thread 7Ba formed on the inner peripheral surface of the upstream end (lower end) of the outer cylinder shaft 7B is screwed into the male thread 56b1, thereby connecting the first disk-shaped member 5Aa and the outer cylinder shaft 7B. In other words, the first disk-shaped member 5Aa is supported by the outer cylinder shaft 7B. In addition, a seal groove 56b2 in which an O-ring sb is attached is formed upstream (lower) of the male thread 56b1 on the outer peripheral surface of the downstream end (upper end) of the extension 56b, and a tapered surface 56b5 for compressing the O-ring sh is formed downstream (upper) of the male thread 56b1.

[0032] A female screw portion 56b3 is formed on the inner peripheral surface of the upstream end (lower end) of the extension portion 56b, and is screwed into a male screw portion 54a formed on the outer peripheral surface of the downstream end (upper end) of the hollow cylindrical member 54, thereby connecting the first disk-shaped member 5Aa and the hollow cylindrical member 54. That is, the hollow cylindrical member 54 is also supported by the outer cylindrical shaft 7B via the first disk-shaped member 5Aa. In addition, a seal groove 56b4 in which an O-ring sc is attached is formed on the inner peripheral surface of the upstream end (lower end) of the extension portion 56b downstream (upper) of the female screw portion 56b3. When the first disk-shaped member 5Aa and the hollow cylindrical member 54 are connected, the O-ring sc comes into contact with a tapered surface 54a1 formed on the downstream end (upper end) of the male screw portion 54a of the hollow cylindrical member 54 and is compressed.

[0033] The first water-stop fitting 5Ab is formed in a cup shape, and is integral with a disk base 57a and a cylindrical portion 57b extending from the outermost side of the disk base 57a to the upstream side (lower side). The disk base 57a has an insertion hole 57a1 through which the hollow tubular member 54 is inserted, and a first step portion 57a2 with which one end of the elastic member 5C engages is formed on the outermost side. A seal groove 57a3 in which an O-ring sd is fitted is formed on the outer periphery side adjacent to the insertion hole 57a1 of the disk base 57a, and a plurality of (eight in this embodiment) female screw holes 57a4 into which the draw bolt 52 is screwed are formed at equal intervals in the circumferential direction on the further outer periphery side of this seal groove 57a3. The cylindrical portion 57b is adjacent to the outside of the second water-stop fitting 5Bb, and serves as an outer cylinder into which the second water-stop fitting 5Bb is inserted.

[0034] The downstream end surface (upper surface) of the second disk-shaped member 5Ba is formed in a concave shape. The second disk-shaped member 5Ba has an insertion hole 58a through which the hollow cylinder member 54 is inserted at the center, and a plurality of (eight in this embodiment) through holes 58b through which the clamping bolts 53, 55a, such as hexagonal socket bolts, are inserted are formed at equal intervals in the circumferential direction on the outer circumferential side of the insertion hole 58a. The inner circumferential surface of the insertion hole 58a has a seal groove 58a1 in which an O-ring sj ​​is fitted, and a locking recess 58a2 in which the hollow cylinder member 54 is locked, formed upstream (lower) of the seal groove 58a1. That is, the second disk-shaped member 5Ba is also supported by the outer cylinder shaft 7B via the first disk-shaped member 5Aa and the hollow cylinder member 54.

[0035] The second watertight fitting 5Bb has an insertion hole 59a formed through the center into which the hollow tubular member 54 is inserted, and a second step 59b into which the other end of the elastic member 5C engages is formed on the outermost side. A seal groove 59c into which an O-ring sf is attached is formed on the outer periphery side adjacent to the insertion hole 59a, and a plurality of (eight in this embodiment) female screw holes 59d into which the draw bolts 53, 55a are screwed are formed at equal intervals in the circumferential direction on the further outer periphery side of this seal groove 59c. The second watertight fitting 5Bb is adjacent to the inside of the cylindrical portion 57b of the first watertight fitting 5Ab, and serves as an inner cylinder into which the cylindrical portion 57b is inserted.

