JP2010261557A - Method for connecting resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for connecting a resin pipe capable of preventing easy breakage at a root between the resin pipe and a pipe joint side connection port heat-fused to each other. <P>SOLUTION: The connection structure joining the connection port 4 of a resin pipe joint to the pipe end of the resin pipe fitted into the connection port by heat fusion eliminates the breakage of the resin pipe at the root to the connection port of the resin pipe joint. A ring collar 3 is thereby insert-fitted to the pipe end side of the resin pipe, and the resin pipe is heat-fused to the connection port of the resin pipe joint together with the ring collar. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin pipe connection method, and more particularly, to a resin pipe connection method in which a pipe end of a resin pipe is internally fitted to a connection portion of a joint member, and the fitting portion is integrated by thermal fusion. .

  Conventionally, when a synthetic resin pipe and a synthetic resin pipe joint are heat-sealed and joined, the joint root part often breaks during use due to an external force from the lateral direction. One of the causes of the breakage of the joint root portion is considered to be stress concentration on the outer end portion of the connection port portion of the resin pipe.

  Therefore, as a means of suppressing breakage of the joint root portion, a metal or synthetic resin reinforcing tube having an outer diameter that matches the inner diameter of the tube is inserted in advance into the tip portion of the synthetic resin tube to be inserted into the joint member, There has been proposed one that is effectively reinforced from the inside (Patent Document 1).

  In addition, a collar portion having a diameter larger than that of the connection port portion is extended to the connection port portion of the resin pipe fitting main body, and between the collar portion and the resin pipe in which the tube end is fitted in the connection port portion. There has also been proposed a resin receiving space in which a molten resin generated at the time of heat fusion can protrude (Patent Document 2).

JP 2003-148679 A Japanese Patent Application Laid-Open No. 11-201362

  In the case where the reinforcing pipe is inserted into the tip of the synthetic resin pipe, there is a problem in durability when the reinforcing pipe is made of a different material. There was also a problem of getting into the piping. On the other hand, in the case where the resin receiving space is formed between the collar portion formed by extending the connection port portion and the resin tube, the melted resin flows into the inside of the resin receiving space. Depending on the amount of the molten resin, variation occurs in the moment arm length when a bending force acts on the resin tube, and it is difficult to obtain a stable strength.

  The present invention has been made paying attention to such points, and a resin pipe connection method that does not easily break at the base portion between the joint portion on the pipe joint side and the resin pipe that are heat-sealed to each other. The purpose is to provide.

  In order to achieve the above-mentioned object, the present invention is configured such that a ring rod is inserted into a portion near the pipe end of the resin tube, and the resin tube is heat-sealed to the connection port portion of the pipe joint together with the ring rod. It is characterized by that.

  In the present invention, the ring rod inserted in the portion near the pipe end of the resin pipe is thermally welded to the connection port portion of the pipe joint together with the resin pipe, so that the outer peripheral surface portion of the resin tube and the inner periphery of the ring rod An unfused groove-like space portion is formed between the surface portion and the resin tube, even if bending force is applied, between the outer peripheral surface portion of the resin tube and the inner peripheral surface portion of the ring rod. Since the bending size of the formed groove-like space portion is restricted by the size of the groove-like space, the bending force hardly acts on the root portion of the resin tube, so that breakage at this root portion can be prevented. . As a result, workability during construction can be improved.

It is a longitudinal cross-sectional view of the resin pipe joint part to which this invention is applied. It is a figure which shows the connection procedure of a resin pipe. It is sectional drawing which shows the shape of a ring cage.

This pipe connection structure includes a pipe joint (1) integrally formed of polybutene resin, a pipe body (2) made of polybutene resin, and a ring rod (3) to be inserted near the tip of the pipe body (2). It consists of.
The illustrated pipe joint (1) is a different diameter T-shaped joint configured to branch out a small-diameter pipe, and each connection port (4) is formed in a stepped shape at each end. The inner peripheral surface portion (5) of the connection port portion (4) is formed in a tapered surface that spreads outward. Further, the distal end portion (6) of the tube (2) to be fitted into the connection port (4) is heat-sealed so as to form a tapered surface.

  The ring rod (3) mounted near the tip of the pipe body (2) is formed of the same kind of resin as the pipe joint (1) and pipe body (2), that is, polybutene resin, and its outer diameter is pipe. The joint (1) is formed to have the same diameter as the outer diameter of the connection port (4), and the inner diameter is formed to a diameter that can be loosely fitted to the outer peripheral surface portion of the tube (2).

