Fluid pipe cutting method and fluid pipe cutting apparatus

Abstract

The present invention provides a fluid pipe cutting method and a fluid pipe cutting apparatus that can confirm whether or not the fluid pipe has been cut while avoiding damage to the sealing performance of the valve body. [Solution] The fluid pipe cutting method includes an installation step of arranging a valve body 2 so as to cover the cutting location 10 of the fluid pipe 1, attaching a work valve 3 for opening and closing the upper opening 22 of the valve body 2 to the top of the valve body 2, and attaching a drilling machine 4 to the top of the work valve 3, and a cutting step after the installation step of inserting the cutter 40 of the drilling machine 4 into the valve body 2 through the upper opening 22 of the valve body 2 and cutting the fluid pipe 1 with the cutter 40, and the cutting step includes detecting changes in the load applied to the drilling machine 4, the work valve 3 or the valve body 2 with a sensor 7.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for cutting a fluid pipe through which a fluid such as Coke Oven Gas (COG) flows.

Background Art

[0002] As disclosed in Patent Documents 1, 2, etc. below, there is known a method of cutting an existing fluid pipe in a non-stop flow state (without interrupting the flow of the fluid).

[0003] Patent Document 1 discloses a perforator configured to be detachably attached to a valve box configured to be attached around a pipe for Coke Oven Gas. The perforator has a cylindrical perforating blade and a center drill disposed inside the perforating blade. A locking member is attached to the center drill. After cutting the pipe in the valve box with the perforating blade and the center drill, the cut piece is locked to the locking member and carried out of the valve box together with the perforating blade and the center drill.

[0004] Patent Document 2 discloses attaching a valve box around a pipe so that the pipe for Coke Oven Gas and a receiving seat fixed to the bottom wall of the valve box are separated. The receiving seat is configured such that the pipe does not contact it when the pipe is cut by the perforating blade, but receives the cut piece of the pipe when the cut piece of the pipe cut by the perforating blade falls from the center drill. Patent Document 2 also discloses disposing a slack string-like member between the bottom wall of the valve box and the pipe before cutting the pipe, applying tension to the string-like member from outside the valve box after cutting the pipe, and detecting whether or not the cut piece has fallen onto the receiving seat based on the magnitude of the tension generated in the string-like member at that time or the amount of pulling of the string-like member at that time.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In the above-mentioned method for cutting fluid pipes, the fluid pipe (piping) is cut inside the valve body, making it difficult to confirm from the outside whether the cutting is complete or not. As disclosed in Patent Document 2, it is conceivable to confirm whether the cutting is complete or not by manipulating a string-like member or the like from outside the valve body, but this would require providing a through-hole in the valve body for inserting such a member, and there is a risk that the sealing performance of the valve body may be impaired by the through-hole.

[0007] The present invention was made to solve the above-mentioned problems, and one of its objectives is to provide a fluid pipe cutting method and a fluid pipe cutting apparatus that can confirm whether or not the cutting of the fluid pipe has been completed while avoiding damage to the sealing performance of the valve body. [Means for solving the problem]

[0008] The inventors of this invention investigated a technique for confirming whether the cutting of a fluid pipe has been completed while avoiding damage to the sealing performance of the valve body. In the process, they discovered a new finding that changes occur in the load applied to the drilling machine, the work valve, and the valve body before and after the cutting of the fluid pipe, and that it is possible to confirm whether the cutting of the fluid pipe has been completed from these changes in load. This invention was made based on this finding.

[0009] In one embodiment, the fluid pipe cutting method according to the present invention is as follows: The installation process includes arranging the valve body to cover the cut portion of the fluid pipe, attaching a work valve to the top of the valve body for opening and closing the upper opening of the valve body, and attaching a drilling machine to the top of the work valve; and, after the installation process, inserting the cutter of the drilling machine into the valve body through the upper opening of the valve body and cutting the fluid pipe with the cutter, wherein the cutting process includes detecting changes in the load applied to the drilling machine, work valve, or valve body using sensors.