[0036] The pair of upper annular members 5A and the pair of lower annular members 5B are fitted onto the hollow tubular member 54, and the inner cylinder shaft 7A is fitted into the hollow tubular member 54. A plurality of through holes are formed near the axial center of the hollow tubular member 54 as a fluid inlet portion 51 communicating with the fluid introduction space A for expanding the elastic member 5C. The hollow tubular member 54 is also formed at one end with a male thread portion 54a that screws into a female thread portion 56b3 formed on the extension portion 56b of the first disk-shaped member 5Aa, and at the other end with an annular protrusion portion 54b that engages with a locking recess 58a2 formed on the second disk-shaped member 5Ba. The hollow tubular member 54 is inserted into the first watertight fitting 5Ab and the pair of lower annular members 5B to engage the annular protrusion 54b and the locking recess 58a2, and then the hollow tubular member 54 is screwed into the first disk-shaped member 5Aa, thereby positioning the first disk-shaped member 5Aa and the second disk-shaped member 5Ba. In addition, the hollow tubular member 54 is prevented from falling off by the tip plate 55 fixed to the second disk-shaped member 5Ba by a plurality of (four in this embodiment) draw bolts 55a formed of hexagon socket head bolts or the like.

[0037] The tip plate 55 has an insertion hole 55b formed in the center, into which the inner cylinder shaft 7A is inserted, and a plurality of (four in this embodiment) through holes 55c for accommodating the head of the clamp bolt 53 and a plurality of (four in this embodiment) through holes (not shown) into which the male thread of the clamp bolt 55a is inserted are arranged alternately in the circumferential direction. The rod-shaped member 42a of the guide member 42 is fixed to the upstream end face (lower face) of the tip plate 55 with a screw (see also FIG. 2), and a seal groove 55d in which an O-ring sg is fitted is formed between the insertion hole 55b and the through hole 55c in the downstream end face (upper face) of the tip plate 55. A seal groove 55e in which an outer circumferential seal member si is fitted is formed in the inner circumferential surface of the insertion hole 55b, and this outer circumferential seal member si is in close contact with the inner cylinder shaft 7A.

[0038] The elastic member 5C is made of a synthetic rubber having excellent durability, such as ethylene propylene diene rubber (EPDM), and has a first clamped portion 61 clamped between a pair of upper annular members 5A, a second clamped portion 62 clamped 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.

[0039] The first held portion 61 is bent inward from the expanding portion 63 to have an L-shaped cross section, and similarly, the second held portion 62 is bent inward from the expanding portion 63 to have an L-shaped cross section. By engaging the first held portion 61 with the first stepped portion 57a2 of the first water-stopping fitting 5Ab and engaging the second held 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 has a bent and deformed shape in its natural state, and becomes an upright shape by further tightening the pull bolt 52 and / or the pull bolts 53, 55a to separate the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb.

[0040] 5 shows a procedure for correcting the posture of the elastic member 5C. As shown in the left diagram of the figure, 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, and the hollow tubular member 54 is attached inside the pair of upper annular members 5A and the pair of lower annular members 5B, and temporarily fastened with the clamping bolt 52 and the clamping bolts 53, 55a. In this state, the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb are close to each other, and the expanding portion 63 is bent and deformed. Next, as shown in the right diagram of the figure, by further tightening the clamp bolt 52 and the clamp bolts 53, 55a, the first water-stopping fitting 5Ab comes into contact with the first disk-shaped member 5Aa and the second water-stopping fitting 5Bb comes into contact with the second disk-shaped member 5Ba, and the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb are separated from each other. As a result, a tensile force is applied to the expanding portion 63, and the expanding portion 63 becomes upright. With this configuration, the sealed space surrounded by the hollow tubular member 54, the first water-stopping fitting 5Ab, and the second water-stopping fitting 5Bb becomes the fluid introduction space A.

[0041] As shown in the right diagram of FIG. 6, the expansion section 63 receives fluid pressure and expands radially outward due to air introduced from the outer cylinder shaft 7B through the fluid inlet section 51 into the fluid introduction space A. In this way, if the first water-stop fitting 5Ab and the second water-stop fitting 5Bb are separated from each other while the elastic member 5C is supported, and tension is applied 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 section 51, the elastic member 5C can be expanded evenly, and the flow path of the branch pipe section 2 can be reliably blocked. 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.

