机电专业英语 教学课件 作者 杨寿智 刘水平 机电专业英语.Lesson 10.ppt

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1、Lesson10DieComponentsTextThecomponentsgenerallyincorporatedinablankingorpiecingdieareshowninFig.10.1(a).Thecuttingtoolassemblyisshownintheconventionalclosedposition.Thediesetismadeupofthepunchholder,whichfastensdirectlytotheramofthepunchpress,andadieshoe,whichfas

2、tenstothebolsterplateofthepunchpress.Guidepostsmaybeusedtobetteralignthepunchholderwiththedieshoe.Thediesetmaybepurchasedwithtwoguidepostslocatedattherearofthedieset（calledbackposts）,diagonally,oneintherearandoneinthefrontofthedieset,orwithfourposts,oneineachcorn

3、er.Intheconventionalpositionthepunchholderispressfittedwithbushings.Theguidepostsandthebushingshaveaslipfitsothattheguidepostsmaymovefreelyinthebushings.Theoppositeendsoftheguidepostsarepressfittedintothedieshoe.Thepunchisfastenedtothepunchholderandalignedwiththe

4、openinginthedieblockwhichisfastenedtothedieshoe.Sincethepunchanddieblockarethecuttingtools,theyarebothhardened.Oncethecuttingactionhastakenplace,thepunchstartstoretract.Becauseofthenatureofthematerialtheholeinthescrapstripcontractsandthestripclingstothepunch,wher

5、eastheblank(workpiece)expandsandclingstothedieopening.Astrippingactionisneededtofreethescrapstripfromthepunch.ThestrippershowninFig.10.1(a)isthesimplestofsuch.Itspurposeistoaligntheblankandstripthescrapoffthepunchontheupstroke.Othertypesofstrippersusedarespringpa

6、dsorplates;somearehydraulicallyoperated.Besidestheclingingofthescraptothepunchandtheclingingoftheblanktothedieopening,athirdsetofforcesisoperating.Theblankalsoadherestothefaceofthepunch.Iftheforcesholdingtheblanktothefaceofthepuncharegreaterthantheforcesholdingth

7、eblankinthedieopening,push-offpinsarenecessarytohelptheblankfreeitselffromthepunchface.Thisisusuallynecessaryforthinblanksorblankswhichhavebeentreatedwithalubricant.TheshutheightpositionofthedieassemblyisshowninFig.10.1(a)withthevariouscomponentscrosshatchedtoavo

8、idhiddenlinesandconfusion.Sometimesitisadvisabletoshowtheassemblywiththerighthalfintheclosedpositionandtheleftoftheassemblyintheopenposition.Otherdrawingconven