Pipe joint

A pipe joint comprising:

• an inner ring having a bulge portion formed on a first axial side so as to project radially outward, the bulge portion being for press-fitting into an end portion of a tube;
• a joint body having an inner circumference into which an end on a second axial side of the inner ring is to be press-fitted in a state where the bulge portion is press-fitted into the end portion of the tube, the joint body having an external thread on an outer circumference thereof;
• and
• a union nut having an internal thread to be tightened to the external thread, and configured to press the end portion of the tube toward the second axial side when the internal thread is tightened to the external thread, wherein
• the bulge portion has:
• a maximum thickness portion in which a thickness in a radial direction thereof is maximum;
• and
• a tapered portion formed so as to be tapered from the maximum thickness portion toward the first axial side of the inner ring and configured to generate a surface pressure between the tube and the tapered portion by pressing by the union nut,
• in an axial cross-sectional view, an outer circumferential surface of the tapered portion has:
• a concave surface portion formed in a concave surface shape;
• and
• a convex surface portion formed in a convex surface shape on the first axial side with respect to the concave surface portion in the axial cross-sectional view,
• the convex surface portion is formed at an end portion of the tapered portion toward the first axial side of the inner ring, and
• the concave surface portion is gradually recessed radially inward from an axial end of the maximum thickness portion to an axial end of the convex surface portion.