| 摘要 |
In an engine 3, the phase of an intake camshaft 6 and/or an exhaust camshaft 7 for opening and closing intake valves 4 and/or exhaust valves 5 can be changed relative to a crankshaft 9, and NOx produced during lean-burn operation is occluded by a NOx occlusion catalyst 14. An ECU 2 of a control device 1 increases the amount of fuel such that an air-fuel ratio A/F used during the lean-burn operation is enriched by an enrichment amount R1, to thereby purge the NOx occlusion catalyst of NOx occluded therein and controls to change the phase CAIN of the intake camshaft 6 towards the advance side relative to the crankshaft 9.
|
