Method for forming branch part of fluid pipe, and structure for forming branch part of fluid pipe

Abstract

To reduce a size and a weight of a boring machine.SOLUTION: A branch part 2 is provided with a first split body 3 and a second split body 4. The first split body 3 has a straight pipe portion 34, and the second split body 4 has a connection portion 41 and a branch part formation portion 42. Length in an extension direction of the first split body 3 in a form to secure a space for arranging the branch part formation portion is set to second setting length L2, and length of the straight pipe portion 34 of the first split body 3 is set to first setting length L1 shorter than the second setting length L2. A boring step of arranging the straight pipe portion 34 of the first split body 3 at an outer periphery of a fluid pipe 1 and boring a through hole on the fluid pipe 1 with a boring machine through the straight pipe portion 34, a first blocking step of blocking the first split body 3 with a first blocking member, and a connection step of connecting the first split body 3 to the second split body 4 are performed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for forming a branch portion in a fluid pipe, and a structure for forming a branch portion in a fluid pipe. [Background technology]

[0002] Conventionally, there have been known branch section forming methods and structures for forming a branch section in a fluid pipe, such as a water pipe, by connecting, for example, a T-shaped branch pipe to the fluid pipe (see, for example, Patent Document 1). The T-shaped branch pipe has a straight upstream section extending in a direction perpendicular to the axial direction of the fluid pipe, and a straight downstream section extending from a midpoint of the straight upstream section in a direction perpendicular to the extension direction of the upstream section.

[0003] In this branch section formation structure, the approach side open end of the upstream part of the T-shaped branch pipe is connected to the fluid pipe, and the remote side open end of the upstream part is blocked with a blocking member, so that the fluid can be branched from the fluid pipe to the downstream part of the branch pipe through a through hole drilled in the fluid pipe. The open end of the downstream part of the branch pipe can be connected to various members, such as a branch fluid pipe that carries the branched fluid and a valve device for controlling the flow state of the branched fluid.

[0004] The branch section forming method of Patent Document 1 includes a drilling step in which a branch pipe is installed on the outer periphery of a fluid pipe and a through hole is drilled in the fluid pipe using a drilling machine through a straight upstream section of the branch pipe, and a blocking step in which the open end on the separated side of the upstream section of the branch pipe is blocked with a blocking member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Jpn. Jpn. Published No. 49-8393 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, when performing the drilling process, a drilling machine is installed at the separated open end of the upstream portion of the branch pipe, and a drilling device of the drilling machine is moved through the straight upstream portion to drill a through hole in the fluid pipe.

[0007] Since the T-shaped branch pipe has not only an upstream section but also a downstream section, the length of the upstream section needs to be longer than at least the installation length for installing the downstream section (e.g., the outer diameter of the downstream section). Therefore, the separated side open end of the upstream section, which is the installation position of the drilling machine, is located away from the outer periphery of the fluid pipe. Therefore, the stroke for moving the drilling device of the drilling machine becomes longer, and the driving force applied to the drilling device to drill a through hole in the fluid pipe must also be increased, which leads to an increase in the size and weight of the drilling machine.

[0008] In view of this situation, the main object of the present invention is to provide a method for forming a branching portion of a fluid pipe, and a structure for forming a branching portion of a fluid pipe, which can reduce the size and weight of the drilling machine. [Means for solving the problem]

[0009] A first characteristic configuration of the present invention is a method for forming a branch portion in a fluid pipe, comprising the steps of: The branch portion includes a first divided body and a second divided body, the first division body has a straight pipe portion that is freely connectable to an outer periphery of the fluid pipe and extends in a direction perpendicular to the axial direction of the fluid pipe, the second division body has a connection portion connectable to the first division body and a branch portion forming portion extending in a direction intersecting the extension direction of the first division body, and the length of the first division body in the extension direction is set to a second set length in a form that ensures a space for arranging the branch portion forming portion in the extension direction of the first division body, A length of a straight pipe portion in the first division body is set to a first set length that is shorter than a second set length of the second division body, a drilling step of installing a straight pipe portion of a first division body on an outer periphery of the fluid pipe and drilling a through hole in the fluid pipe by a drilling machine through the straight pipe portion of the first division body; a first closing step of closing the first divided body with a first closing member; and a connecting step of connecting the second divided body to the first divided body.

[0010] According to this configuration, by performing the drilling step, a through hole can be drilled in the fluid pipe by a drilling machine through the straight pipe portion of the first divider installed on the outer periphery of the fluid pipe. By performing the first closing step, the first divider is closed with the first closing member to prevent the fluid from flowing out from the first divider, so that the connecting step of connecting the second divider to the first divider can be performed efficiently and smoothly. In this way, by performing the drilling step, the first closing step, and the connecting step in sequence, in an uninterrupted flow state (uninterrupted water state), the first divider can be installed in the fluid pipe and the second divider can be connected to the first divider to form a branching section by the first divider and the second divider, and the fluid in the fluid pipe can be branched to the branching section formed from the through hole.

[0011] Moreover, in the drilling step, a through hole is drilled in the fluid pipe by moving a drilling device of the drilling machine through the straight pipe portion of the first segment, and the length of the straight pipe portion of the first segment is set to a first set length that is shorter than the second set length of the second segment. This shortens the stroke for moving the drilling device and prevents the driving force applied to the drilling device for drilling a through hole in the fluid pipe from becoming large, thereby making it possible to reduce the size and weight of the drilling machine.

[0012] In a second characteristic configuration of the present invention, the second division body has an upstream pipe section that is freely connectable to a straight pipe section of the first division body and extends in an extending direction of the first division body, and a downstream pipe section that extends from a middle section of the upstream pipe section in a direction intersecting the extending direction of the first division body, The upstream pipe section is provided as the connection section, and the downstream pipe section is provided as the branch section forming section, After the connecting step is performed, a first blocking member blocking the first division is removed, and a second blocking step is performed in which the separated side open end of the upstream pipe portion of the second division that is away from the fluid pipe is blocked with a second blocking member.

[0013] According to this configuration, after the connecting step, the second blocking step is performed, in which the first blocking member is removed and the remote open end of the upstream pipe section of the second split pipe is blocked with the second blocking member, so that the fluid in the fluid pipe flows sequentially from the through hole of the fluid pipe into the first split body and the second split body, and the fluid can be appropriately branched from the fluid pipe to the downstream pipe section of the second split body.

[0014] The downstream pipe portion of the second divided body is provided as a branch portion forming portion, and various components can be connected to the downstream pipe portion, such as a branch fluid pipe for passing the branched fluid, a valve device for controlling the flow state of the branched fluid, etc. Thus, the branch portion can be formed as a branch pipe for passing the fluid branched from the fluid pipe to a desired location, or as a branch flow state control portion for controlling the flow state of the fluid branched from the fluid pipe.

[0015] A third characteristic configuration of the present invention is that the fluid pipe is buried in the ground with an axial direction of the fluid pipe aligned horizontally, In the drilling process, a straight pipe portion of the first divided body is placed on the upper part of the outer periphery of the fluid pipe, and the drilling direction for drilling a through hole in the fluid pipe with a drilling machine is set in a direction from the upper side to the lower side of the fluid pipe.

[0016] In the drilling step, for example, a straight pipe portion of the first segment is placed on a lateral side of the outer periphery of the fluid pipe, and the drilling direction for drilling through holes in the fluid pipe with a drilling machine is set to a direction horizontal to the fluid pipe, so that through holes can be drilled in the lateral direction. However, in this case, it is necessary to secure space for installing the first segment, the drilling machine, etc., and space for performing the installation work for them, on the lateral side of the fluid pipe, so that the excavation range becomes large, which leads to the complication of the work and the increase in costs.

