Exist pipe branch device and exist pipe branch method

Abstract

To provide an exist pipe branch device and an exist pipe branch method capable of improving efficiency of construction work.SOLUTION: An existing pipe branching device 1 divides an existing pipe P1 through which fluid F flows, and branches the fluid F from the divided existing pipe P1. The existing pipe branching device 1 has: a trunk part that houses a portion to be cut, and has a first opening 11h formed at each end in a first direction in which the existing pipe P1 extends; a neck part 12 that communicates with the trunk part, and has a second opening 12h formed therein through which a cylindrical cutter is inserted to pierce the existing pipe P1 by rotating about a rotational axis RX extending along a second direction intersecting the first direction; and a branch pipe part 13 that has a third opening 13h formed therein to which a branch pipe P2 extending in a third direction intersecting the first and second directions is joined with the trunk part as a base end, where a second opening axis HX2 of the second opening 12h is offset with respect to at least one of a first opening axis HX1 of the first opening 11h and a third opening axis HX3 of the third opening 13h.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an existing pipe branching device and an existing pipe branching method. [Background technology]

[0002] Various techniques have been proposed for work on existing pipes such as water pipes (see, for example, Patent Document 1). Patent Document 1 discloses a method for installing a valve body by inserting the valve body into an existing fluid pipe, which allows the valve to be installed in an uninterrupted flow state. In the installation method disclosed in Patent Document 1, a cylindrical hole saw rotates around the axis of the existing fluid pipe to cut and divide the existing fluid pipe, and the valve body is installed in the divided portion of the existing fluid pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-3270 Summary of the Invention [Problem to be solved by the invention]

[0004] When dividing an existing fluid pipe (hereinafter referred to as "full cut") as in the valve body installation method disclosed in Patent Document 1, a hole saw used to divide the existing fluid pipe must be larger than the diameter of the existing fluid pipe. In other words, the larger the diameter of the existing fluid pipe to be worked on, the larger the hole saw must be. The larger the hole saw, the larger the equipment such as the drilling machine including the hole saw, and the larger the work space, which causes problems such as a decrease in the efficiency of the work.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide an existing pipe branching device and an existing pipe branching method that improve the efficiency of construction work. [Means for solving the problem]

[0006] A characteristic configuration of an existing pipe branching device according to the present invention is an existing pipe branching device that divides an existing pipe through which a fluid flows by perforating a portion of the existing pipe to be cut, and branches the fluid from the divided existing pipe, the device having a body portion that accommodates the portion to be cut and has a first opening formed at each end in a first direction in which the existing pipe extends, a neck portion that communicates with the body portion and has a second opening formed therein through which a cylindrical cutter is inserted to perforate the existing pipe by rotating about a rotation axis extending along a second direction intersecting the first direction, and a branch pipe portion that has the body portion as a base end and has a third opening formed therein to which a branch pipe extending in a third direction intersecting the first direction and the second direction is joined, and the second opening axis of the second opening is offset with respect to at least one of the first opening axis of the first opening and the third opening axis of the third opening.

[0007] According to this characteristic configuration, the second opening axis of the second opening, that is, the rotation axis (drilling center) of the cylindrical cutter inserted into the second opening coaxially with the second opening axis, is offset. Therefore, for example, even if a cylindrical cutter of the same diameter is used to drill a hole in the existing pipe as when the second opening axis is not offset from the first opening axis, it is possible to increase the opening area (flow path cross-sectional area) of the drilled portion (cut opening) of the existing pipe. In addition, by offsetting the rotation axis (drilling center) of the cylindrical cutter from the third opening axis, it is possible to ensure the required size as the flow path cross-sectional area of ​​the portion (third opening) where the existing pipe and the branch pipe communicate with each other, even if the diameter of the cylindrical cutter is reduced. This makes it possible to reduce the size of the cylindrical cutter that forms the cut opening that communicates with (opposes) the third opening. In addition, since it is possible to reduce the size of the cylindrical cutter, it is also possible to reduce the size of the existing pipe branching device. As a result, the equipment including the cylindrical cutter and the existing pipe branching device is reduced in size, the equipment is easier to handle, and the efficiency of the construction work is improved.

[0008] As another configuration, a center of a hole formed by the cylindrical cutter in the portion to be cut may be offset toward the third opening with respect to an axis of the first opening.

[0009] According to this characteristic configuration, the opening area of ​​the cutting opening formed by the large diameter portion of the cylindrical cutter of the same diameter can be made larger than that in the case where the offset is not provided, and as a result, the size of the equipment including the cylindrical cutter and the existing pipe branching device can be reduced.

[0010] As another configuration, the body portion may have a valve seat supporting a valve body that is inserted into the area to be cut and controls the flow of the fluid, and the valve seat may be bent in a V-shape when viewed along the second direction.

[0011] According to this characteristic configuration, it is possible to reduce the size of the existing pipe branching device (the opening area of ​​the second opening) compared to a configuration having a valve seat that is linear when viewed along the second direction, which makes it possible to avoid an increase in the size of the equipment (including construction equipment).

[0012] In another configuration, the valve seat may have a first seat portion extending in the third direction from a bend point of the V-shaped bend, and a second seat portion extending from the bend point toward a position between the downstream side of the bend point in the first direction and the branch pipe portion, and an auxiliary seat portion extending from the bend point toward a position between the upstream side of the bend point in the first direction and the branch pipe portion.

[0013] According to this characteristic configuration, the valve body can be inserted into the first housing in a stable posture compared to a configuration without an auxiliary seat portion. Therefore, the valve body does not tilt toward the upstream side in the first direction, and the insertion position of the valve body does not shift, so that the efficiency of the installation work can be improved.

[0014] As another configuration, the second seat portion and the auxiliary seat portion may be arranged symmetrically with respect to the third direction, and a first angle between the first seat portion and the second seat portion may be greater than a second angle between the second seat portion and the auxiliary seat portion.

[0015] Since the first seat extends in the third direction, the contact surface between the first seat and the valve body is formed along the third direction. Therefore, the force from the fluid flowing along the first direction can be absorbed by a surface perpendicular to the flow direction. On the other hand, since the second seat extends toward the area between the downstream side of the first direction and the branch pipe section, the contact surface between the second seat and the valve body is inclined with respect to the flow direction of the fluid, and the second seat and the valve body are easily separated by the fluid pressure. Therefore, according to this characteristic configuration, since the second angle between the second seat and the auxiliary seat is smaller than the first angle between the first seat and the second seat, the resistance to the fluid pressure can be improved at the contact surface between the valve body and the second seat or the auxiliary seat.

[0016] As another configuration, the body portion may have a guide supporting the valve body, and a height of the guide along the second direction may be greater than a height of the valve seat along the second direction.

[0017] According to this characteristic configuration, the movement of the valve disc in the first direction or the third direction is suppressed by the guide, so that the valve disc does not deviate from the insertion position. In addition, when the valve disc is inserted, the valve disc is guided by the guide, so that the workability of inserting the valve disc can be improved.

[0018] As another configuration, a center of a hole formed by the cylindrical cutter in the cutting target portion may be offset in the first direction with respect to the third opening axis.

