JPH10274380A - Electric fused joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fused joint wherein even without using a clamp, fusing work can be performed in a condition fixing a resin pipe, also without spreading a gap from a pipe peripheral surface, pipe slipping off can be prevented. SOLUTION: In a fused joint 1 providing a heat zone burying a heating unit in an internal peripheral surface of a pipe socket 11 of a thermoplastic resin-made joint main body and heating the heating unit fused with a resin pipe 3 inserted in the socket 11, in an end part side of the heat zone in the socket 11, a cold zone 13 is provided, in an end part side of the cold zone 13, an annular groove 5 opened in a circumferential direction is provided, a peripheral part of large thickness and an internal peripheral part 15 of thin thickness are formed, in the internal peripheral part 15, a plurality of axial line direction grooves are provided, a plurality of pressing pipes 17 on a circumference are integrally provided with the joint main body 10, in a peripheral part corresponding to the pressing piece 17, a hole passed through in the annular groove 5 from an outer surface is provided, in the through hole, a pressing member is inserted from an outer surface, the pressing piece 17 is pressed, to be diametrically contracted, in an inner surface of the pressing pieces 17, pipe slipping off is prevented from the resin pipe 3 inserted in the pipe socket 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusion joint in which a heating element is buried on an inner peripheral surface used for fusing a thermoplastic resin pipe such as polyethylene or polypropylene.
In particular, the present invention relates to fixing a pipe when a joint and the pipe are fused.

[0002]

2. Description of the Related Art When a fusion joint is used to fuse a thermoplastic resin tube with a thermoplastic resin tube, a resin tube is inserted into a tube socket of the joint, and a current is applied to a heating wire on the inner periphery of the joint. In general, fusion bonding is performed in which a resin at an inner peripheral portion and a resin at an outer peripheral portion of a tube are melted and both are integrally fused. If the tube is not fixed during the welding operation, there is a problem in that the tube is pulled out or bent during the welding operation and fused. For this reason, usually, for example, Japanese Patent Application Laid-Open No.
A resin tube inserted into a joint is fixed using a clamp as disclosed in Japanese Patent No. 34578, and a heating wire inside the joint is energized while the tube is prevented from coming off to fuse the joint and the tube. The method is commonly practiced.

[0003] FIG. 4 disclosed in Japanese Patent Application Laid-Open No. 7-91583 is also shown. For this, push bolts are screwed into the cold zone on the inner peripheral surface of the joint socket,
The push bolt is rotated to press the holding plate at the tip of the push bolt against the outer surface of the tube to prevent the tube from coming off.

[0004]

In the case of using the above-mentioned conventional clamp, if the clamp is removed before the fused portion is not sufficiently cooled after applying heat to the heating wire and fusing, the tube is fused by the external force of the tube. There is a problem that the part is bent or the pipe comes out of the joint. For this reason, the clamp cannot be removed for a long time even after the energization is completed until the fused part is cooled down,
It takes a long time to install and remove the clamp, so a large number of clamps must be prepared in order to sequentially perform the welding work at the piping site, and the welding time is long due to the clamp. There were problems such as complicated construction work.

