| 摘要 |
PURPOSE:To detect misfire from the magnitude of vibration waveform arising during the misfire by using a viration sensor such as a knock sensor which is already mounted. CONSTITUTION:Vibration arising during misfire is detected by a vibration sensor 1 which is mounted on an engine, unnecessary portions are removed by a low- path filter (LPF) 2, conversion to a digital value is made by an analog-digital convertor (ADC) 3, only misfire components whose output levels change only during the misfire are picked up by a digital filter 4, and the misfire is detected by a misfire detection section 7 comparing the detection level with a criterion value which is variable with the engine speed. |
