| 摘要 |
PROBLEM TO BE SOLVED: To provide a common rail which can improve inner pressure fatigue strength at a connection part to a branch pipe, improve durability, and eliminate fluid leakage due to generation of cracking and manufacture of the common rail of high quality only by adding a pressurizing force applying process such as pressing to a normal manufacturing process. SOLUTION: At least one branch hole 1-2 is formed on an axially peripheral wall of a main pipe rail 1. In addition, a receiving seat surface 1-3 is formed, abutted against and engaged with a pressing seat surface 2-3. Fastening and connection are performed by screwing an independent joint fitting 3 surrounding an outer peripheral part of the main pipe rail with a nut 4 previously assembled in a branch pipe 2, accompanied with pressing force below the connection head 2-2. Pressing force is applied to the main pipe rail 1 near the branch hole in a diameter direction by pressing from the outside. Thus compression residual stress is generated around an opening end of the branch hole 1-1 to the main pipe rail. |
