Fuel injection valve

摘要

This invention serves to suppress the deterioration of oil tightness of a valve after welding without any change in the direction of fuel injection even with deformation of a convex portion after welding of an injection opening plate to a valve seat, as well as without any variation in the direction of fuel injection due to welding variation. In this invention, in a fuel injection valve which has a valve body for opening and closing a valve seat, and receives an operation signal from a control unit to operate the valve body so that fuel is injected from a plurality of injection holes formed in an injection hole plate welded through a welded portion to a downstream side of the valve seat while passing through a gap between the valve body and the valve seat, said injection hole plate is formed at its central portion with a convex portion which is substantially axisymmetric with respect to a valve seat axis and which has a circular-arc shaped cross section, and said welded portion is also substantially axisymmetric with respect to said valve seat axis. In addition, inlet portions of said injection holes are disposed in an injection hole arrangement surface diametrically outside of said convex portion and diametrically inside of a valve seat opening inner wall which is a minimum inside diameter of said valve seat, and said injection hole arrangement surface is coplanar with a surface having said welded portion.