모터링 전류 파형 분석에 의한 기관의 압축 압력 불균형 분석

Compression pressure of individual cylinder affects firing pressure, brake torque, emission, combustion noise and many other parameters. Individual compression pressure of each cylinder has been measured and evaluated by mechanical pressure sensor which should be applied to spark plug or glow plug hole for gasoline or diesel engine. As modern engine becomes to have many cylinders and V-type block and also to have complex system components, to take out spark plugs or glow plugs to measure compression pressure of all cylinders is not easy as it was. Furthermore, in order to measure cylinder pressure with conventional pressure sensor, additional adapter part is needed to connect mechanical pressure sensor to cylinder head which has various size and shape of hole for spark plug or glow plug. This study describes and suggests new methodology to measure cylinder compression pressure through analysis of current consumption of start motor during cranking phase. With this new methodology, possibility to detect leaky cylinder with very high accuracy was observed.