| 摘要 |
PROBLEM TO BE SOLVED: To provide a knock sensing device of internal combustion engine capable of generating good knock pulse S/N even if the ion current generating amount has changed caused by a change in the sort, etc., of the fuel, plug and the like. SOLUTION: A knock sensing device of an internal combustion engine is configured so that the vibratory component superimposed on the ion current generated by combustion of the fuel is extracted, the waveform is trimmed into pulses through comparison with the threshold, the number of pulses is calculated by a calculating means, and on the basis of the obtained result, the control of the ignition timing is conducted, wherein the arrangement includes an integration circuit 23 to make integration (charging) of the vibratory component superimposed on the ion current and a discharge circuit 24 to make discharge of a specified quantity of electric charges from the integrated (charged) electric charges, and the threshold is adjusted autonomously according to the balance of charge and discharge between the integration circuit 23 and discharge circuit 24. |
