| 摘要 |
<p>An exhaust emission controlling apparatus containing NOx absorbent (18) disposed in an exhaust passage (17) of an internal combustion engine (1) and having a control circuit (30) for controlling the quantity of injected fuel of the engine (1). In order to cause the NOx absorbent to emit the whole quantity of NOx absorbed at the previous stop of the engine during the period from the start of the engine till the first leans air-fuel ratio operation and to reduce the emitted NOx, the control circuit (30) increases the quantity of fuel supplied to the engine, and carries out a rich air-fuel ratio operation. This untreated NOx is prevented from being emitted from the NOx absorbent (18) at the start of the engine. Because the lean air-fuel ratio operation can be started in a state where the NOx absorbent (18) hardly absorbs NOx, the absorption capacity of the NOx absorbent can be utilized to the maximum.</p> |
