Pipe removal method

Abstract

To provide a piping withdrawal method which can reliably withdraw piping.SOLUTION: A piping withdrawal method for withdrawing piping 10, which is covered at least at a middle portion in a pipe axial direction, in the pipe axial direction comprises a withdrawal step for withdrawing the piping 10 to one side in the pipe axial direction with one end part in the pipe axial direction set as a front part, and the other end part set as a rear part. In the withdrawal step, a pipe end face of the other end part of the piping 10 is pushed to one side, one side in the pipe axial direction rather than the pipe end face of the other end part of the piping 10 is held and pulled out, and the piping 10 is thereby withdrawn to one side in the pipe axial direction.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a method for removing a pipe. [Background technology]

[0002] As an example of a device for extracting a pipe whose axial direction is at least partly buried in concrete, there is a pipe extraction tool described in Patent Document 1. This pipe extraction tool is composed of a block with a tapered outer circumferential surface that holds the pipe by contacting the outer circumferential surface of the pipe to be extracted, one plate and another plate through which the pipe passes and having a hole drilled around the periphery large enough for the block to fit, which are connected with three bolts and assembled and fastened with nuts, a pipe holder that holds the block, a cylinder shaft connected to the one plate, a cylinder that hydraulically lifts the cylinder shaft upward, and a cylinder holder composed of three bolts and nuts that connect the one plate on which the cylinder is installed to the other plate that is installed on the floor.

[0003] According to the above configuration, when the hydraulic pressure of the cylinder is released to place the tube holder in the lowest position, the top is placed against the outer circumferential surface of the tube and the other plate of the tube holder is attached, and hydraulic pressure is applied to the cylinder to move the cylinder shaft upward, the other plate engages with the tapered outer circumferential surface of the top, the tube holder moves upward, the top bites into the tube and moves above the tube holder, and the tube also moves upward. In this way, the old tube can be pulled out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-203508 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when using the pipe extraction tool to extract the pipe, if the pipe to be extracted is long or deteriorated, there is a risk that the pipe will break during extraction, and a part of the pipe will remain in the concrete. This problem occurs not only when the pipe is extracted upward, but also when the pipe is generally extracted. Furthermore, this problem occurs not only when a part of the pipe is buried in the concrete, but also when the pipe is hidden by being installed on the back surface of the ceiling or on a slab under the floor, that is, it occurs generally when extracting a pipe whose middle part in the axial direction is covered.

[0006] Therefore, an object of the present invention is to provide a pipe removal method that can reliably remove the pipe. [Means for solving the problem]

[0007] The present invention is a pipe pulling method for pulling a pipe in a pipe axial direction, the pipe being covered at least in the middle portion thereof, the method including a pulling step for pulling the pipe to one side in the pipe axial direction with one end of the pipe in the pipe axial direction at the front and the other end at the rear, the pulling step being a step of pushing a pipe end face of the other end of the pipe to one side, and pulling the pipe to one side in the pipe axial direction by holding and pulling the pipe on the one side of the pipe end face of the other end of the pipe.

[0008] According to the above-described construction method, in the pulling process, the pipe end face of the other end of the piping is pushed to one side, and the pipe is pulled while being held on one side in the pipe axis direction relative to the pipe end face of the other end. Therefore, when the pipe is pulled to one side in the pipe axis direction, the pipe can be prevented from breaking in the pipe axis direction. Effect of the Invention

[0009] Therefore, according to the present invention, the pipe end face of the other end of the piping is pushed to one side, and the pipe is pulled by holding one side of the pipe end face of the other end of the piping in the pipe axial direction and pulling the pipe to one side in the pipe axial direction, thereby enabling the pipe to be removed reliably. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a pipe to which a pipe removal method according to one embodiment of the present invention is applied, and is a cross-sectional view of the pipe through which a rope body is inserted. [Diagram 2] FIG. 2 is a cross-sectional view of a pipe illustrating the pipe cutting device according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of a pipe illustrating a cutting blade cutting step according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the pipe illustrating a pipe removal process according to the embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of the piping showing the outlet side removal process of the piping according to the embodiment, where (a) shows the remaining piping cutting process, (b) shows the tool removal process, and (c) shows the piping removal process. [Figure 6] FIG. 6 is a front view of the cutting portion in the same embodiment. [Figure 7] FIG. 7 is a cross-sectional view of the pipe showing the intermediate removal process according to the embodiment, in which the cord body is inserted. [Figure 8] FIG. 8 is a cross-sectional view of the pipe illustrating an arrangement step according to the embodiment, where (a) illustrates the other-side arrangement step, and (b) illustrates the one-side arrangement step. [Figure 9] FIG. 9 is a cross-sectional view of the pipe illustrating the pipe removal step according to the embodiment. [Figure 10] FIG. 10 is a half cross-sectional view of the puller according to the embodiment. [Figure 11] FIG. 11 is a half cross-sectional view of the pressing tool according to the same embodiment. [Figure 12] FIG. 12 is a front view of a puller according to another embodiment. [Figure 13]FIG. 13 is a half cross-sectional view of a puller according to another embodiment, where (a) shows a state in which the hook part is stored, and (b) shows a state in which the hook part is protruding. [Figure 14] FIG. 14 is a front view of a pulling means according to another embodiment, where (a) shows a state in which the hook portion is stored, and (b) shows a state in which the hook portion is protruding. [Figure 15] FIG. 15 is a view showing a pulling means according to another embodiment, and is a half cross-sectional view of the pulling tool. [Figure 16] FIG. 16 is a view showing a pushing means according to another embodiment, and is a half sectional view of a puller. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A pipe removal method according to one embodiment of the present invention will be described below with reference to Fig. 1 to Fig. 11. This pipe removal method is used as a pipe renewal method in which, for example, an old internal pipe 10, which is an existing pipe (hereinafter simply referred to as a pipe) arranged inside a protective pipe 9, is cut in the circumferential direction by a pipe cutting device 20 (see Fig. 2), divided in the pipe axial direction, and then removed, and renewed with a new pipe (not shown) that is arranged inside the protective pipe 9 in place of the pipe 10.

[0012] In the following description, the pipe axis direction is the direction along the axial direction of the pipe 10, and one side and the other side are defined in the pipe axis direction. Here, the one side in the pipe axis direction is the front side in the direction in which the pipe 10 is removed from the protective pipe 9, and the other side in the pipe axis direction is the rear side in the direction in which the pipe 10 is removed from the protective pipe 9. In addition, from the perspective of the worker who performs the pipe renewal, the closer side in the pipe axis direction is referred to as the "front side" and the farther side is referred to as the "rear side". For convenience of explanation, the left end of the pipe 10 will be referred to as the "inlet 4" and the right end of the pipe 10 will be referred to as the "outlet 5" as shown in FIG. 1.

[0013] As shown in Fig. 1, existing piping 1 (e.g., hot water supply piping and cold water supply piping) in a building is composed of a protective pipe 9 and piping 10 arranged inside the protective pipe 9. At least a middle portion of the piping 10 in the axial direction is covered. In this embodiment, the piping 10 is inserted into the protective pipe 9, so that a middle portion of the piping in the axial direction is covered.

[0014] The protective pipe 9 is made of a thermal insulation material such as foamed resin. The existing pipe 1 is tubular, and is formed by inserting a flexible pipe 10 made of a polyethylene pipe, a cross-linked polyethylene pipe, an aluminum three-layer pipe, or the like, into the protective pipe 9. The pipe 10 is flexible and can be bent. The new pipe, like the pipe 10, is made of 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.

[0015] A specific description of the pipe renewal method according to this embodiment includes (1) a preparation step as a preliminary step to pipe renewal, (2) a removal step of removing the pipe 10 from the protective pipe 9, and (3) an insertion step of inserting a new pipe by pulling it from the back side to the front side with a pipe insertion tool after the removal step. Note that in this pipe renewal method, the protective pipe 9, the pipe 10, and the new pipe have circular cross sections.

[0016] (1) The preparation process will be described. In the preparation process of this embodiment, for each existing pipe 1, the area of ​​the existing pipe 1 that is exposed to the floor surface is regarded as the free end. Therefore, the preparation process of this embodiment is a removal process in which one end of the pipe 10 of the existing pipe 1 is removed from the header member (not shown) to form the inlet 4, and the other end of the pipe 10 of the existing pipe 1 is removed from the faucet to form the outlet 5. Note that the preparation process may include preparations required for pipe renewal (for example, preparation of a pipe cutting device 20 and a new pipe) in addition to the above description.

