JPH11304074A - Existing pipe cutting method and water supply nonfailure valve insertion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an existing pipe cutting method capable of shortening cutting time and with no trouble of damaging a rubber packing provided on a rotational sliding part. SOLUTION: An existing pipe 1 is cut in a roughly annular shape by a disc type cutter 130 by surrounding the existing pipe 1 by aclosed case divided into a plural number of pieces in the peripheral direction R of the existing pipe 1 in an airtight state, installing a cutter 3 having a disc type cutter 130 to cut the existing pipe 1 in the closed case 2A by rotating around a cutter shaft 133 in parallel with a pipe shaft of the existing pipe 1 on the closed case 2A, delivering the disc type cutter 130 in the radial direction C of the existing pipe 1 while rotating the disc type cutter 130 around the cutter shaft 133 and rotating the disc type cutter 130 along an outer periphery of the existing pipe 1 with the closed case 2A by rotating the closed case 2A around the existing pipe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting an existing pipe and a method for inserting a valve without interruption.

[0002]

2. Description of the Related Art Conventionally, there is a well-known method of inserting a valve into an existing pipe by cutting an existing pipe with water without interruption and inserting a valve into a pipe at the cut point (for example, US Pat. No. 5,611,3).
No. 65 and JP-A-4-194491). FIG.
In the method of inserting a non-water valve shown in FIG. 3, the existing pipe 1 is surrounded and bent by a sealed case 500, and a cutting tool 502 is fixed to a tip of a gate valve 501 attached to the sealed case 500. 501
Is rotated, and the existing pipe 1 is cut by the cutting tool 502. According to this conventional technique, since the cutting tool 502 is rotated along the outer circumference of the existing pipe 1 by rotating the closed case 500, a mechanism for rotating the cutting tool 502 along the outer circumference of the existing pipe 1 is provided as a mechanism. It is not necessary to provide inside. Therefore, the size of the sealed case 500 is reduced.

[0003]

However, in this conventional cutting method, the existing pipe 1 is cut with the tip-shaped cutting tool 502. Therefore, when cutting the existing pipe 1 made of a cast iron pipe or a steel pipe, the sealed case 500 is cut. Has to be rotated many times, it takes a long time to cut, and the rubber packing for sealing between the sealed case 500 and the existing pipe 1 may be damaged. Therefore, the present invention has been made to solve such a conventional problem.

[0004]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, an existing pipe cutting method according to the present invention is characterized in that an existing pipe is hermetically sealed by a closed case divided into a plurality of pieces in a circumferential direction of the existing pipe. Attaching a cutting machine having a disk-shaped cutter for cutting the existing pipe in the closed case while rotating around the cutter axis parallel to the pipe axis of the existing pipe while attaching to the closed case, While rotating the cutter around the cutter axis, the disc-shaped cutter is sent in the radial direction of the existing pipe, and a part or all of the sealed case is rotated around the existing pipe so that the disc-shaped cutter together with the sealed case can be connected to the existing pipe. And the existing pipe is cut into a substantially annular shape by a disk-shaped cutter. The term "sealed" in the present invention does not mean completely closed. Therefore, the "sealed case" has a pressure resistance to withstand the pressure of a fluid (water or the like) flowing in an existing pipe and a certain degree of water stoppage. A thing.

According to the present invention, since the cutting is performed by rotating the cutting tool around the cutter axis, the existing pipe can be cut by rotating the sealed case once. Therefore, the cutting time can be shortened, and there is no possibility that the rubber packing provided on the rotary sliding portion is damaged.

In the present invention, if the disc-shaped cutter is a non-directional cutter capable of cutting in any rotational direction, even if the rotational direction of the cutter is mistaken in the field,
Can be cut.

If a cutter made of a diamond wheel is used, such a diamond wheel has a small thickness, so that the portion to be cut and removed is reduced, so that the cutting time can be further shortened and the power for rotating the sealed case is reduced. be able to.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a method for cutting an existing pipe and a method for inserting an undischarged water valve according to the present invention.

