重型车辆柴油机气缸当量漏气面积检测模型研究

针对非拆解状态下重型车辆柴油机压缩过程缸内漏气状况难以定量检测的问题，建立柴油机缸套-活塞环漏气过程的双环几何简化模型。通过分析压缩行程中缸内气体的流量与压力变化，推导活塞环当量漏气面积的数学表达式。分析缸套-活塞环热变形对漏气面积的影响，建立缸套-活塞环的当量漏气面积检测模型。利用柴油机保险期试验的拆解检测数据验证模型的准确性。结果表明：当量漏气面积计算结果与柴油机缸套磨损状况一致，与柴油机工况相关性较低，该模型能够较为准确地反映柴油机当前的漏气状况。

Research on Equivalent Air Leakage Area Detection Model of Heavy Vehicle Diesel Engine

A double-ring geometric simplified model of the leakage process of diesel engine cylinder-piston ring is established for quantitatively detecting the leakage condition of diesel engine in the non-dismantling state. The mathematical expression of leakage area of piston ring is deduced by analyzing the flow and pressure changes of the cylinder air during compression stroke. The influence of thermal defor- mation of piston ring on the leakage is analyzed, and an equivalent air leakage area detection model of cylinder- piston ring is established. The results show that the equivalent air leakage area is consistent with the wear condition of diesel engine cylinder liner, the correlation with the working condition of diesel engine is low, and the proposed model can reflect the current leak condition of diesel engine.