ABNORMAL COMBUSTION DETECTION APPARATUS FOR INTERNAL COMBUSTION ENGINE

An object of the present invention is to provide a technology that enables an abnormal combustion detection apparatus for a spark ignition internal combustion engine having a plurality of cylinders to detect abnormal combustion such as pre-ignition and knocking with improved accuracy. To achieve the object, according to the present invention, in an abnormal combustion detection apparatus for a spark-ignition internal combustion engine that determines or detects the occurrence of abnormal combustion by comparing a vibration intensity obtained from a measurement signal of a knock sensor and a determination threshold, when the occurrence of abnormal combustion is detected, the apparatus corrects a determination threshold for the next cylinder using as parameters the peak value of the vibration intensity at the time of the occurrence of abnormal combustion and the engine speed.