Manifold forming device

Abstract

To provide a branch pipe forming device to which a drill machine can be attached, and which can further improve work efficiency.SOLUTION: A branch pipe forming device 100 attached to an existing pipe W in order to form a branch pipe 21 communicating with a drill port Wa formed by drilling the existing pipe W with a drill machine 1 in an uninterrupted state, comprises a split T-shaped pipe 3 covering the existing pipe W, and a branch pipe part 2 having the branch pipe 21. The split T-shaped pipe 3 is formed with swollen parts 31c, 32c that protrude outwards so as to face the drill port Wa when the split T-shaped pipe 3 is rotated while maintaining communication with the drill port Wa. The swollen parts 31c, 32c face an area of the outer periphery of the existing pipe W that is smaller than a semicircular area divided by a line segment including the center of the existing pipe W.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a branch pipe forming device attached to an existing pipe for forming a branch pipe that communicates with a perforation formed by perforating the existing pipe with a perforator in a non-stop flow state.

Background Art

[0002] Conventionally, there is known a branch pipe forming device attached to an existing pipe for forming a branch pipe that branches in a direction different from a predetermined direction through a perforation formed by perforating the existing pipe with a perforator from a predetermined direction in a non-stop flow state (see, for example, Patent Document 1).

[0003] The branch pipe forming device described in Patent Document 1 is composed of a first case body and a second case body, and includes a split T-shaped pipe that covers the existing pipe. The first case body is formed with a working pipe portion having a working valve. Further, a substantially 180-degree space is formed along the circumferential direction in this first case body. After forming the perforation, the split T-shaped pipe is rotated 90 degrees clockwise, and the perforation and the working pipe portion are communicated with each other through this space. After perforating from the vertical direction, by rotating the split T-shaped pipe 90 degrees clockwise, the operation portion of the working valve is configured to be operable from above.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the branch pipe forming device described in Patent Document 1 forms a working pipe portion having a working valve in the first case body and forms a space of approximately 180 degrees, when the split T-shaped pipe is rotated 90 degrees clockwise, the cut surface of the split T-shaped pipe must be formed in an oblique direction so that the perforation port and the working pipe portion communicate with each other. For this reason, it is difficult to position the split T-shaped pipe when installing it in an existing pipe, and there is room for improvement in terms of work efficiency.

[0006] Therefore, in a branch pipe forming device to which a drilling machine can be attached, a branch pipe forming device that can further improve work efficiency is desired.

Means for Solving the Problems

[0007] A characteristic configuration of the branch pipe forming device according to the present invention is a branch pipe forming device that is attached to an existing pipe in order to form a branch pipe that communicates with a perforation formed by perforating the existing pipe with a drilling machine in a non-stop flow state, and is connected Two It is formed of a divided housing, and includes a split T-shaped pipe that covers the existing pipe, and a branch pipe portion having the branch pipe connected to the split T-shaped pipe. The two divided casings are divided along the axis of the branch pipe portion, In the split T-shaped pipe, when the split T-shaped pipe is rotated while maintaining communication with the perforation port, a bulging portion that faces the perforation port protrudes outward, and the bulging portion is located at a point facing a region smaller than a semi-circular region divided by a line segment including the center of the existing pipe on the outer circumference of the existing pipe. Moreover, a characteristic configuration of the branch pipe forming device according to the present invention is a branch pipe forming device attached to an existing pipe in order to form a branch pipe communicating with a perforation formed by perforating the existing pipe with a perforator in a non-stop flow state, which is formed by two connected divided casings, and includes a split T-shaped pipe covering the existing pipe and a branch pipe portion having the branch pipe connected to the split T-shaped pipe. The two divided casings are divided in a direction perpendicular to the axis of the branch pipe portion. In the split T-shaped pipe, when the split T-shaped pipe is rotated while maintaining communication with the perforation, a bulging portion facing the perforation is formed to protrude outward. The bulging portion faces a region smaller than a semi-circular region divided by a line segment including the center of the existing pipe among the outer periphery of the existing pipe, and the bulging portion is formed across the two divided casings.

[0008] The branch pipe forming device having this configuration includes a split T-shaped pipe that covers an existing pipe and a branch pipe portion having a branch pipe connected to this split T-shaped pipe. For example, when a partition valve capable of closing the flow path of the branch pipe is provided in the branch pipe portion, since the split T-shaped pipe and the branch pipe portion are formed separately, the shape of the split T-shaped pipe is not restricted by the partition valve.

[0009] The bulging portion in this configuration faces a region smaller than the semi-circular region divided by a line segment including the center of the existing pipe on the outer periphery of the existing pipe. For this reason, the branch pipe forming device can be made more compact. Further, since the bulging portion faces a region smaller than the semi-circular region of the existing pipe, when the split T-shaped pipe is rotated, the risk of the bulging portion interfering with other structures is also reduced, and the excavation range can be minimized, thereby enhancing the working efficiency. Furthermore, by minimizing the bulging portion, it becomes possible to smoothly guide the fluid flowing out from the perforation opening to the branch pipe, and the pressure loss can be reduced.

[0010] Other characteristic configurations are On the existing pipe side of the branch pipe portion in the direction along the axis of the branch pipe portion, the split T-shaped pipe is connected. In the direction along the axis of the branch pipe portion, In the bottom wall located on the opposite side of the branch pipe portion of the bulging portion as opposed to a through hole capable of discharging fluid is formed, and a plug is attached to the through hole.

[0011] According to this configuration, a through hole is formed in the bottom wall of the bulging portion, and a plug is attached to this through hole. For this reason, when performing a perforation operation from above through the branch pipe portion, it becomes possible to direct the through hole downward, and the operations of discharging the fluid used in the sealing test before perforation and discharging the chips generated during the perforation operation together with the fluid can be executed extremely efficiently.

[0012] Another characteristic configuration is that a push bolt capable of abutting against the outer peripheral surface of the existing pipe is screwed into the split T-shaped pipe.

[0013] If a push bolt capable of abutting against the outer peripheral surface of the existing pipe is screwed into the split T-shaped pipe as in this configuration, the rotation of the split T-shaped pipe can be stopped simply by screwing in this push bolt and abutting it against the outer peripheral surface of the existing pipe.

[0014] Another characteristic configuration is that the split T-shaped pipe , before has a connecting opening for clamping the end portion of the branch pipe portion in a sealed state.

[0015] If the split T-shaped pipe is divided along the axial center of the branch pipe section and the end of the branch pipe is clamped in a sealed state at the connecting opening as in this configuration, even when a bending force or a tensile force acts on the branch pipe due to an earthquake or the like, it becomes possible to receive the load with the split T-shaped pipe, and the load applied to the connecting portion of the split T-shaped pipe can be reduced. Further, even when a bending force or a tensile force acts on the branch pipe due to an earthquake or the like, the branch pipe can move slightly flexibly, and the load applied to the connecting opening can be reduced.

[0016] Another characteristic configuration is that the split T-shaped pipe , before has a connecting flange portion connected to the end flange of the branch pipe section described above.

[0017] If the split T-shaped pipe is divided in a direction perpendicular to the axial center of the branch pipe section and the end flange of the branch pipe section is connected to the connecting flange portion of the split T-shaped pipe as in this configuration, even when a bending force or a tensile force acts on the branch pipe due to an earthquake or the like, it becomes a branch pipe forming device with high strength. Further, since the branch pipe section with a partition valve having an end flange can be configured with standard parts, it has become a highly versatile branch pipe forming device.

