US 12,472,549 B2
Stamping method and deep-drawing die for aluminum alloy liner of large-volume hydrogen storage cylinder
Shihong Li, Chengdu (CN); Cunjiang Feng, Chengdu (CN); Hao Yi, Chengdu (CN); Qingbo Gong, Chengdu (CN); Qinling He, Chengdu (CN); Jiachao He, Chengdu (CN); Yong Tang, Chengdu (CN); and Na Qi, Chengdu (CN)
Assigned to Sinoma Science & Technology (Chengdu) Co., Ltd., Chengdu (CN)
Filed by Sinoma Science & Technology (Chengdu) Co., Ltd., Chengdu (CN)
Filed on Apr. 19, 2023, as Appl. No. 18/303,136.
Claims priority of application No. 202210972644.1 (CN), filed on Aug. 15, 2022.
Prior Publication US 2024/0051006 A1, Feb. 15, 2024
Int. Cl. B21D 22/28 (2006.01); B21D 51/16 (2006.01)
CPC B21D 22/28 (2013.01) [B21D 51/16 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for stamping aluminum alloy liners of hydrogen storage cylinders, comprising:
heating and stamping an aluminum ingot to form a cup-shaped rough blank;
turning the cup-shaped rough blank on a lathe to achieve a designed size and eliminate surface defects in the cup-shaped rough blank to yield a blank;
performing an annealing treatment on the blank to remove machining stresses and soften a microstructure of the blank; and
cold deep drawing the blank to thin and lengthen the blank into an aluminum alloy liner;
wherein the cold deep drawing comprises a single pass or multiple passes;
when the cold deep drawing comprises the single pass, a thinning rate is controlled between 0.5 and 0.6;
when the cold deep drawing comprises the multiple passes, the thinning rate for a first pass of the multiple passes is controlled between 0.5 and 0.6, intermediate passes of the multiple passes are controlled between 0.63 and 0.72, and a final pass of the multiple passes exceeds 0.75.