Patent ID: 6026785
Filing Date: 2000-02-22
Classification: F02M

Abstract:
A hydraulically actuated fuel injector comprising:an injector body defining an actuation fluid inlet, a first actuation fluid passage, a second actuation fluid passage, a fuel inlet and a nozzle outlet;a solenoid actuated control valve including a spool valve member positioned in said injector body and being movable between a first position and a second position;said actuation fluid inlet being closed to said first actuation fluid passage and open to said second actuation fluid passage when said spool valve member is in said first position, and said actuation fluid inlet being open to said first actuation fluid passage and closed to said second actuation fluid passage when said spool valve member is in said second position;a piston positioned in said injector body and being movable between a retracted position and an advanced position, and said piston having an upper end exposed to fluid pressure in said first actuation fluid passage; anda needle valve member positioned in said injector body and being movable between an inject position in which said nozzle outlet is open, and a closed position in which said nozzle outlet is blocked, and said needle valve member having a closing hydraulic surface exposed to fluid pressure in said second actuation fluid passage.