Research On Robotic Milling Process For Surface Defect Layer Of Additive Manufacturing Parts

In recent years,wire arc additive manufacturing has achieved full development,and it has a large number of applications in shipbuilding,aerospace,automobile manufacturing and other fields.With the development of domestic and foreign manufacturing industry,the requirements for additive manufacturing parts are becoming higher and higher.However,it is difficult to ensure that the size and surface roughness of forming parts can meet the requirements of arc additive manufacturing technology,which limits its application and development.In this paper,a milling robot is used to remove the defect layer on the outer surface of arc additive manufacturing parts in order to improve the surface quality of parts.The main research work of this paper is as follows:(1)Analyze the defects on the surface of additive manufacturing parts,determine the processing requirements of the parts,formulate the processing scheme for removing the defect layer,according to the existing cutting equipment,select the cutting tool and tool handle and establish the robot milling system,determine and the range of processing parameters preliminarily.(2)In order to obtain the robot milling processing path,use offline programming,write the RAPID program for the processing requirements,ensure the program feasibility through trajectory simulation,joint axis configuration and collision detection,get a variety of milling processing paths for different tools,the RAPID program can be used for machining after importing in the robot controller.(3)In order to make the robot in the optimal working state in the milling process to improve the milling efficiency,establish the milling force model and check the milling power,calculate the forces and torques acting on the end of the robot by different milling forces,establish milling robot dynamics model by using the Newton-Euler equation,the change of joint torque with time under different paths was solved by inverse dynamics,determine the milling path that has the least impact on robot joint torque,finally,in order to avoid resonance phenomenon in the milling process,the natural frequency of the milling robot is obtained by modal analysis.(4)To obtain the optimal process parameters of robot milling under different processing paths,aiming at analyzing the spindle speed,feed per tooth,cutting depth and cutting width,four parameters,single factor experiment and orthogonal experiment are carried out,to explore the comprehensive influence of different process parameters on the surface quality of parts,therefore,determine the process parameter combination of optimal surface quality after removing the defect layer with different cutting tools under different processing paths.In this paper,the processing path and process parameters for removing the surface defect layer of additive manufacturing parts by using milling robot are determined,which have important theoretical significance and practical application value for improving the surface finish and forming quality of additive manufacturing parts.