Removal method of cutting device

Abstract

To provide a removal method of a cutting device which enables the cutting device to be removed with a cut piece by using a crane with a low lifting capacity.SOLUTION: A cutting device includes: a cutter 52 having a center drill 52b and a cylindrical member 52a for engaging with a cut piece 1a to hold it; a lid body installed at an opening 2b of a housing 2; a drive mechanism for driving the cutter 52; and holding means 9 provided at the housing 2 below the lid body. A removal method of the cutting device comprises: a closing step in which the cut piece 1a and the cutter 52 are moved to the opening 2b side of the housing 2 relative to a work valve 4 which may open or close the housing 2, and then the work valve 4 is closed; a holding step in which the cutter 52 and the cut piece 1a are held by the holding means 9; a drive mechanism removal step in which the drive mechanism disconnected from the cutter 52 is removed by using a crane; a lid body removal step in which the lid body disconnected from the housing 2 is removed by using the crane leaving the cutter 52 and the cut piece 1a held by the holding means 9; and a cutter removal step in which the cutter 52 is removed from the cut piece 1 and the housing 2 by using the crane.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a removal method for removing, in a non-stop flow state, a cutting device that cuts a part of a fluid pipe from a housing attached to the fluid pipe.

Background Art

[0002] For fluid pipes constituting existing pipelines through which water, gas, etc. flow, in order to address aging deterioration or form new branch paths, a part of the existing fluid pipe may be changed to a new fluid pipe, or an aging pipeline may be blocked. In such cases, a part of the fluid pipe may be cut using a cutting device.

[0003] As a method of cutting a fluid pipe in this way, a method of cutting a fluid pipe in a non-stop flow state is known. In such a method, a housing that is attached to the pipe wall of the existing fluid pipe in a sealed manner, a working valve that can open and close the inside of the housing, and a cutting device that is attached to the opening of the housing in a sealed manner are used. This cutting device is mainly composed of a cutter for cutting the fluid pipe, a lid that can seal and close the opening of the housing, and a drive mechanism for moving the cutter forward and backward and rotating it.

[0004] When cutting a fluid pipe using a cutting device composed of these members, with the cutter disposed inside the housing, the opening of the housing is closed with the lid, the cutter that rotates by the drive mechanism is advanced toward the fluid pipe to cut the fluid pipe, and after the cutter is retracted above the working valve together with the cut piece by the drive mechanism, the inside of the housing is closed with the working valve, so that a non-stop flow state can be maintained over a series of steps.

[0005] Such a cutting device is generally suspended by a crane and attached to the installation position inside the housing. Particularly when the diameter of the fluid pipe is large, the structure of the cutting device also becomes large and the weight increases, so in order to transport the cutting device in an integrally assembled state, it is necessary to prepare a large crane with a high lifting capacity. Therefore, a large space is required for the arrangement and operation of the crane.

[0006] Therefore, in the installation of the cutting device shown in Patent Document 1, for example, when using a crane to hang a lid for closing the upper part of the housing together with the cutter, after the lid is attached to the housing in a sealed manner, the same crane is used to hang the drive mechanism in a separate process, and the cutting device is assembled by connecting the drive mechanism, the cutter, and the lid. Thereby, the lifting capacity required for the crane can be reduced.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] In the installation of the cutting device of Patent Document 1 as described above, since it is possible to attach the cutting device to the housing using a crane with a low lifting capacity, the work valve can be attached even in a working environment where a large space cannot be secured.

[0009] On the other hand, when removing the cutting device from the housing after cutting the fluid pipe, in a process opposite to the installation of the cutting device, that is, the drive mechanism and the lid holding the cutter are separated and removed from the housing. However, since the cutter after cutting holds the section of the fluid pipe and thus has an increased weight, especially as the diameter of the fluid pipe or the cut portion of the fluid pipe becomes larger, the weight increases, so there is a risk of exceeding the lifting capacity of the crane used during the installation of the cutting device. Therefore, it was necessary to prepare a crane with a high lifting capacity in anticipation of the weight of the section.