Brief Description of the Drawings

[0018]

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Embodiments for Carrying Out the Invention

[0019] Hereinafter, an embodiment of the branch pipe forming device according to the present invention will be described with reference to the drawings. In the present embodiment, as an example of the branch pipe forming device, the renewal of the water pipe W (an example of an existing pipe) constituting the fluid piping system, the branch pipe forming device 100 attached to the water pipe W during earthquake-proof reinforcement work, and the branch pipe forming method using the branch pipe forming device 100 will be described. However, the present invention is not limited to the following embodiments, and various modifications are possible without departing from the gist of the invention.

[0020] [First Embodiment] As shown in FIGS. 1 to 3, the branch pipe forming device 100 is attached to the water pipe W to form a branch pipe 21 that communicates with a perforation opening Wa formed by perforating a part of the outer peripheral surface of the water pipe W (an example of an existing pipe) in a non-stop flow state by a perforator 1. This branch pipe forming device 100 includes a split T-shaped pipe 3 having a split structure and a branch pipe portion 2 connected to the split T-shaped pipe 3.

[0021] The split T-shaped pipe 3 is formed of a plurality (two in the present embodiment) of connected split housings and covers the water pipe W in a sealed state. The split T-shaped pipe 3 has a pair of split surfaces 31a and 32a perpendicular to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21, and is composed of a first split member 31 and a second split member 32 that are connected to each other in a sealed state by an annular seal member 35 disposed between these split surfaces 31a and 32a. Here, the "split surfaces 31a and 32a perpendicular to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21" means that the split surfaces 31a and 32a are on a plane perpendicular to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21 or a plane substantially parallel to the plane. In other words, the split T-shaped pipe 3 in the present embodiment is split in a direction perpendicular to the axis Y of the branch pipe 21. The water pipe W, the branch pipe portion 2, and the split T-shaped pipe 3 in the present embodiment are formed using the same kind of material such as a cast iron pipe or a steel pipe. Note that the water pipe W and the branch pipe portion 2 or the split T-shaped pipe 3 may be formed using different materials.

[0022] When the drilling machine 1 is attached to the branch pipe forming device 100, it is attached along the outer peripheral surface of the water pipe W such that the first dividing member 31 is disposed on the lower side in the vertical direction and the second dividing member 32 is disposed on the upper side in the vertical direction. The first dividing surface 31a of the first dividing member 31 and the second dividing surface 32a of the second dividing member 32 are along a horizontal plane parallel to the ground (see FIG. 1). Hereinafter, the description may be made with the gravity direction being downward and the opposite direction being upward.

[0023] The first dividing member 31 is composed of a half-dividing member, and has a semi-cylindrical first main body portion 31b along the outer peripheral surface of the water pipe W, a first bulging portion 31c protruding outward from the first main body portion 31b, and a first flange portion 31d extending outward across the first main body portion 31b and the first bulging portion 31c.

[0024] The first main body portion 31b is curved along the outer peripheral surface of the water pipe W, and a plurality of through holes (not shown) into which a push bolt 33 whose tip contacts the outer peripheral surface of the water pipe W is inserted are formed at both ends in the axial core X direction of the water pipe W (see FIG. 2). By the push bolt 33 contacting the outer peripheral surface of the water pipe W, the first dividing member 31 is fixed in position on the water pipe W so as not to rotate.

[0025] The first bulging portion 31c is located on one side with respect to the axial core Y of the branch pipe 21. At the time of drilling, it is on the left side with respect to the axial core Y of the branch pipe 21 in the vertical direction (in the state of FIG. 1), and when the branch pipe forming device 100 is rotated 90 degrees clockwise, it is on the upper side with respect to the axial core Y of the branch pipe 21 in the horizontal direction (in the state of FIG. 3). Further, when the branch pipe forming device 100 is rotated 90 degrees clockwise, the first bulging portion 31c faces the drilling hole Wa, and a flow space S through which water (an example of a fluid) can flow is formed inside the first bulging portion 31c. The first bulging portion 31c has a bottom wall 31c1 located on the opposite side of the branch pipe portion 2 and a first side wall 31c2 standing vertically from the bottom wall 31c1. A through hole (not shown) through which water can be discharged is formed in this bottom wall 31c1, and a plug P is attached to this through hole (not shown).

[0026] The first flange portion 31d stands upright outward from the end portion on the side opposite to the bottom wall 31c1 of the first side wall 31c2 and both end portions of the first main body portion 31b (see FIGS. 1 and 2). A plurality of first through-hole portions (not shown) into which bolts Ba constituting the fastening member B are inserted are formed along the axis Y in the first flange portion 31d.

[0027] The second split member 32 is composed of split members, and includes a semi-cylindrical second main body portion 32b along the outer peripheral surface of the water pipe W, a second bulging portion 32c protruding outward from the second main body portion 32b, a second flange portion 32d extending outward across both end portions of the second main body portion 32b and one end portion of the second bulging portion 32c, a connecting opening portion 32e protruding toward the branch pipe portion 2 across the central portion of the second main body portion 32b and the other end portion of the second bulging portion 32c, and a connecting flange portion 32f that is externally fitted or integrally protrudes annularly outward from the connecting opening portion 32e. In the present embodiment, the connecting flange portion 32f is externally fitted to the connecting opening portion 32e using a detachment prevention fitting 34 described later. When the connecting flange portion 32f is integrally formed with the connecting opening portion 32e, the detachment prevention fitting 34 can be omitted.

[0028] The second main body portion 32b is curved along the outer peripheral surface of the water pipe W, and a plurality of through-holes (not shown) into which push bolts 33 whose tips abut against the outer peripheral surface of the water pipe W are inserted are formed at both end portions in the axial direction X of the water pipe W (see FIG. 2). By the push bolts 33 abutting against the outer peripheral surface of the water pipe W, the second split member 32 is fixedly positioned on the water pipe W so as not to rotate.

[0029] The second bulging portion 32c is located on one side with respect to the axis Y of the branch pipe 21. During punching, it is on the left side with respect to the axis Y of the branch pipe 21 in the vertical direction (the state of FIG. 1), and when the branch pipe forming device 100 is rotated 90 degrees clockwise, it is located on the upper side with respect to the axis Y of the branch pipe 21 in the horizontal direction (the state of FIG. 3). Further, when the branch pipe forming device 100 is rotated 90 degrees clockwise, the second bulging portion 32c faces the punching opening Wa, and a flow space S through which water can flow is formed inside the second bulging portion 32c. The second bulging portion 32c has a second side wall 32c1 located on the opposite side of the branch pipe portion 2, and this second side wall 32c1 is continuous with the first side wall 31c2 of the first bulging portion 31c and is curved along the curved surface shape of the outer peripheral surface of the water pipe W. The first bulging portion 31c and the second bulging portion 32c face a region smaller than the semi-circular region divided by the line segment (diameter) including the center of the water pipe W among the outer periphery of the water pipe W. As the formation range of the bulging portions 31c and 32c, the central angle θ of the water pipe W is 90 degrees or more and less than 180 degrees with respect to the outer periphery of the water pipe W, preferably 100 degrees or more and 150 degrees or less, and more preferably 110 degrees or more and 130 degrees or less. This central angle θ is set so that the flow space S faces across the punching opening Wa when the branch pipe forming device 100 is rotated 90 degrees clockwise according to the size of the punching opening Wa.

[0030] The second flange portion 32d stands upright outward from both end portions of the second main body portion 32b and the end portion on the opposite side of the connection opening 32e of the second side wall 32c1. A plurality of second through-hole portions (not shown) into which the bolt Ba is inserted are formed along the axis Y in a state where the second flange portion 32d faces the first flange portion 31d, and a nut Bb screwed onto the bolt Ba is arranged on the outer surface.

