Effect of punch angle and punch radius on bend angle through air V-bending of sheet metal

Nowadays, the process of metal forming in the industrial of welding and machinery is developing very rapidly, especially the bending process. In the manufacturing process, bending processes are often carried out to make and repair products such as electronic panel components, automobile vehicle panels, tool-boxes, burning fish, agricultural machinery and mechanization tools, etc. The complex-shaped bend parts with high precision are increasingly needed. To achieve high precision of parts, especially the bend angle, a suitable design of process parameters is strictly considered. An experimental study was conducted to determine the effect of punch parameters (i.e. punch radius and punch angle) on the bend angle in the V-bending process. Bending tests carried out several variable variations, including the punch angle (i.e. 85°, 87.5°, and 90°), and punch radius (i.e. 1 mm, 1.5 mm and 2 mm). The angle of 85° of die is constant. The analysis of variance (ANOVA) techniques was carried out to investigate the degree of significant process parameters in the air V-bending process. The results revealed that the degree of significant process parameters in air V-bending process depended on the punch angle. It can be concluded that the punch angle is significantly affected to the bend angle (less than 90° or more than 90°) while compared to the punch radius.