[0019] According to this characteristic configuration, the opening area of ​​the cutting opening is sufficiently secured relative to the required opening area, making it possible to reduce the cutting width (the length of the cutting opening in the direction in which the existing pipe extends), thereby enabling the miniaturization of equipment including the cylindrical cutter and the existing pipe branching device.

[0020] As another configuration, the body portion may have a pair of opposing portions connected to the third opening and opposing each other in the first direction, and the pair of opposing portions may have different lengths in a direction along the first direction.

[0021] According to this characteristic configuration, the opening area of ​​the cutting opening is sufficiently secured relative to the required opening area, making it possible to reduce the cutting width (the length of the cutting opening in the direction in which the existing pipe extends), thereby enabling the miniaturization of equipment including the cylindrical cutter and the existing pipe branching device.

[0022] A feature of the existing pipe branching method of the present invention is that it is a method for dividing an existing pipe through which a fluid flows by drilling a portion of the existing pipe to be cut and branching the fluid from the divided existing pipe, the method including: an existing pipe branching device installation step of installing an existing pipe branching device having a branch pipe section to which a branch pipe through which the fluid flows branched from the existing pipe is joined, and accommodating a part of the existing pipe so as to include the portion to be cut; a drilling machine installation step of installing a drilling machine having a cylindrical cutter that rotates about a rotation axis extending along a second direction intersecting a first direction in which the existing pipe extends; and a drilling step of drilling the portion to be cut with the cylindrical cutter, wherein in the drilling step, the cylindrical cutter drills the portion to be cut by offsetting the drilling center of the cylindrical cutter with respect to at least one of the axis of the existing pipe and the axis of the branch pipe section.

[0023] According to this feature, it is possible to achieve the same effect as the above-mentioned existing pipe branching device.

[0024] As another feature, in the drilling step, the cylindrical cutter may drill a hole with the drilling center offset toward the branch pipe portion with respect to an axis of the existing pipe.

[0025] According to this feature, compared to a case where the offset is not provided, the opening area of ​​the cutting opening formed by the large diameter portion of the cylindrical cutter of the same diameter can be made larger, and as a result, the size of the equipment including the cylindrical cutter and the existing pipe branching device can be reduced.

[0026] As another feature, in the perforating step, the cylindrical cutter may perform perforation such that a perforation center is offset in a flow direction of the fluid with respect to an axis of the branch pipe portion.

[0027] According to this feature, the opening area of ​​the cutting opening is sufficiently secured relative to the required opening area, making it possible to reduce the cutting width (the length of the cutting opening in the direction in which the existing pipe extends), thereby enabling the miniaturization of equipment including the cylindrical cutter and the existing pipe branching device.

[0028] Another feature is that the method further includes a valve body insertion step of inserting a valve body that controls the flow of the fluid into the portion to be cut, and the existing pipe branching device has a plurality of drain ports for discharging or inflowing the fluid, and the valve body insertion step may be performed in a state where the drain port provided upstream of the existing pipe from the insertion position of the valve body is connected to the drain port provided downstream of the existing pipe from the insertion position.

[0029] When inserting a valve disc into a section of an existing pipe under uninterrupted flow conditions, fluid pressure acts on the upstream surface of the valve disc. In contrast, with this characteristic configuration, the existing pipe branching device has multiple drain ports for discharging or introducing fluid, and the valve disc insertion process is performed in a state where the drain port provided upstream of the valve disc insertion position is connected to the drain port provided downstream of the insertion position, so that the fluid pressure acting on the upstream surface of the valve disc can be reduced. This makes it possible to efficiently insert the valve disc, improving workability. [Brief description of the drawings]

[0030] [Figure 1] 1 is a diagram showing a configuration of a pipeline work device according to a first embodiment. [Diagram 2] 1 is a diagram showing a configuration of a pipeline work device according to a first embodiment. [Diagram 3] 3 is a view of the pipe line work device shown in FIG. 2 viewed along the axis of the existing pipe. [Figure 4] 1 is a diagram showing a configuration of a pipeline work device according to a first embodiment. [Diagram 5] FIG. 1 is an exploded perspective view showing a part of the configuration of a pipe work device according to a first embodiment. [Figure 6]2 is a view of the first housing according to the first embodiment, seen along the axis of the branch pipe. FIG. [Figure 7] 2 is a view of the first housing according to the first embodiment as viewed along the rotation axis. FIG. [Figure 8] 1 is a diagram showing the internal configuration of a pipe work device according to a first embodiment. [Figure 9] FIG. 2 is a flow diagram showing an existing pipe branching method according to the first embodiment. [Figure 10] FIG. 3 is a flow diagram showing an assembly process for the pipe work device according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing the internal configuration of a pipe work device according to a second embodiment. [Figure 12] 13 is a view of the first housing according to the third embodiment, seen along the rotation axis. FIG. [Figure 13] FIG. 11 is a perspective view of a valve base and a valve body according to a third embodiment. [Figure 14] FIG. 11 is a bottom view of the valve base according to embodiment 3. [Figure 15] 13 is a diagram showing the configuration of a valve body and a valve seat according to a third embodiment. FIG. [Figure 16] FIG. 11 is a diagram showing the configuration of a pipeline work device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] [Embodiment 1] Hereinafter, an existing pipe branching device and an existing pipe branching method according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a first housing 1 provided in a pipe line working device 100 will be described as an example of an existing pipe branching device. However, the present invention is not limited to the following embodiment, and various modifications are possible within the scope of the present invention.

[0032] [Outline of the Pipeline Work Device] The pipe work device 100 is attached to the existing pipe P1 when performing pipe work on the existing pipe P1 through which a fluid F flows. The pipe work includes branching work on the existing pipe P1, renewal work on the downstream side of the existing pipe P1, etc., and the pipe work device 100 is used for pipe work in an uninterrupted flow state where the flow of the fluid F is maintained.

[0033] In this embodiment, the fluid F flows from left to right when viewed in Fig. 1. The fluid F is, for example, water, and the existing pipe P1 is, for example, a water pipe buried in the ground along the horizontal direction.

[0034] The pipe work device 100 is a device for dividing an existing pipe P1 by drilling a hole in the middle part of the existing pipe P1 in a direction along the axis of the existing pipe P1 (hereinafter referred to as the "first pipe axis PX1"), and branching a fluid F from the divided point of the existing pipe P1.

[0035] Hereinafter, the horizontal direction in which the existing pipe P1 extends (the direction along the first pipe axis PX1) is referred to as the "X direction", the horizontal direction perpendicular to the X direction is referred to as the "Y direction", and the direction perpendicular to the X and Y directions (vertical direction) is referred to as the "Z direction". In addition, the upstream side in the X direction (flow direction) is referred to as the "upstream side X1", and the downstream side is referred to as the "downstream side X2". Furthermore, the vertical lower side in the Z direction is referred to as the "lower side Z1", and the vertical upper side is referred to as the "upper side Z2". The X direction is an example of the first direction, the Y direction is an example of the third direction, and the Z direction is an example of the second direction.

