Exhaust purification apparatus of an internal combustion engine with a cooling unit

摘要

Exhaust gas purification unit (1) comprises a catalyst (3), a nitrogen oxides storage catalyst (5), an exhaust gas temperature sensor (6) and an exhaust gas cooling unit (4) arranged between the catalysts to regulate the temperature of the exhaust gas stream flowing through the nitrogen oxides storage catalyst. Preferred Features: The exhaust gas cooling unit has an exhaust gas flap (8) and a bypass line (9). The flap can be controlled and is arranged in the branch position of the bypass line of the cooling unit.