Manufacturing method of the joint structure and branch branch pipe and its branches line of the branch branch pipe in the internal combustion engine for fuel rail

摘要

PPROBLEM TO BE SOLVED: To provide a joint structure of a diverging branch pipe in a fuel rail for an internal combustion engine preventing corrosion of component parts such as the fuel rail and the diverging branch pipe and preventing oxidation and deterioration of fuel. PSOLUTION: The joint structure of the diverging branch pipe in the fuel rail for the internal combustion engine connects the fuel rail for the internal combustion engine, which is made of stainless steel or made of steel with a rustproof treatment on at least an inner surface, and the diverging branch pipe, which comprises a double pipe composed of an outer pipe and an inner pipe with its inner peripheral surface more excellent in rustproof ability with respect to the fuel than an outer peripheral surface of the outer pipe, by a fastening nut through a joint fitting. A connection seal portion of the diverging branch pipe and the joint fitting has rustproof ability equal to the inner peripheral surface of the diverging branch pipe and an entire liquid contact portion including a seal surface of the diverging branch pipe with respect to the fuel pipe is covered with the inner pipe. PCOPYRIGHT: (C)2006,JPO&NCIPI