Piezo Actuator

The piezo actuator consists of a series of small disks. When the piezo actuator is electrically energized, it causes the disks to deform which results in an expansion. The expansion generates a longitudinal motion which pushes down against the valve piston. The piezo actuator returns to its non-energized state by fuel and spring pressure during engine operation, and by the spring pressure from the fuel injector valve return spring when the engine is shut down.