Abstract: The head position of the vertical pin type V-thrust rod is a typical ball seat-flange connection structure, and the bolt plays an important role in ensuring the stability of the product. In order to solve the problem of bolt failure at the head position of the V-thrust rod used in heavy truck, this paper starts from the initial design of the bolt and the possible causes of bolt loosening, combined with theoretical calculations and computer aided engineering (CAE) analysis of vibration, and determines that the main reasons for the failure are the insufficient initial torque design and the self-loosening behavior under the vibration conditions. Based on this, this paper formulates targeted improvement measures, and selects the optimization scheme through transverse vibration test comparison, which not only solves the practical problems, improves the stability and durability of the product, but also provides guidance for the optimization design of subsequent bolted joints.

Key words: V-type thrust rod; torque; bolt looseness

摘要： 竖销型 V 型推力杆球头位置为典型的球座-法兰连接结构，其中螺栓作为重要的连接部 件，对于保证产品的稳定性具有重要作用。为解决某款重型卡车用 V 型推力杆球头位置的螺 栓失效问题，文章从螺栓的初始设计、螺栓松动的可能原因入手，结合理论计算，振动的计 算机辅助工程（CAE）分析等，确定失效的主要原因为初始扭矩设计不足以及螺栓在振动工 况下的自松动行为。基于此，文章针对性制定了改进措施，并通过横向振动试验对比选定了 优化方案，不仅解决了实际问题，提高了产品的稳定性与耐久性能，也对后续螺栓连接的优 化设计提供了指导。

关键词: V 型推力杆；扭矩；螺栓松动