JPH11336978A - Construction method for forming branch opening - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method for forming a branch opening capable of properly performing branch work so that a fusing margin of a branch saddle can be surely ensured in the case of equal diametric branching. SOLUTION: In a construction method for forming a branch opening in the case of connecting a branch pipe through a branch joint relating to an existing pipe line, a joint member 2, provided with a branch pipe take out port opposed to a side surface of an existing pipe line 1 and a work opening 2B juxtaposed in a direction at a right angle to this branch take out port 2 in a laying direction of the existing pipe line 1 to have a diameter smaller than its bore, is mounted relating to the existing pipe line 1. A drilling device 4 provided with a cutter blade 4B slidable toward the center of the existing pipe line 1 to have a bore of the work opening 2B is arranged in the work opening 2B. The cutter blade 4B of this drilling device 4 is slid toward the center of the existing pipe line, so as to cut off a peripheral wall of the existing pipe line 1 along a port edge of the work opening 2B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch opening forming method, and more particularly, to a branch opening forming method for connecting a branch pipe having substantially the same diameter to a main branch pipe using a polyethylene pipe.

[0002]

2. Description of the Related Art When taking out a branch pipe from an existing pipeline, a branch opening is formed in the pipe forming the existing pipeline, and a junction member such as a branch joint is attached to the branch opening to form a branch pipe. Are often used. By the way, in recent years, pipes are often made of a material capable of buffering an impact force at the time of an earthquake, and a flexible material such as polyethylene is used as a material therefor. Conventionally, when a branch opening is formed in an existing pipeline, for example, when a branch opening is formed on the upper peripheral surface of the existing pipeline, a split joint is attached to a branch opening formation position, and the split joint is attached to the split joint. An adapter for mounting a drilling machine is attached, and the drilling machine is set on the adapter. When the drilling machine is set, the hole saw is advanced toward the branch opening to perform the drilling.

[0003]

In the case of branching of the PE pipe described above, there is no problem in the case of branching with different diameters, but there are cases where branching with the same diameter is required for reasons such as securing a gas supply rate. is there. In this case, the branch saddle is installed so as to cover the PE pipe, but it is possible to secure a certain amount of fusion in the axial direction. However, as shown in FIG. There is a problem that the fusion allowance is reduced and the fusion of the branch saddle is incomplete.

[0004] In view of the above problems in the conventional branch opening forming method, an object of the present invention is to provide a PE pipe having the same branch diameter.
An object of the present invention is to provide a branch opening forming method capable of properly performing a branching operation by reliably securing a fusion allowance of a branch saddle.

[0005]

In order to achieve this object, an invention according to claim 1 is a method of forming a branch opening when connecting a branch pipe to an existing pipeline via a branch joint, With respect to the existing pipeline, a branch pipe outlet facing the side surface of the existing pipeline, and a diameter of the existing pipeline juxtaposed in a direction perpendicular to the branch outlet in the direction in which the existing pipeline is laid. A joint member having a work opening having a smaller diameter than the work opening is mounted, and a drilling device provided with a cutter blade slidable toward the center of the existing pipeline and having a diameter of the work opening is provided in the work opening. Then, the peripheral wall of the existing pipeline along the edge of the work opening is cut by sliding the cutter blade of the drilling device toward the center of the existing pipeline.

According to a second aspect of the present invention, in the method for forming a branch opening according to the first aspect, the small-diameter working opening has a size half the diameter of the existing pipeline and is juxtaposed. It is characterized in that by being sequentially arranged, holes are sequentially drilled along the laying direction of the existing pipeline.

According to a third aspect of the present invention, in the method for forming a branch opening according to the first aspect, the cutter blade of the drilling device has a peripheral wall corresponding to a work opening divided from another peripheral wall by shearing. It is characterized in that it is configured to be able to be accommodated in.

According to a fourth aspect of the present invention, in the method of forming a branch opening according to the first aspect, a shutter member capable of opening and closing the work opening is provided between the joint member and the punching device. It is characterized by.

