JP3571574B2 - Continuous cutting method for existing fluid pipes - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for cutting an existing fluid pipe, such as a water pipe or a gas pipe, which can be cut without interrupting the flow of an internal fluid.
[0002]
[Prior art]
Fluid pipes buried in the ground are often subjected to stress in the direction perpendicular to the pipes or in the pipe axis direction due to relative displacement of the ground due to earthquakes, land subsidence, etc., and when the stress exceeds the allowable limit. In such a case, the pipe may come off from the joint portion or a breakage accident may occur.
[0003]
In order to prevent such an accident, it is effective to attach a flexible joint to an existing fluid pipe.
As a conventional method of attaching the pipe joint without stopping the flow of the fluid in the fluid pipe, there is, for example, the following method.
[0004]
That is, a sealed case is water-tightly mounted around the fluid pipe, and the fluid pipe is cut into a ring shape by a cutting machine in the case. Is inserted into the closed case, fitted into the cut portion of the fluid pipe, and finally the inside of the closed case is removed from the fluid pipe.
[0005]
[Problems to be solved by the invention]
In the above-mentioned conventional method for expanding and contracting a fluid pipe, since it is necessary to attach a sealed case to the fluid pipe or to remove it after the work is completed, the work is complicated and the pipe diameter is large. Requires the use of a heavy machine such as a crane, which requires a large amount of work, leading to an increase in man-hours and work costs.
[0006]
In addition, a cutting machine equipped with a cylindrical cutter having a larger outer diameter is used for cutting the flow tube body. Therefore, when the pipe diameter is large, the cutting machine is inevitably increased in size, and its mounting and Removal work becomes complicated.
[0007]
The present invention has been made to solve the above problems, and can be cut easily and inexpensively into a fluid pipe without using a sealed case or a large cutting machine that needs to be removed after the work is completed. It is an object of the present invention to provide a method of continuously cutting water from an existing fluid pipe, which can be made to have expansion and contraction and flexibility by a part.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method for continuously cutting water of an existing fluid pipe, comprising preparing at least two cylindrical housings having at least two upper and lower divided structures having a working branch pipe , and connecting these housings to each other. After being attached to the outer peripheral surface of the existing fluid pipe in a water-tight manner and rotatable around the pipe axis at a predetermined distance, the feeding means is coaxial with the center of the branch pipe while rotating the housing by the rotation driving means. By rotating an end mill that penetrates a cylindrical seal provided on a base plate at the lower end so as to be slidable and rotatable up and down, and feeding the end mill toward a center direction of the existing fluid pipe by a feeding means , the existing fluid pipe is formed. After cutting, the end mill is removed, and the branch pipe is closed by a gate valve device oriented in a horizontal direction orthogonal to a branch pipe provided at an intermediate portion of the branch pipe .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, an apparatus for expanding and contracting an existing fluid pipe according to the present invention will be described with reference to FIGS.
[0016]
Numeral 1 denotes a fluid pipe such as a water pipe excavated and exposed to the ground 2, and a casing 3 composed of upper and lower half-cylindrical pipes 3a and 3a is formed on an opposing surface on an outer peripheral portion thereof. The flanges 3b are fastened by bolts 4 and nuts 5 so that a required gap S is provided between the flanges 3b and the outer peripheral surface of the fluid pipe 1.
[0017]
An annular concave groove is formed in the thick portion 3C on the inner peripheral surface of both ends of each semi-cylindrical pipe 3a, and a packing 7 is pressed into the concave groove 6 so as to press against the outer peripheral part of the fluid pipe 1. Further, a packing (not shown) integrally formed with the packing 7 is also inserted between the inner peripheral surfaces of the abutting surfaces of the upper and lower flanges 3b.
Thereby, the housing 3 is attached to the fluid pipe 1 in a watertight manner.
[0018]
The packing 7 is formed of hard rubber or the like having a small sliding resistance with respect to the outer peripheral surface of the fluid pipe 1, and reduces the resistance when rotating the housing 3 around the fluid pipe 1 as described later. The packing 7 is prevented from being damaged by kinking or the like.
[0019]
Between the inner peripheral surface of the thick portion 3C at both ends and the outer peripheral surface of the fluid pipe 1, a slight displacement is made so that the housing 3 and the fluid pipe 1 can be relatively displaced in the vertical direction perpendicular to the pipe axis. A gap is formed.
[0020]
At the center of the upper surface of the semi-cylindrical pipe 3a on the upper side, a branch pipe 8 for work as an opening is continuously connected upward, and a gate valve device 9 which is oriented in a horizontal direction orthogonal to the branch pipe 8 is provided at an intermediate part thereof. Is installed.
The gate valve device 9 rotates the operation handle 10 to move the gate valve 11 forward and backward by screw feed, thereby opening and closing the flow path in the branch pipe 8.
