Pipe cutting method, pipe cutting device, and method for controlling said pipe cutting device

Abstract

To provide a piping cutting method which can process piping without causing a malfunction with respect to existing piping in which a protection member is arranged so as to cover a diameter outside part of the piping, a piping cutter and a control method of the piping cutter.SOLUTION: A piping cutting method of this invention using a piping cutter having a cutting part 13 for cutting a wall thickness of piping at existing piping 8 in which a protection material 9 is arranged so as to cover a diameter outside part of the piping 10, and gas flow-in means for making a gas flow into the piping includes: a sending process for moving a cutting part to the other end side from one end side of the piping in a pipe axial direction, and removing a wall thickness of the piping between portions at which the cutting part moves to the other end side from one end side; and a return process for moving the cutting part to one end side from the other end side. A gas is made to flow into the piping by the gas flow-in means at a time except for a time at which the cutting part in at least the sending process out of the sending process and the return process cuts the piping.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a pipe cutting method for cutting a pipe, a pipe cutting device, and a method for controlling the pipe cutting device. [Background technology]

[0002] Patent Document 1 discloses a diameter expansion device equipped with cutting blades that expands the diameter of an existing pipe (buried plastic pipe) with a circular cross section. The diameter expansion device has an outer periphery that serves as a diameter expansion surface that expands the inner diameter of the existing pipe, and a plurality of cutting blades are arranged radially on the front side of the diameter expansion device, and the tip of a new pipe (replacement plastic pipe) is fixed to the rear of the diameter expansion device.

[0003] In the configuration described in Patent Document 1, a cutting blade is used to form an expansion notch along the pipe axis direction on the inner surface of the existing pipe, the inner diameter of the existing pipe is expanded by the expansion surface of the expansion device, and the new pipe following the expansion device is inserted into the existing pipe by widening the expansion notch and guiding the existing pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-184996 Summary of the Invention [Problem to be solved by the invention]

[0005] In indoor water supply pipes and the like, protective materials are sometimes provided to cover the outer diameter of the pipes in order to maintain the temperature of the fluid flowing inside and to protect the water supply pipes, etc. However, when the diameter of an existing pipe covered with a protective material is expanded by the method described in Patent Document 1, the pipe is cut in the axial direction, which is inconvenient as it can damage the protective material.

[0006] Therefore, an object of the present invention is to provide a pipe cutting method, a pipe cutting device, and a control method for the pipe cutting device that can process existing pipes that have protective material provided to cover the outer diameter of the pipe without any problems. [Means for solving the problem]

[0007] The pipe cutting method of the present invention is a pipe cutting method using a pipe cutting device including: a cutting unit that rotates an existing pipe, in which a protective material is provided to cover a radially outer side of the pipe, about a center in the pipe axial direction and abuts against the pipe in the pipe axial direction to cut a wall thickness of the pipe; a drive unit that applies a rotational force to the cutting unit; a connection unit configured to be connectable between the cutting unit and the drive unit so as to transmit the rotational force; and a gas inflow means for inflowing a gas into the pipe, the method including: a feeding step of moving the cutting unit from one end side to the other end side in the pipe axial direction of the pipe, and removing a wall thickness of the pipe during a portion of the movement of the cutting unit from the one end side to the other end side; and a return process in which the cutting portion, which was moved from one end side to the other end side of the pipe in the feed process, is moved from the other end side to the one end side, wherein a feed distance, which is the distance by which the cutting portion is moved from one end side to the other end side in the feed process, is longer than a return distance, which is the distance by which the cutting portion is moved from the other end side to the one end side in the return process, and a cutting distance, which is the distance by which the cutting portion cuts the pipe in the feed process, is set shorter than the return distance, and the gas inflow means is configured to flow into the interior of the pipe during the feed process and the return process, at least except for the time during which the cutting portion is cutting the pipe in the feed process.

[0008] According to this configuration, the cutting section cuts the wall thickness of the pipe by contacting it from the pipe axial direction, so that damage to the protective material can be suppressed, and since the gas inflow means flows into the inside of the pipe while the cutting section is not cutting the pipe, chips generated by cutting can be reliably blown away by the gas. Therefore, since damage to the protective material can be suppressed while cutting is prevented from being hindered by the accumulation of chips, the pipe can be processed without any inconvenience.

[0009] In addition, the cutting portion includes a blade portion that cuts the pipe, and an insertion guide portion that protrudes from the tip side of the blade portion, and the insertion guide portion is configured to be inserted into the inside of the pipe along the pipe axis direction and to guide the movement of the blade portion in the pipe axis direction, and the return distance in the return process can be set to be shorter than the protruding length of the insertion guide portion.

[0010] With this configuration, the insertion guide portion is maintained inserted into the portion of the piping that is not cut in the axial direction during the return process, so that the cut portion can be prevented from shifting radially relative to the piping even if the feed process and return process are repeatedly performed.

[0011] Further, a pipe cutting device of the present invention includes a cutting unit that rotates an existing pipe, in which a protective material is provided to cover a radially outer side of the pipe, about a center in a pipe axial direction and abuts against the pipe in the pipe axial direction to cut a wall thickness of the pipe, a drive unit that applies a rotational force to the cutting unit, a connection unit configured to be able to connect the cutting unit and the drive unit so as to transmit a rotational force, a moving unit that moves the cutting unit to one side and the other side in the pipe axial direction along the pipe axial direction of the pipe, a gas inflow unit that inflows gas into the pipe, and a control unit that controls the entire device, and the control unit moves the cutting unit from one end side to the other end side in the pipe axial direction of the pipe, a feed process for removing thickness of the pipe during the feed process, and a return process for moving the cutting portion, which has moved from one end side to the other end side of the pipe in the feed process, back to the one end side, wherein a feed distance, which is a distance by which the cutting portion is moved from one end side to the other end side in the feed process, is set to be longer than a return distance, which is a distance by which the cutting portion is moved from the other end side to the one end side in the return process, and a cutting distance, which is a distance by which the cutting portion cuts the pipe in the feed process, is set to be shorter than the return distance, and the gas inflow means is controlled to flow into the interior of the pipe during the feed process and the return process, except at least during the time when the cutting portion is cutting the pipe in the feed process.

[0012] According to this configuration, the cutting section cuts the wall thickness of the pipe by contacting it from the pipe axial direction, so that damage to the protective material can be suppressed, and the control section controls the gas inflow means to infuse gas into the inside of the pipe while the cutting section is not cutting the pipe, so that chips generated by cutting can be reliably blown away by the gas. Therefore, damage to the protective material can be suppressed while cutting interference caused by accumulation of chips can be suppressed, so that the pipe can be processed without any inconvenience.

[0013] Further, a control method for a pipe cutting device of the present invention is a control method for a pipe cutting device including: a cutting unit that rotates an existing pipe, in which a protective material is provided to cover a radially outer side of the pipe, about a center in a pipe axial direction and abuts against the pipe in the pipe axial direction to cut a wall thickness of the pipe; a drive unit that applies a rotational force to the cutting unit; a connection unit configured to be able to connect the cutting unit and the drive unit so as to transmit a rotational force; a moving unit that moves the cutting unit to one side and the other side in the pipe axial direction along the pipe axial direction of the pipe; and a gas inflow unit that inflows gas into the inside of the pipe, the control method including: moving the cutting unit from one end side to the other end side of the pipe axial direction, a feed process for removing thickness of the pipe during the feed process, and a return process for moving the cutting portion, which has moved from one end side to the other end side of the pipe in the feed process, back to the one end side, wherein a feed distance, which is a distance by which the cutting portion is moved from one end side to the other end side in the feed process, is set to be longer than a return distance, which is a distance by which the cutting portion is moved from the other end side to the one end side in the return process, and a cutting distance, which is a distance by which the cutting portion cuts the pipe in the feed process, is set to be shorter than the return distance, and the gas inflow means is controlled to flow into the interior of the pipe during the feed process and the return process, except at least during the time when the cutting portion is cutting the pipe in the feed process.

[0014] According to this configuration, the pipe cutting device cuts the pipe by contacting the pipe thickness from the pipe axial direction with the cutting part, so that damage to the protective material can be suppressed, and since the gas inflow means controls the gas to flow into the inside of the pipe while the cutting part is not cutting the pipe, chips generated by cutting can be reliably blown away by the gas. Therefore, damage to the protective material can be suppressed while cutting interference caused by accumulation of chips can be suppressed, so that the pipe can be processed without any inconvenience. Effect of the Invention

[0015] According to the present invention, it is possible to obtain a pipe cutting method, a pipe cutting device, and a control method for the pipe cutting device that can process existing pipes in which protective material is provided to cover the outer diameter of the pipe without any problems. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing an example of the arrangement of pipes in a building that are the subject of a pipe renewal method including a pipe cutting method according to one embodiment of the present invention. FIG. [Diagram 2] 2 is a diagram showing a main part of a pipe cutting device used in the pipe cutting method. FIG. [Diagram 3] (a) is a front view of the cutting edge, and (b) is a side view from the direction of travel. [Figure 4] FIG. 2 is a diagram showing an outline of the pipe cutting device. [Diagram 5] 1A is a diagram showing an inlet machining step of the pipe cutting method, in which (a) shows a preparation step, (b) shows a step of cutting the inlet, and (c) shows a step of moving a cutting part toward the inlet side. [Figure 6] 1A and 1B are diagrams illustrating a cutting cycle of the pipe cutting method, in which (a) shows the start, (b) shows the completion of the feed process, and (c) shows the completion of the return process. [Figure 7] 6A to 6C are diagrams showing timings at which the gas inlet means injects gas in the cutting cycle. [Figure 8]1A and 1B are diagrams illustrating an insertion step of the piping renewal method, in which (a) illustrates a preparation stage for insertion, and (b) illustrates a completion stage of the insertion step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A pipe renewal method including a pipe cutting method according to one embodiment of the present invention, a pipe cutting device 12 used in the pipe renewal method, and a method for controlling the pipe cutting device 12 will be described with reference to Figures 1 to 8. For convenience of explanation, the inlet 4 and the outlet 5 will be described with the inlet 4 being the side where the cutting part 13 is inserted in the axial direction of the existing pipe 8, and the outlet 5 being the opposite side. First, an overview of a hot water supply pipe 1 or a cold water supply pipe 2 that is generally used in a building will be described.

