Pipe joint

Abstract

A pipe joint includes a joint body formed with a through hole therein along an axial direction, and having male threads and an extending shaft portion formed on one end side thereof; and a nut member formed with an insertion hole through which a tube member is inserted, and having female threads formed therein that screw-engage with the male threads. Annular projections are formed on an outer circumferential surface of the extending shaft portion, and the tube member, which is expanded in diameter, is gripped between the annular projections and an inner circumferential surface of the nut member.

What is claimed is: 
     
         1 . A pipe joint comprising:
 a joint body formed with a through hole therein along an axial direction, and having male threads and an extending shaft portion formed on one end side thereof; and   a nut member formed with an insertion hole through which a tube member is inserted, and having female threads formed therein that screw-engage with the male threads, wherein:   annular projections are formed on an outer circumferential surface of the extending shaft portion; and   the tube member, which is expanded in diameter, is gripped between the annular projections and an inner circumferential surface of the nut member.   
     
     
         2 . The pipe joint according to  claim 1 , wherein:
 a first tapered surface is formed on an end of the extending shaft portion;   an annular latching part is formed on an edge of an opening of the insertion hole proximate the first tapered surface;   an inner wall surface of the expanded diameter tube member is pressed against the first tapered surface; and   the annular latching part abuts against an outer wall surface of the expanded diameter tube member.   
     
     
         3 . The pipe joint according to  claim 1 , wherein:
 a second tapered surface, which flares outward in a direction toward the male threads, is formed on an end of the extending shaft portion on a side proximate the male threads;   a third tapered surface is formed on an inner circumferential surface of the nut member at a position facing the second tapered surface; and   the expanded diameter tube member is sandwiched between the second tapered surface and the third tapered surface.   
     
     
         4 . The pipe joint according to  claim 1 , wherein projections, which regulate an amount of tightening of the nut member with respect to the joint body, are formed on an end surface of the nut member. 
     
     
         5 . The pipe joint according to  claim 4 , wherein:
 plural arcuately shaped grooves are formed on the joint body in confronting relation to the projections;   the plural arcuately shaped grooves have widths that allow insertion of the projections therein; and   the projections and the plural arcuately shaped grooves are disposed on a common circumference as viewed in the axial direction.   
     
     
         6 . The pipe joint according to  claim 1 , wherein:
 nut side annular projections are formed on the inner circumferential surface of the nut member; and   the nut side annular projections press against the expanded diameter tube member in directions toward recesses that are formed between adjacent ones of the annular projections.   
     
     
         7 . The pipe joint according to  claim 1 , wherein:
 nut side annular projections are formed on the inner circumferential surface of the nut member; and   the nut side annular projections press against the expanded diameter tube member in directions toward the annular projections.