[0021]
A cylinder bracket 12 whose upper side has a U-shape is screwed to the horizontal flange 8a at the upper end of the branch pipe 8, and a hydraulic cylinder, for example, a hydraulic cylinder 13 is mounted on the horizontal piece 12a at the upper end of the bracket 12. It is attached with the piston rod 13a facing downward.
[0022]
A rotary actuator 15 composed of, for example, an electric motor, a pneumatic motor, or the like is mounted on a suspension base 14 attached to the lower end of the piston rod 13a, and a rotary cutting tool 16 as an end mill is mounted on the rotary chuck 15a. Is installed.
[0023]
The rotary cutting tool 16 is coaxial with the center of the branch pipe 8, and penetrates a cylindrical seal 17 provided on a base plate 12 b at a lower end of the cylinder bracket 12 so as to be slidable and rotatable up and down. It is located just above the center of the fluid pipe 1.
The rotary actuator 15 is moved up and down by the operation of the hydraulic cylinder 13 so that the tip of the rotary cutting tool 16 is cut into the outer peripheral surface of the fluid pipe 1.
[0024]
As shown in FIG. 2, a ring gear 18 having an upper and lower two-part structure is detachably bolted to the left side end surface of the housing 3 so as to be detachable between the inner peripheral surface of the ring gear 18 and the outer peripheral surface of the fluid pipe 1. Has a slight gap.
[0025]
The fluid pipes 1 on both sides of the housing 32 are supported by supports 19, 19, each having an upper end formed in a U-shape and standing on the excavated ground 2, and a right support 19 and a left support 19. The protruding pieces 19a of the support 19 are in close proximity or sliding contact with the right end of the housing 3 and the left end of the ring gear 18, respectively, to prevent the housing 3 from being displaced in the tube axis direction.
[0026]
A motor 21 is mounted on a horizontal substrate 20 bolted to the upper end of a left support 19, and a small-diameter drive gear 22 fixedly fitted to a rotating shaft 21 a facing rightward is mounted on the ring gear 18. Is engaged.
Thus, when the motor 21 is operated to rotate the drive gear 22, the ring gear 18 and the housing 3 integrated therewith are slowly rotated.
[0027]
Next, a method for expanding and contracting a fluid pipe by the above-described device will be described.
First, in the state shown in FIG. 1, the actuator 15 is operated to rotate the rotary cutting tool 16.
[0028]
Next, as shown in FIG. 4, the hydraulic cylinder 13 is operated to gradually protrude the piston rod 13 a so that the tip of the rotary cutting tool 16 slightly bites into the outer peripheral surface of the fluid pipe 1. At the same time, the motor 21 is operated to rotate the housing 3 with the packing 7 pressed against the outer peripheral surface of the fluid pipe 1.
[0029]
As shown in FIG. 3 in an enlarged manner, the housing 3 is rotated substantially once to form a cut groove 23 having a required depth on the outer peripheral surface of the fluid pipe 1, and then the rotary cutting tool 16 is slightly bitten into. The motor 21 is rotated in the reverse direction, and the housing 3 is rotated once in the reverse direction to the original position. As a result, a deeper cut groove 23 is formed on the outer peripheral surface of the fluid pipe 1.
[0030]
By rotating the housing 3 alternately in the forward and reverse directions in this manner, the fluid pipe 1 is cut at the width of the outer diameter of the rotary cutting tool 16 as shown in FIG.
If the thickness of the fluid pipe 1 is thin, it can be cut by simply rotating the housing 3 once or in one direction.
[0031]
Next, as shown in FIG. 5, after the hydraulic cylinder 13 is retracted and the rotary cutting tool 16 is pulled up to above the gate valve 11, the gate valve 11 is operated by operating the gate valve device 9 to cause the branch pipe 8 to protrude. Block the flow path.
[0032]
Next, as shown in FIG. 6, the hydraulic cylinder 13, the rotary actuator 15, and the like are all removed from the branch pipe 8 together with the cylinder bracket 12, and a closing plate 24 is attached to the flange 8 a of the branch pipe 8 to seal the branch pipe 8. The gate valve device 9 is removed, and the mounting portion is sealed.
[0033]
Finally, the ring gear 18 attached to the housing 3 is removed, and both the left and right supports 19 and the motor 21 are also removed, leaving only the housing 3 as a telescopic flexible pipe joint, and filling the exposed fluid pipe 1 back. If so, the construction ends.
[0034]
When an excessive force is applied to the fluid pipe 1 due to an earthquake, land subsidence, or the like, as shown in FIG. 7, the fluid pipe 1 can bend around the cut portion or move in the pipe axis direction. The damage is prevented.
[0035]
FIG. 8 shows an example in which two portions of the fluid pipe 1 are expanded and contracted and flexible according to the above-described procedure. In this case, the expansion and contraction and flexibility of the fluid pipe 1 are increased, and the damage prevention effect is also large. Become.