[0017] Therefore, according to this configuration, in the drilling step, the straight pipe portion of the first segment is placed on the upper part of the outer periphery of the fluid pipe, and the drilling direction for drilling through holes in the fluid pipe with the drilling machine is set to a direction from the upper side to the lower side of the fluid pipe, and the through holes are drilled vertically. This makes it possible to secure space for installing the first segment, the drilling machine, etc., and space for performing the installation work for installing them, and there is no need to secure such space on the lateral parts of the fluid pipe, making it possible to reduce the excavation range, simplifying the work, and reducing costs.

[0018] A fourth characteristic configuration of the present invention is that the first closing member is provided as a dual-purpose closing member that also serves as the second closing member, In the second blocking process, a dual-purpose blocking member serving as a first blocking member arranged at a first blocking position blocking the distal open end of the straight pipe section in the first partition is moved to a second blocking position blocking the distal open end of the upstream pipe section in the second partition, thereby blocking the distal open end of the upstream pipe section in the second partition with the dual-purpose blocking member.

[0019] According to this configuration, the first and second closing members are provided in one combined closing member, so that the configuration can be simplified and the cost can be reduced. Moreover, when the combined closing member serves as both the first and second closing members, in the second closing step, it is only necessary to move the combined closing member disposed at the first closing position to the second closing position, so that the work of the second closing step can also be simplified.

[0020] A fifth characteristic configuration of the present invention is a first position holding portion for holding the dual-purpose blocking member at the first blocking position, The second closing position is provided with a second position holding portion for holding the combination closing member in the second closing position.

[0021] According to this configuration, not only can the combined blocking member be appropriately held in the first blocking position by the first position holding part when the combined blocking member is placed in the first blocking position, but also can the combined blocking member be appropriately held in the second blocking position by the second position holding part when the combined blocking member is placed in the second blocking position. This makes it possible to perform the work of forming the branching part while appropriately preventing the outflow of fluid to the outside in an uninterrupted flow state (uninterrupted water supply state).

[0022] A sixth characteristic configuration of the present invention is such that the first position holding portion is provided with a first restricting portion that allows movement of the dual-purpose blocking member on a side away from the fluid pipe and restricts movement of the dual-purpose blocking member on a side approaching the fluid pipe by contacting the dual-purpose blocking member, The second position maintaining portion is characterized in that it allows movement of the dual-purpose closure member toward the fluid pipe and is provided with a second regulating portion that abuts against the dual-purpose closure member plug and regulates movement away from the fluid pipe.

[0023] Comparing the first blocking position for blocking the remote-side open end of the straight pipe section in the first division with the second blocking position for blocking the remote-side open end of the upstream pipe section in the second division, the first blocking position is located closer to the fluid pipe than the second blocking position. Therefore, when the dual-purpose blocking member disposed at the first blocking position is moved to the second blocking position in the second blocking step, the dual-purpose blocking member is moved away from the fluid pipe.

[0024] Therefore, according to this configuration, the first restricting portion restricts the movement of the dual-purpose blocking member on the side approaching the fluid pipe by contacting the dual-purpose blocking member, while allowing the movement of the dual-purpose blocking member on the side away from the fluid pipe. Therefore, the dual-purpose blocking member can be appropriately moved from the first blocking position to the side away from the fluid pipe while preventing the dual-purpose blocking member from moving from the first blocking position to the side approaching the fluid pipe. In contrast, the second restricting portion allows the movement of the dual-purpose blocking member on the side approaching the fluid pipe, so that the dual-purpose blocking member that has moved from the first blocking position to the side away from the fluid pipe can be appropriately moved to the second blocking position. Moreover, since the second restricting portion restricts the movement of the dual-purpose blocking member on the side away from the fluid pipe by contacting the dual-purpose blocking member, the second restricting portion can abut against the dual-purpose blocking member that has reached the second blocking position by moving away from the fluid pipe, and can appropriately hold the dual-purpose blocking member in the second blocking position. In this manner, in the second closing step, the task of moving the dual-purpose closing member disposed at the first closing position to the second closing position can be performed efficiently and appropriately.

[0025] A seventh characteristic configuration of the present invention is a branch forming structure for a fluid pipe, which forms a branch portion in a fluid pipe, The branch portion includes a first divided body and a second divided body, the first division body has a straight pipe portion that is freely connectable to an outer periphery of the fluid pipe and extends in a direction perpendicular to the axial direction of the fluid pipe, the second division body has a connection portion connectable to the first division body and a branch portion forming portion extending in a direction perpendicular to the extension direction of the first division body, and the length of the first division body in the extension direction is set to a second set length in a form that ensures a space for arranging the branch portion forming portion in the extension direction of the first division body, The length of the straight pipe portion in the first divided body is set to a first set length that is shorter than a second set length of the second divided body.

[0026] According to this configuration, when drilling a through hole in a fluid pipe with a drilling machine, a straight pipe portion of the first division is placed on the outer periphery of the fluid pipe, and a drilling device of the drilling machine is moved through the straight pipe portion of the first division to drill a through hole in the fluid pipe. When connecting the second division to the first division, the first division is blocked by the first blocking member, so that the connection work of connecting the second division to the first division can be performed efficiently and smoothly while preventing the outflow of fluid to the outside. In this way, in an uninterrupted flow state (uninterrupted water state), the first division is placed on the fluid pipe, and the second division is connected to the first division to form a branch portion by the first division and the second division, and the fluid in the fluid pipe can be branched to the branch portion formed from the through hole.

[0027] Since the length of the straight pipe portion in the first segment is set to a first set length that is shorter than the second set length of the second segment, when the drilling device of the drilling machine is moved through the straight pipe portion of the first segment, the stroke for moving the drilling device is shortened and it is possible to prevent the driving force applied to the drilling device for drilling a through hole in the fluid pipe from becoming large, thereby making it possible to reduce the size and weight of the drilling machine. [Brief description of the drawings]

[0028] [Figure 1] FIG. 2 is a side view showing the fluid pipe and the branching portion as viewed from a direction perpendicular to the axial direction of the fluid pipe; [Diagram 2] FIG. 2 is a front view showing the fluid pipe and the branching portion as viewed from the axial direction of the fluid pipe; [Diagram 3] Diagram showing the drilling process [Figure 4] A diagram showing the first closing step [Diagram 5] FIG. 13 is a diagram showing a state in which the working valve is removed in the first closing step. [Figure 6] A diagram showing how a water pressure test is performed during the connection process. [Figure 7] FIG. 13 is a diagram showing a state in which the adapter is connected to the dual-purpose blocking member in the second blocking step. [Figure 8]A diagram showing the process of assembling the insertion machine in the second closing process. [Figure 9] FIG. 13 is a view showing a state in which the dual-purpose blocking member is disposed at the first blocking position in the second blocking step. [Figure 10] FIG. 13 is a view showing a state in which the dual-purpose blocking member is moved to the second blocking position in the second blocking step. [Figure 11] Diagram showing the flange lid installation process [Figure 12] FIG. 1 shows an insertion machine and a combination blocking member. [Figure 13] FIG. 13 is a diagram showing a first blocking position and a second blocking position for a dual-purpose blocking member; [Figure 14] Enlarged portion of the first divided body and the dual-purpose blocking member in the first blocking position [Figure 15] FIG. 13 is an enlarged view of the second divided body and the dual-purpose blocking member in the second blocking position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for forming a branched portion of a fluid pipe and a structure for forming a branched portion of a fluid pipe according to the present invention will be described with reference to the drawings. 1 and 2, this branch portion forming method is a method for forming a branch portion 2 in a fluid pipe 1. In this branch portion forming method, a branch portion forming structure for forming the branch portion 2 in the fluid pipe 1 is adopted.

