5 双金属片式附加空气阀的检测5.1 双金属片式附加空气阀结构与工作原理双金属片式附加空气阀由双金属片、电热丝及阀门等组成(图3-43)。双金属片通过阀门控制旁通空气道的开闭。发动机冷起动时,双金属片使阀门处于最大开启位置。此时,旁通空气道的通过截面最大,附加空气量也最多, 5 bimetal additional air valve detection 5.1 bimetallic additional air valve structure and working principle Bimetallic additional air valve from the bimetal, heating wire and valves and other components (Figure 3-43). Bimetal through the valve control bypass air duct opening and closing. When the engine starts cold, the bimetal retains the valve in its maximum open position. At this point, bypass air passage through the largest section, additional air volume is also the largest,