[0031] A detachment prevention fitting 34 is attached to the connection opening 32e. The claw member 34a of the detachment prevention fitting 34 bites into the outer surface of the connection opening 32e as the split T-shaped pipe 3 and the branch pipe 21 move relatively apart, preventing the split T-shaped pipe 3 and the branch pipe 21 from detaching (see also Fig. 4). In the present embodiment, the connection opening 32e serves as an insertion pipe that is inserted into the branch pipe 21 of the branch pipe section 2. Note that the detachment prevention fitting 34 may be omitted, and the connection flange section 32f may be formed integrally with the connection opening 32e.

[0032] The connection flange section 32f is formed integrally with the detachment prevention fitting 34 and is connected to the end flange 22 on one side of the branch pipe section 2 by bolts 23 and nuts 24.

[0033] The branch pipe section 2 includes a branch pipe 21 connected to the split T-shaped pipe 3 and a shut-off valve V capable of closing the flow path of the branch pipe 21. In the present embodiment, the branch pipe section 2 is a standard product (such as JWWA B 120, etc.) and has an end flange 22 on one side that is connected to the connection flange section 32f of the split T-shaped pipe 3 by bolts 23 and nuts 24.

[0034] As shown in Fig. 1, the drilling machine 1 includes a cylindrical hole saw 11 (cutter) having a cutting tip 11a, a center drill 12 that protrudes outward from the center position of the hole saw 11 beyond the cutting tip 11a, a rotary drive mechanism 13 including a motor that rotationally drives the hole saw 11 and the center drill 12, and a drilling case 14 that houses the hole saw 11 and the center drill 12.

[0035] The hole saw 11 in this embodiment is configured such that its outer diameter is smaller than the outer diameter (diameter) of the water pipe W, and it cuts a part of the outer peripheral surface of the water pipe W to form one perforation opening Wa. The hole saw 11 and the center drill 12 are connected to the rotating shaft 13a of the rotation drive mechanism 13 and move forward and backward along the axis Y of the branch pipe 21 (in the vertical direction) while rotating. When the rotation drive mechanism 13 rotates the hole saw 11 downward while rotating it toward the water pipe W, a part (upper surface) of the outer peripheral surface of the water pipe W is cut by the cutting tip 11a of the hole saw 11, and the perforation opening Wa is formed (see also FIG. 3). This perforation opening Wa has a shape that conforms to the outer shape of the hole saw 11 and is formed in a circular shape in a plan view along the axis Y of the branch pipe 21.

[0036] When the rotation drive mechanism 13 moves the hole saw 11 and the center drill 12 forward, a cutter accommodation space Sp capable of accommodating the hole saw 11 is formed in the connection opening 32e of the second split member 32 at a position facing the perforation opening Wa (see also FIG. 5). The center drill 12 in this embodiment has the corners of the entire circumferential direction of the tip surface of the tip portion 12a formed in a tapered shape, and an engaging member 12a1 capable of holding a cut portion (chip) is engaged with the side surface of the tip portion 12a.

[0037] Subsequently, with reference to FIGS. 4 to 7, a method for forming a branch pipe using the branch pipe forming device 100 will be described. In this embodiment, by attaching the branch pipe forming device 100 to a predetermined portion of the water pipe W, a branch pipe 21 intended to communicate with the water pipe W is formed and perforated, and then the branch pipe forming device 100 is rotated 90 degrees clockwise to communicate the perforation opening Wa and the branch pipe 21 via the flow space S.

[0038] The method for forming a branch pipe in this embodiment includes (1) a step of attaching the branch pipe forming device, (2) a perforation step, (3) a device rotation step, and (4) a step of passing water through the branch pipe.

[0039] (1) Step of attaching the branch pipe forming device As shown in FIG. 4, after excavating around the water pipe W, the first split member 31 and the second split member 32 are arranged on the water pipe W such that the cut surfaces 31a of the first split member 31 and the cut surfaces 32a of the second split member 32 are along a direction (left - right direction) perpendicular to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21.

[0040] Specifically, first, the first split member 31 fitted with the annular seal member 35 is arranged below the water pipe W. If there is a pedestal that can maintain the first split member 31 in a horizontal state, the first split member 31 may be arranged on this pedestal.

[0041] The second split member 32 fitted with the annular seal member 35 is brought close to the upper side of the first split member 31, and the cut surface 31a of the first split member 31 and the cut surface 32a of the second split member 32 are opposed to each other. In this way, since the first split member 31 and the second split member 32 constituting the branch pipe forming device 100 are composed of cut surfaces 31a and 32a perpendicular to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21, it is easy to mount the second split member 32 on the first split member 31 with the first split member 31 arranged in the vertically downward direction.

[0042] Then, the first split member 31 and the second split member 32 are connected in a sealed state by the fastening member B. This fastening member B will be arranged at eight positions on the first flange portion 31d of the first split member 31 and the second flange portion 32d of the second split member 32. By the fastening operation using this fastening member B, the annular seal member 35 fitted to the first cut surface 31a and the annular seal member 35 fitted to the second cut surface 32a are pressed against each other, thereby sealing the gap between the first split member 31 and the second split member 32. Next, by screwing the push bolt 33 into the first split member 31 and the second split member 32, the tip of the push bolt 33 is brought into contact with the outer surface of the water pipe W so that the first split member 31 and the second split member 32 do not rotate, and they are fixed in position (see also FIG. 1).

[0043] Next, insert the connection opening 32e of the second split member 32 into the branch pipe 21 of the branch pipe section 2 so that the connection flange section 32f of the second split member 32 faces the end flange 22 on one side of the branch pipe section 2, and connect them with bolts 23 and nuts 24. At this time, since it is composed of cross-sectional planes 31a and 32a perpendicular to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21, the operation of inserting the connection opening 32e of the second split member 32 into the branch pipe 21 of the branch pipe section 2 and the fastening operation of the bolts 23 and nuts 24 are easy.

[0044] This branch pipe forming device mounting process includes a hydrostatic test process in which water is supplied into the first split member 31 and the second split member 32 to perform a sealing test. In this hydrostatic test process, through holes (not shown) formed in the bottom walls 31c1 of the bulging portions 31c and 32c are utilized for water discharge, and plugs P are mounted in the through holes (not shown) during normal times and sealing tests. In the hydrostatic test process, a lid member 26 for water introduction is mounted on the end flange 25 on the other side of the branch pipe section 2, water is allowed to flow in from the connection opening 32e through the branch pipe section 2 with the partition valve V opened, and the sealing states of the first split member 31 and the second split member 32 are confirmed. Thereby, it becomes possible to perform a sealing test before mounting the drilling machine 1 or the like.

[0045] (2) Drilling process As shown in FIG. 5, the drilling process includes a drilling machine mounting process of mounting the drilling machine 1 on the branch pipe section 2, a drilling hole forming process of moving the hole saw 11 of the drilling machine 1 to the cutter accommodation space Sp formed in the second split member 32 to form a drilling hole Wa at a position adjacent to the cutter accommodation space Sp, and a branch flow path closing process of closing the partition valve V provided in the branch pipe section 2.

[0046] In the process of mounting the drilling machine, the drilling flange 14a of the drilling case 14 is fixed to the end flange 25 on the other side of the branch pipe portion 2 with bolts and nuts, and the drilling machine 1 is mounted on the branch pipe portion 2. In the process of forming the drilling hole, when the hole saw 11 and the center drill 12 are advanced to the vicinity of the water pipe W and then advanced downward while being rotated by the rotation drive mechanism 13, first the center drill 12 drills the water pipe W, and then a part (upper surface) of the outer peripheral surface of the water pipe W is cut by the cutting tip 11a of the hole saw 11, and the drilling hole Wa is formed. At this time, since the split surfaces 31a and 32a of the first split member 31 and the second split member 32 are in the horizontal direction, compared with the case where the split surfaces 31a and 32a are in the vertical direction, the vibration of the drilling machine 1 does not directly act on the split surfaces 31a and 32a, and the deviation of the cutter axis of the drilling operation is small. The cut portion (chip) generated by the formation of the drilling hole Wa is held by the engaging member 12a1 of the center drill 12 and recovered inside the drilling case 14 by retracting the hole saw 11 and the center drill 12 upward.

