INTAKE AIR QUANTITY CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To prevent combustion in an internal combustion engine from getting instable by control of a variable valve action angle system and enable evacuation travel when a variable valve timing system becomes unusual. SOLUTION: When a variable valve timing mechanism (VVT) is unusual ("YES" in S106), it is determined whether an actual valve timing VTa is larger than a valve timing advance limit value XTegr or not (S110), a target valve action angle VLt is established by switching to medium valve action angle VLmid and maximum valve action angle VLmax (S112, S114). Evacuation action angles VLmid, VLmax are valve action angles set for stabilizing combustion at each valve timing. And intake air quantity is controlled by a throttle valve under a condition that the valve action angles are fixed to the evacuation action angles VLmid, VLmax (S116, S118). Consequently, unstable combustion in the engine is prevented to enable evacuation travel. COPYRIGHT: (C)2005,JPO&NCIPI