Compressed natural gas fuel injector having magnetic pole face flux director

Abstract

An electromagnetically operable fuel injector for a fuel injection system of an internal combustion engine is disclosed having a ferromagnetic core, a magnetic coil at least partially surrounding the ferromagnetic core and an armature magnetically coupled to the magnetic coil and being movably responsive to the magnetic coil. The armature actuates a valve-closing element, which interacts with a fixed valve seat and is movable away from the fixed valve seat of a fuel valve when the magnetic coil is excited. The armature has a generally elongated shape and a generally central opening for reception of fuel from a fuel inlet connector positioned adjacent thereto. The fuel inlet connector extends in a generally longitudinal direction above the armature and defines a central path for fuel to enter the inlet connector and to be directed toward the armature for further passage toward the fixed valve seat. The fuel inlet connector has a lowermost end portion spaced above the armature to define a working gap through which the armature is movable to open and close the valve. The lowermost end portion of the fuel inlet connector has a transverse cross-sectional dimension corresponding to the transverse dimension of an upper end face of the armature to define a substantially direct magnetic flux path between the armature and the fuel inlet connector.