基于焊点压痕的伺服焊枪点焊质量在线检测方法

On-line weld quality inspection based on weld indentation by using servo gun

针对目前车身点焊质量检测广泛采用的破坏性检验和无损检测方法中存在离线、小样本、检测成本高的缺点,借助于伺服焊枪编码器的位移反馈特性提出一种基于压痕的焊点质量在线检测方法。试验建立包括机器人及控制器、伺服焊枪和焊接控制器在内的点焊试验系统,利用伺服焊枪编码器位置反馈特性在线获取焊点压痕,通过PLC位移采集系统在线标定压痕获取精度,最后以0.8mm的普通低碳钢板(GMW2)为例,完成基于压痕的焊点质量在线评价。试验结果证明,伺服焊枪编码器位置反馈精度能够满足焊点压痕测量要求,点焊接头质量在线评价的准确率符合实际生产要求,文中提出的基于压痕的点焊质量在线评价方法可以实现点焊接头的在线检测。

Resistance spot welding (RSW) is the primary joining method for car-body assembly.Control and inspection of weld quality have great importance to improve the performance of car.Based on the position feedback characteristics of servo encoder, on-line weld quality inspection method was proposed by using weld indentation.A spot welding experimental system including robot, robot controller, servo gun and weld controller was integrated.The developed measurement program was used to acquie weld indentation on-line, and the measured results was calibrated by PLC displacement control system.The experimental results showed that the acquired weld indentation can reflect the real indentation on the 0.8mm low carbon steel(GMW2). The weld quality inspection rate can meet the demand for real production. The proposed on-line weld quality inspection method can meet the demand of welded joint measurement in real plant environment.