JP2020185616A - Fluid pipe full-cut cutting method and full-cut cutting device - Google Patents

Abstract

To provide fluid pipe full-cut cutting method and full-cut cutting device which reduce a cutting space, and can realize down-sizing of a housing.SOLUTION: Full-cut cutting of a city water pipe 1 is performed in a non-interrupted flow state in a housing, which surrounds the city water pipe 1 in a sealed manner, through a drilling process and a dividing process. In the drilling process, a drilled hole 10 is formed in a peripheral wall of the city water pipe 1 by use of a cylindrical cutter which has a diameter smaller than a diameter D1 of the city water pipe 1. In the dividing process, the city water pipe 1 is cut off in a pipe axis direction while causing a rotation mechanism 43 of a pair of disk-like cutters 41, 41 to penetrate into the drilled hole 10 by use of the pair of disk-like cutters 41, 41 which rotate around an axis A41 extending in the pipe axis direction.SELECTED DRAWING: Figure 8

Description

The present invention relates to a method and an apparatus for performing so-called full-cut cutting in which a fluid pipe is separated in the pipe axial direction.

Conventionally, an existing water pipe (an example of a fluid pipe) is surrounded by a housing in a sealed manner, and after the water pipe is fully cut in a state of continuous water inside the housing, a valve device or the like is used in the cutting space of the water pipe. The work of inserting an insert is known. In such construction, as described in Patent Documents 1 to 3, it is common to perform full-cut cutting using a cutting machine having a cylindrical cutter such as a hole saw.

FIG. 13 schematically shows a water pipe after full-cut cutting with a hole saw. The diameter D9 of the hole saw (not shown) is larger than the pipe diameter D91, and the water pipe 91 is separated in the pipe axial direction (left-right direction in FIG. 13). The required width NW is the width required to insert an insert such as a sluice valve. When a hole saw having a diameter smaller than the diameter D9 is used, the required width NW is not secured. That is, in order to secure the required width NW, it is essential to use a hole saw having a diameter of D9 or more, and a cutting space 90 is provided in a circular shape in a plan view with a size corresponding to the diameter.

In full-cut cutting with a hole saw, the cutting space 90 becomes larger than necessary. This is because the cutting space 90 includes a portion that overhangs in the pipe axis direction with respect to the required width NW, such as the region shown by hatching. The housing 92 must have a size and shape that includes such a cutting space 90, and is therefore difficult to miniaturize. In FIG. 13, the housing 92 is schematically represented by the outline of the inner surface of the housing.

Japanese Unexamined Patent Publication No. 2016-61391 Japanese Unexamined Patent Publication No. 2016-70464 Japanese Unexamined Patent Publication No. 2016-223528

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a full-cut cutting method and a full-cut cutting device for a fluid pipe, which can reduce the cutting space and realize a miniaturization of a housing. is there.

The full-cut cutting method for a fluid pipe according to the present invention is a full-cut cutting method for a fluid pipe in which the fluid pipe is fully cut in a non-disruptive state inside a housing that surrounds the fluid pipe in a sealed manner. Using a cylindrical cutter having a diameter smaller than the diameter of the pipe, a drilling step of forming a drill in the peripheral wall of the fluid pipe and a pair of disk-shaped cutters rotating around an axis extending in the pipe axis direction are used. The present invention includes a dividing step of separating the fluid pipe in the pipe axis direction while allowing the rotation mechanism of the pair of disk-shaped cutters to penetrate the perforation.

According to such a method, since the fluid pipe is separated by a length corresponding to the distance between the pair of disk-shaped cutters, the cutting space can be provided small so as not to project larger in the pipe axis direction than the required width. Further, by invading the perforation with the rotation mechanism of the disk-shaped cutter, a disk-shaped cutter having a relatively small diameter can be used. As a result, the size of the housing can be reduced.

In the dividing step, it is preferable to allow the tips of the pair of disk-shaped cutters to penetrate the perforations. As a result, the pair of disk-shaped cutters can be rotated in a stable state.

When the pair of disk-shaped cutters are moved away from the fluid tube, it is preferable to hook and collect the sections generated in the dividing step. As a result, the sections produced in the dividing step can be easily collected.

The full-cut cutting device for a fluid pipe according to the present invention has a first housing having a housing that seals the fluid pipe and a cylindrical cutter for forming a perforation in the peripheral wall of the fluid pipe inside the housing. A cutting machine and a second cutting machine having a pair of disk-shaped cutters for cutting the fluid pipe in the pipe axis direction inside the housing are provided, and the second cutting machine is provided in the pipe axis direction. It has a rotation mechanism capable of rotating the pair of disk-shaped cutters around the extended axis and penetrating the drilling.

