Enhanced needle motion controller

摘要

A controller for controlling a needle valve of a spring closing type fuel injector includes a fluid assist selectively exerting a force on the needle valve, the force acting in cooperation with a bias exerted by a return spring on the needle valve to effect a relatively low valve opening pressure of the needle valve and relatively very high valve closing pressure. A spring closing type fuel injector and a method for controlling a needle valve of a spring closing type fuel injector are further included.