[0036] [Configuration of the Pipeline Work Device] The configuration of the pipe work apparatus 100 will be described with reference to Figures 1 to 3. Figure 1 is a diagram showing the configuration of the pipe work apparatus 100 when assembly is completed, and Figures 2 and 3 are diagrams showing the configuration of the pipe work apparatus 100 during drilling work.

[0037] The pipeline work device 100 includes a first housing 1 (an example of an existing pipe branching device), a work valve 2, a second housing 3, and a drilling machine 4.

[0038] [First cabinet] The first housing 1 accommodates a portion of the existing pipe P1 in the X direction. More specifically, the first housing 1 accommodates a section to be cut, which is a midway portion of the existing pipe P1, and a section adjacent to the section to be cut. In this embodiment, the first housing 1 is a divided housing divided vertically along the first pipe axis PX1, and is composed of a lower housing 1A on the lower side Z1 of the first pipe axis PX1 and an upper housing 1B on the upper side Z2 of the first pipe axis PX1. In this embodiment, the lower housing 1A and the upper housing 1B are joined by welding, with a plane (horizontal plane) along the X direction and the Y direction as the split surface.

[0039] The lower housing 1A and the upper housing 1B are joined together with a sealing member (not shown) interposed therebetween. This forms a sealed space around the existing pipe P1. A position fixing bolt (not shown) is screwed into each of the lower housing 1A and the upper housing 1B to center the lower housing 1A and the upper housing 1B with respect to the existing pipe P1. The tip of the position fixing bolt is screwed into each of the lower housing 1A and the upper housing 1B so as to abut against the existing pipe P1. Other details of the configuration of the first housing 1 will be described later.

[0040] [Work valve] The working valve 2 has a working valve case 20 and a working valve body 21. The working valve case 20 is disposed on the upper side Z2 of the first housing 1, and is joined to the first housing 1 by fastening members such as bolts. The working valve case 20 has a rectangular parallelepiped shape with the X direction as the longitudinal direction, and houses the working valve body 21 .

[0041] The working valve body 21 is a flat member, and is held in the working valve case 20 so as to be slidable along the X direction. The working valve body 21 changes its posture between a closed posture (see FIG. 1) and an open posture (see FIG. 2) by sliding inside the working valve case 20. When the working valve body 21 is in the closed posture shown in FIG. 1, an upper space on the upper side Z2 relative to the working valve body 21 and a lower space on the lower side Z1 relative to the working valve body 21 are blocked. On the other hand, when the working valve body 21 is in the open posture shown in FIG. 2, the upper space and the lower space are communicated.

[0042] [Second housing] The second housing 3 is disposed on the upper side Z2 of the working valve case 20, and is joined to the working valve case 20 by fastening members such as bolts. The second housing 3 has a circular tubular shape (cylindrical shape) when viewed along the Z direction. The second housing 3 includes a second housing space 30S that is circular when viewed along the Z direction. The second housing space 30S has a size that can accommodate a part of the drilling machine 4.

[0043] [Drilling machine] The drilling machine 4 has a drilling case 40, a hole saw 41, a center drill 42, and a rotating shaft 43. The hole saw 41 and the center drill 42 may be collectively referred to as a "cylindrical cutter." However, the cylindrical cutter may be composed of only the hole saw 41.

[0044] The drilled case 40 is disposed on the upper side Z2 of the second housing 3, and is joined to the second housing 3 by fastening members such as bolts.

[0045] The hole saw 41 has a cylindrical shape (circular when viewed in the Z direction) centered on the rotation axis RX of the rotation shaft 43.

[0046] The hole saw 41 rotates around the rotation axis RX. As a result, the existing pipe P1 is drilled at a portion to be cut, and the existing pipe P1 is divided (divided into two). More specifically, as shown in FIG. 2, the drilling machine 4 completely separates the existing pipe P1 so that the pipes are separated without any connected portion in the X direction. In this embodiment, the existing pipe P1 is drilled by the drilling machine 4 so as to be divided (drilled so as to be completely separated), so that such drilling by the drilling machine 4 may be referred to as a "full cut". In the following, the portion of the existing pipe P1 drilled by the drilling machine 4 is referred to as a "drilled portion PH" (see FIG. 4). The drilled portion PH is composed of an opening (cut opening) formed by drilling (cutting) by the drilling machine 4.

[0047] The center drill 42 is disposed on the rotation axis RX (the center portion of the hole saw 41). The center drill 42 is provided with a plurality of burrs (not shown) for pulling up a drilled section of the existing pipe P1 (a cut-off part of the existing pipe P1) along the axial direction (Z direction) of the rotation axis RX. The center drill 42 is connected to one end (one end) of the rotation shaft 43 together with the hole saw 41.

[0048] The rotating shaft 43 extends along the Z direction, and at least a portion of it is housed in the drilling case 40. In detail, the rotating shaft 43 has an end (one end) opposite to an end (the other end) connected to the hole saw 41 and the center drill 42, which is housed in the drilling case 40. When the drilling case 40 is placed on the second housing 3, the portion exposed from the lower side Z1 of the drilling case 40 (the hole saw 41, the center drill 42, and a portion of the rotating shaft 43) is housed in the second housing space 30S of the second housing 3. The drilling case 40 and the second housing 3 may be connected in advance before being placed in the working valve case 20, and may be placed in the working valve case 20 as a unit.

[0049] The other end of the rotating shaft 43 is connected to a driving source (not shown) such as a motor. Power is transmitted from the driving source to the rotating shaft 43, which rotates about a rotation axis RX. As a result, the hole saw 41 and the center drill 42 rotate about the rotation axis RX, and the portion of the existing pipe P1 to be cut is drilled.

[0050] When drilling of the existing pipe P1 is completed, the hole saw 41, center drill 42 and the drilled section are pulled up to set the working valve body 21 in a closed position. The drilling case 40 of the drilling machine 4 is released from the second housing 3, the hole saw 41 and center drill 42 are pulled up from the second housing 3, and the drilling machine 4 is removed. After the drilling machine 4 is removed, a gate valve device 5 further provided in the pipeline work apparatus 100 is installed as shown in Figures 4 and 5. Note that Figure 4 is a diagram showing the configuration of the pipeline work apparatus 100 during the gate valve device installation work, and Figure 5 is an exploded perspective view showing a part of the configuration of the pipeline work apparatus 100 shown in Figure 4.

[0051] [Gate valve device] As shown in FIG. 4, the gate valve device 5 has a gate valve case 50 , a valve base 51 , a valve body 52 , and a shaft member 53 .

[0052] The gate valve case 50 is disposed on the upper side Z2 of the second housing 3, and is joined to the second housing 3 by a fastening member. The gate valve case 50 can also serve as the drilling machine 4 (drilling case 40). In this case, the gate valve device 5 can omit the gate valve case 50.

[0053] The valve base 51 supports a valve body 52. ​​The valve body 52 controls the flow of the fluid F (in this embodiment, the valve body 52 is a blocking plate that blocks the flow of the fluid F). The valve base 51 and the valve body 52 are connected to one end (one end) of a shaft member 53.

