CHARACTERISTICS OF MICRO INCREMENTAL IN-PLANE BENDING OF SHEET METAL USING TILTABLE PUNCH

Incremental forming methods have gained interest in recent years as a forming technique for micro and fine components. This paper presents a newly developed incremental in-plane bending with tillable punch for micro-metal sheets whose thickness is less than 1mm. The punch has two unique points. Firstly, it has a joint which enables the punch tilt freely according to the contact pressure. Secondly, the punch "sole" has a trapezoidal shape, where the toe is thin and the heel is wide. With increase of indentation, the toe bites deeper into metal than the heel resulting in the thickness distribution. As a result, the thin sheet metal is bent without any difficulty of punch positioning. Among the conditions of incremental bending, the effects of the toe angle of the punch sole during contact on the bending radius are examined by experiments, calculations and analysis. As a result, incremental forming with a tool with a toe angle of 30 degrees results in the largest sheet-metal curvature.