| 摘要 |
PURPOSE:To prevent a knocking by discriminating the cylinder which generates a knocking and performing correction to only the cylinder generating knocking when the knock level is below a predetermined value and performing the same to all the cylinders when said level is above the predetermined value. CONSTITUTION:When an engine is in operation, knocking is detected through inputting the output of a vibration sensor 3a to a knocking detection circuit 3 and comparing 11 a signal which passes BPF9 and a signal obtained by averaging 10 output of BPF9. Further, after inputting the output of a crank angle sensor 4 to a cylinder discrimination circuit 17 of a cylinder control correction circuit 7, a cylinder generating knocking is discriminated from the output of AND circuit 16 which receives the output of a circuit 3 and a comparator 14. Then, in case a knocking below the set level is generated in the first cylinder, for example, the first ignition timing decision circuit 18a is controlled for correction to the lag angle side. On the other hand, in case a knocking above the set level is generated, all the ignition timing decision circuits 18a-18d are controlled for correction to the lag angle saide. |