[0030] The fluid pipe 1 is, for example, an existing water pipe, and is buried underground with the axial direction of the fluid pipe 1 (X direction in FIG. 1) aligned horizontally as shown in Fig. 1. The branch section 2 is provided with a first divided body 3 and a second divided body 4, and the branch section 2 is formed by combining the first divided body 3 and the second divided body 4.

[0031] (1st split body) 1 and 2, the first divided body 3 is divided into a lower portion 31 and an upper portion 32. Although detailed illustration is omitted, the first divided body 3 is installed on the outer periphery of the fluid pipe 1 in a state in which the lower portion 31 and the upper portion 32 are clamped and fixed to the outer periphery of the fluid pipe 1 by fastening a flange portion of the lower portion 31 and a flange portion of the upper portion 32 with fasteners such as bolts and nuts.

[0032] With the first divided body 3 installed on the outer periphery of the fluid pipe 1, as shown in Fig. 1, pressure rings 5 ​​for sealingly fixing the first divided body 3 to the fluid pipe 1 are disposed on both ends of the first divided body 3 in the axial direction of the fluid pipe 1 (X direction in Fig. 1). The pressure rings 5 ​​are connected to both end portions of the first divided body 3 in the axial direction of the fluid pipe 1 using fasteners B such as bolts and nuts. The pressure ring 5 is divided into two, for example, and is tightened and fixed to the outer periphery of the fluid pipe 1 by fastening the divided parts together with fasteners such as bolts and nuts.

[0033] As shown in Fig. 1, the lower portion 31 is provided as a lower covering portion that covers a lower portion of the outer periphery of the fluid pipe 1. As shown in Figs. 1 and 2, the upper portion 32 has an upper covering portion 33 that covers an upper portion of the outer periphery of the fluid pipe 1, and a straight pipe portion 34 that extends from the upper covering portion 33 in a direction perpendicular to the axial direction of the fluid pipe 1 (Y direction in Figs. 1 and 2).

[0034] (Second split body) As shown in Figures 1 and 2, the second division body 4 has an upstream pipe section 41 that is freely connectable to the first division body 3 and extends in the extension direction of the straight pipe section 34 in the first division body 3 (Y direction in Figures 1 and 2), and a downstream pipe section 42 that extends from a midpoint of the upstream pipe section 41 in a direction perpendicular to the extension direction of the straight pipe section 34 in the first division body 3 (Z direction in Figure 2).

[0035] The upstream pipe section 41 is provided as a connection section connectable to the straight pipe section 34 of the first division 3, and is formed into a straight pipe shape extending in the extension direction of the straight pipe section 34 of the first division 3 (Y direction in Figs. 1 and 2) as shown in Figs. 1 and 2. The inner and outer diameters of the upstream pipe section 41 are set to be the same or approximately the same as the inner and outer diameters of the straight pipe section 34 of the first division 3. The first division 3 and the second division 4 are connectable in a sealed state by fastening the flange section 35 of the straight pipe section 34 of the first division 3 to the lower flange section 43 of the upstream pipe section 41 of the second division 4 with fasteners such as bolts and nuts (see Fig. 11, omitted in Figs. 1 and 2).

[0036] 1 and 2, a flange lid portion 6 that closes the upstream pipe portion 41 is disposed at the upper end portion (downstream end portion) of the upstream pipe portion 41. The flange lid portion 6 is fixed to the upper end portion (downstream end portion) of the upstream pipe portion 41 by fastening the flange lid portion 6 and an upper flange portion 44 of the upstream pipe portion 41 with fasteners B such as bolts and nuts.

[0037] 1 and 2, the downstream pipe section 42 has a straight pipe shape extending in a direction perpendicular to the extension direction of the straight pipe section 34 in the first division 3, and is provided integrally with the upstream pipe section 41 by welding or the like. The inner and outer diameters of the downstream pipe section 42 are set to be the same or approximately the same as the inner and outer diameters of both the straight pipe section 34 in the first division 3 and the upstream pipe section 41 in the second division 4.

[0038] 1 and 2, a connecting flange 45 is provided at the downstream end of the downstream pipe section 42 for connecting various members to the branching section 2 formed by the first division 3 and the second division 4. For example, as shown in Fig. 11, a valve device 7 such as a valve can be provided as the various members, and by connecting this valve device 7 to the connecting flange 45, the flow state of the fluid branched off to the branching section 2 can be controlled.

[0039] 1 and 2, the second division 4 is provided with not only an upstream pipe section 41 but also a downstream pipe section 42 branched off from the upstream pipe section 41. The downstream pipe section 42 is provided as a branch section forming section extending in a direction (Z direction in FIG. 2) perpendicular to the extension direction of the straight pipe section 34 in the first division 3. Therefore, the length of the second division 4 in the extension direction of the straight pipe section 34 of the first division 3 is set to a second set length L2 in a form that ensures a space for arranging a branch section forming section (for example, the outer diameter of the downstream pipe section 42) in the extension direction of the straight pipe section 34 of the first division 3 (Y direction in FIGS. 1 and 2).

[0040] On the other hand, the first division 3 has a straight pipe section 34 extending from the outer periphery of the fluid pipe 1 in a direction perpendicular to the axial direction of the fluid pipe 1. The length of the straight pipe section 34 in the extension direction of the first division 3 (Y direction in Figs. 1 and 2) is set to a first set length L1 that is shorter than the second set length L2 of the second division 4, as shown in Figs. 1 and 2. This first set length L1 is, for example, the length from the outer periphery of the fluid pipe 1 to the upper end of the straight pipe section 24 in the vertical direction, and corresponds to the stroke of the drilling machine 21 moving the drilling device in the vertical direction when the drilling machine 21 drills a through hole in the fluid pipe 1.

[0041] In this way, the straight pipe section 34 of the first division 3 is formed in a short pipe shape with a short length in the extension direction of the first division 3, and even the upper end (downstream end) of the straight pipe section 34 has a short distance to the outer periphery of the fluid pipe 1. Therefore, as shown in Fig. 3, by installing the drilling machine 21 on the upper end side of the straight pipe section 34, the drilling device of the drilling machine 21 can be moved through the straight pipe section 34 to drill a through hole in the fluid pipe 1. As a result, the stroke of the drilling device of the drilling machine 21 can be shortened, and the drilling machine 21 can be made smaller and lighter in weight.

[0042] A method for forming a branched portion 2 in the fluid pipe 1 will now be described. This method of forming a split section sequentially involves a drilling process in which a through hole is drilled in the fluid pipe 1 using a drilling machine 21 and an operating valve 11, as shown in Figure 3; a first closing process in which the first split body 3 is blocked with a first blocking member 61a, as shown in Figure 4, using an insertion machine 51; a connecting process in which the second split body 4 is connected to the first split body 3, as shown in Figure 6; and a second closing process in which the second split body 4 is blocked with a second blocking member 61b, as shown in Figure 10, using the insertion machine 51.

[0043] In Figures 3 to 11, the area located to the left of the central dotted line is basically shown as a half cross-section, and various components and devices other than the first division body 3, the second division body 4, and the valve device 7 connected to the second division body 4 are shown by double-dotted dashed lines.

[0044] In this method of forming a split portion, various members and devices such as an operating valve 11, a drilling machine 21, an insertion machine 51, a first closing member 61a, and a second closing member 61b are used, so these various members and devices will first be described.

[0045] (Work valve) 3, the working valve 11 is provided with a valve case 12 housing a valve element that can be opened and closed by operating an operating unit 13. The valve case 12 is attached in a sealed state to the upper end of the straight pipe portion 34 of the first division body 3. Although not shown in the drawings, for example, a flange portion 35 of the straight pipe portion 34 and a connecting portion of the valve case 12 are fastened with fasteners such as bolts and nuts, so that the valve case 12 can be freely connected to the straight pipe portion 34 of the first division body 3 in a sealed state.