[0010] In one embodiment, the fluid pipe cutting device according to the present invention comprises a valve body attached to the fluid pipe so as to cover the cutting point of the fluid pipe; a work valve attached to the upper part of the valve body for opening and closing the upper opening of the valve body; a drilling machine attached to the upper part of the work valve and having a cutter that enters the valve body through the upper opening of the valve body to cut the fluid pipe; and a sensor for detecting changes in the load applied to the drilling machine, the work valve, or the valve body. [Effects of the Invention]

[0011] According to one embodiment of the fluid pipe cutting method and fluid pipe cutting apparatus of the present invention, a sensor detects changes in the load applied to the drilling machine, work valve, or valve body, making it possible to confirm whether or not the fluid pipe cutting is complete while avoiding damage to the sealing performance of the valve body. [Brief explanation of the drawing]

[0012] [Figure 1] This is a front view showing a fluid pipe cutting device according to Embodiment 1 of the present invention. [Figure 2] Figure 1 is a right side view of the fluid pipe cutting device. [Figure 3] Figure 1 is a perspective view showing the valve body. [Figure 4] Figure 1 is an explanatory diagram showing how the section generated by cutting the fluid pipe is being lifted up together with the cutter. [Figure 5] This is a schematic diagram illustrating how the load is transmitted to the section of a fluid pipe after it has been cut. [Figure 6] This is an explanatory diagram showing a magnified view of the sensor and its surroundings in a partial cross-section, as shown in Figure 1. [Figure 7] This is a front view showing a fluid pipe cutting device according to Embodiment 2 of the present invention. [Figure 8] Figure 7 is a schematic diagram illustrating the load on the fluid pipe before it is cut. [Figure 9] Figure 7 is a schematic diagram illustrating the load after the fluid pipe has been cut. [Figure 10]It is an explanatory diagram schematically showing how the load is transmitted through a section of a fluid pipe after the fluid pipe is cut. [Figure 11] It is a front view showing a fluid pipe cutting device according to Embodiment 3 of the present invention.

Embodiments for Carrying out the Invention

[0013] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components of different embodiments may be appropriately combined.

[0014] <Regarding the fluid pipe cutting device> Embodiment 1. FIG. 1 is a front view showing a fluid pipe cutting device according to Embodiment 1 of the present invention, FIG. 2 is a right side view of the fluid pipe cutting device of FIG. 1, FIG. 3 is a perspective view showing the valve box 2 of FIG. 1, FIG. 4 is an explanatory diagram showing a state where a section 10a generated by cutting the fluid pipe 1 of FIG. 1 is pulled up together with the cutter 40, and FIG. 5 is an explanatory diagram schematically showing how the load is transmitted through the section 10a of the fluid pipe 1 after the fluid pipe 1 is cut. Note that FIG. 2 also shows a cross section of the fluid pipe 1 etc. along the line II-II of FIG. 1.

[0015] The fluid pipe cutting device of the present embodiment is a device for cutting a fluid pipe 1 through which a fluid flows. Although not limited, the fluid pipe cutting device of the present embodiment can be used for cutting a fluid pipe 1 for coke oven gas. The fluid pipe 1 for coke oven gas can be a metal circular pipe having an outer diameter of about 800 mm to 3000 mm and a wall thickness of about 4 mm to 9 mm. Examples of the metal constituting the fluid pipe 1 include carbon steel or stainless steel etc.

[0016] For example, during the renovation work of a coke oven, a part of the existing fluid pipe 1 may be cut (without interrupting the flow of coke oven gas) and a shut-off valve may be provided at the cut location while maintaining a continuous flow state. Although not limited, the fluid pipe cutting device of the present embodiment can be used when cutting a part of the fluid pipe 1 for such a purpose. In FIG. 1, the fluid pipe 1 extends linearly in the horizontal direction. The fluid pipe 1 may extend obliquely with respect to the horizontal direction. And a part of this fluid pipe 1 is scheduled to be cut. In FIG. 1, a part of the fluid pipe 1 located inside the valve box 2 to be described later is scheduled to be cut. In FIG. 1, the location of the fluid pipe 1 scheduled to be cut (hereinafter also referred to as "cut location 10") located inside the valve box 2 to be described later is emphasized and shown by shading.

