Engine exhaust gas recirculation control system

摘要

An exhaust gas recirculation control system for an engine, in which the recirculation rate is controlled so as to have a desired value by an exhaust gas recirculation control valve disposed between the exhaust pipe and the inlet pipe of the engine. The control valve is controlled by an electronic control unit which determines the desired recirculation rate from a predetermined relationship based on the operating condition of the engine which is determined by the engine speed and the engine pressure as well as on the output of an oxygen sensor. The inlet pipe of the engine may be divided into two inlet paths, one of which has mounted thereon the oxygen sensor.