Abstract: A pipe joint includes: an inner ring having a bulge portion to be press-fitted into an end portion of the tube; a joint body having an inner circumference into which an end portion of the inner ring is to be press-fitted, and having an external thread portion on an outer circumference thereof; and a union nut having an internal thread portion to be tightened to the external thread portion, and configured to press the end portion of the tube when the internal thread portion is tightened to the external thread portion. The bulge portion has a tapered portion configured to generate a surface pressure between the tube and the tapered portion by pressing by the union nut. An outer circumferential surface of the tapered portion has a concave surface portion formed in a concave surface shape in an axial cross-sectional view.

Abstract: A tapered surface 14 is formed at each axially outer end portion of an inner circumferential surface 3a of a gasket 3 such that a diameter thereof gradually increases from an axially inner side toward an axially outer end thereof in a state before an annular primary sealing portion 11 of the gasket 3 is press-fitted into an annular primary sealing groove 2b of a fluid device 2. A diameter increase starting point P1 of the tapered surface 14 is located in a range R from a deformation starting point position P2 serving as a starting point from which the inner circumferential surface 3a is deformed due to the primary sealing portion 11 receiving external force form the fluid device 2 when the primary sealing portion 11 is press-fitted into the primary sealing groove 2b, to a center position P3 in an axial direction of the inner circumferential surface 3a.

Abstract: An inner ring 4 of a pipe joint 1 includes a bulge portion 6 formed at an axially outer end portion thereof so as to project toward a radially outer side, and to be press-fitted into an end portion of a tube 8, and has a fluid flow passage 4a formed on a radially inner side of the bulge portion 6. The bulge portion 6 is formed so as to be tapered from an axially inner side toward an axially outer end thereof in an axial cross-sectional view, and has a flat surface 6e formed at the axially outer end thereof and extending in a radial direction.

Abstract: An inner ring of a pipe joint includes a first tapered surface formed at one axial end portion of an inner circumferential surface such that a diameter thereof gradually increases from another axial side toward one axial end thereof in a state before a bulge portion is press-fitted into an end portion of a tube. A diameter increase starting point of the first tapered surface is located in a range from a deformation starting point, which serves as a starting point from which an inner circumferential surface is deformed due to the bulge portion receiving external force from the tube when the bulge portion is press-fitted into the end portion of the tube, to a position, on the inner circumferential surface, corresponding to one axial end of an outer circumferential surface of a body portion.

Abstract: An inner ring 4 of a pipe joint 1 includes a cylindrical body portion 5 having a communication hole 5a for providing communication between flow passage holes 2c and 8a of a joint body 2 and a tube 8, and an annular primary sealing portion 11 projecting from a radially inner side of an axially outer end portion of the body portion 5 toward an axially outer side and to be press-fitted into an annular primary sealing groove 2d formed on the joint body 2. The primary sealing portion 11 is formed so as to be tapered from an axially inner end thereof toward an axially outer end thereof in an axial cross-sectional view, and has a flat surface 11c extending from a radially outer end 11b of the axially outer end thereof toward the radially inner side.