The Numerical Simulation And Process Optimization Of The Bevel Gear Forging

Bevel gear is an important part for movement transmission and direction change of mechanical equipment.It is subjected to continuously torsional load in the process of movement transmission,so it has higher requirements on the precision and mechanic performance.Since 2011,the demands of gear has been increasing sharply in china,small-diameter gears using precision forging,however,if large-diameter gear is formed by mold forging which leads to low mold life,need high forming load,complex processes,so the number of large-diameter gear still produced by the turning process in some plants,which leads to long production cycle gears,low blank utilization and poor mechanical properties.It’s extremely urgent to research a new process to produce the large-diameter bevel gear by forging.The bevel gear material is DIN-15CrNi6 and the D_max of the bevel gear is 156 mm.According to the forging process:when the diameter is beyond 100mm or more,then combine hot forging steps with cold finishing to produce the gear.Based on numerical simulation,to ensure the accuracy of the gear tooth,the load reaches 55000KN in the final hot forging step by the traditional process,so it has high requirement in mechine.In this paper,introduce the flash groove into mold design in order to reduce the forging load.Based on the analysis of the initial wear pattern of the bevel gear preforming,the optimization design of the bevel gear hot forging1 mold and hot forging2 mold was carried out by taguchi robust design.The scheme was modeled and simulated by UG and Deform.Wear depth and forming load as the target of analysis,then analysis target by S/Rand determine the best process.The prediction formula is used to predict the target and compare it with the S/R analysis.The variance analysis method is used to calculate the significance of each design parameters and verify the accuracy of experiments by the taguchi robust design.Based on the response surface method to optimize hot forging1 and hot forging2forming parameters,and the experimental scheme was simulated by Deform.The mold wear,forming load and the temperature as the response target of hot forging1.The response targets of the hot forging2 are mold wear depth and forming load.The response surface method was used to fit the response target,and the predicted value and the actual value was fitted well.Variance analysis was performed on each response target,and the significance of the model was judged according to the value.Through the response surface analysis of the target and the response surface to respond to the target prediction,to determine the best combination of design variables.Using Deform software to verify the optimized scheme and analysis the wear depth,forming load,mold-stress and so on.The accuracy of experimental design is determined and the bevel gear is obtained by the practical production of the bevel gear.