According to such a device, since the fluid pipe is separated by a length corresponding to the distance between the pair of disk-shaped cutters, the cutting space can be provided small so as not to project larger in the pipe axial direction than the required width. Further, by invading the perforation with the rotation mechanism of the disk-shaped cutter, a disk-shaped cutter having a relatively small diameter can be used. As a result, the size of the housing can be reduced.

It is preferable that the distance between the pair of disk-shaped cutters is smaller than the diameter of the cylindrical cutter. As a result, the tips of the pair of disc-shaped cutters can be penetrated into the drilling, and the pair of disc-shaped cutters can be rotated in a stable state.

It is preferable that the second cutting machine has a section collecting portion configured to pass through the perforation and be locked on the inner surface of the section. As a result, the sections can be easily collected.

It is preferable that the pair of disk-shaped cutters are formed with through holes penetrating in the thickness direction. As a result, a continuous flow state can be ensured even in a situation where the inside of the fluid pipe is blocked by the disk-shaped cutter.

Cross-sectional view of the water pipe before the drilling process as seen from the pipe axis direction Cross-sectional view of the water pipe in the drilling process as seen from the pipe axis direction (A) plan view and (B) side view sectional view showing a water pipe in which a perforation is formed. Cross-sectional view of the water pipe before the cutting process as seen from the pipe axis direction (A) front view and (B) side view showing a pair of disk-shaped cutters Cross-sectional view of the water pipe in the dividing process as seen from the pipe axis direction (A) plan view and (B) side view sectional view showing a water pipe after full-cut cutting (A) front view and (B) side view sectional view showing a water pipe in which a pair of disk-shaped cutters are brought close to each other. (A) front view and (B) side view sectional view showing a water pipe in a dividing process (A) front view and (B) side sectional view showing a state of collecting the sections generated in the cutting step. Cross-sectional view of the water pipe before the insertion process as seen from the pipe axis direction Top view schematically showing a water pipe fully cut according to the present embodiment Top view schematically showing a water pipe that has been fully cut by the conventional method

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an existing water pipe 1 (an example of a fluid pipe) forming a part of a pipeline. The water pipe 1 is a ductile cast iron pipe, but is not limited to this, and may be, for example, a steel pipe. In the present embodiment, inside the housing 2 that surrounds the water pipe 1 in a sealed manner, the water pipe 1 is fully cut in a continuous water state (continuous flow state), and a valve device (valve device) is used in the cutting space of the water pipe 1. An example of inserting (an example of an insert) is shown. Such construction is carried out, for example, to branch an existing pipeline before and after a section for renewing a water pipe to provide a bypass pipeline.

The housing 2 encloses a part of the water pipe 1 in a water flow state in a sealed manner. The housing 2 has a split structure that can be fitted externally to the existing water pipe 1, and more specifically, it has an upper and lower split structure in which the upper member 21 and the lower member 22 are joined to each other. This joining is performed by a fastener (not shown) composed of bolts and nuts, but instead of this, joining may be performed by welding or the like. The bottom 2B of the housing 2 is formed in a mortar shape. A discharge hole 23 for discharging chips generated during cutting is provided at the central portion of the bottom portion 2B.

The housing 2 is composed of a split T-shaped pipe, and a branch portion 24 extending in a direction intersecting the pipe axis direction (direction perpendicular to the paper surface of FIG. 1) of the water pipe 1 is directed upward. A work valve (work sluice valve) 26 and a sealing case 27 are connected to the branch portion 24 via a tubular adapter 25. The work valve 26 shown in FIG. 1 is in a closed state, and the internal space of the housing 2 and the internal space of the closed case 27 are separated by a valve body 26v. The cutting machine 3 (corresponding to the first cutting machine) is arranged above the housing 2 and is connected to the sealed case 27. The cutting machine 3 has a hole saw 31 which is a cylindrical cutter for forming a hole in the peripheral wall of the water pipe 1 inside the housing 2.

The hole saw 31 has a diameter D31 smaller than the pipe diameter D1 of the water pipe 1. The hole saw 31 is fixed to the tip of the shaft 33 together with the center drill 32 provided at the center of the shaft. In FIG. 1, the shaft 33 is pulled up so that the hole saw 31 is arranged inside the sealed case 27. The cutting machine 3 has a rotation mechanism (not shown) that rotates the shaft 33 about an axis A33 extending in the vertical direction. Along with the rotation of the shaft 33, the hole saw 31 and the center drill 32 rotate around the axis A33.

