TURBOCHARGER HAVING PNEUMATIC ACTUATOR WITH PILOT VALVE

摘要

A pneumatic actuator for controlling the wastegate valve of an exhaust gas driven turbocharger includes a pilot piston (78) which is responsive to boost pressure to open only when a desired boost pressure is attained. Accordingly, premature opening of the wastegate valve is avoided because the main actuator piston (66) is maintained at atmospheric pressure until the desired actuating pressure is attained.