[0047] In the process of closing the branch flow path, by closing the shut-off valve V provided in the branch pipe portion 2, it is possible to prevent water from leaking from the water pipe W through the drilling hole Wa formed in the process of forming the drilling hole. The chips generated by the drilling operation can be discharged and removed to the outside together with water by removing the plug P of the through hole (not shown) formed in the bottom wall 31c1 of the bulging portions 31c and 32c. After the process of closing the branch flow path, the drilling machine 1 is removed. When discharging the chips in the process of closing the branch flow path, a ball valve is connected to the through hole in advance, and the ball valve is closed after draining, but detailed description is omitted.

[0048] (3) Device rotation process As shown in Fig. 6, in the device rotation step, the pressing bolt 33 is loosened to rotate the branch pipe forming device 100 by a predetermined angle (90 degrees clockwise in this embodiment), and after the bulging portions 31c and 32c are opposed to the perforation opening Wa, the pressing bolt 33 is tightened again to bring the tip of the pressing bolt 33 into contact with the outer surface of the water pipe W, thereby fixing the position of the branch pipe forming device 100. Thereby, the communication between the branch pipe portion 2 and the perforation opening Wa is maintained. After connecting a pipe to the end flange 25 on the other side of the branch pipe portion 2, by opening the shut-off valve V, the flow path of the water pipe W can be switched.

[0049] The branch pipe forming device 100 of the present embodiment includes a split T-shaped pipe 3 that covers the water pipe W and a branch pipe portion 2 having a branch pipe 21 connected to the split T-shaped pipe 3. Since a shut-off valve V capable of closing the flow path of the branch pipe 21 is provided in the branch pipe portion 2, the shape of the split T-shaped pipe 3 is not restricted by the shut-off valve V. In other words, when the split T-shaped pipe 3 and the branch pipe portion 2 are rotated while maintaining the communication between the branch pipe portion 2 and the perforation opening Wa, bulging portions 31c and 32c that face the perforation opening Wa are formed to protrude outward. However, the formation range of the bulging portions 31c and 32c is not restricted by the shut-off valve V.

[0050] Further, since the bulging portions 31c and 32c face a region smaller than the semi-circular region divided by a line segment including the center of the water pipe W on the outer periphery of the water pipe W, the branch pipe forming device 100 can be made more compact. Furthermore, since the bulging portions 31c and 32c face a region smaller than the semi-circular region of the water pipe W, when the split T-shaped pipe 3 is rotated, the possibility that the bulging portions 31c and 32c interfere with other structures is also reduced, and the excavation range can be minimized, thereby improving the working efficiency.

[0051] Further, since the split T-shaped pipe 3 is divided in a direction perpendicular to the axis Y of the branch pipe portion 2 and the end flange 22 of the branch pipe portion 2 is connected to the connecting flange portion 32f of the split T-shaped pipe 3, even when a bending force or a tensile force acts on the branch pipe 21 due to an earthquake or the like, the branch pipe forming device 100 has high strength. In particular, since the connecting opening 32e is an insertion pipe inserted into the branch pipe 21 of the branch pipe portion 2 and the anti-separation fitting 34 is provided at the connecting opening 32e, even when a bending force or a tensile force acts on the branch pipe 21 due to an earthquake or the like, the branch pipe 21 can move slightly and flexibly, and the load applied to the connecting opening 32e can be reduced. Further, since the branch pipe portion 2 with the partition valve V having a pair of end flanges 22 and 25 is a standard product, the branch pipe forming device 100 has high versatility.

[0052] (4) Branch pipe water passing process As shown in FIG. 7, in the branch pipe water passing process, after a new pipe 5 is connected to the end flange 25 on the other side of the branch pipe portion 2 to form a branch flow path, the partition valve V of the branch pipe forming device 100 is opened to pass water through the branch pipe 21. In the present embodiment, since the bulging portions 31c and 32c are located only on the upper side with respect to the axis Y of the branch pipe 21 in the left-right direction when the branch pipe forming device 100 is rotated 90 degrees clockwise, a flow path (flow space S) leading to the connecting opening 32e of the split T-shaped pipe 3 can be smoothly formed. That is, compared with the case where the bulging portions 31c and 32c are formed to extend below the connecting opening 32e, a water accumulation portion is not formed, and the pressure loss associated with the flow path switching can be reduced.

[0053] Hereinafter, for other embodiments, members having the same functions and structures as those in the first embodiment will be described using the same names and the same reference numerals. In addition, mainly the configurations different from those in the first embodiment will be described, and the description of the same configurations may be omitted.

[0054] [Second Embodiment] As shown in FIGS. 8 and 9, the branch pipe forming device 100A includes a split T-shaped pipe 3A having a split structure and a branch pipe portion 2A connected to the split T-shaped pipe 3A.

[0055] The split T-shaped pipe 3A is formed of a plurality (two in this embodiment) of connected split housings, and covers the water pipe W in a sealed state. This split T-shaped pipe 3A has split surfaces 31Aa and 32Aa parallel to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21A, and is composed of a first split member 31A and a second split member 32A that are connected to each other in a sealed state by an annular seal member 35 disposed between these split surfaces 31Aa and 32Aa. Here, the "split surfaces 31a and 32a parallel to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21A" means that the split surfaces 31Aa and 32Aa are on the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21A or on a plane substantially parallel to the plane. In other words, the split T-shaped pipe 3A in this embodiment is split along the axis Y of the branch pipe 21A.

[0056] When the drilling machine 1 is attached to the branch pipe forming device 100A, the first split member 31A is disposed on the left side and the second split member 32A is disposed on the right side with respect to the axis X of the water pipe W, and they are attached along the outer peripheral surface of the water pipe W. The first split surface 31Aa of the first split member 31A and the second split surface 32Aa of the second split member 32A are along a vertical plane perpendicular to the ground (see FIG. 9).

[0057] The first split member 31A is composed of a half split member, and has a semi-cylindrical first main body portion 31Ab along the outer peripheral surface of the water pipe W, a bulging portion 31Ac protruding outward from the first main body portion 31Ab, a first flange portion 31Ad extending outward from the first main body portion 31Ab, and a connecting opening portion 31Ae protruding from the first main body portion 31Ab and the bulging portion 31Ac toward the branch pipe portion 2A.

[0058] The first main body portion 31Ab is curved along the outer peripheral surface of the water pipe W, and a plurality of block portions 33A into which a push bolt 33 whose tip abuts against the outer peripheral surface of the water pipe W is inserted protrude outward (see FIG. 8). By the push bolt 33 abutting against the outer peripheral surface of the water pipe W, the first split member 31A is fixed in position on the water pipe W so as not to rotate.

