JPH084974A - Electrically fusible joint - Google Patents

Abstract

PURPOSE:To firmly block one end of a pipe made of olefin based resin and connect an extension to the one end of the pipe by providing a cover at one end of one of receptacles. CONSTITUTION:Receptacles 21, 21 are provided in opposite end of a pipe joint, and electric heating elements 3 are embedded in the inner peripheral surfaces 21 of the receptacles 21. Further, a cover 4 is provided at one end part of one of the receptacles 21. During the connection of a thermoplastic resin pipe, the thermoplastic resin pipe is fitted in the receptacle 21. Then, terminals 31 are connected to a power source so as to be energized. Thus, the outer peripheral surface of the one end of the thermoplastic resin pipe and the inner peripheral surface 22 of an electrically fusible joint 2 are fused together by the heat from the electric heating elements 3, and accordingly, the front end of the pipe line is blocked by the cover 4. In order to connect an extension to the pipe, a thin wall part 41 formed between the cover 4 and the receptacle 21 is cut off so as to remove the cover 4, the receptacle 21 being exposed to the outside, and then, one end part of a thermoplastic resin pipe in inserted in the exposed receptacle 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric fusion joint used for connecting thermoplastic resin pipes. More specifically, the present invention relates to an electric fusion joint in which receiving ports are provided at both ends of a short pipe, and an electric heating element is embedded in an inner peripheral surface of the receiving port.

[0002]

2. Description of the Related Art There are various types of pipe joints for connecting thermoplastic resin pipes. Among them, as described in JP-A-5-164288, a receiving end is provided at the end, and this receiving end is provided. There is known an electric fusion joint in which an electric heating element such as a nichrome wire is embedded on the inner peripheral surface of the. In this electric fusion joint, the end portion of the thermoplastic resin tube is inserted into the receiving port, the electric heating element is energized, and the inner peripheral surface of the receiving port and the outer peripheral surface of the pipe are fused to form a thermoplastic resin tube. Are to be connected.

On the other hand, in many cases where the pipe is constructed halfway and the pipe is to be extended in the future, the tip of the pipe is often temporarily closed at the time of construction of the pipe. In this case, JIS-K-6743 is used.
There is a cap specified in. This cap is attached to the tip of the pipe line, and in the future, the pipe line will be cut by cutting the pipe from the front side of the cap and connecting a new pipe to the end. Also, as an alternative to this cap,
As described in Japanese Utility Model Publication No. 3-25505, there is known a pipe joint in which a lid is provided at one end of a socket to close the socket.

[0004]

The conventional electric fusion splicing joint is an ordinary pipe joint and cannot be used when the tip of the pipe is closed. Also, the caps specified in JIS-K-6743 and the pipe joints described in the above publications can be used when closing the ends of hard pipes such as vinyl chloride resin pipes that are easily bonded, but polyethylene pipes, etc. It is unsuitable for closing the tip of a tube having elasticity that is difficult to bond like the olefin resin tube. That is, in general, when an olefin resin product is bonded with an adhesive, the mechanical strength of this bonded portion is weaker than other parts, so that the olefin resin cap or the pipe joint described in the above publication is attached to the tip of the olefin resin pipe. Even if it is closed with, if the internal pressure of the pipe increases, the pipe expands and the cap or the joint of the pipe joint, which has relatively weak mechanical strength, is peeled off, and the liquid inside leaks from the joint.
Therefore, an object of the present invention is to provide an electric fusion-bonding joint that can be firmly closed even when used when closing the pipe end of an olefin resin pipe, and that is easy to extend the pipe to the tip of this pipe line. Is to provide.

[0005]

The present invention has been made to achieve the above object, and the invention of claim 1 is as follows.
Receptacles are provided at both ends of the short pipe, and in the electric fusion joint in which electric heating elements are embedded in the inner peripheral surfaces of the receptacles at both ends, a lid is provided at the end of one of the receptacles to form the receptacle. It is blocked.

Further, the invention of claim 2 is the electric fusion joint according to claim 1, wherein a stopper protruding at a height substantially equal to the wall thickness of the pipe is provided between the receiving ports of both ends. There is something. The invention according to claim 3 is the electric fusion joint according to claim 1 or 2, wherein a thinned portion is provided between the receiving port and the lid. The material of the electric fusion joint of the present invention may be any material as long as it is fused with the thermoplastic resin pipe to be connected,
Most preferably, the same material as the thermoplastic resin tube is used.