[0042] Returning to FIG. 2, the inner cylindrical shaft 7A is composed of a solid rod-shaped member that penetrates the center of the holding member 15 fixed to the top plate portion 30b of the work case 30 in a watertight state in the axial direction. Since the height of the work space from the upper surface of the air valve 6 to the ceiling wall R of the structure is limited, the inner cylindrical shaft 7A is composed of divided inner cylindrical shafts 7A1 and 7A2 that are divided into multiple parts in the axial direction corresponding to the limited height of the work space. The inner cylindrical shaft 7A has at least a first divided inner cylindrical shaft 7A1 provided with a locking mechanism 4 and a sealing mechanism 5, and a second divided inner cylindrical shaft 7A2 connected to the upper end of the first divided inner cylindrical shaft 7A1 by a connecting portion 11 formed of a male-female screw connection. In addition, a divided operating shaft can be further connected to the upper end of the second divided inner cylindrical shaft 7A2.

[0043] The outer cylindrical shaft 7B is composed of a hollow rod-shaped member that penetrates the center of a holding member 15 fixed to a top plate portion 30b of a work case 30 described later in a watertight manner and slides freely in the axial direction. The inner cylindrical shaft 7A is inserted into the outer cylindrical shaft 7B coaxially with the inner cylindrical shaft 7A, and a fluid flow path F that communicates with a fluid inlet portion 51 is formed in the gap between the inner cylindrical shaft 7A and the outer cylindrical shaft 7B.

[0044] The outer cylinder shaft 7B, like the inner cylinder shaft 7A, is composed of outer cylinder shafts 7B1 and 7B2 divided in the axial direction in accordance with the limited height of the working space. The outer cylinder shaft 7B is connected to the seal mechanism 5 by screwing the female thread portion 7Ba formed on the inner peripheral surface of the upstream end (lower end) into the male thread portion 56b1 of the first disk-shaped member 5Aa. The outer cylinder shaft 7B has at least a first split outer cylinder shaft 7B1 provided with the locking mechanism 4, the seal mechanism 5, and the holding member 15, and a second split outer cylinder shaft 7B2 connected to the upper end of the first split outer cylinder shaft 7B1 by a connecting portion 12 formed by male-female thread connection. A coupler 13a for supplying air from a fluid supply mechanism 13 such as an air pressure pump is connected to the upper end of the second split outer cylinder shaft 7B2. It is possible to further connect a split operating shaft to the upper end of the second split outer cylinder shaft 7B2.

[0045] A release prevention mechanism 10 is provided between the inner cylinder shaft 7A and the outer cylinder shaft 7B to prevent the release of the locking state of the locking mechanism 4. The release prevention mechanism 10 is composed of a male threaded portion 7Aa formed on the downstream end (upper end) of the inner cylinder shaft 7A, an operation nut 10A (one example of a nut) screwed onto the male threaded portion 7Aa, and a bearing 7Bb arranged on the downstream end face (upper face) of the outer cylinder shaft 7B and supporting the rotation of the operation nut 10A. The locking mechanism 4 is configured such that a pair of locking links 44 can be expanded in diameter by rotating the operation nut 10A. By rotating the operation nut 10A while sliding it against the bearing 7Bb, the inner cylinder shaft 7A rises and the pair of locking links 44 are expanded in diameter, and these locking links 44 engage with the branch flow passage opening periphery on the inner peripheral surface of the branch pipe section 2 (see also FIG. 9). Then, with the operating nut 10A being unable to rotate, the locking of the locking mechanism 4 is completed, and the operating nut 10A and the male thread portion 7Aa prevent the release of the locked state of the locking mechanism 4. 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 has been completed due to the operating nut 10A being unable to rotate. Note that 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 face) of the outer cylindrical shaft 7B.