[0018] As shown in Fig. 1, generally, at least a middle portion of a hot water supply pipe 1 or a water supply pipe 2 indoors is covered in the pipe axis direction by a floor surface 3. The pipe axis direction is a direction along the axial center of the hot water supply pipe 1 or the water supply pipe 2. In addition, an inlet 4 to an outlet 5 in the pipe axis direction are exposed from the floor surface 3, and the inlet 4 which is the rear end of the hot water supply pipe 1 is connected to a water heater via, for example, a header member 6, and the outlet 5 which is the front end of the hot water supply pipe 1 is connected to, for example, a water faucet 7 in the bathroom. Note that the inlet 4 and the outlet 5 are not limited to being connected as described above, and for example, the inlet 4 may be attached to the water heater via a joint member.

[0019] Since the hot water supply pipe 1 and the water supply pipe 2 have the same configuration, the hot water supply pipe 1 will be described as being used also as the water supply pipe 2. The hot water supply pipe 1 is formed by inserting a flexible inner pipe (pipe 10) made of a polyethylene pipe, a cross-linked polyethylene pipe, an aluminum three-layer pipe, or the like, into a protective material 9 made of a tubular insulating material, for example, a foamed resin. In other words, the hot water supply pipe 1 (water supply pipe 2) is a flexible pipe 10 that can be bent. The hot water supply pipe 1 is also firmly fixed at a predetermined interval in the pipe axis direction to a slab or the like arranged below the floor surface 3 (not shown).

[0020] This embodiment relates to a pipe renewal method for renewing an existing hot water supply pipe 1 or cold water supply pipe 2 (existing pipe 8), in which the wall thickness of the pipe 10 is cut, and then a new pipe 11 is installed inside a protective material 9 along the pipe axis direction. Here, the new pipe 11 is installed for the hot water supply pipe 1 as the existing pipe 8 having the pipe 10 and the protective material 9 provided so as to cover the radially outer side of the pipe 10 (see FIG. 8).

[0021] The pipe axis direction is the direction along the axial direction of the hot water supply pipe 1, and the new pipe 11 is also inserted along the pipe axis direction of the hot water supply pipe 1. The new pipe 11 constitutes a new hot water supply pipe 1. Like the pipe 10, the new pipe 11 is formed from a polyethylene pipe, a cross-linked polyethylene pipe, a polybutene pipe, an aluminum three-layer pipe, or the like, and is a flexible pipe that can be bent in the axial direction. In this embodiment, the new pipe 11 has an outer diameter smaller than that of the pipe 10. Furthermore, the new pipe 11 has an outer diameter larger than the inner diameter of the pipe 10.

[0022] Prior to describing the piping renewal method of this embodiment, a pipe cutting device 12 used in the piping renewal method will be described.

[0023] As shown in Fig. 2, pipe cutting device 12 includes handle 16 that is detachable from the tip of drive unit 14, cutting unit 13 arranged on the tip side of handle 16, and connecting unit 15 that connects handle 16 and cutting unit 13. Also, as shown in Fig. 4, pipe cutting device 12 includes feed unit 17 configured to push cutting unit 13 and connecting unit 15 from the inlet 4 side, traction unit 18 configured to pull cutting unit 13 from the outlet 5 side, and gas inflow means 23 that flows gas into pipe 10. Furthermore, pipe cutting device 12 includes a control unit (not shown) that controls the entire device.

[0024] 2, a typical rotary power tool is used for the drive unit 14, and a handle 16 is connected to the tip of the main body, and the cutting part 13 is rotated so that the pipe axis direction becomes the center of rotation. In this embodiment, the drive unit 14 is disposed outside the existing pipe 8. However, the drive unit 14 may be disposed inside the existing pipe 8.

[0025] Handle 16 in pipe cutting device 12 is formed so as to be detachably connected to the tip shape of drive unit 14. Handle 16 is formed to have a length in the pipe axial direction that can withstand being gripped by drive unit 14 so as to extend along the pipe axial direction. Handle 16 is also configured so as to be able to transmit the rotational force of drive unit 14 to coupling unit 15.

[0026] The connecting portion 15 is a portion that connects the handle 16 and the cutting portion 13. The rear end of the connecting portion 15 is connected to the tip of the handle 16, and the tip is connected to the rear end of the cutting portion 13, thereby connecting the handle 16 and the tip. The connecting portion 15 can transmit the rotational force of the drive portion 14 transmitted via the handle 16 to the cutting portion 13. Furthermore, the connecting portion 15 has an attachment portion 151 at the tip to which the cutting portion 13 can be attached and detached. The connecting portion 15 of this embodiment is configured by connecting a plurality of rod-shaped shafts 19 that extend in the axial direction. Specifically, the shaft 19 has extension portions 191 at both ends in the axial direction. The extension portions 191 are configured to be connectable to other extension portions 191. That is, by connecting the extension part 191 of one shaft 19 to the extension part 191 of another shaft 19, the shafts 19 can be connected to each other, and the axial length of the connecting part 15 can be extended. The shaft 19 of this embodiment has a male thread at the tip and a female thread at the rear end (not shown). That is, the shaft 19 of this embodiment is configured so that the one shaft 19 can be connected to the other shaft 19 by screwing the male thread at the tip and the female thread at the rear end together. The shaft 19 also has flexibility in the axial direction. That is, the connecting part 15 is configured so that it can be bent along the axial direction of the pipe 10 when inserted into the pipe 10.

[0027] The cutting portion 13 is a portion that comes into contact with the pipe 10 in the pipe axial direction to cut the wall thickness of the pipe 10. Specifically, the cutting portion 13 includes a blade portion 130 that cuts the pipe 10, and an insertion guide portion 22 provided on the tip side of the blade portion 130. Moreover, the blade portion 130 and the insertion guide portion 22 can be attached to the tip of the connecting portion 15. In this embodiment, the blade portion 130 and the insertion guide portion 22 are configured as separate bodies.

[0028] 3, the blade portion 130 is a part (cutting tool) that rotates around the pipe axis of the pipe 10 (in a rotation direction R) and cuts the entire thickness of the pipe 10 by contacting the pipe end surface (cutting end surface 10a) of the pipe 10. Furthermore, the blade portion 130 can rotate in the rotation direction R by receiving a rotation force transmitted to the connecting portion 15. In this embodiment, the blade portion 130 includes a base end portion 135 and a plurality of cutting blade portions 136.

[0029] The base end 135 is formed in a disk shape, and is provided at the center of the base end 135 with a mounting recess 135a that can be connected to the attachment portion 151 of the connecting portion 15. The mounting recess 135a has a female thread 135b that can be screwed into the attachment portion 151 provided at the tip of the connecting portion 15. The base end 135 is also configured so that it can be released from its connection with the attachment portion 151. By releasing the screw engagement between the mounting recess 135a and the attachment portion 151, the connection between the base end 135 and the connecting portion 15 is released.

[0030] The cutting blade 136 will be described. The cutting blade 136 is arranged in the circumferential direction of the base end 135 from the outer periphery of the base end 135 in the direction of travel, and a plurality of cutting blades 136 are arranged at predetermined angles in the circumferential direction of the base end 135. For example, the cutting blades 136 are arranged at 90° intervals in the circumferential direction. In this case, the outer diameter of the outer periphery of the cutting blade 136 radially facing the base end 135 is set to be larger than the outer diameter of the pipe 10 and smaller than the inner diameter of the protective material 9.