[0054] 5, the valve base 51 has a first bending point that is bent in a V-shape when viewed along the Z direction. The valve body 52 has an arc shape when viewed along the Z direction. The valve body 52 is connected to a first end 511a and a second end 511b on the side farther from the first bending point of the valve base 51 (see FIG. 8). Note that, for example, a protrusion for guiding the flow of the fluid F may be formed on the outer circumferential surface of the valve body 52.

[0055] 4, the shaft member 53 extends along the rotation axis RX, and at least a portion of it is housed in the gate valve case 50. In detail, the shaft member 53 has an end (one end) connected to the valve base 51 and the valve body 52 and an end (the other end) opposite the end. The second housing space 30S of the second housing 3 has a size large enough to allow the insertion of the valve base 51 and the valve body 52. ​​When the gate valve case 50 is placed on the second housing 3, the valve base 51 and the valve body 52 exposed from the lower side Z1 of the gate valve case 50 are accommodated in the second housing space 30S of the second housing 3.

[0056] The other end of the shaft member 53 is connected to, for example, a crane (not shown) or the like. When the shaft member 53 is lowered by operating the crane or the like, the valve base 51 and the valve body 52 are sent into the perforated portion PH of the existing pipe P1 (see also FIG. 5).

[0057] [Lid] As shown in Fig. 5, the pipe work device 100 further includes a lid 6 that covers a second opening 12h of the neck 12 described below. The lid 6 is a circular flat plate when viewed along the Z direction, and is joined to the neck 12 by a fastening member or the like. The lid 6 is positioned so as to cover the second opening 12h of the neck 12 after the valve base 51 and the valve body 52 are fed into the perforated portion PH of the existing pipe P1 (see Fig. 8).

[0058] [Details of the first housing] Next, the configuration of the first housing 1 will be described in detail with reference to Fig. 5 to Fig. 8. Fig. 6 is a diagram (front view) showing the first housing 1 as viewed along the axis of the branch pipe P2, Fig. 7 is a diagram (top view) showing the first housing 1 as viewed along the rotation axis RX, and Fig. 8 is a diagram showing the internal configuration of the pipeline work apparatus 100 after gate valve device installation has been completed.

[0059] 5 to 8, the first housing 1 has a body 11, a neck 12, and a branch pipe 13. The body 11 and the branch pipe 13 are composed of the lower housing 1A and upper housing 1B described with reference to Figs. 1 and 2, and the neck 12 is composed of the upper housing 1B (see Fig. 3).

[0060] [Body] As shown in FIG. 6, the body 11 includes a working portion 111 and a pair of support portions 112.

[0061] The body 11 is arranged so that the working portion 111 accommodates the portion to be cut (portion to be drilled) of the existing pipe P1, and the pair of support portions 112 are arranged along the outer periphery of a portion of the existing pipe P1 adjacent to the portion to be cut.

[0062] A drilling operation for a portion to be cut is performed inside the working area 111. Hereinafter, the inside of the working area 111 is referred to as a "first housing space 111S."

[0063] As shown in FIG. 7, the working part 111 has a valve seat 16 that supports the valve base 51 and the valve body 52 described with reference to FIG. 4 and FIG. 5. In this embodiment, the valve seat 16 is bent in a V-shape when viewed along the Z direction. In detail, the valve seat 16 has a first seat 161 extending in the Y direction when viewed along the Z direction, and a second seat 162 inclined with respect to the first seat 161 and the first pipe axis PX1. The first seat 161 extends to the Y2 side with the second bending point as a base end, and the second seat 162 extends from the second bending point as a base end toward between the downstream side X2 and the branch pipe part 13 side (Y1 side). The valve seat 16 is arranged not only on the bottom wall part (wall on the lower side Z1) of the working part 111, but also on the side wall part (wall along the direction of the Z direction) extending from the bottom wall part to the upper side Z2. The valve seat 16 does not have to be V-shaped when viewed along the Z direction, but may be linear, as long as it is continuous from the side wall portion opposite the branch to the side wall portion beside the branch.

[0064] Each of the pair of support portions 112 extends in the X direction with the working portion 111 as a base end. Specifically, one support portion 112 extends to the upstream side X1, and the other support portion 112 extends to the downstream side X2.

[0065] A first opening 11h through which the existing pipe P1 is coaxially inserted is formed in the support portion 112. In other words, a first opening 11h is formed in each of both ends of the body portion 11 in the X direction.

[0066] 5, the first opening 11h has a circular shape when viewed along the X direction, and the axis of the first opening 11h extends along the X direction (see FIG. 3). Hereinafter, the axis of the first opening 11h will be referred to as the "first opening axis HX1."

[0067] [Neck] As shown in FIGS. 5 and 6, the neck portion 12 has a circular tubular (cylindrical) shape when viewed along the Z direction, and extends upward Z2 with the body portion 11 as a base end.

[0068] As shown in Fig. 7, the neck 12 is formed with a second opening 12h that communicates with the first housing space 111S of the body 11. A hole saw 41 and a center drill 42 are inserted into the second opening 12h when drilling the existing pipe P1. The second opening 12h is circular when viewed along the Z direction, and the axis of the second opening 12h extends along the Z direction. Hereinafter, the axis of the second opening 12h will be referred to as the "second opening axis HX2."

[0069] In this embodiment, the second opening axis HX2 is offset in the Y direction from the first opening axis HX1. More specifically, the second opening axis HX2 is offset from the first opening axis HX1 (first pipe axis PX1) toward the branch pipe section 13. Hereinafter, the amount by which the second opening axis HX2 is offset from the first opening axis HX1 (first pipe axis PX1) is referred to as a "first offset amount H1."

[0070] The first offset amount H1 is determined in advance based on the outer diameter of the branch pipe P2. The outer diameter of the branch pipe P2 is determined based on the outer diameter of the existing pipe P1 and / or the flow rate of the fluid F flowing through the existing pipe P1.

[0071] [Branch pipe section] As shown in FIGS. 5 to 8, the branch pipe portion 13 extends in the Y direction with the body portion 11 as a base end. Hereinafter, the side of the body 11 on which the branch pipe portion 13 is arranged will be referred to as the "Y1 side", and the opposite side will be referred to as the "Y2 side".

[0072] A third opening 13h to which the branch pipe P2 extending along the Y direction is joined is formed in the branch pipe portion 13. The third opening 13h communicates with the perforated portion PH described with reference to FIG. The third opening 13h has a circular shape when viewed along the Y direction (see FIG. 6), and the axis of the third opening 13h extends along the Y direction (see FIG. 7). Hereinafter, the axis of the third opening 13h will be referred to as the "third opening axis HX3." In this embodiment, the third opening axis HX3 is perpendicular (including substantially perpendicular; the same applies below) to each of the first opening axis HX1 and the second opening axis HX2.

[0073] [Existing pipe branching method] Next, an existing pipe branching method will be described with reference to Fig. 1 to Fig. 10. The existing pipe branching method is a method in which an existing pipe P1 through which a fluid F flows is divided by drilling a portion to be cut of the existing pipe P1, and the fluid F is branched from the divided existing pipe P1.

[0074] 9, the existing pipe branching method includes a pipeline work device assembly process S1, a drilling process S2, and a gate valve installation process S3 (an example of a valve body insertion process). In the drilling process S2, the above-mentioned drilling work is carried out, and in the gate valve installation process S3, the above-mentioned gate valve device installation work is carried out.