[0017] Next, the (2) pulling process will be described. The pulling process is a process for removing the pipe 10 by pulling it out from the protective pipe 9. The pulling process is performed by applying a pulling method for the pipe 10. In the pulling process of this embodiment, the pipe 10 is cut in the circumferential direction, separated into the cut pipes 10a, 10d, and 10e in the pipe axial direction, and the cut pipes 10a, 10d, and 10e are pulled out from the protective pipe 9, thereby pulling the pipe 10 out from the protective pipe 9. Here, in the description of this embodiment, the remaining pipe 10b (see FIG. 4) arranged on the outlet 5 side will be described on the premise that it is impossible to pull out from the protective pipe 9. Therefore, in this embodiment, a case in which the cut pipes 10a, 10d, and 10e formed by separating the pipe 10 into three are pulled out will be described. Therefore, the pulling process of this embodiment includes an inlet side pulling process (2-1), an outlet side pulling process (2-2), and an intermediate pulling process (2-3).

[0018] In the (2-1) inlet side extraction process, the cut pipe 10a is extracted from the protective pipe 9. In this embodiment, the worker extracts the cut pipe 10a from the inlet 4 side. Therefore, in describing the inlet side extraction process, the inlet 4 side is one side in the pipe axial direction and the front side, and the outlet 5 side is the other side in the pipe axial direction and the back side. The (2-1) inlet side extraction process includes a (2-1A) pipe cutting process and a (2-1E) pipe extraction process.

[0019] As shown in Figures 1 to 3, the pipe cutting process includes an insertion process (2-1B) of passing the rope body main body 31 through the pipe 10, a positioning process (2-1C) performed after the insertion process of positioning the cutting portion 22 at a predetermined position on the pipe 10, and a cutting blade cutting process (2-1D) performed after the positioning process of cutting the predetermined position of the pipe 10 with the cutting portion 22.

[0020] Before describing (2-1B) the insertion step, (2-1C) the arrangement step, and (2-1D) the cutting blade cutting step, the pipe cutting device 20 used in the pipe cutting step will be described. The pipe cutting device 20 has the following configuration. That is, as shown in Figures 2 and 3, it includes a drive unit 23, a transmission shaft 24, a cutting unit 22, and a leading unit 25, in that order from the inlet 4 side to the outlet 5 side.

[0021] 2, the driving unit 23 is a device that applies a rotational force to the cutting unit 22 via a transmission shaft 24. A typical rotary power tool is used as the driving unit 23, and a driving connection shaft part (handle) 27 is detachably connected to the tip of the main body 26.

[0022] The transmission shaft 24 includes a drive connecting shaft portion 27, a multiple shaft portion 28, and a flexible shaft portion 29. As described above, the drive connecting shaft portion 27 is configured to be detachable from the tip of the main body 26 of the drive unit 23.

[0023] The multiple shaft portion 28 is a rod-shaped member extending in the axial direction of the drive connecting shaft portion 27. The multiple shaft portion 28 includes a shaft 19 (outer shaft portion) and a rod-shaped connecting rod portion (inner shaft portion) 19A provided inside the shaft 19. The shaft 19 is made of a metal flexible tube and has flexibility in a radial direction intersecting the axial direction. A first support portion 35 configured to support the flexible shaft portion 29, which will be described later, is disposed at the tip of the shaft 19. The first support portion 35 is configured to have a larger diameter than the flexible shaft portion 29, and is disposed in the pipe 10 to be cut, and is configured to support the flexible shaft portion 29. Specifically, the outer diameter of the first support portion 35 is approximately the same as the inner diameter of the pipe 10, and is configured so that the movement in the radial direction is restricted by the inner peripheral surface of the pipe 10. Further, the first support portion 35 supports the flexible shaft portion 29 at the radial center, and is supported so that at least the tip portion of the flexible shaft portion 29 protrudes toward the tip side. In this embodiment, the first support portion 35 supports the base end portion of the flexible shaft portion 29.

[0024] The connecting rod portion 19A is provided from the tip of the drive connecting shaft portion 27 to the tip of the shaft 19, and is connected to the tip of the drive connecting shaft portion 27. In this embodiment, the connecting rod portion 19A is composed of a torsion coil spring that is linear in its natural state. Although the connecting rod portion 19A is composed of a torsion coil spring, since it is disposed inside the shaft 19, even when it rotates by receiving the rotational drive from the drive portion 23, the range of its flexibility is limited to the amount of bending that corresponds to the gap formed between the inner peripheral surface of the shaft 19 and the outer peripheral surface of the connecting rod portion 19A.

[0025] The flexible shaft portion 29 has flexibility so that the central axis curves and bends, and is disposed within a certain range in the tube axis direction on the other side (the outlet 5 side) of the first support portion 35 in the tube axis direction. In this embodiment, the flexible shaft portion 29 is a portion that extends from the connecting rod portion 19A in the tube axis direction, and is integrally formed with the connecting rod portion 19A. In other words, the flexible shaft portion 29 is composed of a torsion coil spring. Alternatively, the flexible shaft portion 29 can be configured as a separate member having a different length in the tube axis direction, and is connected to the connecting rod portion 19A by a screw.

[0026] Since the flexible shaft 29 is free to rotate radially outward, it rotates by an amount corresponding to the rotation from the drive unit 23. A support ring 36 for mounting the cutting unit 22 is fitted onto the tip of the flexible shaft 29. A rod-shaped member 37 for supporting the cutting unit 22 on the inlet 4 side is disposed in the center of the tip of the support ring 36 (flexible shaft 29) (see FIG. 6). A male thread that screws into the cutting unit 22 is formed on the outer periphery of the rod-shaped member 37.

[0027] As shown in Fig. 6, the cutting section 22 includes a base 38 and a cutting blade 39. The base 38 is formed cylindrically and extends in the tube axial direction, and as shown in Fig. 6, one base end face 40 and the other base end face 41 on both sides are formed parallel to each other so as to be perpendicular to the tube axial direction. A central hole 42 is formed in the center of the base 38 (between the one base end face 40 and the other base end face 41), and a female thread is formed in the central hole 42. The male thread of the rod-shaped member 37 is screwed into the inlet 4 side of the central hole 42. The male thread of one connector 43, which will be described later, is screwed into the outlet 5 side of the central hole 42.

[0028] The cutting blade portion 39 is integrally formed from an outer peripheral surface on one side of the central axis direction of the base portion 38, i.e., from one base end surface 40 side, protruding along the radial direction of the base portion 38. The cutting blade portion 39 is composed of an outer diameter surface 44, a leading side surface (not numbered) which is in the rotation direction of the outer diameter surface 44 (specifically, the counterclockwise direction when the cutting portion 22 in FIG. 6 is viewed from the left side) and leads the rotation of the cutting portion 22, and serves as a scooping surface, a trailing side surface 46 which is in the opposite rotation direction of the outer diameter surface 44 (specifically, the clockwise direction when the cutting portion 22 in FIG. 6 is viewed from the left side), and corresponds to the leading side surface, and a first blade end surface 47 and a second blade end surface 48 which are on both sides in the tube axial direction. The leading side surface is a surface which stands in the radial direction of the base portion 38.

[0029] Additionally, the contact area between the outer diameter surface 44 and the leading side surface is defined as a cutting edge 49 that cuts the pipe 10 from the inside. The outer diameter surface 44 is defined as an inclined surface that inclines in the counter-rotation direction from the cutting edge 49. Note that the outer diameter surface 44 including the cutting edge 49 and a part of the one blade end surface 47 and the other blade end surface 48 are set as a bit (formed from super steel, for example) separate from the other cutting blade portion 39.

[0030] 2 and 3, the leading portion 25 is a portion that is inserted into the pipe 10 prior to the cutting portion 22. The leading portion 25 includes a leading connecting portion 50 and a rope body 51.

