Fluid tube perforation method

Abstract

To provide a fluid pipe drilling method which can eliminate a process.SOLUTION: In a fluid pipe drilling method, there are prepared an extension shaft 5 for bringing a gate valve 2 into an open state by connecting the gate valve 2 to an outer box 1 which is attached to a water pipe K, and connected with a cutter 4 for cutting the water pipe K, a slide pipe 6 inserted with the extension shaft 5, and an accommodation box 3 to which the slide pipe 6 is attached so as to be displaceable between the outside and the inside. The accommodation box 3 is connected to the outer box 1 via the gate valve 2 in a state that the slide pipe 6 which is inserted with the extension shaft 5 is extended inward, a shaft 70 of a drilling machine 7 is connected to the extension shaft 5 by attaching the drilling machine 7 to the outside of the accommodation body 3, the extension shaft 5 is protruded from the slide pipe 6 by making the shaft 70 of the drilling machine 7 advance, and the water pipe K is drilled by making the cutter 4 advance toward the water pipe K.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a fluid pipe drilling method for drilling a fluid pipe such as a water pipe. [Background technology]

[0002] In recent years, so-called non-stop water cutting has been practiced, in which water pipes are cut with a cutter while maintaining a continuous water supply without stopping the water supply upstream of existing water pipelines (see, for example, Patent Document 1). As shown in Patent Document 1, an extension shaft is used to compensate for the lack of stroke of the drilling machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6405231 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 uses a drilling device that includes an outer box attached to a fluid pipe, a storage box connected to the outer box via a gate valve, a slide pipe attached to the storage box and movable between the outside and inside of the storage box, an extension shaft inserted into the slide pipe, and a cutter connected to the extension shaft. The procedure is explained below. First, as shown in FIG. 1 of Patent Document 1, the slide pipe into which the extension shaft is inserted is fixed to the storage box in a contracted outward state, and the storage box is attached to the outer box with the cutter at the tip of the extension shaft housed in the storage box. The gate valve is opened, and the mechanism fixing the storage box and the slide pipe is released, displacing the slide pipe inward (toward the fluid pipe) of the storage box so that the slide pipe is extended inward. Next, a drilling machine is connected to the extension shaft, the mechanism fixing the extension shaft and slide pipe is released, and the extension shaft is advanced to drill the fluid pipe.

[0005] The drilling device in Patent Document 1 requires the manipulation of various members to proceed with the process, and therefore it is desired to reduce the process as much as possible.

[0006] The present disclosure provides a method for drilling a fluid pipe that can eliminate a step. [Means for solving the problem]

[0007] The fluid pipe drilling method disclosed herein involves connecting a gate valve to an outer box attached to a fluid pipe and opening the gate valve, preparing an extension shaft connected to a cutter for cutting the fluid pipe, a slide pipe into which the extension shaft is inserted, and a storage box in which the slide pipe is attached so that it can move between the outward and inward positions, connecting the storage box to the outer box via the gate valve while the slide pipe into which the extension shaft is inserted is extended inward, attaching a drilling machine to the outside of the storage box and connecting the shaft of the drilling machine to the extension shaft, advancing the shaft of the drilling machine so that the extension shaft protrudes from the slide pipe, and advancing the cutter toward the fluid pipe to drill the fluid pipe. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a side view showing an example of a drilling method according to the first embodiment of the present disclosure. [Figure 2] FIG. 2 is a longitudinal cross-sectional view showing an outer box to which a branch valve and a gate valve 2 are attached. [Figure 3] FIG. 2 is a side view showing the storage box 3, slide pipe 6, extension shaft 5 and cutter 4 in an assembled state. [Figure 4] FIG. 4 is a plan view corresponding to FIG. 3. [Figure 5] FIG. 10 is a vertical cross-sectional view showing how the suspended storage box is connected to the outer box via a gate valve. [Figure 6] FIG. 10 is a vertical cross-sectional view showing the state in which the storage box is connected to the outer box via a gate valve. [Figure 7] FIG. [Figure 8] FIG. 10 is a longitudinal cross-sectional view showing drilling a water pipe. [Figure 9]FIG. 10 is a longitudinal section view of the installation of the screw jack 9 after drilling. [Figure 10] FIG. 10 is a schematic cross-sectional view of the A2-A2 region in FIG. 9. [Figure 11] FIG. 10 is a vertical cross-sectional view showing a state in which the slide pipe is displaced outward from the storage box by the screw jack. [Figure 12] A vertical cross-sectional view showing the process of removing the cutter, slide pipe, extension shaft 5 and storage box 3 from the gate valve. [Figure 13] FIG. 10 is a longitudinal cross-sectional view showing a process of attaching an inner plug to an outer box. [Figure 14] FIG. 10 is a vertical cross-sectional view showing a process of attaching a lid to an outer box. [Figure 15] FIG. 10 is a longitudinal cross-sectional view showing a modified example of the inside plug. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] Hereinafter, a method for drilling a fluid pipe according to a first embodiment of the present disclosure will be described with reference to the drawings. In the first embodiment, a so-called top-cut method will be described as an example in which only the opening 12 side (upper side) of the outer casing 1 of the water pipe K (fluid pipe) is drilled, without drilling the opposite lower side, but the method is not limited to this. The top-cut method is a method in which a cylindrical cutter 4 having a diameter smaller than the diameter of the water pipe K (fluid pipe) is used to form a hole having a diameter smaller than the diameter of the water pipe K (fluid pipe).