[0031] Each cutting blade portion 136 has a leading side surface (rake surface) 137A, a trailing side surface 137B, an outer peripheral surface 137C, an inner peripheral surface 137D, a tip surface (flank surface) 137E, and a trailing end surface 137F. The leading side surface 137A has a surface along the central axis direction and the radial direction, and a cutting edge 139 at a tip edge in the central axis direction that abuts against the cutting end surface 10a of the pipe 10 to cut the pipe 10. The trailing side surface 137B is disposed parallel to the leading side surface 137A. That is, the trailing side surface 137B is a surface along a direction perpendicular to the leading side surface 137A of the trailing cutting blade portion 136 in the rotational direction R. The trailing side surface 137B is also a surface that has an angle of 90° or more in the rotational direction R with respect to the trailing leading side surface 137A. The cutting blades 136 are arranged at 90° intervals in the circumferential direction, so that gaps 138 are formed between the cutting blades 136. The outer peripheral surface 137C is a surface that forms a radial outer periphery along the circumferential direction of rotation and continues the leading side surface 137A and the trailing side surface 137B at the outer periphery. This outer peripheral surface 137C is a cylindrical surface. The inner peripheral surface 137D is formed radially inward of the outer peripheral surface 137C and parallel to the outer peripheral surface 137C. The tip surface 137E is a surface that is inclined backward from the tip region of the outer peripheral surface 137C toward the center of the pipe 10. In other words, the outer radial edge is inclined so as to be located closer to the tip side in the pipe axial direction than the inner edge. The continuous surface between the leading side surface 137A and the tip surface 137E is the cutting edge 139, and the tip surface 137E is formed to be inclined toward the rear end as it approaches the rear side in the rotation direction R so that the cutting edge 139 becomes the tip in the tube axial direction. The rear end surface 137F is formed at the rear ends of the leading side surface 137A and the trailing side surface 137B, and is a surface that continues to the rear end of the base end portion 135 that is formed in a disk shape.

[0032] In this embodiment, a tip ridge 141 is formed at the connecting portion between the outer peripheral surface 137C and the tip surface 137E, i.e., the connecting portion between the tip edge portion of the outer peripheral surface 137C in the tube axis direction and the radial outer edge portion of the tip surface 137E. The tip ridge 141 chamfers the cutting edge side portion. The tip ridge 141 (chamfer) is a part of the cutting blade portion 136 on the side in the rotation direction R.

[0033] In this embodiment, a leading ridge portion (edge ​​corner portion) 142 is formed at a connecting portion between the leading side surface 137A and the outer peripheral surface 137C, i.e., a radial outer edge portion of the leading side surface 137A and a rotational edge portion of the outer peripheral surface 137C. The leading side portion is chamfered by the leading ridge portion 142.

[0034] In this embodiment, a rear end ridge 143 is formed at a continuous portion between the outer circumferential surface 137C and the rear end surface 137F, that is, at a continuous portion which is a rear end edge portion in the tube axis direction of the outer circumferential surface 137C and a radial outer edge portion of the rear end surface 137F. The rear end ridge 143 chamfers the rear end edge portion in the tube axis direction of the cutting blade portion 136.

[0035] As shown in FIG. 2, the insertion guide portion 22 is a portion provided so as to protrude from the tip side of the blade portion 130. The insertion guide portion 22 is a portion having an outer diameter smaller than the outer diameter of the blade portion 130. The insertion guide portion 22 is a portion having a tapered tip. Specifically, the insertion guide portion 22 includes a columnar guide base portion 221 provided at the tip of the blade portion 130 and a tapered guide tip portion 222 provided at the tip of the guide base portion 221. The insertion guide portion 22 is inserted into the inside of the pipe 10 along the pipe axis direction and guides the movement of the blade portion 130 in the pipe axis direction. The insertion guide portion 22 of this embodiment is configured to guide both the movement of the blade portion 130 toward the pipe axis inlet 4 side (the direction of insertion into the pipe 10) and the movement of the blade portion 130 toward the pipe axis outlet 5 side (the direction of removal from the pipe 10). Specifically, the insertion guide portion 22 abuts against the inner peripheral surface of the pipe 10 to prevent the blade portion 130 from shifting radially relative to the pipe 10, thereby guiding the movement of the blade portion 130 in the pipe axial direction.

[0036] The guide base 221 is a columnar body that can be attached to the tip of the blade section 130. The guide base 221 of this embodiment is cylindrical. The guide base 221 has an outer diameter smaller than that of the blade section 130. The guide base 221 has an outer diameter smaller than the inner diameter of the pipe 10 before cutting. The guide base 221 of this embodiment can be connected to the tip of the connecting section 15. That is, the guide base 221 can be attached to the mounting section 151 of the connecting section 15. Specifically, the guide base 221 can be attached to the mounting section 151 in a state in which the blade section 130 is attached, at a position on the tip side of the blade section 130. The guide base 221 of this embodiment is provided so as to protrude from the blade section 130 to the tip side.

[0037] The guide tip portion 222 is a tapered portion provided on the tip side of the guide base portion 221. Also, a rope body connection hole 222a capable of connecting the rope body 20 described later is formed in the guide tip portion 222. That is, the guide tip portion 222 is a portion that connects the rope body 20 to the guide base portion 221 and the connecting portion 15 connected to the guide base portion 221, and is configured such that the outer diameter of the rear end portion is approximately the same as the outer diameter of the guide base portion 221 and the outer diameter becomes smaller toward the tip side.

[0038] As shown in FIG. 4, the feed section 17 includes a feeder 171 capable of pushing the connecting section 15 (specifically, the shaft 19) from the rear end side toward the tip end side, a tubular inlet side auxiliary pipe 173 that connects the feeder 171 and the inlet 4 of the existing piping 8, and an auxiliary pipe mounting jig 174 that is a jig that connects the inlet side auxiliary pipe 173 to the inlet 4 of the existing piping 8.

[0039] The feeder 171 is a tool that can move the elongated body along the axial direction of the elongated body. The feeder 171 of this embodiment is circular and includes a pair of feeder bodies 172 arranged to sandwich the connecting portion 15 from the sides, and the feeder bodies 172 are configured to rotate in opposite directions about an axis in the vertical direction. With this configuration, the feeder 171 can move the connecting portion 15 sandwiched between the pair of feeder bodies 172 along the axial direction of the connecting portion 15 by rotating the pair of feeder bodies 172. The feeder 171 of this embodiment can operate to move the connecting portion 15 to one side in the axial direction or to the other side.

[0040] The inlet side auxiliary pipe 173 is a pipe that connects the tip of the feeder 171 and the inlet 4 of the piping 10. The inlet side auxiliary pipe 173 is a pipe into which the cutting portion 13 and the connecting portion 15 can be inserted. Specifically, the inlet side auxiliary pipe 173 is a pipe having an inner diameter larger than the inner diameter of the piping 10. The inner diameter of the inlet side auxiliary pipe 173 is also larger than the outer diameter of the connecting portion 15. The inlet side auxiliary pipe 173 is a pipe that is flexible in the axial direction. The inlet side auxiliary pipe 173 of this embodiment is attached to the inlet 4 of the piping 10 via a tubular auxiliary pipe attachment jig 174 that extends in front of the opening of the inlet 4 of the piping 10.

[0041] The auxiliary pipe mounting jig 174 is a pipe that does not have flexibility and extends linearly. Furthermore, at least a part of the inlet side auxiliary pipe 173 and the auxiliary pipe mounting jig 174 is configured so that the internal state can be confirmed. In this embodiment, a part of the auxiliary pipe mounting jig 174 is provided with a window portion 175 through which the internal state can be confirmed. In this way, by providing a part of the auxiliary pipe mounting jig 174 with the window portion 175, it is possible to confirm the state of the connecting portion 15 and the cutting portion 13 immediately before being inserted into the piping 10, the discharge state of the chips, and the like. Furthermore, the auxiliary pipe mounting jig 174 includes an inlet connecting portion 176 that is connected to the inlet 4 of the existing piping 8, an auxiliary pipe connecting portion 177 that is connected to the tip portion of the inlet side auxiliary pipe 173, and a chip discharge portion 178 that is provided in the middle of the inlet connecting portion 176 and the auxiliary pipe connecting portion 177 and allows gas and chips to flow out to the outside. The chip discharge portion 178 is provided between the window portion 175 and the auxiliary pipe connection portion 177, and is a portion having holes formed therein through which gas and chips can flow out to the outside. The chip discharge portion 178 is also a portion to which the dust collector 25, which will be described later, can be connected.

[0042] The traction unit 18 is a part that traction the cutting unit 13 from the outlet 5 side. As shown in Fig. 4 and Fig. 5, the traction unit 18 includes a rope body 20 that is connected to the cutting unit 13 and extends from the cutting unit 13 toward the tip side (toward the outlet 5 side in the pipe axial direction), an intermediate guide unit 21 that is provided in the middle of the extension direction of the rope body 20, a winding machine 181 that inserts the rope body 20 and the intermediate guide unit 21 into the piping 10 from the outlet 5 side or pulls them from the outlet 5 side, and an outlet side auxiliary pipe 182 that connects the winding machine 181 and the outlet 5 of the existing piping 8.

[0043] The rope 20 is a rope having an outer diameter smaller than the inner diameter of the pipe 10. The rope is also capable of withstanding the tensile force that pulls the cutting section 13. The rope 20 of this embodiment is made of a metal wire. The rope 20 includes a tip-side rope 20A located on the tip side of the intermediate guide section 21 (the opposite side to the cutting section 13 in the axial direction of the pipe 10), and a rear-side rope 20B located on the rear-side of the intermediate guide section 21 (the cutting section 13 side).

