Patent ID: 6012429
Filing Date: 2000-01-11
Classification: F02M

Abstract:
A Hydraulically actuated fuel injector comprising:an injector body having a nozzle chamber that opens to a nozzle outlet and a plunger bore, and further having an idle stability port that opens to said plunger bore;hydraulic means for pressurizing fuel in said nozzle chamber, which includes a plunger mounted to reciprocate in said plunger bore between a retracted position and an advanced position;a portion of said plunger bore and said plunger defining a fuel pressurization chamber;a needle valve member mounted to reciprocate in said nozzle chamber between an open position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed;said plunger moving from said retracted position toward said advanced position a relatively short distance when said injector is operating at an idle condition;said idle stability port having a port flow area sufficiently restrictive that pressure in said nozzle chamber is sustained above a valve closing pressure when said idle stability port is open and said injector is operating at said idle condition; anda portion of said plunger blocking said idle stability port when said plunger is in said retracted position.