The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 2002
Filed:
Mar. 20, 1998
Kikuo Asada, Mishima, JP;
Masayoshi Usui, Numazu, JP;
Eiji Watanabe, Tagata-gun, JP;
Kazunori Takikawa, Numazu, JP;
Ryuichi Kusanagi, Numazu, JP;
Abstract
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.