2013 Volume 54 Issue 629 Pages 542-546
A numerical control (NC) servo press can be set to function with a variable motion in a single operation. In this study, we investigated the drawability of a cup formed by an NC servo press by measuring both sheet thickness and limiting drawing ratio. We also developed and built a new TZP test capable of evaluating NC servo press slide motion within a short time. The testing apparatus includes a sheet clamp with an NC die cushion, which eliminates the need for a dedicated die or a testing machine. As a result, the drawability evaluation with the NC servo press based on sheet thickness differed from that based on limiting drawing ratio. The proposed TZP test showed a similar trend to that of the sheet thickness evaluation. The evaluation based on the TZP test also revealed that a drawability higher than that attainable by link motion can be attained by detaching the die surfaces from the sheet at the proper position.
