柴油机活塞组件结构参数对其密封性能的影响

以一款非道路高压共轨柴油机为研究对象,结合活塞温度场试验研究,建立了活塞组件运动学模型。着重研究了不同配缸间隙、开口端倒角对柴油机窜气量及缸内润滑油消耗的影响规律,运用响应曲面法分析了活塞环开口间隙对窜气量的影响,在此基础上对顶环及二环开口间隙参数进行优化,得到最优解。分析结果表明:配缸间隙的增大使得润滑油消耗增大,最大增幅为7.54%,配缸间隙对窜气量影响较小。顶环开口端倒角对窜气量影响较为明显,顶环开口端倒角从0增加到1mm,窜气量增大13%。顶环及二环开口间隙对柴油机窜气量影响具有线性关系,油环开口间隙对柴油机窜气量影响较小。顶环开口间隙0.42mm、二环开口间隙0.48mm为最优解,此时窜气量为13.11L/min。

Influence of Piston Component Structural Parameters on Sealing Performance of a Diesel Engine

A non-road high-pressure common rail diesel engine was taken as the research object. Based on the result of piston temperature field test, a piston dynamic model was established. The influence of different cylinder clearances and piston ring end gap chamfers on diesel engine blow-by and oil consumption was emphatically studied. The response surface method was used to analyze the influence of the piston ring end gap on blow-by. Based on the result, optimize the end gap of top ring and the second ring to obtain the optimal solution. The results indicate that, oil consumption increases with the increase of the cylinder clearances, and the largest increase is 7.54%. Cylinder clearance has little effect on the blow-by while piston ring end gap chamfer has significant influence on blow-by. Blow-by increased 13% when top ring end gap chamfer increased from 0 to 1mm. The end gap of the top ring and the second ring has a significant linear relationship with the blow-by while the end gap of oil ring has little influence on blow-by. The optimal solution appears when the end gap of top ring is 0.42mm and the end gap of second ring is 0.48mm. At this moment, the blow-by is 13.11L/min.