Existing pipe branching device and existing pipe branching method

Abstract

To provide an existing pipe branching apparatus and an existing pipe branching method capable of enhancing efficiency of construction operations.SOLUTION: An existing pipe branching apparatus 1 divides an existing pipe P1 through which a fluid F flows and branches the fluid F from the divided existing pipe P1. The existing pipe branching apparatus 1 includes a body portion that accommodates a portion to be cut and has first openings 11h formed at respective both ends in a first direction in which the existing pipe P1 extends, a neck portion 12 that communicates with the body portion and has a second opening 12h through which a hole saw is inserted, the hole saw cutting the existing pipe P1 by rotating about a rotation axis RX extending along a second direction intersecting the first direction, and a branch pipe portion 13 that has a third opening 13h to which a branch pipe P2 extending in a third direction intersecting the first direction and the second direction is joined with the body portion as a base end, wherein 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 Art]]

[0002] Various technologies have been proposed for work on existing pipes such as water pipes (see, for example, Patent Document 1). Patent Document 1 discloses a valve body installation method for inserting a valve body into an existing fluid pipe, which can be installed in a non-stop flowing state. In the installation method disclosed in Patent Document 1, a cylindrical hole saw rotates about the axis of the existing fluid pipe to cut and split the existing fluid pipe, and the valve body is installed in the split portion of the existing fluid pipe. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Application Publication No. 2022-3270 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] When an existing fluid pipe is split (hereinafter referred to as "full cutting") as in the valve body installation method disclosed in Patent Document 1, a hole saw used for splitting the existing fluid pipe needs to be larger than the diameter of the existing fluid pipe. That is, as the diameter of the existing fluid pipe to be worked increases, a larger hole saw is also required. The increase in size of the hole saw leads to an increase in size of equipment such as a perforator including the hole saw, an increase in construction space, and the like, which poses a problem of reducing the efficiency of construction work.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is 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] The characteristic configuration of the existing pipe branching device according to the present invention is an existing pipe branching device that divides an existing pipe by perforating a location to be cut in an existing pipe through which a fluid flows, and branches the fluid from the divided existing pipe, comprising: a body portion that accommodates the location to be cut and has first openings formed at each of the two ends in the first direction in which the existing pipe extends; a neck portion that communicates with the body portion and has a second opening through which a cylindrical cutter that perforates the existing pipe by rotating about a rotation axis that extends along a second direction intersecting the first direction is inserted; and a branch pipe portion that has the body portion as its base end and has a third opening through which a branch pipe extending in a third direction intersecting the first and second directions is joined, wherein 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] This feature configuration offsets 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. Therefore, even when drilling with a cylindrical cutter of the same diameter as when the second opening axis is not offset relative to the first opening axis, it is possible to increase the opening area (flow channel cross-sectional area) of the drilled portion (cutting opening) of the existing pipe. Furthermore, by offsetting the rotation axis (drilling center) of the cylindrical cutter relative to the third opening axis, it is possible to secure the required size as the flow channel cross-sectional area of ​​the portion where the existing pipe and the branch pipe communicate (third opening) even when the diameter of the cylindrical cutter is reduced. This makes it possible to miniaturize the cylindrical cutter that forms the cutting opening communicating with (facing) the third opening. In addition, because the cylindrical cutter can be miniaturized, the existing pipe branching device can also be miniaturized. As a result, the equipment including the cylindrical cutter and the existing pipe branching device can be miniaturized, making the equipment easier to handle and improving the efficiency of construction work.

[0008] In another configuration, the center of the hole drilled by the cylindrical cutter at the cutting location may be offset to the third opening side with respect to the first opening axis.

[0009] This feature configuration allows for a larger opening area in the cutting opening formed by the larger diameter portion of the cylindrical cutter of the same diameter, compared to a configuration without offsetting. As a result, the equipment, including the cylindrical cutter and the existing pipe branching device, can be miniaturized.

[0010] In another configuration, the body portion may have a valve seat that supports a valve element inserted into the cutting location to control the flow of the fluid, and the valve seat may be bent in a V-shape when viewed along the second direction.

[0011] This distinctive configuration allows for a smaller existing pipe branching device (opening area of ​​the second opening) compared to a configuration with a linear valve seat when viewed along the second direction. As a result, it is possible to avoid increasing the size of the equipment (including construction equipment).

[0012] In other configurations, the valve seat may have a first seat portion extending in the third direction from the V-shaped bending point, and a second seat portion extending from the bending point toward the area between the downstream side of the bending point in the first direction and the branch pipe portion, and an auxiliary seat portion may extend from the bending point toward the area between the upstream side of the bending point in the first direction and the branch pipe portion.

[0013] This distinctive configuration allows the valve body to be inserted into the first housing in a more stable position compared to a configuration without an auxiliary seat. As a result, the valve body does not tilt towards the upstream side in the first direction, nor does the insertion position of the valve body shift, thus improving the efficiency of the installation work.

[0014] In other configurations, the second seat and the auxiliary seat are provided symmetrically with respect to the third direction, and the first angle between the first seat and the second seat may be greater than the second angle between the second seat and the auxiliary seat.

[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 received from the fluid flowing in the first direction can be absorbed by a surface perpendicular to the direction of flow. On the other hand, since the second seat extends toward 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 direction of fluid flow, and the second seat and the valve body are easily separated by fluid pressure. Thus, with this characteristic configuration, 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, so the resistance to fluid pressure can be improved at the contact surface between the valve body and the second seat or the auxiliary seat.

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

[0017] With this feature configuration, the movement of the valve body in the first or third direction is suppressed by the guide, so the valve body does not shift from its insertion position. In addition, the valve body is guided by the guide during insertion, which improves the work efficiency of the valve body insertion process.

[0018] In another configuration, the center of the hole drilled by the cylindrical cutter at the cutting location may be offset in the first direction with respect to the third opening axis.

[0019] This feature configuration ensures that the opening area of ​​the cutting opening is sufficient to meet 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), and thus enabling miniaturization of the equipment, including the cylindrical cutter and the existing pipe branching device.

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

[0021] According to this characteristic configuration, since the opening area of the cut opening is sufficiently secured relative to the required opening area, it becomes possible to reduce the cutting width (the length of the cut opening in the direction in which the existing pipe extends), and the size of equipment including the cylindrical cutter and the existing pipe branching device can be reduced.

[0022] The existing pipe branching method according to the present invention is an existing pipe branching method for dividing the existing pipe by perforating a portion to be cut of the existing pipe through which a fluid flows, and branching the fluid from the divided existing pipe, comprising: an existing pipe branching device installation step of installing an existing pipe branching device that has a branch pipe portion to which a branch pipe through which the fluid branched from the existing pipe flows is joined, and accommodates a part of the existing pipe so as to include the portion to be cut; a perforator installation step of installing a perforator 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 perforation step in which the cylindrical cutter perforates the portion to be cut, wherein in the perforation step, the cylindrical cutter performs perforation by offsetting a perforation center at which the portion to be cut is perforated with respect to at least one of the axial center of the existing pipe and the axial center of the branch pipe portion.

[0023] According to this characteristic, the same operational effects as those of the above-mentioned existing pipe branching device can be achieved.

