JP2002011792A - Branching and connecting method for thermoplastic resin pipe, and branch pipe employed for the connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and sure branching and connecting method for a thermoplastic resin pipe, which is reduced in the man-hour of a connecting work and excellent in air-tightness, and a branch pipe employed fro the connecting method. SOLUTION: In the connecting method of a thermoplastic resin branch pipe to a thermoplastic resin main pipe while branching the branch pipe, a flange is integrated previously with the one end of the branch pipe and the branch pipe is turned under a condition that the flange is abutted against the outer peripheral surface of the main pipe by pressure whereby the branch pipe is welded to the main pipe through fusion welding by friction heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining and joining thermoplastic resin tubes by welding.

[0002]

2. Description of the Related Art In a piping system through which a fluid such as a gas or a liquid passes, it is necessary to provide a branch connection for branching or merging the fluid.

In order to join the branch pipe to the main pipe, a branch joint such as a cheese or a saddle is generally used. In this case, the main pipe and the branch joint, and the branch joint and the branch pipe are butt-fused and electro-fused with each other. , And bonded by an adhesive.

[0004]

In the above-mentioned joining method, the joining man-hour required for joining the pipe and the branch joint is increased, and there is a problem that the joining cost is increased. In particular, in the case of electrofusion, a configuration in which a linear heating wire is wound and buried in the joint surface of the branch joint is manufactured by an injection molding method, and the linear heating wire is buried. However, there is a problem that the production cost of the branch joint is increased because it is complicated and the productivity is reduced. In addition, the linear heating wire may move and not be fixed at a predetermined position due to the injection pressure at the time of injection molding, and the joint surface may not be uniformly heated, or the heating wire may be short-circuited when energized.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to solve these problems without using a branch joint in which a heating wire is embedded. An object of the present invention is to provide a branch joining method for a thermoplastic resin pipe that has simple and reliable airtightness with a small number of joining steps, and a branch pipe used for the joining method.

[0006]

According to the present invention, there is provided a method of branching and joining a thermoplastic resin branch pipe to a thermoplastic resin main pipe, wherein a flange portion is integrally formed in advance at one end of the branch pipe, The main pipe and the branch pipe are welded by frictional heat by pressing the flange portion against the outer peripheral surface of the thermoplastic resin main pipe and rotating the branch pipe.
After the branch pipe is rotated while being pressed against the main pipe, the branch pipe may be pressed against the main pipe with a stronger pressure to ensure the welding.

Further, according to the branch joining method of a thermoplastic resin pipe of the present invention, a lid for closing a flow path is provided in the vicinity of an opening on a flange portion side of the thermoplastic resin branch pipe, and by rotating the branch pipe, friction is generated. After welding the main pipe and the branch pipe by heat, it is desirable to form a communication hole in the outer peripheral surface of the lid and the main pipe by propelling a cutter from inside the other end opening of the branch pipe. .

A thermoplastic resin branch pipe according to the present invention is a thermoplastic resin branch pipe which branches and is joined to a thermoplastic resin main pipe, wherein a flange is integrally formed at one end in advance, and Is rotationally welded while being pressed against the outer peripheral surface of the thermoplastic resin main pipe.

Further, in the thermoplastic resin branch pipe of the present invention, it is desirable to provide a lid for closing the flow passage near the opening on the flange side.

[0010]

According to the method of branch joining of a thermoplastic resin pipe of the present invention, a flange is integrally formed at one end of the thermoplastic resin branch pipe in contact with the joint, and the flange is formed of a thermoplastic resin. By pressing the pipe so as to wrap the outer peripheral surface thereof and rotating the branch pipe in that state, frictional heat is generated at the joint portion, and the joint portion is uniformly heated and melted to the extent that it can be fused. When the rotation of the branch pipe is stopped, the molten portion is cooled and solidified to be integrated, and the branch pipe is fixed to the main pipe in a sealed state. As described above, since the heating wire is not required for the flange portion of the thermoplastic resin branch pipe, there is no need for complicated work such as embedding the heating wire inside the main pipe joining surface of the flange portion, and an inexpensive one is used. Can be used.

