High pressure piezoelectric fuel injector

A high pressure fuel injector for direct injection of fuel into a cylinder of a compression ignition engine, said fuel injector comprising:

• a housing;
• a piston movable within a bore within said housing;
• a piezoelectric actuator disposed within said housing, said piezoelectric actuator having a first end seated against said housing and a second end operatively coupled to said piston;
• said housing comprising a cylinder head, said cylinder head and said piston forming a pressurization chamber therebetween;
• a needle valve assembly comprising a needle component movable within a bore within said piston, said needle component spring loaded against said piston and seated within a needle valve seat;
• said needle valve seat disposed on said cylinder head across said pressurization chamber from said piston;
• said housing having a fuel input port formed in said housing, said fuel input port configured for coupling said fuel at an input pressure at said input port through an input check valve to said pressurization chamber;
• said pressurization chamber coupled to an injection nozzle through said needle valve assembly;
• wherein during operation, the piezoelectric actuator drives the piston a displacement distance toward the cylinder head in response to an electrical input, generating a high pressure in the pressurization chamber, said high pressure higher than said input pressure;
• said high pressure coupled to said spring loaded needle component and said high pressure lifts said spring loaded needle component to open said needle valve assembly and allow a portion of high pressure fuel from said pressurization chamber to exit between the spring loaded needle component and the needle valve seat, delivering said portion of said high pressure fuel from said pressurization chamber through said needle valve assembly and said injection nozzle to said cylinder of said engine.