Patent ID: 7090145

Claim:
A fuel injection valve comprising: (a) an injection valve body that comprises a longitudinal axis with an injector tip comprising at least one nozzle orifice associated with one end of said longitudinal axis, wherein said injector tip is installable at a location in an engine where a liquid fuel can be injected directly into a combustion chamber through said at least one nozzle orifice; (b) a fuel cavity disposed within said injection valve body near said injector tip; (c) a valve member disposed within said injection valve body, wherein said valve member is movable parallel to said longitudinal axis between a closed position where said valve member contacts a valve seat, and an open position where said valve member is spaced apart from said valve seat, whereby said liquid fuel may flow from said fuel cavity, between said valve member and said valve seat, and into said combustion chamber through said at least one nozzle orifice; (d) a fuel supply passage disposed within said injection valve body and communicating between a fuel inlet port and said fuel cavity; (e) a drain passage communicating between said fuel cavity and a drain system for returning said liquid fuel to a fuel supply system; and (f) a drain valve associated with said drain passage and disposed within said injection valve body, wherein said drain valve is closeable to stop fuel from flowing through said drain passage, wherein said drain valve is operable independently from actuation of said valve member, and wherein said drain valve is spring biased so that it does not open unless fuel pressure within said fuel cavity is greater than a predetermined set point.