Abstract: The load distribution of the fork arms on both sides of the shift fork has a crucial impact on the shift performance and comfort of the gearbox. In this paper, according to the design requirements of the shift mechanism, the initial structure model of the shift mechanism is established and the finite element analysis is carried out. The finite element calculation results are used as the topology pre-input conditions. The topology optimization analysis of the initial structure of the shift fork is carried out by using the variable density isotropic material penalty model algorithm, and the optimal design structure of the shift fork is obtained. The part of the optimized design structure of the shift fork that does not meet the actual processing and manufacturing requirements is adjusted to obtain the final design structure of the shift fork. The numerical simulation analysis of the final design structure of the shift mechanism is carried out. Under the condition of limited design space of shifting mechanism, the load distribution of shifting fork arm is greatly optimized and the strength and durability life of shifting fork are improved. A design method for improving the robustness of asymmetric shifting fork of transmission is proposed.

Key words: Transmission; Asymmetric shift fork; Topology optimization; Robustness

摘要： 换挡拨叉两拨叉臂的载荷分配优劣对于变速箱的换挡性能及舒适性有着至关重要的影 响。文章根据换挡机构设计要求，建立换挡机构的初始结构模型并开展有限元分析，将有限 元计算结果作为拓扑前置输入条件；采用变密度各向同性材料惩罚模型算法对换挡拨叉的初 始结构开展拓扑优化分析，获得换挡拨叉的优化设计结构；对换挡拨叉的优化设计结构中不 满足实际加工制造要求的部分进行调整，得到换挡拨叉的最终设计结构；对换挡机构的最终 设计结构进行工况的数值模拟分析。在换挡机构设计空间受限的情况下，极大地优化了拨叉 臂载荷分配并提升了换挡拨叉的强度及耐久寿命，提出了一种提升变速器非对称型换挡拨叉 耐久鲁棒性的设计方法。

关键词: 变速器；非对称型换挡拨叉；拓扑优化；鲁棒性