某型车用柴油机机体缝合螺栓的可靠性增长研究

摘要

针对某型车用柴油机机体缝合螺栓存在的断裂问题,研究机体缝合螺栓的失效模式及其失效机理,设计机体缝合螺栓模拟试验装置,进行机体缝合螺栓振动试验,实现机体缝合螺栓断裂失效的复现.在此基础上,研究机体缝合螺栓的可靠性增长措施及其有效性,将改进后的机体缝合螺栓安装在柴油机上进行应用验证.研究结果表明:机体缝合螺栓的失效模式为疲劳断裂,机体缝合螺栓在工作时发生共振是导致其断裂的原因;机体缝合螺栓采取可靠性增长措施后在安装状态下的固有频率得到显著提高,能够有效避免因共振引发的断裂失效.%For the reliability of closed blots for automobile diesel engine body,the failure mode and its failure mechanism of closed blot is studied.A test equipment of closed blots is designed.The vibration experiment is done for closed blot for diesel engine body,and the fault recovery of closed blot with the fatigue mode is completed.The measures for improving the reliability of closed blots are studied.The improved closed blot is assembled on the diesel engine body,and its reliability is validated through application.The result shows that the failure mode of closed blot for diesel engine body is a vibration fatigue,and the resonance is the reason for the failure of closed blot.After the measures for improving the reliability are adopted,the vibration frequency of closed blot is improved obviously,and it can avoid the resonance effectively.