| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-pressure fuel injection pipe capable of increasing the strength of a buckling forming part by preventing an annular acute-angle wrinkle or the cracking produced inside of a head part in accompany with the machining of the head part, and to prevent the possibility of the fatigue failure inside of the head part. SOLUTION: The connecting head part having an outer peripheral face to be used as a truncated conical or circular arc seat face to a counterpart seat part, is formed on a connecting end part of a comparatively small thick steel pipe, an outer peripheral face of a neck lower part of the connection head part is covered, a connection washer having a chamfering elevationθat a connection head part side of 20-40 degrees, a chamfering depth 1 of 0.1-0.6 d (d: pipe diameter), and an axial length L of 0.5-1.5 d, is mounted, and the connection washer and the injection pipe are closely abutted on each other.
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