Ring joint, connection structure for connecting piping and ring joint, and method of connecting ring joint and piping

摘要

This invention provides a connection structure for connecting a piping used in automobiles or the like to a ring joint for providing highly reliable gas-tightness. The connection can be performed with an easy and inexpensive method and also can provide excellent productivity and safety. The connection structure has highly reliable disengagement resistance. The ring joint has a: a ring joint body including: a fitting hole for an eyebolt, the fitting hole being piercingly formed in an axial core portion of the ring joint body and in continuation from an annular recessed groove formed inside the ring joint body, and a flow path extending in a direction perpendicularly intersecting with the fitting hole; and a branch pipe formed as a united body with the ring joint body and disposed in a direction perpendicularly intersecting with the eyebolt. A piping for insertion into the branch pipe has an outer peripheral surface covered with resin, in which the resin of the outer peripheral surface of the piping and an inner peripheral surface of the branch pipe are fixedly welded by a welding means.