主权项 |
1. An apparatus, comprising a pressure compensated fuel injector including:
a cap defining a fuel inlet and a fuel outlet; a pressure tube having a first end coupled to the fuel outlet of the cap; a fuel piston cylinder coupled to a second end of the pressure tube, the fuel piston cylinder defining a plurality of recirculation valves between an exterior surface of the fuel piston cylinder and an interior surface of the fuel piston cylinder, the fuel inlet in fluid connection with the plurality of recirculation valves; a fuel piston located within and in reversible sliding operational engagement with the interior of the fuel piston cylinder to intermittently close the plurality of recirculation valves, the fuel piston defining an injector orifice; a solenoid assembly located within and in sliding operational engagement with the pressure tube, the solenoid assembly including
a magnet having a first end and a second end;a cap valve coupled to the first end of the magnet to intermittently close the fuel outlet;a cap valve spring that applies a restorative force to the cap valve along a direction away from the first end of the magnet;an injection valve coupled to the second end of the magnet to intermittently close the injector orifice, the injection valve in sliding operational engagement with the fuel piston; anda solenoid spring that applies a restorative force to the solenoid assembly along a direction away from the cap and intermittently open the fuel outlet, open the plurality of recirculation valves and close the injector orifice, wherein the pressure tube, the fuel piston cylinder, the plurality of recirculation valves, the fuel piston, the injection valve, the cap and the cap valve define a fuel chamber when a force on the fuel piston along a direction toward the cap, in opposition to the restorative force of the cap valve spring and the restorative force of the solenoid spring, rises above a threshold, thereby closing the cap valve and the plurality of recirculation valves, wherein energizing the solenoid when both the fuel outlet and the plurality of recirculation valves are closed 1) opens the injector orifice and then 2) applies an additional force to the fuel piston along the direction toward the cap, in opposition to the restorative force of the cap valve spring and the restorative force of the solenoid spring, thereby moving the fuel piston toward the cap. |