中巴水温高故障原因及改进措施

Failure Analysis and Improvement of High Water Temperature of Mini Bus

中巴系列商用车自投放市场以来,用户使用发现:该车行驶一段时间后,发动机水温超过100℃。储水罐中出现喷水现象,导致散热器严重缺水而熄火。经分析认为产生故障的原因,发动机EGR冷却器水路与整车暖风水路串联,暖风水阀关闭时,EGR冷却器冷却水气化,导散热器缺水而高温;水箱压力盖开启压力设计过小。针对以上原因,提出了改进措施。

Since mini bus series of business vehicle lauched on the market,end users found problems that,after driving for periods of time,engine water temperature goes exceed 100 ℃. Water sprays inside kettle and lead to radiator water leakage and misfire. After analysis,reasons could be found that Engine EGR cooler water circuit is connected with vehicle heater water circuit in series,when heater water valve is closed,EGR cooler coolant gasify,and leads high temperature of radiator; the open pressure design of pressure cover of water tank is too small. Some improving measures are put forward based on the above reasons.