[0036]
As described above, in the present invention, the casing 3 mounted on the fluid pipe 1 in a watertight manner is rotated, and the fluid pipe 1 is cut by the rotary cutting tool 16 attached thereto. Since it is left as a joint, workability and work efficiency are greatly improved as compared with the conventional method using a sealed case.
[0037]
Further, even if the pipe diameter is large, a large-sized sealed case, a cutting machine, and the like are not required, and therefore, it is not necessary to use a heavy machine for a crane or the like for the mounting and removing work, so that the working cost is reduced. Further, since the rotary cutting tool 16 such as an end mill is used, the cutting load is small, and the hydraulic cylinder 13 and the motor 21 can be downsized.
[0038]
The present invention is not limited to the above-described embodiments, but can take various embodiments.
In the above embodiment, the ring gear 18 is mounted on the left end surface of the housing 3 and is rotated by the motor 21. However, when the diameter of the fluid pipe 1 is large and the housing 3 is large, the ring gear 18 is also provided on the right end side. The housing 3 may be rotated on both the left and right sides by providing the same ring gear 18 and motor 21 as described above. In this way, even the large casing 3 can be rotated stably.
[0039]
As shown by the imaginary line in FIG. 4, a branch pipe 8 is also provided at the center of the lower surface of the lower semicircular pipe 3a, and the same hydraulic cylinder 13, rotary actuator 15, rotary cutting tool 16 The fluid pipe 1 may be cut by two upper and lower rotary cutting tools 16. In this case, only the housing 3 needs to be rotated half a turn, so that the cutting efficiency is good, and the margin length of the hydraulic hoses and cables connected to the hydraulic cylinder 13 and the rotary actuator 15 can be reduced, and the piping, wiring, etc. Also becomes easier. When the fluid pipe 1 has a large diameter, two or more rotary cutting tools 16 and driving means for the rotary cutting tools 16 may be provided at equal intervals.
[0040]
Although a hydraulic cylinder such as a hydraulic cylinder 13 is used as a means for moving the rotary cutting tool 16 to and from the fluid pipe 1, a screw feed mechanism or the like is provided instead of such a cylinder 13 so that the rotation is manually performed. Is also good.
[0042]
Instead of the ring gear 18 and the motor 21 as the rotation driving means of the housing 3, for example, a roller chain is fixedly wound around the housing 3, and a sprocket meshed with the roller chain is driven by a motor or the like, thereby obtaining the housing 3. 3 may be rotated.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing a state before starting cutting of a fluid pipe in an apparatus of the present invention.
FIG. 2 is a front view of a line II-II in FIG. 2;
FIG. 3 is an enlarged vertical sectional front view showing a cutting procedure of a fluid pipe.
FIG. 4 is a partially cutaway side view showing a state after the fluid pipe is cut.
FIG. 5 is a partially cutaway side view showing a state in which the flow path of the branch pipe is closed by a gate valve after cutting.
FIG. 6 is a partially cutaway side view showing a state in which a cutting tool, a hydraulic cylinder, a ring gear, a motor, and the like are removed and only a housing is left.
FIG. 7 is a vertical sectional side view showing a state in which the fluid pipe is bent.
FIG. 8 is a vertical sectional side view showing an example in which a casing is attached to two places of a fluid pipe to have elasticity.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fluid pipe 2 Ground 3 Housing 3a Semi-cylindrical pipe 3b Flange 3c Thick part 4 Bolt 5 Nut 6 Annular groove 7 Packing (seal member)
8 Branch pipe 8a Horizontal flange 9 Gate valve device 10 Operating handle 11 Gate valve 12 Cylinder bracket 12a Horizontal piece 12b Base plate 13 Hydraulic cylinder (feeding means)
13a Piston rod 14 Suspension support 15 Rotary actuator 15a Rotary chuck 16 Rotary cutting tool 17 Cylindrical seal 18 Ring gear 19 Support 19a Projection 20 Horizontal board 21 Motor 21a Rotary shaft 22 Drive gear 23 Cut groove 24 Closure plate

Claims (1)

At least two cylindrical housings having at least two upper and lower divided structures having a branch pipe for work are prepared , these housings are separated from each other by a predetermined distance, and the outer peripheral surface of the existing fluid pipe is watertightly rotated around the pipe axis. After being mounted as possible, the housing is rotated by the rotation driving means , and the cylindrical seal provided on the base plate at the lower end of the feeding means coaxial with the center of the branch pipe is slidably and vertically penetrated through. By rotating an end mill and feeding the end mill toward the center of the existing fluid pipe by a feeding means , the existing fluid pipe is cut, and then the end mill is removed and a branch pipe provided at an intermediate portion of the branch pipe. Closing the branch pipe with a gate valve device which faces in a horizontal direction perpendicular to the fluid pipe.

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