アルミニウム薄板の正四角筒深絞り : ポンチ頭部潤滑と形状の相乗効果

抄録

For improving the deep-drawability of sheet metal, it is necessary to possibly heighten the fracture force of the metal on the punch shoulder. In the square shell deep-drawing, it is vital to uniformize the stress distribution along a circumferential direction at the punch shoulder, as mentioned in the previous papers. In this paper, to clarify the conditions of uniformizing the stress distribution, various lubricants are applied to the punch head, using the punches with various corner radii. In the case of the smaller corner radii, the better lubricants improve markedly the drawabiity ; but in the case of the cylindrical punch, the inferior lubricants do so only slightly. The mechanisms are explained through the measurement of metal flow and thickness strain on the punch head.