模具专业英语 教学课件 作者 王浩钢 14456第20章.ppt

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1、Lesson20BenchFittingIrrespectiveofthemachinetoolortechniqueusedtomanufacturethevariouspartsofthemould,thefinalresponsibilityforthefinishingoftheindividualpartsandforfittingthemtogetherlieswiththebenchfitter.Themouldfinishingandassemblyprocedureadoptedbythebenchfittervariesfr

2、omtoolroomtotoolroom;itisthereforeimpossibletosetdownastandardpatternforthework.Inconsequence,weintendonlytoindicatethegeneralapproachtothisproblemwithoutgoingintodetails.Wewilldothisbyconsideringthevariousstagesinthebenchfittinginvolvedinthemanufactureofasimplemould.Thevari

3、ousstagesarelistedasfollows.Stage1.FinishingtheimpressionWhenthemouldplatesarereceivedfromthemachinetoolsection,theimpressionform(onbothplates)isintheroughmachinedstate.Cuttermarks,burrs,etc.,areveryapparentonthesurface.Thebenchfitter’sfirstjobistoproduceacavityandcorefreeof

4、machinemarksandtotheshapeanddimensionsspecifiedonthemoulddetaildrawing.①Stage2.AligningcavityandcoreThisoperationistoalignthetwopartswithrespecttoeachothersothatthemoldingproducedwillhavethecorrectwallsection.Thisisachievedbyusingpackingpiecesbetweenthecavityandcore.Thetwomo

5、uldplatesareclampedtogetherandreturnedtothemillingorjigboringmachinetohaveguideholesboredthroughbothplates.Whenthisoperationiscomplete,theclampsareremoved,themouldplatesseparatedandtheguidepillarsandguidebushesfitted.Thetwomouldplatesareagainbroughttogetherandcheckedtoensure

6、thatthecoreisinalignmentwiththecavity.Stage3.BeddingdownThisistheprocessof‘marrying’thetwoopposingmouldhalvestogethertopreventtheplasticmaterialescapingbetweenthetwosurfaceswhenthematerialisinjectedintotheimpression.②Onesurface(thecoreplateinourexample)isgivenaveryfinecoatin

7、goftoolmaker’sblue.Thetwoplatesarethenmomentarilybroughttogetherandwheretherearehighspotsonthesecondmouldplate(thecavityplateinourexample),bluewillbepickedup.Thesehighspotsareremovedbyscrapingandfiling.Stage4.WatercoolingcircuitTheholesdrilledforthewatercirculationinthemould

8、platesaretappedandplugs,baffles,orconnectorsfittedasappropriate.Stage5.Fitt