Abstract
In order to adapt to small-lot production of hole-flanged components, a process of rotary burring in which a blank is formed to fit on a tool-envelope surface made by relative motion of a tool around the blank, was proposed. Aluminum blanks were rotary-formed to hole-flanged components with various hole-diameters by means of the proposed burring operation, and the deformation behavior was examined experimentally. It is found that, by using a cylindrical tool with shoulder, the excess bending in the large clearance zone between the blank holder and the tool-envelope surface decreases with increasing of hole expanding ratio, so that the blank fits well with the tool-envelope surface. This result suggests that the proposed rotary burring method is suitable to adapt to small-lot production of the hole-flanged components. Furthermore, experimental results show that the values of the flange height agree well with those obtained by the uniform thickness model; the flange height is little affected by several conditions such as tool feed, work-hardening exponent and lubrication.
