The rocker arm pivots around its supporting shaft so that the valve end of the rocker arm is forced downward. This downward movement forces the valve to move downward off its seat so that it opens.

• 摇臂围绕支承轴旋转,气门与摇臂相对应的一端压下。向下的运动使气门向下移动离开气门座,气门被打开。