1、J.Shanghai Jiaotong Univ.(Sci.),2010,15(3):313-318DOI:10.1007/s12204-010-1009-zA Reconfigurable Stamping Die and Its Stamping ProcessSONG Ai-ping(?),WU Wei-wei(?),ZHANG Jun(?)(College of Mechanical Engineering,Yangzhou University,Yangzhou 225009,Jiangsu,China)Shanghai Jiaotong University and Springe
2、r-Verlag Berlin Heidelberg 2010Abstract:A reconfigurable flexible poles die was developed.The die can be used to implement the process of“the multi-point pressing and forming sheet”.Sheet metal is restricted by the elastic pressing forces putting onthe upper and lower surfaces of sheet in stamping p
3、rocess.The method is an effective way to enhance the bucklingcritical stresses and reduce wrinkling of sheet.The results of tests indicate that the die can achieve“one diebrings multi-purpose”and suppress the wrinkle of sheet.The process of the multi-point pressing and formingsheet provides a practi
4、cal and effective way for the curved sheet metal forming.Key words:stamping process,wrinkle,reconfigurable,dieCLC number:TG 386Document code:A1IntroductionWrinkling of sheet metal seriously influences theforming quality and the life of die.It may make theforming process unable to carry on.So effecti
5、vely sup-pressing wrinkle seems to be highly important1.Inrecent years,in order to meet the demand of light andtough sheet metal,thin sheet metal parts are widely ap-plied in various fields.The study of Wrinkling becomesone of the hottest research topics2.Since the near century,many scholars have br
6、oughtmassive studies and discussions into the instability ofsheet.These researches covered from the experimentalstudy and the theoretical analysis to the numerical sim-ulation,from the sheet drawing and the bend formingto the hydroforming,from the wrinkle forecast to thebuckling control and so on1-3
7、.Recently,numerical simulation of a forming processis applied to study on wrinkle.Depending on the mod-ern advanced research methods,numerical simulationbased on the finite element method has become themain tool of study wrinkling in decades4.However,majority studies encircle wrinkling bifurca-tion
8、of sheet metal and the situations of wrinkling atthe present time.But these cannot bring any feasiblemethod for controlling the wrinkles in stamping.Currently,the representative research and applica-tion of the reconfigurable die technology is the multi-point forming technology.The basic principle i
9、s using aReceived date:2009-04-02Foundation item:the National Natural Science Foundationof China(No.50975249)and the Natural ScienceRe-search Fund of Yangzhou University(No.YZ2009093)E-mail:series of regular and adjustable the basic bodies(poles)to construct the structure of a die.Thus,the recon-str
10、uction of die can be achieved,but the wrinkling inthe sheet metal has not been suppressed5.The paper emphasizes how to control wrinkle of sheetforming.Main ideas in the paper are two:One ideais to improve the supporting condition of sheet metaland increase its buckling critical stresses.Thus,“themul
11、ti-point pressing and forming sheet”technique willbe proposed.Another idea is to explore a reconfigurabledie which is combining the technique of“the multi-pointpressing and forming sheet”.2Poles Flexible DieIn order to reduce the wrinkling of sheet,a method ofusing elastic pressing forces putting on
12、 surfaces of sheetin stamping process was presented,it can improve thestability of sheet metal.A new reconfigurable die was developed.The die hashigh efficiency in reconfiguration so that it can achievemulti-purpose use.Simultaneously the die can be car-ried out the process of“the multi-point pressi
13、ng andforming sheet”.Curved sheet metal parts are used in many productssuch as aerospace products,military products,shipsand engineering machines,the batch of parts is small.Different shape requires different die for forming sheetmetal.It leads to high cost and long cycle6-7.To meetthis situation,th
14、e reconfigurable stamping die has beenexplored.The die can be applied to forming a varietyof sheet parts by reconfiguring.The novel die is namedas“poles flexible die”.Poles flexible die is a kind of reconfigurable stamping314J.Shanghai Jiaotong Univ.(Sci.),2010,15(3):313-318die.Figure 1 shows the st
15、ructure.The die is com-bined with some discrete adjustable poles which areassembled in an array.The length of pole can be ad-justed.After analyzing 3D models data of sheet part,the length of each pole can be adjusted accurately8.1Frame,2Screw rod,3Adjustable sleeve,4Baffle5Jointer,6Punch head,7Blank
16、-holder,8Sheet metalFig.1The structure of poles flexible diePunch head located in the end of pole can be replacedwith relevant shape head.All heads are constituted thesurface of die so that it is conformed to the shape ofsheet part.The die is composed with flexible poles.In orderto realize the multi-point pressing and forming sheetprocess,the adjustable pole is designed as a flexiblepole with the function of“pressing sheet”and“formingsheet”.Figure 2 shows the scheme of the flexible pole.12345687
