柴油机飞轮壳子模型法强度分析与结构改进

Strength analysis of the flywheel housing of a diesel engine based on submodel method and the structure improvement

为解决柴油机台架耐久试验过程中飞轮壳频繁断裂故障,建立有、无台架排气管路的飞轮壳计算模型,对飞轮壳进行静力学分析和高周疲劳强度分析;基于子模型法分析各部分结构对飞轮壳强度影响,根据分析结果对飞轮壳结构进行优化。结果表明:试验台架对发动机状态有较大影响,在进行试验时应充分考虑台架各部件对发动机的影响并加以防控;螺栓连接的根部疲劳强度较低,易形成初始裂纹,进一步导致疲劳破坏;增加飞轮壳连接螺栓的旋合长度、改进搭子中间结构后,飞轮壳断裂故障得到解决。

In order to solve the frequent fracture failure of flywheel housing during diesel engine bench durability test,the calculation model of flywheel housing with and without bench exhaust pipe is established,and the influence of bench on the strength of flywheel housing is compared and analyzed.The static analysis and high cycle fatigue strength analysis are carried out for the flywheel housing.The influence of the structure of each part on the strength of the flywheel housing is analyzed based on the submodel method,and the flywheel housing structure is optimized according to the analysis results.The results show that the test bench has a great influence on the engine state,and the possible influence of each facility on the engine should be fully considered and controlled during the test.The root fatigue strength of bolt connection is low,which leads to further fatigue failure after initial crack.After the test verification,the flywheel housing fracture fault is solved by increasing the screw-in length of the connecting bolts of the flywheel housing and improving the intermediate structure of the lap.