[0024] As another characteristic, in the perforation step, the cylindrical cutter may perform perforation by offsetting the perforation center toward the branch pipe portion side with respect to the axial center of the existing pipe.

[0025] According to this characteristic, compared with a case where no offset is performed, the opening area of the cut opening formed by the large-diameter portion of the cylindrical cutter having the same diameter can be increased. As a result, the size of equipment including the cylindrical cutter and the existing pipe branching device can be reduced.

[0026] As another characteristic, in the perforation step, the cylindrical cutter may perform perforation by offsetting the perforation center in the flow direction of the fluid with respect to the axial center of the branch pipe portion.

[0027] According to this feature, since the opening area of the cut opening is sufficiently secured relative to the required opening area, it becomes possible to reduce the cutting width (the length of the cut opening in the direction in which the existing pipe extends), and the size of equipment including the cylindrical cutter and the existing pipe branching device can be reduced.

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

[0029] When inserting a valve element into a portion to be cut of an existing pipe under a live-flow condition, fluid pressure acts on the upstream face of the valve element. In contrast, according to this characteristic configuration, the existing pipe branching device has a plurality of drain ports for discharging or letting in the fluid, and the valve element inserting step is performed in a state where the drain port provided upstream of the insertion position of the valve element is communicated with the drain port provided downstream of the insertion position, so the fluid pressure applied to the upstream face of the valve element can be reduced. This makes it possible to efficiently perform the step of inserting the valve element, and improves workability.

[0030] The existing pipe branching device according to the present invention is characterized by a mechanism that divides an existing pipe by cutting the portion of the existing pipe through which a fluid flows, and branches the fluid from the divided portion of the existing pipe, comprising: a body portion that houses the portion to be cut and has first openings formed at each of the two ends in the first direction in which the existing pipe extends; a neck portion that communicates with the body portion and has a second opening formed through which a hole saw is inserted to cut the existing pipe by rotating about a rotation axis that extends along a second direction intersecting the first direction; and a base portion that has the body portion as its base end and the first and second directions The device comprises a branch pipe section having a third opening into which a branch pipe extending in a third direction intersecting the direction is joined, and a gate valve device inserted into the cutting location to control the flow of the fluid, wherein 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, the cutting center cut by the hole saw at the cutting location is offset toward the third opening with respect to the first opening axis, and the gate valve device has a shielding plate that is curved concavely with respect to the second opening axis.

[0031] This feature configuration allows for a larger opening area in the cutting hole formed by the larger diameter portion of the hole saw, compared to a configuration without offsetting. As a result, the equipment, including the hole saw and the existing pipe branching device, can be miniaturized. Furthermore, the flow of fluid can be controlled by the shielding plate inserted into the cutting area.

[0032] Another feature is that the gate valve device may further have a valve base that supports the shielding plate and is bent in a V-shape when viewed along the second direction.

[0033] This characteristic configuration allows for a smaller existing pipe branching device (opening area of ​​the second opening) compared to a configuration where the shielding plate has a straight portion extending along the third direction when viewed along the second direction. As a result, it is possible to avoid increasing the size of the equipment (including construction equipment).

[0034] The existing pipe branching device according to the present invention is characterized by a mechanism that divides an existing pipe by cutting a portion of the existing pipe through which a fluid flows, and branches the fluid from the divided existing pipe, comprising: a body portion that accommodates the portion to be cut and has first openings formed at each of the two ends in the first direction in which the existing pipe extends; a neck portion that communicates with the body portion and has a second opening through which a hole saw is inserted for cutting the existing pipe by rotating around a rotation axis that extends along a second direction intersecting the first direction; and a third opening formed with the body portion as the base end and into which a branch pipe extending in a third direction intersecting the first and second directions is joined. The device comprises a branch pipe section and a cylindrical gate valve device inserted into the cutting location to control the flow of the fluid, wherein 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, the cutting center of the cutting location cut by the hole saw is offset toward the third opening with respect to the first opening axis, and the gate valve device comprises an upper plate that closes the second opening, a shielding plate that is curved concavely with respect to the second opening axis, a frame section that forms a plurality of openings through which the fluid flows, and a valve base section that supports the upper plate, the shielding plate and the frame section.

[0035] This feature configuration allows for a larger opening area in the cutting hole formed by the larger diameter portion of the hole saw, compared to a configuration without offsetting. As a result, the equipment, including the hole saw and the existing pipe branching device, can be miniaturized. Furthermore, the flow of fluid can be controlled by the shielding plate inserted into the cutting area.

[0036] Another feature is that the gate valve device may have two openings through which the fluid flows.

[0037] With this feature configuration, for example, the flow of fluid can be controlled by positioning one of the two openings opposite one of the first openings and the other opening opposite the third opening.

[0038] Another feature is that the frame portion may have a sealing member that contacts the valve seat formed on the body portion.

[0039] This characteristic configuration allows for maintaining a sealed state between the body and the gate valve device.

[0040] Other features include the body having a drain port located upstream of the insertion position of the gate valve device on the existing pipe side, and a drain port located downstream of the insertion position on the existing pipe side.

[0041] This feature configuration allows for a reduction in the fluid pressure acting on the upstream surface of the gate valve device when the gate valve device is inserted into the cutting location with the upstream and downstream drain ports connected.

[0042] Another feature is that the body portion may have a guide for guiding the gate valve device to be inserted into the cutting location.

[0043] With this feature configuration, the movement of the gate valve device in the first or third direction is suppressed by the guide, so the gate valve device does not shift from its insertion position. In addition, when inserting the gate valve device, the valve body is guided by the guide, which improves the work efficiency of the gate valve device insertion process.

[0044] Another feature is that the cutting center may be offset in the first direction with respect to the third opening axis.

[0045] Another feature is that the body portion is connected to the third opening and has a pair of opposing portions that face each other in the first direction, and the pair of opposing portions may have different lengths in the direction along the first direction.

[0046] The existing pipe branching method according to the present invention is characterized by dividing an existing pipe by cutting a target portion of the existing pipe through which a fluid flows, and branching the fluid from the divided existing pipe, and comprises an existing pipe branching device installation step of installing an existing pipe branching device that has a branch pipe section to which the branch pipe through which the fluid that has been branched from the existing pipe is joined, and that accommodates a part of the existing pipe including the target portion to be cut; a hole saw installation step of installing a hole saw that rotates about a rotation axis extending along a second direction intersecting a first direction in which the existing pipe extends; a cutting step of the hole saw cutting the target portion to be cut, and the target portion to be cut The cutting process includes a gate valve device insertion step of inserting a cylindrical gate valve device for controlling the flow of the fluid, wherein in the cutting step, the hole saw cuts the target portion with the cutting center offset from at least one of the axis of the existing pipe and the axis of the branch pipe portion, the existing pipe branch device has a neck portion through which the hole saw is inserted and a second opening is formed, and the gate valve device has an upper plate that closes the second opening, a shielding plate that is curved concavely with respect to the second opening axis of the second opening, a frame portion that forms a plurality of openings through which the fluid flows, and a valve base portion that supports the upper plate, the shielding plate and the frame portion.

[0047] This feature allows for the same effects and advantages as the existing pipe branching device described above.

[0048] Another feature is that, in the cutting process, the hole saw may cut with the cutting center offset to the branch pipe side with respect to the axis of the existing pipe.