[0046] (Drilling machine) 3, the drilling machine 21 is equipped with a drilling device housing section 23 housing a drilling device (not shown) such as a cutter, and a power applying section 22 having a power applying device that applies power for moving and drilling the drilling device. By applying power for moving and drilling the drilling device with the power applying section 22, the drilling machine 21 can perform a moving operation of moving the drilling device close to the fluid pipe 1, and a drilling operation of using the drilling device to drill the outer periphery of the fluid pipe 1 to form a through hole.

[0047] As shown in FIG. 3, a drilling device accommodating section 23 is attached in a sealed state to the valve case 12 of the working valve 11, and a power applying section 22 is attached in a sealed state to the drilling device accommodating section 23. The drilling device accommodating section 23 is formed in a straight tube shape, and a connecting lower flange section 25 is arranged at its lower end, and a connecting upper flange section 26 is arranged at its upper end. The connecting lower flange section 25 of the drilling device accommodating section 23 and the connecting section of the valve case 12 are fastened with fasteners such as bolts and nuts, so that the drilling device accommodating section 23 is connected in a sealed state to the valve case 12. A connecting flange section 24 is arranged at the lower end of the power applying section 22, and the connecting flange section 24 and the connecting upper flange section 26 of the drilling device accommodating section 23 are fastened with fasteners B such as bolts and nuts, so that the power applying section 22 is connected in a sealed state to the drilling device accommodating section 23.

[0048] (insertion machine) As shown in Figures 4 and 12, the insertion machine 51 is equipped with an insertion machine main body 52, an insertion shaft portion 53 for inserting the first blocking member 61a, a support portion 54 that supports the insertion shaft portion 53 so that it can move freely in the insertion direction (up and down direction), a guide portion 55 for guiding the insertion shaft portion 53 so that it can move freely in the insertion direction (up and down direction), and a guided portion 56 that is connected to the insertion shaft portion 53 and guided in the insertion direction (up and down direction) by the guide portion 55.

[0049] 4 and 12, a connecting flange portion 57 that can be freely connected to the valve case 12 of the working valve 11 is disposed at the lower end of the insertion machine body 52. ​​Although detailed illustration is omitted, the connecting flange portion 57 and the connecting portion of the valve case 12 are fastened together using fasteners such as bolts and nuts, so that the insertion machine body 52 can be freely connected to the valve case 12.

[0050] 12, the insertion machine body 52 is formed in a curved shape with its center located at the top and both ends located downward. A cylindrical insertion shaft 53 is disposed in the center of the insertion machine body 52 so as to extend in the vertical direction, and the insertion shaft 53 is supported by a support part 54 so as to be movable in the vertical direction. An insertion machine seal member 59 for sealing between the outer periphery of the insertion shaft 53 and the support part 54 is disposed in the upper and lower parts of the support part 54 which abuts against and supports the insertion shaft 53.

[0051] As shown in Fig. 12, the guide parts 55 are long bolts extending in the vertical direction, and a pair of left and right guide parts 55 are provided in a state in which they are erected upward from the support part 54 and sandwich the insertion shaft part 53. The guided part 56 is disposed at the upper end of the insertion shaft part 53, and both left and right end parts of the guided part 56 are engaged with the pair of left and right guide parts 55. The guided part 56 is guided along the longitudinal direction (vertical direction) of the guide part 55 in a state in which it is engaged with the guide part 55, so that the insertion shaft part 53 can move smoothly in the vertical direction without losing its posture. The insertion shaft part 53 may be inserted partway using a lever hoist.

[0052] As shown in FIG. 12, the lower end of the insertion shaft 53 is provided with an adapter connection part 53a that can be freely connected to an insertion machine side connection part 73 of a cylindrical adapter 71. The adapter connection part 53a of the insertion shaft 53 is formed in a convex shape that protrudes downward, and a threaded part is provided on the outer periphery of the convex part. The insertion machine side connection part 73 of the adapter 71 is formed in a concave shape disposed on the upper end of the adapter 71, and a threaded part is provided on the inner wall part of the concave part. As a result, the convex adapter connection part 53a is engaged with the concave insertion machine side connection part 73, and the threaded part of the adapter connection part 53a and the threaded part of the insertion machine side connection part 73 are screwed together, thereby making it possible for the insertion shaft 53 and the adapter 71 to be freely connected.

[0053] (Blocking member) The blocking members include a first blocking member 61a that blocks the straight pipe section 34 of the first division 3 when positioned at the first blocking position as shown in FIG. 4, and a second blocking member 61b that blocks the upstream pipe section 41 of the second division 4 when positioned at the second blocking position as shown in FIG. 10.

[0054] 12, the first blocking member 61a and the second blocking member 61b are not different but are the same member, and a dual blocking member 61 that serves as both the first blocking member 61a and the second blocking member 61b is provided. The dual blocking member 61 has a ring-shaped outer periphery portion 62 and a central portion 63 located closer to the center than the outer periphery portion 62.

[0055] The outer peripheral portion 62 is formed into a wall shape having a predetermined thickness extending in the vertical direction, as shown in Fig. 12. An engagement groove portion 64 that is recessed inward is formed in the outer wall portion of the outer peripheral portion 62, and an upper recess portion 65 and a lower recess portion 66 for mounting a seal member are formed on the upper and lower sides of the engagement groove portion 64.

[0056] As shown in FIG. 12, the central portion 63 is formed in a curved shape with its central portion located at the lowest position and both ends located upward. An adapter connection portion 67 that can be freely connected to a blocking member side connection portion 72 of an adapter 71 is disposed in the center of the central portion 63. The adapter connection portion 67 is provided with a tip portion 67b as a convex cylindrical portion having a smaller diameter than the base end portion 67a, and a thread portion is formed on the outer periphery of the tip portion 67b. The blocking member side connection portion 72 of the adapter 71 is formed in a concave shape disposed at the lower end of the adapter 71, and a thread portion is formed on the inner wall of the concave portion. As a result, the convex adapter connection portion 67 is engaged with the concave blocking member side connection portion 72, and the thread portion at the tip portion 67b of the adapter connection portion 67 is screwed into the thread portion at the blocking member side connection portion 72, so that the dual-purpose blocking member 61 and the adapter 71 can be freely connected, as shown in FIG. 7.

[0057] (1st position holding part) As shown in Figures 4 and 9, the dual-purpose blocking member 61 is disposed in the first blocking position to block the straight pipe section 34 of the first division body 3. The first blocking position is set at a position corresponding to the upper end (downstream end) of the straight pipe section 34, and the first blocking position is provided with a first position retaining portion 81 for retaining the dual-purpose blocking member 61 at the first blocking position, as shown in Figures 13 and 14. Incidentally, Figure 14 is an enlarged view of the area shown in the half cross section to the left of the central dashed line in Figure 9 in the straight pipe section 34 of the first division body 3.

[0058] As shown in Figures 13 and 14, the first position retaining portion 81 is provided with a first engagement portion 84 that engages with the engagement groove portion 64 of the combination blocking member 61 to retain the combination blocking member 61 in the first blocking position, and a first regulating portion 85 that abuts against the combination blocking member 61 to regulate the movement of the combination blocking member 61.

[0059] 14, a cylindrical first position-retaining member 82 is formed in a first restricting portion 85 provided in the straight pipe portion 34 of the first divided body 3, the first position-retaining member 82 communicating with the inside and outside at a portion corresponding to the first closed position. A first engaging portion 84 is screwed and attached to the inner end portion of the communication hole of the first position-retaining member 82 so as to be freely retractable, with a tip portion of the first engaging portion protruding inward beyond the inner wall portion of the straight pipe portion 34. A first water stop plug 83 is screwed and attached to the outer end portion of the communication hole of the first position-retaining member 82 so as to be freely detachable.

