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M o u l d & D i e N C c o m p u t e r - a i d e d T o o l o f S e l e c t i o nGeng TieStateKey Lab.ofMould&DieTechnology,HuaZhongUniversityof Scienceand TechnologyWuhan430074,ChinaIntroductionNC machiningtool path generationand tool selection,includingthetwo key issues.Beforea problemin the past 20 years has been wide-rangingand in-depthstudy,Many algorithmsfor the developmentof CAD CAM systemhas been appliedin the business.M ost CAM systemsto the userinput parameterswith automatictool path. Comparativelyspeaking,thequality,efficiencyand optimizationtool of choiceis far from mature.Currentlyno commercialCAM systemoptimizationtool can providedecisionsupporttools. it is difficultto achieveautomaticCAD CAM integrated.Tools typicallyincludetools and tool type size. In general,usuallyfor a processingtool targetinga varietyof differentprocessingtasksas well as the completionof a tool.Therefore,c onsideringonly meet thebasic requirementsof the tool selectionprocessis relativelyeasy,particularlyfor the holes,ducts,etc. typicalgeometricfeatures.Butin reality,and we usuallychoosethe optimaltool goals,such as themost efficient cutting, processingtime at least, the lowestmanufacturingcost, and the longestlife expectancy,and so on toolselectionis a complexoptimizationproblems.For example,die parts,complexgeometricshapes(usuallyfree surfaceand Island)Tool choicesaffect the geometricconstraintsin CAD modelcan not explicitthat it isnecessaryto design appropriateextractionalgorithm,choose theappropriatetools and tool specificationsportfolioto improve theefficiencyand qualityof NC is not an easy task.NC generalcavitywith the processingmethods,includingextensiveand usually,semi-finishingand finishingprocesses.Snag is the1principleof maximumextentpossiblethe efficientremovalof excessmetal and thereforewish to opt for largesize of the tool, But cuttersize is too large,might not lead to an increasein processingvolume;the main task is gettingextensiveand semi-finishedstageleft;finishedthe main componentsof the size and surfacequalityassurance.Takinginto accountthe currentelectionentirelyby the computerautomaticallyknifethereare stillcertaindifficulties,therefore,in our developmentof the c omputer-aidedtool selection(ComputerAidedTool Selection,CATS)system,basedon the usersto providea decision-supporttool,roughing,semi-finishingand finishing.the real decision-makingpower is left tousers,and to bringinto full play the advantagesof computer.1.Systemstructure.CATS systemfor CAD modelinput,outputtypesof tools,toolspecificationsMillingdepth,feed,SpindleSpeed(Speed)and theprocessingtime of six parameters(Figure1). Tool typesof options,includingdecision-supporttool,tool selectiondecision-supporttool forroughing.tool selectiondecision-supporttool for semi-finishingandfinishingtool selectiondecision-makingtools.Figure1 computer-aidedtool selectionof inputand outputGivenextensiveand importantpositionin the cavity(usually5-10 timesfinishingtime).snag when the systemis automaticallyoptimized2combinationof functionaltool to enhanceoverallprocessingefficiency.In additionto the abovedecision-makingtools,the systemalso has adetailedstandardizedtoolsto detect,Accordingto the recommendationofprocessingparametersand the size and type of tool to assessthefunctionof processingtime.Tool choiceof the finaltotalreturnsgenerated(Figure2). Tool Systemdata and knowledgeare all in supportof the backgrounddatabase.Figure2 CAD tool selectionand the basicfunctionmodules2 key technology and algorithms1) Toolsfor choiceAccordingdie NC practice,the tool generallyconsistsof MillingCutterpeace.Filletcutterand the cutterball three.Basedtool diameterD,the radiusr, r = 0 when the crew cutter.0R toolscan be dividedintothe overallstyleand framedchip.Tippedfor the ceremony,the key is toselectmaterialblades,bladematerialsare determinedby threefactors:the workpiecematerial,Machinetool fixtureand the stabilityof thecantilever.Workpiecematerialwill be processedinto steel,stainlesssteel,cast iron,nonferrousmetals,materialsand otherhard-to-cutmaterialsand hardwaresix. Stabilityjig into the well,less than threegrades.CantileverTool cantileveredinto shortand l ong cantilevertwo,the systemautomaticallyinductedbladematerialunderspecificcircumstances.WALTERTool knowledgecomesfrom the decision-makingmanuals,systemusersto choosethe firstinteractivetool types.TippedToolsof the rule-basedAutomated Reasoningbladessuitablematerial.Forexample,if the workpiecematerialas steel,the stabilityof thefixturegood tool for shortcantilevercantilever.Bladematerialwill beWAP25.32) PortfolioOptimizationTool snagThe objectiveis to maximizethe cavitysnag in the removalof excessmetal,used Ping Cutterand take all the layers.Therefore,the 3D dieroughingprocessis actuallya seriesof 2.5D die for processing.OptimizationTool Tool Groupsgoal is to find a combinationthat willenableit to the highestremovalefficiencyof most