Abstract: An inner tubular portion (15) and an outer tubular portion (16) form an insertion space (14) of a plastic pipe (11) and are integrally formed on a joint main body (13). A cap (29) is connected to the outer tubular portion (16) by projection-recess engagement. A retainer mechanism (27) of the plastic pipe (11) is provided between the outer tubular portion (16) and the cap (29). A cutout portion (20) is formed in the outer tubular portion (16), and a bulging engagement portion (24) is arranged on the cutout portion (20). The outer periphery of the bulging engagement portion (24) is connected to the cap (29) by the projection-recess engagement. A restricting portion is provided between the cutout portion (20) and the bulging engagement portion (24). The restricting portion is composed of a first tapered surface (21) and a second tapered surface (25). The first tapered surface (21) is provided on the cutout portion (20) and decreases in width toward the outer end.

Abstract: An inner tubular portion (15) and an outer tubular portion (16) form an insertion space (14) of a plastic pipe (11) and are integrally formed on a joint main body (13). A cap (29) is connected to the outer tubular portion (16) by projection-recess engagement. A retainer mechanism (27) of the plastic pipe (11) is provided between the outer tubular portion (16) and the cap (29). A cutout portion (20) is formed in the outer tubular portion (16), and a bulging engagement portion (24) is arranged on the cutout portion (20). The outer periphery of the bulging engagement portion (24) is connected to the cap (29) by the projection-recess engagement. A restricting portion is provided between the cutout portion (20) and the bulging engagement portion (24). The restricting portion is composed of a first tapered surface (21) and a second tapered surface (25). The first tapered surface (21) is provided on the cutout portion (20) and decreases in width toward the outer end.