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朽木易折，金石可镂。千里之行，始于足下。第页/共页Theconceptoftheplasticforming(Sheetmetalforming)塑性成形（金属板料成型）概念：sheetmetalformingarethosewhichforceappliedtoapieceofsheetmetaltomodifyitsgeometryratherthanremoveanymaterial.Theappliedforcestressesmetalbeyonditsyieldstrength,causingthematerialtoplasticallydeform,butnottofail.Bydoingso,thesheetcanbebentorstretchedintoavarietyofcomplexshapes.Sheetmetalformingprocessesincludethefollowing板料成型工艺是在外力作用下改变金属板料的几何形状而不是去除任何材料。施加在金属上的外力取决于其屈服强度，使其产生塑性变形但不是失效。通过这种主意，金属板料可以被弯曲或者拉伸成为各种复杂的形状。金属板料成型工艺包括以下：Bending弯曲成型1.concept概念：Aforceisappliedtoapieceofsheetmetal,causingittobendatanangleandformthedesiredshape.Thebendingoperationcausesdeformationalongoneaxis,butasequenceofseveraldifferentoperationscanbeperformedtocreateacomplexpart.Bentpartscanbequitesmall,orupto20feetinlength.Abendcanbecharacterizedbyseveraldifferentparameters弯曲成形是一个外力作用在一个金属板上，引起了一个角度的弯曲而得到我们所需要的形状。弯曲变形会引起沿着一个弯曲轴的变形，但是一系列不同的操作会产生一个复杂的部分。弯曲部分可能会异常小，也有可能会达到20英尺那么长。弯曲可以通过一些参数来表示:弯曲线bendline模外线outsidemoldline法兰长flangelength模线距moldlinedistance弯曲轴bendaxis弯曲宽bendlength弯曲半径bendradius弯曲角bendangle弯曲斜角bevelangle中性层neutralaxissetback弯曲余量bendallowance暗示图：中性层neutralaxis：thelocationinthesheetthatisneitherstretchednorcompressedandremainsataconstantlength;outsideoftheneutralaxisundergothetensionandbecomelanger;insideportionexperiencedcompressionandbecomeshorter中性层处不受力长度不发生变化，中性层上方受拉应力并且变长，中性层下方受压应力并且变短.暗示图：Springback回弹：whichiscausedbyresidualstresses,duetoelasticrecovery.Theresultsofthespringbackisgreaterthebendradiusandsmallerthebendangle.Theamountofthespringbackdependsonseveralfactorsincludingthematerial,thebendoperation,theinitialbendangleandbendradius.回弹是因为残余应力导致的，是因为弹性回复。回弹导致了弯曲半径变大，弯曲角变小。回弹量的大小主要是由材料本身，弯曲主意，弯曲半径和弯曲角度等一些因素决定的。暗示图：Componentsofthepressbrake压力机组成：punch凸模，die凹模，backgauge后靠规，hydraulicram液动压头，bed床身。TwokindsofbendinginV-bending两种不同的V形弯曲的主意（1）airbending空气弯（2）bottoming底部弯暗示图：Wipebending（oredgebending角弯）暗示图：Designrules：eq\o\ac(○,1)bendlocation弯曲位置：abendmustlocatedwhereenoughmaterialispresent,andpreferablewithstraightedge.Thewidthofthisflangeshouldbeequaltoatleast4timesthesheetthicknessplusthebendradius.弯曲必须位于有充足的材料除处并且必须位于较好的直边处。法兰宽度必须大于板厚与弯曲半径之和的四倍。eq\o\ac(○,2)bendradius弯曲半径：useasinglebendradiusforallbendstoeliminateadditionaltoolingsandsetups所有弯曲都使用相同的弯曲半径便于简化模具结构。eq\o\ac(○,3)holesandslotstooclosetoabendmaybedistorted.Thedistanceofsuchfeaturesfromthebendshouldbeequaltoatleast3timesthesheetthicknessplusthebendingradius孔，缝等要素不能太临近于弯曲，可能发生畸变。这些要素距离弯曲处的距离必须在板厚与弯曲半径之和的三倍以上。Rollforming轧辊成型ActuallyRollformingisametalformingprocessthatshapedthroughaseriesofbendingoperations.Thesheetmetalstockisfedthroughaseriesofrollstations.Eachstationhasarollerandalsotherehavearollerdiepositionedonbothsidesofthesheet.Whenthesheetforcedintothestation,itdeformsandbends.Andtherollerdiearelubricatedtoreducefrictionbetweenthedieandthesheet,thusreducingthetoolwear.Also,lubricantcanallowforahigherproductionrate,whichalsodependsonthethicknessofthesheetandthenumberofrollerstationandalsotheradiusofeachbend.实际上，轧辊成型是板料通过一系列的弯曲之后成型的主意。板料被送入一系列的滚压工序中，每一个工序都有一个辊子和有一个辊模，它们在板料的两边起成型和定位作用。当板料没送入工序时，它发生弯曲变形。为了减小模具和板料之间的摩擦力，在辊模上使用润滑，因此也减小了工具的磨损。同时润滑剂还可以在一定的条件下产生一个更高的生产率。固然，生产率主要是按照板料的厚度，滚压的工序数量，以及弯曲半径所决定的。暗示图：Example:theoutlineofthephotoframe像框的边框图：Deepdrawing拉深Atoolpushesdownwardonthesheetmetal,forcingitintoadiecavityintheshapeofthedesiredpart.Deepdrawingismosteffectivewithductilemetals,suchasaluminum,brass,copper,andmildsteel.Theformshapeincludedtanks,cups,cans,pots,andpans.Thedeepdrawingsystemaremadeofseveralpartsincludingtheblank,blankholder,punch,die.Theblankisclampedbytheblankholderoverthedie,whichhasacavityinexternalshapeofthepart.Atoolcalledpunchmovesdownwardintotheblankanddraws,orstretches,thematerialintothediecavity.Andafterapartiscompletelydrawn,thepunchandblankholdercanberaisedandthepartremovedfromthedie.Theportionofthesheetmetalthatwasclampedundertheblankholdermayformaflangearoundthepartthecanbetrimmedoff.Becauseofthewearwhichisfromtheforcesappliedtothesheetmetalandwhereisbetweenthedieandthepunch.Thereforethedieandthepuncharemadeoftoolsteelorcarbonsteel.一个工具向下推金属板料，使其进入一个有设计形状要求部分的腔中。拉深通常用于延展性好的材料如铝，黄铜，铜，和低碳钢。可成型的形状有：罐状，杯状，壶状，盘状。囫囵拉深系统由毛坯，压边圈，凸模，凹模组成。在凹模的上方是毛坯和压