The invention of the internal combustion engine can be detected up to a cylinder misfire has occurred in a diesel engine or a gas engine and a gasoline the engine also detects a misfire which may occur during driving, such as an internal combustion engine as the well-cylinder engine with a simple structure It relates to a misfire detection method and apparatus,
Misfire detection method for an internal combustion engine includes the steps of detecting the rotational angular velocity and the reference top dead center position of the cylinder axis of rotation of the engine; By comparing the frequency in accordance with the rotational speed of the rotational frequency and the engine according to the rotational angular velocity and determining whether a misfire occurs; When a misfire occurs and a confirmation step of filtering so as to pass only a frequency corresponding to the rotational speed of the engine of the signal corresponding to the rotational angular velocity; After dividing the pulse signal corresponding to the top dead center position of the reference cylinder number of the cylinder of the cylinder position corresponding to the peak value of the filtered signal band-pass filter comprising: determining a misfire occurs cylinder; and characterized in that it comprises a,
Misfire detection apparatus for an internal combustion engine, the detector 10 for detecting the rotational angular velocity of each of the top dead center position and the reference cylinder of the engine and the rotating shaft; Analyzing the detection signal and the reference top dead center of the rotational angular velocity signal detected by the cylinder 10 and the process judges whether or not misfire occurs and the signal processor 20 for detecting a misfire occurs the cylinder; characterized in that it comprises a. Specifically, the signal processing section 20 is configured to analyze and process the detected pulse signal by the rotation angle velocity detection unit 11 in the time domain and the frequency domain should determine whether a misfire occurred in accordance with the change of the frequency showing a peak as well as the reference cylinder dividing the interval between the pulse signal detected by the detector 12 as the number of the cylinder and, after a match so as to correspond to the top dead center position of each cylinder, determining a cylinder matched to the peak position of the band-pass filter signal to a misfire occurs cylinder will.
Accordingly, whether or not the misfire occurred in the internal combustion engine, as well as can prevent a serious accident, such as an internal combustion engine stop by to be prepared to detect a misfire occurs in the cylinder is able to early as well as to increase the service life of the engine.