PIEZOELECTRIC DIRECT ACTING FUEL INJECTOR WITH HYDRAULIC LINK

摘要

A piezoelectric-actuated fuel injector for injecting fuel into a combustion chamber of an internal combustion engine is provided which includes a piezoelectric actuator movable to expand in a first direction and movable to contract in a second direction opposite the first direction, and a hydraulic link assembly disposed within said injector cavity. The hydraulic link assembly includes a hydraulic link barrel having an inner bore, a hydraulic link outer plunger positioned to slidably move in the inner bore, and a hydraulic link operatively connected to a needle valve to move the needle valve in the second direction toward the open position in response to movement of the piezoelectric actuator in the first direction. A hydraulic link inner plunger is attached to the needle valve and extends into a center bore of the hydraulic link outer plunger. Leakage control features and hydraulic link refill valves are also provided.