[0010] In this construction method, as shown in Figure 7, a fluid pipe drilling device is used that includes an outer box 1 attached to a water pipe K, a storage box 3 connected to the outer box 1 via a check valve 2, a slide pipe 6 attached to the storage box 3 and movable between the outside and inside of the storage box 3, an extension shaft 5 inserted into the slide pipe 6, a cutter 4 that can be stored in the storage box 3 and connected to the extension shaft 5, and a drilling machine 7 that is attached to the outside of the storage box 3 with the slide pipe 6 inserted into the storage box 3 together with the extension shaft 5 and has a shaft 70 connected to the extension shaft 5.

[0011] As shown in FIGS. 1 and 2, an outer box 1 is attached to an existing water pipe K (an example of a fluid pipe). The water pipe K has not yet been drilled. FIG. 1 shows the state in which a branch valve 11 is attached to a branch pipe section 10 of the outer box 1 after the outer box 1 is attached to the water pipe K and a water pressure test is performed. FIG. 2 is a partial cross-sectional view showing the state in which a gate valve 2 is attached to an opening 12 of the outer box 1. The outer box 1 is made up of multiple divided sections and is configured so that it can be fitted to the outside of the existing water pipe K. These divided sections are connected with fasteners such as bolts and nuts, or integrated by welding. A storage box 3 can be connected to the outer box 1 via a gate valve 2. When the gate valve 2 is closed, an airtight space is formed inside the outer box 1 and inside the storage box 3. The outer box 1 has a branch pipe section 10, which is located above the water pipe K and below the gate valve 2. The opening of the outer box 1 is open in a direction (second axis direction AD2) perpendicular to the pipe axis direction AD1 of the water pipe K. The branch pipe section 10 is open in a third axis direction AD3 perpendicular to both the pipe axis direction AD1 and the second axis direction AD2 of the opening 12. In FIG. 1, a branch valve 11 is connected to the branch pipe section 10 and is in a closed state. Of course, a branch pipe (not shown) may be connected to the branch pipe section 10 and the branch valve 11 may be provided on the branch pipe.

[0012] FIG. 3 is a side view showing the housing box 3, slide pipe 6, extension shaft 5, and cutter 4 in an assembled state. FIG. 4 is a plan view corresponding to FIG. 3, as viewed from a line of sight parallel to the second axis direction AD2. As shown in FIGS. 3 and 4, the housing box 3 has a housing tube 30 and a housing lid 33 that closes the housing tube 30 and can hold the slide pipe 6. A flange 30a at a first end (lower end) of the housing tube 30 is fixed to the gate valve 2 side with fasteners 34 such as bolts and nuts (see FIG. 6). The flange 30a has a rectangular shape in a plan view (see FIG. 10), but is not limited thereto. A flange 30b (circular) at a second end (upper end) of the housing tube 30 is fixed to a first flange 33a of the housing lid 33 with fasteners 35.

