Device for purifying the exhaust gas of an internal combustion engine

Claim 1

A device for purifying the exhaust gas of an internal combustion engine comprising a particulate filter arranged in the exhaust system, on which the trapped particulates are oxidized, wherein said engine can be operated in a first operating mode in which it is given priority to improve the fuel consumption rate thereof and a second operating mode in which it is given priority to regenerate said particulate filter to oxidize said trapped particles, and one of said first operating mode and said second operating mode is selected to operate said engine at need, wherein said engine can carry out low temperature combustion, in which an amount of inert gas supplied into the combustion chamber is larger than an amount of inert gas causing the maximum amount of produced soot and thus no soot at all is produced, and normal combustion in which an amount of inert gas supplied into the combustion chamber is small than the amount of inert gas causing the maximum amount of produced soot, said engine carriers out said low temperature combustion in a low engine load operating area when said first operating mode is selected, said engine carries out said normal combustion in middle and high engine load operating areas when said first operating mode is selected, said engine carries out said low temperature combustion in the low engine load operating area when said second operating mode is selected, said engine carries out a sub fuel injection and delays the starting time of main fuel injection in the middle engine load operating area when said second operating mode is selected, and said engine carries out said normal combustion in the high engine load operating area when said second operating mode is selected.

Claim 2

A device for purifying the exhaust gas of an internal combustion engine comprising a particulate filter arranged in the exhaust system, on which the trapped particulates are oxidized, wherein said engine can be operated in a first operating mode in which it is given priority to improve the fuel consumption rate thereof and a second operating mode in which it is given priority to regenerate said particulate filter to oxidize said trapped particles, and one of said first operating mode and said second operating mode is selected to operate said engine at need, wherein said engine can carry out low temperature combustion, in which an amount of inert gas supplied into the combustion chamber is larger than an amount of inert gas causing the maximum amount of produced soot and thus no soot at all is produced, and normal combustion in which an amount of inert gas supplied into the combustion chamber is small than the amount of inert gas causing the maximum amount of produced soot, said engine carriers out said low temperature combustion in a low engine load operating area when said first operating mode is selected, said engine carries out said normal combustion in middle and high engine load operating areas when said first operating mode is selected, said engine carries out said low temperature combustion in the low engine load operating area when said second operating mode is selected, said engine carries out a sub fuel injection and delays the starting time of main fuel injection in the middle engine load operating area when said second operating mode is selected, and said engine carries out said normal combustion in the high engine load operating area when said second operating mode is selected.