| 摘要 |
PURPOSE:To obtain a knock control device for an internal combustion engine which can prevent the correction in a wrong direction of a decision level by proving a correction inhibiting means for inhibiting the correction of a knock decision level when knock strength value becomes excessively large or small. CONSTITUTION:An ignition time control circuit 8 inputs the maximum peak value in the fixed range of a signal sent from a knock sensor 6 as knock strength value through a peak holding circuit 7. After comparing the above- mentioned knock value with a knock decision level, the spark regress quantity of the ignition time is computed to be sent as output for controlling the ignition time, and the updating of a parameter for detecting a knock state is simultaneously executed, and moreover the decision is given on whether conditions for correcting the knock decision level can be satisfied or not. Namely, when the middle value of the distributed knock strength values is within their fixed range, the knock decision level is corrected, and when the above-mentioned middle value is out of the above fixed range, the knock decision level is not corrected. Thus the wrong correction of the knock decision level can be prevented. |
