The speed of forming speed has a very important impact on the processing efficiency and quality of forgings. With the change of the down moving speed of the upper die, the load on the blank of spiral bevel gear will also change. As shown in the figure, the stroke load curve under different forming speeds is shown, in which figure (a) is the stroke load curve with forming speed of 5 mm / s and figure (b) is the stroke load curve with forming speed of 7.5 mm / s, Figure (c) shows the stroke load curve with forming speed of 10 mm / s, figure (d) shows the stroke load curve with forming speed of 12.5 mm / s, and figure (E) shows the stroke load curve with forming speed of 15 mm / s. It can be seen from figure 3.12 that the variation law of stroke load curve is basically the same under different forming speeds. When the forming speed is 5 mm / s and 7.5 mm / s, the initial load changes slowly with the stroke. At this time, the load is very small. When the stroke gradually increases to about 7.2 mm, the load increases rapidly. When the forming speed is greater than 10 mm / s, the above process will not occur. At this time, there is a linear relationship between the load and the stroke. For the stroke load curve of different forming speeds, when the stroke reaches about 16mm, the load will suddenly increase and enter the forming process of tooth profile until the load reaches the maximum when closing the die.
(b) Stroke load curve with forming speed of 7.5 mm / S
(d) Stroke load curve with forming speed of 12.5 mm / S
The table shows the maximum load under different forming speeds. It can be seen from the table that there is little relationship between the maximum load and the forming speed, but the slower the forming speed is, the longer the contact time between the die and the high-temperature spiral bevel gear blank is, which is easy to make the die fail due to thermal fatigue. Moreover, the higher the forming speed is, the processing time can be saved and the processing efficiency can be improved.
| Forming speed (mm / s) | 5 | 7.5 | 10 | 12.5 | 15 |
| Maximum load (KN) | 5380 | 5400 | 5400 | 5400 | 5420 |