四缸柴油机机体结构强度及缸套变形分析

Analysis on structural strength of cylinder block and deformation of cylinder linersin a diesel engine

以某四缸柴油机机体组合件为对象,对机体、气缸盖、气缸套、油底壳等多个零件、部件的组合件进行了全面的有限元分析和结构改进。在机体组合件强度分析的基础上,深入阐述了截面圆度、漏光率、圆柱度、同轴度、连续13个截面最小半径等气缸套变形评价指标的意义。并且运用这些指标对原方案及改进方案进行分析比较,得出以下结论:改进方案降低了原方案中偏高的机体隔板应力,降幅达32%已处于安全水平;改善了气缸套的变形,可以有效地提高发动机排放性能。

Taking a diesel engine as a specific object,a FEA was performed comprehensively for the assembly units including cylinder block,cylinder head,cylinder liners,sump and so on,and some improvements were made on the structure as well.Based on the analysis of strength of the assembly,some indicators to evaluate the deformation of cylinder liners were described including roundness of sections、leak rate of sections、cylindricity、axiality and inscribed column radius for 13 contiguous sections.With which the original and the improved cases were analyzed and compared and come to the conclusion： the stress of clapboard in the improved program has been reduced by 32% compared with the original one to be in a safe level;The deformation of cylinder liners has been improved which may improve efficiently the emission performance of the engine.