In addition, since a lid for closing the flow path is provided in the vicinity of the opening on the flange portion side of the thermoplastic resin branch pipe, scattering of frictional debris generated from the melted portion due to rotation is suppressed, and the outer peripheral surface of the resin main pipe is removed. Friction debris is sealed in the space formed by the lid, and does not adhere to the inner peripheral surface of the branch pipe.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a branch joining method of a thermoplastic resin pipe of the present invention and a branch pipe used for the joining method, and FIG. 2 is a longitudinal sectional view showing a drilling operation state before drilling a cutter. FIG. 3 is a longitudinal sectional view showing a drilling operation state during cutter drilling, and FIG. 4 is a longitudinal sectional view showing a drilling operation state after cutter drilling.

In FIG. 1, a flange 3 is integrally formed at an end of a thermoplastic resin branch pipe 2 to be joined to an outer peripheral surface of a thermoplastic resin main pipe 1. Preferably, the contact surface 3a of the flange portion 3 with the thermoplastic resin main pipe 1 is a flat surface. Further, since the outer peripheral surface of the main pipe 1 and the contact surface 3a of the flange portion 3 are in contact with each other with a line, the outer peripheral surface 1a to be brought into contact with the main pipe 1 is formed into a flat surface in advance so that the two are brought into contact. Is desirable. Further, as shown in FIGS. 2 to 4, a lid 3b for closing the flow path Y may be provided in the vicinity of the opening of the thermoplastic resin branch pipe 2 on the flange side.

The thermoplastic resins which can be used in the present invention include polyolefins such as polyethylene and polypropylene, polyamides such as nylon, polystyrene, polyvinyl chloride, polybutylene terephthalate, modified polyphenylene oxide, polycarbonate, polyacetal and the like. .

The rotary welding device 4 comprises a support arm 5, a cylinder 6, a guide rail 7, a support bar 8, a motor 9, a joint clamp 10 and the like. A cylinder 6 driven by fluid pressure is fixed to the support arm 5, and a support bar 8 is attached to the tip of the cylinder 6 via a guide rail 7 so as to be movable in the vertical direction. Further, a motor 9 is fixed to the support bar 8, and a joint clamp 10
Is attached.

Next, a description will be given of a method of branching and joining thermoplastic resin pipes using the above apparatus. The joining method will be described as an example in which a main pipe made of polyethylene having a diameter of 150 mm is used as the thermoplastic resin main pipe 1 and a branch pipe made of polyethylene having a diameter of 30 mm is used as the thermoplastic resin branch pipe 2.

The polyethylene branch pipe 2 is rotated by a rotary welding device 4
Attach to That is, the joint clamp 10 is opened, the polyethylene branch pipe 2 is inserted, and the joint clamp 10 is closed in the state of FIG. 1 to grip the outer peripheral surface of the polyethylene branch pipe 2. At this time, a plurality of ridges may be provided on the outer periphery of the polyethylene branch pipe 2 in the axial direction in order to provide a non-slip effect (not shown).

Next, the position of the entire rotary fusion device 4 is set so that the axis of the polyethylene branch pipe 2 is perpendicular to the axis of the polyethylene main pipe 1. Then, the cylinder 6 is driven by the fluid pressure to press the polyethylene branch pipe 2 downward with a pressing force of 4.1 to 7.1 kgf (40 to 70 N), and the flange portion 3 of the polyethylene branch pipe 2 and the polyethylene binding pipe are pressed. The outer peripheral surface 1a of the tube 1 is brought into close contact. Further, in this state, the motor 9 is driven to move the entire polyethylene branch pipe 2 in the direction of the arrow at a rotation speed of 100 to 300 rotations / min.
Spin for ~ 360 seconds.

By the rotation of the branch pipe 2 made of polyethylene,
Friction heat is generated on the contact surface between the flange 3 and the outer peripheral surface 1a of the polyethylene main tube 1, and the contact surface is uniformly heated and melted to an extent that it can be melted. Thereafter, the drive of the motor 9 is stopped, and the rotation of the polyethylene branch pipe 2 is stopped. When the rotation of the branch pipe 2 is stopped, the molten portion is solidified and integrated by heat radiation cooling, and the branch pipe 2 is welded to the main pipe 1 in a sealed state. In order to make welding more reliable, the branch pipe 2 may be rotated while being pressed against the main pipe 1, and then the branch pipe 2 may be pressed against the main pipe 1 with a stronger pressure.

