Research On The Forging Process Of RV Reducer Output Flange And Improvement For The Die Life

The output flange is an important part of the robot's RV reducer,which is mainly used in the joint drive of the robot.The reducer is required to have high performance because the robot's working environment is complex and changeable,and it is often in the condition of multiple vibration,big impact and frequent torsion.As the core part of the RV reducer,the performance of the output flange has a direct impact on its service life.At present,the output flange is mainly formed by casting,and the parts are prone to fracture which affects the stability and safety of the reducer.Therefore,the comprehensive performance of the output flange need to be improved by forging.In this paper,a output flange as the research object,the forging process is studied at first,and then the defects of forming process are analyzed by the finite element simulation software DEFORM-3D.At last,the service life of the die can be improved through the optimization of the forging process parameters and improvement of die manufacturing process.The main research contents are as follows:Firstly,in order to solve insufficient forming of output flange in a company's first trial production,the structure of the output flange was analyzed.Based on filling with 6 small boss,a new forging process was designed which consisted of upsetting,pre-forging,finish forging and trimming.Although the forging was fully filled enough,the folding defects appeared.Secondly,the flow of the metal forming was analyzed by the finite element simulation software DEFORM-3D for the folding defect.The main reason was the unreasonable design of pre-forging.Therefore,combining with the CAE analysis,the pre-forging was redesigned.After production verification,the forging was completely and unfolded.However,there was a failure of pre-forging die in the volume production.Thirdly,the main position of the wear was obtained through the finite element analysis of the forming load and the wear of the pre-forging upper die.In order to improve the die life,process optimization was carried out.A multi-objective orthogonal test was designed and three most influential factors for the comprehensive index of die life were obtained.Then the optimal combination of process parameters was obtained by mean analysis.Finally,a new manufacturing process of die was proposed according to serious wear,thermal fatigue damage and low life of the pre-forging die of output flange.They were upsetting and drawing out for three times,isothermal spheroidizing annealing,vacuum quenching and tempering for two times,sulfonitriding surface.Production verification showed that the microstructure and mechanical properties of die under new technology can meet the requirements.Also,it was verified that the dies obtained by the new technology can effectively improve the service life of dies under the conditions of optimal forging process parameters,and the production of the output flange forgings were of good forming quality.In this research,the problem of forging process for the output flange is solved by combining the traditional experiential forging process design with the finite element simulation technology.Also,the optimization of process parameters and improvement of die manufacturing process are combined to improve the service life of die for the output flange,which provide a theoretical guidance for the manufacture of such forging die and forging process of such products.