卧式双机联合自动钻铆系统综合刚度研究

Investigation on general stiffness of automatic horizontal dualmachine cooperative drilling and riveting system

为分析卧式双机联合自动钻铆系统中多轴机床的刚度特性分布规律,定量分析该机床末端弹性变形.建立多轴机床的运动学模型,确定运动关节、柔性运动轴和末端执行器为其末端变形主要来源;针对柔性运动轴与末端执行器的力学特性,采用有限元法得到其对应坐标系内的刚度矩阵;针对运动关节,采用试验法得到关节空间内的刚度矩阵;通过雅克比矩阵法建立运动关节的增强型末端刚度矩阵,通过点传递法建立柔性运动轴的末端刚度矩阵;基于弹性小变形理论,综合各个变形来源的末端刚度矩阵建立多轴机床的综合末端刚度模型;通过实际测试,该刚度模型与实验结果误差小于10%,证明了该综合刚度模型的准确性.

The quantitative analysis of the end elastic deformation was realized in order to analyze the distribution of stiffness performance of the multi-axis machine tool in automatic horizontal dual-machine cooperative drilling and riveting system. The kinematic model of the multi-axis machine tool was established. Machine joints, end effector and flexible links were determined to be the main sources of the end deformation in the multi-axis machine tool. Stiffness matrixes of flexible links and end effector in their respective coordinate systems were obtained by the finite element method based on their mechanical properties. The stiffness matrix of machine joints in the joint space was obtained by the test method. The enhanced end stiffness matrix of machine joints was established by the Jacobian matrix method, and the end stiffness matrixes of flexible links were established by the point transformation method. Based on the small elastic deformation theory, the end stiffness matrixes of all end deformation sources were integrated to establish the general end stiffness model of the multi-axis machine tool. Through the actual test, the error between the general end stiffness model and the experimental results was less than 10%, which proves the accuracy of the general stiffness model.