[0031] Further, the preceding connection part 50 includes a flexible connection part 52 and a second support part 53. The flexible connection part 52 includes the one connector 43 attached to the other side of the cutting part 22 in the pipe axis direction, a flexible connection part main body 54 attached to the one connector 43, and a second connector 55 attached to the flexible connection part main body 54, which are arranged in this order from the inlet 4 to the outlet 5 of the pipe 10. In this embodiment, the flexible connection part main body 54 is made of a single wire. Moreover, the flexible connection part main body 54 includes the one connector 43 arranged on the inlet 4 side and the other connector 55 arranged on the outlet 5 side, as described above, on both sides in the pipe axis direction. The flexible connection part main body 54 includes annular members 56, 56 that fit the flexible connection part main body 54 on the one connector 43 side and the other connector 55 side, respectively. The annular members 56, 56 have a circular outer circumferential surface. Since the flexible connection body 54 is made of wire, the area between the annular members 56, 56 is flexible, but the areas between the one connector 43 and the annular members 56, 56, and the areas between the other connector 55 and the annular members 56, 56 are not flexible. Here, in the flexible connection body 54, the areas between the annular members 56, 56 that are flexible are referred to as flexible portions 56A.

[0032] The one-way connector 43 is a member attached to the other side (the outlet 5 side) of the cutting part 22 in the pipe axis direction and connects the flexible connector main body 54. The one-way connector 43 has a central rod 57 formed therein that screws into the female thread of the central hole 42 of the cutting part 22 (see FIG. 6). The one-way connector 43 also has a one-way hole portion 58 formed therein for connecting an end of the flexible connector main body 54.

[0033] The other connector 55 is a member that supports the other side (the outlet 5 side) of the flexible connector main body 54 in the pipe axis direction, and is connected to the second support part 53 described later. In addition, the other connector 55 is formed with an other hole part 59 for connecting an end part of the flexible connector main body 54.

[0034] The second support part 53 is composed of a bearing jig. The second support part 53 includes a lid part 60 and a jig body 61. The jig body 61 is connected to the connector 62 on the other side (the outlet 5 side) in the pipe axial direction. The jig body 61 is connected to the lid part 60 by a bearing, and the lid part 60 and the jig body 61 are configured to be relatively rotatable with each other in the pipe axial direction. The second support part 53 has a circular outer periphery and is configured to have a larger diameter than the flexible connection part body 54. The second support part 53 is arranged in the pipe 10 to be cut and configured to support the flexible connection part body 54. Specifically, the second support part 53 is configured such that its outer diameter is approximately the same as the inner diameter of the pipe 10 and its radial movement is restricted by the inner peripheral surface of the pipe 10. The second support part 53 also supports the flexible connection part 52 at the center in the radial direction.

[0035] The rope body 51 includes a connector 62 attached to a jig body 61 of the second support portion 53, and a rope body main body 31 connected to the connector 62. The rope body main body 31 is made of a wire, and is formed with an outer diameter smaller than the inner diameter of the pipe 10. This rope body main body 31 is extended to the outlet 5, and the portion extended to the outlet 5 is wound around a drivable winch or the like (not shown).

[0036] Next, (2-1B) the insertion step, (2-1C) the arrangement step, and (2-1D) the cutting blade cutting step will be described. First, (2-1B) the insertion step is a step of passing the rope body main body 31 through the piping 10 as described above. In this case, the insertion step is a step of passing the rope body main body 31 from the outlet 5 of the piping 10 toward the inlet 4 (see FIG. 1). The rope body main body 31 is a wire formed with an outer diameter smaller than the inner diameter of the piping 10. This makes the insertion smooth.

[0037] (2-1C) The arrangement step will be described. The arrangement step is a step of arranging the cutting part 22 at a cutting position, which is a midway position in the axial direction of the pipe 10 to be cut, and is performed by inserting an assembly in which the cutting part 22 is attached to the tip of the flexible shaft part 29 into the pipe 10 from the inlet 4 side. Specifically, as shown in FIG. 2, the arrangement step is a step of attaching the cutting part 22 to the rope body main body 31 and arranging it at a predetermined position 10c inside the pipe 10. In the arrangement step, an assembly consisting of the transmission shaft 24, the cutting part 22, and the preceding connecting part 50 is attached to the end of the rope body main body 31 protruding from the inlet 4. It is preferable that the transmission shaft 24, the cutting part 22, and the preceding connecting part 50 are previously assembled together before the pipe cutting step. At this time, the male thread of the rod-shaped member 37 is screwed into the central hole 42 of the base 38 of the cutting portion 22 on the inlet 4 side, and the male thread of the one connector 43 is screwed into the central hole 42 on the outlet 5 side.

[0038] In the arrangement step, the connector 62 is directly attached to the rope body 31 protruding from the inlet 4. Then, the winch is driven to pull the rope body 31 so as to draw it into the inside of the pipe 10, and the second support part 53, the flexible connecting part 52, the cutting part 22, the flexible shaft part 29, and the multiple shaft part 28 are inserted into the pipe 10. The pulling direction (also called the insertion direction) is shown by the arrow in FIG. 2. Furthermore, the rope body 31 is pulled to arrange the cutting part 22 at a predetermined position in the pipe 10. At this time, by knowing in advance the lengths of the second support part 53, the flexible connecting part 52, the cutting part 22, the flexible shaft part 29, and the multiple shaft part 28 in the pipe axial direction, it can be known whether the cutting part 22 is at the predetermined position. Here, the position of the cutting portion 22, which is the cutting position of the pipe 10, is any position in the pipe axial direction of the middle part of the pipe 10 covered with the protective pipe 9, for example, from the inlet 4 toward the outlet 5 side of the pipe 10, where the first curved part has passed. In this embodiment, the pipe 10 is cut into three pieces and removed, so that the first cut is made to a length that is half of the middle part on the inlet 4 side or shorter than that. Then, when the cutting portion 22 reaches a predetermined position, the cable body main body 31 stops pulling, and the cutting portion 22 is stretched by the flexible shaft portion 29 and the flexible connecting portion 52. This completes the arrangement process.

[0039] (2-1D) The cutting blade cutting step will be described. The cutting blade cutting step is a step of cutting a predetermined position of the pipe 10 with the cutting part 22 as shown in Fig. 3. In the cutting blade cutting step, the driving part 23 is attached to the driving connection shaft part 27.

[0040] By mounting the driving unit 23 on the driving connection shaft 27, the connecting rod 19A becomes rotatable while the shaft 19 of the multiple shafts 28 is fixed, and therefore the flexible shaft 29 which is integral with the connecting rod 19A becomes rotatable. In the disposing step, the cable body 31 is stopped from being pulled, and the flexible connection body 54 of the flexible connection 52 is made of a wire and therefore has flexibility. Therefore, when the flexible shaft 29 is rotated by the rotational driving force of the driving unit 23, the cutting portion 22 rotates around the central axis of the flexible shaft 29. Then, the flexible portion 56A of the flexible connection body 54 rotates around the central axis to rotate with the rotation of the flexible shaft 29. In this way, the cutting portion 22 is held by the flexible shaft portion 29 on the inlet 4 side and by the flexible connecting portion main body 54 (flexible connecting portion 52) on the outlet 5 side, and rotates around the rotation center CL of the cutting portion 22 (see Figure 6) within the piping 10.

[0041] A central hole 42 is formed in the center of the base 38, and the cutting blade 39 protrudes from one base end face 40 of the base 38, so that the center of gravity of the cutting portion 22 is not at the center of the base 38 but at a position offset from the center of the central hole 42. However, since the cutting portion 22 rotates around the rod-shaped member 37 and one connector 43 that pass through the central hole 42, there is no relationship between the position of the center of gravity of the cutting portion 22 and the rotation of the cutting portion 22 around the rotation direction. In other words, the center of rotation CL of the cutting portion 22 and the center of gravity are offset in the radial direction.

[0042] A rotational driving force is applied from the driving unit 23 arranged on the inlet 4 side to the cutting unit 22 inserted into the piping 10 with the central axis of the flexible shaft 29 aligned with the central axis of the piping 10, and the rotational driving force causes the flexible shaft 29 to rotate about the central axis, and the flexible connecting part main body 54 arranged on the outlet 5 side rotates about the central axis of the flexible connecting part main body 54 with respect to the cutting unit 22, causing the cutting unit 22 to rotate about its rotation center together with the rotation of the flexible shaft 29 and the flexible connecting part main body 54. Then, the flexible shaft 29 and the flexible connecting part main body 54 are bent so that the central axis is curved by the centrifugal force of the rotation, and as a result, the cutting unit 22 rotates around the central axis of the piping 10 with its rotation center separated radially outward by the amount of bending of the flexible shaft 29 and the flexible connecting part main body 54 relative to the central axis (pipe axis) of the piping 10.