[0044] The intermediate guide portion 21 is a portion provided in the middle of the extension direction of the rope body 20. The intermediate guide portion 21 is a portion having an outer diameter larger than the outer diameter of the rope body 20. Specifically, the intermediate guide portion 21 is a tube or column whose outer diameter is approximately the same as the inner diameter of the pipe 10. The intermediate guide portion 21 in this embodiment is a cylindrical body. Note that approximately the same as the inner diameter of the pipe 10 does not mean a diameter exactly the same as the inner diameter of the pipe 10, but means a diameter small enough to allow movement within the pipe 10 relative to the inner diameter of the pipe 10. That is, the intermediate guide portion 21 is a tube or column whose outer diameter is small enough to prevent clogging or getting caught when inserted into the pipe 10, relative to the inner diameter of the pipe 10. The intermediate guide portion 21 in this embodiment is disposed in the middle of the extension direction of the rope body 20 by connecting the rope body 20 to one end and the other end in the axial direction. Moreover, the intermediate guide portion 21 is configured such that one end portion in the axial direction and the other end portion in the axial direction rotate relatively around the center in the axial direction. Specifically, the part of the intermediate guide portion 21 to which the rope body 20 is connected at one end portion and the part to which the rope body 20 is connected at the other end portion are configured to rotate relatively around the center in the axial direction. The intermediate guide portion 21 of this embodiment is provided with a bearing inside (not shown). Such an intermediate guide portion 21 is a rotation insulating portion configured so that the rotation of the cutting portion 13 is not transmitted to the rope body 20 (tip side rope body 20A) arranged on the tip side of the intermediate guide portion 21. That is, in the rope body 20, the rotation appears on the surface only in the part on the rear end side (rear end side rope body 20B) from the intermediate guide portion 21.

[0045] The winding machine 181 is a tool that can move the elongated body along the extension direction of the elongated body. The winding machine 181 of this embodiment is circular and includes a pair of winding main bodies 183 arranged to sandwich the rope body 20 from the sides, and the winding main bodies 183 are configured to rotate in opposite directions about an axis in the vertical direction. With this configuration, the winding machine 181 can move the rope body 20 sandwiched between the pair of winding main bodies 183 along the axial direction of the rope body 20 by rotating the pair of winding main bodies 183. Note that the winding machine 181 of this embodiment can operate to move the rope body 20 to one side in the axial direction or to the other side. Furthermore, the rope body 20 is wound around one of the pair of winding main bodies 183. Specifically, the rope 20 is wound around one of the winding machine 181 bodies, and when the rope 20 moves toward the entrance 4 side, it leaves the winding machine 181 body and is inserted into the piping 10, and when the rope 20 is pulled to move toward the exit 5 side, the rope 20 is wound around the winding machine 181 body.

[0046] The winder 181 and the feeder 171 are configured to operate synchronously. Specifically, the winder 181 and the feeder 171 are controlled by the control unit to operate synchronously. In this embodiment, the control unit controls the winder 181 to wind the rope body 20 by the length of the fed connecting part 15 when the feeder 171 has fed the connecting part 15 into the pipe 10 (moved toward the outlet 5), and controls the winder 181 to feed the rope body 20 into the pipe 10 by the length moved in the extracting direction when the feeder 171 has moved the connecting part 15 in the direction of extracting it from the inside of the pipe 10 (to the inlet 4). In this embodiment, the winder 181 and the feeder 171 are configured to receive power from the same power supply device P.

[0047] As shown in FIG. 4, the gas inflow means 23 includes a compressor 24 that causes gas to flow into the piping 10 from the outlet 5 side, and a dust collector 25 that sucks in the gas and chips flowing with the gas at the inlet 4 side of the existing piping 8. That is, the gas inflow means 23 is a means for causing gas to flow into the piping 10 from the outlet 5 side of the piping 10. In this embodiment, the gas that the gas inflow means 23 causes to flow into the piping 10 is air. Note that the gas that the gas inflow means 23 causes to flow into the piping 10 is not limited to air, and for example, an inert gas can also be caused to flow. In addition, the gas inflow means 23 of this embodiment causes gas to flow into the piping 10 intermittently. The gas inflow means 23 causes gas to flow from the outlet 5 side toward the inlet 4 side, thereby generating an airflow F in the piping 10. The airflow F in this embodiment is a gas flow that flows from the compressor 24 through the outlet auxiliary pipe 182, the existing piping 8 (piping 10 and protective material 9), and the inlet auxiliary pipe 173 toward the dust collector 25.

[0048] The compressor 24 is configured to compress gas and cause the compressed gas to flow into the pipe 10. In this embodiment, the compressor 24 compresses air and causes the compressed air to flow into the pipe 10. The compressor 24 is also controlled to cause the gas to flow into the pipe 10 at least at a predetermined timing. Specifically, the compressor 24 is controlled by the control unit and causes the gas to flow into the pipe 10 at a predetermined timing in accordance with the operations of the winder 181 and the feeder 171. In this embodiment, the compressor 24 is configured to cause the gas to flow intermittently into the pipe 10. Furthermore, the compressor 24 includes a compression main body 241 that compresses the gas and an inlet pipe 242 that is a pipe that sends the compressed gas into the pipe 10, and the inlet pipe 242 is connected to the outlet 5 side of the outlet side auxiliary pipe 182. That is, in this embodiment, the compressor 24 causes the gas to flow into the pipe 10 via the outlet side auxiliary pipe 182.

[0049] The dust collector 25 is a part that collects chips on the inlet 4 side of the piping 10. That is, the dust collector 25 collects chips that flow from the inside of the piping 10 to the inlet 4 side together with the gas that is caused to flow into the piping 10 by the compressor 24. The dust collector 25 of this embodiment includes an intake section 251 that draws in gas, a tubular dust collection pipe 252 that can connect the intake section 251 and the chip discharge section 178 of the auxiliary pipe mounting jig 174, and a filter section 253 that can filter the flowing gas and remove the chips. In this embodiment, the filter section 253 is configured to remove the chips that flow together with the gas drawn by the dust collector 25.

[0050] A method for cutting pipe 10 using pipe cutting device 12 configured as above will be described with reference to Fig. 5 to Fig. 7. In Fig. 5 and Fig. 6, in order to explain the pipe cutting method in a schematic manner, feeding machine 171 arranged on the inlet 4 side, a curved portion of hot water supply pipe 1, etc. are not shown.

[0051] The piping renewal method according to this embodiment will be specifically described as follows: (1) a pipe cutting process in which a pipe 10 is cut from an inlet 4 to an outlet 5 in the pipe axial direction by a cutting part 13 to reduce a wall thickness of the pipe 10; (2) an insertion process in which the new pipe 11 is inserted into the existing pipe 8, the wall of which has been cut and the inside diameter of which has been enlarged, by pulling the new pipe 11 from the outlet 5 using an insertion tool (in this case, a pipe insertion tool 26 shown in FIG. 9 ); In this construction method, the protective material 9, the pipe 10, and the new pipe 11 have a circular cross section.

[0052] The above-mentioned pipe cutting process (1) will be described in more detail. The pipe cutting process (1) is performed by applying a pipe cutting method. Specifically, the pipe cutting process includes, in the order of execution, a removal process as a preparation stage for cutting, and a pipe cutting execution process for cutting the wall thickness of the pipe 10.

[0053] The removal process is a process of making, for one hot water supply pipe 1, a region of the hot water supply pipe 1 exposed to the floor surface 3 into a free end, as shown by the two-dot chain line in FIG.

[0054] The method of performing the removal process involves removing one end (the end on the inlet 4 side) of the hot water supply pipe 1 from the header member 6 to form the inlet 4, removing the other end of the hot water supply pipe 1 from the faucet 7 to form the outlet 5, and forming a single protective material 9 including straight and curved regions (for example, the curved portion in FIG. 1) and the existing pipe 8, with the inlet 4 and outlet 5 being free ends. This removal process may also include a process of orienting the free end in a convenient (easy to work with) direction in a subsequent process.

[0055] In the pipe cutting execution process, as shown in FIG. 5, first, an inlet processing process is performed in which cutting is performed a predetermined distance from the inlet 4 of the pipe 10, and after completion of the inlet processing process, a cutting cycle process is performed in which the pipe 10 is sequentially cut.

[0056] As shown in FIG. 5(a), in the inlet processing step, first, the rope body 20 and the intermediate guide portion 21 of the towing portion 18, and the insertion guide portion 22 whose tip portion is connected to the rope body 20, are inserted from the outlet 5 of the piping 10 toward the inlet 4. Specifically, a rope-like call line is inserted into the piping 10 in advance, and the rope body 20 (tip side rope body 20A) is pulled and inserted from the outlet 5 of the existing piping 8 to the inlet 4 by the call line. After the rope body 20 is exposed from the inlet 4, the intermediate guide portion 21 (first intermediate guide portion 21A), the rear end side rope body 20B, and the insertion guide portion 22 are connected to the rear end portion of the rope body 20 (tip side rope body 20A), so that the towing portion 18 is inserted from the outlet 5 side to the inlet 4 side of the piping 10, and the first preparation step is completed. In the first preparation step, the case where only the rope body 20 is inserted into the piping 10 using the call wire as described above, and then the intermediate guide portion 21 and the insertion guide portion 22 are connected on the inlet 4 side has been described, but the present invention is not limited to this case, and the rope body 20 to which the insertion guide portion 22 and the intermediate guide portion 21 are attached may be pulled by the call wire and inserted into the piping 10. In addition, when inserting the pulling portion 18, the pulling portion 18 may be inserted into the piping 10 by pushing it in from the outlet 5 side, not limited to the case where the pulling portion 18 is inserted using the call wire.