[0046] The holding member 15 is a disk-shaped member that holds the outer cylindrical shaft 7B and is fixed to the top plate portion 30b of the work case 30 described later with a bolt B. The holding member 15 has a through hole 15a for the outer cylindrical shaft, into which the outer cylindrical shaft 7B is inserted, formed in the center. A pair of inner peripheral seal members sa are attached to the inner peripheral surface of the through hole 15a for the outer cylindrical shaft, and the outer cylindrical shaft 7B is held in a watertight state relative to the holding member 15 by the inner peripheral seal members sa. In addition, an outer peripheral seal member se is provided on the outer peripheral surface of the holding member 15 (annular groove in the top plate portion 30b), which prevents water leakage from a gap between the top plate portion 30b of the work case 30 and the holding member 15.

[0047] The branch flow path blocking device X described above is used by being attached to a work case 30. The work case 30 is a housing having a connecting flange portion 30a whose end portion protrudes radially outward, and has a top plate portion 30b whose central portion is open on the opposite side of 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 bumps and the like scraped off by a scraping cleaning tool (not shown) to the outside.

[0048] The top plate portion 30b is integrally formed with an outer peripheral wall portion 30ba having a circular cylindrical shape and an annular protruding portion 30bb, which is an upper end of the outer peripheral wall portion 30ba protruding radially inward. An annular groove is formed on the inner peripheral surface of the outer peripheral wall portion 30ba, into which the outer peripheral seal member se described above is attached, and the annular protruding portion 30bb is formed with a plurality of through holes into which the bolts B for fixing the holding member 15 are inserted. In addition, the annular protruding portion 30bb is formed with a notch portion 30bc for passing the coupler 13a when the work case 30 is removed.

[0049] A descent restriction device 24 is provided on the top plate 30b of the work case 30 to prevent the shaft member 7, to which the locking mechanism 4, the sealing mechanism 5, and the holding member 15 are attached, from descending under its own weight. The descent restriction device 24 is composed of a pair of clamping plates 24A capable of clamping and fixing the inner and outer cylindrical shafts 7A and 7B, a hexagon socket head bolt 24B that tightens and fixes both clamping plates 24A in a clamped state, and a gap adjustment bolt 24C that adjusts the gap between the clamping plates 24A and the top plate 30b.

[0050] Next, a branch passage blocking method and a fluid device updating method will be described with reference to FIGS.

[0051] The branch flow path blocking method includes a temporary blocking process of blocking the flow path of the branch pipe section 2 with an existing gate valve 3 (an example of a working valve, an example of an existing fluid equipment) as shown in Figure 7, a removal process of removing an existing air valve 6 (an example of an existing fluid equipment) connected to the branch pipe section 2 after the temporary blocking process, a mounting process of mounting a work case 30 in which an axial member 7 to which a locking mechanism 4 and a sealing mechanism 5 are connected is inserted in a sealed state to the branch pipe section 2 from which the air valve 6 has been removed, as shown in Figure 8, a locking process of opening the gate valve 3 and then operating the axial member 7 to lock the locking mechanism 4 to the branch flow path opening periphery (connection portion 2a) of the branch pipe section 2 as shown in Figure 9, and a blocking process of supplying air into the inside of the elastic member 5C to block the flow path of the branch pipe section 2.

[0052] Furthermore, the fluid equipment renewal method includes a first removal process of removing the work case 30 while leaving the branch flow path closing device X in place after the blocking process, as shown in Figure 10, a first installation process of installing a repair valve 8 (newly installed fluid equipment) and the work case 30 in the branch pipe section 2 after the first removal process, as shown in Figure 11, a second removal process of blocking the flow path of the branch pipe section 2 with the repair valve 8 and removing the branch flow path closing device X after the first installation process, as shown in Figure 12, and a second installation process of installing an air valve 9 (newly installed fluid equipment) in the repair valve 8 as shown in Figure 13.

