Abstract: In order to improve the assembly accuracy between the power battery assembly and the vehicle body, the paper takes the size deviation of the power battery mounting hole on the body of the new energy car as the analysis goal. The local installation datum is established and the error accumulation at different levels of welding by using the two-dimensional dimension chain is analyzed. The design idea of the Geometry Dimensioning & Tolerancing (GD&T) of the battery mounting hole is introduced in detail, verified with the help of the three-dimensional deviation analysis software 3DCS, the installation accuracy of new energy vehicle battery is ensured. Besides, the risk of on-site assembly is reduced and the assembly efficiency is improved. It has accumulated experience for the geometric tolerance design of key hole locations in the drawing stage of subsequent projects.

Key words: Power battery; Assembly accuracy; GD&T; Deviation analysis; 3DCS; Vehicle body

摘要： 为提高动力电池总成与车身匹配精度，文章以新能源轿车车身动力电池安装孔尺寸偏 差为分析目标，从建立局部安装基准，到运用二维尺寸链分析焊接不同层级误差累积，详细 介绍了电池安装孔的几何尺寸和公差（GD&T）设计思路，并借助三维偏差分析软件 3DCS 进行验证，保证了新能源汽车电池的安装精度，降低现场装配风险的同时提高装配效率。为 后续项目在图纸阶段对关键孔位几何公差设计积累了经验。

关键词: 动力电池；装配精度；GD&T；偏差分析；3DCS；轿车车身