[0010] The present invention has been made paying attention to such problems, and an object thereof is to provide a method for removing a cutting device that can be removed together with a section using a crane with a low lifting capacity.

Means for Solving the Problem

[0011] In order to solve the above problems, a method for removing the cutting device of the present invention is a removal method in which, inside a housing attached to a fluid pipe, after cutting the fluid pipe, the cutting device is removed using a crane together with a section cut from the fluid pipe in a non-stop flow state, the cutting device includes at least a cutter for holding the section, a lid installed at an opening of the housing, and a drive mechanism for driving the cutter, a closing step of moving the cutter together with the section to a side of the opening of the housing rather than a service valve that can be opened and closed inside the housing, and then closing the service valve, a drive mechanism removal step of removing the drive mechanism whose connection with the cutter has been released using the crane, a lid removal step of removing the lid whose connection with the housing has been released using the crane, and a cutter removal step of removing the cutter together with the section from the housing using the crane, and is characterized by comprising these steps. According to this feature, by removing the lid whose connection with the housing has been released prior to removing the cutter, the load on the crane when removing the cutter together with the section can be reduced. As a result, the cutting device can be removed together with the section using a crane with a low lifting capacity used during installation.

[0012] The cutting device further includes holding means for holding the cutter that has been moved to a side of the opening of the housing rather than the service valve, and is characterized by performing a holding step of holding the cutter by the holding means between the closing step and the lid removal step. According to this feature, since the cutter can be held by the housing by the holder, the lid can be removed.

[0013] The holding means includes a holder provided so as to be movable in a radial direction with respect to the housing, In the holding step, the holder is advanced inward of the housing to hold the cutter. According to this feature, the operation for holding the cutter can be performed from the outside.

[0014] The lid body includes moving means for moving the drive mechanism together with the cutter in a direction away from the fluid pipe. In the holding step, after moving the cutter together with the drive mechanism in a direction away from the fluid pipe by the moving means, the holder is advanced inward of the housing. According to this feature, the work of holding the cutter by the holder can be easily performed.

[0015] In the cutter removal step, a suspended means for connecting the crane to the cutter is provided. According to this feature, the crane can be easily connected to the cutter.

[0016] In the cutter removal step, the crane is connected to a plurality of the suspended means provided at equally spaced positions in the circumferential direction of the cutter. According to this feature, it is easy to achieve weight balance when the cutter is suspended by the crane.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0018] The embodiments for carrying out the method for removing the cutting device according to the present invention will be described below based on examples.

Examples

[0019] In the examples, a series of processes from cutting a predetermined portion of the existing fluid pipe 1 constituting the flow path component by the cutting machine 5 as the cutting device to removing the cutting machine 5 in a non-stop flow state will be described with reference to FIGS. 1 to 12.

[0020] As shown in Fig. 1, the surroundings of a predetermined location of the fluid pipe 1 buried in the ground are excavated, and a housing 2 having a two-part structure with a branch portion 2a opening upward is hermetically surrounded. Note that the fluid in the fluid pipe 1 may be, for example, tap water, industrial water, sewage, etc., or may also be gas or a gas-liquid mixture of gas and liquid. Furthermore, although the housing 2 has a two-part structure in this embodiment, it may have other multi-part structures, and the joining of the divided housings may be performed by welding or by attaching with bolts via packing.

[0021] The fluid pipe 1 is a steel pipe and is formed in a substantially circular cross-sectional shape. Note that the fluid pipe according to the present invention may be made of other metals such as cast iron or ductile cast iron, or may be made of concrete, vinyl chloride, polyethylene, polyolefin, etc. Furthermore, the inner peripheral surface of the fluid pipe may be coated with an epoxy resin layer, mortar, plating, etc., or the inner peripheral surface of the fluid pipe may be coated with an appropriate material by powder coating.

