Abstract
In this study, we produced form forming test dies and carried out press
working tests for the purpose of visualization and clarification of forming process. A
mechanism of form forming obtaining the high accuracy of shape fixation with low load was
investigated with an attention of effects of blank material properties (e.g. tensile strength) and
die cushion pressure holding a blank. The results obtained were as follows.
(1) The form forming method could be applied to the press working of steel sheets
irrespective of the tensile strength. The good accuracy of shape fixation is confirmed on the
forming of steel sheets including the tensile strength from 270MPa to 1180MPa.
(2) The press bending, which is the forming under compression load, resulted in the good
accuracy of shape fixation and lower working load on the form forming method.
(3) The optimal cushion pressure corresponding to the tensile strength of the blank sheets
must be needed in order to obtain the stable accuracy.
Keywords - Form Forming Method, High Tensile Steel Sheet, Dimensional Error,
Cushion Pressure, Press Bending