[0059] The bulging portion 31Ac is located on one side with respect to the axis Y of the branch pipe 21A. During punching, it is on the left side with respect to the axis Y of the branch pipe 21A in the vertical direction (the state in FIG. 9), and when the branch pipe forming device 100A is rotated 90 degrees clockwise, it is located above with respect to the axis Y of the branch pipe 21A in the horizontal direction. Further, when the branch pipe forming device 100A is rotated 90 degrees clockwise, the bulging portion 31Ac faces the punching opening Wa, and a flow space SA through which water can flow is formed inside the bulging portion 31Ac. The bulging portion 31Ac has a bottom wall 31Ac1 located on the opposite side of the branch pipe portion 2A and a side wall 31Ac2 standing vertically from the bottom wall 31Ac1. A through hole (not shown) through which water can be discharged is formed in this bottom wall 31Ac1, and a plug P is attached to this through hole (not shown). This bulging portion 31Ac faces a region smaller than a semi-circular region divided by a line segment (diameter) including the center of the water pipe W among the outer circumference of the water pipe W. As the formation range of the bulging portion 31Ac, the central angle θ of the water pipe W is 80 degrees or more and less than 180 degrees with respect to the outer circumference of the water pipe W, preferably 90 degrees or more and 140 degrees or less, and more preferably 90 degrees or more and 110 degrees or less. This central angle θ is set so that the flow space SA faces across the punching opening Wa when the branch pipe forming device 100A is rotated 90 degrees clockwise according to the size of the punching opening Wa.

[0060] The first flange portion 31Ad stands upright outward from the end of the first main body portion 31Ab on the side opposite to the bulging portion 31Ac. A plurality of first through hole portions (not shown) into which bolts Ba are inserted are formed along a direction perpendicular to the axis Y in a state where the first flange portion 31Ad faces the second flange portion 32Ad, and nuts Bb screwed onto these bolts Ba are arranged on the outer surface.

[0061] The second divided member 32A is composed of a half member, and has a semi-cylindrical second main body portion 32Ab along the outer peripheral surface of the water pipe W, a second flange portion 32Ad extending outward from the second main body portion 32Ab, and a connection opening portion 32Ae protruding from the second main body portion 32Ab toward the branch pipe portion 2A.

[0062] The second main body portion 32Ab is curved along the outer peripheral surface of the water pipe W, and a plurality of block portions 33A into which a push bolt 33 whose tip abuts against the outer peripheral surface of the water pipe W is inserted are formed to protrude outward. By the push bolt 33 abutting against the outer peripheral surface of the water pipe W, the second split member 32A is fixed in position to the water pipe W so as not to rotate.

[0063] The second flange portion 32Ad has a plurality of second through-hole portions (not shown) into which the bolt Ba is inserted formed along a direction perpendicular to the axis Y in a state of facing the first flange portion 31Ad.

[0064] The connection openings 31Ae and 32Ae are formed across the first split member 31A and the second split member 32A, and when the connection openings 31Ae and 32Ae are fastened by the fastening member B, they form an integral opening (see FIG. 8). An annular convex portion 36a that abuts against the end flange 20A of the branch pipe 21A described later and prevents the branch pipe 21A from coming off protrudes inward from the inner peripheral surface in the connection openings 31Ae and 32Ae (see FIG. 9). Further, in the connection openings 31Ae and 32Ae other than the bulging portions 31Ac of the second split member 32A and the first split member 31A, a semi-circular convex portion 36b that abuts against the tip surface of the branch pipe 21A and prevents the branch pipe 21A from falling during drilling protrudes inward from the inner peripheral surface. In the connection openings 31Ae and 32Ae continuous with the bulging portions 31Ac of the second split member 32A and the first split member 31A, a semi-circular locking portion 36c that abuts against a C-ring 20Ab described later and prevents the branch pipe 21A from falling during drilling protrudes inward from the inner peripheral surface. Furthermore, an annular seal member 35 that is compressed is fitted to the opening sides of the connection openings 31Ae and 32A and the first flange portion 31Ad and the second flange portion 32Ad when the first split member 31A and the second split member 32A are fastened by the fastening member B. Thereby, the connection openings 31Ae and 32A sandwich the end portion of the branch pipe 21A in a sealed state.

[0065] The end flange 20A of the manifold 21A is clamped between the connecting openings 31Ae and 32Ae of the first split member 31A and the second split member 32A. The end flange 20A in the present embodiment is composed of an annular protrusion 20Aa formed at the end of the manifold 21A and a C-ring 20Ab fitted so as to abut against the annular protrusion 20Aa. By the C-ring 20Ab abutting against the above-described annular convex portion 36a or the semi-circular locking portion 36c and the front end surface of the manifold 21A abutting against the above-described semi-circular convex portion 36b, while allowing minute movement of the manifold 21A, disengagement prevention and dropping are prevented.

[0066] The manifold forming method in the present embodiment includes a manifold forming apparatus mounting step, a piercing step, an apparatus rotation step, and a manifold water passing step, which are the same as those in the first embodiment, and a detailed description thereof will be omitted. As in the present embodiment, if the split T-shaped pipe 3A is split along the axis Y of the manifold portion 2A and the end of the manifold 21A is clamped in a sealed state at the connecting openings 31Ae and 32Ae, even when a bending force or a tensile force acts on the manifold 21A due to an earthquake or the like, it becomes possible to receive the load by the split T-shaped pipe 3A, and the load applied to the connecting portion of the split T-shaped pipe 3A can be reduced. Further, even when a bending force or a tensile force acts on the manifold 21A due to an earthquake or the like, the manifold 21A can move minutely in a flexible manner, and the load applied to the connecting openings 31Ae and 32Ae can be reduced. Other operational effects are the same as those in the first embodiment.

[0067] [Third Embodiment] As shown in FIGS. 10 and 11, the manifold forming apparatus 100B includes a split T-shaped pipe 3B having a split structure and a manifold portion 2B connected to the split T-shaped pipe 3B.

[0068] The split T-shaped pipe 3B is formed of a plurality of (two in the present embodiment) connected split housings and covers the water pipe W in a sealed state. This split T-shaped pipe 3B has split surfaces 31Ba and 32Ba parallel to the plane including the axis X of the water pipe W and the axis Y of the manifold 21B, and is composed of a first split member 31B and a second split member 32B that are connected to each other in a sealed state by an annular seal member 35 disposed between these split surfaces 31Ba and 32Ba.

[0069] When the perforator 1 is attached to the branch pipe forming device 100B, it is attached along the outer peripheral surface of the water pipe W such that the first dividing member 31B is disposed on the left side and the second dividing member 32B is disposed on the right side, and the first cut surface 31Ba of the first dividing member 31B and the second cut surface 32Ba of the second dividing member 32B are along a vertical plane perpendicular to the ground.

[0070] The first dividing member 31B is composed of a half-dividing member, and has a semi-cylindrical first main body portion 31Bb that follows the outer peripheral surface of the water pipe W, a bulging portion 31Bc that protrudes outward from the first main body portion 31Bb, a first flange portion 31Bd that extends outward from the first main body portion 31Bb, and a connecting opening portion 31Be that protrudes from the first main body portion 31Bb and the bulging portion 31Bc toward the branch pipe portion 2B.

[0071] The first main body portion 31Bb is curved along the outer peripheral surface of the water pipe W, and a plurality of block portions (not shown, similar to the second embodiment) into which a push bolt (not shown, similar to the second embodiment) whose tip abuts against the outer peripheral surface of the water pipe W is inserted are formed to protrude outward.

