Patent ID: 9004542
Filing Date: 2015-04-14
Classification: F02M,F16L

Abstract:
1. A pipe fastening structure used in high-pressure fuel lines comprising: an end member attached to an end part of a metal pipe; a nut for fastening the end part of the metal pipe; and a counterpart to which the end part of the metal pipe is fastened by the nut; wherein the end member has a first spherical part to be brought into contact with a sealing surface formed in the counterpart, a second spherical part formed integrally with the first spherical part so as to be in contact with a sliding surface formed in the nut, and a neck continuous with the second spherical part and having the shape of the metal pipe, an outside diameter D such that the end member and the nut do not turn together relative to the counterpart when torque is applied to the nut so that damage to the sealing surface and the sliding surface is prevented; and a step portion is formed in an inside portion of the nut near a tail end of the nut where the neck is located, wherein the step portion makes a portion of an inner diameter of the nut smaller, and wherein the step portion is adjacent to the neck.