[0075] In the pipe work device assembly process S1, the pipe work device 100 is assembled to perform work on the section of the existing pipe P1 to be cut. Before assembling the pipe work device 100, preparatory work is carried out by a worker or the like. The preparatory work includes work to expose the existing pipe P1 above ground level, work to secure a work space, and the like.

[0076] 10, the pipeline work device assembly process S1 includes a first housing installation process S11 (an example of an existing pipe branching device installation process), a branch pipe installation process S12, a work valve installation process S13, a second housing installation process S14, and a drilling machine installation process S15. Note that the second housing installation process S14 and the drilling machine installation process S15 may be performed together (the second housing 3 and the drilling machine 4 may be connected in advance before being placed in the work valve case 20, and may be placed in the work valve case 20 as a unit).

[0077] In the first housing installation step S11, the first housing 1 is installed so as to house a part of the existing pipe P1, as shown in Fig. 1. More specifically, the first housing 1 is arranged so that the body 11 includes the portion of the existing pipe P1 to be cut. This completes the first housing installation step S11.

[0078] In the branch pipe installation step S12, the branch pipe P2 (see FIG. 8) is placed in the third opening 13h. The branch pipe P2 includes, for example, a branch pipe valve (not shown) configured to block the flow of the fluid F. The branch pipe P2 with the branch pipe valve closed is joined to the branch pipe section 13 (third opening 13h). This completes the branch pipe installation step S12.

[0079] In the working valve installation step S13, the working valve case 20 of the working valve 2 suspended by a crane (not shown) or the like is placed on the first housing 1 (neck 12) as shown in FIG. 1, and the working valve 2 is installed by joining it to the first housing 1 with fastening members or the like. This completes the working valve installation step S13. The working valve body 21 is set to a closed position except for the drilling step S2 and the gate valve installation step S3. Note that the valve box (case above the first housing 1 (neck 12)) and valve cover (case accommodating the working valve body 21 in an open state) of the working valve case 20 may be suspended separately by a crane and fastened together by bolts or the like, or the working valve case 20 assembled on-site may be suspended integrally by a crane.

[0080] In the second housing installation step S14, the second housing 3 suspended by a crane (not shown) or the like is placed on the upper side Z2 of the working valve 2 as shown in Fig. 1, and the second housing 3 is installed by joining it to the working valve 2 with fastening members or the like. This completes the second housing installation step S14.

[0081] In the drilling machine installation step S15, the drilling case 40 suspended by a crane (not shown) or the like is placed on the upper side Z2 of the second housing 3 and joined to the second housing 3 with fastening members, thereby installing the drilling machine 4. More specifically, in the drilling machine installation step S15, as shown in Fig. 3, the drilling machine 4 is placed so that the rotation axis RX of the hole saw 41 (center drill 42 and rotation shaft 43) of the drilling machine 4 coincides with the second opening axis HX2.

[0082] As described above, the second opening axis HX2 is offset toward the branch pipe section 13 (Y1 side) with respect to the first opening axis HX1 of the first opening 11h. That is, the drilling machine 4 is disposed so that the rotation axis RX is offset toward the branch pipe section 13 (Y1 side) with respect to the first opening axis HX1 (first pipe axis PX1). Note that the offset amount of the rotation axis RX with respect to the first opening axis HX1 (first pipe axis PX1) matches (including approximately matches; the same applies below) the first offset amount H1.

[0083] After the drilling machine 4 is arranged as described above, the drilling case 40 of the drilling machine 4 is joined to the second housing 3 by fastening members or the like. This completes the installation of the drilling machine 4, and the drilling machine installation step S15.

[0084] When the installation of the first housing 1, the work valve 2, the second housing 3, and the drilling machine 4 is completed and the branch pipe P2 is joined, the assembly of the pipeline work device 100 is completed and the pipeline work device assembly process S1 is completed.

[0085] In the drilling step S2 shown in Fig. 9, after the working valve body 21 of the working valve 2 is set to an open position as shown in Fig. 2, the hole saw 41 and the center drill 42 are lowered to the first housing space 111S. With the tip of the center drill 42 in contact with the portion of the existing pipe P1 to be cut, a drive source (not shown) connected to the other end of the rotating shaft 43 is driven. As a result, the rotating shaft 43, the hole saw 41, and the center drill 42 rotate about the rotation axis RX, and the hole saw 41 and the center drill 42 drill the portion of the existing pipe P1 to be cut.

[0086] As described above, the drilling machine 4 is arranged so that the rotation axis RX (center drill 42) is offset toward the branch pipe section 13 side (Y1 side) with respect to the first opening axis HX1 (first pipe axis PX1) (see FIG. 3). For this reason, the hole saw 41 drills holes by offsetting the rotation axis RX toward the branch pipe section 13 side (Y1 side; third opening 13h side) with respect to the first opening axis HX1 (first pipe axis PX1). As a result, the drilling center O of the drilled portion PH of the existing pipe P1 is offset toward the third opening 13h side with respect to the first pipe axis PX1 (first opening axis HX1). The drilling center O is the center (geometric center) of the drilled portion PH. In addition, the offset amount of the drilling center O with respect to the first pipe axis PX1 (first opening axis HX1) also coincides with the first offset amount H1.

[0087] As described above, when the existing pipe P1 is drilled and completely divided (fully cut) into the upstream side X1 and the downstream side X2, the hole saw 41, the center drill 42, and the section that is a part of the drilled existing pipe P1 are pulled up to the second housing space 30S of the second housing 3, and then the working valve body 21 is set to the closed position. Then, the working valve body 21 is lifted up to the second housing space 30S of the second housing 3 by a crane (not shown) or the like. Then, as shown in FIG. 1, after the working valve body 21 is set to the closed position, the section is taken out of the second housing 3, and the drilling machine 4 is removed, completing the drilling process S2.

[0088] In the gate valve installation process S3, the gate valve case 50 of the gate valve device 5, which is suspended by a crane (not shown) or the like, is placed on the upper side Z2 of the second housing 3, as shown in FIG. 4, and the gate valve device 5 is installed by joining it to the second housing 3 with fastening members.

[0089] After the working valve body 21 of the working valve 2 is set to the open position, the valve base 51 and the valve body 52 are fed into the portion PH to be pierced of the existing pipe P1 via the shaft member 53. More specifically, as shown in Fig. 8, the valve base 51 and the valve body 52 are placed in the portion PH to be pierced.

[0090] Once the valve base 51 and the valve body 52 are placed in the perforated portion PH, the connection between the valve base 51 and the valve body 52 and the shaft member 53 is released, and the second housing 3 and the components installed on the upper side Z2 of the second housing 3 (the shaft member 53, the gate valve case 50 that houses the shaft member 53, etc.) are removed, completing the gate valve installation process S3.

[0091] When the gate valve installation step S3 is completed, the lid 6 (see FIG. 5) is placed on the neck 12 so as to cover the second opening 12h, and is joined to the neck 12 with a fastening member or the like. Then, the branch pipe valve of the existing pipe P1 is opened. As a result, the fluid F flows from the upstream existing pipe P1 to the branch pipe P2 through the third opening 13h. Note that the branch pipe valve of the branch pipe P2 may be opened before the lid 6 is joined.

