JPH09314668A - Method of joining synthetic resin pipes - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To prevent the occurrence of beads on the inner wall surface of a joint part, as well as to join the pipe to the joint port without leaving stress on the joint port. It is intended to provide a joining method. SOLUTION: An inner peripheral surface of a receiving port of a synthetic resin joint, which is tapered toward the inner side, and an outer peripheral surface of a receiving port fitting portion of a synthetic resin pipe are heated and melted. Made of synthetic resin that fits the socket fitting part of the synthetic resin pipe into the socket of the joint while keeping the heating and melting state, and cools and solidifies the molten part to integrate the synthetic resin pipe into the joint. In the pipe joining method, prior to heating and melting, the outer peripheral surface of the inlet fitting portion of the synthetic resin pipe is cut so as to be reduced in diameter at the same or smaller diameter as the inner peripheral surface of the inlet. I decided to do it.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for joining synthetic resin pipes.

[0002]

2. Description of the Related Art Conventionally, a synthetic resin pipe (hereinafter referred to as "resin pipe") has been made without using an adhesive and a synthetic resin joint (hereinafter referred to as "resin pipe").
As described in Japanese Patent Application Laid-Open No. 61-152428, a fitting portion of a resin pipe and a fitting socket are disclosed as a method of fitting and integrating with a socket of "joint"). , Heating by a heating element (heater face) having a shape that fits the socket fitting part and the socket of the joint, respectively,
A method is employed in which the receiving port fitting portion is fitted into the receiving port while maintaining this molten state, and the molten portion is cooled and solidified to join the resin pipe and the joint.

However, according to this conventional method, there is a possibility that, after joining, hydraulic fracture occurs at a level considerably lower than the hydraulic strength of the joint alone or the resin pipe alone at the joint.

That is, in the conventional method, as shown in FIG. 4, the receiving port 101 of the joint 100 is gradually reduced in diameter toward the inner side, while the pipe end 2 of the resin pipe 200 is tapered.
Since 01 has a uniform outer diameter that is chamfered, a large load is applied to the inner wall surface of the receiving port 101 as the pipe end of the resin pipe 200 enters the depth of the receiving port, and after bonding, The stress remains in the joint 100.

Therefore, even if the water pressure is low, the destruction may occur.

Further, according to the conventional method, since the receiving port 101 has a smaller diameter toward the inner side, as the pipe end 201 of the resin pipe 200 is inserted toward the rear side of the receiving port 101, the receiving port 101 is inserted. If the inner wall surface of the resin is scraped and pushed to the back side and the insertion length of the resin pipe 200 is too long, there is a possibility that a bead, which is a source of viable bacteria, may be generated on the inner wall surface of the joint.

[0007]

In view of such circumstances, the present invention makes it possible to join a pipe to a socket without leaving stress on the socket of the joint, and to form a bead on the inner wall surface of the joint. It is an object of the present invention to provide a method for joining synthetic resin pipes that can prevent the occurrence of the same.

[0008]

In order to achieve such an object, a method for joining synthetic resin pipes according to the invention of claim 1 (hereinafter referred to as "joining method of claim 1").
Is the inner peripheral surface of the receiving end of the joint made of synthetic resin, which is tapered toward the back side, and the outer peripheral surface of the receiving port fitting part of the synthetic resin pipe. While maintaining the state, a synthetic resin pipe in which the synthetic resin pipe is formed by fitting the synthetic resin pipe fitting part into the synthetic material fitting pipe, cooling and solidifying the melting part In the joining method, prior to heating and melting, the outer peripheral surface of the socket fitting portion of the synthetic resin pipe is cut so as to be reduced in diameter at the same or smaller diameter as the inner peripheral surface of the receptacle. I chose

On the other hand, the method of joining synthetic resin pipes according to the invention of claim 2 (hereinafter referred to as "joining method of claim 2") is such that the joint of synthetic resin is tapered toward the inner side. After heat-melting the inner peripheral surface of the receiving port that shrinks in a circular shape and the outer peripheral surface of the receiving port fitting portion of the synthetic resin pipe, while keeping this heating and melting state, the receiving port fitting of the synthetic resin pipe is performed. Part of the joint is fitted into the receiving port of the joint, the molten portion is cooled and solidified to integrate the synthetic resin pipe into the joint, in the method of joining a synthetic resin pipe, a reduced diameter angle of the inner peripheral surface of the receiving port. Fit the socket fitting part of the synthetic resin pipe into a cylindrical heating element that reduces the diameter by the same or smaller diameter, and heat and melt the fitting part at the same time to shape the inner surface of the heating element. I decided to do it.

In the construction of the joining method according to the above-mentioned claims 1 and 2, the material of the joint and the pipe is not particularly limited as long as it is a resin material having thermoplasticity. For example, polyvinyl chloride, polyethylene, polypropylene, and Examples of the material include polyethylene mixed with a thermosetting resin, and it is preferable that the joint and the pipe are made of the same material in consideration of fusion bondability.

Further, the fact that the diameter reduction angle of the receiving port fitting portion of the pipe is smaller than the diameter reduction angle of the receiving port is not particularly limited as long as it is tapered, but the diameter reduction of the receiving port is possible as much as possible. It is preferable to be close to the corner.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings. 1 and 2 show an embodiment of the joining method according to claim 1 in the order of the steps. First, as shown in FIG. 1 (a), this joining method is performed by cutting the pipe end portion 11 of the resin pipe 1 to determine whether the diameter reduction angle of the socket 21 of the joint 2 shown in FIG. 1 (c) is the same. The resin fitting 1 is provided with the socket fitting portion 12 that is reduced in diameter toward the pipe end with a small diameter reduction angle.
It is formed at the end of '.

