New mathematical approach for automatic piloting in computer aided progressive die design

Abstract

Nowadays, progressive dies have a special role in various methods of sheet metal production. The design process, however, requires a considerable amount of time and expertise. During the last three decades, different concepts of computer aided progressive die design (CAPDD) have been studied all around the world. CAPDD includes various activities and among them piloting has been paid the least attention by researchers. In this paper, a mathematical model, based on the medial axis transform is introduced. This model analyses the part geometry in order to determine the piloting system. The model optimizes the piloting system using a minimum scrap strategy and other technical considerations. A program is also developed to automatically select the most suitable existing holes or design auxiliary holes on the scrap part of the strip for piloting purposes. The input to the program is the nesting template of the workpiece, which is composed of line and arc segments, and the output is the piloting system. The model is demonstrated through several industrial examples.

A system for computer-aided gating design for multi-cavity die-casting dies

“…The developed system blends the die-casting die-design rules and the industry best practices, along with the flexibility desired by a die-designer in a CAD system environment, and proves to be an effective tool in the hands of a die-designer. Development of systems for die-design for various near net-shape processes 23–31 brings the advantages of lower lead time besides reducing the effort of the die-designers. The developed system significantly reduces the time required for the design of gating system, needs little user interaction, and is very much useful for the industry.…”

Development of a method to recognize punch shapes for progressive dies

“…In a CAD environment, however, it is more convenient and straightforward to use the CAD parameters for shape representation. When model-matching technique 18,19 is considered, this work has given a precise representation of the shape for piecewise smooth simple closed curves consisting of line and arc segments. That is, the bulge factor, linear dimension, and rotational angle between segments form the shape component for the representation of the shape of a contour.…”

“…Cheok et al 15 also proposed the skeleton retrieving method to determine the punch shape; the system is made based on the medial-axis technique. Similar to Cheok et al, 15 Ghatrehnaby and Arezoo [16][17][18][19] also used the medial-axis technique to retrieve punch shapes in case of progressive dies. Ismail and colleagues [20][21][22] proposed a mathematical technique based on vector-to-vector coding.…”