发动机进气歧管支架疲劳开裂分析与优化

Analysis of Engine Intake Manifold Support Fracture and Optimization

针对某1.5 L自然吸气发动机在台架试验过程中出现进气歧管固定支架开裂的问题,开展了原因分析及设计优化。电镜分析结果表明,开裂支架断口处存在疲劳辉纹,经发动机台架振动测试及试验边界排查发现进气歧管远端振动大导致共振是支架开裂的主要原因,将支架材料由SUH409L调整为QT500,并进行了仿真及试验验证,进气歧管支架均未发生开裂现象,确定了方案的有效性。

This paper analyzed the cause of a 1.5 L naturally aspirated engine’s intake manifold mounting support cracking in bench test and design was optimized.The electron microscope analysis results show that fatigue cracks exist on the fracture surface of the failed support,and the main cause of the support cracking is found to be the resonance caused by the large vibration at the far end of the intake manifold through engine bench vibration test and test boundary checking.The material of the support was adjusted from SUH409L to QT500,simulation calculations and experimental verification were conducted on the new support,and no cracking was found on the new support.