SOLENOID ACTUATOR AND FUEL INJECTOR USING SAME

摘要

In one aspect, a fuel injector (10) includes an injector body (11) that defines a fuel inlet (12), a drain outlet (13) and a nozzle outlet (14). A direct operated check valve (20) is positioned in the injector body (11) and includes a needle valve member (21) with an opening hydraulic surface (22) exposed to fluid pressure in a nozzle supply passage (16), and a closing hydraulic surface (23) exposed to fluid pressure in a needle control chamber (17). The needle valve member (21) is movable between a first position at which the nozzle supply passage (16) is blocked to the nozzle outlet (14), and a second position at which the nozzle supply passage (16) is open to the nozzle outlet (14). A needle control valve (30) is positioned in the injector body (11) and includes a control valve member (31) movable between a first position at which the needle control chamber (17) is fluidly connected to the drain outlet (13), and a second position at which the needle control chamber (17) is fluidly blocked to the drain outlet (13). A solenoid actuator (50) is positioned in the injector body (11) and includes a stator assembly (51) and an armature assembly (52, 152) coupled to the control valve member (31). One of the stator assembly (51) and the armature assembly (52, 152) includes a non-magnetic insert (55, 155, 255) that moves into and out of contact with another of the stator assembly (51) and the armature assembly (52, 152) at an energized position and a de-energized position, respectively.