metals.The basicapproachis as follows: PortfolioOptimizationToolA. To do a certainstep in the directionperpendicularto the feed cavitysearchplaneand entitiesintersect,the formationsearchlayer.B. Deadlinefor submissionof outlineobtained.C. Calculationlink betweenor outsideof criticaldistancebetweentheislands,the choiceof toolsto influencethe geometricconstraint,thealgorithmshownin figure3.Figure3 key demandfrom the algorithm.D. Underthis principle(the distancebetweenadjacentkey differenceisless than a giventhreshold)levelof the searchfor a mergerPlaneprocessingand identifyviabletool sets,forminglayers.E. Each layerprocessingtool used to determinethat the combinationofthe tool cavity.F. Accordingto the recommendedprocessingtool parameters(cuttingspeed,feed rate and depthof milling),materialremovalrate calculation.G. Accordingto the actualremovalof the layerprocessingvolume,theprocessingtime is calculatedfor each layerprocessing.H. Calculatethe totalprocessingtime and residualvolumecavity.4I. The overallcompositionof this groupprocessingefficiencyassessmenttool.J. Ai repeateduntilthe optimalcombinationof the tool.If time goalthat the processingtime t requiredfor the entirecavitytool tooptimizethe combinationof the shortest.Basedon the abovemethodology,we can establishthe followingformaloptimizationmodel.MRRi=(dicij) (Nfz)(X cross-sectionalarea of cuttingfeed rate)Where: n-layerprocessingcavityvolume;M-layerprocessingeach of themillingcutternumber;l-processinglayerin the searcheach layervolume;q-layerprocessingeverytool possiblenumber;h-cavitydepth;cij -itime processinglayerj Millingdepth; aj - j cuttingarea of the baselayer;vi -i processingvolume;MRRi-i millinglayer,layerof materialremoval;di -i layerprocessingtool diameter;-i processinglayerdipviabletool set; rik -i processinglayerk ;e1 searchof the keydistance-control layerwith a constantsearch;e2 - residualvolumecontrolconstants;V-cavityvolume;DV - residualvolume;N-spindlespeed;f-cutterfeed per tooth;z-cutterteeth.Planetakinginto accountthe differentstepsin the searchprocesswillproducedifferentlevels,resultingin the processingtime and residualvolume,So sometimes,even thoughtotalprocessingtime shorter,but more5likelyto residualvolume.This showsthat the targetof a separateoptimizationof processingtime are not necessarilyscience.Therefore,the coefficientof efficiencyof the concept,consideringthe processingtime and the residualvolume,the processing time is shorter.lessresidualvolume,the higherthe efficiencycoefficient.Possession:On a middle-processingunit volumereflectsthe time factor,k =DV/Vpercentageof residualvolume.Thus,the efficiencycoefficientdefinedas q = 1/ Q .3) Semi-finishedTool SelectionThe main purposeis to removesemi-finishedroughingthe residuelevelcontourshape.For the completeremovalof height,depthmillingthe surfacemust be greaterthan the distancebetweeneach levelof xcomponents.Algorithmstepsare as follows:Step 1 modelwill have two partsfrom the adjacentsectionand thecorrespondingsurfacecontourlength;Step 2 calculationof the averagelengthprofile;Step 3 calculatingheightwidth;Step 4 Calculationof the cornerto level the surfaceof the parts todistancex law;Step 5 Repeatstepsfrom 1 to 4 steps,each step of the decisionMillingdepth;Step 6 curveof the diameterD, D=x/0.6Toolsmanualor recommendedbyexperience;Step 7 x greaterthan the minimumdepthof choicemillingcutter.4) finishedTool SelectionThe basicprincipleis : finishingtool selectiontool radiusR sizesmallerthan the smallestcurvatureradiusr surfaceparts.GeneraladmissionR = (0.80.9)r. The followingsteps:6Step 1 algorithmmodelfrom the smallestradiusof curvaturepartsentities;Step 2 retrievedfrom the databasetool cutterradiusless thanthe radiusof curvaturecalculationfor all tool;Step 3 selectthe best toolsto meet theserequirements;Step 4 : If all the toolsthan the smallestradiusof curvature.Minimumrecommendedas a tool of choice.3 implementationof the systemand examplesCATS systemin the C languageenvironmentUG/OPENAPI was developed.Backgroundfor the Oracle8i databaseusingODBC programmingand databasecommunicationsbetweenUG. All the data and knowledgefrom GermanyWALTERTool CompanyCarbideTool integrateds amples.Figure4 containsasculpturedsurfaceof the mold cavityand the island,accordingto thesnag in the portfoliooptimizationtool,The die-extensiveportfoliooptimizationtool for 20,12,8,5.Calculation,the workpiecematerialselectedfor carbonsteel,cuttingspeed100m/minrecommendedvalue.Millingdepthof two sixthtool diameter,feed rate accordingto therecommendedvaluesfrom the processtool that automaticallycalculated.Meanwhile,the assumptionthat the existinglevelCutterTool ToolLibrary specificationsfor f3, f4, f5, f6, f8 and f10, f12. f16, f20.Similarly,semi-finishingand finishingtool selectionalgorithm,thetool diameterball mill for 4 and 3.Figure4 containsthe islandand sculpturedsurfaceof the moldcavity74 Summaryand DiscussionThe planningprocessusuallydie of high technologyand exper