加工偏差对柴油机气门顶杆强度的影响分析

The Influence Analysis of the Machining Error to Valve Mandril's Strength for Diesel

在对某型柴油机气门顶杆断裂原因理化分析的基础上,对加工不合格气门顶杆的强度、模态、稳定性、疲劳安全系数及寿命进行了理论计算,结果表明:加工产生的偏差对气门顶杆的模态及稳定性的影响不会导致顶杆发生与外界载荷的共振及失稳,但由于加工误差导致的应力集中会降低顶杆的疲劳安全系数进而使其疲劳失效,顶杆理论计算的寿命与实际运行时间较为吻合,所得结论为判断顶杆的故障原因提供了支持。

Based on the physical and chemistry analysis to the rupture Valve Mandril of the diesel, models for computing the strength, mode, stability, fatigue safety factor and life of the disqualification valve mandril are built. The result indicated that the error has nothing to do with the mode and stability, but the stress convergence produced by machining error can depress the fatigue safety factor of the mandril and lead to fatigue disabled. The estimate life is closed to the actual runtime. The study provides support for judging the reason for the valve mandril＇ s rupture.