摘要 |
PROBLEM TO BE SOLVED: To simultaneously prevent discharging soot, NOx, and unburned hydrocarbon, to save fuel at the time of deceleration driving, and to avoid the decreasing of catalyst temperature. SOLUTION: This internal combustion engine simultaneously prevents discharging soot and NOx by executing low-temperature combustion wherein an EGR gas amount supplied into a combustion chamber 5 is more than the EGR gas amount at a peak of generation amount of soot, and wherein soot is hardly generated. And the internal combustion engine prevents discharging unburned hydrocarbon therefrom by oxidizing the unburned hydrocarbon discharged from the combustion chamber 5 with a catalyst 25. At the time of deceleration driving, fuel cutting is executed to save fuel. Furthermore, by executing the fuel cutting at deceleration driving and opening a throttle valve 20, decreasing temperature of the catalyst 25 owing to air passing through the combustion chamber 5 without contributing to combustion is prevented, so that reduction in oxidizing performance of the catalyst 25 with decreasing of the catalyst temperature is prevented. |