Chang et al。 [14]established a genetic algorithm to solve the problems ofranking the working steps in progressive dies。 Kim et al。[15] developed a process planning system for an electricproduct with bending and piercing operation。 Ismail et al。[16] developed an interactive feature-based strip layout design system using cheap CAD software。 Ghatrehnaby andArezoo [17] introduced a mathematical model based on settheory to optimize strip layout using a minimum number ofstations and a torque equilibrium criteria。 Tor et al。 [18]introduced a knowledge-based blackboard framework forthe stamping process planning to speed up the progressivedie design process by automating the strip layout design。Jiang et al。 [19] proposed a systematic representationscheme of insert design automation for progressive diesusing an object-oriented, feature-based approach。Giannakakis and Vosniakos [20] developed an expert system for both process planning and die design of sheet metalcutting and piercing operations。 Jia et al。 [21] developed anautomated plate hole design system for progressive dies。
Jiaet al。 [22] introduced an automated structural design ofpunches and dies for progressive dies。Though designing dies is a very knowledge-intensive,complex, and time-consuming process, technologies usedthroughout the process are mature, which makes the entireprocess routine。 To make the design process more efficientand of higher quality, this paper introduces an automatedstructural design system for progressive dies with drawing,bending, and punching operations。 Designers only need toinput a minimum set of design information and the systemwill automatically accomplish the structural design of progressive dies。2 Progressive die designThe outer shell of a mobile phone is fabricated by theprogressive stamping process。 The design of the progressive stamping consists of two parts: layout design ofthe sheet metal strip and structural design of the progressive die。2。1 Sheet metal strip layoutThe stamping process of shells for mobile phones, as shownin Fig。 1, consists of the following nine sub-tasks: the firstand second stations are for piercing the pilot holes andblanking the raw material outline。 The third station is fordrawing the shell shape。 The fourth station is for restrikingthe shell shape and piercing the pilot holes。 The fifth toeighth stations are for bending the earphone and chargerholes, blanking the keyboard and screen holes, and sidepunching the earphone and charger holes。 The last stationis for cutting products from the strip。 The progressive process includes all sub-tasks in a single die。 This die is called aprogressive die。 Each of the processes performed withinprogressive dies is called a process station。Since sheet metal strips should be fed into the progressivesystem continuously, the sheet metal coils will go though thedecoiler, straightener, and feeder before being fed into theprogressive die, where they are processed by each of theprocessing stations。 The strips not only provide raw materialsfor the stamping process but also carry workpieces from onestation to another。 The sections used to connect workpiecesfrom adjacent stations are called carriers, and the sectionsbetween carriers and workpieces are called bridges。 The distance strips move forward each time, which is called theprogressive pitch。 To correctly position workpieces in eachof the process stations, there are a number of reference holeson both carriers and workpieces, which we call pilot holes。2。2 Progressive die configurationThe design configuration of a typical progressive die, asshown in Fig。 2, consists of two categories of parts。 The firstcategory is called the main parts, which include the upper dieset, lower die set, die plate, punch plate, blank pressure plate,punch back plate, upper lifting, lower lifting, cam mechanism,blanking punch, bending punch, and dies required by eachprocess station。 The design of these parts totally depends onthe specification of the progressive dies and the requirementsof the clients。 The second category is called the standard parts,such as the socket head cap screws, dowel pins, stripper blots,guide posts, and plain guide bushings。 These standard partsare available from the market in different sizes。Progressive dies for developing shells of mobile p 级进模结构设计系统英文文献和中文翻译(2):http://www.youerw.com/fanyi/lunwen_90887.html