Patent ID: 7628344
Filing Date: 2009-12-08
Classification: F02M

Abstract:
1. A fuel injector assembly comprising: a nozzle body including a chamber therein and an opening in fluid communication with the chamber; a fuel channel in fluid communication with the chamber; a valve needle positioned in the chamber and being operable to open and close the opening; and a dead spring including a first end and a second end, said dead spring having at least two of its coils being at all times at least partially in continuous, intimate contact with each other in its natural state, said dead spring being positioned in the chamber and being in contact with the valve needle, said dead spring being operable to provide a force against the valve needle to close the opening an wherein said at least two coils of the dead spring in partial continuous, intimate contact are at all times at least partially in continuous, intimate contact with each other during compression and expansion of said dead spring; wherein fuel is supplied at a select valve opening pressure (VOP) against the force of the dead spring to open the valve needle, and wherein the dead spring is sized and shaped to reduce wear of the dead spring over time thereby lowering the valve opening pressure and limiting blow back into the fuel channel in order to reduce NOx emissions.