[0049] Another feature is that, in the cutting process, the hole saw may cut with the cutting center offset in the direction of fluid flow relative to the axis of the branched pipe.

[0050] Another feature is that the existing pipe branching device has a plurality of drain ports for discharging or inflowing the fluid, and the gate valve device insertion process may be performed with the drain port located upstream of the existing pipe from the insertion position of the gate valve device and the drain port located downstream of the existing pipe from the insertion position in communication. [Brief explanation of the drawing]

[0051] [Figure 1] This diagram shows the configuration of the pipeline work device according to Embodiment 1. [Figure 2] This diagram shows the configuration of the pipeline work device according to Embodiment 1. [Figure 3] Figure 2 shows the pipeline work device as viewed along the axis of the existing pipe. [Figure 4] This diagram shows the configuration of the pipeline work device according to Embodiment 1. [Figure 5] This is an exploded perspective view showing a part of the configuration of the pipeline work device according to Embodiment 1. [Figure 6] This is a view of the first housing according to Embodiment 1, along the axis of the branch pipe. [Figure 7] This is a view of the first housing according to Embodiment 1, along the axis of rotation. [Figure 8] This diagram shows the internal configuration of the pipeline work device according to Embodiment 1. [Figure 9] This is a flowchart showing the method for branching existing pipes according to Embodiment 1. [Figure 10] This is a flowchart showing the assembly process of the pipeline work device according to Embodiment 1. [Figure 11] This diagram shows the internal configuration of the pipeline work device according to Embodiment 2. [Figure 12] This is a view of the first housing according to Embodiment 3, along the axis of rotation. [Figure 13] This is a perspective view of the valve base and valve body according to Embodiment 3. [Figure 14] This is a view of the valve base according to Embodiment 3, seen from below. [Figure 15]This figure shows the configuration of the valve body and valve seat according to Embodiment 3. [Figure 16] This diagram shows the configuration of the pipeline work device according to Embodiment 3. [Modes for carrying out the invention]

[0052] [Embodiment 1] Hereinafter, an existing pipe branching device and an existing pipe branching method according to embodiments of the present invention will be described with reference to the drawings. In this embodiment, as an example of an existing pipe branching device, a first housing 1 provided in the pipeline work device 100 will be described. However, the invention is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the invention.

[0053] [Overview of pipeline work equipment] The pipeline work device 100 is attached to the existing pipe P1 when performing pipeline work on the existing pipe P1 through which fluid F flows. Pipeline work includes branching work on the existing pipe P1 and replacement work on the downstream side of the existing pipe P1, and the pipeline work device 100 is used for pipeline work in a continuous flow state where the flow of fluid F is maintained.

[0054] In this embodiment, the fluid F is assumed to flow from left to right when viewed in Figure 1. The fluid F is, for example, water, and the existing pipe P1 is, for example, a water pipe buried underground along the horizontal direction.

[0055] The pipeline work device 100 is a device that divides the existing pipe P1 by drilling a hole in the middle of the existing pipe P1 in the direction along the axis of the existing pipe P1 (hereinafter referred to as "first pipe axis PX1"), and branches the fluid F from the divided portion of the existing pipe P1.

[0056] Hereinafter, the direction in which the existing pipe P1 extends horizontally (the direction along the axis PX1 of the first pipe) will be referred to as the "X direction," the direction perpendicular to the X direction horizontally will be referred to as the "Y direction," and the direction perpendicular to both the X and Y directions (vertical direction) will be referred to as the "Z direction." Furthermore, the upstream side in the X direction (flow direction) will be referred to as "upstream X1," and the downstream side as "downstream X2." In addition, the lower vertical side in the Z direction will be referred to as "lower Z1," and the upper vertical side as "upper Z2." Note that 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.

[0057] [Configuration of pipeline work equipment] The configuration of the pipeline work device 100 will be explained with reference to Figures 1 to 3. Figure 1 shows the configuration of the pipeline work device 100 when assembly is complete, and Figures 2 and 3 show the configuration of the pipeline work device 100 during drilling work.

[0058] The pipeline work device 100 comprises 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.

[0059] [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 the portion of the existing pipe P1 that is to be cut and the portion adjacent to the portion to be cut. In this embodiment, the first housing 1 is a divided housing that is divided vertically along the axis of the first pipe PX1, and consists of a lower housing 1A below the axis of the first pipe PX1 Z1 and an upper housing 1B above the axis of the first pipe PX1 Z2. In this embodiment, the lower housing 1A and the upper housing 1B are joined by welding, with the planes (horizontal planes) along the X and Y directions serving as the cutting surfaces.

[0060] The lower housing 1A and the upper housing 1B are joined with a sealing member (not shown) interposed between them. This creates a sealed space around the existing pipe P1. Position fixing bolts (not shown) are screwed into each of the lower housing 1A and the upper housing 1B to center them relative to the existing pipe P1. The tips of the position fixing bolts are screwed into each of the lower housing 1A and the upper housing 1B so as to abut the existing pipe P1. Further details of the configuration of the first housing 1 will be described later.

[0061] [Operating valve] The work valve 2 comprises a work valve case 20 and a work valve body 21. The work valve case 20 is positioned 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 work valve case 20 has a rectangular parallelepiped shape with the X direction as its longitudinal direction and houses the work valve body 21.

[0062] The working valve body 21 is a flat plate-shaped member and is held in the working valve case 20 so as to be slidable along the X direction. By sliding within the working valve case 20, the working valve body 21 changes its position between a closed position (see Figure 1) and an open position (see Figure 2). When the working valve body 21 is in the closed position shown in Figure 1, the upper space Z2 above the working valve body 21 and the lower space Z1 below the working valve body 21 are blocked. On the other hand, when the working valve body 21 is in the open position shown in Figure 2, the upper space and the lower space are in communication.

[0063] [Second cabinet] The second housing 3 is positioned above the work valve case 20 on Z2 and is joined to the work valve case 20 by fastening members such as bolts. The second housing 3 has a circular cylindrical shape when viewed along the Z direction. The second housing 3 includes a circular second housing space 30S when viewed along the Z direction. The second housing space 30S is large enough to accommodate a part of the drilling machine 4.

[0064] [Drilling machine] The drilling machine 4 comprises 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 are sometimes collectively referred to as a "cylindrical cutter." However, the cylindrical cutter may consist only of the hole saw 41.

[0065] The perforation case 40 is positioned on the upper side Z2 of the second housing 3 and is joined to the second housing 3 by fastening members such as bolts.

[0066] The hole saw 41 has a cylindrical shape (circular when viewed in the Z direction) centered on the rotation axis RX of the rotating shaft 43.

[0067] The hole saw 41 rotates around the rotation axis RX. This causes a hole to be drilled in the existing pipe P1 at the point to be cut, and the existing pipe P1 is divided (divided into two). Specifically, as shown in Figure 2, the drilling machine 4 completely separates the existing pipe P1 so that there are no connecting parts in the X direction. In this embodiment, since the existing pipe P1 is drilled in such a way as to be divided by the drilling machine 4 (drilled in such a way as to be completely separated), such drilling by the drilling machine 4 is sometimes referred to as a "full cut". Hereafter, the portion of the existing pipe P1 drilled by the drilling machine 4 will be referred to as the "drilled portion PH" (see Figure 4). The drilled portion PH consists of an opening (cut opening) formed by drilling (cutting) by the drilling machine 4.

