柴油机电控EGR阀卡滞失效分析

Sticking Failure Analysis of Electronic Control EGR Valve

针对某柴油机电控EGR阀在试验中出现卡滞故障,拆解EGR阀驱动腔,发现里面积水严重,而驱动腔里面的冷凝水在寒冷环境下结冰,冻住中心杆,导致EGR阀卡滞。通过增加一道密封圈,采用双密封圈设计,并在两道密封圈之间增加泄压孔、泄压槽,泄压孔与大气连通,从中心杆上窜的水气、废气经过第一道密封圈后,通过泄压孔排入大气,防止进入驱动腔里面。经台架耐久试验和整车试验验证,EGR阀未再出现卡滞故障,延长了EGR阀的使用寿命。

The problems of sticking are often presented in vehicle test of electronic control EGR valve,through dismantling the driven cavity of EGR valve,serious water was found in it,and the condensate water of driven cavity froze in cold conditions,froze the central axis,resulting in the EGR valve sticking.By adding a seal ring,adopting double sealing ring design,and adding pressure relief hole and pressure relief groove between two sealing rings,the pressure relief hole,pressure relief groove and atmosphere are connected,the water vapor and waste gas channeling from the central axis pass through the first sealing ring,through the pressure relief hole into the atmosphere,preventing it entry into the driven cavity.The bench durability test and vehicle test show that the EGR valve does not appear stuck fault again,which extends the service life of the EGR valve.