Device for knock detection in an internal combustion engine

摘要

A device for detecting knocking of an internal combustion engine which, even when spike noise is generated, does not erroneously detect it as knocking. An ionic current signal detected by an ionic current detecting unit 17 is separated into a knocking frequency component passing through a band-pass filter 32 and frequency components other than the knocking frequency component passing through a low-pass filter 321 and a high-pass filter 322. When the knocking frequency component is higher than a predetermined level, it is determined that the knocking is occurring. When the frequency component other than the knocking frequency component is higher than the predetermined level, it is regarded that the spike noise is generating, so that the generation of spike noise will not be erroneously determined as knocking.