[0068] The center drill 42 is positioned on the rotation axis RX (the central part of the hole saw 41). The center drill 42 is provided with multiple burrs (not shown) along the axial direction (Z direction) of the rotation axis RX for pulling up the drilled section (a part of the cut-off existing pipe P1) of the existing pipe P1. The center drill 42 is connected to one end (one end) of the rotation axis 43 together with the hole saw 41.

[0069] The rotating shaft 43 extends along the Z direction, and at least a portion of it is housed in the drilling case 40. More specifically, the end of the rotating shaft 43 opposite to the end (one end) that connects to the hole saw 41 and the center drill 42 (the other end) is housed in the drilling case 40. When the drilling case 40 is placed on the second housing 3, the portion of the drilling case 40 that is exposed from the lower side Z1 (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 on the work valve case 20 and then placed together as a single unit on the work valve case 20.

[0070] The other end of the rotating shaft 43 is connected to a drive source (not shown), such as a motor. Power is transmitted from the drive source to the rotating shaft 43, causing it to rotate around the rotation axis RX. As a result, the hole saw 41 and the center drill 42 rotate around the rotation axis RX, drilling a hole in the existing pipe P1 at the point to be cut.

[0071] Once drilling into the existing pipe P1 is complete, the hole saw 41 and center drill 42 and the drilled section are pulled up, and the working valve body 21 is set to the 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, the gate valve device 5, which is further provided by the pipeline work device 100, is installed, as shown in Figures 4 and 5. Figure 4 is a diagram showing the configuration of the pipeline work device 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 device 100 shown in Figure 4.

[0072] [Gate valve device] As shown in Figure 4, the gate valve device 5 includes a gate valve case 50, a valve base 51, a valve body 52, and a shaft member 53.

[0073] The gate valve case 50 is positioned on the upper side Z2 of the second housing 3 and is joined to the second housing 3 by fastening members. 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.

[0074] The valve base 51 supports the valve body 52. ​​The valve body 52 controls the flow of fluid F (in this embodiment, it is a shielding plate that blocks the flow of fluid F). The valve base 51 and the valve body 52 are connected to one end (one end) of the shaft member 53.

[0075] As shown in Figure 5, the valve base 51 has a first bending point that bends 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 Figure 8). Furthermore, projections that guide the flow of fluid F may be formed on the outer circumferential surface of the valve body 52.

[0076] As shown in Figure 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. More specifically, the end of the shaft member 53 opposite to the end (one end) that connects to the valve base 51 and valve body 52 (the other end) is housed in the gate valve case 50. The second housing space 30S of the second housing 3 is large enough to accommodate the valve base 51 and valve body 52. ​​When the gate valve case 50 is placed on the second housing 3, the valve base 51 and valve body 52 exposed from the lower side Z1 of the gate valve case 50 are housed in the second housing space 30S of the second housing 3.

[0077] The other end of the shaft member 53 is connected to, for example, a crane (not shown). By operating the crane, the shaft member 53 is lowered, and the valve base 51 and valve body 52 are fed into the drilled portion PH of the existing pipe P1 (see also Figure 5).

[0078] [Lid] As shown in Figure 5, the pipeline work device 100 further includes a cover portion 6 that covers the second opening 12h of the neck portion 12, which will be described later. The cover portion 6 is a circular flat plate when viewed along the Z direction and is joined to the neck portion 12 by fastening members, etc. The cover portion 6 is positioned to cover the second opening 12h of the neck portion 12 after the valve base portion 51 and valve body 52 have been fed into the perforated portion PH of the existing pipe P1 (see Figure 8).

[0079] [Detailed configuration of the first enclosure] Next, the configuration of the first housing 1 will be described in detail with reference to Figures 5 to 8. Figure 6 is a front view of the first housing 1 as seen along the axis of the branch pipe P2, Figure 7 is a top view of the first housing 1 as seen along the rotation axis RX, and Figure 8 is a diagram showing the internal configuration of the pipeline work device 100 after the gate valve device has been installed.

[0080] As shown in Figures 5 to 8, the first housing 1 has a body portion 11, a neck portion 12, and a branch pipe portion 13. The body portion 11 and the branch pipe portion 13 are composed of the lower housing 1A and the upper housing 1B, as explained with reference to Figures 1 and 2, and the neck portion 12 is composed of the upper housing 1B (see Figure 3).

[0081] [Torso] As shown in Figure 6, the torso 11 includes a work area 111 and a pair of support areas 112.

[0082] The body portion 11 is configured such that the work area 111 accommodates the cutting area (drilling area) of the existing pipe P1, and the pair of support portions 112 are positioned along the outer circumference of the portion (part) adjacent to the cutting area of ​​the existing pipe P1.

[0083] Inside the work area 111, drilling operations are performed on the area to be cut. Hereinafter, the inside of the work area 111 will be referred to as the "first housing space 111S".

[0084] Furthermore, as shown in Figure 7, the working area 111 has a valve seat 16 that supports the valve base 51 and valve body 52, which were described with reference to Figures 4 and 5. In this embodiment, the valve seat 16 is bent in a V-shape when viewed along the Z direction. Specifically, the valve seat 16 has a first seat portion 161 that extends in the Y direction and a second seat portion 162 that is inclined with respect to the first seat portion 161 and the first pipe axis PX1 when viewed along the Z direction. The first seat portion 161 extends towards the Y2 side with the second bending point as its base end, and the second seat portion 162 extends towards the area between the downstream side X2 and the branch pipe portion 13 side (Y1 side) with the second bending point as its base end. The valve seat 16 is located not only on the bottom wall portion (lower Z1 wall) of the working area 111, but also on the side wall portion (wall in the direction along the Z direction) that extends from the bottom wall portion to the upper Z2. Furthermore, the valve seat 16 does not need to be V-shaped when viewed along the Z direction; it does need to be straight, and it just needs to be continuous from the side wall on the opposite side of the branch to the side wall next to the branch.

[0085] Each of the pair of support portions 112 extends in the X direction with the work portion 111 as its base. Specifically, one support portion 112 extends upstream X1, and the other support portion 112 extends downstream X2.

[0086] A first opening 11h is formed in the support portion 112 through which the existing pipe P1 is inserted coaxially. In other words, a first opening 11h is formed at each end of the body portion 11 in the X direction.

[0087] As shown in Figure 5, the first opening 11h is circular when viewed along the X direction, and the axis of the first opening 11h extends along the X direction (see Figure 3). Hereinafter, the axis of the first opening 11h will be referred to as the "first opening axis HX1".

[0088] [Neck] As shown in Figures 5 and 6, the neck portion 12 is circular and cylindrical when viewed along the Z direction, and extends upward Z2 with the body portion 11 as its base end.

[0089] As shown in Figure 7, a second opening 12h is formed in the neck portion 12, which communicates with the first housing space 111S of the body portion 11. A hole saw 41 and a center drill 42 are inserted through 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".

