Patent ID: 8201543
Filing Date: 2012-06-19
Classification: F02M

Abstract:
1. A piezoelectric-actuated fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, comprising: an injector body containing an injector cavity and an injector orifice communicating with one end of said injector cavity to discharge fuel into the combustion chamber; a needle valve positioned in one end of said injector cavity adjacent said injector orifice, said needle valve movable between an open position in which fuel flows from the fuel supply circuit through said injector orifice into the combustion chamber and a closed position in which fuel flow through said injector orifice is blocked; a piezoelectric actuator including a stack of piezoelectric elements movable to expand in a first direction and movable to contract in a second direction opposite said first direction; a hydraulic link assembly disposed within said injector cavity, said hydraulic link assembly including a hydraulic link barrel having an inner bore, a hydraulic link outer plunger positioned to slidably move in said inner bore and operably connected to said piezoelectric actuator, and a hydraulic link positioned between said hydraulic link barrel and said hydraulic link outer plunger, said hydraulic link operatively connected to said needle valve to move said needle valve in said second direction toward said open position in response to movement of said stack of piezoelectric elements in said first direction.