| 摘要 |
PURPOSE: To perform rapid activation of a catalyst as a stable operation state is maintained by effecting delay control of an ignition timing to a limit at which the fluctuation state of an engine rotation speed is kept at a value below a given value during a given time beginning with a starting, in an ignition timing control device for an internal combustion engine having an exhaust gas purifying catalyst located in an exhaust passage. CONSTITUTION: In a control unit 15 to input detecting signals from an air-fuel ratio sensor 10, a crank angle sensor 12, and a combustion pressure sensor 14, it is decided whether it is right after the starting of an engine and when it is decided that it is right after starting, when it is decided that a lapse time beginning with starting is below a given time, an engine rotation speed N is computed based on a signal from the crank angle sensor 12. Further, a fluctuation content,ΔN is computed from a difference at intervals of a given period of the engine rotation speed N. In the fluctuation contentΔN, a low frequency component by which an influence is exercised on operation is discriminated through computation of a low frequency filter. When the discriminated fluctuation contentΔN is below a given value, delay correction of an ignition timing ADV is effected by a given amountΔADV, and when it exceeds the given value, advance correction is effected. |
