Simulation And Experimental Study On The Roll Forging Process Of 16-Type Of Coupler Yoke

Coupler yoke is an important connecting part of freight train, with the increase of demand of railway transportation, more attention has been paid to heavy load and speed of freight truck. As an important part of the buffer device, the performance requirement of coupler yoke is also increasing, so the development and research of its forming process is particularly important. Forming process of coupler yoke has mainly experienced two stages: casting and forging process.At present, roll forging is mainly forming process.With the development of processing, the manufacture becomes more and more automatic and intelligent. Roll forging process is easy to realize automation, high efficiency, saving metal material and improving the immanent quality of forgings and good working conditions, and be utilized more and more widely, especially for blocking or forming of long axial forgings. The 16-type coupler yoke studied in this paper was manufactured by roll forging and integral die forging technology.It was conducted thoroughly that theoretical study and experimental verification in this paper. mainly include analyzing the deformation laws of roll forging forming, optimizing the process, die designing, the application and the optimizing buckling groove structure in the roll forging die.With the rapid development of computer,the finite element simulation technology in forging forming process has been widely used and developed, it is also very important of optimization of mold design and forging quality control.Based on the Qform 3D simulation software, the four stock of each roll forging process are obtained, which includes the deformation, the shape size, the temperature field, the stress field, the strain field and also on.Through the analysis of the simulation results, the parameters of roll forging die were optimized, the defects of roll forging process mechanism were obtained, the solutions to solve the defects were proposed.In roll forging deformation process, the length of the roll forging was affected by the billet temperature and the clearance between the roll forging die, the range of the clearances is 1mm~6mm, the range of billet temperatures is 1175℃ ~1250℃. The parameters were divided into multiple groups for simulation analysis, the relationship of the length of forgings and forging die gap, initial billet temperature of the 16-type coupler yoke was obtained.By the line tracing method, the paper analyzed the reason of instability phenomena occurred in the 16-type coupler yoke’s roll forging process, put forward the structure of anti- instability groove for the instability phenomenon and optimized the roll forging die by orthogonal experiment. By adding the structure of anti-instability groove in roll forging die, this method not only improved the quality of roll forging for the die forging process, but also played an important role in reducing the forging load and the die wear.The results show that: provided a reference for the subsequent roll forging process design on the 1250 mm roll forging machine by the numerical simulation analysis and optimization parameter of roll forging die design. In view of the instability phenomenon of the 16-type coupler yoke roll forging process, the structure of anti- instability groove was put forward for the first time, the effect of the structure on solving the instability was obvious and also can be extended to other long arc roll forging die’s design.