| 摘要 |
PROBLEM TO BE SOLVED: To improve knocking detecting accuracy of an internal combustion engine by providing with two knocking generation judging means for judging knocking generation by detection of iron current in a combustion chamber and detection of vibration of a cylinder block, and controlling an ignition timing by the knocking generation judging means according to an operating region. SOLUTION: An iron current detecting circuit 10 and a reverse amplification circuit 20 are provided, and the output of the reverse amplification circuit 20 is taken in a CPU 43 through a master circuit 30, a band pass filter 41, and an integrating circuit 42. The output of a vibration sensor 46 installed on a cylinder block is taken in the CPU 43 through a peak hold circuit 47. Normally, iron current generated when mixture in a combustion chamber is burnt is detected, and generation of knocking is judged. When the internal combustion engine is provided in a high rotating speed operation region in which it is difficult to extract knocking vibration composition from the ion current signal due to generation of noise by LC resonance in an ion current passage, vibration of the cylinder block is detected, and generation of knocking is judged. |