[0022] Also, when attaching the housing 2 to the fluid pipe 1, a concrete foundation (not shown) is formed below the housing 2 to support the weight around the housing 2 and prevent the fluid pipe 1 from bending or the like. Note that as long as it can support the weight of the housing 2 and the cutting machine 5, it is not limited to a concrete foundation, and a jack or the like may be used.

[0023] Also, a packing (not shown) is press-fitted in the circumferential direction between the pipe wall of the fluid pipe 1 and the housing 2, so that the sealing performance between the fluid pipe 1 and the housing 2 can be ensured. Note that the packing may be press-fitted into a concave groove provided on the housing 2 side or may be press-fitted into a concave groove provided on the fluid pipe 1 side.

[0024] In addition, the housing 2 is provided with a working valve 4 capable of closing the opening of the branch portion 2a. The working valve 4 mainly includes a substantially cylindrical valve box 41 hermetically connected above the branch portion 2a, a valve body 42 that can be seated on a valve seat 41a of the valve box 41, a valve cover 43 hermetically connected to the valve box 41 and capable of accommodating the valve body 42, and a valve rod 44 that connects the valve body 42 to the valve cover 43 so as to be movable forward and backward. By rotating the valve rod 44 forward and backward, the valve body 42 can be advanced toward the valve box 41 side and seated on the valve seat of the valve box 41 to close the inside of the housing 2, or the valve body 42 can be retracted toward the valve cover 43 side to open the inside of the housing 2.

[0025] In addition, the housing 2 is provided with a substantially cylindrical mounting flange cylinder 21 hermetically connected above the valve box 41. An opening 2b opened upward is formed at the upper end of the mounting flange cylinder 21.

[0026] Next, a process of installing a cutting machine 5 for cutting the fluid pipe 1 above the mounting flange cylinder 21 will be described. As shown in FIG. 2, first, a cutter 52 and a lid body 53 are temporarily installed on the mounting flange cylinder 21. Specifically, the cutter 52 and the lid body 53 of the mounting flange cylinder 21 connected above it are together suspended by a hoisting tool C and a wire W provided with a hook suspended by a crane (not shown), and lowered above the mounting flange cylinder 21.

[0027] The crane used in this embodiment is preferably a mobile rough terrain crane, and needless to say, it will be enlarged according to its lifting capacity. In addition, the installation area of the crane often requires a larger area than the excavation area of the fluid pipe 1 when including outriggers and the like. The selection of the rough terrain crane to be used is based on the presence or absence of a lifting capacity capable of lifting the member with the largest weight among the respective members, the allowable lifting load at the turning radius, and the like.

[0028] The cutter 52 comprises a cylindrical member 52a having a cutting edge at its peripheral end, and a center drill 52b coaxially disposed on the cylindrical member 52a and protruding beyond the perforating blade. The cylindrical member 52a and the center drill 52b are fixed. Also, above the cylindrical member 52a and the center drill 52b, an adapter 54 having an annular protrusion 54a formed at its upper end is mounted in a non-rotatable relative manner.

[0029] The lid body 53 has a through hole 53a penetrating vertically at its center, and the adapter 54 is inserted through the through hole 53a. Further, the lid body 53 has a plurality of recesses 53b recessed in the outer diameter direction from the inner peripheral surface of the through hole 53a in the circumferential direction, and a fixing jig 55 that can advance and retreat in the radial direction of the through hole 53a is disposed in the recesses 53b. When the fixing jig 55 protrudes in the inner diameter direction of the through hole 53a and engages with the lower surface of the annular protrusion 54a of the adapter 54, the cutter 52 and the lid body 53 are detachably connected. Also, on the upper surface of the lid body 53, a plurality of jacks 7 (moving means) that can expand and contract in the vertical direction are fixed on the outer diameter side of the through hole 53a.

