JPS61173920A - Method for thermal fusion connection of synthetic resin pipe - Google Patents

Abstract

PURPOSE:To obtain a uniform fusion state over the entire peripheral surface of a pipe by eliminating the protrusion of a molten resin when the pipe is connected to a socket, by thermally fusing the inner surface of a joint receiving opening and the outer surface of a pipe insert opening while the side surface of a washer shaped ring body is pressed to the end surface of the joint receiving opening through a two-split metal clamp jig. CONSTITUTION:A two-split metal clamp jig 3 is fixed to the outer surface of a pipe insert opening 1 at a position leaving an insert length (l) in a joint receiving opening and a washer shaped ring body 4, of which the inner diameter (d) is made slightly larger than the outer diameter R of the pine insert opening 1, is externally fitted to the outer surface of the pipe insert port from the pipe insert opening end 1. Subsequently, the resin of the surface layer parts of the outer surface of the pipe insert opening 1 and the inner surface of a joint receiving port 2 is melted under heating and the pipe insert opening is immediately inserted in the joint receiving opening 2. Next, the inner surface of the aforementioned joint receiving opening 2 and the outer surface of the aforementioned pipe insert opening 1 are thermally fused while the surface 4A of the washer shaped ring body 4 is pressed to the end surface 2' of the aforementioned joint receiving opening 2 through the aforementioned two-split metal clamp jig 3. At time of thermal fusion, the protrusion of the molten resin generated from the fusion interface of the outer surface of the pipe insert opening 1 and the inner surface of the joint receiving opening but blocked by the washer shaped ring body 4 to be brought to a pressure collapsed state.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for heat-sealing and connecting synthetic resin pipes, and more specifically, by inserting a tube socket into a joint socket, connecting the inner surface of the socket and the socket. This invention relates to an improvement in a method of fusing and connecting external surfaces by heat fusion.

2. Description of the Related Art Conventionally, when connecting synthetic resin pipes, the inner surface of a joint socket and the outer surface of a pipe insertion port are sometimes connected by heat fusion.

However, when performing heat fusion with the joint socket B and pipe socket C, the heat melt resin A is heated between the joint socket B and the pipe socket C as shown in Figure 5. The resin protrudes from the fused interface, and as a result, a bead D and a notch E of the molten resin are formed on the joint socket end face B'.

Of these, the notch E has an acute-angled cross-sectional shape as shown in the figure, so when a bending force is applied to the connection part,
There was a problem in that stress was concentrated and the connection part was broken at this point.

In addition, when connecting pipes by heat fusion, in order to correct the roundness of the connecting pipe, regulate the insertion length, and hold the pipe, a split clamp fitting (also known as a cold ring) as shown in Figure 6 is used. This two-piece clamp fitting F is bottom-fitted to the outer periphery of the pipe insertion port C using the pipe fitting F, and then fitted into the joint socket B.

In this case, the clamp fitting F side face F' and the joint socket end face B'
The hot melt resin A is prevented from protruding at the part where the two are in close contact with each other, and therefore the bead D and notch E described above do not occur. So, Pidro 1notsuchi E
cannot be prevented from occurring.

Even if the notch E is small, if it is formed, a crack will progress from there due to stress concentration, and the problem is that it is not very effective in improving the durability of the connection part.

Problems to be Solved by the Invention In view of the above-mentioned problems, this invention eliminates the protrusion of molten resin when joining a tube to a socket by heat fusion, and creates a uniform fused shape over the entire outer circumference of the tube. The purpose of this work was to provide a heat fusion splicing method for synthetic resin pipes.

Technique that led to solving the problem The method of heat-sealing and connecting synthetic resin pipes of the present invention fixes a bifurcated clamp fitting on the outer surface of the pipe insertion port at a position that leaves a length for insertion into the joint socket, and Fit a washer-like ring body having an inner diameter hole slightly larger than the outer diameter of the tube insertion port from the tube insertion end, heat and melt the inner surface of the joint socket and the outer surface of the tube insertion port, and then insert the vaginal tube insertion port into the joint socket. and heat-sealing the inner surface of the joint socket and the outer surface of the pipe socket while pressing the side surface of the washer-like ring body against the end surface of the joint socket through the split clamp fitting. It is.

Operation Next, the present invention will be explained with reference to figures showing the process of implementation.

FIGS. 1 to 3 are explanatory diagrams showing the process of implementing this invention.