[0043] Moreover, the cutting part 22 has a central hole 42 formed in the base 38, the male thread of the rod-shaped member 37 screwed into the inlet 4 side, and the male thread of the one-side connector 43 screwed into the outlet 5 side. The cutting part 22 is configured to rotate in the rotational direction, and a blade tip 49 of the cutting part 22 protrudes from the base 38. When the cutting part 22 is rotated by the rotational driving force of the drive part 23, the pipe 10 can be cut into the inlet 4 side and the outlet 5 side at a predetermined position.

[0044] Then, the flexible shaft 29 and the flexible connection body 54 are bent by the rotational driving force of the drive unit 23, and the cutting unit 22 attached to the tip of the flexible shaft 29 is rotated and shifted radially outward by the amount of bending, so that it can be reliably brought into contact with the inside of the pipe 10, thereby reliably cutting the pipe 10. In the cutting blade cutting process, the cut pipe 10a, which is a predetermined portion on the inlet 4 side of the middle part of the pipe 10, is cut so that its length in the pipe axial direction is shorter than that of the remaining pipe 10b, which is the remaining middle part.

[0045] Meanwhile, pipe cutting device 20 includes a first support part 35 between drive part 23 and cutting part 22, which is configured to have a larger diameter than flexible shaft part 29 and is arranged in pipe 10 to be cut so as to support flexible shaft part 29. Pipe cutting device 20 also includes a second support part 53 arranged in pipe 10 to be cut so as to support flexible connection part main body 54.

[0046] Therefore, in the cutting blade cutting process, when the flexible shaft 29 and the flexible connection body 54 are rotated around the central axis, the first support portion 35 acts to support the flexible shaft 29, and the second support portion 53 acts to support the flexible connection body 54. For this reason, the first support portion 35 and the second support portion 53 serve as fulcrums for the bending of the flexible shaft 29 and the flexible connection body 54, so that the flexible shaft 29 and the flexible connection body 54 bend and rotate reliably, and the piping 10 can be cut.

[0047] The second support part 53 is made of a bearing jig, and the lid part 60 and the jig body 61 are connected by a bearing. The lid part 60 and the jig body 61 are configured to be relatively rotatable with respect to each other in the pipe axial direction, so that even if the flexible connection part body 54 rotates, no rotational force is applied to the rope body body 31. Even if the first support part 35 and the second support part 53 are held in position, the cutting part 22 is held by the flexible shaft part at the inlet 4 side and the outlet 5 side, so that it is sufficiently bent within the pipe 10, and the cutting part 22 rotates to cut the pipe 10 at a predetermined portion 10c (see FIG. 4). That is, the first support part 35 and the second support part 53 (jig body 61) are non-rotating with respect to the rotation of the flexible shaft part 29 and the flexible connection part body 54, and support the flexible shaft part 29 and the flexible connection part body 54 in a state of not rotating within the pipe 10. Further, the second support portion 53 is configured to isolate the rotation of the flexible shaft portion 29 and the flexible connection portion main body 54 from being transmitted to the rope body main body 31 .

[0048] Next, the (2-1E) piping removal step will be described. In the piping removal step, a removal means A for the piping 10 is used. Therefore, before describing the (2-1E) piping removal step, the removal means A for the piping 10 will be described.

[0049] The removal means A for the piping 10 is for removing the piping 10 inserted in the protective tube 9 from the protective tube 9 along the tube axial direction. The removal means A in this embodiment includes a pushing means B and a pulling means C.

[0050] The pushing means B is for pushing the pipe 10 from the other side to one side in the pipe axial direction. The pushing means B is composed of a contact means B1 and a moving means B2. The pushing means B in this embodiment is composed of a pipe cutting device 20.

[0051] The contact means B1 contacts the pipe end face on the other side in the pipe axis direction of the pipe 10. Therefore, the contact means B1 is disposed on the other side in the pipe axis direction than the pipe 10. Here, the contact means B1 in this embodiment is configured by one blade end face 47. In this embodiment, the pipe end face on the other side in the pipe axis direction of the cut pipe 10a has a shape cut by the cutting blade portion 39. Therefore, as shown in FIG. 4, the end face on the other side and one blade end face 47 contact each other without any gap.

[0052] The moving means B2 moves the abutment means B1 to one side in the tube axis direction. The moving means B2 in this embodiment is disposed to one side of the abutment means B1 in the tube axis direction, i.e., forward in the removal direction. Specifically, the moving means B2 in this embodiment is composed of a drive unit 23 (not shown in FIG. 4), a transmission shaft 24, and a base 38 connected by a support ring 36. The moving means B2 in this embodiment moves the one blade end face 47 to one side in the tube axis direction by pulling the drive unit 23 to one side in the tube axis direction.

[0053] The pulling means C is for pulling the pipe 10 to one side in the pipe axial direction on one side of the pipe end face on the other side in the pipe axial direction of the pipe 10. The pulling means C includes a holding means C1 and a pulling means C2.

[0054] The holding means C1 is for holding the pipe 10 on one side of the pipe end face on the other side in the pipe axis direction of the pipe 10. The holding means C1 in the inlet side removal process is the hand of an operator (not shown). That is, in this embodiment, the cut pipe 10a is held by the holding means C1 when the operator grasps with his hand the end portion on the inlet 4 side, which is the area of ​​the cut pipe 10a exposed from the protective tube 9 in the pipe axis direction.

[0055] The pulling means C2 pulls the holding means C1 to one side in the pipe axial direction. In the inlet removal step, the worker holds and pulls the pipe 10 by hand, so the worker himself is the pulling means C2.

[0056] (2-1E) In the pipe removal process, one blade end face 47 is brought into contact with the pipe end face on the other side in the pipe axis direction of the cut pipe 10a from the other side in the pipe axis direction (rear side in the removal direction). Also, the operator holds the one side of the end face on the other side in the pipe axis direction of the cut pipe 10a, in this embodiment, the area of ​​the cut pipe 10a exposed from the protective pipe 9. Then, the drive unit 23, the transmission shaft 24, and the base 38 configured as the moving means B2 are pulled to one side in the pipe axis direction (front side), and the operator holding the cut pipe 10a pulls it to one side in the pipe axis direction.

[0057] As a result, one blade end surface 47 pushes the pipe end face on the other side of the pipe axial direction of the cut pipe 10a from the back side to the front side, while the cut pipe 10a is pulled forward by the operator on one side of the pipe end face on the other side. Therefore, a pulling force is applied to the cut pipe 10a on one side in the pipe axial direction at two points, front and back in the pulling direction, making it easier for the cut pipe 10a to move to one side in the pipe axial direction. Thus, the cut pipe 10a can be pulled out from the protective pipe 9. This completes the (2-1) inlet side pulling process.

[0058] After the inlet side removal process, the outlet side removal process (2-2) is performed to remove the piping remaining in the protective tube 9. This outlet side removal process includes the remaining piping removal confirmation process (2-2A), the remaining piping cutting process (2-2B), the tool removal process (2-2F), and the piping removal process (2-2G).

[0059] In the outlet side removal step, first, a remaining pipe removal confirmation step (2-2A) is performed to confirm whether the remaining pipe 10b remaining in the protective pipe 9 can be removed from the protective pipe 9. If the remaining pipe 10b cannot be removed from the protective pipe 9 in this remaining pipe removal confirmation step, the remaining pipe 10b is divided into a plurality of cut pipes 10d and 10e in the pipe axis direction, and each cut pipe 10d and 10e is removed from the protective pipe 9. In the remaining pipe removal confirmation step of this embodiment, an attempt is made to remove the remaining pipe 10b from the protective pipe 9 from the outlet 5 side to confirm whether the remaining pipe 10b can be removed from the protective pipe 9. Then, as described above, the remaining pipe 10b cannot be removed from the protective pipe 9. Therefore, the remaining pipe 10b is cut in the pipe axis direction and separated into the cut pipes 10d and 10e.

[0060] After the remaining pipe removal confirmation step, a remaining pipe cutting step (2-2B) is performed to separate the remaining pipe 10b into a plurality of cut pipes 10d and 10e separated in the pipe axial direction. This remaining pipe cutting step is the same as the above-mentioned (2-1A) pipe cutting step. Therefore, like the pipe cutting step, the remaining pipe cutting step includes a (2-2C) insertion step, a (2-2D) arrangement step, and a (2-2E) cutting blade cutting step. Explanation of each of these steps is omitted. Note that the remaining pipe 10b remaining in the protective pipe 9 has an end 10c (see FIG. 4) that is the cutting position in the previous cutting blade cutting step arranged in the protective pipe 9, and the cutting part 22 is inserted into the remaining pipe 10b with this end as the inlet side end. Then, as shown in FIG. 5(a)(b), in this embodiment, the remaining pipe 10b is separated into the cut pipe 10e on the outlet 5 side and the cut pipe 10d remaining in the protective pipe 9 by the (2-1D) cutting blade cutting step.

