Patent ID: 6932062

Claim:
A compression ignition internal combustion engine that performs switching between compression ignition combustion mode and spark ignition combustion mode, the compression ignition internal combustion engine comprising: at least one combustion chamber; an intake passage and an exhaust passage connected to the combustion chamber, respectively; intake means provided at a position along the intake passage for opening and closing the intake passage; exhaust means provided at a position along the exhaust passage, and is driven by a cam, for opening and closing the exhaust passage, the exhaust means opening the exhaust passage for a period of at least a portion of an exhaust stroke, and for a period of at least a portion of an intake stroke, during the compression ignition combustion mode and during the spark ignition combustion mode; and exhaust gas recirculation preventing means provided at a position along the exhaust passage, for opening and closing the exhaust passage, the exhaust gas recirculation preventing means recirculating exhaust gas to the combustion chamber by opening the exhaust passage at least during the intake stroke during the compression ignition combustion mode, the exhaust gas recirculation preventing means preventing the recirculation of the exhaust gas to the combustion chamber by closing the exhaust passage for a period at least when the exhaust means is open in the intake stroke during the spark ignition combustion mode.