JPH05203084A - Piping joint structure - Google Patents

Abstract

PURPOSE:To improve piping execution workability by inserting a connecting pipe fitted over a connecting end part of each pipe, thereafter fastening the periphery of a rubber pipe with a hose band, and injection molding a resin joint part to a connection part total unit, in the case of connecting the polyethylene-made pipe to the flexible rubber pipe. CONSTITUTION:In the case of connecting a vacuum sewer pipe using a polyethylene-made pipe 1, a flexible rubber pipe 6, with a steel-made core wire helically buried in the inside, is used when the pipe is connected in its curved part. There is prepared a connecting pipe 4 made of stainless steel or the like formed of a cylindrical part with an external diameter of one cylindrical part 4b almost equal to an internal diameter of the rubber pipe 6 and an external diameter of the other cylindrical part 4a almost equal to an internal diameter of the polyethylene-made pipe 1. In this connecting pipe 4, after fitting each cylindrical part 4a, 4b of the pipe to a connecting end part of each pipe 1, 6, the periphery of the rubber pipe 6 is fastened by a hose band 5 in a part of the connecting pipe 4. Thereafter, a resin joint part 2 is formed by injection molding in the periphery of each pipe 1, 6 containing the hose band 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint structure, and more particularly to a pipe joint structure suitable as a joint for vacuum sewer pipes using polyethylene pipes.

[0002]

2. Description of the Related Art Conventionally, vacuum sewage pipes have been connected mainly by fusion of polyethylene pipes (bad welding) or fusion using an electrofusion joint (EF coupler). Is formed by fusion using a bent pipe that has been bent by applying heat in advance or by bending the polyethylene pipe by applying an external force.

[0003]

However, when the vent pipe is used, it is difficult to set it according to the situation of the pipe at the site work, and there are many kinds of the vent pipe, which causes problems in manufacturing and management. In all bending work, the bending limit is 20 times the pipe diameter (20D, D: diameter), so there was a problem that the curvature of the pipe was large and it was not suitable for field joint work. Further, if the post-heating work for stress removal is not performed on the bent portion, the post-heating work is necessary because it causes stress cracks, and it is unavoidable that this also requires time and labor.

Therefore, as a method for solving the above problems, it is desired to develop a joint in which a flexible portion is provided in the middle of a polyethylene pipe, but it is difficult to bond the polyethylene pipe and the flexible rubber pipe. There is a problem.

The present invention has been made in view of the above problems, and an object thereof is to eliminate the above problems and to provide a highly airtight pipe joint structure in which a flexible rubber pipe is connected to a polyethylene pipe. To do.

[0006]

In order to solve the above problems, the present invention provides a pipe joint of a polyethylene pipe and a flexible rubber pipe, one outer diameter of which is substantially equal to the inner diameter of the polyethylene pipe and the other outer diameter A stainless-steel connecting pipe made of a cylindrical portion having an inner diameter equal to the inner diameter of the flexible rubber pipe is prepared, and end faces of the polyethylene pipe and the flexible rubber pipe are flattened and formed at a predetermined position from the end face of the polyethylene pipe. A recessed groove is formed on the outer periphery to prevent slipping out, and a cylindrical portion with a sealing grease applied to the surface of the connecting pipe is provided with a groove on the inner surface. Insert until it reaches, tighten the flexible rubber tube at the connecting tube with a hose band,
Furthermore, a resin-made resin joint portion is formed by resin injection molding on the outer periphery of a polyethylene tube including a recessed groove for preventing removal and a hose band and a flexible rubber tube.

[0007]

With the above-described structure of the pipe joint, the flexible rubber pipe is connected in the middle of the rigid polyethylene pipe with good airtightness. Therefore, heat is applied to the polyethylene pipe as described above. The piping can be done without the need for bending work and post-heating work.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. 1 is a sectional view showing a pipe joint structure of the present invention, FIG. 2 is a sectional view of a connecting pipe, and FIG. 3 is a sectional view of a polyethylene pipe. In FIG. 1, 1 is a polyethylene pipe, 6
Is a flexible rubber tube. The schematic structure of the present pipe joint is as follows. One end of a stainless steel connection pipe 4 is inserted into the end of the flexible rubber pipe 6, one end of the polyethylene pipe 1 is inserted into the other end of the connection pipe 4, and the outer peripheral portion thereof is inserted. This is a structure in which the resin joint portion 2 is formed by resin injection molding. The present pipe joint structure will be described in detail below.