In the pipe connection described above, the ring rod (3) and the pipe body (2) are joined to the pipe joint (1) by the procedure shown in FIG.
That is, as disclosed in FIG. 2A, a pipe joint (1), a ring rod (3), and a tube body (2) are prepared, and the ring rod (3) is attached to the connecting end portion of the tube body (2). It is inserted (FIG. 2 (b)). Next, a depth gauge (10) is attached to the pipe end side of the ring rod (3) to determine the mounting position of the ring rod (3) (FIG. 2 (c)), the ring rod (3) and the pipe The relative position of the ring rod (3) with respect to the tube (2) is fixed by gripping the body (2) with a cold ring (11) constituted by a vice plier (FIG. 2 (d)).

  While holding ring ((3) with cold ring (11), remove depth gauge (10) from tube (2), insert end of tube (2), and connection port of fitting (1) (4) is heated for a predetermined time by the hot melt heater (12) (FIG. 2 (e)). Insert the insertion end of the heated tube (2) into the connection port (4) of the pipe fitting (1), hold it in a crimped state, and integrate the two (FIG. 2 (f)). .

  The molten resin overflowing when the pipe (2) and the pipe joint (1) are joined concentrates on the contact surface between the connection port (4) of the pipe joint (1) and the ring rod (3). The gap (7) hardly flows into the gap (7) formed between the outer peripheral surface of the body (2) and the inner peripheral surface of the ring rod (3). In addition to acting as a deformation absorption margin when force is applied, the thickness and length of the gap (7) suppresses the deformation amount of the tube (2), and the tube joint (2) ( Large stress is not concentrated on the connection end of 1).

  As shown in FIG. 3, the shape of the ring rod (3) is that the front and rear end surfaces and the inner peripheral surface are orthogonal to each other (FIG. 3a), and the front and rear end portions of the inner peripheral surface are chamfered at 45 degrees. It may be a thing (FIG. 3b) or a thing (FIG. 3c) in which the front and rear ends of the inner peripheral surface are formed in an arc shape. Further, the ring rod (3) may be chamfered only at the front end portion or the rear end portion (FIG. 3d) or formed in an arc shape (FIG. 3e), or may be inclined on the outside of the rear end portion. Good (Fig. 3f). As a result, further prevention of the molten resin overflowing during joining into the gap or prevention of buckling strength at the time of bending at the outer end of the ring rod (3) is achieved.

  When connecting a polybutene resin pipe with an inner diameter of 13 mm and a length of 200 mm to the small diameter portion of a polybutene resin-made T-shaped joint (16 x 13), an annular of 0.5 mm between the outer circumference of the polybutene resin pipe A polybuden resin pipe and a polybutene resin made of different diameter T-shaped joints are assembled in a state where a ring with a thickness of 5 mm with space is inserted, and the fused pipe is parallel to the penetrating shaft core of the T-shaped pipe. Table 1 shows the results when a predetermined tensile load was applied in the direction until an abnormality occurred in the connecting portion.

Comparative example

  As a comparative example, a polybutene resin pipe and a polybutene resin made of different diameter T-shaped joints were assembled without using a ring rod, and the fused parts were abnormal in the direction parallel to the T-tube through-shaft core. Table 2 shows the results in the case where a predetermined bending tensile load is applied until the occurrence of.

  As a result, as shown in the present invention, when the ring rod is inserted into the tube body and the tube body is fused to the connection port portion of the pipe joint, there is an abnormality in the connection portion compared to the case where the ring rod is not used. It can be seen that the load until generation is improved by about 5.2 times, and the displacement is increased by about 1.1 times.

  INDUSTRIAL APPLICABILITY The present invention can be used for fusion connection between a hot-melt resin pipe joint and a pipe material.

  DESCRIPTION OF SYMBOLS 1 ... Resin pipe joint, 2 ... Resin pipe body, 3 ... Ring rod, 4 ... Connection port part of resin pipe joint, 5 ... Inner peripheral surface in connection port part, 6 ... The part near the front-end | tip of a pipe body, 7 ... Gap, 10 ... Depth gauge, 11 ... Cold ring, 12 ... Hot melt heater.

Claims (2)

  In joining the connection port part of the resin pipe joint and the pipe end of the resin pipe fitted inside the connection port part by heat induction, a ring rod is inserted into the part near the pipe end of the resin pipe, A resin pipe connecting method, wherein the resin pipe is heat-sealed to the connection port of the pipe joint together with the ring rod.   The method for connecting resin pipes according to claim 1, wherein the pipe joint and the resin pipe connected thereto are made of polyten resin.

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