By analyzing the metal flow, stress and strain, temperature, die load and damage of the blank in the process of forming the driving spiral bevel gear blank by various forming processes, and starting from the actual production, the following conclusions can be drawn from the analysis of the production indexes of the three production processes:
(1) When the cross wedge rolling process is used to produce the driving spiral bevel gear blank, aiming at the production mode of placing the two cone heads in the middle, by changing the side of the rolling wedge from vertical to inclined inclined plane and rounding the edge of the rolling wedge, the folding in the forming process can be greatly reduced, the metal flow in this part can be improved, the connection strength between the cone head and the shaft can be improved, and the position can be changed from a dangerous area to a safe area.
(2) In the production of cross wedge rolling vertical forging method, the pit filling in the vertical forging process is after the cone head is formed, and the pit filling needs to produce a certain flash in advance to increase the die load as a condition.
(3) The extrusion vertical forging method is completely feasible in the production of driving spiral bevel gear blank, and the formed product has high precision and good quality. The driving spiral bevel gear blank can also be formed by cold extrusion cold forging, and the product quality and precision are better, but the production efficiency is very low.
(4) Cross wedge rolling has the highest production efficiency and requires less equipment, but the dimensional error of the workpiece is large, the coaxiality is poor and the material utilization rate is low. Extrusion vertical forging process has the lowest production efficiency, requires more equipment and high cost, but the formed workpiece has the highest quality, the highest dimensional accuracy and the most regular shape.
(5) When the quality requirements of products are not very high and the demand is large, cross wedge rolling can be used for production, with the highest production efficiency and the largest capacity of the same number of equipment. When the quality requirements of products are very strict and the requirements of product accuracy and coaxiality are very strict, but the demand is small, the extrusion vertical forging method can be used for production. When there are requirements for the quality of driving spiral bevel gear blank, but it is not very harsh and the demand is large, the cross wedge rolling vertical forging process can be used for production.
(6) When extruding the stepped shaft, the die load fluctuates periodically. In each cycle, the load rises first and then decreases rapidly. This is because the formed part of the metal in the severely deformed area during extrusion will leave the main working area of the die while the unformed metal will be added into the main working area of the die. The work hardening of the deformed metal will increase the die load. Therefore, the die load curve in the extrusion process presents periodic fluctuations in different stages.