The flexible rubber tube 6 is a flexible rubber tube in which a steel core wire 6a is spirally inserted and which has strength against external pressure and is flexible. The end surface of the flexible rubber tube 6 is in a cut state. As shown in FIG. 2, the connecting pipe 4 is a stainless-steel pipe in which cylindrical portions 4a and 4b are integrally formed, and convex portions 4c and 4c 'are formed on a predetermined outer periphery of the cylindrical portion 4a. There is.
The outer diameter of one cylindrical portion 4a of the connecting pipe is the polyethylene pipe 1
And the inner diameter of the other cylindrical portion 4b is formed to be substantially equal to the outer diameter of the flexible rubber tube 6.

The end face of the polyethylene pipe 1 is formed into a flat shape, a groove for mounting an O-ring is formed on the inner periphery at a predetermined position from the end face, and the outer periphery at a predetermined position from the end face is prevented from coming off. A concave groove 1b for use is formed. Assembly of the pipe joint is performed as follows.

First, the cylindrical portion 4a coated with a sealing grease such as silicon grease on the outer periphery of the connecting pipe 4 is fitted into the polyethylene pipe 1 until it reaches a step portion in the center of the stainless connecting pipe 4, and is further connected. The other cylindrical portion 4b of the tube
Is inserted into the flexible rubber tube 6 until both ends are close to each other, and the outer periphery of the flexible rubber tube 6 is tightened with the hose band 5 at the connecting tube 4.

Subsequently, a resin joint portion 2 made of resin is formed by resin injection molding on the outer periphery of the polyethylene pipe 1 and the flexible rubber pipe 6 including the recessed groove 1b for preventing slippage and the hose band 5.
To form.

The O-ring 8 is not always necessary and may be omitted in some cases. Further, in the above embodiment, the pipe joint structure in which one end of the polyethylene pipe 1 is connected to one end of the flexible rubber pipe is shown. The pipe joint structure is, as shown in FIG. 4, MDPF pipe (medium density polyethylene pipe). By connecting the pipe joint structure of the present invention via EF couplers 10 and 10 between 11 and 11, MD
Piping in a small space with a PF tube is easy.

[0014]

As described above, according to the present invention, the following excellent effects can be obtained. (1) Since the flexible flexible rubber pipe is connected to the end of the rigid polyethylene pipe, the number of bending steps of the pipe can be reduced. (2) Since the flexible rubber tube is provided in the pipe, it is possible to disperse the stress concentration, reduce damage to the pipe, and reduce the number of post-heating operations. (3) Since the flexible rubber tube is provided in the pipe, it is possible to perform piping in a small space, which was difficult in the past, and it is easy to carry out on-site construction and the number of steps can be reduced. (4) Since the bending limit of the pipe can be made smaller than that of the conventional example, the curvature of the pipe can be made small.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a pipe joint structure of the present invention.

FIG. 2 is a cross-sectional view showing the shape of a connecting pipe.

FIG. 3 is a cross-sectional view showing the shape of a polyethylene pipe.

FIG. 4 is a diagram showing an example of piping using the piping joint structure of the present invention.

[Explanation of symbols]

 1 Polyethylene pipe 2 Resin joint part 4 Connection pipe 5 Hose band 6 Flexible rubber pipe

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kiyoshi Sakurai 4-2-1 Motofujisawa, Fujisawa City, Kanagawa Prefecture EBARA Research Institute

Claims (1)

[Claims] 1. A pipe joint structure in which a polyethylene pipe and a flexible rubber pipe are integrated, wherein one outer diameter is substantially equal to the inner diameter of the flexible rubber pipe and the other outer diameter is the inner diameter of the polyethylene pipe. A connecting pipe consisting of substantially equal cylindrical parts is prepared, the end faces of the polyethylene pipe and the flexible rubber pipe are flattened and formed, and a recessed shape for preventing slipping out is provided at a predetermined position from the end face of the polyethylene pipe. A groove is formed, the cylindrical portion of the connecting pipe is inserted into the polyethylene pipe until the step portion of the cylindrical portion is reached, and the other end of the connecting pipe is inserted into the flexible rubber pipe until both ends are close to each other. The flexible rubber tube at the connecting tube with a hose band, and the polyethylene tube including the concave groove and the hose band for preventing slippage and the flap. A pipe joint structure characterized in that a resin joint portion made of resin is formed by resin injection molding on the outer periphery of a flexible rubber pipe.