At different forming speeds, the distribution law of equivalent stress in the forming process of each simulation experiment is basically the same. After the upper die starts moving, the part with the largest equivalent stress is mainly distributed in the part where the helical gear blank contacts the upper and lower dies. With the downward movement of the upper die, the equivalent stress in the middle part gradually increases and enters the deformation stage dominated by upsetting deformation. In this process, the equivalent stress is evenly distributed, And the value of equivalent force is relatively large; When the upsetting process is finished, it enters the deformation stage dominated by tooth formation. In this process, the metal in the tooth shape flows from the small end of the helical gear to the large end of the helical gear, and the equivalent stress at the tooth shape is large; When the metal flows to the big end, the helical gear blank basically fills the whole die cavity. At this time, it enters the stage of forming flash. Under large compressive stress, the excess metal flows to the flash groove to form flash. At this time, the equivalent pressure of the external metal of the whole helical gear blank is basically the same, and only the equivalent stress of the metal inside the helical gear blank is small. The maximum equivalent stress obtained from each group of simulation experiments at different forming speeds is 301 MPa, indicating that the distribution of equivalent stress and the size of maximum equivalent stress have no obvious relationship with the size of forming speed.
At different forming speeds, the equivalent strain distribution law in the forming process of each group of simulation experiments is basically the same. When the upper die starts to move down, the place with large strain is the tooth root of the helical gear blank. At this time, the contact position between the upper die and the helical gear blank is the tooth root of the forging. With the continuous downward movement of the upper die, the metal of the helical gear blank flows into the upper die cavity. At this time, the equal effect change at the tooth top gradually increases and even exceeds the equal effect change at the tooth root. Until the die is closed, the equal effect change at the tooth top reaches the maximum, while the equal effect change at the tooth root remains basically unchanged in the whole process. The maximum equivalent strain obtained by each group of simulation experiments at different forming speeds is different. For example, the table shows the maximum equivalent strain at different forming speeds. It can be seen from the table that when the forming speed is 12.5 mm / s, the equivalent effect becomes the smallest, which is 14.3 mm / mm.
| Forming speed (mm / s) | 5 | 7.5 | 10 | 12.5 | 15 |
| Maximum equivalent strain (mm / mm) | 17.8 | 17.0 | 15.1 | 14.3 | 15.6 |
Based on the above analysis, when the forming speed is 12.5 mm / s, the machining efficiency is high and the equal effect becomes the smallest. At this time, the forming effect is the most ideal.