In the latter type, in which the pipe is prevented from coming off by means of a bolt which is screwed into the end of the receiving port, the gap between the outer peripheral surface of the pipe and the inner peripheral surface of the receiving port of the joint is widened by the pressing of the bolt, and the heat zone of the joint heat zone is increased. Heat transfer to the tube surface by the molten resin is difficult to conduct due to the increase in the gap, and the fusion state of that part becomes insufficient, and the molten resin in the joint heat zone blows out from the gap,
There were problems such as a long fusion time. Further, since a backing plate must be provided below the bolt, there are also problems that the number of components is large and assembly is complicated. The present invention solves the above-mentioned problems, and can perform fusion work in a state where a resin tube is fixed with a simple component configuration without using a clamp, and without expanding a gap with the outer peripheral surface of the tube. It is intended to provide a fusion joint capable of preventing the slippage of the joint.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a heating zone in which a heating element is buried on the inner peripheral surface of a pipe receiving port of a thermoplastic resin joint body, and the heating element is heated and inserted into the receiving port. A fusion joint for fusing with a pipe, wherein a cold zone is provided at an end side of the heat zone in the receptacle, and an annular groove which opens in a circumferential direction is provided at an end side of the cold zone, and An outer peripheral portion and a thin inner peripheral portion are formed, a plurality of axial grooves are provided in the inner peripheral portion, and a plurality of pressing pieces on the circumference are integrally provided with the joint body, and the outer periphery corresponding to the pressing piece is provided. A resin pipe inserted into the through hole from the outer surface into the annular groove, a pressing member is inserted into the through hole from the outer surface to press the pressing piece to reduce the diameter, and the inner surface of the pressing piece is inserted into the pipe receiving opening. This is an electrofusion joint characterized in that the joint is prevented from coming off.

[0007]

Since the present invention has the above construction, after inserting the connecting resin pipe into the pipe receiving port of the joint, the pressing member is inserted from the through hole of the outer peripheral part provided in the cold zone on the end side of the receiving port to thereby insert the inner peripheral part. By pressing the thin pressing piece of the portion, the pressing piece is integral with the joint body and is divided circumferentially in the axial direction, so it is pressed in the axial direction to reduce the diameter and the inner peripheral surface of the pressing piece. The outer peripheral surface of the resin pipe inserted into the pipe receiving port of the joint is pressed and the resin pipe is fixed and prevented from falling off. At this time, since the pressing piece presses the pipe by deformation of the thin inner peripheral portion forming the joint body, the pressing piece is in close contact with the surface of the pipe, so that the gap between the inner peripheral surface of the joint body and the outer peripheral surface of the pipe is reduced. Can be fused. Therefore, the conventional problem caused by the increase in the gap is solved, the fusion can be normally performed in a short time, and the operation can be simplified without using the conventional clamp.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are partial cross-sectional views of an electrofusion joint 1 according to an embodiment of the present invention, in which a thermoplastic resin tube 3 is inserted into a tube receiving port 11 and a pressing piece 17 is bolted by a pressing member 2. This shows a state in which the diameter of the pipe 3 has been reduced to prevent the pipe 3 from coming off. The inner peripheral surface of the joint body 10 has a heat zone 11 in which a heating wire 12 is helically embedded. The end of the heating wire 12 is connected to a connector pin that is embedded in the joint body and protrudes to the outer surface. , Heating wire 1 from outside via connector pin
2 and the heating of the heating wire 12
Is melted, the outer peripheral surface of the tube 3 is heated by the expansion of the molten resin, and the tube and the joint are fused together.

An end portion of the heat zone 11 in which the heating wire 12 is embedded is a cold zone 13. In the cold zone 13, an annular groove 5 which is open at the end face of the joint body 10 is provided to form a thick annular outer periphery. A portion 14 and a thin inner peripheral portion 15 are formed. On the inner peripheral portion 15 side, a plurality of (four in the embodiment) axial grooves 16 are provided in the circumferential direction, and four pressing pieces 17 integral with the joint body are provided on the inner peripheral side of the joint end. The annular outer peripheral portion 14 corresponding to the pressing piece 17 is provided with a screw hole 18 that penetrates from the outer surface through the annular groove, and the bolt 2 is screwed into the screw hole 18.

FIG. 1 shows a pressing piece 17 by pressing the bolt 2.
When the resin pipe 3 is crimped, the pressing piece 17 is a thin movable piece that extends to the end side integrally with the joint main body.
The surface of the resin tube 3 housed inside is fixed by pressing.
In addition, in order to regulate the screwing amount of the bolt 2 to a constant value, a seat where the head of the bolt 2 abuts on the outer surface of the screw hole 18 of the joint body 10 can be formed so that the screw cannot be screwed in more than a predetermined amount. This is effective when the thickness of the joint body 10 is small and the dimension of the outer peripheral portion 14 cannot be sufficiently obtained.

