Low Leakage Cam Assisted Common Rail Fuel System, Fuel Injector, And Operating Method Therefor

摘要

A fuel system includes a plurality of fuel injectors each defining a nozzle supply passage, a nozzle outlet and a low pressure space. The fuel system includes a plurality of mechanically actuated pressure intensifiers each including a tappet and being positioned partially within one of the fuel injectors, and a common rail fluidly connecting with each of the fuel injectors. Each of the fuel injectors further includes an injection pressure control mechanism having an injection pressure control valve. Each injection pressure control valve blocks the corresponding pressure intensifier from the common rail and fluidly connects the pressure intensifier with the low pressure space at a first position, and fluidly connects the pressure intensifier with the common rail and blocks the pressure intensifier from the low pressure space at a second position. Injecting fuel via operating the fuel system may include operating the fuel system in a low leakage mode where the pressure intensifier displaces fuel at a low pressure, between high pressure injections.