Step-Nc Enabled Manufacturing Process Planning Of Sheet Metal Bend Parts
Sheet metal bending is a major manufacturing process to transform sheet metal blanks into complex 3D parts. It is recognized but still the state of the art in CNC sheet metal bending is still recognized as a separate and vague island of automation. Absence of suitable analytical models for blank development from 3D CAD models has given rise to vendor specific adaptive CNC press brake technologies. Traditional vendor specific CAD and ISO 6983 based CNC technologies have hindered knowledge retrieval. Raw material in the form of sheet metal is subjected to various geometrical and properties variation which makes it very difficult to plastically form blanks as per design specifications. Introduction of new contemporary family of standards like STEP and STEP-NC have enabled to specify feature based sheet metal CAD modeling. STEP & STEP-NC enabled feature based sheet metal bending methodology is presented by utilizing recent developments in the field of this contemporary family of standards. This work specifies major requirements for feature based discrete sheet metal components bending design keeping in view the directional and variable sheet metal, material properties. In order to formulate this methodology STEP(ISO 10303) and STEP-NC( ISO 14649) are used for vendor neutral feature based design along with DIN 1541 and DIN 1623 standards to accommodate the effect of variable and directional sheet metal properties variation.
Keywords - STEP , STEP-NC , CNC bending , Sheet Metal Properties Variation.