[0060] As shown in Fig. 14, the first restricting portion 85 is provided in an orientation extending in the vertical direction on the inner wall portion of the straight pipe portion 34, and its lower portion is formed in an L-shape protruding inward of the straight pipe portion 34. When the dual-purpose blocking member 61 is arranged in the first blocking position, the outer peripheral portion 62 of the dual-purpose blocking member 61 and the first restricting portion 85 are positioned opposite each other, and the upper surface portion of the lower portion of the first restricting portion 85 is provided as a first abutting portion 86 that abuts against the lower end of the outer peripheral portion 62 of the dual-purpose blocking member 61. As a result, the first restricting portion 85 allows the dual-purpose blocking member 61 to move upward (the side away from the fluid pipe 1), and the first abutting portion 86 abuts against the lower end of the outer peripheral portion 62 of the dual-purpose blocking member 61 to restrict movement downward (the side approaching the fluid pipe 1).

[0061] As shown in Fig. 14, a first position retaining member 82 having a first water stop plug 83 and a first engagement portion 84 is disposed at the center of the first restricting portion 85 in the vertical direction. An upper recess 65 and a lower recess 66 are disposed at the outer peripheral portion 62 of the combined blocking member 61 facing the first restricting portion 85, sandwiching the engagement groove portion 64 in the vertical direction. An upper seal member 87 attached to the upper recess 65 seals between the first restricting portion 85 on the first divided body 3 side and the outer peripheral portion 62 on the combined blocking member 61 side, and a lower seal member 88 attached to the lower recess 66 seals between the first restricting portion 85 on the first divided body 3 side and the outer peripheral portion 62 on the combined blocking member 61 side. As a result, the engagement position where the first engagement portion 84 on the first partition 3 side and the engagement groove portion 64 on the combined blocking member 61 side engage is sealed on both the upper and lower sides in the vertical direction by the upper side sealing member 87 and the lower side sealing member 88.

[0062] As shown in Fig. 14, the sealing member seals not only the upper and lower sides of the engagement position where the first engagement portion 84 on the first division 3 side and the engagement groove portion 64 on the combined blocking member 61 side engage, but also between the straight pipe portion 34 of the first division 3 and various members and devices connected to the straight pipe portion 34. A first recess 111 for mounting a sealing member is formed in the flange portion 35 in the straight pipe portion 34 of the first division 3, and a first sealing member 112 is provided so as to be freely mounted in the first recess 111. In Fig. 14, the upstream pipe portion 41 of the second division 4 is connected to the straight pipe portion 34 of the first division 3, so that the first sealing member 112 mounted in the first recess 111 seals between the flange portion 35 in the straight pipe portion 34 of the first division 3 and the lower flange portion 43 in the upstream pipe portion 41 of the second division 4.

[0063] (Second position holding part) As shown in Fig. 10, the dual-purpose blocking member 61 blocks the upstream pipe section 41 of the second divided body 4 by being disposed in the second blocking position. The second blocking position is set at a position corresponding to the upper end (downstream end) of the upstream pipe section 41, and the second blocking position is provided with a second position retaining portion 91 for retaining the dual-purpose blocking member 61 at the second blocking position, as in the first blocking position, as shown in Figs. 13 and 15. Incidentally, Fig. 15 is an enlarged view of the region shown in the half cross section to the left of the central dashed line in Fig. 10, in the upstream pipe section 41 of the second divided body 4.

[0064] As shown in Figures 13 and 15, the second position retaining portion 91 is provided with a second engagement portion 94 that engages with the engagement groove portion 64 of the combination blocking member 61 to retain the combination blocking member 61 in the second blocking position, and a second regulating portion 95 that abuts against the combination blocking member 61 to regulate the movement of the combination blocking member 61.

[0065] 15, a cylindrical second position-retaining member 92 is formed in the second restricting portion 95 provided in the upstream pipe portion 41 of the second divided body 4, communicating with the inside and outside at a portion corresponding to the second blocking position. A second engaging portion 94 is screwed and attached to the inner end portion of the communication hole of the second position-retaining member 92 so as to be freely retractable, with its tip portion protruding inward beyond the inner wall portion of the upstream pipe portion 41. A second water stop plug 93 is screwed and attached to the outer end portion of the communication hole of the second position-retaining member 92 so as to be freely detachable.

[0066] 15, the second restricting portion 95 is provided in an orientation extending in the vertical direction on the inner wall portion of the upstream pipe portion 41, and its upper portion is formed in an inverted L shape protruding inward of the upstream pipe portion 41. When the dual-purpose blocking member 61 is disposed in the second blocking position, the outer peripheral portion 62 of the dual-purpose blocking member 61 and the second restricting portion 95 are positioned opposite each other, and the lower surface portion of the upper portion of the second restricting portion 95 is provided as a second abutting portion 96 that abuts against the upper end of the outer peripheral portion 62 of the dual-purpose blocking member 61. As a result, the second restricting portion 95 allows the dual-purpose blocking member 61 to move downward (the side approaching the fluid pipe 1), and the second abutting portion 96 abuts against the upper end of the outer peripheral portion 62 of the dual-purpose blocking member 61 to restrict movement upward (the side away from the fluid pipe 1).

[0067] As shown in Fig. 15, a second position retaining member 92 having a second water stop plug 93 and a second engagement portion 94 is disposed at the center of the second restricting portion 95 in the vertical direction. An upper recess 65 and a lower recess 66 are disposed at the outer peripheral portion 62 of the combined blocking member 61 facing the second restricting portion 95, sandwiching an engagement groove portion 64 in the vertical direction. An upper seal member 87 attached to the upper recess 65 seals between the second restricting portion 95 on the second divided body 4 side and the outer peripheral portion 62 on the combined blocking member 61 side, and a lower seal member 88 attached to the lower recess 66 seals between the second restricting portion 95 on the second divided body 4 side and the outer peripheral portion 62 on the combined blocking member 61 side. As a result, the engagement position where the second engagement portion 94 on the second partition 4 side and the engagement groove portion 64 on the combined blocking member 61 side engage is sealed on both the upper and lower sides in the vertical direction by the upper side sealing member 87 and the lower side sealing member 88.

[0068] As shown in Fig. 15, the sealing member seals not only the upper and lower sides of the engagement position where the second engagement portion 94 on the second division 4 side and the engagement groove portion 64 on the combined blocking member 61 side engage, but also between the upstream pipe portion 41 of the second division 4 and various members and devices connected to the upstream pipe portion 41. A second recess 113 for mounting a sealing member is formed in the upper flange portion 44 of the upstream pipe portion 41 of the second division 4, and a second seal member 114 is provided so as to be freely mounted in the second recess 113. In Fig. 15, the insertion machine 51 is connected to the upstream pipe portion 41 of the second division 4, so that the second seal member 114 mounted in the second recess 113 seals between the upper flange portion 44 of the upstream pipe portion 41 of the second division 4 and the connecting flange portion 57 of the insertion machine 51.

[0069] The operations in each of the steps of the branch portion forming method, that is, the drilling step, the first closing step, the connecting step, and the second closing step, will be described below.

[0070] (Drilling process) 3, this drilling process is a process for drilling a through hole in the fluid pipe 1 using a drilling machine 21. Before the drilling process is performed, the first divided body 3 is already installed on the outer periphery of the fluid pipe 1, so when the drilling process is performed, the operation valve 11 is attached to the first divided body 3, and the drilling machine 21 is attached to the operation valve 11.

