COMMON RAIL AND METHOD OF MANUFACTURING THE SAME

摘要

There is provided a common rail which can effectively restrict a generation of a tensile stress in a lower end inner peripheral edge portion of a branch hole by canceling by means of a compression residual stress 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 is only added to a normal manufacturing process, no complex equipment is required, and 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 a method of manufacturing a common rail structured such that a branch hole communicating with an communication passage of a block rail and having a pressure receiving seat surface open to an outer portion is provided in at least one connecting hole portion provided in a peripheral wall portion in an axial direction of the block rail having the communication passage in a longitudinal inner portion, a pressing seat surface constituted by a connecting head portion provided in an end portion of a branch having a flow passage communicating with the communication passage is brought into contact with and engaged with the pressure receiving seat surface, and the connecting hole portion and a fastening nut previously assembled in the branch pipe are meshed with each other so as to fasten and connect together with pressing under a neck of the connecting head portion, a pressing force is applied to an axial direction of the connecting hole portion from an outer portion by a press method so as to generate a compression residual stress in the periphery of an open end portion of the communication passage of the block rail of the branch hole.