Abstract: For the poor shift performance problems of a car, through the fault tree analysis of the various influence factors in detail, the fundamental reason is design flaws exist in the angel between limit gear shift drawing and shift rock arm, and unreasonable design of clearance compensation structure for transmission system. After theoretical analysis and actual loading verification, optimizing the angel between shift wire drawing and shift rocker arm, optimizing clearance compensation structure of transmission system. It improves the shift performance of the car, and provides reference for solving such problems in the later stage.

Key words: Transmission system; Shift performance; Shift wire drawing; Optimization design

摘要： 文章针对某自动挡车型换挡性能较差问题，通过对各种影响因素进行详细的故障树分析，发现其根本原因 为极限挡位下换挡拉丝与换挡摇臂之间夹角存在设计缺陷，并且变速系统间隙补偿结构设计不合理。经过理论分析 及实际装车验证，通过优化换挡拉丝与换挡摇臂之间夹角，优化变速系统间隙补偿结构，提升了整车换挡性能，并 为后期解决类似问题提供参考依据。

关键词: 变速系统；选换挡性能；换挡拉丝；优化设计