Electromagnetic fuel injection valve and process for producing the same

An electromagnetic fuel injection valve comprising:

• a valve member contained in a valve housing comprising a magnetic cylinder coaxially coupled at a front end thereof to a valve seat member having a valve seat, said valve member being spring-biased in a direction in which said valve member is seated on said valve seat, wherein an outer diameter of said magnetic cylinder and an outer diameter of said valve seat member are equal to each other;
• a non-magnetic cylinder serving as a member different from said magnetic cylinder is coaxially coupled at a front end thereof to a rear end of the magnetic cylinder to surround a portion of a movable core which is coaxially connected to said valve member with a rear end face thereof serving as a movable attraction face;
• a stationary core having a front portion that includes a front end face serving as a stationary attraction face is fitted into and fixed in a rear portion of said non-magnetic cylinder, so that said stationary attraction face is opposed to said movable attraction face,
• wherein the front portion of said stationary core is fitted and fixed in said non-magnetic cylinder to be in close contact with an inner surface of an intermediate portion of said non-magnetic cylinder in a region corresponding to said stationary attraction face;
• an annular recess having a flat portion in communication with said stationary attraction face;
• an annular chamber;
• a center bore having an inside diameter larger than an outside diameter of said stationary attraction face is defined by the inner peripheral surface of said non-magnetic cylinder and in communication with said annular recess;
• and
• a guide bore defined by an inner periphery of said magnetic cylinder and in communication with said center bore,
• wherein said annular chamber is defined by said flat portion of said annular recess being connected to said center bore and guide bore by an inclined surface and by an area between said annular recess, an outer periphery of said movable core, and an inner peripheral surface of said non-magnetic cylinder.