[0092] This completes the existing pipe branching work (existing pipe branching method).

[0093] [Embodiment 2] Next, a pipe work device 100 according to a second embodiment will be described with reference to Fig. 11. In the second embodiment, the offset direction of the drilling center O differs from that of the first embodiment. Note that, in the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description of the same components as those in the first embodiment will be omitted.

[0094] [First cabinet] 11, in the first housing 1 according to this embodiment, the second opening axis HX2 of the second opening 12h is offset from the third opening axis HX3 of the third opening 13h, not from the first opening axis HX1 of the first opening 11h. More specifically, the second opening axis HX2 is offset in the X direction (more specifically, downstream side X2) from the third opening axis HX3. Hereinafter, the amount by which the second opening axis HX2 is offset from the third opening axis HX3 is referred to as the "second offset amount H2."

[0095] As described above, the second opening axis HX2 is offset toward the downstream side X2 with respect to the third opening axis HX3, so the configuration of the first housing 1 (working portion 111 of the body 11) according to this embodiment also differs from the configuration of embodiment 1. In particular, the lengths along the X direction of the connection portions between the branch pipe section 13 and each of the pair of support portions 112 in the first housing 1 are different. Hereinafter, the downstream side X2 of the connection portions between the branch pipe section 13 and each of the pair of support portions 112 in the working portion 111 will be referred to as the "first opposing portion 151," and the upstream side X1 will be referred to as the "second opposing portion 152."

[0096] 11, a first length L1 of the first opposing portion 151 is longer than a second length L2 of the second opposing portion 152. The first opposing portion 151 and the second opposing portion 152 may be collectively referred to as the "connecting portion 15." Because the first length L1 is longer than the second length L2, even if the diameter of the hole saw 41 (the opening area of ​​the third opening 13h) is reduced for the purpose of downsizing the equipment, etc., the valve seat 16 can be secured as a space for arranging the valve body 52 on the downstream side X2 of the connecting portion 15 (the first opposing portion 151 of the first housing 1).

[0097] In addition, since the second opening axis HX2 is offset to the downstream side X2 with respect to the third opening axis HX3, the hole saw 41 of the drilling machine 4, which is arranged so that the second opening axis HX2 and the rotation axis RX are coaxial, offsets the rotation axis RX (center drill 42) to the downstream side X2 with respect to the third opening axis HX3 to drill the existing pipe P1. In other words, the hole saw 41 offsets the drilling center O to the downstream side X2 with respect to the third opening axis HX3 to drill the existing pipe P1. The offset amount of the drilling center O with respect to the third opening axis HX3 is equal to the second offset amount H2.

[0098] When the drilling by the hole saw 41 and the center drill 42 is completed (when the drilling step S2 shown in FIG. 9 is completed), the gate valve installation step S3 and subsequent steps are carried out in the same manner as in the first embodiment.

[0099] In this embodiment, the shapes of the valve base 51 and the valve seat 16 of the working part 111 of the body 11 included in the gate valve device 5 are also different from those in embodiment 1. In detail, as shown in Fig. 11, the valve base 51 and the valve seat 16 are configured in a straight line without bending when viewed along the Z direction.

[0100] [Effects of the embodiment] As described above, according to the above embodiment, the second opening axis HX2, i.e., the rotation axis RX (hole center O) of the hole saw 41 inserted into the second opening 12h coaxially with the second opening axis HX2, is offset from the first opening axis HX1 or the third opening axis HX3. For this reason, for example, even when a hole is drilled with a hole saw 41 of the same diameter as when the second opening axis HX2 is not offset from the first opening axis HX1, it is possible to increase the opening area (flow path cross-sectional area) of the perforated portion PH (cut opening). In other words, even if the diameter of the hole saw 41 is reduced, the required opening area (flow path cross-sectional area) of the perforated portion PH (cut opening) can be ensured. In addition, by offsetting the rotation axis RX (second opening axis HX2) of the hole saw 41 with respect to the third opening axis HX3, it is possible to ensure the required size (same as the flow path cross-sectional area when not offset) as the flow path cross-sectional area of ​​the portion (third opening 13h) where the existing pipe P1 and the branch pipe P2 communicate with each other, even if the diameter of the hole saw 41 is reduced. This makes it possible to reduce the size of the hole saw 41 that forms the perforated portion PH (cut opening). In addition, since it is possible to reduce the size of the hole saw 41, it is also possible to reduce the size of the first housing 1. As a result, the equipment including the hole saw 41 and the first housing 1 is reduced in size, making it easier to handle the equipment and improving the efficiency of the construction work.

[0101] In addition, since the equipment can be made smaller, it is possible to avoid an increase in the construction space required for preparation work, and the cost of transporting the equipment can also be reduced.

[0102] [Embodiment 3] Next, a pipe line working device 100 according to a third embodiment will be described with reference to Figs. 12 to 15. As shown in Fig. 12, the first seat portion 161 of the valve seat 16 according to the third embodiment extends from the Y1 side toward the Y2 side from the second bending point (the second opening axis HX2, an example of the bending point). In addition, the auxiliary seat portion 163 extends from the second bending point (the second opening axis HX2) toward the upstream side X1 and the branch pipe portion 13 side (the Y1 side). That is, the valve seat 16 according to the third embodiment has, in addition to the first seat portion 161 and the second seat portion 162, the auxiliary seat portion 163 inclined with respect to the first seat portion 161 and the first pipe axis PX1. Since the valve seat 16 has the auxiliary seat portion 163, the valve base 51 does not incline or shift toward the upstream side X1 when the valve base 51 is brought into contact with the valve seat 16. This makes it possible to improve the workability of the insertion work of the valve base 51 and the valve body 52. Incidentally, the first seat portion 161 may extend from the second bending point (second opening axis HX2) toward the Y2 side; however, if it extends from the Y1 side toward the Y2 side further from the second bending point (second opening axis HX2) as in this embodiment, the contact area between the valve base 51 and the valve seat 16 can be increased, and the posture of the valve base 51 and the valve body 52 can be made more stable.

[0103] The second seat 162 and the auxiliary seat 163 are provided symmetrically with respect to the third opening axis HX3. That is, the angle between the third opening axis HX3 and the second seat 162 is equal to the angle between the third opening axis HX3 and the auxiliary seat 163. In addition, the first angle α, which is the angle between the first seat 161 and the second seat 162, is set to be larger than the second angle β, which is the angle between the second seat 162 and the auxiliary seat 163.