[0013] The cutter 4 is capable of cutting the peripheral wall of the water pipe K. The cutter 4 is a cylindrical hole saw with a blade at its tip. A center drill 41 is provided at the center of the hole saw to penetrate and hold the cut piece of water pipe K. The extension shaft 5 is a member that compensates for the lack of stroke of the drilling machine 7, which will be described later, and the cutter 4 is connected to the tip of the extension shaft 5. The extension shaft 5 is inserted into the slide pipe 6 like a piston rod inserted into a cylinder. The drilling machine 7 of the first embodiment is configured so that the shaft 70 can slide within a predetermined range relative to the housing of the drilling machine 7. Therefore, the shaft 70 cannot slide beyond the predetermined range.

[0014] The slide pipe 6 is attached to the storage box 3 and configured to be displaceable between the outside and inside of the storage box 3. In FIG. 3, the slide pipe 6 is attached to the inside of the storage box 3 and is in a state where the slide pipe 6 is extended inward. As shown in FIG. 3, a bearing 31 that supports the slide pipe 6 is provided in the storage box 3. A sealant 32 that seals the gap between the storage box 3 and the slide pipe 6 is attached to the bearing 31. This allows the slide pipe 6 to slide along the second axial direction AD2 (the up-and-down direction in FIG. 3) while maintaining a sealed state relative to the storage box 3.

[0015] A bearing 61 that supports the extension shaft 5 is provided at the tip of the slide pipe 6. In FIG. 3, the extension shaft 5 is supported by the bearing 61 while inserted into the slide pipe 6. A sealant 62 that seals the gap between the extension shaft 5 and the slide pipe 6 is attached to the bearing 61. This allows the extension shaft 5 to slide along the second axial direction AD2 while maintaining a sealed state relative to the slide pipe 6.

[0016] The rear end of the slide pipe 6 is provided with a flange 63 having an opening in its center, a flange 64 positioned away from the flange 63 in the second axial direction AD2, and a rib 65 interposed between the flanges 63 and 64 to connect them. The flange 63 is fixed to a second flange 33b of the housing lid 33 with fasteners 36. As shown in FIG. 4, the flange 64 has a first bolt hole 64a for connecting to a drilling machine 7 (described later), a second bolt hole 64b for connecting a hanging piece 66 (see FIG. 5) for hanging the slide pipe 6, and a third bolt hole 64c for connecting a screw jack 9 (described later). These bolt holes 64a, 64b, and 64c are located at positions with different diameters from the axial center.

[0017] As shown in FIG. 5, the drilling method involves connecting the storage box 3 to the outer box 1 via the gate valve 2 with the slide pipe 6, into which the extension shaft 5 is inserted, extended inward. The gate valve 2 is in an open state. A hanging piece 66 is connected to the second bolt hole 64b of the flange 64 of the slide pipe 6, and the cutter 4, extension shaft 5, slide pipe 6, and storage box 3 are suspended together by a crane. While suspended by the crane, the slide pipe 6, into which the extension shaft 5 is inserted, is inserted into the outer box 1 with the slide pipe 6 extended inward. Next, as shown in FIG. 6, the storage box 3 is fastened to the gate valve 2 with fasteners 34 such as bolts. In the state shown in FIG. 6, the cutter 4 overlaps the branch pipe section 10 and the gate valve 2 in the vertical direction (second axial direction AD2).