[0030] Next, as shown in FIG. 3, the lid body 53 is placed above the mounting flange cylinder 21, and in this state, the mounting flange cylinder 21 and the lid body 53 are aligned and fixed with bolts and nuts (not shown). Thereby, the opening 2b of the mounting flange cylinder 21 constituting the housing 2 is sealed, and the cutter 52 is accommodated inside the mounting flange cylinder 21. <S

[0031] Also, since a packing (not shown) is pressed against the circumferential direction between the opening 2b of the mounting flange cylinder 21 and the lid body 53, the sealing performance between the mounting flange cylinder 21 and the lid body 53 can be ensured. Note that the packing may be press-fitted into a concave groove provided on the lid body 53 side, or may be press-fitted into a concave groove provided on the mounting flange cylinder 21 side.

[0032] Next, the drive mechanism 8 of the cutting machine 5 is connected to the cutter 52. First, the structure of the drive mechanism 8 will be described.

[0033] As shown in FIG. 3, the drive mechanism 8 mainly includes a shaft member 81, a gripping member 82 capable of gripping or releasing the shaft member 81, a reciprocating member 83 that reciprocates the gripping member 82 within the axial range of the shaft member 81, a restricting member 84 capable of restricting or releasing the movement of the shaft member 81 at a position below the reciprocating member 83, and a base member 85 to which the reciprocating member 83 and the restricting member 84 are attached.

[0034] The base member 85 is provided with a plurality of upright support columns. The reciprocating member 83 is attached to be slidable in the vertical direction along the support columns. That is, by gripping the shaft member 81 with the gripping member 82 and moving the reciprocating member 83 along the support columns in this state, the shaft member 81 can be slid in the vertical direction.

[0035] Below the base member 85, a cylindrical case portion 86 through which the shaft member 81 can be inserted is provided. An extension piece portion 86a extending in a substantially horizontal direction is formed at the lower end edge of the case portion 86.

[0036] A rotary motor 87 is fixed to a part of the reciprocating member 83. By applying a rotational force to the gripping member 82 gripping the shaft member 81 by the rotary motor 87, rotation can be transmitted to the shaft member 81, and when the shaft member 81 rotates, the cutter 52 can be rotated. Note that by preparing a plurality of shaft members 81, the axial length can be increased by adding them axially. Due to such an adding structure, the weight and height can be reduced.

[0037] When connecting the drive mechanism 8 configured as described above to the cutter 52, referring to FIG. 4, the shaft member 81 is advanced downward by a predetermined length in advance so that the lower end portion of the shaft member 81 protrudes below the case portion 86. The drive mechanism 8 is suspended by the hanger C and the wire W, and the extension piece portion 86a of the case portion 86 is fixed to the upper end of a rod extending upward from the base of the jack 7.

[0038] Next, an operator accesses through the gap between the case portion 86 and the upper flange 53c of the lid body 53, and connects the shaft member 81 and the adapter 54 with bolts and nuts. Then, the fixing jig 55 is retracted into the recess 53b. Here, the extending piece portion 86a is not necessarily required. For example, a support mechanism may be placed between the upper flange 53c and the drive mechanism 8. Alternatively, it may be placed on the ground instead of the upper flange 53c.

[0039] Subsequently, as shown in FIG. 4, a rod is housed in the base of the jack 7, the case portion 86 is placed on the upper flange 53c of the lid body 53, and the case portion 86 and the lid body 53 are fixed with bolts and nuts (not shown). As a result, since the cutter 5 is constituted by the cutter 52, the lid body 53, the adapter 54, and the drive mechanism 8, the load applied to the crane in a single lifting can be reduced as compared with the case of transporting the cutter 5 integrally. Thereby, the cutter 5 can be installed in the housing 2 using a small crane with a low lifting capacity. At this time, it goes without saying that the center drill 52b is adjusted so as not to contact the valve body 42 when closed (see FIG. 6).

