An Investigation of the Influence of Width and Thickness Reductions in Drawing Rectangular Shapes

• Main Authors: Sheng-Chi Chang, 張勝奇
• Other Authors: Heng-Sheng Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/hcfa4a

碩士 === 國立虎尾科技大學 === 機械與機電工程研究所 === 97 === Rectangular shapes are the simplified geometries of linear rails or sliders. But the theory behind drawing with rectangular shapes is more complicated with drawing with shapes of equal-lateral sides. In order to obtain minimum drawing stress or homogeneity, additional parameters such as reasonable combinations of width and thickness reductions as well as die semi-angles along the two directions have to be considered. This work starts with evaluating the influence of die semi-angle and reduction of area on drawing stress with the aid of FEM software DEFORM-3D. Redundant deformation factor was utilized to estimate workpiece’s deformation inhomogeneity. The data base was further used to verify the guideline in selecting optimum die semi-angles in drawing rectangular shapes with unequal width and thickness reductions. The corresponding redundant deformation factor was also evaluated. The results showed that some cases had good agreement with the guideline while some results fell out of the predicted range. However the error was minimal. The corresponding redundant deformation factors were well predicted with the guideline. The second part focuses on drawing with 10 and 15% reductions of area. The optimum combination of width and thickness reductions was evaluated under the condition of drawing with same die semi-angle in the width and thickness directions. The results showed that drawing stress could be reduced with less reduction in the width direction. The minimum redundant deformation factor could be obtained when the ratio of width to thickness reduction equal to the inverse of the shape’s width-to-thickness ratio.