Exhaust gas recirculation system

摘要

Apparatus for controlling exhaust gas recirculation in an internal combustion engine employs a first control valve in an exhaust gas recirculation passageway, a second control valve in an air conduit connecting the intake passage to atmosphere through selective restriction means, and a regulating valve responsive to differential vacuum intensities for actuating the control valves. The restriction means comprise a plurality of individual restrictions one or more of which are selectively put into operation depending upon engine operating parameters such as coolant temperature and driving speed.