CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To improve driveable properties and fuel economy by suppressing torque fluctuations and reducing the frequency of rich spike control. SOLUTION: An engine 3 has a phase CAIN of an intake camshaft 6 and/or an exhaust camshaft 7 for opening/closing an intake valve 4, an exhaust valve 5 as is adjustable relative to a crankshaft 9, and a NOx absorbing catalyst 14 absorbs NOx during lean-burn operation. For NOx to be reliased from the NOx absorbing catalyst 14, an ECU 2 in a control system 1 increases fuel to enrich the air-fuel ratio A/F of lean-burn operation by an enrichment level R1 and adjusts the phase CAIN of the intake camshaft 6 relative to the crankshaft 9 to the advancing side according to the enrichment level R1 of the air-fuel ratio A/F.