Fuel injector assembly and internal combustion engine including same

摘要

A fuel injector assembly is provided which includes a control valve actuated by a piezoelectric actuator acting through a hydraulic amplifier to facilitate pressurization of fluid fuel within the fuel injector assembly for dispersing the fuel into a combustion chamber. The piezoelectric actuator is excited by a variable voltage source to control the degree of displacement of the hydraulic amplifier to control the degree of fluid fuel dispersement by controlling the degree of displacement of the control valve. The configuration of the control valve may be such as to provide multi-step fluid fuel dispersing thereby providing a low fuel injection pressure and rate followed by a higher fuel injection pressure and rate. Multi-step fluid fuel dispersing may also be accomplished by varying the level of excitation voltage to the piezoelectric actuator. A pressure check valve is provided to prime the hydraulic amplifier cavity, to expel trapped air therefrom, to compensate for fuel leakages from the cavity and to circulate fuel through the cavity. An internal combustion engine including such a fuel injector assembly is also provided.