[0017] As shown in FIGS. 1 and 2, the fluid pipe cutting device of the present embodiment includes a valve box 2, a working valve 3, a drilling machine 4, a first support 5, a second support 6, and a sensor 7.

[0018] The valve box 2 is attached to the fluid pipe 1 so as to cover (wrap) the cut location 10 of the fluid pipe 1, and after the cut location 10 is cut, it prevents the fluid flowing inside the fluid pipe 1 from flowing out (leaking) to the outside.

[0019] The valve box 2 has a lower valve box 20 disposed below the fluid pipe 1 and an upper valve box 21 disposed above the fluid pipe 1 as shown in the illustrated embodiment. The lower valve box 20 and the upper valve box 21 are disposed so as to cover (wrap) the cut location 10 of the fluid pipe 1.

[0020] The lower valve box 20 has a housing portion 201 and a pair of arc portions 202. The housing portion 201 has a bottomed cylindrical shape that is open upward, and has a cylindrical side wall 201a and a disc-shaped bottom wall 201b. The pair of arc portions 202 are located on both sides of the housing portion 201 and each have a concave arc shape facing upward. The housing portion 201 and the arc portion 202 are integrally formed.

[0021] The upper valve box 21 has a housing portion 211 and a pair of arc portions 212. The housing portion 211 has a cylindrical shape that is open at the top and bottom, and has a cylindrical side wall 211a with the same diameter as the side wall 201a described above. The pair of arc portions 212 are connected to both sides of the housing portion 211, similar to the arc portion 202 of the lower valve box 20 described above. In short, the upper valve box 21 is the same shape as the lower valve box 20 but inverted in the vertical direction of the drawing, except that it does not have a bottom wall 201b.

[0022] As shown in Figures 1 to 3, when the lower end of the upper valve box 21 abuts against the upper end of the lower valve box 20, the housing portion 201 and the housing portion 211 as a whole form a bottomed cylindrical housing portion that is open upwards. An upper opening 22 is provided at the top of the housing portion. The housing portion is sized so that the fluid pipe 1 passes through it horizontally and the cutter 40 of the drilling machine 4, described later, passes through it vertically.

[0023] Furthermore, when the lower end of the upper valve box 21 abuts against the upper end of the lower valve box 20, the arc portion 202 and the arc portion 212 as a whole form a cylindrical shape extending laterally from the housing portion, enclosing the outer circumference of the fluid pipe 1 (covering the outer circumference of the fluid pipe 1).

[0024] The upper end of the lower valve box 20 and the lower end of the upper valve box 21 are joined to each other by a method such as welding, with the ends butted against each other.

[0025] The tip portions of the arc-shaped sections 202 and 212 (the ends that are away from the housing) are joined to the outer surface of the fluid pipe 1, for example, by welding.

[0026] The work valve 3 is mounted on the top of the valve body 2 and opens and closes the upper opening 22 of the valve body 2.

[0027] The work valve 3 comprises a work valve housing 30 attached to the valve body 2, a valve body 31 housed within the work valve housing 30, and a work valve actuator 32 connected to the valve body 31. The valve body 31 is configured to slide between a position that closes the upper opening 22 and a position that is detached from the upper opening 22 by the driving force of the work valve actuator 32. When the upper opening 22 is closed by the valve body 31, the inside of the valve body 2 becomes airtight.

[0028] The upper end of the valve body 2 and the lower end of the work valve 3 are provided with a valve body upper end flange 23 and a work valve lower end flange 33, respectively. The valve body upper end flange 23 and the work valve lower end flange 33 are butted against each other and joined together, for example, by bolts and nuts.

