Method for joining pipes and junction structure for joining pipes

Abstract

The present invention is a method for joining pipes in which a first pipe in which at least one portion to be engaged that is sunk inward to an inner circumferential surface side is provided in an outer circumferential surface of an end portion of the first pipe, and a second pipe that is made of thermoplastic resin are joined together, and includes: a first step in which an end portion of the first pipe is inserted into an end portion of the second pipe; and a second step in which, as a result of a transmitting component that transmits ultrasonic waves being pressed against a position on an outer circumferential surface side of the second pipe that corresponds to the portion to be engaged of the inserted first pipe, the second pipe is softened by the ultrasonic waves so that an engaging portion is formed which is made to protrude into the portion to be engaged, which is positioned on the inner circumferential surface side of the first pipe, and becomes engaged with this portion to be engaged.

1 . A method for joining pipes in which a first pipe in which at least one portion to be engaged that is sunk inward to an inner circumferential surface side is provided in an outer circumferential surface of an end portion of the first pipe, and a second pipe that is made of thermoplastic resin are joined together, comprising:
 a first step in which an end portion of the first pipe is inserted into an end portion of the second pipe; and   a second step in which, as a result of a transmitting component that transmits ultrasonic waves being pressed against a position on an outer circumferential surface side of the second pipe that corresponds to the portion to be engaged of the inserted first pipe, the second pipe is softened by the ultrasonic waves so that an engaging portion is formed which is made to protrude into the portion to be engaged, which is positioned on the inner circumferential surface side of the first pipe, and becomes engaged with this portion to be engaged.   
     
     
         2 . The method for joining pipes according to  claim 1 , wherein
 the second pipe is provided with at least one protruding portion on an outer circumferential surface of an end portion thereof that corresponds to the portion to be engaged of the first pipe, and,   in the second step, the engaging portion is formed by this protruding portion being pressed by the transmitting component.   
     
     
         3 . The method for joining pipes according to  claim 1 , wherein
 the portion to be engaged of the first pipe is a through hole that penetrates from the outer circumferential surface to the inner circumferential surface of the first pipe, and,   in the second step, after a molding jig has been positioned inside the first pipe within a range where at least the through hole is formed and while being positioned apart from the inner circumferential surface of the first pipe, the transmitting component is pressed against the second pipe so that a portion of the second pipe is made to protrude onto the inner circumferential surface side of the first pipe as an engaging portion until the second pipe is deformed by the molding jig.   
     
     
         4 . A junction structure for joining pipes together in which an end portion of a first pipe is inserted into an end portion of a second pipe that is made from a thermoplastic resin, comprising:
 at least one portion to be engaged that is provided on an outer circumferential surface of an end portion of the first pipe so as to be sunk inward to the inner circumferential surface side; and   an engaging portion that is provided so as to protrude from the inner circumferential surface of the end portion of the second pipe   wherein the engaging portion is engaged the portion to be engaged.   
     
     
         5 . The junction structure for joining pipes according to  claim 4 , wherein
 the engaging portion is formed as a result of the second pipe being softened and deformed by ultrasonic waves.   
     
     
         6 . The junction structure for joining pipes according to  claim 5 , wherein
 the engaging portion is a portion which is made to protrude onto the inner circumferential surface side as a result of ultrasonic waves being transmitted to the protruding portion which is protruding on the outer circumferential surface side of the second pipe.   
     
     
         7 . The junction structure for joining pipes according to  claim 4 , wherein
 the portion to be engaged is a through hole that penetrates from the outer circumferential surface side to the inner circumferential surface side of the first pipe, and   a distal end of the engaging portion protrudes onto the inner circumferential surface side of the first pipe, and the width of the distal end is wider than the width of the through hole.