任全水，马传京，朱云峰，孙程龙，田志松

宁波吉利罗佑发动机零部件有限公司，浙江 宁波  315336

摘要：针对汽油机在北方地区冬季特定工况常发生的机油稀释问题，分析机油稀释的危害及产生原因，研究低温环境低速工况对汽油机机油稀释的影响。研究发现，汽油机在低温环境、低速工况运行时，机油稀释的主要影响因素为燃油湿壁和燃油蒸发速度。选择低温挪车和短距离行驶工况，设计试验方法和流程，在冬季漠河汽车试验场进行低速工况机油稀释试验验证。试验结果表明：经过64个挪车工况，车辆行驶3.2 km后，最大机油稀释率为11.4%；经过20个短距离行驶工况，车辆行驶100 km后，最大机油稀释率为7.8%。研究结果可为汽油机在低温环境中的正常使用提供参考。

关键词：汽油机；低温环境；低速工况；机油稀释

Abstract：Aiming at the problem of oil dilution of gasoline engine under specific working conditions in North China in winter, the harm and causes of oil dilution are analyzed, and the influence of low-temperature environment and low-speed working conditions on oil dilution of gasoline engine is studied. Low-temperature moving and short-distance driving conditions are selected to design the test process which is used for test verification of oil dilution under low-speed conditions in Mohe automobile test site in winter. The results show that the maximum engine oil dilution rate is 11.4% after 64 moving conditions and driving for 3.2 km. After 20 short-distance driving conditions and 100 km driving, the maximum oil dilution rate is 7.8%. The research results can provide valuable reference for the normal use of gasoline engine in low temperature environment.

Keywords:gasoline engine; low-temperature environment; low-speed operating condition; oil dilution