Abstract: The existing FSW repair equipment was mostly fixed gantry structure, and needed rigid back support, the mobility adaptability was poor. Aiming at the problems of repairing the damaged aluminum alloy freight car bodies, a scheme of on-line repair by FSW was proposed, and a mobile non-rigid support FSW repair equipment was designed. In order to solve the problems of insufficient support and large deformation in the welding repair of non-rigid support, the rotating telescopic arm, petal type anvil plate and other structures were designed to provide enough jacking forces for welding, and the structure of petal type cutting board was optimized by finite element analysis to improve the support effectiveness. An automatic adjustment structure of milling welding radius was designed for repair welding of different sizes of damages. The non-rigid support FSW mobile repair equipment could repair 6 mm thick aluminum alloy bodies without disassembling the body plate. Practical applications show that the welding repair effectiveness is good by using non-rigid support FSW, the welding surfaces are smooth without burrs, and there are no groove tunnel defects inside. Besides, the tensile property of the weld is about 71.6% that of the base metal.

Key words: friction stir welding（FSW）, non-rigid support, mobile repair, radius automatic adjustment

摘要： 现有搅拌摩擦焊修复设备多为固定龙门式结构，且需要背部刚性支撑，移动适应性较差。针对铝合金货车车体破损修复问题，提出一种采用搅拌摩擦焊对其进行在线修补作业的方案，设计了一种移动式非刚性支撑搅拌摩擦焊修复设备。为了解决非刚性支撑焊接修复过程中支撑力不足、大变形等问题，设计了旋转伸缩臂、花瓣式砧板等结构，为焊接提供足够的顶锻力，并利用有限元分析对花瓣式砧板结构进行优化设计，改善支撑效果；设计了铣焊半径自动调整结构，用于不同大小尺寸破损的修复焊接。该移动式非刚性支撑搅拌摩擦焊修复设备能够在不拆解车体板材的情况下，修复6 mm厚铝合金车体，现场实际应用表明：采用该非刚性支撑搅拌摩擦焊修复效果良好，焊接表面光滑无飞边，内部无沟槽隧道缺陷，焊缝抗拉性能达到母材的71.6%左右。

关键词: 搅拌摩擦焊, 非刚性支撑, 移动修复, 半径自动调整