RATE SHAPED FUEL INJECTOR WITH INTERNAL DUAL FLOW RATE ORIFICE

摘要

A fuel injector nozzle assembly (10) includes a nozzle body (11) that defines a nozzle outlet (18). A needle valve member (30) is positioned in the nozzle body (11) and moveable between a first position in which the nozzle outlet (18) is blocked and a second position in which the nozzle outlet (18) is open. At least one of the nozzle body (11) and the needle valve member (30) define a first chamber (23) fluidly connected to a second chamber (24) by at least one dual flow rate orifice (35). The needle valve member (30) displaces fluid from the first chamber (23) into the second chamber (24) through the at least one dual flow rate orifice (35) when moving from its first position to its second position. The dual flow rate orifice (35) is sized and shaped to produce a flow restriction and to slow the movement of the needle valve member (30) when moving from its closed position to its open position, but permit relatively unrestricted displacement flow in the opposite direction.