[0071] In the drilling process, the working valve 11 is switched from a closed state to an open state, and a moving operation is performed in which the drilling device of the drilling machine 21 is moved downward to the fluid pipe 1 through the internal space of the straight pipe portion 34 of the first division 3. When the drilling device of the drilling machine 21 is moved to the fluid pipe 1, a drilling operation is performed in which the drilling device drills the outer periphery of the fluid pipe 1 to form a through hole. In this way, in the drilling process, the straight pipe portion 34 of the first division 3 is placed above the outer periphery of the fluid pipe 1, and the drilling direction in which the drilling machine 21 drills a through hole in the fluid pipe 1 is set to a direction from the upper side toward the lower side of the fluid pipe 1.

[0072] Thereafter, the drilling device of the drilling machine 21, together with the drilled cutting section, etc., is moved upward to its original position through the internal space of the straight pipe section 34 of the first partition 3, the working valve 11 is switched from an open state to a closed state, and the drilling machine 21 is removed from the working valve 11.

[0073] In the drilling process, the drilling device of the drilling machine 21 is moved vertically through the internal space of the straight pipe portion 34 of the first division 3. The length of the straight pipe portion 34 of the first division 3 in the drilling direction (vertical direction) of the drilling machine 21 is set to a first set length L1 that is shorter than the second set length L2 of the second division 4, as shown in Figures 1 and 2. This makes it possible to shorten the stroke for moving the drilling device of the drilling machine 21 vertically, and to reduce the size and weight of the drilling machine 21.

[0074] (1st occlusion step) 4, the first closing step is a step for closing the straight pipe portion 34 of the first division 3 with a first closing member 61a (dual-purpose closing member 61). An insertion machine 51 is attached to the working valve 11 for inserting the first closing member 61a (dual-purpose closing member 61) into the first closing position for closing the straight pipe portion 34 of the first division 3.

[0075] In the first blocking step, as shown in FIG. 4, an insertion machine 51 is attached to the working valve 11, the working valve 11 is switched from a closed state to an open state, and the insertion machine 51 moves the insertion shaft portion 53 downward to move the dual-purpose blocking member 61 downward and insert it into the first blocking position. At this time, as shown by the dotted line in FIG. 4, the communication passage 58 communicated with the inside of the insertion machine main body 52 in the insertion machine 51 is connected to the chip discharge plug 36 arranged in the first divided body 3. As a result, the upper space and the lower space of the dual-purpose blocking member 61 are communicated with each other through the communication passage 58, and the upper space and the lower space of the dual-purpose blocking member 61 are in an equal pressure state. Therefore, in the equal pressure state, the insertion machine 51 can perform an operation to insert the dual-purpose blocking member 61 into the first blocking position, so that the dual-purpose blocking member 61 can be inserted to the first blocking position in a stable posture, and the straight pipe portion 34 of the first divided body 3 can be appropriately blocked by the dual-purpose blocking member 61. Although not shown, an air vent valve is provided above the insertion machine body 52, which allows air to be discharged while communicating to equalize the pressure.

[0076] When inserting the dual-purpose blocking member 61 to the first blocking position by the insertion machine 51, an adapter 71 is connected to the insertion shaft 53 of the insertion machine 51, and the insertion shaft 53 is connected to the dual-purpose blocking member 61 via the adapter 71, as shown in Fig. 4. As a result, even if the insertion length to reach the first blocking position is insufficient with only the insertion shaft 53, by connecting the adapter 71, the dual-purpose blocking member 61 can be properly inserted to the first blocking position.

[0077] As shown in FIG. 14, the first engagement portion 84 that engages with the engagement groove portion 64 in the outer peripheral portion 62 of the dual-purpose blocking member 61 is disposed in the first blocking position, so that the movement of the dual-purpose blocking member 61 to the first blocking position may be hindered by the first engagement portion 84. Therefore, when inserting the dual-purpose blocking member 61 to the first blocking position with the insertion machine 51, the first water stop plug 83 is removed and the first engagement portion 84 is screwed to the disengagement position (the position where the first engagement portion 84 retracts outward and disengages from the engagement groove portion 64). This allows the dual-purpose blocking member 61 to move smoothly to the first blocking position without being hindered by the first engagement portion 84. In addition, when the first engagement portion 84 is inserted, the upper seal member 87 and the lower seal member 88 seal the dual-purpose blocking member 61, so that the fluid does not spurt out to the outside.

[0078] 14, a first restricting portion 85 having a first abutment portion 86 is disposed at the first blocking position. As a result, when the insertion machine 51 moves the dual-purpose blocking member 61 downward and the dual-purpose blocking member 61 reaches the first blocking position, the first abutment portion 86 of the first restricting portion 85 abuts against the dual-purpose blocking member 61, restricting further downward movement of the dual-purpose blocking member 61. Therefore, the dual-purpose blocking member 61 can be appropriately moved downward (inserted) with respect to the first blocking position.

[0079] 14, when the combined blocking member 61 is inserted into the first blocking position, the first engaging portion 84 is screwed into the engaging position (the position where the first engaging portion 84 protrudes inward and engages with the engaging groove portion 64), and then the first water stop plug 83 is attached, so that the first engaging portion 84 engages with the engaging groove portion 64 on the combined blocking member 61 side. Therefore, the combined blocking member 61 arranged in the first blocking position is held in the first blocking position by the engagement between the first engaging portion 84 and the engaging groove portion 64, and by the abutment between the first abutment portion 86 of the first restricting portion 85 and the combined blocking member 61.

[0080] When the upper end (downstream end) of the straight pipe portion 34 of the first division 3 is blocked by the dual-purpose blocking member 61, the operation valve 11 is removed from the first division 3 as shown in FIG.

[0081] (Connection process) This connecting step is a step for connecting the second division 4 to the first division 3, as shown in Fig. 6. The first division 3 and the second division 4 are connected by fastening the flange portion 35 in the straight pipe portion 34 of the first division 3 to the lower flange portion 43 of the upstream pipe portion 41 of the second division 4 with fasteners B such as bolts and nuts. By performing the first closing step, the upper end (downstream end) of the straight pipe portion 34 of the first division 3 is closed with the dual-purpose closing member 61, so that the connection work between the first division 3 and the second division 4 can be easily performed while preventing the fluid from leaking out to the outside.

[0082] In the connecting step, as shown in FIG. 6, after the first split body 3 and the second split body 4 are connected, a water pressure test device 102 is connected to the second split body 4 to perform a water pressure test. A first water pressure test cover 101 is attached to the upper end of the upstream pipe section 41 of the second split body 4, and a second water pressure test cover 105 is attached to the end of the downstream pipe section 42 of the second split body 4, and the second split body 4 is in a sealed state. A water pressure test connector 104 is connected to the first water pressure test cover 101, and test water can be supplied from the water pressure test device 102 to the inside of the second split body 4 through the water pressure test connector 104. In the water pressure test, the pressure inside the second split body 4 is measured by a pressure gauge 103 while test water is being supplied to the inside of the second split body 4 to check whether there is any fluid leakage.

[0083] If the hydraulic test confirms that there is no fluid leakage, then a valve device 7 such as a valve can be attached to the downstream pipe section 42 of the second division 4, as shown in Fig. 7. The valve device 7 is connected to the downstream pipe section 42 of the second division 4 in a hermetically sealed state by fastening a connecting flange section 45 in the downstream pipe section 42 of the second division 4 to a flange section of the valve device 7 with fasteners such as bolts and nuts.

[0084] (Second closure process) 10, this second blocking step is a step for blocking the second divided body 4 with a dual-purpose blocking member 61. An insertion machine 51 is attached to the upstream pipe portion 41 of the second divided body 4 for placing the second blocking member 61b (dual-purpose blocking member 61) at the second blocking position for blocking the upstream pipe portion 41 of the second divided body 4.