[0072] The bulging portion 31Bc is located on one side with respect to the axis Y of the branch pipe 21B. During piercing, it is on the left side with respect to the axis Y of the vertically oriented branch pipe 21B (the state in FIG. 10), and when the branch pipe forming device 100B is rotated 90 degrees clockwise, it is located above the axis Y of the horizontally oriented branch pipe 21B (the state in FIG. 11). Further, when the branch pipe forming device 100B is rotated 90 degrees clockwise, the bulging portion 31Bc faces the piercing opening Wa, and a flow space SB through which water can flow is formed inside the bulging portion 31Bc. The bulging portion 31Bc has a bottom wall 31Bc1 located on the side opposite to the branch pipe portion 2B, and a side wall 31Bc2 standing vertically from the bottom wall 31Bc1. A through hole (not shown) through which water can be discharged is formed in this bottom wall 31Bc1, and a plug P is attached to this through hole (not shown). This bulging portion 31Bc faces a region smaller than a semi-circular region divided by a line segment (diameter) including the center of the water pipe W on the outer periphery of the water pipe W. As the formation range of the bulging portion 31Bc, the central angle θ of the water pipe W is 80 degrees or more and less than 180 degrees with respect to the outer periphery of the water pipe W, preferably 90 degrees or more and 140 degrees or less, and more preferably 90 degrees or more and 110 degrees or less. This central angle θ is set so that the flow space SB faces across the piercing opening Wa when the branch pipe forming device 100B is rotated 90 degrees clockwise according to the size of the piercing opening Wa.

[0073] The first flange portion 31Bd stands upright outward from the end of the first main body portion 31Bb on the side opposite to the bulging portion 31Bc. A plurality of first through hole portions (not shown) into which bolts Ba are inserted are formed along a direction perpendicular to the axis Y in a state where the first flange portion 31Bd faces the second flange portion 32Bd of the second dividing member 32B, and nuts Bb screwed onto these bolts Ba are arranged on the outer surface.

[0074] The second dividing member 32B is composed of a half-dividing member, and has a semi-cylindrical second main body portion 32Bb along the outer peripheral surface of the water pipe W, a second flange portion 32Bd extending outward from the second main body portion 32Bb, and a connecting opening portion 32Be protruding from the second main body portion 32Bb toward the branch pipe portion 2B.

[0075] The second main body portion 32Bb is curved along the outer peripheral surface of the water pipe W, and a plurality of block portions (not shown, similar to the second embodiment) into which a push bolt (not shown, similar to the second embodiment) whose tip contacts the outer peripheral surface of the water pipe W is inserted are formed to protrude outward.

[0076] The second flange portion 32Bd has a plurality of second through-hole portions (not shown) into which the bolt Ba is inserted in a state facing the first flange portion 31Bd formed along a direction perpendicular to the axis Y.

[0077] The connection openings 31Be and 32Be are formed across the first split member 31B and the second split member 32B, and when the connection openings 31Be and 32Be are fastened by the fastening member B, they become an integral opening. An annular convex portion 36a that contacts the end flange 20B of the branch pipe 21B described later and prevents the branch pipe 21B from coming off protrudes inward from the inner peripheral surface in the connection openings 31Be and 32Be. The front end surface of the branch pipe 21B includes a main pipe contact portion 21Ba that contacts the outer surface of the water pipe W and prevents the branch pipe 21B from falling during drilling. Further, an annular seal member 35 that is compressed is fitted to the opening sides of the connection openings 31Be and 32Be and the first flange portion 31Bd and the second flange portion 32Bd when the first split member 31B and the second split member 32B are fastened by the fastening member B. Thereby, the connection openings 31Be and 32Be sandwich the end portion of the branch pipe 21B in a sealed state.

[0078] The end flange 20B of the branch pipe 21B is sandwiched between the connection openings 31Be and 32Be of the first split member 31B and the second split member 32B. The end flange 20B in the present embodiment is constituted by an annular protrusion 20Ba integrally formed at the end of the branch pipe 21B. By sandwiching these annular protrusions 20Ba and the end portion of the branch pipe 21B between the above-described annular protrusions 20Ba and the water pipe W, while allowing slight movement of the branch pipe 21B, coming off and falling are prevented.

[0079] On the water pipe W side of the annular protrusion 20Ba (end flange 20B) of the branch pipe 21B in the present embodiment, a notch 27, for example, in a semicircular shape, is formed at a portion adjacent to the perforation opening Wa. This notch 27 faces upward when the branch pipe forming device 100B is rotated 90 degrees clockwise, and is configured such that the water flowing out from the perforation opening Wa smoothly flows into the branch pipe 21B. Further, since the tip surface of the branch pipe 21B is configured to abut against the water pipe W at the main pipe abutting portion 21Ba, it becomes possible to bring the shut-off valve V closer to the split T-shaped pipe 3B. If this shut-off valve V is made simple, the entire branch pipe forming device 100B becomes extremely compact.

[0080] The branch pipe forming method in the present embodiment includes a branch pipe forming device mounting step, a perforation step, a device rotation step, and a branch pipe water flow step, which are the same as those in the first embodiment, but detailed descriptions thereof are omitted. Further, other operational effects are the same as those in the second embodiment.

[0081] [Fourth Embodiment] As shown in FIGS. 12 to 14, the branch pipe forming device 100C includes a split T-shaped pipe 3C having a split structure, a branch pipe portion 2C connected to the split T-shaped pipe 3C, and a plug 6 made of an elastic member such as rubber that functions as a flow path closing member after perforation.

[0082] The split T-shaped pipe 3C is composed of a first split member 31C and a second split member 32C, and has the same configuration as the split T-shaped pipe 3 according to the first embodiment, so detailed descriptions thereof are omitted. Note that the split T-shaped pipe 3C in the present embodiment has a receiving port shape in which the connecting flange portion 32Cf is integrally formed with the connecting opening portion 32Ce. Further, the branch pipe portion 2C may have the same insertion port shape as the branch pipe portion 2 in the first embodiment, or may simply be configured to include only the branch pipe 21C inside the shut-off valve V.

[0083] The plug 6 is a closing member that is inserted into and closes the connecting opening portion 32Ce of the split T-shaped pipe 3C. The plug 6 has an engaging concave portion 61 that engages with an annular convex portion 32Ce1 formed on the inner peripheral surface of the connecting opening portion 32Ce so as to be in close contact with the connection portion between the bulging portions 31c, 32c and the connecting opening portion 32Ce.

[0084] The method for forming a branch pipe in this embodiment includes a branch pipe forming apparatus mounting step, a punching step, an apparatus rotating step, and a branch pipe water passing step, which are the same as those in the first embodiment. Detailed descriptions thereof are omitted. In this embodiment, between the punching step and the apparatus rotating step, a plug 6 is inserted into the connecting opening 32Ce of the split T-shaped pipe 3C. As a result, it becomes possible to omit the shut-off valve V of the branch pipe portion 2C when the split T-shaped pipe 3C rotates, so that construction can be carried out without interference even if there are obstacles in the branch direction (see FIGS. 13 to 14). Further, at the time of punching, a small punching machine with a small punching stroke can also be used by using a simple thin working valve (shut-off valve V). Other operational effects are the same as those in the first embodiment.

[0085] [Fifth Embodiment] As shown in FIGS. 15 and 19, the branch pipe forming apparatus 100D includes a split T-shaped pipe 3D having a split structure and a branch pipe portion 2D connected to the split T-shaped pipe 3D. The branch pipe forming apparatus 100D in this embodiment is used in a half-cut method for cutting a part of the water pipe W in the vertical direction.

[0086] The split T-shaped pipe 3D is formed of a plurality of (two in this embodiment) connected split housings and covers the water pipe W in a sealed state. This split T-shaped pipe 3D has split surfaces 31Da and 32Da parallel to the plane including the axis X of the water pipe W and the axis Y of the branch pipe 21D, and is composed of a first split member 31D and a second split member 32D that are connected to each other in a sealed state by an annular seal member 35 disposed between these split surfaces 31Da and 32Da.

[0087] In a state where the punching machine 1 is mounted on the branch pipe forming apparatus 100D, it is mounted along the outer peripheral surface of the water pipe W such that the first split member 31D is disposed on the left side and the second split member 32D is disposed on the right side, and the first split surface 31Da of the first split member 31D and the second split surface 32Da of the second split member 32D are along a vertical plane perpendicular to the ground (see FIG. 15).

