变截面辊弯成形装备运动特性研究
Motion Characteristics Analysis for Variable Cross Section Roll-Forming Machine

针对U型变截面零件辊弯成形工艺要求,对变截面辊弯成形装备设计方案及其运动特性进行了研究。给出了变截面辊弯成形机的结构组成与工作原理、机构模型及其运动学方程,求解了符号形式的运动学逆解,获得了变截面辊弯成形机各个驱动轴的运动特性与末端轧辊路径的几何特性、机床结构参数以及加工速度之间的数学表达式。采用Mathematica编程对逆运动学进行仿真,获得了所有驱动轴的运动特性仿真曲线,仿真运动规律与成形工艺要求一致。基于设计方案制造了变截面辊弯成形装备,并完成了变截面辊弯成形零件的成形加工实验。实例仿真和实验结果表明:装备移动关节驱动轴的运动特性与机械结构参数、加工速度以及轧辊成形轨迹曲线有关,而转动关节驱动轴的运动特性只与轧辊运动轨迹曲线有关;新方案能够完成板材的进给、拉伸和折弯操作,实现连续的变截面辊弯成形加工,成形精度可达0.397 mm。
A scheme for variable cross section roll-forming machine is proposed and the motion characteristics are analyzed to specially meet the demand of a U？？profile variable cross section roll？？forming parts. The mechanical structure, working principle and kinematic diagram are introduced. The inverse kinematics analysis problem is solved by symbolical arithmetic, and the transformation relationship of the motion characteristics of all drive shafts to the geometrical properties of machining pat, mechanical structure parameters and velocity of feeding of the metal sheet is established. Then kinematic simulation curves of all drive shafts are obtained with software Mathematica, and the formed track well coincides with the desired shape. A variable cross section roll？？forming machine is constructed following the proposed scheme and the experiment for forming a U？？profile variable cross section roll？？forming part is conducted. The simulation and experiment show that the novel scheme enables to realize continuous process of feeding, stretching and compressing of metal sheet with the highest forming accuracy of 0.397 mm