[0061] 5(a) and 5(b), in the (2-2F) tool removal step, the transmission shaft 24, the cutting portion 22, and the preceding connecting portion 50 are removed. In this embodiment, the transmission shaft 24, the cutting portion 22, and the preceding connecting portion 50 are removed from the inlet 4 side with the cable body 31 inserted through the cutting pipes 10d and 10e.

[0062] The (2-2G) pipe removal process will be described. In the pipe removal process, the worker removes the cut pipe 10e from the outlet 5 side. Here, in the pipe removal process, the cut pipe 10e is removed from the protective pipe 9 using the removal means A. Specifically, in the (2-2G) pipe removal process in the (2-2) outlet side removal process, only the pulling means C is used as the removal means A. As described above, this pulling means C is composed of the worker's hand as the holding means C1 and the worker himself as the pulling means C2. That is, in the pipe removal process, the worker holds the cut pipe 10e with the outlet 5 side as one side in the pipe axis direction (the front side in the removal direction) and the inlet 4 side as the other side in the pipe axis direction (the rear side in the removal direction), and then pulls it forward, so that the cut pipe 10e is removed from the protective pipe 9 in the pipe axis direction. Therefore, as shown in FIG. 5(c), the cut pipe 10d with the entire area in the pipe axis direction covered remains in the protective pipe 9. This concludes the description of the (2-2) outlet side removal process.

[0063] 7 to 9, (2-3) the intermediate punching step will be described. In the intermediate punching step, the cut pipe 10d is pulled out from inside the protective pipe 9. Here, in the intermediate punching step, a punching means A is used. Therefore, before describing the intermediate punching step in detail, the punching means A will be described.

[0064] In this embodiment, the extracting means A used in the intermediate extracting process is configured to be different from the extracting means A used in the above-mentioned (2-1) inlet side extracting process and (2-2) outlet side extracting process. Specifically, the extracting means A used in the intermediate extracting process is a pipe extracting device. The pipe extracting device includes a pipe pulling device 7 that pulls the cut pipe 10d to one side in the pipe axial direction, and a pipe pushing device 8 that pushes the cut pipe 10d from the other side to one side in the pipe axial direction. The pipe pulling device 7 is the pulling means C, and the pipe pushing device 8 is the pushing means B. Note that in this embodiment, the pipe pulling device 7 and the pipe pushing device 8 are configured as separate entities.

[0065] 7, the pipe pulling device 7 includes a pulling tool 70 and a one-side pulling unit 7a that moves the pulling tool 70 to one side in the pipe axis direction. The pipe pulling device 7 of this embodiment includes a other-side pulling unit 7d that moves the pulling tool 70 to the other side in the pipe axis direction.

[0066] The pulling tool 70 connects the one pulling part 7a and the other pulling part 7d. As shown in Fig. 10, the pulling tool 70 includes a pulling body 71 that is inserted into the protective tube 9, and rope body support parts 701 and 702 that support the rope bodies 7b and 7e.

[0067] As shown in Fig. 10, the puller body 71 of this embodiment is formed with a rope insertion part 703 that penetrates in the axial direction (the direction in which the dashed line in Fig. 10 extends) and through which the rope 8b described below can be inserted. Therefore, the puller body 71 of this embodiment is cylindrical. The puller body 71 includes an insertion part 72 that can be inserted into the cutting pipe 10d, and a restriction part 73 that restricts the entire area of ​​the puller body 71 in the pipe axial direction from being inserted into the cutting pipe 10d.

[0068] The insertion portion 72 is configured to have a diameter smaller than the inner diameter of the cut pipe 10d in the radial direction. The outer periphery of the insertion portion 72 is circular. A hook portion 72a that abuts against the inner periphery of the cut pipe 10d is formed on the outer periphery of the insertion portion 72.

[0069] The hook portion 72a is configured so that it cannot bite into the cutting pipe 10d when the pulling tool 70 is inserted into the cutting pipe 10d, and can bite into the cutting pipe 10d when the pulling tool 70 is removed from the cutting pipe 10d. In this embodiment, the hook portion 72a bites into the inner peripheral surface of the cutting pipe 10d, so that the holding means C1 holds the cutting pipe 10d. Therefore, the hook portion 72a of this embodiment is configured as the holding means C1. In addition, the hook portion 72a of this embodiment is configured to have a shape that expands radially outward as it proceeds from the rear side to the front side in the removal direction. Specifically, the hook portion 72a is configured to expand radially outward beyond the inner diameter of the cutting pipe 10d. In addition, the hook portion 72a of this embodiment is configured so that it can be reduced in diameter in the radial direction and can be expanded in diameter to return to its original state in the radial direction. Therefore, in this embodiment, when the pulling tool 70 is inserted into the cutting pipe 10d from the side of the rope support part 702, the rear side of the hook part 72a in the pulling direction abuts against the inner peripheral surface of the cutting pipe 10d, and the hook part 72a contracts in the radial direction. On the other hand, when the pulling tool 70 is moved from the rear side to the front side in the pulling direction and pulled out from the cutting pipe 10d, the hook part 72a expands in the radial direction to return to its original state, and the hook part 72a bites into the cutting pipe 10d.

[0070] In this embodiment, a plurality of hook portions 72a are provided in the circumferential direction on the outer periphery of the insertion portion 72. Also, a plurality of hook portions 72a are provided in the axial direction of the insertion portion 72 (two in the axial direction in FIG. 10).

[0071] The restricting portion 73 is configured to be larger than the inner diameter of the cut pipe 10d. Therefore, as shown in Fig. 9, when the pulling body portion 71 is inserted into the cut pipe 10d from the side of the rope support portion 702, the contact surface 73a (see Fig. 10) contacts the pipe end surface of the cut pipe 10d. This prevents the pulling tool 70 inserted into the cut pipe 10d from one side in the pipe axis direction from moving inside the cut pipe 10d and coming out from the other side in the pipe axis direction.

[0072] The rope support parts 701, 702 are formed at both axial ends of the pull body 71. The rope support parts 701, 702 of this embodiment have through holes 701a, 702a penetrating in the radial direction, and are formed in a substantially U-shape. Therefore, as shown in FIG. 7, the rope support parts 701, 702 support the ropes 7b, 7e by passing the tip attachment parts 7c, 7f through the through holes 701a, 702a.

[0073] In addition, the rope support parts 701 and 702 of this embodiment are formed with rope insertion parts 701b and 702b that penetrate in the axial direction and through which the rope 8b is inserted. As shown in Fig. 10, the rope insertion parts 701b and 702b of this embodiment are formed with their centers shifted to one side in the radial direction from the central axis (the dashed line in Fig. 10).

[0074] In the intermediate removal process, the one-side pulling unit 7a is configured as a pulling means C2. The one-side pulling unit 7a includes a rope 7b and a winch (not shown) that pulls the rope 7b. In this embodiment, the tip attachment unit 7c passes through the through-hole 701a, and the rope 7b is supported by the rope support unit 701. Then, the winch pulls the rope 7b to one side in the pipe axis direction, whereby the one-side pulling unit 7a moves the pulling tool 70 to one side in the pipe axis direction.

[0075] The other pulling section 7d includes a rope 7e and a winch (not shown) that pulls the rope 7e to the other side in the pipe axial direction. In this embodiment, the tip attachment section 7f is passed through the through hole 702a, so that the rope 7e is supported by the rope support section 702. The rope 7e is passed through a rope insertion section 803 described later.

[0076] 7, the pipe pushing device 8 includes a pushing tool 80 and a one-side pulling unit 8a that moves the pushing tool 80 to one side in the pipe axial direction. The pipe pushing device 8 of this embodiment includes an other-side pulling unit 8d that moves the pushing tool 80 to the other side in the pipe axial direction.

[0077] 11, the pushing tool 80 connects the one pulling part 8a and the other pulling part 8d. The pushing tool 80 includes a pushing main body 81 that is inserted into the protective tube 9, and rope body support parts 801 and 802 that support the rope bodies 8b and 8e.

