JPS62113538A - Connection of pipe - Google Patents

Abstract

PURPOSE:To permit to connect pipes easily at the site of construction while changing the position of connection by a method wherein a core, having a flange whose peripheral rim is bent toward the main body thereof is inserted into the end of the pipe of polyolefin series and the pipe is heated through the core to push it against the core. CONSTITUTION:A core 2 having a flange 2B whose peripheral rim 2A is bent toward the core 2 (shown by an arrow sign P) is inserted into the end 1A of the pipe 1 of polyolefin series and the pipe 1 is heated through the core 2. Subsequently, the core is pushed toward the pipe 1 or, on the contrary, the pipe 1 is pushed toward the core 2 whereby a flare 1B, having a configuration along the inner surface of the flange 2B, is formed by fusion at the end 1A of the pipe 1. After cooling, the pipe 1 is connected to the main body 3 of a pipe fitting through the flare 1B after removing the core 2 or without removing the core 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for connecting pipes, and more particularly to a method for connecting polyolefin pipes that are difficult to connect using adhesives or the like.

C. Prior Art] As is well known, it is extremely difficult to connect polyolefin pipes using adhesives, and they also have low anti-ta elasticity, so it is difficult to connect polyolefin pipes using adhesives, so it is difficult to connect polyolefin pipes using adhesives. It is also almost impossible to connect with an interposed ring configuration.

For this reason, this type of polyolefin pipe is often connected using a special pipe joint using a mechanical structure with a T-ring, as disclosed in, for example, Japanese Patent Application Laid-Open No. 52-120417.

[Problems with conventional technology]

However, since the above-mentioned pipe joint has a complicated structure,
It is expensive, and since metal claws are dug into the polyolefin pipe to connect it to the pipe fitting, the polyolefin pipe is easily damaged, reducing the strength of the pipe connection. Combined with the deformation of the metal claws, there was a drawback that leaks were likely to occur, especially in high-pressure piping.

On the other hand, in order to solve this problem, a method of forming a flange at the end of a polyolefin pipe and connecting it through this flang has been used for some time, but for convenience of piping, it is necessary to cut the pipe midway. In this case, connection will be impossible and versatility will be poor.

[Problems solved by the invention]

In view of the above-mentioned problems, this invention provides a pipe connection method that can easily connect polyolefin pipes, which have been difficult to connect in the past, and also allows pipe connections to be easily made at the construction site by changing the position of the connection part. It was made for the purpose of providing.

[Technology to solve problems]

That is, in the pipe connection method of the present invention, a core having a flange at one end whose peripheral edge is folded back toward the main body is inserted into the pipe end of a polyolefin pipe, the polyolefin pipe is heated through the core, and the By pressing the core toward the polyolefin tube or by pressing the polyolefin tube toward the core, a flare shaped along the inner surface of the flange is formed at the end of the polyolefin tube, and after cooling, the core is removed. The invention is characterized in that the polyolefin pipe is connected using the flared portion as a locking portion with or without doing so.

〔Example〕

Next, the present invention will be explained with reference to examples.

FIG. 1 is a cross-sectional view of a core used to carry out the method of the present invention, and FIGS. 2, 3, 4, and 5 are explanatory cross-sectional views showing the process of the present invention.

In the pipe connection method of the present invention, as shown in FIG.
is inserted as shown in FIG. 2, the polyolefin tube 1 is heated through the core 2, and then, as shown in FIG.
By pressing the core 2 in the direction of the polyolefin yarn tube 1, or conversely, pressing the polyolefin tube l in the direction of the core 2, the tube end IA of the polyolefin tube 1,
Either melt and form a flare IB shaped along the inner surface of the flange 2B, and after cooling, remove the core 2 as shown in FIG.
Alternatively, as shown in FIG. 5, the core 2 can be connected to the joint body 3 via the flare IB without removing it.

In this case, as the joint body 3, a conventional pipe joint is used.

In addition, as the heating means, a heating heater lO is prepared as shown in FIGS. 6 and 7, and this heating heater lO is
Polyolefin pipe 1 with O activated and core fitted
If the flare IB is formed by pressing in the direction of the arrow, construction is easy and convenient.

[Effect]

In general, polyolefin resins have almost no softening range when heated, such as vinyl chloride resins, and quickly become molten when heated to a certain temperature or higher.

This invention takes advantage of this characteristic, and when the core 2 is inserted into the tube end IA of the polyolefin tube 1 and heated, the polyolefin tube 1 melts at a temperature above a certain yield and melts in the axial direction (arrow P ) together with the pressing force of polyolefin pipe 1
A flare IB along the inner surface of the flange 2B is easily formed at the tube end IA.

When this flare IB is cooled and hardened, it becomes a locking piece for pipe connection, and connection can be easily made using a normal pipe joint member.

In addition, polyolefin resins have a melting temperature of 100℃~
Because it is as low as 140°C, the melting temperature can be easily obtained at construction sites.

〔effect〕

As explained above, this invention
When connecting the tube end I, the core 2 is used as a kind of mold.
Since the flare IB is formed on the core 2, it becomes possible to connect the polyolefin pipe l using an ordinary pipe joint using the flare IB as a locking member.
It can be done anywhere, so to speak, and can be easily processed at the construction site.

Furthermore, since the flare IB is formed around the entire circumference of the tube end IA of the polyolefin tube 1, good connection strength can be achieved.

Furthermore, if the core 2 is connected as shown in FIG. 5, the core 2 also serves as a reinforcing member, which contributes to improving the strength of the joint.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a core used to carry out the method of the present invention, and FIGS. 2, 3, 4, and 5 are explanatory cross-sectional views showing the process of the present invention. am r, 5 times 1,3 sales i? Official document (method) February 12, 1985 l, Indication of the case 1985 Patent Application No. 254371 2, Name of the invention Pipe connection method 3, Relationship with the hli correction case Patent applicant address Osaka City 1-2-47 Shikitsu Higashi, Naniwa-ku Name (1
05) Representative Director and President of Kubota Iron Works Co., Ltd.
Kazu Mino Shige 4, Agent 662 Shipping Port January 28, 1986 6, Simplified i1 of drawing 1 subject to amendment. 'Plus Explanation Column 4, Brief Explanation of the Drawings Figure 1 is a sectional view of the core used in carrying out the method of this invention, Figures 2, 3, 4 and 5 are FIGS. 6 and 7 are explanatory sectional views showing the process of the invention, and FIGS. 6 and 7 are explanatory sectional views showing other embodiments.

Claims (1)

[Claims] (1) A core having a flange whose peripheral edge is folded back toward the main body is inserted into the end of the polyolefin pipe, and the polyolefin pipe is heated through the core, and
By pressing the core toward the polyolefin tube or by pressing the polyolefin tube toward the core, a flare shaped along the inner surface of the flange is formed at the end of the polyolefin tube, and after cooling, the core is pressed toward the core. A method for connecting polyolefin pipes, characterized in that the polyolefin pipe is connected by using the flared part as a locking part, with or without removing it.