| 摘要 |
There is provided a common rail which can effectively restrict a generation of a stress in a lower end inner peripheral edge portion of a branch hole and can improve an internal pressure fatigue strength in a branch pipe connecting portion, so that a secure and stable function can be obtained by having an excellent durability and preventing a fluid leakage due to a generation of the crack generation and a method of manufacturing a common rail in which a pressure application process by the press is only added to a normal manufacturing process, no complex equipment is required, a common rail having a high quality can be manufactured by a low cost without generating problems that an equipment cost is increased by an increase of the process and a productivity is reduced. In the method of the invention, there is provided a method of manufacturing a common rail comprising at least one branch hole provided in an axial peripheral wall portion of a main pipe rail having a communication passage inside an axial core, a pressure receiving seat surface communicating with a branch pipe having a communication passage communicating with the communication passage in a peripheral surface portion of the branch hole and open to an outer portion, thereby bringing a pressing seat surface portion constituted by a connection head portion disposed in an end portion of the branch pipe into contact and engaging therewith, and a joint metal fitting surrounding an outer peripheral portion of the main pipe rail and a nut previously assembled in the branch pipe end which are meshed with each other so as to be pressed under a neck portion of the connection head portion, thereby being fastened and connected, wherein a pressing force is applied to the main pipe rail near the branch hole from an outer portion to a diametrical direction by a press method, thereby generating a compression residual stress at a portion near the open end portion of the communication passage of the main pipe rail in the branch hole. |