[0085] When attaching this insertion machine 51, first, an adapter 71 is connected to the combined blocking member 61 arranged at the first blocking position as shown in Fig. 7, and then, as shown in Fig. 8, the insertion shaft portion 53 of the insertion machine 51 is connected to the adapter 71. In this manner, in a state in which the insertion shaft portion 53 of the insertion machine 51 and the combined blocking member 61 are first connected via the adapter 71, the insertion machine main body 52, the support portion 54, the guide portion 55, etc. are assembled, and the insertion machine 51 is assembled to the upstream pipe portion 41 of the second divided body 4 as shown in Fig. 9.

[0086] In the second blocking process, as shown in FIG. 9, the dual-purpose blocking member 61 arranged at the first blocking position is moved to the second blocking position by the insertion machine 51 as shown in FIG. 10, thereby blocking the upper end (separate side opening end) of the upstream pipe section 41 in the second partition 4 with the dual-purpose blocking member 61.

[0087] Since the second blocking position shown in Fig. 10 is located above the first blocking position shown in Fig. 9, the insertion machine 51 moves the insertion shaft portion 53 connected to the dual blocking member 61 arranged at the first blocking position upward to move the dual blocking member 61 from the first blocking position to the second blocking position. At this time, as shown by the dotted line in Fig. 9, the communication passage 58 communicated with the inside of the insertion machine main body 52 in the insertion machine 51 is connected to the chip discharge plug 36 arranged in the first divided body 3. As a result, the upper space and the lower space of the dual blocking member 61 are communicated with each other through the communication passage 58, and the upper space and the lower space of the dual blocking member 61 are in an equal pressure state. Therefore, since the insertion machine 51 can be used to move the dual-purpose blocking member 61 to the second blocking position in a constant pressure state, the dual-purpose blocking member 61 can be moved to the second blocking position in a stable posture, and the dual-purpose blocking member 61 can properly block the upstream pipe portion 41 of the second divided body 4, as shown in Fig. 10. When communication is established through the communication passage 58, air is bled.

[0088] When the insertion machine 51 moves the combination blocking member 61 from the first blocking position to the second blocking position, as shown in Figures 9 and 10, an adapter 71 is connected to the insertion shaft 53 of the insertion machine 51, and the insertion shaft 53 is connected to the combination blocking member 61 via the adapter 71. As a result, even if the insertion length to reach the first blocking position is insufficient with the insertion shaft 53 alone, by connecting the adapter 71, the combination blocking member 61 placed at the first blocking position can be appropriately moved.

[0089] As shown in FIG. 14, a first engagement portion 84 that engages with the engagement groove portion 64 in the outer peripheral portion 62 of the dual-purpose blocking member 61 is provided at the first blocking position, and as shown in FIG. 15, a second engagement portion 94 that engages with the engagement groove portion 64 in the outer peripheral portion 62 of the dual-purpose blocking member 61 is provided at the second blocking position. Therefore, when the dual-purpose blocking member 61 is moved from the first blocking position to the second blocking position, the first engagement portion 84 and the second engagement portion 94 may hinder the movement of the dual-purpose blocking member 61. Therefore, when the dual-purpose blocking member 61 is moved from the first blocking position to the second blocking position by the insertion machine 51, the first water stop plug 83 is removed, and the first engagement portion 84 is screwed into the disengagement position. Furthermore, the second water stop plug 93 is removed, and the second engagement portion 94 is screwed into the disengagement position (the position where the second engagement portion 94 retracts outward and is disengaged from the engagement groove portion 64). This allows the combination blocking member 61 to be moved smoothly from the first blocking position to the second blocking position without being hindered by the first engaging portion 84 and the second engaging portion 94.

[0090] 15, a second restricting portion 95 having a second abutment portion 96 is disposed at the second blocking position. As a result, when the insertion machine 51 moves the combination blocking member 61 upward from the first blocking position and the combination blocking member 61 reaches the second blocking position, the second abutment portion 96 of the second restricting portion 95 abuts against the combination blocking member 61, restricting further upward movement of the combination blocking member 61. Therefore, the combination blocking member 61 can be appropriately moved upward with respect to the second blocking position.

[0091] When the dual-purpose blocking member 61 is moved from the first blocking position to the second blocking position, as shown in Fig. 15, the second engagement portion 94 is screwed into the engaging position (where the second engagement portion 94 protrudes inward and engages with the engagement groove portion 64), and then the second water stop plug 93 is attached, so that the second engagement portion 94 engages with the engagement groove portion 64 on the dual-purpose blocking member 61 side. Thus, the dual-purpose blocking member 61 arranged at the second blocking position is held at the second blocking position by the engagement between the second engagement portion 94 and the engagement groove portion 64 and the abutment between the second abutment portion 96 of the second restricting portion 95 and the dual-purpose blocking member 61. The first water stop plug 83 is screwed into the communication hole of the first position holding member 82.

[0092] In this manner, when the combination blocking member 61 is held in the second blocking position, the insertion machine 51 is removed.

[0093] (Flange lid installation process) As described above, by sequentially performing the drilling step, the first closing step, the connecting step, and the second closing step, the branch section 2 branching off from the fluid pipe 1 can be formed by the first division 3 and the second division 4. Finally, as shown in Fig. 11, a flange lid attachment step is performed in which the flange lid 6 is attached to the upper end of the upstream pipe section 41 of the second division 4.

[0094] 11 , the flange cover 6 is fixed to the upper end of the upstream pipe section 41 by fastening the upper flange section 44 and the flange cover 6 in the upstream pipe section 41 of the second division 4 with fasteners B such as bolts and nuts. At the joint between the first division 3 and the second division 4, a reinforcing metal fitting 8 is attached in a state in which it sandwiches the flange section 35 in the straight pipe section 34 on the first division 3 side and the lower flange section 43 in the upstream pipe section 41 on the second division 4 side.

[0095] [Another embodiment] Other embodiments of the present invention will be described below. Note that the configurations of the embodiments described below are not limited to being applied alone, but may also be applied in combination with the configurations of other embodiments.

[0096] (1) In the above embodiment, in the second closing step, the insertion machine 51 is directly attached to the upstream pipe portion 41 of the second division body 4 as shown in Fig. 9 and Fig. 10. Alternatively, for example, referring to Fig. 4, the operation valve 11 can be attached to the upstream pipe portion 41 of the second division body 4, and the insertion machine 51 can be attached to the operation valve 11.

[0097] In this case, in the second blocking step, the insertion machine 51 is assembled with the working valve 11 switched to the open state, and the dual-purpose blocking member 61 arranged at the first blocking position by the insertion machine 51 is moved to the second blocking position while the working valve 11 is kept in the open state. If the dual-purpose blocking member 61 cannot properly block due to some abnormality or the like, the working valve 11 can be switched from the open state to the closed state to prevent the fluid from leaking out, so the working valve 11 can be used as a backup in case some abnormality occurs.

[0098] (2) In the above embodiment, the dual-purpose blocking member 61 is provided to serve as both the first blocking member 61a and the second blocking member 61b, but the first blocking member 61a and the second blocking member 61b may be provided separately. In this case, in the second blocking step, the first blocking member 61a arranged at the first blocking position by the insertion machine 51 can be removed, and the second blocking member 61b can be inserted at the second blocking position by the insertion machine 51.

[0099] The second closing member 61b can also be used as the flange lid portion 6. For example, in the second closing step, the first closing member 61a arranged at the first closing position by the insertion machine 51 is removed, and the flange lid portion 6 is attached, so that the upstream pipe portion 41 of the second divided body 4 can be closed with the flange lid portion 6.

[0100] In this way, the blocking member is not limited to a dual-purpose blocking member 61 that serves as both the first blocking member 61a and the second blocking member 61b, but different configurations can be adopted for the first blocking member and the second blocking member, and various configurations can be adopted as appropriate.

[0101] (3) In the above embodiment, the valve device 7 such as a valve is illustrated as an example of a member connected to the downstream pipe portion 42 of the second division 4, but for example, a branched fluid pipe through which a branched fluid flows may be connected to the downstream pipe portion 42 of the second division 4. Therefore, the member connected to the downstream pipe portion 42 of the second division 4 is not limited to the valve device 7 such as a valve, and other members or devices may be used.

