| 摘要 |
<p>PURPOSE:To effectively activate an exhaust purifying catalyst through the retarding of ignition timing and to avoid wasteful retarding correction. CONSTITUTION:Exhaust temperatures T1, T2 are detected upstream and downstream of a catalyst, respectively, (S1), and the difference DELTAT between the exhaust temperatures T1, T2 is computed (S2). Then a fundamental amount of correction of retard R is set according to the downstream exhaust temperature T2 (S3). It is determined whether or not the catalyst has reached its activation temperature according to the downstream exhaust temperature T2. Correction factors Cr, Cr' for correcting and setting the fundamental amount of correction of retard R are set with different characteristics according to the temperature difference DELTAT (S5, S7). The fundamental amount of correction of retard R is corrected and set using the correction factors CR, CR' (S6, S8) and ignition timing is retarded according to the correction results (S9).</p> |
