增压发动机排气系统密封结构优化研究

Research on Sealing Structure of Turbo Engine Exhaust System

针对涡轮增压发动机排气系统存在的法兰高温变形和密封垫片压缩回弹性能差的问题,结合CAE有限元分析和密封垫片试验数据,提出法兰结构优化方法和变凸筋的密封垫片结构设计,并通过发动机台架和车辆耐久性试验,验证了密封的有效性和持久性。该优化方法通过软化局部法兰,使得排气歧管法兰各处刚性趋于一致,从而解决排气歧管和增压器结合面漏气问题;根据内部密封介质压力和密封结合面法兰在热循环中变形量情况,在法兰不同密封区域选择不同的凸筋结构,实现了持久可靠的密封效果。

For the problems of flange deformation at high temperature and poor compression-recovery performance of the gasket on turbo engine exhaust system, the flange structure optimization method and the multi-bead gasket structure design were proposed based on CAE calculation and gasket test data. Robust and durable sealing performances were validated by engine bench test and vehicle durability test. The flange tial flange to achieve consistent rigidity, and the gas 1 design was optimized by means of softening exhaust manifold par- eakage problem between exhaust manifold and turbocharger was solved. According to inner media pressure and flange deformation in thermal cycle, different bead structures were designed on different sealing zone, and robust and durable sealing performance between exhaust manifold and turbocharger was achieved.