[0029] The drilling machine 4 is mounted on top of the work valve 3. The drilling machine 4 has a cutter 40 that enters the valve body 2 through the upper opening 22 of the valve body 2 and cuts the fluid pipe 1. The cutter 40 enters the valve body 2 when the valve body 31 of the work valve 3 is detached from the upper opening 22 of the valve body 2.

[0030] The drilling machine 4 includes a drilling machine housing 41 mounted on top of the work valve 3, and a drilling machine actuator 42 mounted on top of the drilling machine housing 41. The cutter 40 is housed within the drilling machine housing 41 so as to be able to move vertically back and forth. The cutter 40 moves vertically back and forth and is also rotationally driven by the driving force of the drilling machine actuator 42.

[0031] The cutter 40 has a shaft member 400 connected to the drilling machine actuator 42, and a center drill 401 and a drilling blade 402 connected to the lower part of the shaft member 400.

[0032] The shaft member 400 is a vertically extending shaft, and the driving force of the drilling machine actuator 42 is transmitted to the center drill 401 and the drilling blade 402 through the shaft member 400. The shaft member 400 moves vertically and rotates together with the center drill 401 and the drilling blade 402.

[0033] The center drill 401 is configured to puncture the fluid pipe 1. Therefore, as shown particularly in Figure 4, the lower end of the center drill 401 is sharpened. The upper end of the center drill 401 is connected to the lower end of the shaft member 400.

[0034] As shown in Figures 1 and 2, the drilling blade 402 has a cylindrical blade body 402a and a disc-shaped top wall 402b. The blade body 402a extends vertically and is positioned to surround the center drill 401. In other words, the center drill 401 extends in the direction of the blade body 402a and is located within the blade body 402a. Although not shown, the cylindrical wall of the blade body 402a may have multiple through holes. The through holes have the function of preventing the fluid flowing through the fluid pipe 1 from being blocked by the cylindrical wall of the blade body 402a when the fluid pipe 1 is cut by the blade body 402a. The top wall 402b closes the upper end of the blade body 402a and is fixed to the lower end of the shaft member 400. That is, the top wall 402b connects the blade body 402a and the shaft member 400.

[0035] The cutter 40 has a segment holding section 43 that holds the segment 10a (the segment that is cut off from the fluid pipe at the cutting point 10; see Figure 4) generated when the fluid pipe 1 is cut. Therefore, the segment 10a generated when the fluid pipe 1 is cut can be held in the segment holding section 43 and transported out of the fluid pipe 1 together with the cutter 40 (see Figure 4). Any configuration can be used for the segment holding section 43.

[0036] The illustrated piercing machine housing 41 has a first portion 411 attached to the top of the work valve 3, a second portion 412 attached to the top of the first portion 411, a third portion 413 attached to the top of the second portion 412, and a fourth portion 414 attached to the top of the third portion 413. A piercing machine actuator 42 is attached to the top of the fourth portion 414, and a shaft member 400 passes through the fourth portion 414, the third portion 413, the second portion 412, and the first portion 411. The first portion 411 has a larger diameter than the other portions (second portion 412, third portion 413, and fourth portion 414) to house the piercing blade 402 of the cutter 40.

[0037] The upper end of the work valve 3 and the lower end of the first portion 411 are provided with an upper flange 34 and a lower flange 411a of the first portion, respectively. The upper flange 34 and the lower flange 411a of the work valve are joined to each other, for example, by bolts and nuts, in a butted state.

[0038] Similarly, the upper end of the first portion 411 and the lower end of the second portion 412 are provided with the upper flange 411b and lower flange 412a of the second portion, respectively. The upper flange 411b and lower flange 412a of the first portion are joined to each other, for example, by bolts and nuts, in a butted state.