[0090] In this embodiment, the second opening axis HX2 is offset in the Y direction relative to the first opening axis HX1. More specifically, the second opening axis HX2 is offset toward the branch pipe section 13 side relative to the first opening axis HX1 (first pipe axis PX1). Hereinafter, the amount by which the second opening axis HX2 is offset relative to the first opening axis HX1 (first pipe axis PX1) will be referred to as the "first offset amount H1".

[0091] The first offset amount H1 is predetermined 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.

[0092] [Branch pipe section] As shown in Figures 5 to 8, the branch pipe section 13 extends in the Y direction with the body section 11 as its base end. Hereinafter, the side on which the branch pipe section 13 is located relative to the body section 11 will be referred to as the "Y1 side," and the opposite side will be referred to as the "Y2 side."

[0093] A third opening 13h is formed in the branch pipe section 13, to which a branch pipe P2 extending along the Y direction is joined. The third opening 13h communicates with the perforated section PH, which was described with reference to Figure 5. The third opening 13h is circular when viewed along the Y direction (see Figure 6), and the axis of the third opening 13h extends along the Y direction (see Figure 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 approximately perpendicular; the same applies hereinafter) to the first opening axis HX1 and the second opening axis HX2, respectively.

[0094] [Method for branching existing pipes] Next, the method for branching existing pipes will be explained with reference to Figures 1 to 10. The method for branching existing pipes involves drilling holes at the points to be cut in the existing pipe P1 through which the fluid F flows, thereby dividing the existing pipe P1, and branching the fluid F from the divided existing pipe P1.

[0095] As shown in Figure 9, the existing pipe branching method includes a pipeline work device assembly step S1, a drilling step S2, and a gate valve installation step S3 (an example of a valve body insertion step). In the drilling step S2, the drilling work described above is performed, and in the gate valve installation step S3, the gate valve device installation work described above is performed.

[0096] In the pipeline work device assembly process S1, the pipeline work device 100 is assembled to perform work on the section of the existing pipe P1 to be cut. Before the assembly of the pipeline work device 100, preparatory work is carried out by workers, etc. Preparatory work includes exposing the existing pipe P1 from the ground and securing the work space.

[0097] As shown in Figure 10, the pipeline work device assembly process S1 includes the first housing installation process S11 (an example of the existing pipe branching device installation process), the branch pipe installation process S12, the work valve installation process S13, the second housing installation process S14, and the 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 placed in the work valve case 20 as a single unit).

[0098] In the first housing installation step S11, as shown in Figure 1, the first housing 1 is installed so as to accommodate a portion of the existing pipe P1. Specifically, the first housing 1 is positioned so that the body portion 11 includes the portion of the existing pipe P1 to be cut. This completes the first housing installation step S11.

[0099] In the branch pipe installation process S12, the branch pipe P2 (see Figure 8) is placed in the third opening 13h. The branch pipe P2 is equipped with, for example, a branch pipe valve (not shown) configured to shut off the flow of 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 process S12.

[0100] In the work valve installation process S13, the work valve case 20 of the work valve 2, which is suspended by a crane (not shown), is placed on the first housing 1 (neck portion 12) as shown in Figure 1, and the work valve 2 is installed by joining it with fastening members, etc. This completes the work valve installation process S13. The work valve body 21 is set to the closed position except in the drilling process S2 and the gate valve installation process S3. Note that the valve body (the case on top of the first housing 1 (neck portion 12)) and the valve cover (the case that houses the work valve body 21 in the open state) of the work valve case 20 may be suspended separately by a crane and fastened together with bolts, etc., or the work valve case 20 assembled on site may be suspended as a single unit by a crane.

[0101] In the second housing installation process S14, the second housing 3, which has been suspended by a crane (not shown) or the like, is placed above the work valve 2 Z2 as shown in Figure 1, and the second housing 3 is installed by joining it to the work valve 2 with fastening members, etc. This completes the second housing installation process S14.

[0102] In the drilling machine installation process S15, the drilling case 40, suspended by a crane (not shown), is placed on the upper side Z2 of the second housing 3, and the drilling machine 4 is installed by joining it with fastening members. Specifically, in the drilling machine installation process S15, as shown in Figure 3, the drilling machine 4 is positioned so that the rotation axis RX of the hole saw 41 (center drill 42 and rotating shaft 43) of the drilling machine 4 coincides with the second opening axis HX2.

[0103] As described above, the second opening axis HX2 is offset toward the branch pipe section 13 side (Y1 side) relative to the first opening axis HX1 of the first opening 11h. In other words, the drilling machine 4 is positioned such that the rotation axis RX is offset toward the branch pipe section 13 side (Y1 side) relative to the first opening axis HX1 (first pipe axis PX1). The amount of offset of the rotation axis RX relative to the first opening axis HX1 (first pipe axis PX1) is equal to (approximately equal to; the same applies hereafter) the first offset amount H1.

[0104] After positioning the drilling machine 4 as described above, the drilling case 40 of the drilling machine 4 is joined to the second housing 3 by fastening members, etc. This completes the installation of the drilling machine 4, and the drilling machine installation process S15 is completed.

[0105] Once the installation of the first housing 1, the work valve 2, the second housing 3, and the drilling machine 4 is complete, and the branch pipe P2 is joined, the assembly of the pipeline work device 100 is complete, and the pipeline work device assembly process S1 is completed.

[0106] In the drilling process S2 shown in Figure 9, as shown in Figure 2, the working valve body 21 of the working valve 2 is set to the open position, and then the hole saw 41 and center drill 42 are lowered to the first housing space 111S. With the tip of the center drill 42 in contact with the cutting location of the existing pipe P1, the drive source (not shown) connected to the other end of the rotating shaft 43 is driven. As a result, the rotating shaft 43, hole saw 41 and center drill 42 rotate around the rotation axis RX, and the hole saw 41 and center drill 42 drill the cutting location of the existing pipe P1.

[0107] As described above, the drilling machine 4 is positioned so that the rotation axis RX (center drill 42) is offset toward the branch pipe section 13 side (Y1 side) relative to the first opening axis HX1 (first pipe axis PX1) (see Figure 3). Therefore, the hole saw 41 drills by offsetting the rotation axis RX toward the branch pipe section 13 side (Y1 side; third opening 13h side) relative to the first opening axis HX1 (first pipe axis PX1). As a result, the drilling center O of the drilled section PH of the existing pipe P1 is offset toward the third opening 13h side relative to the first pipe axis PX1 (first opening axis HX1). The drilling center O is the center (geometric center) of the drilled section PH. Also, the amount of offset of the drilling center O relative to the first pipe axis PX1 (first opening axis HX1) is the same as the first offset amount H1.

[0108] As described above, once the existing pipe P1 is drilled and completely divided into upstream X1 and downstream X2 (fully cut), the hole saw 41, center drill 42, and the section which is a part of the drilled existing pipe P1 are lifted up to the second housing space 30S of the second housing 3, and the work valve body 21 is set to the closed position. After that, it is lifted up to the second housing space 30S of the second housing 3 by a crane (not shown) or the like. After that, as shown in Figure 1, once the work valve body 21 is set to the closed position, the section is removed to the outside of the second housing 3, the drilling machine 4 is removed, and the drilling process S2 is completed.

[0109] 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 Figure 4, and the gate valve device 5 is installed by joining it with the second housing 3 using fastening members.