[0057] As shown in FIG. 5(b), the cutting section 13 and the connecting section 15 are connected to the rear end of the cord body 20 inserted from the outlet 5 side to the inlet 4 side, and the blade section 130 is brought into contact with the pipe end on the inlet 4 side of the piping 10 and moved toward the outlet 5 side to start cutting. Specifically, the blade section 130 of the cutting section 13 is brought into contact with the pipe end on the inlet 4 side of the piping 10, and the insertion guide section 22 is inserted into the piping 10. The driving section 14 is rotated, and the cutting section 13 (blade section 130) is rotated in the rotation direction R by the rotating force of the driving section 14, and the blade section 130 cuts the wall thickness of the piping 10. In this embodiment, the cutting section 13 is pulled by the pulling section 18 from the outlet 5 side and pushed by the feeding section 17 from the inlet 4 side, so that it moves from the inlet 4 side to the outlet 5 side. In this embodiment, cutting part 13 moves from the inlet 4 side to the outlet 5 side by being pushed mainly from the inlet 4 side by feeding part 17, and is secondarily pulled toward the outlet 5 side by pulling part 18. In the inlet processing step of this embodiment, cutting part 13 is moved a predetermined distance (feed distance L1) from the inlet 4 of pipe 10. That is, in the inlet processing step of this embodiment, the wall thickness of pipe 10 is cut by a predetermined distance (feed distance L1) from the inlet 4 of pipe 10.

[0058] As shown in FIG. 5(c), after cutting the pipe 10 by a predetermined distance (feed distance L1), the cutting part 13 moves toward the inlet 4 by a predetermined distance (return distance L2). That is, after cutting the pipe 10 by a predetermined distance (feed distance L1) in the inlet processing step, the cutting part 13 moves to a position moved toward the inlet 4 by a predetermined distance (return distance L2) from the cut end face 10a formed by cutting. Here, in the inlet processing step, the distance (return distance L2) by which the cutting part 13 moves toward the inlet 4 is shorter than the distance (feed distance L1) by which the cutting part 13 cuts the pipe 10 in the inlet processing step. Furthermore, in the inlet processing step, the distance (return distance L2) by which the cutting part 13 moves toward the inlet 4 is shorter than the protruding length from the blade part 130 of the insertion guide part 22. That is, when the cutting part 13 moves toward the inlet 4 by a predetermined distance (return distance L2), the insertion guide part 22 is in a state in which a part of the tip part is inserted into the pipe 10. In this embodiment, the cutting part 13 is pulled by the connecting part 15 from the entrance 4 side, thereby moving from the exit 5 side to the entrance 4 side. Specifically, the feeder 171 moves the connecting part 15 to the entrance 4 side, thereby pulling the cutting part 13 connected to the connecting part 15 to the entrance 4 side. In this embodiment, the rope 20 moves from the exit 5 side to the entrance 4 side as the cutting part 13 moves to the entrance 4 side. In this embodiment, the drive part 14 supplies a rotational force to the cutting part 13 even while the cutting part 13 moves to the entrance 4 side. That is, the cutting part 13 in this embodiment is configured to rotate about the tube axis even while it is not in contact with the cutting end face 10a.

[0059] In addition, the gas inflow means 23 flows gas into the pipe 10 at a predetermined timing during the inlet processing step. Specifically, the gas inflow means 23 flows gas into the pipe 10 while the cutting part 13 is moving toward the outlet 5 during the inlet processing step and cutting the pipe 10. In addition, the gas inflow means 23 flows gas into the pipe 10 at least while the cutting part 13 is moving toward the inlet 4 during the inlet processing step. That is, the gas inflow means 23 flows gas into the pipe 10 at least while the cutting part 13 is away from the cut end surface 10a. Furthermore, in this embodiment, the gas inflow means 23 flows gas into the pipe 10 at least during the inlet processing step, including the timing when the cutting part 13 switches from moving toward the outlet 5 side to moving toward the inlet 4 side. Furthermore, in this embodiment, the compressor 24 flows gas into the pipe 10 from the outlet 5 side of the pipe 10, thereby flowing gas into the pipe 10.

[0060] After the inlet machining process is completed, a cutting cycle process is performed. The cutting cycle process is a process in which a cutting cycle, in which a feed process and a return process described below are one cycle, is repeatedly performed. In this embodiment, the cutting cycle is repeatedly performed until the entire length of the pipe 10 is cut by the cutting section 13.

[0061] As shown in Fig. 6(a), the cutting cycle starts when the inlet machining step is completed and the cutting part 13 is a predetermined distance (return distance L2) away from the cutting end face 10a. The cutting cycle includes a feed step shown in Fig. 6(b) and a return step shown in Fig. 6(c) in the order shown.

[0062] In the feeding step, as shown in FIG. 6(b), from a state where the cutting part 13 is separated from the cutting end surface 10a by the return distance L2, the cutting part 13 is fed toward the outlet 5 by a feed distance L1 longer than the return distance L2, and cuts the pipe 10 by a length of a cutting distance L3 which is the difference between the return distance L2 and the feed distance L1. Specifically, the blade part 130 of the cutting part 13 is brought into contact with the pipe end on the inlet 4 side of the pipe 10, and the insertion guide part 22 is inserted into the pipe 10. The driving part 14 is rotated, and the cutting part 13 (blade part 130) is rotated in the rotation direction R by the rotation force of the driving part 14, and the blade part 130 cuts the wall thickness of the pipe 10. In this embodiment, the cutting part 13 is pulled from the outlet 5 side by the pulling part 18 and pushed from the inlet 4 side by the feeding part 17, so that the cutting part 13 moves from the inlet 4 side to the outlet 5 side. In this embodiment, the cutting part 13 is moved from the inlet 4 side to the outlet 5 side by being pushed mainly from the inlet 4 side by the feed part 17, and is secondarily pulled to the outlet 5 side by the towing part 18. As shown in Fig. 7, the feed process in this embodiment is performed for 7 seconds, and during the last 2 seconds of the feed process, the blade part 130 abuts against the cutting end face 10a and the cutting part 13 cuts the pipe 10. That is, during the feed process in this embodiment, the cutting part 13 moves toward the outlet 5 side by a feed distance L1 over 7 seconds, the blade part 130 does not abut against the cutting end face 10a during the first 5 seconds, and during the last 2 seconds, the blade part 130 abuts against the cutting end face 10a and cuts the distribution pipe 10 by a cutting distance L3.

[0063] In the return process, as shown in FIG. 6(c), the cutting part 13 that has completed the feed process (moved toward the outlet 5 by the feed distance L1) is moved toward the inlet 4 by a return distance L2. That is, in the return process, the cutting part 13 (blade part 130) that is in contact with the cutting end face 10a is moved toward the inlet 4, the blade part 130 is separated from the cutting end face 10a, and a space is formed between the cutting part 13 and the cutting end face 10a. In this embodiment, the distance (return distance L2) by which the cutting part 13 moves toward the inlet 4 in the return process is shorter than the protruding length of the insertion guide part 22 from the blade part 130. That is, when the cutting part 13 moves toward the inlet 4 by the return distance L2, the insertion guide part 22 is in a state in which a part of the tip part is inserted (remains) in the pipe 10. In addition, in this embodiment, the cutting part 13 moves from the outlet 5 side to the inlet 4 side by being pulled by the connecting part 15 from the inlet 4 side. Specifically, the feeder 171 moves the connecting portion 15 toward the entrance 4, thereby pulling the cutting portion 13 connected to the connecting portion 15 toward the entrance 4. In this embodiment, the rope 20 moves from the exit 5 side to the entrance 4 side as the cutting portion 13 moves toward the entrance 4. In this embodiment, the drive portion 14 supplies a rotational force to the cutting portion 13 even while the cutting portion 13 moves toward the entrance 4. That is, the cutting portion 13 in this embodiment is configured to rotate about the tube axis even while not in contact with the cutting end surface 10a. Furthermore, in this embodiment, the return process is performed for 5 seconds immediately after the feed process is completed. That is, in the return process of this embodiment, the cutting portion 13 moves toward the entrance 4 by a return distance L2 over 5 seconds.

[0064] In the cutting cycle, the feed distance L1, which is the distance by which the cutting part 13 moves to the outlet 5 side in the feed process, is longer than the distance by which the cutting part 13 moves to the inlet 4 side in the return process. In addition, in the feed process, the cutting part 13 cuts the distribution pipe 10 by a cutting distance L3, which is the difference between the return distance L2 and the feed distance L1. In this embodiment, the cutting distance L3 is shorter than the return distance L2. That is, in the cutting cycle of this embodiment, the distance by which the cutting part 13 returns to the inlet 4 side in the return process is longer than the distance by which the cutting part 13 cuts the pipe 10 in the feed process. Furthermore, in this embodiment, the return distance L2 is shorter than the protruding length from the blade part 130 of the insertion guide part 22. That is, when the blade part 130 abuts against the cutting end surface 10a, the insertion guide part 22 is inserted into the distribution pipe 10 by a length equal to or greater than the return distance L2.