[0078] As shown in Fig. 11, the pushing body 81 of this embodiment is formed with a rope insertion portion 803 that penetrates in the axial direction (the direction in which the dashed line in Fig. 11 extends) and through which the rope 7e can be inserted. Therefore, the pushing body 81 of this embodiment is configured in a cylindrical shape. The pushing body 81 includes an insertion portion 82 that can be inserted into the cutting pipe 10d, and a restriction portion 83 that restricts the entire area of ​​the pushing body 81 in the axial direction from being inserted into the cutting pipe 10d. The insertion portion 82 is configured to be smaller in the radial direction than the inner diameter of the cutting pipe 10d. The outer periphery of the insertion portion 82 is circular.

[0079] The restricting portion 83 is configured to be larger than the inner diameter of the pipe 10d to be cut in the radial direction. Therefore, for example, when the pushing body 81 is inserted into the pipe 10d to be cut from the side of the cord support portion 801, the contact surface 83a contacts the pipe end surface of the pipe 10d to be cut. Therefore, in the pipe pushing device 8, the contact surface 83a is configured as the contact means B1.

[0080] The rope body support parts 801, 802 are formed at both ends of the pushing body 81 in the axial direction. The rope body support parts 801, 802 of this embodiment have through holes 801a, 802a penetrating in the radial direction, and are formed in a substantially U-shape. Therefore, as shown in FIG. 7, the rope body support parts 801, 802 support the rope bodies 8b, 8e by passing the tip attachment parts 8c, 8f through the through holes 801a, 802a. In addition, the rope body support parts 801, 802 of this embodiment are formed with rope body insertion parts 801b, 802b penetrating in the axial direction and for inserting the rope body 7e. Note that, as shown in FIG. 11, the rope body insertion parts 801b, 802b of this embodiment are formed with their centers shifted to one side in the radial direction from the central axis (the dashed line shown in FIG. 11).

[0081] In the intermediate removal process, the one-side pulling unit 8a is configured as a moving means B2. The one-side pulling unit 8a includes a rope 8b and a winch (not shown) that pulls the rope 8b. In this embodiment, the tip attachment unit 8c passes through a through hole 801a, and the rope 8b is supported by the rope support unit 801. Then, the winch pulls the rope 8b to one side in the pipe axis direction, whereby the one-side pulling unit 8a moves the pulling tool 80 to one side in the pipe axis direction.

[0082] The other pulling section 8d includes a rope 8e and a winch (not shown) that pulls the rope 8e to the other side in the pipe axial direction. In this embodiment, the tip attachment section 8f is passed through the through hole 802a, so that the rope 8e is supported by the rope support section 802. The rope 8e is passed through the rope insertion section 703.

[0083] The (2-3) intermediate removal process includes (2-3A) an insertion process, (2-3B) an arrangement process, and (2-3E) a piping removal process.

[0084] As shown in Fig. 7, in the (2-3A) insertion step, the ropes 8b and 7e are passed through the cutting pipe 10d. Here, in the insertion step of this embodiment, the pulling tool 70 is arranged so that the rope support part 702 faces inside the protective pipe 9, and the rope 8b inserted through the rope insertion part 703 and the rope insertion parts 701b and 702b is inserted through the cutting pipe 10d from the entrance 4 to the exit 5. Also, the pushing tool 80 is arranged so that the rope support part 801 faces inside the protective pipe 9, and the rope 7e inserted through the rope insertion part 803 and the rope insertion parts 801b and 802b is inserted through the cutting pipe 10d from the exit 5 to the entrance 4. Then, on one side in the tube axis direction, the tip mounting portions 7c, 7f are passed through the through holes 701a, 702a to support the rope bodies 7b, 7e on the rope body support portions 701, 702, thereby connecting the one towing portion 7a and the other towing portion 7d to the pulling tool 70, and on the other side in the tube axis direction, the tip mounting portions 8c, 8f are passed through the through holes 801a, 802a to support the rope bodies 8b, 8e on the rope body support portions 801, 802, thereby connecting the one towing portion 8a and the other towing portion 8d to the pushing tool 80.

[0085] The (2-3B) arranging step is a step of arranging the extraction means A on both ends of the cut pipe 10d. The arranging step of this embodiment includes the (2-3C) other side arranging step using the pipe pushing device 8 which is the pushing means B, and the (2-3D) one side arranging step using the pipe pulling device 7 which is the pulling means C.

[0086] As shown in FIG. 8(a), in the (2-3C) other side arrangement step, the abutment means B1 is abutted against the pipe end face on the other side in the pipe axis direction of the cut pipe 10d. In the other side arrangement step of this embodiment, in the one pulling section 8a, the rope body 8b is pulled to one side in the pipe axis direction by the winch, so that the pushing tool 80 moves from the other side in the pipe axis direction to one side while being guided by the rope body 7e, and is inserted into the protective pipe 9. Then, the pushing tool 80 moves inside the protective pipe 9, and the insertion part 82 is inserted into the cut pipe 10d from the other side in the pipe axis direction. In addition, the abutment surface 83a, which is the abutment means B1, abuts against the pipe end face on the other side in the pipe axis direction of the cut pipe 10d. Note that the abutment surface 83a abuts against the pipe end face on the other side in the pipe axis direction of the cut pipe 10d, and the movement of the pushing tool 80 to one side in the pipe axis direction is stopped.

[0087] As shown in Fig. 8(b), in the (2-3D) one-side arrangement step, the hooking part 72a is inserted into the cut pipe 10d from one side in the pipe axis direction. In the one-side arrangement step of this embodiment, in the other-side pulling part 7d, the rope body 7e is pulled to the other side in the pipe axis direction by a winch, so that the pulling tool 70 moves from one side in the pipe axis direction to the other side while being guided by the rope body 8b, and is inserted into the protective pipe 9. Then, the pulling tool 70 moves inside the protective pipe 9, and the insertion part 72 is inserted into the cut pipe 10d from one side in the pipe axis direction, and the abutment surface 73a abuts against the pipe end face on one side in the pipe axis direction of the cut pipe 10d, thereby stopping the movement of the pulling tool 70 to the other side in the pipe axis direction.

[0088] Here, when the insertion portion 72 is inserted into the cut pipe 10d, the hook portion 72a abuts against the inner peripheral surface of the cut pipe 10d. Therefore, as the insertion portion 72 advances inside the cut pipe 10d from the front side to the rear side in the removal direction, the hook portion 72a is reduced in diameter. Therefore, in the one-side arrangement step of this embodiment, the hook portion 72a abuts against the inner peripheral surface of the cut pipe 10d without biting into the cut pipe 10d when inserted into the cut pipe 10d.

[0089] As shown in FIG. 9, in the (2-3D) pipe removal step, the pulling means C2 and the moving means B2 move the holding means C1 and the abutting means B1 to one side in the pipe axis direction. In the one-way pulling parts 7a and 8a of this embodiment, the winch pulls the ropes 7b and 8b to one side in the pipe axis direction (the direction of the arrow shown in FIG. 9) at the same time. As a result, in the pipe pulling device 7, the pulling tool 70 moves to one side in the pipe axis direction (the front side in the pulling direction). At that time, the hooking part 72a abutting the inner peripheral surface of the cut pipe 10d expands in diameter to return to its original shape in the radial direction and bites into the inner peripheral surface of the cut pipe 10d. Therefore, while the holding means C1 holds the cut pipe 10d, the pulling means C2 pulls the holding means C1 to one side in the pipe axis direction.

[0090] On the other hand, in the pipe pushing device 8, by pulling the cord body 8b to one side in the pipe axis direction, the pushing tool 80 moves to one side in the pipe axis direction while the abutment surface 83a as the abutment means B1 pushes the pipe end face on the other side in the pipe axis direction of the cut pipe 10d to one side. Therefore, the cut pipe 10d can be moved to one side in the pipe axis direction and removed from the protective pipe 9.

[0091] As described above, the pipe pulling method according to this embodiment is as follows: That is, this embodiment is a pipe pulling method for pulling, in a pipe axial direction, a pipe 10 whose at least a middle portion in the pipe axial direction is covered, and includes a pulling step of pulling the pipe 10 to one side in the pipe axial direction with one end of the pipe 10 in the pipe axial direction being the front and the other end being the rear, and the pulling step is a step of pushing a pipe end face of the other end of the pipe 10 to one side, and pulling the pipe 10 to one side in the pipe axial direction by holding and pulling the pipe 10 on the one side of the pipe axial direction relative to the pipe end face of the other end of the pipe 10.