[0009]

According to the first and second aspects of the present invention, a work opening having a diameter smaller than the diameter of the existing pipeline is juxtaposed to the existing pipeline, so that each of the work openings is surrounded by the existing pipeline. The difference from the diameter can be secured as a fusion allowance for the joint member. In particular, according to the second aspect of the present invention, since the working opening is half the size of the diameter of the existing pipeline, the area is twice as large as that when a working opening having the same size as the diameter of the existing pipeline is opened. Is obtained. Moreover, since this working opening is formed by punching the peripheral wall of the existing pipeline with a cutter blade slidable toward the center of the existing pipeline, work such as centering of the blade is performed as compared with the case where a rotary blade is used. Can be easily perforated without the need for

According to the third aspect of the present invention, since the peripheral wall cut by the cutter blade is housed in the cutter blade, chips and the like remain in the existing pipeline as in the case of using a hole saw. There is nothing at all. For this reason, the process after the formation of the branch opening becomes unnecessary, and the flow of the fluid in the existing pipeline can be prevented.

According to the fourth aspect of the present invention, since the shutter member capable of opening and closing the working opening is provided, gas leakage from the existing pipeline through the working opening is prevented. Can be formed without stopping the flow of the liquid.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows a configuration in which a branch opening forming method according to an embodiment of the present invention is applied to a gas pipe. In FIG. 1, reference numeral 1 denotes an existing pipeline, reference numeral 2 denotes a joint member, reference numeral 3 denotes a mounting adapter, and reference numeral 3 denotes a mounting adapter. Numeral 4 indicates a punching device. In the present embodiment, the joint member 2 is intended for a case where the diameter of the branch pipe is substantially equal to the diameter of the existing pipeline 1, and as shown in FIG. 3, the branch outlet 2A and the work opening 2B. And In the present embodiment, when it is assumed that the diameter of the branch pipe is substantially equal to the diameter of the existing pipeline 1, the existing pipeline 1
Are formed in two places, and two working openings 2B of the joint member 2 are provided in accordance with the number of bores.

The mounting adapter 3 is a member that can be integrated with the working opening 2B by fastening or the like. In the case of the present embodiment, the mounting adapter 3 has a shutter member 3A that can slide in parallel with the axis of the existing pipeline 1. ing. In the mounting adapter 3,
An opening capable of communicating with a work opening 2B of the joint member 2 is formed, and this opening is opened and closed by a shutter member 3A. The shutter member 3A is
It is provided to block outflow of gas from a branch opening formed in the existing pipeline 1.

The drilling device 4 is slidable in the cylinder 4A mounted and fixed on the mounting adapter 3 toward the center of one of the existing pipelines in the cylinder 4A, in other words, the existing pipeline 1
And a cutter blade 4B slidable in the radial direction.
As shown in FIG. 2, the cutter blade 4B is formed of a cylindrical blade having one open end in the axial direction, and a blade portion 4B1 is formed on the periphery of the tip. In the case of the present embodiment, the size of the branch opening is half the size of the diameter of the branch pipe substantially equal to the diameter of the existing pipeline 1 and two openings are formed. The outer diameter of the blade portion 4B1 of 4B is set to half the diameter of the branch pipe. Further, the blade portion 4B1 may be provided with a shear angle so that a load at the time of shearing can be applied efficiently.

The base of the cutter blade 4B is integrated with a slide rod 4C slidably supported in the cylinder 4A, and a check valve 4D is provided on the base end wall 4B2. I have. The check valve portion 4D is configured by an opening / closing lid that can cover an opening formed in the end wall 4B2.
In FIG. 2, the cutter blade 4B can be opened when the cutter blade 4B moves downward, and in FIG. 2, when the cutter blade 4B moves upward, the opening is covered and the communication between the inside of the cutter blade 4B and the outside is cut off. Has become. The check valve portion 4D is disposed at an equal position in the circumferential direction of the end wall 4B2,
Is made to have an equal pressure inside. The reason why the inside of the cutter blade 4B is made to have a uniform pressure will be described later.
This is because when the cut peripheral wall enters the inside, the space on the side of the end wall 4B2 is made to have a negative pressure so that the cut peripheral wall can be easily sucked.