[0065] The gas inlet means 23 causes gas to flow into the pipe 10 at a predetermined timing in the feed step and the return step. As shown in FIG. 7, the gas inlet means 23 causes gas to flow into the pipe 10 at least at the timing when the feed step is started (first inlet time T1). The gas inlet means 23 also causes gas to flow into the pipe 10 at least at the timing immediately before the blade portion 130 abuts against the cutting end surface 10a in the feed step (second inlet time T2). The gas inlet means 23 also causes gas to flow into the pipe 10 at least at the timing when the blade portion 130 abuts against the cutting end surface 10a and cuts the pipe 10 (third inlet time T3). The gas inlet means 23 also causes gas to flow into the pipe 10 at least during the return step (fourth inlet time T4). In addition, in this embodiment, the drive unit 14 supplies a rotation force to the blade portion 130 while the gas inlet means 23 causes gas to flow into the pipe 10. In this embodiment, the drive unit 14 supplies a rotational force to the cutting unit 13 throughout the duration of the cutting cycle.

[0066] Specifically, the gas inlet means 23 causes gas to flow into the pipe 10 at least during the feeding process except when the cutting portion 13 is cutting the pipe 10 (first inlet time T1, second inlet time T2, fourth inlet time T4). In other words, the gas inlet means 23 causes gas to flow into the pipe 10 while the blade portion 130 is separated from the cutting end surface 10a and a space is formed between the blade portion 130 and the cutting end surface 10a. In this embodiment, the gas inlet means 23 causes gas to flow into the pipe 10 at least at the timing when the blade portion 130 is separated from the cutting end surface 10a by the cutting distance L3 or more (first inlet time T1, fourth inlet time T4). The inflow of gas at each timing will be described below.

[0067] The first inflow time T1 is the timing at which the feed process starts. Therefore, at the first inflow time T1, the gas can be made to flow into the pipe 10 at the timing when the blade portion 130 is away from the cutting end face 10a by the return distance L2. Also, at the first inflow time T1, the blade portion 130 is located away from the cutting end face 10a by the return distance L2, which is longer than the cutting distance L3, so that the blade portion 130 is located closer to the inlet 4 than the range where the pipe 10 was cut in the previous cutting. Therefore, the chips generated by cutting can be reliably blown away by the gas.

[0068] The second inflow time T2 is a timing immediately before the blade portion 130 comes into contact with the cutting end surface 10a. Therefore, at the second inflow time T2, the gas can be made to flow into the pipe 10 at a timing when the blade portion 130 comes into contact with or is located close to the cutting end surface 10a. By making the gas flow in from the outlet 5 side at such a timing, the gas that has passed through the pipe 10 can come into contact with the cutting portion 13 with almost the same pressure. Therefore, the pressure of the flowing in gas makes it easier to blow away chips attached to the blade portion 130, so that the occurrence of poor cutting due to chips can be suppressed.

[0069] The third inflow time T3 is the timing when the blade portion 130 abuts against the cutting end surface 10a and cuts the pipe 10. The blade portion 130 abuts against the cutting end surface 10a while rotating during cutting, so frictional heat may be generated. Therefore, by injecting gas into the pipe 10 at the third inflow time T3, the frictional heat can be cooled by the gas, and the occurrence of cutting defects due to frictional heat (for example, the pipe 10 melted by frictional heat adheres to the blade portion 130) can be suppressed. In particular, as shown in FIG. 7, in this embodiment, at the third inflow time, the gas is injected into the pipe 10 at the timing when the blade portion 130 abuts against the cutting end surface 10a in one feed process and cutting of the pipe 10 is completed, so that the blade portion 130 and the pipe 10 can be appropriately cooled at the timing when the pipe 10 and the cutting portion 13 are likely to be heated by frictional heat.

[0070] The fourth inflow time T4 is a timing in the middle of the return process. Therefore, since the blade portion 130 has moved toward the inlet 4 side at the fourth inflow time T4, when gas is introduced from the outlet 5 side of the piping 10, the force with which the gas and the chips blown by the gas strike the blade portion 130 is smaller than when they strike during the feed process. Therefore, the chips blown by the gas strike the blade portion 130 strongly, and the chips stick to the blade portion 130, which can prevent poor cutting.

[0071] The above cutting cycle is repeated until a predetermined length (for example, the entire length of the pipe 10) is cut by the cutting section 13, and the pipe cutting process is completed.

[0072] After the (1) pipe wall thickness removal process is completed, the process proceeds to (2) the insertion process. In the insertion process, the new pipe 11 is inserted into the existing pipe 8 whose inner diameter has been enlarged. In this embodiment, a case where the new pipe 11 having an outer diameter smaller than that of the existing pipe 8 is inserted will be described. Also, in this embodiment, a case where the new pipe 11 is inserted into the existing pipe 8 using a rope body 20 and a pipe insertion tool 26 capable of fixing an end of the new pipe 11 will be described.

[0073] As shown in Figure 8, in the insertion process, the pipe insertion tool 26 attached to the rear end of the rope body 20 is attached to the tip end of the new pipe 11, and the rope body 20 is pulled to pull the new pipe 11 from the inlet 4 side to the outlet 5 side, and the new pipe 11 is inserted inside the existing pipe 8.

[0074] 8(a), in the insertion step, first, the rope body 20 and the pipe insertion tool 26 attached to the rear end of the rope body 20 are inserted from the outlet 5 side of the existing pipe 8 until they are exposed at the inlet 4 side. After the pipe insertion tool 26 is exposed at the inlet 4 side, the tip of the new pipe 11 is fixed to the pipe insertion tool 26. Note that as the pipe insertion tool 26, various pipe insertion tools 26 that can fix the tip of the new pipe 11 and connect the new pipe 11 and the rope body 20 can be used.

[0075] As shown in Fig. 8(b), after the tip of the new pipe 11 is fixed to the pipe insertion tool 26, the rope 20 is pulled from the exit 5 by a winch W or the like, and the tip of the new pipe 11 is moved from the entrance 4 to the exit 5. When the tip of the new pipe 11 is exposed from the exit 5, the insertion process is completed. Note that the rope 20 may be pulled not only by the winch W, but also by a winding machine 181.

[0076] With the above steps, the piping renewal in this embodiment is completed.

[0077] According to the above-described pipe cutting method, the cutting part 13 cuts the wall thickness of the pipe 10 by contacting it from the pipe axial direction, so that damage to the protective material 9 can be suppressed, and since the gas inflow means 23 inflows gas into the inside of the pipe 10 while the cutting part 13 is not cutting the pipe 10, chips generated by cutting can be reliably blown away by the gas. Therefore, since damage to the protective material 9 can be suppressed while hindering cutting due to accumulation of chips can be suppressed, the pipe 10 can be processed without any inconvenience.

[0078] Furthermore, during the return process, the insertion guide portion 22 is maintained inserted into the portion of the piping 10 that has not been cut in the axial direction of the piping 10, so that even if the feed process and return process are repeatedly performed, the cutting portion 13 can be prevented from shifting radially relative to the piping 10.

[0079] Furthermore, since the gas inflow means 23 injects gas into the pipe 10 at least at the timing when the feed step is started (first inflow time T1), the gas can be injected into the pipe 10 at the timing when the tip of the blade portion 130 is away from the cutting end surface 10a formed by the blade portion 130 cutting the pipe 10 by the return distance L2. Also, since the blade portion 130 is located away from the cutting end surface 10a by the return distance L2, which is longer than the cutting distance L3, at the first inflow time T1, the blade portion 130 is located closer to the inlet 4 than the range where the pipe 10 was cut in the previous cutting. Therefore, the chips generated by cutting can be reliably blown away by the gas.

[0080] Furthermore, the gas inflow means 23 flows the gas into the pipe 10 at least at the timing (second inflow time T2) immediately before the blade portion 130 comes into contact with the cutting end face 10a, so that the gas can be flowed into the pipe 10 at the timing when the blade portion 130 comes into contact with or is located close to the cutting end face 10a. By flowing the gas from the outlet 5 side at such a timing, the gas that has passed through the pipe 10 can hit the cutting portion 13 with almost the same pressure. Therefore, the pressure of the flowing gas makes it easier to blow away chips attached to the blade portion 130, so that the occurrence of poor cutting due to chips can be suppressed.

[0081] Furthermore, the gas inflow means 23 inflows gas into the pipe 10 at least at the timing (third inflow time T3) when the blade portion 130 contacts the cutting end face 10a and cuts the pipe 10, so that the frictional heat generated by cutting the pipe 10 can be cooled by the gas, and poor cutting caused by frictional heat (for example, the pipe 10 melted by frictional heat adhering to the blade portion 130) can be suppressed.

[0082] In addition, the gas inflow means 23 allows gas to flow into the pipe 10 at least at the timing when cutting of the pipe 10 is completed with the blade portion 130 abutting the cutting end face 10a, so that the blade portion 130 and the pipe 10 can be appropriately cooled at a timing when the pipe 10 and the cutting portion 13 are likely to be heated by frictional heat, thereby suppressing the occurrence of poor cutting due to frictional heat.

[0083] Furthermore, the gas inflow means 23 is configured to allow gas to flow into the piping 10 at least when the blade portion 130 is away from the cutting end face 10a by a cutting distance L3 or more, so that chips generated by cutting in the immediately preceding feed process can be reliably removed.