Next, the heating element 3 shown in FIG. 1 (a) is heated to the melting temperature of the processed resin pipe 1 ', and as shown in FIG. 1 (b), the socket fitting portion of the processed resin pipe 1'. The inlet fitting portion 12 of the resin pipe 1 is fitted into the concave portion 31 of the heating body 3 having a tapered surface with the same diameter reduction angle as 12 to melt the outer peripheral surface of the receptacle fitting portion 12. At the same time, as shown in FIG. 1 (c), the heating element 4 is heated to the melting temperature of the joint 2 and the convex portion 41 of the heating element 4 having a tapered surface with the same diameter reduction angle as the receiving opening 21 of the coupling 2 is received. 21 and the inner peripheral surface of the receiving port 21 is melted.

Then, the heating element 3 and the heating element 4 are removed from the processed resin tube 1'or the joint 2, respectively, and the inner peripheral surface of the receptacle 21 and the outer peripheral surface of the receptacle fitting portion 12 are kept in a molten state. In the meantime, as shown in FIG.
2 is fitted, the molten portion is cooled and solidified, and the processed resin pipe 1 and the joint 2 are fused and integrated.

As described above, according to this joining method, at the time of insertion into the receiving port 21, whether the receiving port fitting portion 12 of the processed resin pipe 1'has the same diameter reduction angle of the receiving port 21 toward the pipe end. Since the diameter is reduced at a small diameter reduction angle, the occurrence of stress due to the diameter expansion in the joint 2 at the time of joining is reduced, and the hydraulic strength of the joint portion can be set to the synthetic resin pipe 1 or the joint 2 or more. Further, since the processed resin pipe 1 ′ does not scrape the molten portion of the receiving port 21 of the joint 2 at the time of joining, it is possible to prevent the generation of beads which are a source of viable bacteria.

FIG. 3 shows an embodiment of the joining method of claim 2 in the order of steps. This joining method starts with
As shown in FIG. 3 (a), the heating element 3 is heated to the melting temperature of the resin tube 1, and as shown in FIG. 3 (b), the tube end of the resin tube 1 is directly fitted into the recess 31 of the heating element 3. In addition, the joining method is the same as the joining method described above except that the outer peripheral surface of the tube end portion of the resin tube 1 is melted, and the resin tube 1 is molded so as to follow the inner surface shape of the recess 31.

That is, this joining method has the same effects as the above joining method, and at the same time, the pipe end portion of the resin pipe 1 is heated and melted by the heating body 3, and at the same time the pipe end portion is formed along the receiving port 21. It is designed to transform into
Good workability with no need for cutting.

The method of joining resin pipes according to the present invention is not limited to the above embodiment. For example, in the above embodiment, the heating elements 3 and 4 are separate bodies, but a heating element in which the convex portion and the concave portion are integrated so that their backs face each other may be used.

[0019]

EFFECT OF THE INVENTION Since the resin pipe joining method according to the present invention is configured as described above, the occurrence of stress due to the diameter expansion in the joint at the time of joining is reduced, and the hydraulic strength of the joint can be improved by the synthetic resin pipe or It can be more than a fitting. In addition, since it is not necessary to scrape the melted portion of the receiving end of the joint at the end of the synthetic resin pipe at the time of joining, it is possible to prevent the formation of beads that are the source of generation of viable bacteria.

In particular, according to the second aspect, it is possible to use the conventional synthetic resin pipe as it is without the trouble of cutting the pipe end portion, and the workability is good and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the joining method of claim 1 in the order of steps.

FIG. 2 shows an embodiment of the joining method according to claim 1,
It is sectional drawing showing the state at the time of the completion of joining.

FIG. 3 is a cross-sectional view showing an embodiment of the joining method of claim 2 in the order of steps.

FIG. 4 is a sectional view illustrating a conventional joining method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin pipe 12 Receptacle fitting part 2 Joint 21 Receptacle 3 Heating body 4 Heating body

Claims (2)

[Claims] Claim: What is claimed is: 1. An inner peripheral surface of a receiving port of a synthetic resin joint, the diameter of which is tapered toward the inner side, and an outer peripheral surface of a receiving port fitting portion of a synthetic resin pipe are melted by heating, While maintaining this heating and melting state, a synthetic resin for fitting the receiving port fitting portion of the synthetic resin pipe into the receiving port of the joint, cooling and solidifying the molten portion to integrate the synthetic resin pipe into the joint. In the method of joining pipes, prior to heating and melting, the outer peripheral surface of the receiving port fitting portion of the synthetic resin pipe is cut so as to reduce the diameter at the same or a smaller diameter reducing angle than the inner peripheral surface of the receiving port. A method for joining synthetic resin pipes characterized by processing. 2. An inner peripheral surface of a receiving opening of a synthetic resin joint, which is tapered toward the inner side, and an outer peripheral surface of a receiving fitting portion of a synthetic resin pipe are melted by heating, While maintaining this heating and melting state, a synthetic resin for fitting the receiving port fitting portion of the synthetic resin pipe into the receiving port of the joint, cooling and solidifying the molten portion to integrate the synthetic resin pipe into the joint. In the method for joining pipes, the inlet fitting portion of the synthetic resin pipe is fitted to a tubular heating element whose diameter is reduced at the same or smaller diameter as the inner peripheral surface of the inlet. A method for joining synthetic resin pipes, characterized in that the socket fitting portion is heated and melted, and at the same time, the heating member is molded into an inner surface shape.