Compressed natural gas injector with gaseous damping for armature needle

Abstract

An electromagnetically operable fuel injector, for a gaseous fuel injection system of an internal combustion engine is disclosed, the injector having a generally longitudinal axis, 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 of a fuel valve and is movable away from the fixed valve seat when the magnetic coil is excited, the armature having a generally elongated shape and a generally central opening for axial reception and passage of gaseous fuel from a fuel inlet connector positioned adjacent thereto. The fuel inlet connector and the armature are adapted to permit a first flow path of gaseous fuel through a working gap between the fuel inlet connector and the armature and between the armature and the magnetic coil as part of a path leading to the fuel valve. The combined flow area across the working gap between the armature and the magnetic coil and valve body shell exceeds the area available for fuel flow through the armature. A method of directing gaseous fuel through the fuel injector is also disclosed.