[0018] Next, as shown in FIG. 7 , the drilling machine 7 is suspended and placed on the flange 64. The drilling machine 7 is then fastened to the first bolt hole 64a of the flange 64 with a fastener 73. The shaft 70 of the drilling machine 7 is connected to the extension shaft 5 with a fastener 72 such as a bolt. In this example, the flange 71 of the drilling machine 7 is connected to the flange 64 of the slide pipe 6, thereby attaching the drilling machine 7 to the storage box 3. As shown in FIGS. 3 , 5 , and 6 , the device of the first embodiment has a regulating member 8 that regulates movement of the extension shaft 5 in the second axial direction AD2 relative to the slide pipe 6. The regulating member 8 is detachably attached to the side surface of the rear end of the extension shaft 5 and protrudes outward so that the rear end of the extension shaft 5 can engage with the flange 63. The regulating member 8 is configured as a C-shaped split ring, but is not limited to this as long as it can regulate movement of the extension shaft 5.

[0019] As shown in Figure 7, after the shaft 70 of the drilling machine 7 is connected to the extension shaft 5, the restriction by the restricting member 8 is released. The restriction by the restricting member 8 is released by removing the restricting member 8 from the rear end of the extension shaft 5. By temporarily restricting the movement of the extension shaft 5 in this way, it is possible to prevent the extension shaft 5 from accidentally falling off the slide pipe 6, and it is possible to smoothly introduce the cutter 4 into the outer box 1.

[0020] A gap is formed between the flanges 63 and 64 so that an operator can insert his or her hand to perform work. Therefore, the work of attaching or detaching the restricting member 8 or the fastener 72 can be performed through the gap. In order to provide such a gap, the ribs 65 are provided intermittently around the axis, and are arranged at equal intervals in, for example, 4 to 8 locations around the axis.

[0021] Next, as shown in FIG. 8, the shaft 70 of the drilling machine 7 is advanced to insert the extension shaft 5 into the slide pipe 6 of the storage box 3, and the extension shaft 5 is protruded from the slide pipe 6 to advance the cutter 4 toward the water pipe K. The cutter 4 is lowered while rotating by a drive means (not shown) provided in the drilling machine 7, and cuts the peripheral wall of the water pipe K by moving within the outer box 1, thereby forming a perforation. During cutting, waste materials such as cutting powder are discharged by draining water through the drain valve 15 provided in the outer box 1. When cutting is completed, the shaft 70 of the drilling machine 7 is retracted to return the extension shaft 5 from the state protruding from the slide pipe 6 (see FIG. 8) to the state inserted into the slide pipe 6 (see FIG. 9), and the cutter 4 is raised to the position shown in FIG. 9. The cut piece P is hooked and collected by a piece locking portion 42 (a piece hook) that can protrude from the center drill 41 of the cutter 4. When the extension shaft 5 is returned to the inserted state in the slide pipe 6, a regulating member 8 is attached to the side of the rear end of the extension shaft 5 to prevent the extension shaft 5 from falling off, and the drilling machine 7 is removed.

[0022] Next, as shown in FIGS. 9 and 10 , a screw jack 9 is connected to the housing box 3 and the slide pipe 6. FIG. 10 is a schematic cross-sectional view of the A2-A2 portion of FIG. 9 . The screw jack 9, also known as a screw jack, is capable of adjusting the distance between the housing box 3 and the slide pipe 6. The screw jack 9 has a base 90, a screw shaft 91 extending from the base 90, an input shaft 92 for inputting rotational power, and an output end 93 whose distance from the base 90 changes depending on the input of rotational power to the input shaft 92. The screw jack 9 has a self-locking function. When the input of rotational power to the input shaft 92 is stopped, the screw jack 9 is internally locked, maintaining the distance between the housing box 3 and the slide pipe 6 (the distance between the base 90 and the output end 93). The base 90 of the screw jack 9 is fixed to the housing box 3, and the output end 93 of the screw jack 9 is fixed to the flange 64 of the slide pipe 6. In the first embodiment, the output end 93 is a nut provided on the rotating screw shaft 91, and moves up and down as the screw shaft 91 rotates, thereby varying the distance between the output end 93 and the base 90. Of course, the screw shaft 91 may extend and retract from the base 90 as it rotates, and the tip of the screw shaft 91 may serve as the output end 93.