After welding the polyethylene main pipe 1 and the polyethylene branch pipe 2, the cutter 11 is propelled from the inside of the other end opening of the polyethylene branch pipe 2, so that the communication hole 1 b is formed in the outer peripheral surface 1 a of the polyethylene main pipe 1. Is formed, and the flow path X of the main pipe 1 and the flow path Y of the branch pipe 2 are communicated.
Thereafter, the rotary welding device 4 is removed from the welded polyethylene main pipe 1 and polyethylene branch pipe 2.

At this time, if a lid 3b for closing the flow path Y is provided beforehand in the vicinity of the opening on the flange portion side of the polyethylene branch pipe 2, friction generated from a molten portion when the polyethylene branch pipe 2 is rotated. Scrap 12 is prevented from scattering, and the friction scrap 12 is sealed in the space defined by the outer peripheral surface 1a and the lid 3b of the polyethylene main pipe 1, so that the friction scrap 12 does not adhere to the inner peripheral surface of the branch pipe. In such a case, when the cutter 11 is propelled from the inside of the other end opening of the polyethylene branch pipe 2, the friction waste 12 falls into the flow path X of the polyethylene main pipe 1 and flows to the downstream side, and It does not cause problems such as clogging the pipeline.

[0022]

As described in detail above, according to the method for branching and joining thermoplastic resin pipes according to the present invention, the flange of the thermoplastic resin branch pipe formed in advance is brought into close contact with the thermoplastic resin main pipe. By rotating the thermoplastic resin branch pipe in the closed state, the joining portion between the thermoplastic resin branch pipe and the thermoplastic resin main pipe is uniformly heated and melted by frictional heat, so that the branch joining can be performed in a sealed state. As a result, it is not necessary to use an adhesive or an expensive heat-generating member such as a heating wire. It keeps the properties and facilitates welding.

Further, according to the branch pipe of the present invention, a lid for closing the flow passage is provided in the vicinity of the opening on the flange side of the thermoplastic resin branch pipe, so that the frictional debris generated by the rotational fusion can be removed in the pipe. Troubles such as dropping on the downstream side and clogging the pipeline of the downstream equipment can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a branch joining method of a thermoplastic resin pipe of the present invention and a branch pipe used in the joining method.

FIG. 2 is a longitudinal sectional view showing a drilling operation state before drilling a cutter according to the present invention.

FIG. 3 is a longitudinal sectional view showing a drilling operation state during cutter drilling of the present invention.

FIG. 4 is a longitudinal sectional view showing a drilling operation state after the cutter drilling of the present invention.

[Explanation of symbols]

1 Thermoplastic main pipe 1a
Outer peripheral surface of main pipe 1b Communication hole 2 Thermoplastic resin branch pipe 3
Flange 3a Contact surface 3b
Lid 4 Rotary fusion device 5
Support arm 6 Cylinder 7
Guide rail 8 Support bar 9
Motor 10 Joint clamp 11
Cutter 12 Friction waste X Main pipe flow path Y
Branch pipe flow path

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hidekazu Hayashi 2nd Daifuku, Kuwana-shi, Mie F-term in Hitachi Metals Co., Ltd. Kuwana Plant 3H019 DA07 GA01 GA06 4F211 AD05 AD12 AD25 AG08 AH43 TA01 TC06 TC11 TD07 TH02 TH18 TN21 TW25

Claims (4)

[Claims] 1. A method of branching and joining a thermoplastic resin branch pipe to a thermoplastic resin main pipe, wherein a flange is integrally formed in advance at one end of the branch pipe, and the flange is formed of the thermoplastic resin. A branch joining method for thermoplastic resin pipes, wherein the main pipe and the branch pipe are welded by frictional heat by pressing against the outer peripheral surface of the main pipe and rotating the branch pipe. 2. A main body and the branch pipe are welded by frictional heat by providing a lid for closing a flow passage near an opening on the flange side of the thermoplastic resin branch pipe and rotating the branch pipe. 3. The heat pipe according to claim 1, wherein a communication hole is formed in an outer peripheral surface of the lid and the main pipe by propelling a cutter from an inside of an opening of the other end of the branch pipe. Branch joining method of plastic resin pipe. 3. A thermoplastic resin branch pipe which is branched and joined to a thermoplastic resin main pipe, wherein a flange is integrally formed at one end in advance, and the flange is formed on an outer periphery of the thermoplastic resin main pipe. A thermoplastic resin branch pipe characterized by being rotationally welded while being pressed against a surface. 4. The thermoplastic resin branch pipe according to claim 4, wherein a lid for closing the flow path is provided near the opening on the flange side.