| 摘要 |
PURPOSE:To suppress the unnecessary spark delay control by the post-knock detection and improve reliability by correcting the threshold value based on the knock level and noise level, comparing the threshold value and knock level after correction, and judging the presence of knock. CONSTITUTION:The peak level P of the output A is generated for every ignition timing by a peak holding circuit 2 from the output A of a knock sensor 1 for each cylinder. The preset threshold value TH and the peak value P are compared by a knock judging section 17, if P>TH, the spark delay quantity thetaR is calculated by a spark delay quantity calculating section 18 and outputted to an ignition timing controller 19. An operation state processing unit 12 determining the operation region D based on the outputs of a crank angle sensor 3 and a load sensor 11 is provided, and the threshold value corresponding to the operation state D is read out from the first ROM 13. This threshold value is corrected 20 by the noise level N corresponding to the operation region D read out from the second ROM 14, and the threshold value after correction is applied to the knock judging section 17. |