[0110] After the working valve body 21 of the working valve 2 is set to the open position, the valve base 51 and valve body 52 are fed to the drilled portion PH of the existing pipe P1 via the shaft member 53. Specifically, as shown in Figure 8, the valve base 51 and valve body 52 are positioned at the drilled portion PH.

[0111] When the valve base 51 and valve body 52 are positioned in the drilled portion PH, the connection between the valve base 51 and 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 (shaft member 53, gate valve case 50 housing the shaft member 53, etc.) are removed, completing the gate valve installation process S3.

[0112] Once the gate valve installation process S3 is complete, the cover portion 6 (see Figure 5) is positioned on the neck portion 12 so as to cover the second opening 12h, and is joined to the neck portion 12 by fastening members, etc. Subsequently, the branch pipe valve of the existing pipe P1 is opened. As a result, the fluid F flows from the upstream existing pipe P1 through the third opening 13h to the branch pipe P2. Note that the branch pipe valve of the branch pipe P2 may be opened before the joining of the cover portion 6.

[0113] This completes the existing pipe branching work (existing pipe branching method).

[0114] [Embodiment 2] Next, with reference to Figure 11, the pipeline work device 100 according to Embodiment 2 will be described. In Embodiment 2, the direction in which the drilling center O is offset is different from that of Embodiment 1. In the following description, components identical to those in Embodiment 1 will be denoted by the same reference numerals, and detailed descriptions of components identical to those in Embodiment 1 will be omitted.

[0115] [First cabinet] As shown in Figure 11, in the first housing 1 according to this embodiment, the second opening axis HX2 of the second opening 12h is offset not with respect to the first opening axis HX1 of the first opening 11h, but with respect to the third opening axis HX3 of the third opening 13h. More specifically, the second opening axis HX2 is offset in the X direction (more specifically, downstream X2) with respect to the third opening axis HX3. Hereinafter, the amount by which the second opening axis HX2 is offset with respect to the third opening axis HX3 will be referred to as the "second offset amount H2".

[0116] As described above, the second opening axis HX2 is offset downstream X2 with respect to the third opening axis HX3, so the configuration of the first housing 1 (working portion 111 of the body 11) in this embodiment also differs from the configuration of Embodiment 1. Specifically, the length along the X direction of the connection portion between the branch pipe portion 13 and each of the pair of support portions 112 in the first housing 1 is different. Hereinafter, the downstream X2 of the connection portion between the branch pipe portion 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 X1 will be referred to as the "second opposing portion 152".

[0117] Specifically, as shown in Figure 11, the first length L1 of the first opposing portion 151 is longer than the second length L2 of the second opposing portion 152. The first opposing portion 151 and the second opposing portion 152 are sometimes 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 miniaturizing the equipment, a valve seat 16 can be secured on the downstream side X2 of the connecting portion 15 (the first opposing portion 151 of the first housing 1) to serve as space for arranging the valve body 52.

[0118] Furthermore, since the second opening axis HX2 is offset downstream X2 relative to the third opening axis HX3, the hole saw 41 of the drilling machine 4, which is positioned so that the second opening axis HX2 and the rotation axis RX are coaxial, drills the existing pipe P1 by offsetting the rotation axis RX (center drill 42) downstream X2 relative to the third opening axis HX3. In other words, the hole saw 41 drills the existing pipe P1 by offsetting the drilling center O downstream X2 relative to the third opening axis HX3. Note that the amount of offset of the drilling center O relative to the third opening axis HX3 is the same as the second offset amount H2.

[0119] Once drilling by the hole saw 41 and center drill 42 is complete (when the drilling process S2 shown in Figure 9 is completed), the gate valve installation process S3 and subsequent processes are executed in the same manner as in Embodiment 1.

[0120] Furthermore, in this embodiment, the shape of the valve base 51 and the valve seat 16 of the working portion 111 of the body 11 of the gate valve device 5 also differs from that of Embodiment 1. Specifically, as shown in Figure 11, the valve base 51 and the valve seat 16 are configured in a straight line without bending when viewed along the Z direction.

[0121] [Effects of the Embodiment] As described above, according to the above embodiment, the second opening axis HX2, that is, the rotation axis RX (drilling center O) of the hole saw 41 inserted into the second opening 12h coaxially with the second opening axis HX2, is offset with respect to the first opening axis HX1 or the third opening axis HX3. For this reason, even when drilling with a hole saw 41 of the same diameter as when the second opening axis HX2 is not offset with respect to the first opening axis HX1, it is possible to increase the opening area (flow channel cross-sectional area) of the drilled portion PH (cutting opening). In other words, even if the diameter of the hole saw 41 is reduced, the required opening area (flow channel cross-sectional area) of the drilled portion PH (cutting opening) can be secured. Furthermore, by offsetting the rotation axis RX (second opening axis HX2) of the hole saw 41 with respect to the third opening axis HX3, even when the diameter of the hole saw 41 is reduced, it is possible to secure the required size (equivalent to the flow path cross-sectional area when not offset) for the portion where the existing pipe P1 and the branch pipe P2 connect (third opening 13h). This makes it possible to miniaturize the hole saw 41 that forms the drilled portion PH (cutting opening). In addition, since the hole saw 41 can be miniaturized, the first housing 1 can also be miniaturized. As a result, the equipment, including the hole saw 41 and the first housing 1, is miniaturized, making the equipment easier to handle and improving the efficiency of construction work.

[0122] Furthermore, because the equipment can be made smaller, it is possible to avoid the need for a large construction space during preparation work. In addition, the costs required for transporting the equipment can also be reduced.

[0123] [Embodiment 3] Next, the pipeline work device 100 according to Embodiment 3 will be described with reference to Figures 12 to 15. As shown in Figure 12, the first seat portion 161 of the valve seat 16 according to Embodiment 3 extends from the Y1 side toward the Y2 side beyond the second bending point (second opening axis HX2, an example of a bending point). In addition, the auxiliary seat portion 163 extends from the second bending point (second opening axis HX2) toward the upstream side X1 and the branch pipe portion 13 side (Y1 side). That is, in addition to the first seat portion 161 and the second seat portion 162, the valve seat 16 according to Embodiment 3 has the first seat portion 161 and the auxiliary seat portion 163 that is inclined with respect to the first pipe axis PX1. Because the valve seat 16 has the auxiliary seat portion 163, the valve base portion 51 does not tilt or shift toward the upstream side X1 when the valve base portion 51 is brought into contact with the valve seat 16. Therefore, it is possible to improve the workability of the insertion work of the valve base portion 51 and the valve body 52. The first seat portion 161 may extend from the second bending point (second opening axis HX2) toward the Y2 side, but as in this embodiment, if it extends from the Y1 side toward the Y2 side beyond the second bending point (second opening axis HX2), the contact area between the valve base portion 51 and the valve seat 16 can be increased, making it possible to stabilize the position of the valve base portion 51 and the valve body 52.

[0124] The second seat portion 162 and the auxiliary seat portion 163 are arranged symmetrically with respect to the third opening axis HX3. That is, the angle between the third opening axis HX3 and the second seat portion 162 is equal to the angle between the third opening axis HX3 and the auxiliary seat portion 163. Furthermore, the first angle α, which is the angle between the first seat portion 161 and the second seat portion 162, is set to be greater than the second angle β, which is the angle between the second seat portion 162 and the auxiliary seat portion 163.

