柴油机缸套表面微沟槽织构润滑性能仿真分析

Simulation and Analysis on Lubrication Performance of Surface Micro-Groove Texturing on Cylinder Liner in Diesel Engine

针对缸套表面织构微沟槽形貌,建立了缸套-活塞环摩擦副混合润滑理论模型,并采用MATLAB编程计算来分析微沟槽形貌参数对其润滑摩擦性能的影响规律。结果表明:缸套表面微沟槽可以形成很好的油膜压力,有效地改善缸套-活塞环间的润滑状态;随着微沟槽角度的增大,最小膜厚比逐渐增大,其润滑效果也越来越好,综合考虑摩擦润滑性能和机油耗性能情况下,最佳的微沟槽角度为60°。在上止点附近,面积占有率变化Sp对量纲一摩擦力影响较大;在其他区域,面积占有率对摩擦力影响不大;综合考虑油膜厚度与摩擦力,当Sp=0.15时效果最好。随着微沟槽深宽比e的增大,量纲一摩擦力不断增大,当e从0.025增大到0.150时,平均量纲一摩擦力增大了2.3倍,但深宽比过大,润滑效果将会减弱。研究结果认为,最佳深宽比的范围为0.05～0.08。

Based on surface micro-groove texturing on cylinder liner, a mixed lubrication model of cylinder liner-piston ring was established, and the influence of micro-groove parameters on the lubrication performance was calculated by using MATLAB programming. The results show that the surface groove can form good film pressure, which effectively improves the lubrication state between cylinder liner and piston ring. And with the angle of micro-groove increases, the minimum oil ratio increases gradually, and the lubrication effect is getting better and better. Meanwhile synthetically considering the lubrication performance of friction and engine oil consumption performance, the best angle of micro-groove is affirmed as 60°. The changing of area density has great influence on the dimensionless friction force nearby the TDC, but has little influence on the other areas. Then the optimal area density is Sp =0. 15. The dimensionless friction force increases continually with the increases of depth-to-width ratio, when e increases from 0. 025 to 0. 15, the average dimensionless friction force increases 2. 3 times, and if the depth- to- width is too large, the lubrication effect will be weakened, the optimal depth-to-width ratio is as e=0.05-0.08.