考虑传热条件的搅拌摩擦焊主轴力控制研究

Friction stir welding spindle force control considering heat transfer conditions

针对搅拌摩擦焊接过程中的试件结构和焊缝位置变化,导致主轴力波动、焊接质量不稳定的问题,对焊缝位置改变和试件结构变化两种传热条件下的热-力关系进行研究,提出考虑传热条件变化的主轴力控制方案。采用Deform-3D软件进行搅拌摩擦焊温度场仿真,并与试验测得实际焊接温度和主轴力进行对比分析,得出靠近试件边缘的主轴力的变化趋势。引入焊接力边缘效应修正系数,基于Hammerstein结构建立考虑传热条件的搅拌摩擦焊主轴力模型,并构造广义预测控制主轴力控制器。将控制器集成到西门子840Dsl数控系统中,并在焊接设备上开展工程测试。结果表明,考虑传热条件变化的主轴力控制方案的控制效果较好,在不同传热条件下,可将实际主轴力控制在期望主轴力±5%的范围内。

In order to solve the problem of spindle force fluctuation and welding quality instability caused by the change of specimen structure and weld position in friction stir welding process,we studied the heat-force relationship under the change of weld position and specimen structure and proposed the spindle force control scheme considering the change of heat transfer condition.We used Deform-3D software was used to simulate the temperature field of friction stir welding.We compared and analyzed the actual welding temperature and spindle force measured by the test,and obtained the variation trend of spindle force near the edge of the specimen.Based on the Hammerstein structure,we established a friction stir welding spindle force model considering heat transfer conditions and a generalized predictive control spindle force controller.The controller is implemented in Siemens 840Dsl numerical control system.We carried out the engineering test on the welding equipment and the test results show that the proposed control scheme has good control effect.Under different heat transfer conditions,the actual spindle force can be controlled within 5%of the expected main shaft force.