[0104] The working area 111 according to the third embodiment has a bottom guide 17 (one example of a guide) protruding from the bottom surface of the working area 111 in the Z direction, and a side guide 18 protruding from the inner peripheral surface of the bottom guide 17 toward the first housing space 111S. The bottom guide 17 is disposed in a position spaced a predetermined distance from the outer peripheral edge of the first seat portion 161 toward the upstream side X1 and downstream side X2 so as to be parallel to the first seat portion 161. The shape of the bottom guide 17 may be a rectangular column or a cylinder, and may have a dimension smaller than the dimension of the first seat portion 161 in the Y direction. As shown in FIG. 15, the height of the bottom guide 17 along the Z direction may be greater than the height of the first seat portion 161 along the Z direction. In addition, the surface of the bottom guide 17 facing the upstream side X1 surface and the downstream side X2 surface of the first seat portion 161 may be parallel to the Z direction, but may be inclined so as to approach the first seat portion 161 as it approaches the lower side Z1 side. This makes it easier to align the valve base 51 and the valve body 52 when they are inserted.

[0105] The side guides 18 are provided on the inner peripheral surface of the working area 111 at positions spaced apart from the outer peripheral edge of the first seat portion 161 by a predetermined distance toward the upstream side X1 and the downstream side X2, at positions spaced apart from the outer peripheral edge of the second seat portion 162 by a predetermined distance in a direction parallel to the extension direction of the second seat portion 162, and at positions spaced apart from the outer peripheral edge of the auxiliary seat portion 163 by a predetermined distance in a direction parallel to the extension direction of the auxiliary seat portion 163. The side guides 18 may be formed continuously on the inner peripheral surface of the working area 111 along the Z direction, or a plurality of side guides 18 may be formed on the same straight line parallel to the Z direction with a distance therebetween. The side guides 18 facilitate the alignment of the valve body 52. Furthermore, the surfaces of the side guides 18, 18 facing each other across the first seat portion 161, the second seat portion 162, or the auxiliary seat portion 163 may be inclined so as to move away from the first seat portion 161, the second seat portion 162, or the auxiliary seat portion 163 toward the upper side Z2. This makes it easier to align the valve base 51 and the valve body 52 when they are inserted.

[0106] FIG. 13 shows the valve base 51 and the valve body 52 according to the third embodiment. The valve base 51 according to the third embodiment is not bent in a V-shape when viewed along the Z direction, but has a flattened circular shape. As shown in FIGS. 14 and 15, a first base 511, a second base 512, and a third base 513 extend downward Z1 from the lower surface of the valve base 51. Each of the first base 511, the second base 512, and the third base 513 is formed to abut against the first seat 161, the second seat 162, or the auxiliary seat 163 of the valve seat 16 when the valve body 52 is inserted into the insertion position. Therefore, the first base 511 extends from the center point on the bottom surface of the valve base 51 toward the Y2 side when the valve body 52 is inserted into the insertion position. Of course, the first base 511 may extend from the Y1 side toward the Y2 side from the center point on the bottom surface of the valve base 51. Similarly, the second base 512 extends from the center point toward the downstream side X2 and the branch pipe section 13 side (Y1 side), and the third base 513 extends from the center point toward the upstream side X1 and the branch pipe section 13 side (Y1 side).

[0107] In the posture where the valve body 52 is inserted to the insertion position, the second base 512 and the third base 513 are provided symmetrically with respect to the third opening axis HX3. Therefore, the angle between the third opening axis HX3 and the second base 512 is equal to the angle between the third opening axis HX3 and the third base 513. Similarly to the positional relationship between the first seat 161, the second seat 162, and the auxiliary seat 163 of the valve seat 16, the first angle α1 which is the angle between the first base 511 and the second base 512 is set to be larger than the second angle β2 which is the angle between the second base 512 and the third base 513. This can improve the resistance to the pressure of the fluid F at the contact surface between the second base 512 and the second seat 162 and the contact surface between the third base 513 and the auxiliary seat 163.

[0108] As shown in FIG. 13, the frame 54 extends from the first end 511a, the second end 511b, and the third end 511c, which are the intersections of the outer periphery of the valve base 51 and the first base 511, the second base 512, or the third base 513, toward the upper side Z2. The frame 54 is integrally formed with the first base 511, the second base 512, and the third base 513, and its end is connected to an upper plate 57 having a surface facing the surface of the upper side Z2 of the valve base 51. The upper plate 57 has an outer diameter substantially the same as the inner diameter of the neck 12 of the first housing 1. The frame 54 extending from the first end 511a and the second end 511b may be connected to the valve body 52. ​​In addition, in the position in which the valve body 52 is inserted, the frame 54 extending from the third end 511c may be in contact with the inner periphery of the body 11. As a result, the frame portion 54 is not disposed so as to block the first opening 11h, and therefore the flow of the fluid F is not impeded.

[0109] As shown in FIG. 13 and FIG. 14, a seal member 56 is disposed on the surfaces of the lower side Z1 of the first base portion 511, the second base portion 512, and the third base portion 513, the outer peripheral surface of the frame portion 54, and the outer peripheral surface of the upper plate 57. The seal member 56 may be disposed in a form of being fitted into grooves provided on the surfaces of the first base portion 511, the second base portion 512, the third base portion 513, the frame portion 54, and the upper plate 57. As shown in FIG. 14, the seal member 56 disposed on the first base portion 511 and the seal member 56 disposed on the second base portion 512 are integrally formed seal members 56a, which are different from the seal member 56b disposed on the third base portion 513. However, the seal member 56a and the seal member 56b may be integrally formed, and these and the seal members 56 disposed on the side surfaces of the frame portion 54 and the upper plate 57 may all be integrally formed.

[0110] Since the seal member 56 has a predetermined thickness, when the valve disc 52 is inserted into the insertion position, the seal member 56 comes into contact with the valve seat 16, as shown in Fig. 15. Also, in the frame 54, the inner peripheral surface of the working portion 111 comes into contact with the seal member 56 provided on the frame 54. The seal member 56 is deformed by the weight of the valve base 51 and the valve disc 52, so that the gate valve device 5 is kept sealed.

[0111] Next, a process for inserting the valve base 51 and the valve body 52 according to the third embodiment will be described. As shown in Fig. 12, drain ports 19a and 19b for discharging or introducing the fluid F are provided on the bottom surface of the working portion 111 in the first housing 1. The drain port 19a is located on the upstream side X1 with respect to the insertion position of the valve body 52, and the drain port 19b is located on the downstream side X2 with respect to the insertion position of the valve body 52.

[0112] In the third embodiment, as shown in FIG. 16, the gate valve installation step S3 is performed in a state where the drain port 19a and the drain port 19b are in communication with each other through the piping 190. When the valve body 52 is inserted into the section of the existing pipe P1 under an uninterrupted flow condition, the pressure of the fluid F acts on the surface of the upstream side X1 of the valve body 52. ​​Therefore, by performing the gate valve installation step S3 in a state where the drain port 19a and the drain port 19b are in communication with each other, the fluid F is allowed to flow from the drain port 19a to the drain port 19b, and the fluid pressure acting on the surface of the upstream side X1 of the valve body 52 can be reduced. After that, the valve of the drain port 19a is closed. This allows the gate valve installation step S3 to be performed efficiently, thereby improving the workability of the gate valve installation step S3.

[0113] In this embodiment, an example has been described in which the second opening axis HX2 is offset from the first opening axis HX1, but the check valve device 5 having the valve base 51 of this embodiment may also be offset from the third opening axis HX3, and can also be used in an example in which the second opening axis HX2 is not offset from the first opening axis HX1 and / or the third opening axis HX3.