[0023] As shown in FIG. 10, a plurality of screw jacks 9 are arranged, and an electric motor 94 (motor) is connected to the input shaft 92 of each screw jack 9. The drive of each electric motor 94 is controlled by a control unit 95. The fastener 67 that secures the housing box 3 and the slide pipe 6 is removed (see FIG. 9). Next, as shown in FIG. 11, while controlling the distance between the housing box 3 and the slide pipe 6 with the screw jack 9, the slide pipe 6 with the extension shaft 5 inserted (accommodating the extension shaft 5) is returned to the state displaced outward from the housing box 3. This makes it possible to prevent the slide pipe 6 from unexpectedly protruding even if the water pressure in the water pipe K is high. Furthermore, even if the water pressure in the water pipe K is low and the slide pipe 6 does not return, the screw jack 9 can appropriately displace the slide pipe 6 outward from the housing box 3. Next, the gate valve 2 is closed, and as shown in Figure 12, the cutter 4, slide pipe 6, extension shaft 5 and storage box 3 are lifted up by a crane while remaining together, and the storage box 3 is removed from the gate valve 2.

[0024] Next, as shown in Figure 13, an insertion machine 75 for holding the inner plug 13 is attached to the gate valve 2, and with the gate valve 2 in the open position, the inner plug 13 is inserted into the outer box 1. The inner plug 13 is used when the opening 12 of the outer box 1 has a large diameter. A large diameter opening 12 has a diameter of 600 mm or more. The inner plug 13 contacts the inner peripheral surface of the outer box 1. The inner plug 13 has a ring portion 13a that is sealed against the inner peripheral surface of the outer box 1 via a sealing material 13c, and a top portion 13b that covers the center of the ring portion 13a.

[0025] Once the insertion of the inner plug 13 is complete, the recess of the ring portion 13a is pressed with a fastener 13e from the outside of the outer box 1, and the inner plug 13 is fixed to the outer box 1. Next, the gate valve 2 and the insertion machine 75 are removed, and the lid 14 is attached to the outer box 1 as shown in Figure 14. The lid 14 closes the opening 12 of the outer box 1, and is fastened to a flange 16 that forms the opening 12 of the outer box 1 with a bolt and nut fastener 17.

[0026] <Modification> (1) In the first embodiment, the opening 12 of the outer box 1 has a large diameter, so the inner plug 13 is used, but the lid 14 may be used to close the box without using the inner plug 13.

[0027] (2) In the first embodiment, as shown in Fig. 13, the top 13b of the inside plug 13 is flat, but is not limited to this. For example, as shown in Fig. 15, the top 13b may have an arcuate portion 13d that protrudes inward from the outer box 1 in a cross section passing through the axis of the ring portion 13a. Because the arcuate portion 13d of the inside plug 13 protrudes inward from the outer box 1, the strength of the inside plug 13 is improved, and the inside plug 13 can be used in a high-pressure environment.

[0028] (3) In the first embodiment, a top cut method is used to form a hole having a diameter smaller than that of the water pipe K (fluid pipe) using a cylindrical cutter 4 having a diameter smaller than that of the water pipe K (fluid pipe). However, the method is not limited to the top cut method, and the cutter 4 may cut the water pipe K (fluid pipe) all the way to its lower end. In this case, a so-called full cut method may be adopted in which a cylindrical cutter 4 having a diameter larger than that of the water pipe K (fluid pipe) is used to cut the water pipe K from its upper end to its lower end.

[0029] (4) The present invention is not limited to the top-cut method of the first embodiment, and may be configured such that, for example, the lowest end of the portion of the water pipe K (fluid pipe) to be cut is positioned above the pipe axis (AD1). For example, a so-called half-cut method may be adopted in which only one of the left and right sides of the water pipe K is cut out with a cylindrical cutter 4 facing downward.

[0030] (5) In the first embodiment, as shown in FIG. 5, the storage box 3, the cutter 4, the extension shaft 5 and the slide pipe 6 are lifted by a crane in an integrated state without connecting the drilling machine 7, but they may also be lifted by a crane with the drilling machine 7 further connected.

