Patent ID: 7451942
Filing Date: 2008-11-18
Classification: F02M,Y02T

Abstract:
1. A fuel injection assembly for direct fuel injection of low pressure gaseous fuel into a combustion chamber of an internal combustion engine, the assembly comprising: at least one nozzle having at least one nozzle passage formed by an annular nozzle wall, the at least one nozzle having a nozzle inlet and nozzle outlet, the at least one nozzle passage including a converging portion adjacent the nozzle inlet and a diverging portion adjacent the nozzle outlet, the converging and diverging portions being disposed between the nozzle inlet and outlet; a first critical orifice disposed between the converging and diverging portions of the at least one nozzle passage; valve means for controlling the first critical orifice such that at least a portion of the fuel flow passing through the first critical orifice reaches at least sonic velocity as it travels through the diverging portion of the at least one nozzle passage and exits the nozzle outlet; wherein the first critical orifice is an annular gap formed between the valve means and the annular nozzle wall upon activation of the valve means; and wherein a longitudinal axial length of the diverging portion is between about 15 and about 50 times the width of the annular gap that forms the first critical orifice.