[0053] As shown in Fig. 7, in the temporary blocking step, the valve body 3c of the existing gate valve 3 is moved to block the flow path of the branch pipe section 2. If the valve body 3c of the existing gate valve 3 is stuck and cannot be moved due to deterioration or the like, a clamping ring 16 is attached to the outer circumferential surfaces of both connecting flange sections 2c, 3a as shown in Fig. 14. This clamping ring 16 has a pair of clamping split rings 16A having a substantially semicircular arc shape and a gate valve 16C fixed to one of the clamping split rings 16A. After loosening the bolts and nuts of both connecting flange sections 2c, 3a, the connecting pieces 16B fixed to both circumferential ends of each clamping split ring 16A are pulled together and fixed by bolts and nuts. Then, the valve plate 16Ca of the gate valve 16C is inserted between both connecting flange sections 2c, 3a to block the flow path of the branch pipe section 2. After blocking the flow path of the branch pipe section 2, the existing air valve 6 is removed in a removal process. Although not shown, 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.

[0054] Next, as shown in Fig. 8, 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) supporting the locking mechanism 4 and the sealing mechanism 5 is held by the holding member 15 and clamped and fixed by the descent restrictor 24. At this time, as shown in the left diagram of Fig. 6, the first water stop fitting 5Ab abuts against the first disc-shaped member 5Aa and the second water stop fitting 5Bb abuts against the second disc-shaped member 5Ba, and the expansion portion 63 of the sealing mechanism 5 is housed in the work case 30 in an upright shape.

[0055] 9, the gate valve 3 is opened and the hexagon socket bolt 24B of the descent restrictor 24 is loosened, and then the shaft member 7 is operated manually or with a lowering tool such as a lever block (registered trademark) (not shown) to lower the locking mechanism 4 and the sealing mechanism 5. Then, when the locking mechanism 4 and the sealing mechanism 5 have been lowered until the upper ends of the second split inner cylinder shaft 7A2 and the second split outer cylinder shaft 7B2 are positioned on the top plate portion 30b of the work case 30, the third split inner cylinder shaft 7A3 and the third split outer cylinder shaft 7B3 are connected to the second split inner cylinder shaft 7A2 and the second split outer cylinder shaft 7B2. Next, the third split inner cylinder shaft 7A3 and the third split outer cylinder shaft 7B3 are operated manually or the like until the locking mechanism 4 is located at the branch flow passage opening periphery (connection portion 2a) of the branch pipe section 2, and then the fourth split inner cylinder shaft 7A4, in which the operation nut 10A is screwed onto the male threaded portion 7Aa at the downstream end (upper end) and the fourth split outer cylinder shaft 7B4, in which the coupler 13a and the bearing 7Bb are attached, are connected to the third split inner cylinder shaft 7A3 and the third split outer cylinder shaft 7B3. In this way, even if the height of the working space up to the ceiling wall R of the structure is limited, the working efficiency can be improved by using the shaft member 7 divided into multiple parts corresponding to the limited height of this working space.

[0056] Next, in the locking process, the inner cylindrical shaft 7A is pulled up by rotating the operation nut 10A while sliding against the bearing 7Bb arranged on the downstream end face (upper face) of the fourth split outer cylindrical shaft 7B4, and the locking mechanism 4 is locked to the branch flow passage opening periphery (connection part 2a) of the branch pipe section 2. More specifically, the inner cylindrical shaft 7A is moved downstream (upward) to bring the locking link 44 of the locking mechanism 4 into an expanded position and engages with the branch flow passage opening periphery on the inner peripheral surface of the branch pipe section 2. Since the operation nut 10A is no longer rotatable, the locking of the locking mechanism 4 is completed, and the operation nut 10A and the male threaded part 7Aa prevent the locking mechanism 4 from being released from the locked state. Next, the hexagon socket head bolt 24B of the descent restrictor 24 is tightened to clamp and fix the shaft member 7 (outer cylindrical shaft 7B). As a result, the descent restrictor 24 prevents the shaft member 7 (outer cylindrical shaft 7B) from falling due to its own weight.

[0057] Next, in the closing step, air is supplied to the inside of the elastic member 5C to close 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 inflow section 51 (see also the right diagram of FIG. 6). As a result, the expansion section 63 receives fluid pressure and expands radially outward, and comes into close contact with the inner surface of the branch pipe section 2 to close the flow path of the branch pipe section 2. In this way, the closing step of this embodiment does not require a large driving force such as a hydraulic jack, and only air needs to be supplied from the fluid inflow section 51, so that the work efficiency can be improved. Moreover, if the seal mechanism 5 is composed of the elastic member 5C that expands due to fluid pressure, it is possible to freely change the amount of expansion just by changing the fluid pressure, and it is possible to accommodate branch pipe sections 2 of any inner diameter without increasing the axial dimension of the device.