In the full-cut cutting method of the water pipe 1 in the present embodiment, a drilling step of forming a hole in the peripheral wall of the water pipe 1 using a hole saw 31 and a pair of disc-shaped cutters 41, 41 described later are used to cut the water pipe 1. It is provided with a dividing step of separating in the pipe axis direction. Further, the present embodiment shows an example including a recovery step of collecting a section generated by full-cut cutting of the water pipe 1 and an insertion step of inserting a valve device as an inserter into the cutting space of the water pipe 1. Hereinafter, each step will be specifically described.

As shown in FIG. 2, in the drilling step, after the valve body 26v is displaced to open the working valve 26, the shaft 33 is pushed down to lower the hole saw 31, and the hole saw is inserted into the housing 2 through the branch portion 24. Invade 31. Then, by bringing the rotating hole saw 31 into contact with the peripheral wall of the water pipe 1, a perforation 10 as shown in FIG. 3 is formed on the peripheral wall of the water pipe 1. The diameter D10 of the perforation 10 corresponds to the diameter D31 of the hole saw 31, and is smaller than the pipe diameter D1 of the water pipe 1. After the perforation 10 is formed, the hole saw 31 is raised, and the curved plate-shaped section P1 housed inside the hole saw 31 is hooked by the center drill 32 and collected.

After raising the hole saw 31, the working valve 26 is closed, the cutting machine 3 is removed, and the cutting machine 4 (corresponding to the second cutting machine) as shown in FIG. 4 is connected instead. That is, after the drilling step and before the dividing step, the cutting machine 3 is replaced with the cutting machine 4. In the present embodiment, the sealed case 27 is replaced with the sealed case 28, but the present invention is not limited to this, and the conventional sealed case 27 may also be used. As shown in FIGS. 4 and 5, the cutting machine 4 has a pair of disc-shaped cutters 41 and 41 for separating the water pipe 1 in the pipe axial direction inside the housing 2. The pair of disc-shaped cutters 41 and 41 are attached to the tip portions of the shaft 42, respectively, and are configured to be rotatable around an axis A41 extending in the pipe axis direction. The shaft 42 has an outer cylinder 42a extending in the vertical direction and a rotating shaft 42b inserted into the outer cylinder 42a.

The cutting machine 4 has a rotation mechanism 43 that rotates a pair of disk-shaped cutters 41, 41 about an axis A41, and a drive source (not shown) such as an engine or an electric motor. The rotation mechanism 43 is located at the center of rotation of the disk-shaped cutter 41. The rotating mechanism 43 includes a rotating shaft 44 extending in the pipe axis direction, a tubular case 45 covering the rotating shaft 44, and a gear mechanism for interlocking and connecting the rotating shaft 44 to the rotating shaft 42b. Inside the case 45, the bevel gear 46 located at the tip of the rotating shaft 42b meshes with the bevel gear 47 located in the middle of the rotating shaft 44. The rotational power generated from the drive source is transmitted to the rotary shaft 42b, and the rotary shaft 44 rotates in conjunction with the rotation of the rotary shaft 42b.

A disk-shaped cutter 41 is detachably attached and fixed to both ends of the rotating shaft 44 via nuts 48, respectively. In the present embodiment, the diameter D41 of the disk-shaped cutter 41 is larger than the pipe diameter D1, and the radius R41 is smaller than the pipe diameter D1. As the disk-shaped cutter 41, for example, a diamond cutter, a metal saw (circular saw), a cutting grindstone, or the like can be used. The length L43 of the rotating mechanism 43 in the horizontal direction is smaller than the diameter D31 of the hole saw 31 and therefore smaller than the diameter D10 of the drilling 10. Therefore, as will be described later, the rotation mechanism 43 can be inserted into the perforation 10.

As shown in FIG. 6, in the dividing step, the valve body 26v is displaced to open the working valve 26, the shaft 42 is pushed down to lower the pair of disc-shaped cutters 41 and 41, and the housing 2 is passed through the branch portion 24. A pair of disc-shaped cutters 41 and 41 are inserted into the inside of the. Then, by bringing the pair of rotating disk-shaped cutters 41, 41 into contact with the peripheral wall of the water pipe 1, the water pipe 1 is separated in the pipe axial direction as shown in FIG. The water pipe 1 is provided with a cutting space 40 having a length L40 corresponding to the distance G (see FIG. 5) between the pair of disk-shaped cutters 41 and 41. The cutting space 40 is provided in a substantially rectangular shape in a plan view, and does not include a portion that projects larger in the pipe axis direction than the cutting width NW (see FIG. 12).