[0125] The working area 111 according to Embodiment 3 has a bottom guide 17 (an example of a guide) that protrudes in the Z direction from the bottom surface of the working area 111, and a side guide 18 that protrudes toward the first housing space 111S from its inner circumferential surface. The bottom guide 17 is positioned parallel to the first seat 161 at a predetermined distance from the outer peripheral edge of the first seat 161 toward the upstream side X1 and the downstream side X2. The shape of the bottom guide 17 may be a rectangular prism or a cylinder, and it is preferable that it has dimensions smaller than the dimensions of the first seat 161 in the Y direction. As shown in Figure 15, it is preferable that the height of the bottom guide 17 along the Z direction be greater than the height of the first seat 161 along the Z direction. In addition, the surfaces of the bottom guide 17 facing the upstream side X1 and the downstream side X2 surfaces of the first seat 161 may be parallel to the Z direction, but may be inclined to approach the first seat 161 as they move toward the lower side Z1. This makes it easier to align the valve base 51 and the valve body 52 when inserting them.

[0126] The side guides 18 are provided on the inner circumferential surface of the work area 111 at positions separated by a predetermined distance from the outer circumferential edge of the first seat portion 161 toward the upstream side X1 and the downstream side X2, at positions separated by a predetermined distance from the outer circumferential edge of the second seat portion 162 in a direction parallel to the extending direction of the second seat portion 162, and at positions separated by a predetermined distance from the outer circumferential edge of the auxiliary seat portion 163 in a direction parallel to the extending direction of the auxiliary seat portion 163. The side guides 18 may be formed continuously on the inner circumferential surface of the work area 111 along the Z direction, or a plurality of side guides 18 may be formed spaced apart from each other on the same straight line parallel to the Z direction. 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 that they move away from the first seat portion 161, the second seat portion 162, or the auxiliary seat portion 163 as they move towards the upper Z2. This makes it easier to align the valve base portion 51 and the valve body 52 when inserting them.

[0127] Figure 13 shows the valve base 51 and valve body 52 according to Embodiment 3. The valve base 51 according to Embodiment 3 is not bent in a V-shape when viewed along the Z direction, but has a flattened circular shape. Also, as shown in Figures 14 and 15, a first base 511, a second base 512, and a third base 513 extend downward towards Z1 from the lower surface of the valve base 51. The first base 511, the second base 512, and the third base 513 are each formed to abut against the first seat portion 161, the second seat portion 162, or the auxiliary seat portion 163 of the valve seat 16 when the valve body 52 is inserted into the insertion position. Therefore, in the position where the valve body 52 is inserted into the insertion position, the first base 511 extends toward the Y2 side from the center point on the bottom surface of the valve base 51. Of course, the first base portion 511 may extend from the Y1 side toward the Y2 side beyond the center point on the bottom surface of the valve base portion 51. Similarly, the second base portion 512 extends from the center point toward the downstream side X2 and the branch pipe portion 13 side (Y1 side), and the third base portion 513 extends from the center point toward the upstream side X1 and the branch pipe portion 13 side (Y1 side).

[0128] In the position where the valve body 52 is inserted into the insertion position, the second base portion 512 and the third base portion 513 are arranged symmetrically with respect to the third opening axis HX3. Therefore, the angle between the third opening axis HX3 and the second base portion 512 is equal to the angle between the third opening axis HX3 and the third base portion 513. Also, similar to the positional relationship between the first seat portion 161, the second seat portion 162 and the auxiliary seat portion 163 of the valve seat 16, the first angle α1, which is the angle between the first base portion 511 and the second base portion 512, is set to be larger than the second angle β2, which is the angle between the second base portion 512 and the third base portion 513. This makes it possible to improve the resistance force against the pressure of the fluid F at the contact surfaces between the second base portion 512 and the second seat portion 162, and between the third base portion 513 and the auxiliary seat portion 163.

[0129] Furthermore, as shown in Figure 13, a frame portion 54 extends upward towards the upper Z2 from the first end portion 511a, the second end portion 511b, and the third end portion 511c, which are the intersections of the outer peripheral edge of the valve base portion 51 with the first base portion 511, the second base portion 512, or the third base portion 513. The frame portion 54 is integrally formed with the first base portion 511, the second base portion 512, and the third base portion 513, and its end is connected to an upper plate 57 having a surface facing the upper Z2 surface of the valve base portion 51. The upper plate 57 has an outer diameter that is approximately the same as the inner diameter of the neck portion 12 of the first housing 1. The frame portion 54 extending from the first end portion 511a and the second end portion 511b is preferably connected to the valve body 52. ​​In the position in which the valve body 52 is inserted, the frame portion 54 extending from the third end portion 511c is preferably in contact with the inner peripheral surface of the body portion 11. As a result, the frame portion 54 is not positioned to block the first opening 11h, and therefore does not obstruct the flow of the fluid F.

[0130] As shown in Figures 13 and 14, sealing members 56 are arranged on the lower Z1 surfaces of the first base portion 511, the second base portion 512, and the third base portion 513, the outer circumferential surface of the frame portion 54, and the outer circumferential surface of the top plate 57. The sealing members 56 may be arranged in a manner that allows them to fit 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 top plate 57. As shown in Figure 14, the sealing member 56 arranged on the first base portion 511 and the sealing member 56 arranged on the second base portion 512 are integrally formed sealing members 56a, and are different from the sealing member 56b arranged on the third base portion 513. However, the sealing members 56a and 56b may be integrally formed, and these and the sealing members 56 arranged on the sides of the frame portion 54 and the top plate 57 may all be integrally formed.

[0131] Since the sealing member 56 has a predetermined thickness, when the valve body 52 is inserted into the insertion position, the sealing member 56 and the valve seat 16 come into contact, as shown in Figure 15. Similarly, in the frame portion 54, the inner circumferential surface of the work area 111 and the sealing member 56 provided on the frame portion 54 come into contact. The sealing member 56 deforms due to the weight of the valve base 51 and the valve body 52, and the sealing member 56 maintains the sealed state of the gate valve device 5.

[0132] Next, the insertion process for the valve base 51 and valve body 52 according to Embodiment 3 will be described. As shown in Figure 12, drain ports 19a and 19b for discharging or inflowing fluid F are provided on the bottom surface of the working area 111 in the first housing 1. Drain port 19a is located upstream X1 of the insertion position of the valve body 52, and drain port 19b is located downstream X2 of the insertion position of the valve body 52.

[0133] In Embodiment 3, as shown in Figure 16, the gate valve installation process S3 is performed with drain ports 19a and 19b connected by piping 190. When inserting the valve body 52 into the cutting location of the existing pipe P1 under continuous flow conditions, the pressure of the fluid F acts on the upstream side X1 of the valve body 52. ​​Therefore, by performing the gate valve installation process S3 with drain ports 19a and 19b connected, the fluid F can be circulated from drain port 19a to drain port 19b, reducing the fluid pressure acting on the upstream side X1 of the valve body 52. ​​After that, the valve of drain port 19a is closed. This allows the gate valve installation process S3 to be performed efficiently, thereby improving the workability of the gate valve installation process S3.