[0088] The first split member 31D is composed of a cylindrical member, and includes a first main body portion 31Db formed with a hole portion 31Db1 that surrounds approximately half of the water pipe W, a bulging portion 31Dc that protrudes outward (opposite to the water pipe W) from the first main body portion 31Db, a first flange portion (not shown) that extends outward from the first main body portion 31Db, a connection opening portion 31De that protrudes from the first main body portion 31Db and the bulging portion 31Dc toward the branch pipe portion 2D, and a connection flange portion 31Df that protrudes annularly outward from the connection opening portion 31De.

[0089] Inside the first split member 31D, a guide member 4 for guiding the center drill 12 of the drilling machine 1 is disposed. The axis of the hole saw 11 of the drilling machine 1 in the present embodiment is the same as the axis Y of the branch pipe portion 2 and is located outside the outer surface of the water pipe W. The guide member 4 has a guide cylinder 42 into which the center drill 12 is inserted and a support portion 41 that supports the guide cylinder 42.

[0090] The bulging portion 31Dc is located on one side with respect to the axis X of the water pipe W, on the left side with respect to the axis X of the water pipe W during drilling (the state in FIG. 15), and on the lower side with respect to the axis X of the water pipe W when the split T-shaped pipe 3D is rotated 90 degrees clockwise (the state in FIG. 19). Also, when the branch pipe forming device 100D is rotated 90 degrees clockwise, the bulging portion 31Dc faces a part of the perforation opening Wa, and a flow space SD through which water can flow is formed inside the bulging portion 31Dc. The bulging portion 31Dc has a bottom wall 31Dc1 located on the opposite side of the branch pipe portion 2D, and a side wall 31Dc2 standing vertically from the bottom wall 31Dc1. A through hole 31Dc3 through which water can be discharged is formed in this bottom wall 31Dc1, and a support portion 41 or a plug Pd is attached to this through hole 31Dc3. This bulging portion 31Dc faces a region smaller than the semi-circular region divided by a line segment (diameter) including the center of the water pipe W among the outer periphery of the water pipe W. As the formation range of the bulging portion 31Dc, the central angle θ of the water pipe W is 90 degrees or more and less than 180 degrees with respect to the outer periphery of the water pipe W, preferably 150 degrees or more and less than 180 degrees, and more preferably 160 degrees or more and 170 degrees or less. This central angle θ is set so that the flow space SD faces across the perforation opening Wa when the branch pipe forming device 100D is rotated 90 degrees clockwise according to the size of the perforation opening Wa.

[0091] A plurality of first through hole portions (not shown) into which bolts Ba are inserted are formed along a direction perpendicular to the axis Y in a state where the first flange portion faces the second flange portion 32Dd of the second split member 32D. The connection opening 31De is formed in the first split member 31B and has a shut-off valve Ve. The connection flange portion 32Df is connected to the end flange 22D on one side of the branch pipe portion 2D by bolts 23 and nuts 24.

[0092] The second split member 32D is composed of a half split member and has a semi-cylindrical second main body portion 32Db along the outer peripheral surface of the water pipe W, and a second flange portion 32Dd extending outward from the second main body portion 32Db.

[0093] The second main body portion 32Db is curved along the outer peripheral surface of the water pipe W. The second flange portion 32Dd has a plurality of second through-hole portions (not shown) into which the bolt Ba is inserted in a state facing the first flange portion 31Dd, and these are formed along a direction perpendicular to the axis Y. A nut Bb screwed onto this bolt Ba is disposed on the outer surface. Further, the second main body portion 32Db has a plurality of block portions (not shown, similar to the second embodiment) into which a push bolt (not shown, similar to the second embodiment) whose tip abuts against the outer peripheral surface of the water pipe W is inserted, and these project outward.

[0094] The guide cylinder 42 is formed with a protruding portion 42a that abuts against the lower part of the cut portion (section) when the perforation hole Wa is formed in the side surface of the water pipe W, and a holding portion 42b that fits into an annular recess 31Dc4 formed in the bottom wall 31Dc1 of the bulging portion 31Dc and holds the posture of the guide cylinder 42. Further, the guide cylinder 42 is formed with a convex portion 42c that projects further downward than the holding portion 42b, and this convex portion 42c fits into a support portion 41 attached to the through-hole 31Dc3 of the bottom wall 31Dc1 and is position-fixed. Furthermore, on the inner peripheral surface of the guide cylinder 42, an engaging step portion 42d with which the engaging member 12a1 of the center drill 12 can engage is formed.

[0095] Subsequently, with reference to FIGS. 15 to 19, a method for forming a branch pipe using the branch pipe forming device 100D will be described. In the present embodiment, by attaching the branch pipe forming device 100D to a predetermined portion of the water pipe W, a branch pipe 21D to be communicated with the water pipe W is formed, and after perforation, the split T-shaped pipe 3D is rotated 90 degrees clockwise, and the perforation hole Wa and the branch pipe 21D are communicated via the flow space SD.

[0096] The method for forming a branch pipe in the present embodiment includes (1) a step of attaching a branch pipe forming device, (2) a perforation step, (3) a device rotation step, and (4) a step of passing water through the branch pipe.

[0097] (1) Step of attaching a branch pipe forming device As shown in FIG. 15, after excavating around the water pipe W, the first split member 31D and the second split member 32D are arranged on the water pipe W such that the cut surface 31Da of the first split member 31D and the cut surface 32Da of the second split member 32D are along the plane (vertical direction) including the axis X of the water pipe W and the axis Y of the branch pipe 21.

[0098] Specifically, first, the first split member 31D is arranged on the left side of the water pipe W so that a part of the water pipe W is inserted into the hole 31Db1 of the first split member 31D. If there is a pedestal capable of maintaining the first split member 31D in a horizontal state, the first split member 31D may be arranged on this pedestal. Next, the guide cylinder 42 is inserted through the connection opening 31De of the first split member 31D, the holding portion 42b is inserted into the annular recess 31Dc4 so that the protruding portion 42a abuts against the lower part of the water pipe W, and the support portion 41 is attached to the through hole 31Dc3 and fitted to the convex portion 42c, thereby fixing the guide cylinder 42 to the first split member 31D. Alternatively, the first split member 31D with the guide member 4 fixed thereto in advance may be attached by approaching it from the left side of the water pipe W.

[0099] The second split member 32D is brought close to the right side of the first split member 31D, and the cut surface 31Da of the first split member 31D and the cut surface 32Da of the second split member 32D are opposed to each other. Then, the first split member 31D and the second split member 32D are connected in a sealed state by the fastening member B. By the fastening operation with this fastening member B, the annular seal member 35 fitted to the first cut surface 31Da and the annular seal member 35 fitted to the second cut surface 32Da are pressed against each other, thereby sealing the gap between the first split member 31D and the second split member 32D.

[0100] Next, the connection flange portion 31Df of the first split member 31D and the end flange 22D on one side of the branch pipe portion 2D are opposed to each other and connected by bolts 23 and nuts 24. This step of attaching the branch pipe forming device includes a hydrostatic test step of supplying water into the first split member 31D and the second split member 32D to perform a sealing test, which is the same as in the first embodiment and will not be described here.

[0101] (2) Drilling step As shown in FIG. 16, the drilling process includes a drill mounting process of mounting a drill 1 on the branch pipe portion 2D, a drill hole forming process of moving the hole saw 11 of the drill 1 to the cutter accommodation space Sp formed in the first dividing member 31D to form a drill hole Wa at a position adjacent to the cutter accommodation space Sp, and a branch flow path closing process of closing the partition valve Ve provided in the first dividing member 31D.