In the present embodiment, when the branch opening is formed by using the above configuration, the procedure shown in FIGS. 3 to 7 is executed. (1) Attachment of the joint member 2 In this work, as shown in FIG. 3, the joint member 2 having the work openings 2B formed at two places is positioned at the branch take-out portion of the existing pipeline 1, and the saddle portion is heated by high frequency. And are integrated by fusing.

(2) Connecting the branch pipe to the joint member 2 In this operation, as shown in FIG. 4, the branch pipe 6 is connected to the branch outlet 2A of the joint member 2 via the relay member 5.

(3) Installation of the mounting adapter 3 and the drilling device 4 on the joint member 2 and formation of the work opening 2B In this work, one of the work openings 2B of the joint member 2 was closed as shown in FIG. Joint member 2 while maintaining the state
The mounting adapter 3 is fastened to the work opening 2B, and the punching device 4 is placed and fixed on the mounting adapter 3. Drilling device 4
Although not shown, the end of a chain or the like looped around the existing pipeline 1 is latched and pressed against the mounting adapter 3. At this time, the shutter member 3A of the mounting adapter 3 is open. After the installation of the mounting adapter 3 and the drilling device 4, the work opening 2B
Is formed. In this operation, as shown in FIG. 5, when the sliding rod 4C of the drilling device 4 is pushed down, the cutter blade 4B causes the peripheral wall of the existing pipeline 1 at the branch opening forming position to have a diameter of half the diameter of the branch opening. To cut. When the cutter blade 4B is pushed down, the check valve portion 4D of the cutter blade 4B is opened, and the inside of the cutter blade 4B communicates with the atmosphere. At the time of cutting, the peripheral wall corresponding to the branch opening divided from the other peripheral wall enters the inside of the cutter blade 4B as shown by a two-dot chain line in FIG. Then, cutter blade 4B
Is retracted into the cylinder 4A, the inside of the cutter blade 4B is closed by the inertia due to the movement of the cutter blade 4B in the process of being pulled back, so that the inside of the cutter blade 4B tends to have a negative pressure. The fall of the cut peripheral wall is prevented. Working aperture 2 drilled in this way
As shown in FIG. 6, B has a small perforation area with respect to the saddle portion (the portion indicated by the two-dot chain line) of the joint member 2, so that the difference in the size is the fusion allowance of the saddle portion. Regarding this fusion allowance, the fusion allowance at the portion indicated by the arrow in FIG. 9 is significantly increased.

(4) Removal of the Mounting Adapter 3 and the Punching Device 4 In this operation, the punching device 4 in which the cutter blade 4B is moved into the cylinder 4A is removed from the mounting adapter 3, and FIG.
As shown in (2), the shutter member 3A of the mounting adapter 3 is closed to shut off gas leakage from the branch opening 1A '. Thereafter, a cap 7 (see FIG. 7) is attached to the work opening 2B of the joint member 2 to which the mounting adapter 3 has been attached, and one of the work openings 2B is sealed.

When the above operation is completed, as shown in FIG. 8, the operations (3) and (4) are repeated for the other operation opening 2B in the joint member 2. FIG. 7 shows a mounting state of the mounting adapter 3 for another working opening 2B.

According to the present embodiment, when forming a branch opening in the existing pipeline 1, it is only necessary to shear the peripheral wall corresponding to the branch opening. Generates less heat in the existing pipeline. This makes it possible to prevent wear of the cutter blade 4B and improve the durability of the cutter blade 4B. Also, as shown in FIG. 2, since the inner peripheral surface of the cutter blade 4B has an inclined surface at the cutting edge, the edge of the working opening 2B is cut into a shape perpendicular to the laying direction of the existing pipeline 1. The edge of the working opening 2B does not become an inclined surface due to shaving. This prevents the gas flowing out of the existing pipeline 1 from being throttled at the edge of the work opening 2B, thereby preventing the flow rate from decreasing.