[0058] Next, as shown in FIG. 10, in the first removal step, the work case 30 and the gate valve 3 are removed while the branch flow path blocking device X is left behind. More specifically, the bolts B of the top plate portion 30b of the work case 30 are removed to release the fixation between the top plate portion 30b and the holding member 15, and the bolts and nuts fixing the connecting flange portion 30a of the work case 30 to the connecting flange portion 3b on the downstream side of the gate valve 3 are removed, and the work case 30 is removed. Then, the bolts and nuts fixing the connecting flange portion 2c of the branch pipe portion 2 to the connecting flange portion 3a on the upstream side of the gate valve 3 are removed, and the gate valve 3 is removed. At this time, the locking mechanism 4 is locked to the connection portion 2a between the branch pipe portion 2 and the water pipe 1, thereby preventing the shaft member 7 (inner cylinder shaft 7A) from moving upward due to the fluid pressure, and the downward movement of the shaft member 7 is prevented by supplying air to the seal mechanism 5 to block the flow path of the branch pipe portion 2. Furthermore, the operating nut 10A screwed into the male threaded portion 7Aa constituting the release prevention mechanism 10 abuts against the bearing 7Bb arranged on the downstream end face (upper face) of the outer cylindrical shaft 7B, thereby preventing the inner cylindrical shaft 7A from descending under its own weight and the locking link 44 from contracting in diameter, thereby preventing the release of the locked state of the locking mechanism 4. Also, since the radial dimension of the holding member 15 is smaller than the inner diameter of the gate valve 3, the work case 30 and the gate valve 3 can be removed reliably.

[0059] Next, as shown in FIG. 11, in the first installation step, after the first removal step, a new repair valve 8 is installed by fastening it to the branch pipe section 2 with a bolt and a nut, and the work case 30 is installed by fastening it to the new repair valve 8 with a bolt and a nut. Then, the top plate section 30b of the work case 30 and the holding member 15 are fixed with a bolt B, and the inside of the work case 30 is kept sealed. Next, the operation nut 10A screwed to 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 section 51 is stopped, and the fluid pressure acting on the elastic member 5C is reduced to reduce the diameter of the elastic member 5C (see also FIG. 12). Next, the shaft member 7 is operated manually or the like to raise the locking mechanism 4 and the seal mechanism 5. At this time, the shaft member 7 is raised while sequentially releasing the connection of the divided shaft members 7 until the locking mechanism 4 and the seal mechanism 5 are accommodated in the work case 30.

[0060] 12, in a second removal step, with the locking mechanism 4 and the sealing mechanism 5 housed in the work case 30, the flow path of the branch pipe section 2 is blocked by the repair valve 8, and the branch flow path blocking device X is removed. Finally, in a second installation step, as shown in FIG 13, an air valve 9 (newly installed fluid equipment) is installed in the repair valve 8, and the renewal of the fluid equipment is completed.

[0061] [Other embodiments] (1) The shaft member 7 may have a two-shaft structure in which the inner cylindrical shaft 7A that operates the locking mechanism 4 and the outer cylindrical shaft 7B that supplies air to the fluid inlet portion 51 are separate. (2) The locking mechanism 4 is not limited to the above-described embodiment as long as it can be changed to the diameter-expanded posture by operating the inner cylindrical shaft 7A. (3) In the above-described embodiment, the pair of upper annular members 5A is composed of the first disk-shaped member 5Aa and the first water-stopping fitting 5Ab, and the pair of lower annular members 5B is composed of the second disk-shaped member 5Ba and the 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 parts 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 formed to be movable. Even in this case, the first water-stopping fitting 5Ab and the second water-stopping fitting 5Bb have a separated structure that is relatively movable by screwing the clamping bolt 52 or the clamping bolt 53, 55a.

