发动机排气歧管断裂原因分析及改进

Analysis and Improvement of the Engine Exhaust Manifold Cracking

某发动机在试验过程中,出现批量排气歧管开裂故障,通过分析认为,故障产生的原因为排气歧管的安装螺栓约束使排气歧管无法膨胀,产生应力集中而开裂,并根据分析结果重新优化了排气歧管的安装螺孔直径,经过试验验证表明,改进措施是有效的。

A batch of the crack failure of exhaust manifold happened in the process of the engine test,According to the analysis,the reason of failure is that exhaust manifold constrained by assembly bolts and could not be expanded at the high temperature,Then stress concentration occurred and caused crack.Through the detail investigation and research,the diameter of exhaust manifold screw holes is re-optimized.The test result shows that this improvement is effective.