[0114] [Another embodiment] The present invention may be configured as follows other than the above-described embodiment (common numbers and symbols as in the embodiment are used to designate components having the same functions as in the embodiment).

[0115] (1) The matters described in the first and second embodiments can be combined as appropriate. In detail, the second opening axis HX2 (drilling center O) may be offset toward the branch pipe section 13 (third opening 13h) from the first opening axis HX1 (first pipe axis PX1), and may also be offset in the X direction (e.g., downstream side X2) from the third opening axis HX3.

[0116] (2) In the above embodiment, an example has been described in which the first direction (X direction), the second direction (Z direction), and the third direction (Y direction) are perpendicular to each other. However, the first direction, the second direction, and the third direction are not limited to being perpendicular to each other.

[0117] (3) In the above embodiment, the first housing 1 is composed of a lower housing 1A below the first pipe axis center PX1 at a side Z1 and an upper housing 1B above the first pipe axis center PX1 at a side Z2. However, the first housing 1 may be composed of an upstream housing X1 and a downstream housing X2 whose dividing surface is a plane perpendicular to the horizontal plane.

[0118] (4) In the above embodiment, the lower housing 1A and the upper housing 1B are not limited to being joined by welding, and may be joined by fastening members such as bolts and nuts.

[0119] (5) In embodiments 1 and 2, the valve body 52 is not limited to a shielding plate that blocks flow, but may be a gate valve, a butterfly valve, a ball valve, etc., in which case the flow direction of the fluid F can be switched from the upstream of the existing pipe P1 to the branch pipe P2 or the downstream of the existing pipe P1.

[0120] (6) In the third embodiment, the valve seat 16 has the auxiliary seat 163, but the auxiliary seat 163 may not be provided, and the valve base 51 may be bent in a V shape. In this case, a guide or the like for suppressing misalignment or inclination of the valve base 51 and the valve body 52 when inserted may be provided on the upstream side X1 of the first seat 161 and the second seat 162. The guide may extend from the top surface of the valve base 51 toward the upper side Z2, similar to the bottom guide 17. [Industrial Applicability]

[0121] INDUSTRIAL APPLICABILITY The present invention can be utilized in an existing pipe branching device and an existing pipe branching method. [Explanation of symbols]

[0122] 1: First housing (existing pipe branching device) 4:Drilling machine 11: Torso 11h: 1st opening 12: Neck 12h: 2nd opening 13: Branch pipe section 13h: 3rd opening 151: First opposing portion (a pair of opposing portions) 152: Second opposing portion (a pair of opposing portions) 41: Hole saw (cylindrical cutter) 16: Valve seat 17: Bottom guide (guide) 19a: Drain port 19b: Drain port 52: Valve body 161: 1st seat 162:Second seat 163: Auxiliary seat F:Fluid HX1: 1st opening axis HX2: 2nd opening axis (bending point) HX3: 3rd opening axis O: Center of drilling P1: Existing pipe P2: Branch pipe RX:Rotation axis center S11: First housing installation process (existing pipe branching device installation process) S15: Drilling machine installation process S2: Drilling process S3: Gate valve installation process (valve body insertion process) X1: Upstream X2: Downstream side α: 1st angle β :Second angle

Claims

1. An existing pipe branching device that divides an existing pipe by drilling a portion to be cut in the existing pipe through which a fluid flows, and branches the fluid from the divided existing pipe, A body portion that accommodates the portion to be cut and has a first opening formed at each of both ends in a first direction in which the existing pipe extends; a neck portion communicating with the body portion and having a second opening through which a cylindrical cutter is inserted to drill a hole in the existing pipe by rotating about a rotation axis extending along a second direction intersecting the first direction; a branch pipe portion having a third opening formed therein and connected to a branch pipe extending in a third direction intersecting the first direction and the second direction, An existing pipe branching device, wherein a second opening axis of the second opening is offset with respect to at least one of a first opening axis of the first opening and a third opening axis of the third opening.

2. The existing pipe branching device according to claim 1 , wherein a center of a hole formed by the cylindrical cutter in the portion to be cut is offset toward the third opening with respect to an axis of the first opening.

3. The existing pipe branching device according to claim 1 or 2, wherein the body portion has a valve seat supporting a valve body that is inserted into the area to be cut to control the flow of the fluid, and the valve seat is bent in a V shape when viewed along the second direction.

4. The valve seat includes a first seat portion extending in the third direction from a bending point of the V-shape; a second seat portion extending from the bending point toward a position between the branch pipe portion and a downstream side of the bending point in the first direction, The existing pipe branching device according to claim 3 , wherein an auxiliary seat portion extends from the bend point toward a position between the branch pipe portion and a side upstream of the bend point in the first direction.

5. The second seat portion and the auxiliary seat portion are provided symmetrically with respect to the third direction, The existing pipe branching device according to claim 4 , wherein a first angle between the first seat and the second seat is greater than a second angle between the second seat and the auxiliary seat.

6. The body portion has a guide that supports the valve body, The existing pipe branching device according to claim 3 , wherein a height of the guide in the second direction is greater than a height of the valve seat in the second direction.

7. The existing pipe branching device according to claim 1 , wherein a center of a hole formed by the cylindrical cutter in the portion to be cut is offset in the first direction from an axis of the third opening.

8. the body portion has a pair of opposing portions connected to the third opening and opposing each other in the first direction, The existing pipe branching device according to claim 7 , wherein the pair of opposing portions have different lengths in the first direction.

9. A method for branching an existing pipe, comprising the steps of: drilling a portion of an existing pipe through which a fluid flows, thereby dividing the existing pipe, and branching the fluid from the divided existing pipe, an existing pipe branching device installation process, which installs an existing pipe branching device having a branch pipe section to which a branch pipe through which the fluid flows, the branching pipe being branched from the existing pipe, and which accommodates a part of the existing pipe so as to include the portion to be cut; a drilling machine installation process for installing a drilling machine having a cylindrical cutter that rotates about a rotation axis extending along a second direction intersecting a first direction in which the existing pipe extends; A perforation process in which the cylindrical cutter perforates the portion to be cut, A method for branching an existing pipe, in which, in the drilling process, the cylindrical cutter drills the portion to be cut by offsetting the drilling center with respect to at least one of the axis of the existing pipe and the axis of the branch pipe section.

10. The method for branching an existing pipe according to claim 9, wherein in the boring step, the cylindrical cutter boring is performed with the boring center offset toward the branch pipe portion with respect to an axis of the existing pipe.

11. The method for branching an existing pipe according to claim 9 , wherein in the drilling step, the cylindrical cutter drills a hole with the drilling center offset in a flow direction of the fluid with respect to an axial center of the branch pipe section.

12. The method further includes a valve body insertion step of inserting a valve body for controlling the flow of the fluid into the portion to be cut, The existing pipe branching device has a plurality of drain ports for discharging or introducing the fluid, The existing pipe branching method according to any one of claims 9 to 11, wherein the valve body insertion process is performed in a state in which the drain port provided on the existing pipe upstream of the insertion position of the valve body is connected to the drain port provided on the existing pipe downstream of the insertion position.

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