Automobile exhaust gas recirculating system

Abstract

An exhaust gas recirculating system for a combustion engine has at least one cylinder communicating with a source of combustible air-fuel mixture through at least one intake port adapted to be selectively closed and opened for effecting the interruption and admission of the supply of the combustible mixture into the combustion chamber, the cylinder also communicating with an exhaust system through first and second exhaust ports both adapted to be selectively opened and closed. The exhaust gas recirculating system includes an intake valve for selectively opening and closing the intake port, first and second exhaust valves each for selectively closing and opening the associated first and second exhaust ports, wherein the first exhaust valve is operable to completely close the associated first exhaust port subsequent to the complete closure of the second exhaust port by the associated second exhaust valve, an exhaust shutter valve for selectively opening and closing a passage extending between the first exhaust port and the exhaust system, and a control unit for controlling the shutter valve according to an engine operating condition to adjust the amount of a portion of the exhaust gases allowed to substantially remain within the cylinder.