[0031] (6) In the first embodiment, as shown in FIG. 12, the storage box 3, the cutter 4, the extension shaft 5 and the slide pipe 6 are lifted by a crane in an integrated state without connecting the drilling machine 7, but they may also be lifted by a crane with the drilling machine 7 further connected.

[0032] (7) In the first embodiment, the holes are drilled in the vertical direction, but this is not limiting. For example, the holes may be drilled in the horizontal direction.

[0033] (8) In the first embodiment, the fluid pipe is a water pipe K, but is not limited to this.

[0034] As described above, although not particularly limited, as in the first embodiment or modified example, the fluid pipe drilling method may include connecting a gate valve 2 to an outer case 1 attached to a water pipe K (fluid pipe) and opening the gate valve 2, preparing an extension shaft 5 connected to a cutter 4 for cutting the water pipe K (fluid pipe), a slide pipe 6 into which the extension shaft 5 is inserted, and a storage box 3 in which the slide pipe 6 is attached so that it can be displaced between the outside and the inside, connecting the storage box 3 to the outer case 1 via the gate valve 2 with the slide pipe 6 into which the extension shaft 5 is inserted extended inward, attaching a drilling machine 7 to the outside of the storage box 3 and connecting the shaft 70 of the drilling machine 7 to the extension shaft 5, advancing the shaft 70 of the drilling machine 7 so that the extension shaft 5 protrudes from the slide pipe 6, and advancing the cutter 4 toward the water pipe K (fluid pipe) to drill the water pipe K (fluid pipe). In this way, since the gate valve 2 is in the open state and the water pipe K (fluid pipe) has not yet been drilled, the storage box 3 can be connected to the outer box 1 with the slide pipe 6 extended from the storage box 3. Therefore, the step of extending the slide pipe 6 from the storage box 3 can be omitted.

[0035] Although not particularly limited, as in the first embodiment or modified example, after drilling, the extension shaft 5 may be returned from a state in which it protrudes from the slide pipe 6 to a state in which it is inserted into the slide pipe 6, the slide pipe 6 with the extension shaft 5 inserted therein may be returned to a state in which it is displaced outward from the storage box 3, the check valve 2 may be closed, and the storage box 3 may be removed from the check valve 2. In this way, the cutter 4, extension shaft 5, slide pipe 6 and storage box 3 are integrated, so that these devices can be easily recovered at the site.

[0036] Although not particularly limited, as in the first embodiment or modified example, a screw jack 9 that can change the distance between the storage box 3 and the slide pipe 6 may be connected to the storage box 3 and the slide pipe 6, the fastener 67 that secures the storage box 3 and the slide pipe 6 may be removed, and the slide pipe 6 may be displaced outward from the storage box 3 while controlling the distance between the storage box 3 and the slide pipe 6 with the screw jack 9. In this way, it is possible to prevent the slide pipe 6 from being suddenly displaced outward due to the water pressure (internal pressure) of the water pipe K (fluid pipe). Conversely, if the water pressure (internal pressure) of the water pipe K (fluid pipe) is insufficient, it is possible to safely displace the slide pipe 6, which is a heavy object, outward.

[0037] Although not particularly limited, as in the first embodiment or the modified example, the outer box 1 may have a branch pipe section 10 that branches off a flow path from the water pipe K (fluid pipe), and the branch pipe section 10 may be located above the pipe axis (AD1) of the water pipe K (fluid pipe). Since the opening 12 of the outer box 1 faces upward and the branch pipe section 10 is located above the pipe axis of the water pipe K, it is suitable for the so-called top cut construction method in which only the upper part of the water pipe K is drilled and not the lower part.

[0038] Although not particularly limited, as in a modified example, the cutter 4 may cut the water pipe K (fluid pipe) down to its lower end. This is suitable for the so-called full cut method.

[0039] Although not particularly limited, as in a modified example, the lowest end of the portion of the water pipe K (fluid pipe) to be cut may be positioned below the pipe axis (AD1). This is suitable for the so-called half-cut method.

