某汽车门锁未通过防撬试验原因分析及改进

Reason Analysis and Improvement of a Vehicle Door Latch Failed to Meet Anti-theft Requirement

某汽车门锁未通过防撬试验,观察发现直接原因为门锁中一螺栓发生断裂。通过宏观检验、断口分析、硬度测试和金相检验等方法,对该螺栓断裂的原因进行了分析。结果表明:螺栓主要是过载受力导致了塑性断裂。据此,将螺栓强度从4.8级提高到了8.8级,改进后的门锁通过了防撬试验。

A vehicle door latch failed to pass the anti-theft test. The direct cause was the fracture of a bolt in the latch. The fracture reason of bolt was analyzed by the methods of macro examination, fracture analysis, hardness testing, metallographic examination and so on. The results showed that overload was the main reason which led to ductile fracture in the bolt. Therefore the bolt strength grade was increased from 4. 8 to 8. 8 to avoid overload. The improved vehicle door latch successfully passed the anti-theft test.