[0039] Similarly, the upper end of the second portion 412 and the lower end of the third portion 413 are provided with the upper flange 412b and lower flange 413a of the second portion, respectively. The upper flange 412b and lower flange 413a of the second portion are joined to each other, for example, by bolts and nuts, in a butted state.

[0040] Similarly, the upper end of the third section 413 and the lower end of the fourth section 414 are provided with the upper flange 413b and lower flange 414a of the fourth section, respectively. The upper flange 413b and lower flange 414a of the third section are joined to each other, for example, by bolts and nuts, in a butted state. Height adjustment fittings, packings, gaskets, etc., for adjusting the stroke of the cutter 40 may be sandwiched between the upper and lower flanges as described above. For example, a ring-shaped fitting may be sandwiched between the upper and lower flanges.

[0041] The valve body 2, work valve 3, and drilling machine 4 together have a weight of approximately 40,000 kg. By supporting the fluid pipe 1 on which the valve body 2, work valve 3, and drilling machine 4 are placed using the first support 5 and the second support 6, the load on the fluid pipe 1 when it is cut can be reduced.

[0042] The first support 5 is positioned below the fluid pipe 1 on both sides of the cut section 10, and supports the fluid pipe 1.

[0043] The second support 6 is positioned below the valve body 2 and supports the valve body 2, the work valve 3, and the drilling machine 4. The second support 6 has a plurality of pieces 60, as shown in Figures 1 and 2, for example.

[0044] In the illustrated embodiment, the first support 5 and the second support 6 are placed on a support base 80. The support base 80 is supported on a support surface 82, such as the ground, via a plurality of support columns 81.

[0045] Sensor 7 detects changes in the load applied to the drilling machine 4, the work valve 3, or the valve body 2. As shown in Figure 5, after the fluid pipe 1 is cut, the resulting piece 10a is suspended from the cutter 40. The cutter 40 is supported by a drilling machine actuator 42 located on the top of the drilling machine housing 41, and the drilling machine housing 41 is supported by the work valve 3 and the valve body 2. Therefore, the load of the piece 10a, which was not applied before the fluid pipe 1 was cut, is applied to the drilling machine 4 (cutter 40, drilling machine actuator 42, and drilling machine housing 41), the work valve 3, and the valve body 2 after the fluid pipe 1 is cut. By detecting the increase in the load applied to the drilling machine 4, the work valve 3, or the valve body 2 using sensor 7, it is possible to confirm that the cutting of the fluid pipe 1 is complete. In the configuration disclosed in Patent Document 2, a member for confirming the completion of cutting is inserted into the valve body 2 and operated, so it is necessary to provide a through hole in the valve body 2 for inserting such a member into the valve body 2, and there is a risk that the sealing performance of the valve body 2 will be impaired by the through hole. In contrast, the device of this embodiment can confirm whether or not the cutting of the fluid pipe 1 is complete while avoiding impairment of the sealing performance of the valve body 2.

[0046] Any configuration of sensor 7 capable of detecting load, such as a load cell, may be used. Sensor 7 may output the average value of the detected load within a predetermined time. Load detection by sensor 7 is preferably performed when the cutter 40 is stopped in order to suppress the effects of vibrations associated with the operation (rotation and reciprocation) of the cutter 40. For example, after operating the cutter 40 and advancing the cutting of the fluid pipe 1 to a certain extent, the operation of the cutter 40 is stopped and load detection is performed by sensor 7. At this time, if the completion of cutting the fluid pipe 1 cannot be confirmed by load detection, the operation of the cutter 40 and the cutting of the fluid pipe 1 are restarted. Then, load detection by sensor 7 is performed each time the operation of the cutter 40 is stopped, and the restart of cutting the fluid pipe 1 and load detection are repeated until the completion of cutting the fluid pipe 1 can be confirmed.

[0047] The sensor 7 is preferably attached to the drilling machine 4, the work valve 3, or the valve box 2. Placing the sensor 7 in such a position has the advantage of being able to detect whether the section 10a is properly suspended from the cutter 40.

