Patent ID: 7100577

Claim:
A common rail directly actuated fuel injection valve comprises: (a) a valve body that defines a fuel inlet and a fuel cavity in communication with said fuel inlet; (b) a valve member movable within said valve body between a closed position at which said valve member is in sealed contact with a valve seat to hold fuel within said fuel cavity, and at least one open position at which said valve member is spaced apart from said valve seat to allow said fuel to flow from said fuel cavity and out of said fuel injection valve; (c) an actuator comprising a drive member that is controllable to produce a mechanical strain in said drive member; (d) a reservoir disposed within said valve body and filled with a hydraulic fluid, wherein said reservoir is fluidly sealed from said fuel cavity; (e) a hydraulic transmission device associated with said actuator and said valve member, said hydraulic transmission device comprising a transmission cavity filled with said hydraulic fluid for transmitting said mechanical movement from said drive member to said valve member, wherein said transmission cavity is in restricted fluid communication with said reservoir whereby hydraulic fluid can flow between said reservoir and said transmission cavity when said valve member is in said closed position and no substantial hydraulic fluid flows between said reservoir and said transmission cavity when said valve member is in an open position; and (f) a pressure regulating device disposed within said valve body between said fuel cavity and said reservoir, whereby hydraulic fluid within said reservoir is pressurizable by fuel pressure within said fuel cavity.