Preferred materials include olefin resins such as polyethylene, polypropylene and polybutene, polystyrene, polyvinyl chloride, polycarbonate and polyphenylene sulfide. In particular,
Olefinic resins are preferred. The electric heating element used in the present invention is one that generates heat when energized, and a resistance wire such as a nichrome wire or an iron chrome wire is suitable.

[0008]

The operation will be described while explaining the method of constructing the electric fusion joint of the present invention. The end of the thermoplastic resin tube at the final portion of the pipe is inserted into the opening of the electric fusion joint, and the electric heating element embedded in the inner peripheral surface of the opening is energized. Then, the inner peripheral surface of the receptacle of the electric fusion joint is melted and fused to the outer peripheral surface of the thermoplastic resin pipe. When the electric fusion joint is fused in this manner, a lid is provided at the end of the receptacle of the electric fusion joint on the non-fusion side, and the receptacle is closed. The part is closed. In addition, since the inner peripheral surface of the electric fusion joint and the outer peripheral surface of the thermoplastic resin pipe are fused and integrated with each other, the thermoplastic resin pipe and the electric fusion joint may be separated firmly and separated from each other. Absent.

In this way, the tip of the pipe is blocked, the fluid passes through the pipe, and even if the thermoplastic resin pipe expands due to the pressure of this fluid, the electrofusion joint is peeled from the pipe. Never. In particular, since an olefin resin such as polyethylene is difficult to adhere but is easily fused, the electric heating element is energized to melt the inner peripheral surface of the receptacle of the electric fusion joint of the present invention and connect it to the olefin resin pipe. Therefore, even if the pipe expands due to the pressure of the fluid passing through the olefin resin pipe, the olefin resin pipe and the electric fusion joint are not separated from each other.

Next, a construction method for extending the conduit whose tip is blocked in this way will be described. First, the front side of the lid provided at one end of the electric fusion joint is cut to remove the lid. Then, the receiving port of the electric fusion joint appears, so that the end of the thermoplastic resin tube is inserted into the receiving port and the electric heating element provided on the inner peripheral surface of the receiving port is energized. Then, the inner peripheral surface is melted by the heat generated by the electric heating element and fused with the outer peripheral surface of the thermoplastic resin tube. It can be easily extended in this way.

According to the present invention, when the pipe is closed or the pipe is extended, the thermoplastic resin pipe is inserted into the receiving port of the electric fusion joint. If the stoppers are provided between the receiving ports at both ends, the end face of the thermoplastic resin pipe can be inserted until it collides with the stoppers, which facilitates the connection work of the thermoplastic resin pipes. Further, in the present invention, the lid is removed when the conduit is extended. However, as in the third aspect of the present invention, when a thinned portion is provided between the receiving port and the lid, It is easy to cut because it is enough to cut the thin part.

[0012]

Next, embodiments of the present invention will be described. 1 and 2 show one embodiment of the present invention. FIG. 1 is an explanatory view showing a cross section of an electric fusion joint, and FIG. 2 is a thermoplastic resin pipe using the electric fusion joint of FIG. FIG. 3B shows a state in which the pipe is connected, (A) is an explanatory view showing a state where the pipe is inserted into the receiving port, and (B) is an explanatory view showing a state in which the electric fusion joint and the pipe are connected FIG. 3 shows a state in which the pipeline is extended, (a) is an explanatory view showing a state in which the lid body is cut, and (b) is an explanatory diagram showing a state in which the pipeline is extended. Is.

1 to 3, reference numeral 1 denotes a thermoplastic resin tube made of polyethylene. Reference numeral 2 denotes a socket-type polyethylene electric fusion-bonding joint. The electric fusion-bonding joint 2 is provided with receiving ports 21, 21 at both ends, and an electric heating element 3 made of a nichrome wire is provided on an inner peripheral surface 22 of the receiving port 21.
Is buried. This electric heating element 3 is a terminal 3
When 1 and 31 are connected to a power source, heat is generated and the inner peripheral surface 22 of the electric fusion joint 2 is melted. The receiving opening 21 is tapered so that the end of the thermoplastic resin tube 1 can be easily inserted into the receiving opening 21.

Reference numeral 4 denotes a lid body provided at one end of the electric fusion joint 2, and the lid body 4 allows one of the receiving ports 21 to be provided.
Is blocked. A thinned portion 41, which is thinned, is provided between the lid 4 and the receiving port 21. Reference numeral 5 is a stopper that protrudes between the receiving ports 21 on both sides at a height approximately equal to the wall thickness of the tube 1.

