| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a fuel injection valve solving the problem in a conventional manufacturing method of a fuel injection valve that the roundness of a seat portion becomes worse. SOLUTION: This invention is related to the manufacturing method of the fuel injection valve having a housing 2 internally provided with a valve element, a valve body 6 provided with a seat portion 60 inserted and welded at the lower end of the housing and on which the valve element is seated, and a nozzle hole plate 7 provided with a side wall portion welded at the lower end of the valve body and upwardly raised from the bottom plate portion and the outer periphery of the bottom plate portion. The manufacturing method of the fuel injection valve comprises a nozzle hole plate welding step wherein a valve body lower end is inserted in the inner peripheral side of the side wall portion of the nozzle hole plate having a inner diameter larger than the outer diameter of the valve body lower end and a nozzle hole plate bottom surface and a valve body lower end surface are welded with each other, and a valve body welding step wherein the upper end of the valve body welded with the nozzle hole plate is pressed in the inner peripheral side lower end of the housing and the outer peripheral surface of the pressed-in portion of the valve body and the inner peripheral surface of the housing are welded with each other. |