[0040] In addition, in this embodiment, the form in which the drive mechanism 8 is lowered by the jack 7 is illustrated. However, in order to enhance safety, the drive mechanism 8 may be lowered by the jack 7 while being gently suspended by the sling C and the wire W. By doing so, the load on the crane can be reduced, and the load on the crane can be alleviated. Further, the drive mechanism 8 may be lowered by the crane without using the jack 7.

[0041] Also, when the case portion 86 and the lid body 53 are fixed, a packing (not shown) is pressed between the case portion 86 and the upper flange 53c of the lid body 53, so that the sealing performance between the case portion 86 and the lid body 53 can be ensured. Note that the packing may be press-fitted into an annular groove formed on the lower surface of the case portion 86, or may be press-fitted into an annular groove provided on the upper flange 53c side of the lid body 53.

[0042] Next, as shown in FIG. 5, with the valve body 42 of the working valve 4 retracted into the valve cover 43 and the branch portion 2a opened, the drive mechanism 8 is operated to cut the fluid pipe 1 in a non-stop flow state while advancing the cutter 52. At this time, by connecting another shaft member 81' to the shaft member 81, the distance by which the cutter 52 is moved can be appropriately adjusted.

[0043] In addition, a recess 2e is formed at the bottom of the housing 2 so as to be recessed downward. When the fluid pipe 1 is cut by the cutter 52, the center drill 52b protruding below the lower end of the cylindrical member 52a is accommodated in the recess 2e in a spaced-apart state. Therefore, it is possible to prevent the center drill 52b from accidentally damaging the housing 2.

[0044] Furthermore, a valve (not shown) is attached to the bottom of the recess 2e. By opening this valve, the chips generated when the fluid pipe 1 is cut by the cutter 52 can be discharged to the outside together with the fluid through the drain.

[0045] Here, as shown in FIG. 6, a retainer 52g is provided at the tip of the center drill 52b, which can expand in the outer diameter direction of the center drill 52b and is used to lock and hold the section 1a of the fluid pipe 1 described later. This retainer 52g is housed on the inner diameter side rather than the outer peripheral surface of the center drill 52b as shown by the dotted line in the blown-out view of FIG. 6 while the center drill 52b is piercing the pipe wall of the fluid pipe 1. When it penetrates the pipe wall, it expands to the outer diameter side rather than the outer peripheral surface of the center drill 52b as shown by the solid line in the blown-out view of FIG. 6. Thereby, the section 1a of the fluid pipe 1 cut by the cutter 52 is locked by the retainer 52g and held inside the cylindrical member 52a.

[0046] Next, the method of removing the cutting machine 5 will be described. The removal of the cutting machine 5 is performed in the order of the closing process, the holding process, the drive mechanism removal process, the cover removal process, and the cutter removal process.

[0047] First, as shown in FIG. 6, an occlusion process is performed. In this process, the drive mechanism 8 is operated to pull up the cutter 52 together with the chip 1a and retract it into the mounting flange cylinder 21 above the position where the valve body 42 of the working valve 4 can move. Then, the valve rod 44 is rotated forward to advance the valve body 42 into the valve box 41 to make the inside of the housing 2 in an occluded state.

[0048] Next, as shown in FIG. 7, a holding process is performed. In this process, first, the bolt nut that fixes the case portion 86 of the drive mechanism 8 and the upper flange 53c of the lid body 53 is removed, the jack 7 is extended, and the drive mechanism 8 and the cutter 52 are moved upward together.

[0049] Here, a plurality of recesses 21a recessed in the outer diameter direction from the inner peripheral surface are formed in the circumferential direction on the peripheral wall of the mounting flange cylinder 21. As shown in the blowout of FIG. 7, a holder 90 that can advance and retreat in the radial direction of the mounting flange cylinder 21 is disposed in the recess 21a. The holder 90 is prevented from rotating by the inner peripheral surface of the recess 21a. Further, a spindle 91 is rotatably supported at the outer diameter end of the recess 21a. A male screw that is screwed into the female screw hole of the holder 90 is formed on the spindle 91.