[0084] Moreover, the gas inflow means 23 is configured to inflow the gas from the other end side (the outlet 5 side) of the pipe 10, and the gas inflow means 23 inflows the gas into the pipe 10 at least at the timing during the return process (the fourth inflow time T4), so that when the gas is inflowed from the outlet 5 side of the pipe 10 while the blade portion 130 is moving toward the inlet 4 side, the force with which the gas and the chips blown by the gas hit the blade portion 130 becomes smaller than when they hit during the feed process. Therefore, the chips blown by the gas hit the blade portion 130 strongly, and it is possible to suppress the occurrence of cutting defects due to the chips sticking to the blade portion 130.

[0085] Furthermore, since the gas inflow means 23 is configured to flow gas from the other end side (outlet 5 side) of the piping 10 toward one end side (inlet 4 side), the gas flows from the narrow inner diameter side of the existing piping 8 where the piping 10 has not been cut toward the wide inner diameter side of the existing piping 8 where the piping 10 has been cut, chips can be removed efficiently.

[0086] In addition, since the drive unit 14 supplies a rotational force to the cutting unit 13 throughout the time the cutting cycle is being executed, the cutting unit 13 is in a rotating state while the cutting cycle is being executed, and this prevents chips flowing through the existing piping 8 by the gas from adhering to the cutting unit 13, thereby preventing cutting from being hindered by the chips.

[0087] Furthermore, the pipe cutting device 12 has a dust suction means for sucking up chips generated by cutting at one end side of the existing pipe 8, so that the chips can be sucked up by the dust suction means, thereby preventing the chips from flowing out of the existing pipe 8 and scattering to the outside.

[0088] An insertion guide portion 22 is provided at the tip of the cutting portion 13, the insertion guide portion 22 being smaller than the inner diameter of the pipe 10, extending along the axial direction of the pipe 10, and abutting the inner surface of the pipe 10 to prevent the cutting portion 13 from shifting radially relative to the pipe 10.The return distance in the return process is set to be shorter than the axial length of the insertion guide portion 22, so that when the cutting portion 13 is sent again into the pipe 10 after the return process, the cutting portion 13 can be prevented from shifting radially relative to the pipe 10.

[0089] According to the above-mentioned pipe cutting device 12, the cutting unit 13 cuts the wall thickness of the pipe 10 by contacting it from the pipe axial direction, so that damage to the protective material 9 can be suppressed, and the control unit controls the gas inflow means 23 to infuse gas into the inside of the pipe 10 while the cutting unit 13 is not cutting the pipe 10, so that chips generated by cutting can be reliably blown away by the gas. Therefore, since damage to the protective material 9 can be suppressed while hindering cutting due to accumulation of chips can be suppressed, the pipe 10 can be processed without any inconvenience.

[0090] In addition, the control unit sets the return distance to be shorter than the protruding length of the insertion guide portion 22 from the blade portion 130, so that during the return process, the insertion guide portion 22 is maintained inserted into the portion of the piping 10 that has not been cut in the axial direction, thereby preventing the cutting portion 13 from shifting radially relative to the piping 10 even when the feed process and return process are repeatedly performed.

[0091] Furthermore, the control unit controls the gas inflow means 23 to flow gas into the pipe 10 at least at the timing when the feed process starts (first inflow time T1), so that the gas can be flowed into the pipe 10 at the timing when the tip of the blade portion 130 is away from the cutting end surface 10a formed by the blade portion 130 cutting the pipe 10 by the return distance L2. Also, at the first inflow time T1, the blade portion 130 is located away from the cutting end surface 10a by the return distance L2, which is longer than the cutting distance L3, so that the blade portion 130 is located closer to the inlet 4 than the range where the pipe 10 was cut in the previous cutting. Therefore, the chips generated by cutting can be reliably blown away by the gas.

[0092] Furthermore, the control unit controls the gas inflow means 23 to flow gas into the piping 10 at least at the timing (second inflow time T2) immediately before the blade portion 130 comes into contact with the cutting end face 10a, so that the gas can be flowed into the piping 10 at the timing when the blade portion 130 comes into contact with or is located close to the cutting end face 10a. By flowing the gas from the outlet 5 side at such a timing, the gas that has passed through the piping 10 can hit the cutting portion 13 with almost the same pressure. Therefore, the pressure of the flowing gas makes it easier to blow away chips attached to the blade portion 130, so that the occurrence of poor cutting due to chips can be suppressed.

[0093] Furthermore, the control unit controls the gas inflow means 23 to flow gas into the pipe 10 at least at the timing (third inflow time T3) when the blade portion 130 contacts the cutting end face 10a and cuts the pipe 10, so that the frictional heat generated by cutting the pipe 10 can be cooled by the gas, and poor cutting caused by frictional heat (for example, the pipe 10 melted by frictional heat adhering to the blade portion 130) can be suppressed.

[0094] In addition, the control unit controls the control unit to allow gas to flow into the pipe 10 at least at the timing when cutting of the pipe 10 is completed with the blade portion 130 abutting the cutting end face 10a, so that the blade portion 130 and the pipe 10 can be appropriately cooled at a timing when the pipe 10 and the cutting portion 13 are likely to be heated by frictional heat, and the occurrence of poor cutting due to frictional heat can be suppressed.

[0095] Furthermore, the gas inflow means 23 is configured to inflow the gas from the other end side (the outlet 5 side) of the pipe 10, and the control unit controls the gas inflow means 23 to inflow the gas into the pipe 10 at least at the timing during the return process (the fourth inflow time T4), so that when the gas is inflowed from the outlet 5 side of the pipe 10 while the blade portion 130 is moving toward the inlet 4 side, the force with which the gas and the chips blown by the gas hit the blade portion 130 becomes smaller than when they hit during the feed process. Therefore, the chips blown by the gas hit the blade portion 130 strongly, and it is possible to suppress the occurrence of cutting defects due to the chips sticking to the blade portion 130.

[0096] In addition, the control unit controls the gas inflow means 23 to flow gas into the piping 10 at least when the blade portion 130 is away from the cutting end face 10a by the cutting distance L3 or more, so that chips generated by cutting in the immediately preceding feed process can be reliably removed.

[0097] Furthermore, the control unit controls the drive unit 14 to supply a rotational force to the cutting unit 13 throughout the time the cutting cycle is being executed, so that the cutting unit 13 is in a rotating state while the cutting cycle is being executed, and this prevents chips flowing through the existing piping 8 by the gas from adhering to the cutting unit 13, thereby preventing cutting from being hindered by the chips.

[0098] According to the above-mentioned method of controlling the pipe cutting device 12, the cutting part 13 of the pipe cutting device 12 cuts the wall thickness of the pipe 10 by contacting it from the pipe axial direction, so that damage to the protective material 9 can be suppressed, and since the gas inflow means 23 is controlled to infuse gas into the inside of the pipe 10 while the cutting part 13 is not cutting the pipe 10, chips generated by cutting can be reliably blown away by the gas. Therefore, damage to the protective material 9 can be suppressed while hindering cutting due to accumulation of chips can be suppressed, so that the pipe 10 can be processed without any inconvenience.

[0099] In addition, since the return distance is controlled to be shorter than the protruding length of the insertion guide portion 22 from the blade portion 130, the insertion guide portion 22 is maintained inserted into the portion of the piping 10 that has not been cut in the axial direction during the return process, so that the cutting portion 13 can be prevented from shifting radially relative to the piping 10 even if the feed process and return process are repeatedly performed.

[0100] Furthermore, since the gas inflow means 23 is controlled to inject gas into the pipe 10 at least at the timing when the feed step is started (first inflow time T1), the gas can be injected into the pipe 10 at the timing when the tip of the blade portion 130 is a return distance L2 away from the cutting end surface 10a formed by the blade portion 130 cutting the pipe 10. Also, since the blade portion 130 is located a return distance L2 longer than the cutting distance L3 away from the cutting end surface 10a at the first inflow time T1, the blade portion 130 is located closer to the inlet 4 than the range where the pipe 10 was cut in the previous cutting. Therefore, the chips generated by cutting can be reliably blown away by the gas.

[0101] Furthermore, the gas inflow means 23 is controlled to flow gas into the piping 10 at least at the timing (second inflow time T2) immediately before the blade portion 130 comes into contact with the cutting end face 10a, so that the gas can be flowed into the piping 10 at the timing when the blade portion 130 comes into contact with or is located close to the cutting end face 10a. By flowing the gas from the outlet 5 side at such a timing, the gas that has passed through the piping 10 can hit the cutting portion 13 with almost the same pressure. Therefore, the pressure of the flowing gas makes it easier to blow away chips attached to the blade portion 130, so that the occurrence of poor cutting due to chips can be suppressed.

[0102] Furthermore, the gas inflow means 23 is controlled to inflow gas into the pipe 10 at least at the timing (third inflow time T3) when the blade portion 130 contacts the cutting end face 10a and cuts the pipe 10, so that the frictional heat generated by cutting the pipe 10 can be cooled by the gas, and poor cutting caused by frictional heat (for example, the pipe 10 melted by frictional heat adhering to the blade portion 130) can be suppressed.

