Patent ID: 7896257

Claim:
A fuel injection apparatus, comprising: an injector body casting containing a fuel passage communicating to high pressure fuel supply and a pressure cavity for storing fuel supplied from said fuel passage; at least one orifice for discharging fuel; at least one piston device including a channel and a piston disposed in said channel, one end of said piston communicating to high pressure fuel supply, and the other one communicating to said pressure cavity; a nozzle valve element slidably disposed adjacent said injector orifices, controlling fuel flow by moving from an open position at which fuel in said pressure cavity may flow through said injector orifices, and a closed position at which fuel flow is blocked by said nozzle valve element, said nozzle valve element controls fuel flow to said pressure cavity by fluidly connecting said pressure cavity to the fuel passage in said injector body when the fuel injection apparatus is de-energized, and fluidly blocking said pressure cavity from the fuel passage in said injector body when the fuel injection apparatus is fully energized.