内燃机活塞裙部-缸套间润滑油输送状况*

活塞裙部-缸套间的润滑油输送情况对内燃机活塞组件摩擦副润滑状态、润滑油消耗、排放和润滑油性能退化等都有重要的影响。结合活塞二阶运动模型、流体润滑模型和润滑油流动模型等，进行不同内燃机工况下活塞裙部-缸套间润滑油输送状况的计算，主要分析活塞向下运动行程中活塞裙部运动后气缸套表面润滑油的滞留量。结果表明，在不同工况下对应行程中润滑油滞留量的变化规律基本相同，不同时刻的润滑油滞留量不相同，活塞上下止点处的润滑油滞留量基本相同。内燃机负荷相同时，随转速增加，进气行程中和膨胀行程中后期的润滑油滞留量减少，膨胀行程前期的润滑油滞留量增加。内燃机转速相同时，膨胀行程前期的润滑油滞留量一般随负荷增加而增加，膨胀行程中后期的润滑油滞留量基本不随负荷变化，不同转速下进气行程中润滑油滞留量随负荷的变化规律不一致。

Transport of Lubricating Oil between Piston Skirt and Cylinder Liner for Internal Combustion Engine

The transport of lubricating oil between the piston skirt and the cylinder liner has important influence on the lubrication status of piston assembly frictional pair,the consumption of lubricating oil,the emission and the performance degradation of lubrication oil.Based on the models of piston secondary motion,fluid lubrication and lubricating oil flow,the transports of lubricating oil between the piston skirt and the cylinder liner at the different engine conditions are calculated.The detained lubricating oils on the surface of cylinder liner behind the movement of piston skirt in the strokes in which the piston moves downward are analyzed mainly.The results show that the change rule of detained lubricating oil is same basically in the corresponding stroke at different operating cycle,the detained lubricating oil is different at different time,and the detained lubricating oil is same basically at the top and bottom dead center.Under the condition of same load of engine,when the speed increases,the detained lubricating oil in the intake stroke and the middle and later stage of expansion stroke will decrease and the detained lubricating oil in the earlier stage of expansion stroke will increase.Under the condition of same speed of engine,the detained lubricating oil in the earlier stage of expansion stroke will increase generally with the increase of load,the detained lubricating oil in the middle and later stage of expansion stroke will not change basically against the load,and the detained lubricating oil in the intake stroke will have different change rule against the load in the different speed.