FIG. 3 is a partial sectional view showing another embodiment of the present invention, in which a thermoplastic resin tube 3 is inserted into a tube receiving port 11, and a driving screw 4 serving as a pressing member is mounted to remove the tube 3. This shows the state where the stop is performed. In this embodiment, a straight hole 19 is formed in place of the screw hole 18 of the above-described embodiment, and the pressing member uses a driving screw 4 having a return 41 on the outer surface as shown in FIG. When the head of the screw 4 is driven into the straight hole 19 from the outer peripheral surface with a hammer or the like, the return 41 of the outer peripheral surface of the screw is
Eat into 6. Then, similarly to the above embodiment, the bottom surface of the screw 4 presses the pressing piece 17, and when the end of the screw 4 coincides with the outer peripheral surface of the joint, the driving of the screw is completed and the pipe is fixed. In the above embodiment, the fusion joint 1 that generates heat by the heating wire 12 is replaced with a conductive fiber such as carbon fiber or a laminate thereof, a processed product in the form of a mesh sheet, or a high-frequency induction heating or micro heating. The same applies to a joint that generates heat by wave heating or the like.

In connection, the end of the connecting resin pipe 3 is inserted into the pipe receiving opening 11 of the joint body 10, and then a plurality of screw holes 18 or straight holes 1 provided on the outer peripheral surface of the joint body.
The bolt 2 or the driving screw 4 as a pressing member is inserted into the tube 9 from outside to fix the tube. Next, the electric heating wire 12 in the fusion joint main body is energized from an external controller to heat the heating wire 12 or the heating element in the joint main body is heated by induction heating or microwave heating. The resin is melted and the two are fused. At this time, it is not necessary to remove the pressing members 2 and 4 holding the joint and the pipe, and the welding operation can be performed in a state where the pressing members 2 and 4 are inserted into the screw holes 18 or the straight holes 19. It is convenient because it is buried as it is.

[0013]

According to the present invention, the resin pipe inserted into the joint can be easily and reliably fixed without using a conventional clamp, and the gap between the outer peripheral surface of the pipe and the inner peripheral surface of the joint can be reduced. The fusion can be performed, and the heat is transmitted normally during the fusion, and the fusion work can be performed correctly in a short time. In addition, since it has a simple component configuration, construction work on site can be easily performed, and manufacturing can be also easily performed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a state in which a resin tube is inserted into and fixed to an electric fusion joint according to an embodiment of the present invention.

FIG. 2 is a front sectional view of FIG.

FIG. 3 is a partial sectional view using a pressing member of another embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing a fixing portion to a conventional resin tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric fusion joint 2 Bolt 3 Resin pipe 4 Driving screw 5 Annular groove 10 Joint main body 11 Pipe socket 12 Heating wire 13 Cold zone 14 Annular outer peripheral part 15 Inner peripheral part 16 Axial groove 17 Pressing piece 18 Screw hole 19 Straight hole

Claims (1)

[Claims] 1. A fusion joint in which a heat zone in which a heating element is buried is provided on an inner peripheral surface of a pipe receiving port of a thermoplastic resin joint body, and the heating element is heated to fuse with a resin pipe inserted into the receiving port. A cold zone is provided on the end side of the heat zone in the receptacle, and an annular groove that opens in the circumferential direction is provided on the end side of the cold zone to form an outer peripheral portion of the pressed wall and a thin inner peripheral portion. Then, a plurality of axial grooves are provided in the inner peripheral portion, a plurality of pressing pieces on the circumference are provided integrally with the joint body, and a hole penetrating from the outer surface to the annular groove in the outer peripheral portion corresponding to the pressing piece. Wherein a pressing member is inserted into the through-hole from the outer surface to reduce the diameter of the pressing piece, and the inner surface of the pressing piece stops the resin tube inserted into the tube receiving opening. Fittings.