Patent ID: 6257203
Filing Date: 2001-07-10
Classification: F02M

Abstract:
A hydraulically-actuated electronically-controlled fuel injector for use with a fuel injection system having an actuating fluid high pressure common rail for conveying an actuating fluid under pressure, the pressure of the actuating fluid in the common rail being selectively variable, the fuel injection system being installed on a diesel engine, the injector having a controller valve for selectively porting the actuating fluid to an injector intensifier assembly for magnifying the pressure of the file to be injected; comprising:a needle valve for controlling the opening and closing of a fuel injection orifice to effect a fuel injection event, the needle valve being shiftable between a closed disposition and an open disposition, a return spring exerting a bias on the needle valve tending to urge the needle valve into the closed disposition, anda variable valve opening pressure assembly being operably couplable to the needle valve and being in fluid communication with the actuating fluid in the common rail for continuously exposing the needle valve to actuating fluid pressure, the actuating fluid exerting a selectively variable bias on the needle valve, the bias exerting a force on the needle valve tending to urge the needle valve into the closed disposition, the selectively variable bias effecting a variable needle valve valve opening pressure.