Abstract: Given the problems of insufficient sealing, low efficiency and high cost in traditional spot welding for the roof of vehicle bodies, this paper takes a certain mid-sized sport utility vehicle (SUV) model as the object and compares and analyzes the process differences and comprehensive benefits of laser brazing and traditional spot welding between the roof and the side panels. The results show that laser brazing for the roof and side panels reduces the processes of sealant application and trim strip assembly, simplifies the process flow, and increases the welding efficiency by 52%. Laser brazing forms continuous and aesthetically pleasing weld seams, significantly improving the reliability of the body-in-white performance and the flatness of the appearance. In terms of economic benefits, laser brazing reduces the weight of each vehicle by 0.67 kg and lowers the direct material cost by 49 yuan. The research indicates that laser brazing outperforms traditional spot welding in terms of process simplicity, production efficiency, light weighting, cost control, and vehicle body performance, providing theoretical support and practical reference for the upgrading of vehicle body manufacturing processes.

Key words: roof of vehicle body; laser brazing of side panels; sealant; welding efficiency; structural section

摘要： 鉴于传统点焊工艺在车身顶盖焊接中存在密封性不足、效率低及成本高等问题，文章 以某中型运动型多用途汽车（SUV）车型为对象，对比分析了顶盖与侧围激光钎焊与传统点 焊的工艺差异及综合效益。结果表明，顶盖与侧围采用激光钎焊减少了密封胶涂覆与装饰条 装配工序，简化了工艺流程，焊接效率提升了 52%。激光钎焊通过形成连续的美观焊缝，显著 提升了白车身性能的可靠性与外观平整度。在经济效益方面，激光钎焊实现了单车减重 0.67 kg， 直接材料成本降低了 49 元。研究表明，激光钎焊在工艺简捷性、生产效率、轻量化、成本控 制及车身性能等维度均优于传统点焊，为车身制造工艺升级提供了理论支持与实践参考。

关键词: 车身顶盖；侧围激光钎焊；密封胶；焊接效率；结构断面