OPERATION SEQUENCING FOR SHEET METAL PARTS

Abstract

Sheet metal pressworking operations have a long past history. With technological advancements, pressworking operations have also achieved large scale automation. In order to incorporate flexibilities and reduce change over time in the present era of small batch production of complex components, CAPP was introduced in pressworking operations. In the present work, a methodology for generation of operation sequences has been proposed. It involves selection of operation steps by which the features can be produced on the part without violating the relevant technological constraints. A single sequence of operations may not be appropriate for all situations in a changing production environment, with multiple objectives such as maximizing machine utilization and minimizing number of tool changes. Keeping this in mind, a methodology has been developed for generating feasible operation sequences, satisfying the tolerance and dimensional criteria, for pressworking operations on mild steel sheet components. An interactive computer program in `C' language has been written to generate operation sequences for components containing upto 7 different group of features. These operation sequences are evaluated for the number of tool setup changes and machine changes required and the total time needed for producing a part. Functioning of the software has been ascertained by case studies. Recommendations for future work have also been made on the basis of the present work.