[0009] As shown in the cutting apparatus Figure 2, in this embodiment, a first closed casing 2A of the central pair of left and right second closed casing 2B.
As shown in FIG. 1, the first closed case 2A is divided into first and second divided cases 121, 12 divided in the circumferential direction.
2 and a cutter mounting case 123. In addition,
The second sealed case 2B (FIG. 2) is also divided into two in the circumferential direction. As shown in FIG. 3, each of these cases 121,
A rubber ring 124 and the like are used to seal between the first and second casings 122, 2A and 2B and between the second sealed case 2B and the existing pipe 1. The second split case 122 has a branch portion 122b that protrudes outward in the pipe radial direction in a branch shape. The cutter mounting case 123 is connected to the branch portion 122b via a guide bush 122a. It is mounted so that it can slide in the radial direction and move forward and backward. An opening 122c into which two disk-shaped cutters (cutting tools) 130 enter is formed in the branched portion 122b of the second split case 122.

The cutter 3 is mounted on the cutter mounting case 123 of the first closed case 2A. That is, a first motor 131 for rotating the tool is fixed above the cutter mounting case 123, while two disc-shaped cutters (cutting tools) 130 are arranged in the cutter mounting case 123. Has been established. These disc-shaped cutters 130 are arranged apart from each other in the pipe axis direction S, and are rotatably supported by a bearing case 132 fixed to a cutter mounting case 123.
33. The first motor 131 has a first motor
The disc-shaped cutter 130 is rotated via an output shaft of the motor 131 and a bevel gear 134 fixed to the cutter shaft 133.

As the disk-shaped cutter 130, a known diamond wheel or metal saw can be used. The diamond wheel has diamond particles on both sides of at least the outer peripheral portion of the disk,
The existing pipe 1 can be cut by rotating in any one of the two rotation directions around the cutter shaft 133. The space between the bearing case 132 and the cutter shaft 133 is sealed by a mechanical seal (not shown).

A cut feed frame 136 is fixed to the branch portion 122b. The cut feed frame 136 is screwed with a cut feed male screw 137. The cut feed male screw 137 is rotated and screwed in the cut direction C (toward the center of the existing pipe). The cutter mounting case 123 advances in the cutting direction C. Therefore, while rotating the disc-shaped cutter 130, the cutter mounting case 123 is sent in the cutting direction C to open the disc-shaped cutter 130 into the opening 122c.
The existing pipe 1 can be cut by the disk-shaped cutter 130 as shown in FIG.
Note that the guide bush 122a is connected to the stay 1 in FIG.
It is fixed to the cut-and-feed frame 136 via 38 and can be collected together with the cut-and-feed frame 136 after cutting.

As shown in FIG. 1, a lifting belt 11A is wound around the existing pipe 1 and the cutter shaft 133, so that the section 10 (FIG. 5) can be collected together with the cutting machine 3 after the existing pipe 1 is cut. It has become. The lifting belt 11A is composed of an elastic rubber plate 11a and a thin metal belt 1.
1b and the joining piece 11c are joined.

In this embodiment, a case rotating device 4 shown in FIG. 2 for rotating the first closed case 2A around the existing pipe 1 is provided. The case rotation device 4 has a pair of second motors 142 for rotating the case. The second motor 142
Rotates the drive gear 144 for case rotation. The drive gear 144 rotates a case rotation driven gear 145 fixed to the first sealed case 2A. Therefore, FIG.
By rotating the first sealed case 2A around the existing pipe 1 once while rotating the disc-shaped cutter 130 in the cutting state, the existing pipe 1 can be cut at two places.

As shown in FIG. 3, each of the pair of second sealed cases 2B constitutes a deviation preventing device 5A. The second sealed case 2B is divided into two in the circumferential direction of the existing pipe 1, and the second sealed case 2B is
A large number of setscrews 151 are provided at two locations apart from each other in the circumferential direction. The first closed case 2A and the second closed case 2B have a rotation guide portion 150 that slides via a liner 152 in the tube axis direction S and the radial direction with respect to each other. The second closed case 2B is fixed to the existing pipe 1 by a set screw 151, and the first closed case 2A is guided by a pair of second closed cases 2B so that the first closed case 2A is a pipe of the existing pipe 1. Prevent axial displacement and blurring. Therefore, the first sealed case 2A smoothly rotates when rotating around the existing pipe 1. Note that a ball bearing or the like may be used instead of the liner 152.

