宋树峰，王国华*，付强，郭金朋，王友然

滨州渤海活塞有限公司，山东滨州256602

 摘要：为解决某工程机械用天然气发动机热机试验中怠速工况机油消耗偏高的问题，分析活塞组件机油消耗产生的原因，通过有限元分析得到活塞温度场边界条件，利用动力学软件建立活塞与活塞环组的动力学模型，设计5种活塞优化方案并计算不同方案下活塞摆角及机油消耗，得到最优方案，并通过台架试验验证计算结果。结果表明：优化活塞裙部型线、调整销孔偏心、减小配缸间隙、降低活塞环及环槽粗糙度可以降低发动机在怠速工况时的机油消耗，优化后整机机油消耗降低了17.93 g/h。该研究可以为天然气发动机活塞的优化设计提供参考。

 关键词：天然气发动机；活塞参数；机油消耗量；怠速

 Abstract：To solve the high engine oil consumption problem of a natural gas engine under idle conditions in the engine test，the causes of oil consumption of piston assembly are analyzed,the piston temperature field and boundary conditions are obtained by finite element analysis.A dynamic model of piston and piston ring group is established using dynamics analysis software, and 5 kinds of optimization scheme are designed. The pendulum angle and the engine oil consumption are calculated,the optimal scheme is obtained,and the results are validated by bench test.The results show that the engine oil consumption of the engine at idle speed can be reduced by optimizing the piston skirt profile, adjusting the eccentricity of the pin hole ,reducing cylinder clearance ,reducing piston ring and ring groove roughness.The engine oil consumption of the whole machine is reduced by 17.93 g/h after optimization.The study can provide reference for the optimal design of natural gas engine piston.

 Keywords:natural gas engine; piston parameter; engine oil consumption;idle speed