CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To optimally maintain a torque fluctuation amount while preventing a NOxemission amount from a catalyst from exceeding its allowable upper limit. SOLUTION: In an internal combustion engine, an amount of NOxflowing in the catalyst and the torque fluctuation amount are changed by changing ignition timing. Ignition timing with approximately minimum torque fluctuation amount out of ignition timing where the NOxemission amount from the catalyst does not exceed its allowable upper limit is acquired in advance as a function of a NOxcleaning ratio of a main catalyst 33, and is stored as target ignition timing. The NOxcleaning ratio of the main catalyst 33 is acquired from outputs of NOxsensors 36, 37, the target ignition timing is acquired based on the NOxcleaning ratio, and actual ignition timing is controlled to match with the target ignition timing. COPYRIGHT: (C)2008,JPO&INPIT