[0103] Furthermore, the gas inflow means 23 is controlled to allow gas to flow into the pipe 10 at least at the timing when cutting of the pipe 10 is completed with the blade portion 130 abutting the cutting end face 10a, so that the blade portion 130 and the pipe 10 can be appropriately cooled at a timing when the pipe 10 and the cutting portion 13 are likely to become heated by frictional heat, thereby suppressing the occurrence of poor cutting due to frictional heat.

[0104] Furthermore, the gas inflow means 23 is configured to allow gas to flow in from the other end side (the outlet 5 side) of the piping 10, and is controlled to allow gas to flow into the piping 10 at least at the timing during the return process (the fourth inflow time T4), so that when gas is allowed to flow in from the outlet 5 side of the piping 10 while the blade portion 130 is moving toward the inlet 4 side, the force with which the gas and the chips blown by the gas hit the blade portion 130 becomes smaller than when they hit in the middle of the feed process. Therefore, the chips blown by the gas hit the blade portion 130 strongly, and it is possible to suppress the occurrence of cutting defects due to the chips sticking to the blade portion 130.

[0105] In addition, the gas inflow means 23 is controlled to allow gas to flow into the piping 10 at least when the blade portion 130 is away from the cutting end face 10a by the cutting distance L3 or more, so that chips generated by cutting in the immediately preceding feed process can be reliably removed.

[0106] Furthermore, since the drive unit 14 is controlled to supply a rotational force to the cutting unit 13 throughout the time the cutting cycle is being executed, the cutting unit 13 is in a rotating state while the cutting cycle is being executed, and this prevents chips flowing through the existing piping 8 by the gas from adhering to the cutting unit 13, thereby preventing cutting from being hindered by the chips.

[0107] Although an embodiment of the present invention has been described above by way of example, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0108] For example, the gas inflow means 23 has been described as being configured to intermittently inflow gas into the piping 10, but this is not limited to the above case, and the gas can also be configured to constantly inflow gas into the existing piping 8 during the cutting cycle.

[0109] Further, the pipe cutting device 12 has been described as cutting the entire wall thickness of the pipe 10, but the present invention is not limited to this case and may be configured to cut only a portion of the wall thickness of the pipe 10.

[0110] Furthermore, although the gas inflow means 23 has been described as being configured to allow gas to flow into the piping 10 by sending gas from the other end side of the piping 10, it can also be configured to allow gas to flow in from the other end side of the piping 10 by sucking gas from one end side of the existing piping 8.

[0111] In addition, the movement of the cutting part 13 in the axial direction of the pipe 10 is controlled by the control unit in the above embodiment, but this is not limited to the above embodiment, and the movement of the cutting part 13 can also be managed by the operator.

[0112] Furthermore, although the case has been described where a groove is formed in the cut portion 13 to allow gas to flow in the axial direction of the tube, the present invention is not limited to such a case, and the cut portion 13 may also be configured so that no groove is formed therein.

[0113] In addition, although the connecting portion 15 has been described as being pulled by the rope body 20 and moving to one side of the piping 10, the present invention is not limited to this configuration and can also be configured to be pushed out by a moving means and move to one side of the piping 10.

[0114] Furthermore, although the case has been described where the feed process and the return process are executed successively, this is not limited to the case. For example, it is also possible to configure the apparatus so that a stop process is provided between the return process and the feed process, and the movement of the cutting part 13 is temporarily stopped when the cutting part 13 is separated from the end face.

[0115] In addition, although the case has been described where the moving means and the gas inflow means 23 operate in synchronization, they may not be synchronized, and the phase of the timing at which the moving means sends and returns the cutting portion 13 may be out of phase with the timing at which the gas inflow means 23 inflows gas and stops the inflow. [Explanation of symbols]

[0116] 1...Hot water supply pipe, 2...Water supply pipe, 3...Floor surface, 4...Inlet, 5...Outlet, 6...Header material, 7...Faucet, 8...Existing pipe, 9...Protective material, 10...Pipe, 11...New pipe, 12...Pipe cutting device, 13...Cutting part, 130...Blade part, 14 ... drive unit, 15 ... connection unit, 151 ... mounting unit, 16 ... handle, 17 ... feed unit, 171 ... feed machine, 172 ... feed main unit, 173 ... inlet side auxiliary pipe, 174 ... auxiliary pipe mounting jig, 175 ... window unit, 176 ... inlet connection unit, 177 ... auxiliary pipe connection unit, 178 ... chip discharge unit, 18 ... traction unit, 181 ... winding machine, 182 ... outlet side auxiliary pipe, 183 ... winding main unit, 19 ...shaft, 191...joint portion, 20...rope body, 20A...tip side rope body, 20B...rear end side rope body, 21...middle guide portion, 22...insertion guide portion, 221...guide base portion, 222...guide tip portion, 23...gas inflow means, 24...compressor, 241...compressor main body portion, 242...inflow pipe, 25...dust collector, 251...suction portion, 252...dust collection pipe, 253...filter portion, 26...piping insertion tool

Claims

1. A pipe cutting method using a pipe cutting device including: a cutting unit that rotates an existing pipe, in which a protective material is provided so as to cover a radially outer side of the pipe, about a center in a pipe axial direction and abuts against the pipe in the pipe axial direction to cut a wall thickness of the pipe; a driving unit that applies a rotational force to the cutting unit; a connecting unit that is configured to be able to connect the cutting unit and the driving unit so as to transmit the rotational force; and a gas inflow means that flows a gas into the inside of the pipe, a feed process in which the cutting portion is moved from one end side to the other end side in the axial direction of the pipe, and a wall thickness of the pipe is removed during a portion of the movement of the cutting portion from the one end side to the other end side; and a return process in which the cutting portion that has moved from the one end side to the other end side of the pipe in the feed process is moved from the other end side to the one end side, a feed distance, which is a distance by which the cutting part is moved from one end side to the other end side in the feed step, is longer than a return distance, which is a distance by which the cutting part is moved from the other end side to the one end side in the return step; In the feeding step, a cutting distance, which is a distance by which the cutting portion cuts the pipe, is set shorter than the return distance, A pipe cutting method comprising the steps of: causing the gas to flow into the inside of the pipe by the gas inflow means during the feed step and the return step, except for a period during which the cutting part is cutting the pipe in at least the feed step.

2. The cutting portion includes a blade portion that cuts the pipe and an insertion guide portion that protrudes from a tip side of the blade portion, the insertion guide portion is configured to be inserted into the inside of the pipe along a pipe axis direction and to guide a movement of the blade portion in the pipe axis direction, The pipe cutting method according to claim 1 , wherein a return distance in the return step is set to be shorter than a protruding length of the insertion guide portion.

3. the device comprises: a cutting unit that rotates an existing pipe, in which a protective material is provided to cover the outer diameter of the pipe, about a center in a pipe axial direction and abuts against the pipe in the pipe axial direction to cut a wall thickness of the pipe; a drive unit that applies a rotational force to the cutting unit; a connection unit that is configured to be connectable between the cutting unit and the drive unit so as to transmit a rotational force; a moving means that moves the cutting unit to one side and the other side in the pipe axial direction along the pipe axial direction of the pipe; a gas inflow means that flows a gas into the inside of the pipe; and a control unit that controls the entire device; The control unit is a feed process in which the cutting portion is moved from one end side to the other end side in the axial direction of the pipe, and a wall thickness of the pipe is removed during a portion of the movement of the cutting portion from the one end side to the other end side; and a return process in which the cutting portion that has moved from the one end side to the other end side of the pipe in the feed process is moved from the other end side to the one end side, a feed distance, which is a distance by which the cutting part is moved from one end side to the other end side in the feed step, is longer than a return distance, which is a distance by which the cutting part is moved from the other end side to the one end side in the return step; In the feeding step, a cutting distance, which is a distance by which the cutting portion cuts the pipe, is set to be shorter than the return distance, A pipe cutting device that controls the gas inflow means to infuse gas into the inside of the pipe during the feed process and the return process, at least except for the time when the cutting part is cutting the pipe during the feed process.

4. A control method for a pipe cutting device comprising: a cutting unit that rotates an existing pipe, in which a protective material is provided to cover a radially outer side of the pipe, about a center in a pipe axial direction and abuts against the pipe in the pipe axial direction to cut a wall thickness of the pipe; a drive unit that applies a rotational force to the cutting unit; a connection unit that is configured to be able to connect the cutting unit and the drive unit so as to transmit the rotational force; a moving unit that moves the cutting unit to one side and the other side in the pipe axial direction along the pipe axial direction of the pipe; and a gas inflow unit that inflows gas into the inside of the pipe, a feed process in which the cutting portion is moved from one end side to the other end side in the axial direction of the pipe, and a wall thickness of the pipe is removed during a portion of the movement of the cutting portion from the one end side to the other end side; and a return process in which the cutting portion that has moved from the one end side to the other end side of the pipe in the feed process is moved from the other end side to the one end side, a feed distance, which is a distance by which the cutting part is moved from one end side to the other end side in the feed step, is longer than a return distance, which is a distance by which the cutting part is moved from the other end side to the one end side in the return step; In the feeding step, a cutting distance, which is a distance by which the cutting portion cuts the pipe, is set to be shorter than the return distance, A control method for a pipe cutting device, which controls the gas inflow means to infuse gas into the inside of the pipe during the feed process and the return process, at least except for the time when the cutting part is cutting the pipe during the feed process.

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