[0102] In the drill mounting process, the drilling flange 14a of the drill case 14 is fixed to the end flange 25D on the other side of the branch pipe portion 2D with bolts and nuts, and the drill 1 is mounted on the branch pipe portion 2D. In the drill hole forming process, when the hole saw 11 and the center drill 12 are rotated and advanced downward by the rotary drive mechanism 13, while the center drill 12 is guided by the guide cylinder 42, a part (side surface) of the outer peripheral surface of the water pipe W is cut by the cutting tip 11a of the hole saw 11, and the drill hole Wa is formed. At this time, since the hole saw 11 rotates inside the first dividing member 31D, the vibration of the drill 1 does not directly act on the split surfaces 31Da and 32Da, and the deviation of the cutter axis during the drilling operation is small. Then, the engaging member 12a1 of the center drill 12 engages with the engaging step portion 42d of the guide cylinder 42, and the center drill 12 and the guide cylinder 42 are integrated. Next, when a plug Pd is mounted in the through hole 31Dc3 instead of the support portion 41 and the hole saw 11 and the center drill 12 are retracted by the rotary drive mechanism 13, the cut portion (slice) supported by the protruding portion 42a of the guide cylinder 42 can be pulled up together with the guide cylinder 42 (see FIG. 17). That is, the cut portion (slice) generated by the formation of the drill hole Wa is held by the protruding portion 42a of the guide cylinder 42 and is recovered into the branch pipe 21D by retracting the hole saw 11 and the center drill 12 upward.

[0103] In the branch flow path closing process, by closing the partition valve Ve provided in the first dividing member 31D, water leakage from the water pipe W through the drill hole Wa formed in the drill hole forming process is prevented. After the branch flow path closing process, the drill 1 is removed. In this embodiment, since the partition valve Ve is provided in the first dividing member 31D, the branch pipe portion 2D is also removed together with the drill 1.

[0104] (3) Device rotation process As shown in FIG. 18, in the device rotation process, the split T-shaped pipe 3D is rotated by a predetermined angle (90 degrees counterclockwise in this embodiment), and the bulging portion 31Dc is opposed to a part of the perforation opening Wa. Thereby, the communication between the first split member 31D and the perforation opening Wa is maintained. After connecting a pipe to the connection flange portion 31Df of the first split member 31D, by opening the shut-off valve Ve, the flow path of the water pipe W can be switched.

[0105] The branch pipe forming device 100D of this embodiment includes a split T-shaped pipe 3D that covers the water pipe W, and a branch pipe portion 2D having a branch pipe 21D connected to the split T-shaped pipe 3D, and is provided with a shut-off valve Ve capable of closing the flow path in the split T-shaped pipe 3D. In this split T-shaped pipe 3D, when the split T-shaped pipe 3D is rotated while maintaining communication with the perforation opening Wa, a bulging portion 31Dc facing the perforation opening Wa is formed to protrude outward, and the formation range of this bulging portion 31Dc is not restricted by the shut-off valve Ve.

[0106] Further, since the bulging portion 31Dc faces a region smaller than the semi-circular region divided by the line segment including the center of the water pipe W on the outer periphery of the water pipe W, the branch pipe forming device 100D can be made compact. Furthermore, since the bulging portion 31Dc is opposed to a region smaller than the semi-circular region of the water pipe W, when the split T-shaped pipe 3D is rotated, the possibility that the bulging portion 31Dc interferes with other structures is also reduced, and the excavation range can be minimized, so the working efficiency is increased.

[0107] (4) Branch pipe water flow process As shown in Fig. 19, in the branch pipe water flow process, after connecting a new branch pipe part 5D different from the branch pipe part 2D or the same branch pipe part 2D to the connection flange part 31Df of the first dividing member 31D to form a branch flow path, the partition valve Ve of the branch pipe forming device 100D is opened to allow water to flow through the branch pipe part 5D. In the present embodiment, since the bulging part 31Dc is located only on the lower side with respect to the axial center X of the water pipe W when the branch pipe forming device 100D is rotated 90 degrees clockwise, a smooth flow path (flow space SD) leading to the connection opening 32De of the split T-shaped pipe 3D can be formed. That is, compared with the case where the bulging part 31Dc is formed up to above the connection opening 32De, a water accumulation part is not formed, and the pressure loss associated with the flow path switching can be reduced.

[0108] [Other Embodiments] (1) The above-described embodiments can be combined as appropriate. For example, the partition valve Ve of the fourth embodiment may be provided in the branch pipe parts 2D and 5D like the partition valve V of the first embodiment. (2) The split T-shaped pipes 3, 3A, 3B, 3C, and 3D in the above-described embodiments are not limited to being divided into two parts, and may be configured with three or more parts. (3) The existing pipe in the above-described embodiments is not limited to the water pipe W, and may be other fluid pipes.

Industrial Applicability

[0109] The present invention can be used for a branch pipe forming device that is attached to an existing pipe to form a branch pipe that communicates with a perforation formed by perforating the existing pipe with a perforator in a non-stop flow state.

Explanation of Reference Numerals

[0110] 2: Branch pipe part 21: Branch pipe 22: End flange 3: Split T-shaped pipe 31Ae: Connection opening 31c: Bulging part 31c1: Bottom wall 32f: Connection flange part 33: Push bolt P: Plug W: Water pipe (existing pipe) Wa: Perforation X: Axis (center of existing pipe) Y: Axis of branch pipe section 100: Branch pipe forming device

Claims

1. A branch pipe forming device attached to an existing pipe for forming a branch pipe that communicates with a perforation formed by perforating the existing pipe with a perforator in a non-stop flow state, comprising a split T-shaped pipe formed by two connected split housings and covering the existing pipe, and a branch pipe portion having the branch pipe connected to the split T-shaped pipe. The two split housings are split along the axis of the branch pipe portion. The split T-shaped pipe is formed with a bulging portion that protrudes outward and faces the perforation when the split T-shaped pipe is rotated while maintaining communication with the perforation. The bulging portion faces a region smaller than a semi-circular region divided by a line segment including the center of the existing pipe on the outer periphery of the existing pipe. The branch pipe forming device.

2. The branch pipe forming device according to claim 1, wherein the split T-shaped pipe has a connecting opening portion that sandwiches the end portion of the branch pipe portion in a sealed state.

3. A branch pipe forming device attached to an existing pipe for forming a branch pipe that communicates with a perforation formed by perforating the existing pipe with a perforator in a non-stop flow state, comprising a split T-shaped pipe formed by two connected split housings and covering the existing pipe, and a branch pipe portion having the branch pipe connected to the split T-shaped pipe. The two split housings are split in a direction perpendicular to the axis of the branch pipe portion. The split T-shaped pipe is formed with a bulging portion that protrudes outward and faces the perforation when the split T-shaped pipe is rotated while maintaining communication with the perforation. The bulging portion faces a region smaller than a semi-circular region divided by a line segment including the center of the existing pipe on the outer periphery of the existing pipe. The bulging portion is formed across the two split housings. The branch pipe forming device.

4. The branch pipe forming device according to claim 3, wherein the split T-shaped pipe has a connecting flange portion connected to the end flange of the branch pipe portion.

5. On the existing pipe side of the branch pipe portion in the direction along the axis of the branch pipe portion, the split T-shaped pipe is connected, In the direction along the axis of the branch pipe portion, a through hole through which fluid can be discharged is formed in the bottom wall of the bulging portion located on the side opposite to the branch pipe portion, and a plug is attached to the through hole. The branch pipe forming device according to any one of claims 1 to 4.

6. The branch pipe forming device according to any one of claims 1 to 5, wherein a push bolt that can abut against the outer peripheral surface of the existing pipe is screwed into the split T-shaped pipe.

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