[0048] The load of the section 10a suspended from the cutter 40 is transmitted to the valve body 2 through the drilling machine 4 and the work valve 3. If a sensor 7 were attached to the valve body 2, the sensor 7 would detect that the load of the section 10a (approximately 700 kg) is added to the weight of the valve body 2, the work valve 3, and the drilling machine 4 (approximately 40,000 kg in total). In contrast, if the sensor 7 were attached to the drilling machine 4, the sensor 7 would detect that the load of the section 10a is added to the weight of the drilling machine 4 alone. Compared to the former, the latter has a greater influence from the load of the section 10a, and the accuracy of the sensor 7's detection of changes in the support load can be improved. From this point of view, it is more preferable that the sensor 7 be positioned closer to the support point (drilling machine actuator 42) of the cutter 40 from which the section 10a is suspended. That is, it is more preferable that the sensor 7 be attached to the drilling machine 4 or the work valve 3, and even more preferable that it be attached to the drilling machine 4.

[0049] It is more preferable that the sensor 7 is attached to the outer surface of the drilling machine 4, the work valve 3, or the valve body 2. By attaching the sensor 7 to the outer surface of the valve body 2, etc., contact between the sensor 7 and the fluid can be avoided. Furthermore, it is possible to avoid exposing the sensor 7 to high-temperature and corrosive environments. In addition, the need to significantly modify the existing valve body 2, etc. can be reduced.

[0050] It is even more preferable that the sensor 7 is attached to the flange of the drilling machine 4, the work valve 3, or the valve body 2. This is because, when attaching the sensor 7 to the valve body 2, the work valve 3, and the drilling machine 4 from the side, the flange provides sufficient depth for attaching the sensor 7.

[0051] Based on the above considerations, Figures 1 and 2 show an embodiment in which the sensor 7 is attached to the lower end flange 414a of the fourth section of the drilling machine 4. However, the attachment location of the sensor 7 is not limited to the embodiments shown in Figures 1 and 2, and the sensor 7 may be attached to other locations. For example, the sensor 7 may be attached to the upper end flange 413b of the third section, the lower end flange 413a of the third section, the upper end flange 412b of the second section, the lower end flange 412a of the second section, the upper end flange 411b of the first section, the lower end flange 411a of the first section, the upper end flange 34 of the work valve, the lower end flange 33 of the work valve, or the upper end flange 23 of the valve body in the embodiments shown in Figures 1 and 2. If a height adjustment fitting or the like is sandwiched between the upper and lower flanges, the sensor 7 may be attached to the height adjustment fitting or the like. In the present invention, the statement that the sensor 7 is attached to the flange includes cases in which the sensor 7 is attached to a member such as a height adjustment fitting that is arranged in a manner sandwiched between the upper and lower flanges. Furthermore, if the walls of the valve body 2, work valve 3, and drilling machine 4 have sufficient thickness, the sensor 7 may be attached to the walls of the valve body 2, work valve 3, and drilling machine 4 other than the flange.

[0052] Next, Figure 6 is an explanatory diagram of a partial cross-section showing an enlarged view of the sensor 7 and its surroundings in Figure 1. In Figure 6, the sensor 7 has a shaft 70 inserted into a hole 9 provided on the outer surface of the lower end flange 414a of the fourth part of the drilling machine 4, and a detection unit 71 that detects the strain of the shaft 70. When the section 10a is suspended from the cutter 40 and the load of the section 10a acts on the valve body 2, the work valve 3, and the drilling machine 4, strain occurs in the shaft 70. By detecting the strain of the shaft 70, the load of the section 10a acting on the valve body 2, the work valve 3, and the drilling machine 4 can be detected by the detection unit 71. Although not limited to these, examples of such a sensor 7 include a piezoelectric strain sensor manufactured by Kyowa Electric Industry Co., Ltd. When the sensor 7 is attached to the walls of the valve body 2, work valve 3, and drilling machine 4 other than the flange, the hole 9 into which the shaft 70 is inserted is provided on the outer surface of the walls of those valve body 2, work valve 3, and drilling machine 4.

