| 摘要 |
PURPOSE:To prevent an increase of knocking noise and a wrong decision of knocking, by measuring a knocking pulse width to obtain a detection knocking frequency and adjusting a predetermined value, used for deciding the knocking, to be increased and decreased in accordance with the knocking frequency. CONSTITUTION:A filter circuit 2, which allows only a knocking frequency component of the output signals of a knocking detector 1 to pass through, is provided, and a knocking detection signal, passing through this circuit 2, is compared by a comparator 5 with a signal which is input via a resistor ladder showing a reference level. A decision pulse, output from this comparator 5, is input to a microcomputer 6 counting the number. And a control device, deciding knocking to be generated when the above counted value reaches a predetermined value, corrects a value of knocking control factor of the ignition timing or the like. While here the control device, measuring a width of the decision pulse to obtain a detection knocking frequency, adjusts the above described predetermined value is accordance with a value of the knocking frequency. |