[0022]

As is apparent from the above embodiments, according to the first and second aspects of the present invention, a work opening having a diameter smaller than the diameter of the existing pipeline is provided in parallel with the existing pipeline. In this way, a difference from the diameter of the existing pipeline can be secured around each working opening as a margin for fusion of the joint member. In particular, according to the second aspect of the present invention, since the working opening is half the size of the diameter of the existing pipeline, it is twice as large as when the working opening having the same size as the diameter of the existing pipeline is opened. Is obtained. Moreover, since this working opening is formed by punching the peripheral wall of the existing pipeline with a cutter blade slidable toward the center of the existing pipeline, work such as centering of the blade is performed as compared with the case where a rotary blade is used. Can be easily perforated without the need for Thereby, the fusion of the branch saddle can be reliably performed, so that an appropriate branch opening can be formed.

According to the third aspect of the present invention, since the peripheral wall cut by the cutter blade is housed in the cutter blade, chips and the like are present in the existing pipeline as in the case of using a hole saw. There is no residue. For this reason, the process after the formation of the branch opening becomes unnecessary, and the flow of the fluid in the existing pipeline can be prevented.

According to the fourth aspect of the present invention, since the shutter member capable of opening and closing the working opening is provided, gas leakage from the existing pipeline through the working opening is prevented. The branch opening can be formed without stopping the flow of the gas, and the interruption of the supply of the fluid such as gas during the branch opening forming operation can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining an apparatus used in a branch opening forming method according to an embodiment of the present invention.

FIG. 2 is a perspective view for explaining a configuration of a cutter blade in the apparatus shown in FIG.

FIG. 3 is a schematic diagram for explaining an installation work of a joint member in a branch opening forming method according to an embodiment of the present invention.

FIG. 4 is a schematic view for explaining a connection operation state of branch pipes in a branch opening forming method according to an embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining a working opening forming state using a punching device in the branch opening forming method according to the embodiment of the present invention.

6 is a schematic diagram for explaining a fusion state between the work opening and the joint member shown in FIG. 5;

FIG. 7 is a schematic diagram for explaining a state in which the punching device is removed after the branch opening shown in FIG. 5 is formed.

FIG. 8 is a schematic diagram for explaining an installation state of a mounting adapter for mounting a drilling device for another working opening in a joint member.

FIG. 9 is a schematic diagram for explaining a fused state of a joint member in a conventional branch opening forming method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Existing pipe line 2 Joint member 2A Branch take-out opening 2B Work opening 3 Mounting adapter 4 Drilling device 4A Cylinder 4B Cutter blade 4B1 Blade part 4B2 End wall 4D Check valve part

Claims (4)

[Claims] 1. A method of forming a branch opening when connecting a branch pipe to an existing pipeline via a branch joint, wherein the branch pipe is taken out of the existing pipeline by opposing a side surface of the existing pipeline. A joint member having a mouth and a working opening having a diameter smaller than the diameter of the existing pipeline, which is juxtaposed in the direction perpendicular to the branch outlet in the direction in which the existing pipeline is laid, is attached to the work opening. A piercing device provided with a cutter blade slidable toward the center of the existing pipeline and having a diameter of the working opening, wherein the cutter blade of the piercing device is slid toward the center of the existing pipeline. A method for forming a branch opening, wherein the peripheral wall of the existing pipeline is cut along the edge of the working opening. 2. The branch opening forming method according to claim 1, wherein the small-diameter working openings are half the diameter of the existing pipeline and arranged side by side, and the drilling devices are sequentially arranged. A branch opening forming method, wherein holes are sequentially drilled along a direction in which the existing pipeline is laid. 3. The branch opening forming method according to claim 1, wherein the cutter blade of the drilling device can house a peripheral wall of a portion corresponding to a work opening divided from another peripheral wall by shearing. A branch opening forming method characterized by having a configuration. 4. The branch opening forming method according to claim 1, wherein a shutter member capable of opening and closing the work opening is provided between the joint member and the drilling device. Forming method.