[0053] Embodiment 2. Figure 7 is a front view showing a fluid pipe cutting device according to Embodiment 2 of the present invention. In Embodiment 1, it was described that a change in the load applied to the drilling machine 4, the work valve 3, or the valve body 2 is detected by the sensor 7. However, the change in the load applied to the first support 5 or the second support 6 may also be detected by the sensor 7. In the embodiment shown in Figure 7, the sensor 7 is attached to the second support 6, and the change in the load applied to the second support 6 is detected by the sensor 7. Although not shown, the sensor 7 may also be attached to the first support 5, and the change in the load applied to the first support 5 may be detected by the sensor 7.

[0054] Next, Figure 8 is a schematic diagram illustrating the load on the fluid pipe 1 before cutting in Figure 7, Figure 9 is a schematic diagram illustrating the load on the fluid pipe 1 after cutting in Figure 7, and Figure 10 is a schematic diagram illustrating how the load is transmitted to the section 10a of the fluid pipe 1 after cutting.

[0055] As shown in Figure 8, before the fluid pipe 1 is cut, the first support 5 supports the fluid pipe 1, and the second support 6 supports the valve body 2, the work valve 3, and the drilling machine 4. At this time, the majority of the weight of the cut portion 10 of the fluid pipe 1 is supported by the first support 5.

[0056] On the other hand, as shown in Figures 9 and 10, after the fluid pipe 1 is cut, the resulting section 10a is suspended from the cutter 40. The cutter 40 is supported by a drilling machine actuator 42 located on the top of the drilling machine housing 41, and the drilling machine housing 41 is supported by a second support 6 through the work valve 3 and valve body 2. Therefore, after the fluid pipe 1 is cut, most of the load on the section 10a is supported by the second support 6 through the drilling machine 4, work valve 3 and valve body 2. A portion of the load on the section 10a may be transmitted to the first support 5 through the joint between the arc portion 202 and arc portion 212 of the valve body 2 and the fluid pipe 1, but since the rigidity of the valve body 2 is far superior to that of the fluid pipe 1, support by the second support 6 is dominant.

[0057] Thus, the proportion of the load borne by the first support 5 and the second support 6 on the cut portion 10 (section 10a) of the fluid pipe 1 changes before and after the fluid pipe 1 is cut. Specifically, the load on the second support 6 increases after the fluid pipe 1 is cut, while the load on the first support 5 decreases. Therefore, by attaching a sensor 7 to the first support 5 or the second support 6 and detecting the change in load on the first support 5 or the second support 6 with the sensor 7, it is possible to confirm whether or not the cutting of the fluid pipe 1 has been completed.

[0058] Embodiment 3. Figure 11 is a front view showing a fluid pipe cutting device according to Embodiment 3 of the present invention. The sensor 7 may be positioned between the first support 5 and the fluid pipe 1, between the second support 6 and the valve body 2, between the support base 80 supporting the first support 5 and the second support 6 and the lower surface of the first support 5, or between the support base 80 and the lower surface of the second support 6. Even when the sensor 7 is positioned in this way, the sensor 7 can detect changes in the load applied to the first support 5 or the second support 6. Figure 11 shows an embodiment in which the sensor 7 is positioned between the first support 5 and the fluid pipe 1. Although not limited to this, examples of sensors 7 to be positioned in this way include a type compression load cell sensor manufactured by MinebeaMitsu. The other configurations are the same as in Embodiments 1 and 2.