Next, a method of connecting the thermoplastic resin pipes by this electric fusion joint will be described. As shown in FIG. 2A, the thermoplastic resin tube 1 is inserted into the receiving port 21 provided at the end of the electric fusion joint 2. On this occasion,
Since the stopper 5 is provided between the receiving ports 21 on both sides, the thermoplastic resin pipe 1 is provided with the stopper 5.
Easy to install as it can be inserted up to Next, the terminal 31 is connected to a power source and energized. Then Terminal 3
The electric heating element 3 connected to 1 heats, the inner peripheral surface 22 of the receiving port 21 of the electric fusion joint 2 is melted by this heat, and as shown in FIG. The outer peripheral surface of the end portion 1 and the inner peripheral surface 22 of the electric fusion joint 2 are integrally fused.

When the thermoplastic resin pipe 1 and the electric fusion joint 2 are integrally fused as described above, the end of the pipe line is closed by the lid 4. Further, even if the fluid flows in this pipe line and the thermoplastic resin pipe 1 swells due to the internal pressure of this fluid, the electric fusion-bonding joint 2 is integrally fused and connected very firmly. The pipe 1 and the electric fusion joint 2 will not come off.

Next, a description will be given of how to extend this conduit. As shown in FIG. 3A, the lid 4 and the receptacle 2
The thin portion 41 (the portion indicated by the dotted line) provided between the lid body 4 and 1 is cut to remove the lid 4. In this way, the thin part 4
Since 1 is cut, it is easy to cut. When the lid 4 is removed in this manner, the receiving port 21 is exposed from the inside, so that the end of the thermoplastic resin pipe 1 is inserted into the receiving port 21. At this time, since the stopper 5 is provided,
It is sufficient to insert the thermoplastic resin tube 1 until it is inserted, and it is easy to insert. After that, the terminal 31 is connected to a power source and the electric heating element 3 is energized. Then, the receptacle 21 of the electric fusion joint 2
The inner peripheral surface of is melted, and the inner peripheral surface of the receiving port 21 and the outer peripheral surface of the thermoplastic resin pipe 1 are fused and can be firmly connected. In this way, the conduit can be easily extended.

[0018]

According to the electric fusion joint of the present invention, since the lid is provided at the end of one receiving port to close the receiving port, the thermoplastic resin pipe is inserted into the opening on the opposite side. Then, the ends of the conduit can be closed by fusion. Further, since the inner peripheral surface of the receiving end of the electric fusion joint and the outer peripheral surface of the thermoplastic resin tube can be firmly fused, they will not be separated from this connecting portion. Further, when the lid is removed, the receiving port closed by the lid is exposed. Therefore, by connecting the thermoplastic resin pipe to the receiving port, the pipeline can be easily extended.

Further, when the pipe line is extended in this way, since only the removed lid body needs to be discarded, the amount to be discarded is smaller than the case of cutting the pipe in front of the cap as in the conventional cap. It's convenient. In the present invention, when the stoppers are provided between the receiving ports at both ends as in claim 2, it is convenient because the thermoplastic resin pipe can be inserted up to the stoppers, which makes the construction extremely simple. In the present invention, when the thin portion is provided between the receiving port and the lid as in claim 3, the lid can be easily removed, which is convenient.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is an explanatory view showing a cross section of an electric fusion splicing joint.

FIG. 2 is a view showing a state where a thermoplastic resin pipe is connected using the electric fusion joint of FIG. 1, and (a) is an explanatory view showing a state where the pipe is inserted into the receiving port. , (B) are explanatory views showing a state in which the electric fusion joint and the pipe are connected.

FIG. 3 is a view showing a state in which the pipeline of the present invention is extended, and (a) is an explanatory view showing a state in which the lid is cut;
(B) is an explanatory view showing a state in which the pipeline is extended.

[Explanation of symbols]

1 Thermoplastic Resin Pipe (Polyethylene Pipe) 2 Electric Fusion Joint 21 Receiving Port 22 Inner Surface 3 Electric Heating Element (Nichrome Wire) 4 Lid 41 Thin Wall 5 Stopper

Claims (3)

[Claims] 1. An electric fusion joint in which receptacles are provided at both ends of a short pipe, and electric heating elements are embedded in the inner peripheral surfaces of the receptacles at both ends, and a lid is provided at one end of the receptacle. An electric fusion-bonding joint, characterized in that it is provided and the receiving port is closed. 2. The electric fusion joint according to claim 1,
An electric fusion joint, characterized in that stoppers projecting at a height approximately equal to the wall thickness of the pipe are provided between the receiving ports at both ends. 3. The electric fusion joint according to claim 1 or 2, wherein a thinned portion is provided between the receiving port and the lid body.