Research on Stiffness Characteristics and Load Control Method of Friction Stir Welding Robot
FANG Lijin1 , ZHANG Yue2 , XU Xiaohui3
(1. Faculty of Robot Science and Engineering, Northeastern University, Shenyang 110819, China; 2. School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China; 3. Shanghai Academy of Spaceflight Technology, Shanghai 201109, China)
Abstract:Based on the mathematical model of the force on the mixing head in friction stir welding, the static model of the mixing head was established by using Ansys Workbench. The influence of forward resistance, lateral force, axial force and torque on the strain of the mixing head is analyzed. Suitable welding methods and processes are of great help to improve the stability of robot friction stir welding, and the load control methods such as friction stir spot welding, optimizing mixing head design and welding process parameters, heat source and ultrasonic-assisted, feedback measurement and compensation friction stir welding, as well as the improvement of robot structural stiffness and accuracy are described in detail. In combination with the weak overall rigidity of industrial robot, easy to cause flutter during processing, and large internal tooth gap of joint reducer, a high rigid mechanical arm with non-clearance drive based on dual motor drive is proposed, and the stiffness characteristics of the mechanical arm are discussed.