[0092] According to the above-mentioned construction method, in the pulling process, the pipe end face of the other end of the piping 10 is pushed to one side, and the pipe 10 is held and pulled on one side in the pipe axis direction relative to the pipe end face of the other end of the piping 10, thereby preventing the piping 10 from breaking in the pipe axis direction when the piping 10 is pulled to one side in the pipe axis direction.

[0093] Therefore, according to this embodiment, the pipe end face of the other end of the piping 10 is pushed to one side, and one side of the pipe end face of the other end of the piping 10 in the pipe axial direction is held and pulled to remove the piping 10 to one side in the pipe axial direction, so that the piping 10 can be removed reliably.

[0094] In addition, in the pulling tool 70 of this embodiment, the centers of the rope body insertion parts 801b, 802b are formed to be shifted to one side in the radial direction from the axis. Therefore, in the (2-3A) insertion step, when the one pulling part 7a and the other pulling part 7d are connected to the pulling tool 70, interference between the rope bodies 7b, 7e and the rope body 8b can be reduced. The same is true for the pushing tool 80.

[0095] In the (2-3C) other side arrangement step of this embodiment, the abutment surface 83a was abutted against the pipe end face on the other side in the pipe axis direction of the cut pipe 10d using the pipe pushing device 8, which is the pushing means B. On the other hand, in the (2-3D) one side arrangement step, the hook portion 72a was inserted into the cut pipe 10d using the pipe pulling device 7, which is the pulling means C. That is, as shown in Figures 8(a) and 8(b), in the (2-3B) arrangement step of this embodiment, the pipe pulling device 7 and the pipe pushing device 8, which are independent from each other, were used on one side and the other side in the pipe axis direction, so that the pipe removing device, which is the removing means A, can be applied without considering the length of the pipe 10 in the pipe axis direction.

[0096] In addition, in the (2-3E) pipe removal step of this embodiment, on the pulling means C side, the pulling means C2 moves the holding means C1 to one side in the pipe axial direction, and on the pushing means B side, the moving means B2 moves the abutting means B1 to one side in the pipe axial direction. Therefore, since the means for moving the holding means C1 and the abutting means B1 are separate, the load on the pipe removal device when the cut pipe 10d is removed from the protective pipe 9 can be distributed between the pipe pulling device 7 and the pipe pushing device 8.

[0097] In the (2-3C) other-side arranging step and (2-3D) one-side arranging step of this embodiment, the pushing tool 80 and the pulling tool 70 are inserted into the protective tube 9 while being guided by the cord bodies 7e and 8b, respectively. Therefore, the pushing tool 80 and the pulling tool 70 can be easily inserted into the protective tube 9.

[0098] Next, the insertion process (3) will be described. In the insertion process, new piping is inserted inside protective pipe 9. In the insertion process, first, a cord-like call wire is inserted into protective pipe 9 in advance, and a cord body (not shown) is pulled and inserted from the exit to the entrance of protective pipe 9 by the call wire, and a piping insertion tool (not shown) is attached to the cord body body exposed from the entrance 4 side. Here, the piping insertion tool is configured so that it can be inserted into protective pipe 9. Then, after the piping insertion tool is attached to the cord body body at the entrance 4 side, the piping insertion tool is attached to the tip of the new piping and fixed.

[0099] After the pipe insertion tool is fixed to the tip of the new pipe, the rope body is pulled from the outlet 5 by driving the winch, and the tip of the new pipe is moved from the inlet 4 to the outlet 5. When the tip of the new pipe is exposed from the outlet 5, the insertion process is completed. With the above process, the pipe renewal of this embodiment is completed.

[0100] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. Furthermore, the specific configurations of the respective parts are not limited to the above-described embodiment.

[0101] In the above embodiment, the case where the pipe 10 is disposed inside the protective pipe 9 has been described, but the present invention is not limited to this, and the pipe removal method of the present invention can be adopted even when the pipe 10 is fixed in a predetermined place, such as when the pipe 10 is buried in the ground or concrete, or when the pipe 10 is fixed to a wall or floor. Incidentally, including this case, the insertion step in the above embodiment may be unnecessary.

[0102] The pipe extraction method of the present invention has been described as an extraction process in which the pipe is extracted using a pulling means and a pushing means, but it can also be considered as an extraction method in which the extraction process in which the pipe is extracted using a pulling means and a pushing means, the extraction process in which the pipe is extracted using only the pulling means, and the push process in which the pipe is extracted using only the pushing means are selected according to the installation situation of the pipe. Specifically, it is possible to consider an extraction method in which the pipe is extracted by selecting the extraction process, the pulling process, and the push process without cutting the pipe in the circumferential direction, or an extraction method in which the pipe is cut so as to be separated into multiple pieces in the pipe axial direction and the extraction process, the pulling process, the pulling process, and the push process are selected for each of the cut pipes. According to the above method, for example, the manner in which the pipe is extracted from the protective pipe can be flexibly changed according to the situation of the pipe at each site. Note that the above change may also include, for example, a case in which the process is changed before the pipe is completely extracted from the protective pipe.

[0103] The (2-1C) arranging step in the above embodiment is performed by arranging the cutting portion 22 at the predetermined position 10c inside the pipe 10, but is not limited thereto, and may be a case where the cutting portion 22 is arranged at the predetermined position 10c outside the pipe 10. As such a case, for example, a case where a pipe 10 that is covered at two or more places in the pipe axial direction is cut can be considered.

[0104] In the above embodiment, the pipe 10 is cut in the circumferential direction and separated into cut pipes 10a, 10d, and 10e, and each of the cut pipes is pulled out of the protective pipe 9 in the pipe axial direction in separate steps, namely, an inlet side pulling step, an outlet side pulling step, and an intermediate pulling step. However, the present invention is not limited to this, and for example, the pipe 10 may be pulled out of the protective pipe 9 without cutting the pipe 10 in the circumferential direction and separating it. In this case, since the pipe 10 is not cut, the process can be simplified and the burden on the worker can be reduced. In addition, the form of the pipe 10 pulled out of the protective pipe 9 may be, for example, the pipe 10 whose inner circumferential surface is cut in order to remove dust attached to the inner circumferential surface of the pipe 10.

[0105] In the above embodiment, as the (2-2) outlet side removal step, the (2-2A) remaining pipe removal confirmation step is performed to confirm that the remaining pipe 10b cannot be removed from the protective pipe 9, and then the (2-2B) remaining pipe cutting step is performed. However, for example, if the (2-2A) remaining pipe removal confirmation step determines that the remaining pipe 10b can be removed from the protective pipe 9, the remaining pipe 10b can be removed from the protective pipe 9, and the subsequent (2-2B) remaining pipe cutting step and (2-3) intermediate removal step may not be performed. In this case, the remaining pipe 10b may be removed from either the inlet 4 side or the outlet 5 side.

[0106] In the above embodiment (2-2G) piping removal process, a case has been described in which only the pulling means C is used as the removal means A, but this is not limited thereto. For example, only the pushing means B may be used as the removal means A, or a combination of the pulling means C and the pushing means B may be used.

[0107] In the above embodiment, the pulling means C2 and the moving means B2 are configured so that the ropes 7b and 8b are pulled by the respective winches, and the one-side pulling parts 7a and 8a move the holding means C1 and the abutting means B1, respectively. However, for example, the holding means C1 and the abutting means B1 may be moved to one side in the pipe axial direction by one pulling means. In this case, one pulling means serves as the pulling means C2 and the moving means B2.

[0108] In the above embodiment, by pulling the rope body 7b with the winch, the pulling tool 70 moves to one side in the pipe axis direction, the hooking portion 72a expands in diameter and bites into the inner peripheral surface of the cut pipe 10d, and while the holding means C1 holds the cut pipe 10d, the pulling means C2 pulls the holding means C1 to one side in the pipe axis direction. However, with regard to moving the holding means C1 to one side in the pipe axis direction, for example, in addition to or instead of pulling the holding means C1 to one side in the pipe axis direction with the pulling means C2, it is considered to move the holding means C1 to one side in the pipe axis direction by pushing the holding means C1 from the other side in the pipe axis direction to one side in the pipe axis direction (from the rear side to the front side in the pull-out direction).