[0102] (4) In the above embodiment, the second division 4 has an upstream pipe section 41 and a downstream pipe section 42, with the upstream pipe section 41 provided as a connection section and the downstream pipe section 42 provided as a branch section forming section. Alternatively, for example, the second division 4 can have a second straight pipe section that is connectable to the straight pipe section 34 of the first division 3 and extends in the extension direction of the first division 3, and a valve device such as a gate valve that can open and close an intermediate section of the second straight pipe section, and the valve device can be installed in the intermediate section of the second straight pipe section so as to extend in a direction perpendicular to the extension direction of the straight pipe section 34 of the first division 3. In this case, the second straight pipe section can be provided as a connection section, and the valve device can be provided as a branch section forming section.

[0103] Furthermore, in addition to the valve device, various devices and members can be installed in the middle of the second straight pipe section so as to extend in a direction perpendicular to the extending direction of the straight pipe section 34 of the first division body 3. In this case, various devices and members can be provided as a branch portion forming portion.

[0104] (5) In the above embodiment, in the drilling process, the straight pipe portion 34 of the first divided body 3 is placed on the upper part of the outer periphery of the fluid pipe 1, and the drilling direction for drilling through holes in the fluid pipe 1 by the drilling machine 21 is set in a direction from the upper side to the lower side of the fluid pipe 1. However, for example, the straight pipe portion 34 of the first divided body 3 can be placed on a lateral side of the outer periphery of the fluid pipe 1, and the drilling direction for drilling through holes in the fluid pipe 1 by the drilling machine 21 can be a lateral direction along the horizontal direction from the lateral side to the fluid pipe 1, and the drilling direction can be changed as appropriate.

[0105] (6) In the above embodiment, the downstream pipe section 42 of the second partition 4 is provided so as to extend from an intermediate portion of the upstream pipe section 41 in a direction perpendicular to the extension direction of the straight pipe section 34 of the first partition 3. However, the extension direction of the downstream pipe section 42 may be, for example, a direction extending diagonally upward relative to the extension direction of the straight pipe section 34 of the first partition 3, and may be a direction intersecting the extension direction of the straight pipe section 34, rather than being limited to a direction perpendicular to the extension direction of the straight pipe section 34.

[0106] (7) In the above embodiment, when the combined blocking member 61 is held in the first blocking position, the first position holding portion 81 is configured as a screw type in which the first engagement portion 84 on the first divided body 3 side is screwed into the engagement position to engage the first engagement portion 84 with the engagement groove portion 64 on the combined blocking member 61 side, thereby holding the combined blocking member 61 in the first blocking position. Alternatively, for example, a plurality of first divided body side bayonet claws are arranged at intervals in the circumferential direction on the inner wall portion on the first divided body 3 side, a plurality of combined blocking member side bayonet claws are arranged at intervals in the circumferential direction on the outer wall portion on the combined blocking member 61 side, and the combined blocking member 61 is rotated to engage the first divided body side bayonet claws with the combined blocking member side bayonet claws, thereby holding the combined blocking member 61 in the first blocking position. Various other engagement methods can be adopted.

[0107] Further, like the first position retaining portion 81, the second position retaining portion 91 is not limited to the screw type, but may employ a bayonet type or any other type of engagement system. [Explanation of symbols]

[0108] 1 Fluid tube 2 Branch 3 1st division body 4 Second division body 21 Drilling machine 34 Straight pipe part 41 Upstream pipe section (connection section) 42 Downstream pipe section (branching section) 61 Dual-purpose blocking member 61a first closing member 61b second blocking member 81 1st position holding part 85 First Regulatory Department 91 Second position holding part 95 Second Regulatory Department L1 First setting length L2 Second setting length

Claims

1. A method for forming a branch portion in a fluid pipe, comprising: The branch portion includes a first divided body and a second divided body, the first divided body has a straight pipe portion that is freely connectable to an outer periphery of the fluid pipe and extends in a direction perpendicular to the axial direction of the fluid pipe, the second division body has a connection portion connectable to the first division body and a branch portion forming portion extending in a direction intersecting the extension direction of the first division body, and the length of the first division body in the extension direction is set to a second set length in a form that ensures a space for arranging the branch portion forming portion in the extension direction of the first division body, A length of a straight pipe portion in the first division body is set to a first set length that is shorter than a second set length of the second division body, a drilling step of disposing a straight pipe portion of a first division body on an outer periphery of the fluid pipe and drilling a through hole in the fluid pipe by a drilling machine through the straight pipe portion of the first division body; a first closing step of closing the first divided body with a first closing member; a connecting step of connecting the second divided body to the first divided body.

2. the second division body has an upstream pipe portion that is connectable to the straight pipe portion of the first division body and extends in the extension direction of the first division body, and a downstream pipe portion that extends from a middle portion of the upstream pipe portion in a direction intersecting the extension direction of the first division body, The upstream pipe section is provided as the connection section, and the downstream pipe section is provided as the branch section forming section, 2. The method for forming a branching portion of a fluid pipe according to claim 1, further comprising the steps of: after performing the connecting step, removing a first blocking member blocking the first division; and performing a second blocking step of blocking the separated side open end portion of the upstream pipe portion of the second division that is away from the fluid pipe with a second blocking member.

3. The fluid pipe is buried in the ground with the axial direction of the fluid pipe aligned horizontally, 3. The method for forming a branching portion of a fluid pipe according to claim 1 or 2, wherein in the drilling step, a straight pipe portion of the first divided body is placed on the upper part of the outer periphery of the fluid pipe, and a drilling direction for drilling a through hole in the fluid pipe by a drilling machine is set in a direction from the upper side to the lower side of the fluid pipe.

4. The first closing member is provided as a dual-purpose closing member that also serves as the second closing member, 3. The method for forming a branching portion of a fluid pipe as described in claim 2, wherein in the second blocking step, a dual-purpose blocking member serving as a first blocking member arranged at a first blocking position blocking the distal open end of the straight pipe section in the first division is moved to a second blocking position blocking the distal open end of the upstream pipe section in the second division, thereby blocking the distal open end of the upstream pipe section in the second division with the dual-purpose blocking member.

5. a first position retaining portion for retaining the dual-purpose blocking member at the first blocking position; 5. The method for forming a branched portion in a fluid pipe according to claim 4, wherein the second closing position is provided with a second position holding portion for holding the combination closing member in the second closing position.

6. the first position retaining portion is provided with a first restricting portion that allows movement of the dual-purpose blocking member on a side away from the fluid pipe and restricts movement of the dual-purpose blocking member on a side approaching the fluid pipe by contacting the dual-purpose blocking member, 6. The method for forming a branching portion of a fluid pipe as described in claim 5, wherein the second position maintaining portion is provided with a second regulating portion that allows movement of the dual-purpose closure member on the side approaching the fluid pipe and abuts against the dual-purpose closure member plug to regulate movement on the side away from the fluid pipe.

7. In a branching structure for a fluid pipe, a branch portion is formed in the fluid pipe, The branch portion includes a first divided body and a second divided body, the first divided body has a straight pipe portion that is freely connectable to an outer periphery of the fluid pipe and extends in a direction perpendicular to the axial direction of the fluid pipe, the second division has a connection portion connectable to the first division and a branch portion forming portion extending in a direction perpendicular to the extension direction of the first division, and the length of the first division in the extension direction is set to a second set length in a manner that a space for arranging the branch portion forming portion in the extension direction of the first division is secured; A branching portion forming structure for a fluid pipe, wherein a length of a straight pipe portion in the first division is set to a first set length that is shorter than a second set length of the second division.

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