FIG. 8 shows a state immediately after the pair of disc-shaped cutters 41 and 41 come into contact with the water pipe 1, and the water pipe 1 is gradually cut by pushing down the shaft 42 thereafter. If necessary, by operating the valve 23v to temporarily open the discharge hole 23, chips generated by cutting can be discharged to the outside. As shown in FIG. 9, in the process of cutting the water pipe 1, the rotating mechanism 43 invades the perforation 10. That is, in the dividing step, the water pipe 1 is separated in the pipe axial direction while the rotating mechanism 43 is penetrated into the drilling 10. As a result, the water pipe 1 can be fully cut by using a disk-shaped cutter 41 having a relatively small diameter and a radius R41 smaller than the pipe diameter D1.

On the other hand, when the water pipe 1 is separated without letting the rotating mechanism penetrate the perforation 10, the rotating mechanism comes into contact with the outer surface of the water pipe 1 and the shaft 42 does not push down, so that the radius is larger than the pipe diameter D1. It will be necessary to use a disc-shaped cutter with a relatively large diameter. As a result, it is inevitable that the size of the sealed case 28 for accommodating the disk-shaped cutter, the work valve 26, the housing 2, and the like will be increased. Intruding the rotating mechanism 43 into the drilling 10 in this way contributes to reducing the diameter of the disk-shaped cutter, and is convenient for realizing the miniaturization of the housing 2, the working valve 26, the sealed case 28, and the like. In the present embodiment, the length L43 of the rotating mechanism 43 is smaller than, but not limited to, the distance G between the pair of disc-shaped cutters 41 and 41.

In the present embodiment, the pair of disc-shaped cutters 41, 41 are arranged so as to sandwich the center position of the drilling 10, and the distance G between them is smaller than the diameter D31 of the hole saw 31 and therefore smaller than the diameter D10 of the drilling 10. .. Therefore, in the dividing step, as shown in FIG. 8, the tip portions (lower end portions in the present embodiment) of the pair of disk-shaped cutters 41 and 41 can be penetrated into the drilling 10. Such a method is preferable for rotating the pair of disk-shaped cutters 41, 41 in a stable state. However, the present invention is not limited to this, and a pair of disk-shaped cutters having a larger interval than the diameter D10 of the drilling 10 may be used.

The pair of disc-shaped cutters 41, 41 are arranged so that their thickness directions are directed toward the pipe axis. Further, the pair of disk-shaped cutters 41 and 41 are formed with through holes 41h penetrating in the thickness direction, respectively. Through holes 41h are formed at a plurality of locations (eight locations in the present embodiment) around the axis 41. As a result, water flows through the through hole 41h, so that a continuous water state is ensured even when the disk-shaped cutter 41 closes the inside of the water pipe 1 as shown in FIGS. 6 and 9. The through hole 41h is formed in a circular shape when viewed from the pipe axis direction, but is not limited to this.

After separating the water pipe 1 in the pipe axis direction, the pair of disk-shaped cutters 41 and 41 are raised to move them away from the water pipe 1. At that time, as shown in FIG. 10, the short tubular section P2 generated in the dividing step is hooked and collected. The cutting machine 4 has a section collecting unit 49 configured so as to pass through the perforation 10 and be locked on the inner surface of the section P2. In the present embodiment, a pair of section collecting portions 49 are provided, each of which protrudes from the shaft 42 and is rotatably supported by the shaft 42. In FIG. 10 (A), the disc-shaped cutter 41 in the foreground is omitted so as to show the intercept collecting portion 49, and FIGS. 8 (A) and 9 (A) are the same.

The pair of section collecting portions 49, 49 are opened in a V shape when viewed from the pipe axis direction, and the open posture is maintained by the action of an urging member (not shown) such as a spring. The width W49 of the section collection section in the open position (see FIG. 8) is larger than the diameter D31 of the hole saw 31 and therefore larger than the diameter D10 of the perforation 10. As shown in FIG. 9, the intercept collecting portion 49 in contact with the outer surface of the water pipe 1 rotates in the closing direction by a force pushing down the shaft 42, becomes smaller than the diameter D10, and can pass through the perforation 10. The section collecting section 49 that has passed through the perforation 10 opens inside the water pipe 1 by the action of the urging member and locks on the inner surface of the section P2.