[0062] (4) The above-mentioned first clamped portion 61 and second clamped portion 62 do not have to be constructed of an elastic member 5C integrated with the expansion portion 63, but the first clamped portion 61 and second clamped portion 62, which are made of a metal or the like, may be connected to the expansion portion 63 as the elastic member 5C. (5) In the above embodiment, air is introduced into the sealing mechanism 5. However, liquid such as water may be introduced instead. (6) Instead of the holding member 15 described above, the sealing mechanism 5 may be provided with a mechanism for holding the inner cylindrical shaft 7A and the outer cylindrical shaft 7B. (7) Instead of the release prevention mechanism 10 described above, a mechanism for gripping the inner cylindrical shaft 7A may be provided separately. (8) In the above embodiment, the water pipe 1 through which clean water flows has been described. However, the water pipe 1 may be a fluid pipe through which a liquid other than clean water or a gas such as gas flows. [Industrial Applicability]

[0063] INDUSTRIAL APPLICABILITY The present invention can be used for a branch flow passage closing device that closes a flow passage of a branch pipe portion branched off from a fluid pipe, and for a branch flow passage closing method that uses the branch flow passage closing device. [Explanation of symbols]

[0064] 1: Water pipe (fluid pipe) 2: Branch pipe section 2a: Connection part 3: Gate valve (working valve) 4: Locking mechanism 5: Sealing mechanism 5Aa: First disk-shaped member (first annular member) 5Ab: First watertight fitting (first support part) 5Ba: Second disk-shaped member (second annular member) 5Bb: Second watertight fitting (second support part) 5C: Elastic material 6: Air valve (existing fluid equipment) 7: Shaft member 7A: Inner cylinder shaft 7B: Outer barrel shaft 10A: Operating nut (nut) 30: Working case 51:Fluid inlet 61:First clamped part 62:Second clamped part 63: Expansion section F: Fluid flow path X: Branch flow path blocking device

Claims

1. A branch flow path closing device that closes a flow path of a branch pipe portion branched from a fluid pipe, a locking mechanism that is locked to a connection portion between the branch pipe portion and the fluid pipe; a sealing mechanism having an elastic member capable of closing a flow path of the branch pipe portion; a shaft member supporting the locking mechanism and the sealing mechanism, the sealing mechanism includes a fluid inlet portion that allows a fluid to flow into the elastic member, a first support portion that supports one end of the elastic member, and a second support portion that supports the other end of the elastic member, The first support portion and the second support portion have a separate structure that is movable relative to each other, A branch flow path closing device in which, when the first support portion and the second support portion are separated from each other, a tensile force acts on the elastic member along the axial direction of the shaft member.

2. the sealing mechanism further includes a first annular member connected to the shaft member and a second annular member located closer to the fluid pipe than the first annular member, 2. The branch flow path blocking device as described in claim 1, wherein the elastic member has a first clamped portion clamped between the first annular member and the first support portion, a second clamped portion clamped between the second annular member and the second support portion, and an expansion portion connecting the first clamped portion and the second clamped portion and expanding when fluid flows in from the fluid inlet portion.

3. the shaft member has a single shaft structure including an inner cylinder shaft that operates the locking mechanism and an outer cylinder shaft into which the inner cylinder shaft is inserted coaxially with the inner cylinder shaft, 3. The branch flow path closing device according to claim 1, wherein a fluid flow path communicating with the fluid inlet portion is formed in a gap between the inner cylindrical shaft and the outer cylindrical shaft.

4. The branch flow path blocking device according to claim 1 , wherein the locking mechanism is configured to be expandable in diameter by rotating a nut.

5. A method for closing a branch flow path using the branch flow path closing device according to any one of claims 1 to 4, a temporary closing step of closing a flow path of the branch pipe section by an operating valve; a removal process of removing an existing fluid device connected to the branch pipe portion after the temporary closing process; an installation process of installing a work case in which the shaft member having the locking mechanism and the sealing mechanism is inserted in a sealed state to the branch pipe section from which the existing fluid equipment has been removed; a locking step of operating the shaft member to lock the locking mechanism to the connection portion after the operation valve is opened; a closing step of supplying a fluid into the inside of the elastic member to close the flow path of the branch pipe section.

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