[0050] Thereby, by rotating the operation portion of the spindle 91 that is open to the outside of the mounting flange cylinder 21 forward and backward, the holder 90 advances to the inner diameter side of the mounting flange cylinder 21, or the holder 90 retreats into the recess 21a. That is, the mounting flange cylinder 21, the holder 90, and the spindle 91, which are part of the housing 2, constitute the holding means 9 of the present invention.

[0051] Further, an annular flange 52c protruding to the outer diameter side is formed at the upper end of the cylindrical member 52a of the cutter 52. Note that the flange 52c may be formed at the upper end portion 52d (see FIG. 10) of the cutter 52 described later, and the formation location and shape may be appropriately changed as long as the cutter 52 can be held. For example, instead of being annular, it may be a protrusion shape adapted to the position of the holder 90.

[0052] Return to the description of the holding process. Rotate the spindle 91 clockwise from the outside of the mounting flange cylinder 21 to advance the holder 90 to the inner diameter side of the mounting flange cylinder 21 and lock it to the lower surface of the flange 52c of the cutter 52, thereby holding the cutter 52 in the housing 2. At this time, since the cutter 52 has been moved by the jack 7 as described above, the cutter 52 can be easily held by the holder 90. Further, due to the flange 52c of the cutter 52, the holder 90 can easily lock the cutter 52.

[0053] Next, as shown in FIGS. 7 and 8, perform the drive mechanism removal process. In this process, remove the bolt nut connecting the shaft member 81 and the adapter 54 to release these connections. Note that even after these connections are released, the loads of the cutter 52 and the chip 1a are held in the housing 2 by the holder 90. Subsequently, also release the fixation between the rod of the jack 7 and the extended piece portion 86a of the case portion 86. And although not shown directly, lift and remove the drive mechanism 8 with the hoist C and the wire W (see FIG. 8).

[0054] Next, as shown in FIGS. 8 and 9, perform the cover removal process. In this process, remove the bolt nut fixing the mounting flange cylinder 21 and the cover 53, and lift and remove the cover 53 with the hoist C and the wire W (see FIG. 9).

[0055] Next, as shown in FIGS. 10 and 11, perform the cutter removal process. In this process, as shown in FIG. 10, first attach the shackle S to the four female screw holes 52e formed equidistantly in the circumferential direction at the upper end portion 52d of the cutter 52. At this time, since the cutter 52 is held near the opening 2b which is the upper end of the housing 2, it is easy to attach the shackle S.

[0056] Then, connect the wire W to the shackle S, and lift and remove the cutter 52 together with the chip 1a by the lifting tool C and the wire W (see Fig. 11). At this time, since the female screw holes 52e are equally spaced in the circumferential direction of the cutter 52 at four positions, it is easy to achieve a weight balance when suspending the cutter 52. As a result, the cutter 52 and the chip 1a can be safely removed without tilting. In this way, the female screw holes 52e and the shackle S constitute the means to be suspended in this embodiment. Note that the female screw holes 52e are not limited to being equally spaced at four positions, and may be equally spaced at two or more positions, or may not be equally spaced, and the number and arrangement may be changed as appropriate. Also, the mounting position of the shackle S may be appropriately selected from among a plurality (for example, ten locations) of the female screw holes 52e.

[0057] In addition, at the upper end portion 52d of the cutter 52, as shown in Fig. 12, since six equally spaced communication holes 52f for discharging the fluid when cutting the fluid pipe 1 are provided, the lifting tool C may be locked to the lifting belt B inserted through a pair of adjacent communication holes 52f, 52f, and the cutter 52 may be lifted and removed together with the chip 1a by the lifting tool C and the belt B. That is, the upper end portion 52d of the cutter 52 having the communication holes 52f is also a means to be suspended.

