基于多轴刀路轨迹的自由曲面磁粒研磨试验  

Test on Magnetic Abrasive Finishing of Free-form Surface Based on Multi-axis Tool Path Trajectory

作　　者：赵耀耀 陈松[1] 李昌龙 李鑫[1] 李雨龙 ZHAO Yao-yao;CHEN Song;LI Chang-long;LI Xin;LI Yu-long(School of Mechanical Engineering&Automation,University of Science and Technology Liaoning,Liaoning Anshan 114051,China)

机构地区：[1]辽宁科技大学机械工程与自动化学院,辽宁鞍山114051

出　　处：《表面技术》2023年第4期319-328,共10页Surface Technology

基　　金：国家自然科学基金(51775258);辽宁省教育厅项目(2020FWDF07);辽宁省教育厅项目(2020FWDF05);辽宁科技大学基金(2018FW05)。

摘　　要：目的通过自由曲面的磁粒研磨试验,使工件曲面经研磨后能够获得较好的表面形貌,降低工件的表面粗糙度。方法使用UG生成曲面三维模型,利用后处理功能,生成包含刀具位置和姿态的刀位文件,提取刀位文件中原始的刀路轨迹点,分析刀路轨迹,利用曲率的临界值提取轨迹的特征点。采用积累弦长参数化法对提取的轨迹特征点进行三次B样条插值,对比插值前后轨迹点拟合曲线在z轴的误差,再根据刀轴矢量计算机械臂末端姿态。选择磁极的不同开槽方式,并在Ansoft Maxwell软件里进行仿真模拟和分析,选定理论上较优的球形开槽磁极形式。通过试验加工铝合金自由曲面,对比研磨前后的表面形貌和表面粗糙度。结果使用积累弦长参数法进行3次B样条插值,获得了步长较为均匀的轨迹点,优化了原始刀位轨迹。在球形磁极上进行开槽,使均匀磁场变为非均匀磁场,同时使最大磁感应强度由0.556 T增至0.727 T,增大了磁粒研磨过程中的研磨力。对铝合金曲面的部分区域进行60 min的研磨,其表面平均粗糙度从原始的Ra 8.71μm降至Ra 0.56μm。结论将磁粒研磨与六自由度机械臂结合,进行曲面的光整加工,可以有效改善工件的表面质量,降低其表面粗糙度。The work aims to obtain a better surface morphology and reduce the surface roughness of the workpiece through the magnetic abrasive finishing test of the free-form surface.UG was used to generate 3D surface model,and the processing module was entered after setting of the tool type,machining allowance and other pre-processing.The post-processing function was adopted to confirm the tool path,and obtain the standard tool position file including the tool position and attitude.The original path point of the tool was obtained after removal of the machining G code.The curvature value was obtained through the approximate solution of the three-point method,the mean value of curvature was set as the threshold for distinguishing feature points from non-feature points and the feature points from the original trajectory were drawn with the critical value of curvature.Cubic B-spline interpolation was performed on the feature points by the accumulated chord length parameterization.The corresponding coordinate values were extracted from the digital module and compared with the original point and the interpolation point,thus analyzing the error of the curve fitted in the z axis.Then,the posture of the end of the manipulator was calculated according to the tool axis vector.The different slot methods of magnetic pole were simulated and analyzed in Ansoft Maxwell software,and the better spherical slot magnetic pole form in theory was selected to increase the lapping force.The surface topography and surface roughness of aluminum alloy before and after grinding were compared through tests.By accumulating chord length parameter method for cubic B-spline interpolation,the trajectory points with uniform step length were obtained,and the initial tool path was optimized.To a certain extent,the disadvantage of the large difference in the stroke of the end effector at the same time was improved.Slotted was carried out on the spherical magnetic pole to change the uniform magnetic field into a non-uniform magnetic field,and at the same time,ma

关 键 词：磁粒研磨 表面光整加工 自由曲面 六轴机械臂 三次B样条插值 

分 类 号：TG580.68[金属学及工艺—金属切削加工及机床]