[0040] Although not particularly limited, as in the first embodiment or modified example, after removing the storage box 3, an inner plug 13 that contacts the inner surface of the outer box 1 may be attached, and after attaching the inner plug 13, the lid 14 of the outer box 1 may be attached. This is particularly effective when the opening 12 of the outer box 1 has a large diameter.

[0041] Although not particularly limited, as in a modified example of the first embodiment, the inner plug 13 may have a ring portion 13a that is sealed against the inner surface of the outer box 1 via a sealing material 13c, and a top portion 13b that covers the center of the ring portion 13a, and the top portion 13b may have an arc portion 13d that protrudes inward from the outer box 1 in a cross section passing through the axis (AD2) of the ring portion 13a. The arc portion 13d improves the strength of the inside plug 13, making it possible to use it in a high-pressure environment. It can also be said to be a plug attachment method for a fluid pipe having an outer case 1 attached to a water pipe K (fluid pipe) and an inner plug 13 inserted into the outer case 1 through an opening 12 of the outer case 1.

[0042] Although the embodiments of the present disclosure have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present disclosure is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.

[0043] The structures employed in the above-described embodiments can be employed in any other embodiment. The specific configurations of the components are not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0044] K...Water pipe (fluid pipe) 1...Outer box 2...Gate valve 3...Storage box 4...Cutter 5...Extension shaft 6...Slide pipe 7…Drilling machine 9...Screw jack 10...Branch pipe section 13...Inner stopper 13a...Ring section 13b...Top

Claims

1. a gate valve connected to an outer case attached to the fluid pipe and set to an open state; an extension shaft connected to a cutter for cutting the fluid pipe; a slide pipe into which the extension shaft is inserted and which supports the extension shaft in an inserted state so that the extension shaft can be displaced between an outer position and an inner position; and a storage box in which the slide pipe is mounted so that the slide pipe can be displaced between an outer position and an inner position. When the slide pipe is in the outer position, the tip of the cutter including the center drill is outward from the inner end opening of the storage box, and when the slide pipe is in the inner position, the tip of the cutter protrudes inward from the inner end opening of the storage box, The slide pipe into which the extension shaft is inserted is extended to the inner position, and the slide pipe and the storage box are fixed together with a fastener. The container box is connected to the outer box via the gate valve with the tip of the cutter positioned inward of the gate valve and outward of the fluid pipe; A drilling machine is attached to the outside of the storage box, and the shaft of the drilling machine is connected to the extension shaft; A fluid pipe drilling method comprising: advancing the shaft of the drilling machine to cause the extension shaft to protrude from the slide pipe; and advancing the cutter toward the fluid pipe to drill the fluid pipe.

2. After drilling, the extension shaft is returned from a state in which it protrudes from the slide pipe to a state in which it is inserted into the slide pipe, The slide pipe into which the extension shaft is inserted is returned to the state displaced outward from the storage box, The method of claim 1 , further comprising closing the gate valve and removing the container from the gate valve.

3. A screw jack capable of varying the distance between the storage box and the slide pipe is connected to the storage box and the slide pipe, 3. The method according to claim 1, further comprising removing a fastener that fixes the storage box and the slide pipe, and displacing the slide pipe outward from the storage box while controlling the distance between the storage box and the slide pipe with the screw jack.

4. the outer box has a branch pipe portion that branches a flow path from the fluid pipe, The method according to any one of claims 1 to 3, wherein the branch pipe portion is located above the pipe axis of the fluid pipe.

5. The method according to any one of claims 1 to 4, wherein the cutter cuts the fluid pipe to its lower end.

6. The method according to any one of claims 1 to 4, wherein the lowermost end of the portion of the fluid pipe to be cut is located below the pipe axis.

7. After removing the container box, an inner plug is attached to the outer box so as to contact the inner peripheral surface of the outer box. The method according to any one of claims 1 to 6, wherein a lid is attached to the outer box after the inner plug is attached.

8. The inside plug has a ring portion that is sealed to the inner peripheral surface of the outer box via a sealing material, and a top portion that covers the center of the ring portion, The method according to claim 7 , wherein the top portion has an arcuate portion that protrudes inwardly of the outer box in a cross section passing through the axis of the ring portion.

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