关键词: 轻型客车；钢板弹簧；断裂失效

Abstract: The leaf spring of a light passenger car frequently breaks problems during the durability test of the vehicle. Through macro and micro analysis of the fracture surface, chemical composition analysis, hardness test, metallographic structure detection and analysis, as well as analysis of the position of the milling step and the stress characteristics of the leaf spring, this paper determines the root cause of the fracture of the leaf spring and formulates improvement measures, and is verified through the bench test and vehicle durability test. The results show that the milling range on both sides of the leaf spring lug is too long, resulting in milling steps at the R corner of the leaf spring, which further increases the stress concentration here and causes the leaf spring to break. The issue is solved by reducing the milling length on both sides of the leaf spring lugs.

Key words: Light passenger car; Leaf spring; Fracture failure