In implementing the method of the present invention, first, the two-split clamp fitting 3 is fixed to the outer surface of the tube insertion tube at a position that leaves an insertion length l into the joint socket 2, and the tube insertion end portion is A washer-like ring body 4 whose inner diameter d is slightly larger than the outer diameter R of the tube insertion port is fitted onto the outside, and then the shallow layer resin on the outer surface of the tube insertion port 1 and the inner surface of the joint socket 2 is heated and melted. ,right away,
As shown in FIG. 2, it is inserted into the joint socket 2, and then, as shown in FIG. End face 2
', the inner surface of the joint receptacle 2 and the outer surface of the tube insertion bay are thermally fused.

At this time, since the pipe insertion port 1 and the split clamp fitting 3 are firmly attached, when the specie ring body 4 is pressed, the pipe insertion port 1 is also pushed into the joint socket 2 and fixed. Needless to say, it is.

During this heat fusion, molten resin protrudes from the fused interface between the outer surface of the tube insertion port 1 and the inner surface of the joint socket 2, but this is blocked by the washer-like ring body 4 and is crushed as shown in FIG. (5 in the figure). Further, due to the washer-like ring body 4, the above-mentioned crushing portion occurs over the entire circumference of the tube.

Therefore, no notches, which would cause a decrease in the strength of the bonded portion, occur around the entire circumference of the tube.

In the above description, the washer-like ring body 4 is fitted around the outer periphery of the pipe socket 1 and has an inner diameter that allows it to move along the axial direction on the outer periphery. It is made equal to or slightly smaller than the outer diameter, and the thickness M is also made as thin as possible, although it is related to strength.

The washer-like ring body 4 is made of a synthetic resin that can withstand the melting temperature of the resin, or a hard material such as metal or ceramic.

Example Next, embodiments of the invention will be described.

Prepare a synthetic resin tube inlet with an outer diameter of about 27μ and an inner thickness of 2.7 fins, and a socket with a socket capable of receiving the synthetic resin tube inlet. , Fix the two-split clamp fitting in a position that leaves about 16R11 of insertion length into the socket, and then attach a metal washer-shaped ring body with an inner hole diameter of 27.5 m, an outer diameter of 30 mm, and a thickness of 1.5 mm. Fit it on the outside, heat and melt the inner surface of the socket and the outer surface of the socket, immediately push the socket into the socket, press the washer-shaped ring body onto the end face of the socket via the split clamp fitting, and cool and harden. I let it happen.

In addition, we have prepared two types of connections: one that does not use a washer-like ring body at all and is connected only with a two-split clamp fitting, and one that connects without a washer-like ring body and a two-split clamp fitting. A bending test was conducted on the Example and the comparative example of Niga, and it was found that in the Example, the outer periphery of the tube insertion port near the joint was bent and deformed before the joint broke due to bending. In all of the comparative examples, the outer periphery of the pipe insertion port along the end face of the joint socket was broken in a ring shape.

Effects Since the present invention is constructed as described above, when a socket and a pipe are connected by heat fusion, the notch is completely prevented from being formed by the protruding molten resin, and the washer-like ring body is also formed by the molten resin. Since it can be bonded to the end of the socket, the bonded portion can be reinforced by this, and the strength of the connection portion can be significantly increased.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams showing the process of the present invention, FIG. 4 is an enlarged cross-sectional view of a joint portion obtained by the method of the present invention, FIG. 5 is an explanatory cross-sectional view of a conventional example, and FIG. The figure is a perspective view of the two-split clamp fitting. rnoE 3J 75m 71;m F/C penalty W)

Claims (1)

[Claims] (1) When connecting the inner surface of the joint receptacle and the outer surface of the pipe insertion port by heat-sealing, fix the split clamp fitting in a position that leaves enough insertion length into the joint receptacle on the outer surface of the pipe receptacle. At the same time, a washer-like ring body having an inner diameter hole slightly larger than the outer diameter of the pipe socket is fitted from the pipe socket end, and after heating and melting the inner surface of the joint socket and the outer surface of the pipe socket, the pipe socket is inserted into the joint socket. The tube is inserted into the mouth, and the side surface of the washer-like ring body is pressed against the end surface of the joint socket via the split clamp fitting, and the inner surface of the joint socket and the outside surface of the pipe socket are fused together. Heat fusion splicing method for synthetic resin pipes.