[0016] The cutting process Next, a description is given of the procedure of cutting. First, with the fluid (water) flowing in the existing pipe 1 of FIG. 1, the upper half of the first and second sealed cases 2A and 2B is put on the existing pipe 1 and the lifting belt 11A is connected to the cutter shaft 133. And it winds around the existing pipe 1. Thereafter, the lower halves of the first and second sealed cases 2A and 2B and the upper halves are assembled with bolts 12
8 to fasten. Thus, as shown in FIG.
Is bent in an airtight state by the first and second sealed cases 2A and 2B. In addition, the cutting machine 3 is a first closed case 2A.
Is attached to the cutter mounting case 123 in advance. Next, while rotating the first motor 131 in FIG. 3 to rotate the disc-shaped cutter 130 at a high speed, the cutting feed male screw 137 is screwed in the cutting direction C, as shown by the two-dot chain line in FIG. The cutting is completed by feeding the disc-shaped cutter 130 to a position where the outer peripheral portion of the disc-shaped cutter 130 circumscribes the inner circumference of the existing pipe 1.

After this cutting, when the second motor 142 for rotating the case shown in FIG. 2 is driven, the first sealed case 2A is driven via a pair of drive gears 144 and the driven gear 145 shown in FIG.
Rotates around the existing pipe 1 while being guided by the second sealed case 2B. As a result, the disc-shaped cutter 130 rotates around the cutter shaft 133 while rotating along the outer circumference of the existing pipe 1 together with the first sealed case 2A, and cuts the existing pipe 1 into a substantially annular shape at two places. After the cutting, the case rotating device 4 is removed. The cutter mounting case 123
A drain valve may be attached to the drainage valve, and the chips at the time of cutting may be discharged from the drain valve.

Step of removing section Next, the cutting machine 3 and the section 10 are cut by the method described below.
Take out. That is, as shown in FIG.
The work gate valve 173 is joined to b, and the work upper tank 174 is further overlapped and joined to the work gate valve 173.
At the time of this joining, the cut-and-feed frame 136 is joined to the tip of the elevating shaft 176 that penetrates the upper work tank 174. After this joining, the nut 139 is removed, and after the removal, the lifting shaft 176 of FIG. 6 is pulled up to take out the cutting machine 3 and the section 10 from the first closed case 2A into the upper working tank 174, and then the working gate valve 173 is closed. After the valve is closed, the upper work tank 174 is separated from the work gate valve 173.

The valve insertion step Next, the valve cover 8b and the partition valve body 8a in FIG. 7 is accommodated in the working upper tank 174, joining the working upper tank 174 in the working sluice valve 173. The gate valve 8A includes a spindle 8c that opens and closes the gate valve body 8a. By rotating the spindle 8c, the gate valve body 8a enters the cut-off portion 12B, and a seal packing 8d provided on the gate valve body 8a. Constitutes a valve that presses against the inner peripheral surface of the first sealed case 2A in FIG.

After the work upper tank 174 shown in FIG. 7 is attached, the work partition valve 173 is opened as shown in FIG. 8, the elevating shaft 176 is lowered, and the valve lid 8b is connected to the branch portion 12 as shown in FIG.
2b, and the valve cover 8b and the branch portion 122b are joined by the flange bolt 8e. After this joining, the upper tank for operation 174 and the gate valve for operation 173 are removed. Thereafter, the packing insertion portion 16 of the second sealed case 2B of FIG.
In addition, the rubber ring 164 is pushed into the second closed case 2B while the rubber ring 164 is pushed into the second closed case 2B. Thus, the gate valve 8A is arranged at a position corresponding to the cut-off portion 12B, and the gate valve 8A is inserted into the pipeline.

FIGS. 10 to 12 show modified examples. As shown in this modification, the lifting belt 11A is
b. Further, as shown in FIG. 11, the output of the first motor 131 may be transmitted to the cutter shaft 133 via the timing belt 135. In addition, a guide roller 146 that cuts into the outer surface of the existing pipe 1 and guides the cutting machine 3 at the time of cutting shown in FIG. 12 may be provided. The cutter shaft 133 is rotatably supported by the eye bolt 133A.

Although not shown in the above description,
Obviously, there are additional or modified embodiments that are explicitly included in the spirit and scope of the invention. That is, the foregoing description and drawings are for the purpose of illustration only, and the scope of the present invention is limited only by the claims.