[0134] In this embodiment, an example in which the second opening axis HX2 is offset with respect to the first opening axis HX1 has been described. However, the gate valve device 5 having the valve base 51 according to this embodiment may also have the second opening axis HX2 offset with respect to the third opening axis HX3, and can be used in examples where it is not offset with respect to the first opening axis HX1 and / or the third opening axis HX3.

[0135] [Another embodiment] The present invention may be configured as follows, in addition to the embodiments described above (parts having the same function as the embodiments are given the same numbers and reference numerals as the embodiments).

[0136] (1) The matters described in Embodiment 1 and Embodiment 2 can be combined as appropriate. Specifically, the second opening axis HX2 (drilling center O) may be offset toward the branch pipe section 13 (third opening 13h) with respect to the first opening axis HX1 (first pipe axis PX1), and also offset toward the third opening axis HX3 in the X direction (for example, downstream X2).

[0137] (2) In the above embodiment, the first direction (X direction), the second direction (Z direction), and the third direction (Y direction) were described as mutually orthogonal, but the first direction, the second direction, and the third direction are not limited to being mutually orthogonal.

[0138] (3) In the above embodiment, the first housing 1 is composed of a lower housing 1A located below Z1 from the first pipe axis PX1 and an upper housing 1B located above Z2 from the first pipe axis PX1. However, the first housing 1 may be composed of an upstream housing X1 and a downstream housing X2, with a plane perpendicular to the horizontal plane as the cutting surface.

[0139] (4) In the above embodiment, the lower housing 1A and the upper housing 1B are not limited to being joined by welding, but may also be joined by fastening members such as bolts and nuts.

[0140] (5) In embodiments 1 and 2, the valve body 52 is not limited to a shielding plate that blocks the flow, but may be a gate valve, butterfly valve, ball valve, etc. In this case, the direction of flow of the fluid F can be switched from upstream of the existing pipe P1 to the branch pipe P2 or downstream of the existing pipe P1.

[0141] (6) In Embodiment 3, the valve seat 16 is provided with an auxiliary seat portion 163, but the auxiliary seat portion 163 is not required, and the valve base 51 may be bent in a V-shape. In this case, a guide or the like may be provided upstream X1 of the first seat portion 161 and the second seat portion 162 to suppress displacement and tilting when inserting the valve base 51 and the valve body 52. ​​The guide may extend upward Z2 from the upper surface of the valve base 51, similar to the bottom guide 17. [Industrial applicability]

[0142] The present invention can be used in existing pipe branching devices and existing pipe branching methods. [Explanation of Symbols]

[0143] 1: First enclosure (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 part (a pair of opposing parts) 152: Second opposing part (a pair of opposing parts) 41: Hole saw (cylindrical cutter) 16: Alveolar 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 enclosure 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 side X2: Downstream side α: 1st angle β :Second angle

Claims

1. An existing pipe branching device that divides an existing pipe by cutting the target location of 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 having first openings formed at each of the two ends in the first direction in which the existing pipe extends, A neck portion is formed which a hole saw is inserted for cutting the existing pipe by rotating around a rotation axis that communicates with the body portion and extends along a second direction intersecting the first direction, A branch pipe section having the aforementioned body as its base end and a third opening formed therein where a branch pipe extending in a third direction intersecting the first and second directions is joined, The device includes a cylindrical gate valve device inserted into the cutting location to control the flow of the fluid, wherein 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. The cutting center of the cutting target area, cut by the hole saw, is offset to the third opening side with respect to the first opening axis. The gate valve device comprises an upper plate that closes the second opening, a shielding plate that is curved concavely with respect to the axis of the second opening, a frame portion that forms a plurality of openings through which the fluid flows, and a valve base portion that supports the upper plate, the shielding plate, and the frame portion. The frame portion is formed by three straight sections extending from the valve base towards the upper plate. The valve base has, in view along the axis of the second opening, linear first base, second base, and third base portions extending from and along the lower surface of the valve base, and one end of each of the first base, second base, and third base portions is distributed around the outer circumference of the valve base and connected to the frame portion, and the other end of each of the two base portions is connected at the position of the axis of the second opening, in an existing pipe branching device.

2. The gate valve device is an existing pipe branching device according to claim 1, having two openings through which the fluid flows.

3. The existing pipe branching device according to claim 1 or 2, wherein the frame portion has a sealing member that abuts against a valve seat formed on the body portion.

4. The existing pipe branching device according to claim 1, wherein the body portion has a drain port provided on the existing pipe side of the insertion position of the gate valve device and a drain port provided on the existing pipe side of the insertion position.

5. The existing pipe branching device according to claim 1, wherein the body portion has a guide for guiding the gate valve device to be inserted into the cutting location.

6. The existing pipe branching device according to claim 1, wherein the cutting center is offset in the first direction with respect to the third opening axis.

7. The body portion is connected to the third opening and has a pair of opposing portions that face each other in the first direction, The existing pipe branching device according to claim 6, wherein the pair of opposing portions have different lengths in the direction along the first direction.

8. A method for branching an existing pipe, which involves cutting the existing pipe at the point to be cut, thereby dividing the existing pipe, and branching the fluid from the divided existing pipe, An existing pipe branching device installation step involves installing an existing pipe branching device that has a branch pipe section to which a branch pipe through which the fluid that has branched off from the existing pipe is joined, and which accommodates a part of the existing pipe so as to include the part to be cut, A hole saw installation process involves installing a hole saw that rotates around a rotation axis extending along a second direction intersecting the first direction in which the existing pipe extends, The cutting process involves the hole saw cutting the target area, The process includes inserting a gate valve device into the cut-off location, which involves inserting a cylindrical gate valve device to control the flow of the fluid. In the cutting process, the hole saw cuts by offsetting the cutting center of the cutting point with respect to at least one of the axis of the existing pipe and the axis of the branch pipe section. The existing pipe branching device has a neck portion through which a second opening is formed, through which the hole saw is inserted. The gate valve device comprises an upper plate that closes the second opening, a shielding plate that is curved concavely with respect to the second opening axis of the second opening, a frame portion that forms a plurality of openings through which the fluid flows, and a valve base portion that supports the upper plate, the shielding plate, and the frame portion. The frame portion is formed by three straight sections extending from the valve base towards the upper plate. The valve base has, in view along the axis of the second opening, linear first base, second base, and third base portions extending from and along the lower surface of the valve base, and one end of each of the first base, second base, and third base portions is distributed around the outer circumference of the valve base and connected to the frame portion, and the other end of each of the two base portions is connected at the position of the axis of the second opening, in an existing pipe branching method.

9. The method for branching an existing pipe according to claim 8, wherein in the cutting step, the hole saw cuts by offsetting the cutting center toward the branch pipe portion with respect to the axis of the existing pipe.

10. The method for branching an existing pipe according to claim 8, wherein in the cutting step, the hole saw cuts with the cutting center offset in the direction of fluid flow relative to the axis of the branched pipe.

11. The aforementioned existing pipe branching device has a plurality of drain ports for discharging or inflowing the fluid, The method for branching an existing pipe according to any one of claims 8 to 10, wherein the gate valve device insertion step is performed with the drain port located upstream of the existing pipe from the insertion position of the gate valve device and the drain port located downstream of the existing pipe from the insertion position in communication.

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