[0059] <Regarding methods for cutting fluid pipes> The fluid pipe cutting method according to an embodiment of the present invention includes an installation step of arranging a valve body 2 so as to cover the cutting location 10 of the fluid pipe 1, attaching a work valve 3 for opening and closing the upper opening 22 of the valve body 2 to the upper part of the valve body 2, and attaching a drilling machine 4 to the upper part of the work valve 3; and a cutting step after the installation step of inserting the cutter 40 of the drilling machine 4 into the valve body 2 through the upper opening 22 of the valve body 2 and cutting the fluid pipe 1 with the cutter 40, wherein the cutting step includes detecting changes in the load applied to the drilling machine 4, the work valve 3, or the valve body 2 using a sensor 7. The installation step may also include attaching first support members 5 to support the fluid pipe 1 below the fluid pipe 1 on both sides of the cutting location 10, and attaching second support members 6 to support the valve body 2, the work valve 3, and the drilling machine 4 below the valve body 2, and the sensor 7 may detect changes in the load applied to the first support member 5 or the second support member 6. Details of each configuration, including, for example, the position of the sensor 7 and the method of detecting the load by the sensor 7, are as described in the fluid pipe cutting device described above.

[0060] Although preferred embodiments of the present invention have been described in detail above with reference to the attached drawings, the present invention is not limited to these examples. It is clear to any person with ordinary skill in the art to which the present invention belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these are also understood to fall within the technical scope of the present invention.

[0061] For example, in the embodiment, it was described that a first support 5 is attached below the fluid pipe 1 on both sides of the cutting point 10 to support the fluid pipe 1, and a second support 6 is attached below the valve body 2 to support the valve body 2, the work valve 3, and the drilling machine 4. However, these first support 5 and second support 6 may be omitted. [Explanation of Symbols]

[0062] 1:Fluid tube 2: Valve box 22: Upper opening 3: Work valve 4:Drilling machine 40: Cutter 5: First support 6:Second support 7: Sensor 70: Axis 71: Detection unit 82: Support surface 9: Hole 10: Cutting point

Claims

1. The installation process involves positioning a valve body to cover the cut portion of the fluid pipe, attaching a work valve to the top of the valve body for opening and closing the upper opening of the valve body, and attaching a drilling machine to the top of the work valve. After the installation step, a cutting step is performed in which the cutter of the drilling machine is inserted into the valve body through the upper opening of the valve body, and the fluid pipe is cut by the cutter. Includes, The cutting step includes detecting changes in the load applied to the drilling machine, the work valve, or the valve body using a sensor. Fluid pipe cutting method.

2. The sensor is attached to the drilling machine, the work valve, or the valve box. The method for cutting a fluid pipe according to claim 1.

3. The sensor is attached to the outer surface of the drilling machine, the work valve, or the valve box. The method for cutting a fluid pipe according to claim 2.

4. The sensor is attached to the flange of the drilling machine, the work valve, or the valve body. The method for cutting a fluid pipe according to claim 3.

5. The sensor comprises a shaft inserted into a hole provided on the outer surface of the drilling machine, the work valve, or the valve body, and a detection unit for detecting the strain of the shaft. A method for cutting a fluid pipe according to any one of claims 2 to 4.

6. The mounting step includes attaching a first support to support the fluid pipe below the fluid pipe on both sides of the cutting location, and attaching a second support to support the valve box, the work valve, and the drilling machine below the valve box. The sensor detects changes in the load applied to the first support or the second support. The method for cutting a fluid pipe according to claim 1.

7. A valve body attached to the fluid pipe so as to cover the cut portion of the fluid pipe, A work valve is attached to the upper part of the valve body for opening and closing the upper opening of the valve body, A drilling machine having a cutter attached to the upper part of the work valve, which enters the valve body through the upper opening of the valve body and cuts the fluid pipe, A sensor that detects changes in the load applied to the drilling machine, the work valve, or the valve body, Equipped with, Fluid pipe cutting device.

8. A first support is positioned below the fluid pipe on both sides of the cut portion to support the fluid pipe, A second support is positioned below the valve box and supports the valve box, the work valve, and the drilling machine. Furthermore, The sensor detects changes in the load applied to the first support or the second support. The fluid pipe cutting device according to claim 7.

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