Sequence Planning for Bending and Shearing Operations in Progressive Dies

• Main Authors: Dean K. Sheu, 許坤定
• Other Authors: Alan C. Lin
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/00629033732424104767

博士 === 國立臺灣科技大學 === 機械工程系 === 100 === This thesis aims to study the use of a superimposition scheme to quickly plan the sequence in a progressive die design for a sheet metal part which contains bending and shearing features, and to determine the better ones among multiple feasible solutions. The major problem of applying superimposition is that the possible solutions form an excessive solution space when multiple punches are used. In order to solve the problem, this thesis introduces the following three steps: preparation of strips, punch layout, and layout evaluation. The step of punch layout uses clustering rules to classify punches into five groups: prior use (the punches must be used first), posterior use (must be used last), simultaneous use (must be used together), sequential use (certain punches must precede some others), and exclusive use (must not be used together). It then derives the compatible sets for each punch, followed by an expansion of number of punches and punch layout, in order to obtain all feasible solutions. The step of layout evaluation adopts a Multiple Criteria Decision Making (MCDM) model with a scoring function to analyze every feasible solution and determines better sequencing plans. The scoring function used is based on the following four criteria: number of stages, moment balancing, strip stability, and feeding height. In addition to proposing the methodology, this thesis also builds up a pilot system and demonstrates how the proposed method can generate feasible sequences in a strip.