JP3143834B2 - Piping joint structure - Google Patents

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 pipe joint for vacuum sewage using polyethylene pipes.

[0002]

2. Description of the Related Art Conventionally, pipes for vacuum sewage are mainly connected by fusion (bad welding) of polyethylene pipes or fusion using an electrofusion joint (EF coupler). Is formed by fusing using a bent pipe that has been previously heated and bent or by applying an external force to a polyethylene pipe to bend the pipe.

[0003]

However, when a vent pipe is used, it is difficult to set the pipe according to the situation of the pipe in the field work, so that there are many kinds of vent pipes, and there are problems in production and management. In all the bending operations, the bending limit is 20 times the pipe diameter (20D, D: diameter), so that there is a problem that the curvature of the pipe becomes large and is not suitable for on-site joint work. Further, if the post-heating operation for removing the stress is not performed on the bent portion, the post-heating operation is necessary because it causes a stress crack, and it is not possible to avoid time and labor in this respect.

In order to solve the above-mentioned problems, it has been desired to develop a joint having a flexible portion in the middle of a polyethylene pipe, but it is difficult to bond the polyethylene pipe to the flexible rubber pipe. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a highly airtight piping joint structure in which a flexible rubber pipe is connected to a polyethylene pipe. I do.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for separating a polyethylene pipe and a flexible rubber pipe from each other.
A pipe joint structure integrally connected, the outer diameter of which is approximately equal to the inner diameter of the flexible rubber pipe and the outer diameter of which
A cylindrical portion that is approximately equal to the inner diameter of the
There is a step between the cylinders, and the outer periphery of each cylinder
In addition to having a connecting pipe with a convex part at the fixed position ,
Polyethylene tubes and the flexible rubber pipe end faces flat machined formation, and to form a concave groove for preventing leakage to the outer periphery of the predetermined position from the end face of the polyethylene pipe, the connection pipe one
Fitting insert the square of the cylindrical portion to its end face in a polyethylene pipe reaches the stepped portion, further flexibility to the other of the cylindrical portion of the connecting pipe
Insert the flexible rubber tube into the flexible rubber tube until the cylindrical portion of the connection tube is inserted.Tighten the flexible rubber tube with a hose band. brought into close contact with the resin injection molding on the outer periphery of the polyethylene pipe end and full <br/> Rekishiburugomu tube end comprising
And forming a resin joint .

[0007]

With the above-mentioned structure of the pipe joint, a flexible rubber pipe is connected with good airtightness in the middle of a rigid polyethylene pipe, so that heat is applied to the above-mentioned polyethylene pipe. The pipe can be formed without the need for bending work and post-heating work.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 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 general structure of the present pipe joint is as follows. One end of a stainless steel connection pipe 4 is inserted into one end of a flexible rubber pipe 6, one end of a polyethylene pipe 1 is inserted into the other end of the connection pipe 4, and the outer periphery thereof is inserted. This is a structure in which the resin joint 2 is formed by resin injection molding. Hereinafter, the piping joint structure will be described in detail.

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

The end face of the polyethylene pipe 1 is formed flat, and a groove for mounting an O-ring is formed on the inner circumference at a predetermined position from the end face, and furthermore, it is prevented on the outer circumference at a predetermined position from the end face. Concave groove 1b is formed. Assembly of the pipe joint is performed as follows.

First, a cylindrical portion 4a coated with sealing grease such as silicon grease on the outer periphery of the connection pipe 4 is fitted into the polyethylene pipe 1 until it reaches a substantially central step portion of the stainless steel connection pipe 4, and further connected. The other cylindrical part 4b of the tube
Is fitted 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 fastened with the hose band 5 at the connection tube 4.

Subsequently, a resin joint portion 2 made of resin by resin injection molding is formed on the outer periphery of the polyethylene tube 1 and the flexible rubber tube 6 including the concave groove 1b for preventing the coming off 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-described embodiment, the pipe joint structure in which one end of the flexible rubber pipe is connected to one end of the polyethylene pipe 1 is shown, but the pipe joint structure is an MDPF pipe (medium density polyethylene pipe) as shown in FIG. By connecting the pipe joint structure of the present invention between EF couplers 11 and 11 through EF couplers 10 and 10,
Piping in a small space by the PF pipe can be easily performed.

[0014]

As described above, according to the present invention, the following excellent effects can be obtained. (1) Since the flexible polyethylene pipe is connected to the end of the rigid polyethylene pipe, the number of pipe bending steps can be reduced. (2) A configuration in which a flexible rubber pipe is provided in the pipe enables stress concentration to be dispersed, thereby reducing damage to the pipe and reducing man-hours for post-heating work. (3) Since a flexible rubber pipe is provided in the pipe, the pipe can be provided in a small space, which has been difficult in the past, and the on-site construction is easy 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 smaller.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional view showing a 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]

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

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kiyoshi Sakurai 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Prefecture Ebara Research Institute Co., Ltd. (56) References Full-fledged Open 64-64727 (JP, U) 1984-105679 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 21/00 E03F 3/02 F16L 21/02

Claims (1)

(57) [Claims] 1. A a polyethylene tube and the flexible rubber tubing to a piping joint structure connected together, the cylindrical outer diameter substantially not equal to the inside diameter of the flexible rubber pipe portion
And a cylindrical part whose outer diameter is approximately equal to the inner diameter of the polyethylene pipe
Are integrally formed and have a step between the two cylindrical portions.
At a predetermined position on the outer periphery of the cylindrical portion, a connection pipe having a convex portion is provided , and the end faces of the polyethylene pipe and the flexible rubber pipe are formed into a flat shape, and the end face of the polyethylene pipe is formed from the end face. forming a concave groove for preventing leakage to the outer periphery of the predetermined position, its one of the cylindrical portion of the connecting pipe to the polyethylene tube
Until the end surface of the connection tube reaches the step portion, and further connect the other cylindrical portion of the connection tube to the flexible rubber tube so that the end surface thereof is forward.
The flexible rubber tube is inserted until the cylindrical portion of the connection tube is inserted.
The way tightened with a hose band, to form a further recessed groove and the outer periphery is brought into close contact with the resin injection molding plastic joint of the polyethylene pipe end and the flexible rubber tube end comprises a hose band for the removal prevention A pipe joint structure characterized by the above-mentioned.