Wrinkling is easy to occur during the thick-walled head spinning. The main influencing factors are:(1)blank size and material performance; (2)Key equipment parameters such as the shape of the rotary wheel (diameter and fillet radius), adjusting angle mandrel and the clearance of the rotary wheel, etc,; (3)Process parameters such as spinning temperature, spinning passages, track traveled by the spinning machine, degree of deformation, and points reached by the spinning machine, feed amount, feed speed, and heat treatment. These factors may be incorrectly selected. As a result, forming size control and consistency are difficult.
Especially for some heads with a small aspect ratio, since the wall thickness is much smaller than the diameter, such as instability, wrinkling and cracking are very easy to occur during spin forming. Since most of the thick-walled head spinning process parameters are still choosed by experience, on the one hand, it is difficult to choose the forming parameters. On the other hand, it also has a significant impact on product quality.
We deeply study the influence of the spinning wheel parameters on the forming process, obtained the relationship between the spinning wheel parameters and the wall thickness of the head by the finite element model analysis. By increasing the feed ratio of the rotary wheel, selecting the appropriate corner radius or the adjusting angle, it is beneficial to improve the non-stickiness and roundness of the head; Angular radius, increase the installation angle of the rotary wheel. By reducing the feed ratio of the rotary wheel, reducing corner radius and increasing the adjusting angle, it can improve the deformation of the flange, and even eliminate defects such as diameter expansion and material bulging, so that the thickness distribution of the head is more uniform.
Through experimental comparison, analyzed the effects of process parameters such as the pass curve of different trajectories, the adjusting angle, and the feed ratio on the quality of multi-pass deep-drawn spinning. The results show that: under the same conditions of other process parameters, using convex-concave arc to reciprocate the wheel track of the non-pass die-casting advancement, and the wall thickness of the obtained spinning part is the most uniform. Adjusting angle of the wheel and the feed ratio is bigger, the easier the workpiece to wrinkle.