| 摘要 |
PURPOSE:To make excellent knock control possible by distinguishing a specified cylinder to inhibit the improper correction of its decision level, and making the correction quantity of the knock decision level of another cylinder reflect on the knock decision level of the specified cylinder. 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, and compares the maximum peak value with a knock decision level per cylinder to compute spark regress corresponding to the above-mentioned knock decision level. Then the updating of a parameter for detecting a knock state is carried out. In addition to that, when decision level correcting condition is met, namely fixed time has elapsed after the completion of the treatment of all the cylinders on the last step, and all the cylinders are within a knock control range and also in their normal state, the constant of the decision level of the cylinder excepting a specified cylinder is determined to correct the knock decision level. The specified cylinder is corrected on the basis of the averaged constant of the decision levels of the other cylinders. Thus the correction quantity of the knock decision level of the other cylinder is reflected on the specified cylinder. |
