PIPE JOINT STRUCTURE

PROBLEM TO BE SOLVED: To provide a pipe joint structure capable of improving coming-off prevention effect of a reinforcing cylindrical body mounted in an insertion pipe part while facilitating mounting work of the reinforcing cylindrical body by simple and inexpensive remodeling for each locking piece. SOLUTION: The reinforcing cylindrical body 7 is internally fitted into a region from a tip in the insertion pipe part 2 to a section equivalent to a section where biting action of a locking member 4 is applied, and an outside diameter of an internally fitted cylindrical part 7A of the reinforcing cylindrical body 7 fitted internally into the insertion pipe part 2 is set to be smaller than an inside diameter of the insertion pipe part 2. Locking pieces 7a, 7b which are positioned by protruding outward in the radial direction more than an inner peripheral face of the insertion pipe part 2 and are elastically deformed inward in the radial direction in accordance with the insertion into the insertion pipe part 2 are formed in a plurality of sections in the peripheral direction of the reinforcing cylindrical body 7 and in a section corresponding to a tip part side of the insertion pipe part 2 when it is internally fitted. Furthermore, contact positions of the locking pieces 7a, 7b for the insertion pipe part 2 differ in two senctions or more in at least the direction of pipe shaft axis.