[0058] Also, although not shown directly, by using the shackle S, the wire W, and the belt B in combination, the load acting on them may be dispersed.

[0059] In this way, while maintaining a non-stop flow state, the fluid pipe 1 can be cut, the cutting machine 5 can be removed from the housing 2, and the chip 1a can be recovered.

[0060] As described above, in the method for removing the cutting machine 5 of this embodiment, by removing the lid 53 whose connection to the housing 2 has been released prior to removing the cutter 52, the load on the crane when removing the cutter 52 together with the chip 1a can be reduced. As a result, the cutting machine 5 can be removed together with the chip 1a using a small crane with a lifting capacity kept low during installation.

[0061] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments, and even if there are changes or additions within the scope not departing from the gist of the present invention, they are included in the present invention.

[0062] For example, in the above embodiment, the cutting machine 5 having the cutter 52 which is a hole saw as the cutting device has been described as an example. However, it is not limited thereto, and the cutting device may be a drilling machine, as long as it can cut at least a part of the peripheral wall of the fluid pipe 1.

[0063] Also, although the holding means 9 has been described as being constituted by the mounting flange cylinder 21, the holder 90, and the spindle 91, it is not limited thereto. For example, the holding means may be such that the holder 90 and the spindle 91 are provided on the valve box 41 of the working valve 4 or a lid body having a cylindrical portion, or the cutter 52 may be placed on the valve body 42 of the working valve 4, and it may be appropriately changed.

[0064] Also, although the holder 90 has been described as being configured to move in the radial direction in accordance with the rotation of the spindle 91, it is not limited thereto. For example, it may be a bolt screwed into the peripheral wall of the mounting flange cylinder 21, or may be configured to move in the radial direction by a jack, and may be appropriately changed.

[0065] Also, although the lid body 53 has been described as being configured such that the jack 7 is fixed thereto, it is not limited thereto, and it may be detachably provided.

Explanation of Reference Numerals

[0066] 1 Fluid pipe 1a Section 2 Housing 2b Opening 4 Working valve 5 Cutting machine (cutting device) 7 Jack (moving means) 8 Driving mechanism 9 Holding means 52 Cutter 52d Upper end portion (suspended means) 52e Female screw hole (suspended means) 53 Cover 90 Holder 91 Spindle S Shackle (suspended means)

Claims

1. A removal method for removing a cutting device using a crane together with a section cut from a fluid pipe in a state of continuous flow after cutting the fluid pipe inside a housing attached to the fluid pipe, comprising: The cutting device includes at least a cutter having a center drill and a cylindrical member for locking and holding the section, a lid installed at an opening of the housing, a drive mechanism for driving the cutter, and holding means provided in the housing below the lid. A closing step of closing the working valve after moving the cutter together with the section to a side of the opening of the housing rather than the working valve that can be opened and closed inside the housing; A holding step of holding the cutter and the section by the holding means; A drive mechanism removal step of removing the drive mechanism whose connection to the cutter has been released using the crane; A lid removal step of removing the lid whose connection to the housing has been released using the crane, leaving the cutter and the section held by the holding means; A cutter removal step of removing the cutter together with the section from the housing using the crane, characterized in that it consists of the above steps. A method for removing a cutting device.

2. The method for removing a cutting device according to claim 1, characterized in that in the cutter removal step, a suspended means for connecting the crane to the cutter is provided.

3. The method for removing a cutting device according to claim 2, characterized in that in the cutter removal step, the crane is connected to a plurality of the suspended means provided at equally distributed positions in the circumferential direction of the cutter.

4. The method for removing a cutting device according to claim 2 or 3, characterized in that the suspended means includes a female screw hole formed in the cutter and a shackle attached to the female screw hole.

5. The method for removing a cutting device according to claim 2 or 3, characterized in that the suspended means includes a communication hole for discharging fluid formed at an upper end portion of the cutter.

Images