Comparative Analysis And Research Of RR, TR And NTR Upset-Bending Processes For Heavy Crankshaft Of Continuous Grain Flow

Heavy crankshafts are key parts of diesel engines. Now there are two methods for producing heavy crankshafts. Obviously the crankshafts formed by upset bending are superior to that by free forging because the continuous grain flow upset bending processes improve significantly the fatigue, material usage and machining productivity. The RR and TR upset-bending forging process have been extensively used in making heavy crankshaft at home and abroad. But some inherent problems can not be solved in the forming process of crankshaft. They can not be optimized according to filling because of the limitation of the process characteristics. The NTR process is an innovation of the TR process. In NTR , upsetting and bending are decoupled by an independent additional cylinder. By optimizing the bending speed-stroke parameters, it is possible to acquire optimum crankshaft profiles to near net shape forming. In this paper, introduce RR,TR and NTR upset bending processes for heavy crankshaft of continuous grain flow and get a lot of information of every field by analyzing and researching them. Take 601 crankshaft as a example, the upset bending processes of RR,TR and NTR are numerically simulated based rigid-plastic FE . On the ground of simulations, lower bending speed at the beginning and higher speed at the ending benefit filling.