厚板窄间隙多层多道自动化激光填丝焊接及焊缝跟踪

发布时间：2018-05-01 17:29

本文选题：激光填丝焊 + 多层多道规划　；参考：《上海交通大学》2015年硕士论文

【摘要】：传统上,窄间隙激光填丝焊主要以人工示教为主,人为因素对焊接质量影响较大,焊接效率低。针对以上问题提出厚板窄间隙多层多道自动化激光填丝焊接及焊缝跟踪。首先研究了厚板激光填丝焊的工艺参数。实验结果表明,影响填丝焊焊缝成型的主要因素有激光功率、送丝速度、焊接速度、离焦量以及保护气流量。随激光功率的增加,单道焊缝的填充量下降,熔宽增加;随着送丝速度增大,焊缝填充量与堆高均增大;焊接速度的增加导致焊缝填充量与堆高下降,熔宽因热输入减小而下降;离焦量对熔深的影响较大,随着离焦量增大,焊缝熔深下降;保护气体流量过大,会影响焊缝成型的质量。其次建立单道填丝焊的焊缝几何与焊接输入参数之间的关系。本文通过响应曲面法分别建立了焊缝填充横截面积、熔宽、堆高、熔宽与堆高的比值与激光功率、送丝速度以及焊接速度之间的数学关系。验证实验结果表明,所建立的模型均能准确的对焊缝的几何参数进行预测。继而建立了基于单道填充横截面积的多层多道焊缝轨迹规划方法,包括焊接道数、焊枪端点坐标的算法、填充顺序等,使得焊道规划更加准确。随后利用KUKA机器人编程实现多道焊焊接程序。最后结合焊缝跟踪传感器实现了多层多道焊缝跟踪。该激光扫描式传感器能够实时调整焊缝跟踪轨迹,避免焊接过程中因焊接变形或者工装移位导致焊枪端点偏离原焊接轨迹的问题。验证实验结果表明,采用上述方法,能够准确的对焊缝几何、焊接道数、焊枪端点坐标偏移量进行预测。对于多层多道焊接接头缺陷的分析表明,热输入P/Vw以及送丝速度与焊接速度的比值Vf/Vw是影响接头质量的主要因素。另外,单道焊缝熔宽Ww与被填充层宽度Wt的比值会影响多层-单道填充时缺陷的形成。
[Abstract]:Traditionally, narrow gap laser wire filling welding is mainly manual teaching, and human factors have great influence on welding quality and low welding efficiency. Aiming at the above problems, a multi-layer multi-channel automatic laser wire filling welding and seam tracking for thick plate with narrow gap is proposed. The technological parameters of thick plate laser wire filling welding are studied. The experimental results show that the main factors affecting the weld formation are laser power, wire feeding speed, welding speed, defocusing amount and protective gas flow rate. With the increase of laser power, the filling amount of single-pass weld decreases and the weld width increases; with the increase of wire feeding speed, the filling amount and stack height of weld increase; the increase of welding speed results in the decrease of weld filling and pile height. The width of weld decreases because of the decrease of heat input, the influence of defocusing on weld penetration is greater, and the weld penetration decreases with the increase of defocusing, and the quality of weld formation is affected if the flux of protective gas is too large. Secondly, the relationship between weld geometry and welding input parameters is established. In this paper, the mathematical relations between the cross section area, weld width, stack height, the ratio of weld width to stack height and laser power, wire feeding speed and welding speed are established by the response surface method. The experimental results show that the established models can accurately predict the geometric parameters of the weld. Then, a multi-layer and multi-pass weld trajectory planning method based on single-pass cross-sectional area is established, including the number of welding passes, the algorithm of torch endpoint coordinates, filling sequence and so on, which makes the welding path planning more accurate. Then the KUKA robot is used to realize the multi-pass welding program. Finally, multi-layer and multi-track seam tracking is realized with weld tracking sensor. The laser scanning sensor can adjust the track track of welding seam in real time, and avoid the problem that welding torch ends deviate from the original welding track due to welding deformation or tooling shift during welding process. The experimental results show that the above method can accurately predict the weld geometry, the number of weld passes and the offset of welding torch endpoint coordinates. The analysis of defects in multi-layer and multi-pass welded joints shows that the heat input P/Vw and the ratio of wire feeding speed to welding speed Vf/Vw are the main factors affecting the joint quality. In addition, the ratio of weld width W _ w to W _ t will affect the formation of defects during multi-layer and single-pass filling.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG409

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