After raising the pair of disc-shaped cutters 41 and 41 with the intercept P2 hooked, the working valve 26 is closed, the cutting machine 4 is removed, and the insertion machine 5 as shown in FIG. 11 is connected instead. In the present embodiment, the sealed case 28 is replaced with the sealed case 29, but the present invention is not limited to this, and the conventional sealed case 28 may also be used. By pushing down the operating rod 51 of the insertion machine 5 to lower the valve device 50 and arranging the valve device 50 inside the housing 2 through the branch portion 24, the valve device 50 is inserted into the cutting space 40 as shown in FIG. The valve device 50 is configured as a sluice valve with a built-in valve body (not shown). In FIGS. 11 and 12, the valve device 50 is shown in outline, and detailed description of its appearance is omitted.

The length L40 of the cutting space 40 can be appropriately adjusted by changing the distance G between the pair of disc-shaped cutters 41 and 41. The interval G can be changed by replacing it with a disk-shaped cutter having a different width W41 (see FIG. 5) in the tube axis direction. Therefore, the length L40 is set to a dimension close to the width dimension (that is, the required width NW) required for inserting the valve device 50, and the cutting space 40 is provided small. Further, as described above, in the present embodiment, a disk-shaped cutter 41 having a relatively small diameter can be used. As a result, the size of the housing 2 can be reduced. In FIG. 12, the housing 2 is schematically represented by the outline of the inner surface of the housing.

Although not adopted in this embodiment, in order to suppress the vibration of the shaft 42 in the dividing step, the shaft 42 may be supported from the side by the support members 6 and 6 as shown by the broken lines in FIG. .. The support member 6 is configured to be displaceable between a position close to the shaft 42 (see FIG. 6) and a position away from the shaft 42 in response to an operation from the outside. The support members 6 and 6 are provided, for example, in the closed case 28, but are not limited to this, and may be provided in the upper member 21, the adapter 25, the work valve 26, or another member of the housing 2.

In the present embodiment, an example in which the valve device 50 is configured as a sluice valve is shown, but the present invention is not limited to this, and for example, the valve device 50 may be configured as a switching valve capable of switching the flow path. Further, the insert is not limited to the valve device, and may be, for example, a shielding member that shields the flow path.

The present invention can be applied to water pipes, but is not limited to this, and can be widely applied to fluid pipes used for various liquids other than water and fluids such as gases.

The present invention is not limited to the above-described embodiment, and various improvements and changes can be made without departing from the spirit of the present invention.

1 Water pipe (an example of fluid pipe)
2 Housing 3 Cutting machine (first cutting machine)
4 Cutting machine (second cutting machine)
5 Inserting machine 10 Drilling 26 Work valve 27 Sealed case 31 Hole saw 40 Cutting space 41 Disc-shaped cutter 41h Through hole 43 Rotating mechanism 49 Section recovery unit 50 Valve device (example of inserter)
P1 intercept P2 intercept

Claims (7)

In a full-cut cutting method for a fluid pipe, in which the fluid pipe is fully cut in a continuous flow state inside a housing that surrounds the fluid pipe in a sealed manner.
A drilling step of forming a punch in the peripheral wall of the fluid pipe using a cylindrical cutter having a diameter smaller than the diameter of the fluid pipe.
Using a pair of disc-shaped cutters that rotate around an axis extending in the pipe axis direction, a dividing step of separating the fluid pipe in the pipe axis direction while allowing the rotation mechanism of the pair of disc-shaped cutters to penetrate the perforation. A full-cut cutting method for a fluid pipe, which comprises. The full-cut cutting method for a fluid pipe according to claim 1, wherein in the dividing step, the tip portions of the pair of disk-shaped cutters are made to penetrate into the perforation. The full-cut cutting method for a fluid tube according to claim 1 or 2, wherein when the pair of disk-shaped cutters are moved away from the fluid tube, the sections generated in the dividing step are hooked and collected. A housing that seals the fluid tube and
A first cutting machine having a cylindrical cutter for forming a perforation in the peripheral wall of the fluid pipe inside the housing.
A second cutting machine having a pair of disk-shaped cutters for separating the fluid pipe in the pipe axial direction inside the housing is provided.
A full-cut cutting device for a fluid pipe, wherein the second cutting machine has a rotation mechanism capable of rotating the pair of disk-shaped cutters around an axis extending in the pipe axis direction and penetrating the perforation. The full-cut cutting device for a fluid pipe according to claim 4, wherein the distance between the pair of disk-shaped cutters is smaller than the diameter of the cylindrical cutter. The full-cut cutting device for a fluid tube according to claim 4 or 5, wherein the second cutting machine has a section collecting portion configured to pass through the perforation and be locked on the inner surface of the section. The full-cut cutting device for a fluid pipe according to any one of claims 4 to 6, wherein through holes penetrating in the thickness direction are formed in the pair of disk-shaped cutters.

Images