在发动机装配、维修和保养时,往往需要调整、校对气门间隙(以下简称调对)。实施这项工作的方法很多,其关键在于如何判断发动机各缸处在什么冲程,从而确定哪些气缸的进、排气门处于可调对状况。一般按曲轴转角推算各缸工况的方法不仅繁琐,而且难于记 In the engine assembly, repair and maintenance, often need to adjust, check the valve clearance (hereinafter referred to as the tune). There are many ways to carry out this work. The key is how to determine the stroke of each cylinder in the engine so as to determine which cylinder’s inlet and exhaust valves are adjustable. Calculating the operating conditions of each cylinder according to the crank angle is not only cumbersome but also hard to remember