| 摘要 |
PROBLEM TO BE SOLVED: To improve fatigue strength to internal pressure in a part around an opening of a branching hole in an inner wall of a rail hole. SOLUTION: In assembly, a ring member 20 is externally fitted to a corresponding position to the branching hole 13 in an outer periphery of a cylindrical member 10, and compressive residual stress is given to the part 15 around the opening of the branching hole 13 in the inner wall of the rail hole 11 by fastening force in the direction to relatively reduce a diameter from the ring member 20 to the cylindrical member 10. Since the compressive residual stress is given at the part 15 around the opening of the branching hole 13 in the inner wall of the rail hole 11, tensile stress caused by the internal pressure of pressurized fuel is suppressed and the fatigue strength to the internal pressure is improved. |
