Compressed natural gas injector having gaseous dampening for armature needle assembly during closing

• Main Authors: Fochtman, James P, Wright, Danny O, Cohen, James H
• Format: Patent
• Language: English
• Published: 23.07.2002

1. Field of the Invention An electromagnetically operable fuel injector for a gaseous fuel injection system of an internal combustion engine, the injector having a generally longitudinal axis, which includes 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 in the form of a valve needle 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 fixed valve seat defines an aperture of predetermined dimension for passage of fuel therethrough, 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 between the armature and the magnetic coil as part of a path leading to said fuel valve. An orifice device is positioned downstream of the fuel valve and defines an orifice for reception of fuel from the fuel valve, the orifice being of lesser dimension than the aperture of said fixed valve seat. A method of directing gaseous fuel through an electromagnetically openable fuel injector in a manner which provides dampening of the valve needle upon closing is also disclosed.