Multi-objective optimization design of the cam linkage mechanism of the automatic welding device

SONG Zhicheng; YU Feng; DENG Yuanchao; CAI Yufei

doi:10.16578/j.issn.1004.2539.2025.02.010

Abstract：[Objective]To improve the automation welding production efficiency of steel columns and rib plates,a special welding torch moving mechanism has been designed.[Methods]Firstly,a cam linkage combination mechanism was designed to meet the moving trajectory and speed of the welding gun.Then a kinematic model of the mechanism was established.Secondly,based on the NSGA-Ⅱ algorithm,taking the transmission performance of the mechanism and the overall size of the mechanism as the optimization goals,a multi-objective optimization design of the connecting rod length was carried out under limited condi-tions,and the entropy weight method was used to select the optimal connecting rod length from the Pareto non-inferior solution set.Thirdly,the optimal roller coordinates were searched in the two-dimensional plane with the optimal rod length,and Matlab programming was used to obtain the convex contour line to verify that the cam pressure angle meets the design requirements.Fi-nally,based on the optimization results and combined with actual working conditions,the mechanism was modeled,and the Ad-ams simulation was used to obtain the working trajectory,speed and acceleration of the mechanism.[Results]The results show that the mechanism can meet the design requirements of welding trajectory and uniform speed welding as scheduled.At the same time,the optimized cam base circle radius is reduced by 29.79%compared with before optimization,and the speed and ac-celeration fluctuations are smaller.The correctness of the mechanism and the feasibility of the method are verified,and it pro-vides a reference design method for the design of other cam linkage mechanisms.