Patent ID: 6564777
Filing Date: 2003-05-20
Classification: F02B,F02D,F02M,Y02T

Abstract:
An injection valve for injecting fuel into a combustion chamber of an internal combustion engine, said injection valve comprising:(a) a valve housing comprising: a fuel inlet port; an interior chamber fluidly connected to said fuel inlet port; a nozzle comprising a valve seat and at least one nozzle orifice providing a fluid passage from said interior chamber to said combustion chamber; (b) an actuator assembly disposed within said valve housing, said actuator assembly comprising a magnetostrictive member actuatable by imposition of a magnetic field to expand in length to provide a valve opening force; (c) a plurality of portions joined together to form a unitary valve needle disposed within said valve housing and extending through said actuator assembly, said unitary valve needle comprising: a shaft portion formed from a non-ferromagnetic material, said shaft portion extending through said magnetostrictive actuator assembly; a valve needle tip having sufficient durability to contact and seal said valve seat over multiple opening and closing cycles; and a member through which said valve opening force is transferred from said tubular actuator assembly to said unitary valve needle, wherein said unitary valve needle is movable between a closed position at which said valve needle tip contacts said valve seat to fluidly seal said interior chamber from said nozzle orifice, and an open position at which said valve needle tip is spaced apart from said valve seat whereby said interior chamber is fluidly connected with said nozzle orifice; and (d) a needle biasing mechanism associated with said valve needle, said needle biasing mechanism applying a closing force to said valve needle for biasing said valve needle in said closed position.