For example, in the above embodiment, the sealed case is divided into the first sealed case 2A and the second sealed case 2B, and a part of the sealed case, that is, the first sealed case 2A
However, in the present invention, the first closed case 2A and the second closed case 2B may be formed integrally. In this case, a deviation preventing device is separately provided beside the sealed case, and the whole sealed case is rotated. In the above-described embodiment, the first sealed case 2A and the cutting machine 3 are rotated around the existing pipe 1 by using the case rotating device 4 having the second motor 142 for rotating the case shown in FIG. In the present invention, as a method of rotating the closed case, a winch or heavy equipment (civil engineering and construction equipment) may be used, or the closed case may be rotated manually. Further, in the method of inserting a continuous water valve, a butterfly valve may be inserted instead of the gate valve.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a sealed case showing an embodiment of an existing pipe cutting method of the present invention.

FIG. 2 is a longitudinal sectional view showing the whole of a sealed case, a cutting machine, and the like.

FIG. 3 is a longitudinal sectional view mainly showing a cutting machine before cutting.

FIG. 4 is a longitudinal sectional view after the cutting.

FIG. 5 is a longitudinal sectional view showing a state where the work upper tank is assembled after cutting.

FIG. 6 is a cross-sectional view showing a state where a section is removed.

FIG. 7 is a cross-sectional view showing a state where the valve is housed in an upper tank.

FIG. 8 is a sectional view when a valve is inserted.

FIG. 9 is a sectional view showing a completed state.

FIG. 10 is a cross-sectional view of a main part showing a modification.

FIG. 11 is a sectional view taken along line XI-XI.

FIG. 12 is a cross-sectional view of a modified example after cutting.

FIG. 13 is a sectional view showing a conventional cutting method.

[Explanation of symbols]

 1: Existing pipe 10: Section 2A: First sealed case 2B: Second sealed case 3: Cutting machine 122b: Branch 123: Cutter mounting case 130: Disc-shaped cutter C: Cutting direction R: Circumferential direction S: Pipe Axial direction

Claims (7)

[Claims] 1. An existing pipe is hermetically surrounded and bent by a sealed case divided into a plurality of pieces in a circumferential direction of the existing pipe, and is rotated around a cutter axis parallel to a pipe axis of the existing pipe, Attaching a cutting machine having a disc-shaped cutter for cutting the existing pipe in the closed case to the closed case, and rotating the disc-shaped cutter around the cutter axis while attaching the disc-shaped cutter to the existing pipe. While sending in the radial direction, the disk-shaped cutter is rotated along the outer circumference of the existing pipe together with the closed case by rotating a part or all of the closed case around the existing pipe, and the existing pipe is disc-shaped. An existing pipe cutting method that cuts into a substantially annular shape using a circular cutter. 2. The sealed case according to claim 1, wherein the disc-shaped cutter is rotated in the sealed case in a state where the disc-shaped cutter is sent to a position so as to circumscribe the inner circumference of the existing pipe. An existing pipe cutting method for cutting the existing pipe by rotating the disc-shaped cutter in the circumferential direction of the existing pipe by rotating the cutter around the existing pipe. 3. The cutter mounting case according to claim 1, further comprising a cutter mounting case rotatably supporting the cutter shaft, wherein one of the divided cases in which the closed case is divided into a plurality of pieces is provided in a radial direction of an existing pipe. An existing pipe cutting method in which a branched part protruding in a branched shape is formed, and the cutter mounting case is attached to the branched part so as to be able to advance and retreat in the radial direction of the existing pipe, and the sealed case is formed. . 4. The existing pipe cutting device according to claim 1, wherein the disc-shaped cutter is a non-directional cutter capable of cutting the existing pipe regardless of any one of two rotation directions around the cutter axis. Construction method. 5. The existing pipe cutting method according to claim 1, wherein the disk-shaped cutter comprises a diamond wheel having diamond particles at least on both side surfaces of an outer peripheral portion of the disk. 6. The existing pipe cutting method according to claim 1, wherein the two disc-shaped cutters are fixed to the cutter shaft in a state of being separated from each other in a pipe axis direction. 7. After taking out the section cut out by the two disk-shaped cutters of claim 6 together with the disk-shaped cutter from the closed case, a valve for stopping a water pipe at a position corresponding to the section is inserted. Continuous water valve insertion method.