[0109] In the above embodiment, the pipe pulling device 7 is configured to include the other-side pulling portion 7d, but this is not limiting, and the pipe pulling device 7 may not include the other-side pulling portion 7d. In this case, the pulling tool 70 may not include the rope body support portion 702, and the pushing tool 80 may not include the rope body insertion portion 803 and the rope body insertion portions 801b and 802b. Also, in the (2-3A) insertion step, it is not necessary to insert the rope body 7e from the outlet 5 to the inlet 4. Also, the pipe pushing device 8 may not include the other-side pulling portion 8d.

[0110] In the above embodiment, a case has been described in which a plurality of hook portions 72a are provided on the outer periphery of the insertion portion 72 in the circumferential direction, but the present invention is not limited to this and may be such that only one hook portion is provided on the outer periphery of the insertion portion 72 in the circumferential direction. Also, in the above embodiment, a case has been described in which two hook portions 72a are provided in the axial direction of the insertion portion 72, but the present invention is not limited to this and may be such that the number of hook portions provided in the axial direction is increased or decreased.

[0111] In the above embodiment, the pulling body 71 is configured to have the restricting portion 73, but this is not limiting, and for example, the pulling body 71 does not need to have the restricting portion 73. That is, the hook portion 72a configured as the holding means C1 may hold the cutting pipe 10d by biting into the cutting pipe 10d on one side in the pipe axial direction of the pipe end face on the other side in the pipe axial direction of the cutting pipe 10d.

[0112] In the above embodiment, the cable body insertion portions 701b, 702b, 801b, and 802b are described as being formed with their centers shifted radially to one side from the central axis, but this is not limited thereto, and for example, they may be configured so that the central axis passes through the center.

[0113] In the above embodiment, the case where the cut pipes 10a, 10d, and 10e formed by cutting the pipe 10 in the pipe axis direction are pulled out has been described, but the present invention is not limited to this, and the pipe 10 may be pulled out in a state where it is cut in the radial direction. In this case, for example, the pipe 10 may be pulled out from one side in the pipe axis direction while cutting the pipe 10 in the radial direction with a cutting jig that cuts the pipe 10 in the radial direction.

[0114] In the above embodiment, the (1) preparation step is provided separately from the (2) punching step. However, for example, the preparation step may be a step included in the punching step.

[0115] In the above embodiment, the (2-3C) other-side arranging step is performed and then the (2-3D) one-side arranging step is performed. However, this is not limiting, and the one-side arranging step may be performed after the one-side arranging step.

[0116] In the above embodiment, as shown in Fig. 10, the pulling tool 70 has the rope body inserting parts 701b, 702b and the rope body inserting part 703 to pass the rope body 8b, but is not limited thereto, and for example, as shown in Fig. 12, the pulling tool 70 does not need to have the rope body inserting parts 701b, 702b and the rope body inserting part 703. The same applies to the pushing tool 80.

[0117] In the above embodiment, when the hook portion 72a is inserted into the pipe 10d to be cut, the hook portion 72a contracts inwardly by contacting the inner peripheral surface of the pipe 10d to be cut, and is pulled from the rear side to the front side in the pull-out direction to expand in the radial direction to return to its original size, so that the hook portion 72a bites into the pipe 10d to be cut. However, the present invention is not limited to this. For example, as shown in Figs. 13 and 14, after the puller 70 is inserted into the pipe 10, the hook portion 72a housed in the insertion portion 72 may expand in diameter to bite into the inner peripheral surface of the pipe 10. Here, in Figs. 13(a) and (b), the puller 70 extends in the axial direction (left and right direction in Fig. 13) inside the pipe 10, so that the hook portion 72a housed in the insertion portion 72 in advance protrudes in the radially outward direction and bites into the pipe 10. 14(a) and 14(b), after the pulling tool 70 is inserted into the pipe 10, the hook portion 72a stored in advance in the insertion portion 72 protrudes radially outward and abuts against the inner peripheral surface of the pipe 10. Then, the pulling tool 70 is pulled from the rear side to the front side in the removal direction, so that the hook portion 72a bites into the inner peripheral surface of the pipe 10.

[0118] In the above embodiment, the hooking portion is configured to abut against the inner peripheral surface of the pipe, so that the pulling tool holds the pipe. However, the present invention is not limited to this, and the hooking portion may be configured to bite into the pipe in the radial direction. In this case, as shown in Figs. 13 and 14, the hooking portion formed on the insertion portion may be configured to stand in the radially outward direction within the pipe. Specifically, the pulling tool shown in Fig. 13 is configured to expand and contract in the pipe axial direction, and as shown in Fig. 13(a), when the insertion portion is inserted into the pipe, the pulling tool extends in the pipe axial direction, so that the hooking portion stored in the insertion portion moves in the radially outward direction and bites into the pipe. On the other hand, in the pulling tool shown in Fig. 14, after the insertion portion is inserted into the pipe as shown in Fig. 14(a), the hooking portion provided on the outer peripheral surface of the insertion portion stands in the radially outward direction and abuts against the inner peripheral surface of the pipe as shown in Fig. 14(b).

[0119] In the above embodiment, as shown in Fig. 7 to 10, the hook portion 72a is configured to hold the pipe 10 while abutting against the inner peripheral surface of the pipe 10, but the present invention is not limited thereto, and for example, as shown in Fig. 15, the hook portion may be configured to hold the pipe by forming a spiral protrusion, which bites into the inner peripheral surface of the pipe. In this case, when inserting the insertion portion 72 into the pipe 10, for example, it is considered that the hook portion 72a forms a spiral groove in the pipe 10 by inserting the insertion portion 72 into the pipe 10 while rotating the pulling tool 70 about the pipe axis direction by the driving unit.

[0120] In the above embodiment, the pushing tool 80 is configured as shown in FIG. 11, but the present invention is not limited thereto. For example, the pushing tool 80 may be configured as shown in FIG. 16. That is, the inserting portion 82 may be configured to be inserted into the pipe. In this case, the pushing tool 80 is configured to be longer than the pipe in the pipe axial direction. Therefore, the pipe can be prevented from being broken over the entire pipe axial direction. In addition, in the pushing tool shown in FIG. 16, the inserting portion 82 is configured to be shorter in the radial direction as it moves from the front side to the back side. Therefore, the inserting portion 82 is easily inserted into the pipe. In addition, in the pushing tool 80 shown in FIG. 16, the rope body 8b is inserted into the inserting portion 82, so that the rope body support portion 801 supports the rope body 8b. The rope body support portion 802 may support the rope body by inserting the rope body 8e into it. [Explanation of symbols]

[0121] 1...existing pipe, 4...inlet, 5...outlet, 9...protective pipe, 10...pipe, 10a...cut pipe, 10b...remaining pipe, 11...new pipe, 19...shaft, 19A...connecting rod portion, 20...pipe cutting device, 22...cutting portion, 23...driving portion, 24...transmission shaft, 25...leading portion, 27...driving connecting shaft portion, 28...multiple shaft portion, 29...flexible shaft portion, 31...rod body, 35...first support portion, 37...rod shaped member, 38...base, 39...cutting blade part, 42...center hole, 43...one connecting body, 46...trailing side surface, 47...one blade end surface, 49...blade tip, 50...leading connecting part, 51...rope body, 52...flexible link Connection part, 53... Second support part, 54... Flexible connection part main body, 55... Other connection body, 56, 56... Annular member, 56A... Easily flexible part, 57... Center rod, 60... Lid part, 61... Jig main body, 62... Connection body

Claims

[Claim 1] A method for removing a pipe in an axial direction of the pipe, the method comprising the steps of: a cutting blade cutting process in which the pipe is cut midway in the pipe axis direction using a cutting part having a cutting blade to separate the pipe into a cut pipe and a remaining pipe; and a pulling process in which the cut pipe and the remaining pipe are pulled to one side in the pipe axis direction with one end of the cut pipe and the other end of the remaining pipe being the front and the rear, The punching step includes: a step of bringing the cutting blade into contact with a pipe end surface of the other end of the cut pipe, pressing the pipe end surface of the other end to one side with the cutting blade, and pulling the cut pipe to one side in the pipe axial direction by holding one side of the pipe end surface of the other end of the cut pipe in the pipe axial direction; a step of pushing a pipe end face of the other end of the remaining pipe to one side, and causing a pulling tool having a hook portion that is configured to be unable to bite into the remaining pipe when moving from the front side to the rear side of the remaining pipe and to bite into the remaining pipe when moving from the rear side to the front side of the remaining pipe to bite into one side of the pipe end face of the other end of the remaining pipe, and pulling the remaining pipe via the pulling tool, thereby pulling the remaining pipe to one side in the pipe axial direction.

Images