《機械加工工藝》課件-1.7The selection of blank type

1234blanktypecontentsblankselectionblankshapetoconsider1、blanktypecastingforgingssectionweldment(1).casting1、Sandcasting:1)Woodenmoldsarehand-shaped:singlepiecesmallbatchproduction,largepieces2)metalmould,machinemolding,mediumandsmallpartsinmassproduction2.Metalmoldcasting:Mainlycastnon-ferrousmetals3.Centrifugalcasting：Alargenumberofrotaryparts.4Diecasting:Inmassproduction,complexstructure,smallsize,itisnotheavycoloredparts.SandcastingCentrifugalcastingPressurecastingPrecisioncastingForroughblankswithcomplexshapes,castingsshouldbeusedasroughblanks.castingcastingSandcastingPressurecastingPrecisioncastingmetalmoldcasting2、forgingsSpecialforgingdie,highprecision,smallallowance,highstrength,highefficiency,itissuitableformassproduction.Forginghammerorpressmachine,manualoperationaccuracyislow,largeallowance,lowproductivity,Itissuitableforsinglesmallbatchproductionandlargeforgings.dieforgingopendieforgingforgingsdieforgingopendieforgingLargeprocessingallowance,lowprecisionforgings,lowproductivity,itissuitableforsingleandsmallbatchproduction,aswellaslargeforgingsproduction.Smallprocessingallowance,highprecisionforgings,highproductivity,itissuitableforsmallandmediumforgingswithlargeoutput.3.sectionSmallsize,highprecision,expensive,easytorealizeautomaticfeedinglowprecision,lowprice,

itisusedfortheblankthataregeneralparts.colddrawhotrollingsectionroundsteelsquaresteelhexagonalsteelflatsteelanglesteelchannelsteelhot-rolledprofilescold-drawnprofilesLargesize,lowprecision,itismostlyusedfortheblankthataregeneralparts.Smallsize,highprecision,Itismainlyusedtomanufacturemediumandsmallpartswithhighprecision4.simplemanufacturing,shortcycle,lightweightoftheblank,

singlepiecesmallbatchproductionweldmentadvantagesdisadvantagespoorvibrationresistanceandlargedeformation，ItisnecessarytoproducelargeblankafteragingtreatmentweldmentForlargeparts,theweldingpartsaresimpleandconvenient,butthepartsoftheweldingpartshavealargedeformation,andcanbemachinedafteragingtreatment.pressmachine、compressingdie，highprecision，smallRa，highefficiency，itissuitableformassproduction，smallpartswithsimpleshapes。Stamping

partspunchingmachine、stampdie，highprecision、highefficiency，itisuitableforlargebatchandsmallpartsthicknessofsmallsmallpartspowdermetallurgyColdForgingPartsMetalpowderasrawmaterial,inthepressthroughthemoldpressingmoldingafterhightemperaturesintering.Highefficiency,highprecision,smallRa,cannolongerfinishmachining,butthecostishigh,suitableforalargenumberofmassproduction,theshapeissimplesmallparts.二、Theselectionprincipleofblank（1)Accordingtothematerialandrequirementofthepartstoselect（2)AccordingtothestructureandshapeofthepartsSteppedshaft：Thedifferenceisnotbig,userodstomakeunimportantstepshafts;Thedifferenceislarge,whetherthestepshaftisimportantornot,useforgingstosavematerialandreducelabor.Plateconditions：forgingsforuncomplicated;weldingforthecomplexSize：Thelargeronesarecastin