US Patent 7530506 Fuel injection value

A valve element of a fuel injection valve comprises a cylindrical structural base which has an upper end contactable with a lower end of a core tube installed in a cylindrical case and a spherical valve head which is contactable with a valve seat arranged at a lower end of the cylindrical case. The structural base is a sintered magnetic metal member produced through a metal powder injection molding method and has a relative density ranging from approximately 95% to approximately 98%, and the structure base has, at the end thereof that is contactable with the downstream end of the core tube, a notched surface for suppressing an undesirable sticking of the end of the structural base to the downstream end of the core tube.