硕士论文-弧面凸轮等温挤压预成形工艺与模具结构优化

湘潭大学硕士学位论文弧面凸轮等温挤压预成形工艺与模具结构优化姓名：张海筹申请学位级别：硕士专业：材料工程指导教师：胡自化2006050134MSC.Marc12:K3HAILGCr15C020750±190pt=3MSC.Marc4:K35AbstractAtpresent,automationequipmentsmadeinourcountryarenormallyequippedwithwormgearmechanisms,whichhavebiggerclearancesbetweenthepositiveandnegativedirectionsandworseresistingtorqueabilityatwork.Moreover,becauseofthelaggardtechnicalmeansofmanufacturingandassembly,thehomemadewormgearmechanismsaremuchworsethantheinternationalhigh-qualityonesintherespectsofindexingaccuracy,repeatedindexingaccuracyandloadingcapacity.Becauseoftheinextensibilityofthecontoursurfaceofthegloboidalcam,BarpreformsmostlyareusedtobemachinedonCNCmachinetoolsorshapedmillingmachineintheconventionalcuttingtechnique.Thentheremainingmaterialtoberemovedisgreat,andthemetalstreamlinesofthebarpreformswillbedestroyedduringthecuttingprocess.thusthecomponentscompositivemechanismperformanceareaffected.Sothemulti-axisNCmachinesmustbeusedtomakeahighaccuracygloboidalcam,butthetechniquecostsrestrictitspopularizationbyalongway.AlongwiththebroadapplicationintheCNCmachinetoolsandthepackingmechanisms,globoidalcamshaveshownitssuperioritysuchashighefficiencyhighaccuracyandhighstableperformanceinthehigh-speedintermittentmechanisms.Untilrecentyears,theresearchesandthediscussionsofthemachiningtechniquemethodsforgloboidalcamshavefurtherbeingdevelopedinourcountry.Thispaperproposesatechniquemethodcalledisothermalextrusiontomakepreforms,andoptimizethemouldstructurebyusingMSC.MarcFEMsoftware.Accordingtotheresearchonthistypeofdrivingmechanisms,themainworkofthepaperisasfollows:(1)Deducingthecurveequationofcontoursurfaceofthegloboidalcam:applyingthemeshingpropertybetweenthecamandrollers,andtheturn-backprincipleifthecamisstatic,therollersturnbackandswingaroundthecam’saxisatthesametime,andderivatethegloboidalcammechanismssurfacecurvingequation.(2)Establishingthepre-formingtechniqueofthegloboidalcam:useK3-alloyasthestructurematerialoftheHalf-mould,andheatedthebasematerialasGCr15toC020750±soon,thenusetheIsothermalExtrusionPre-formingtogainthepreformsofthegloboidalcamundertP190=.(3)UsingtheMSC.MarcFEMsoftwaretoanalyzeandcertificatethefeasibilityofisothermalextrusiontechnique,andoptimizetheconcavemouldcavity.Theemphasesistheeffecttothefillperformanceoftheisothermalextrusiontechnique,andensurethefavorablefillingperformancebyperfectingthesizeofthemould.6(4)Foundingapowder-mixedEDMtechnologyfortheconcavemouldcavity:owingtothehighintensityofK3-alloyandtheinextensibilityofthecontoursurfaceoftheinteriorconcavemouldcavitystructure,theconventionalmillcan’tcarrythrough,andthegeneralEDMcan’tmeettheneededroughnessdegree.Theninthispapertheprocessoftheinteriorconcavemouldcavityispowder-mixedEDMtechnology.Inaword,thedevelopedmanufacturetechniqueforthegloboidalcam’spreformsinthisthesisrevolutionizesthetraditionalbarperformstechnique,theisothermalextrusionpre-formingisusedtoholdtheforgebasewithshortprocesstime,highmaterialutilizationratio,greatmachinerysynthesizeandgoodsurfacequality.Keywords:globoidalcams;isothermalextrusion;pre-formingtechnique;optimizationofmouldstructure;rigidandviscoplasticfiniteelementmethod.91.115001200500[1]1.1101.11321.2(OloboidalIndexingCamMecbanisrn)(RollerGearIndexingCamMechanismsFecygusonDriveForIndexingMachineC.N.NeklutinFerguson1[2][3]2[4][5][6]3NTXK5001110002mm''7±800rminCADCAM[7][8]4Nearnetshapetechniquenetshapetechnique30400t300MW600MW[9]1234312100mmx100mm0.12Ramµ37mmφ0.13Ramµ1.31CAD23132.1[10]1.12.12.1Nr16Nr60Nr24n1000rpnn600rpmn2000rpm153015301030142.22.2.1[11]2.12.2152.12.2.22.22.3XYZXZZcωcϕtϕC'δ2.316tϕcϕ()()1/ttccmϕϕϕϕ==m2.3()0,csϕδ()()0,cossincttsaiKϕδδϕδϕ=−−2-1()cKω−(),pcsϕδ()[]()()cossin0,cos,0,sinsincos0001coscoscossinsinccpcttcctctctsaaiajkϕϕϕδδϕδϕϕϕδϕϕδϕϕδϕ−==−−=−−−−2-2[15]nppcxyzppcSSnninjnkSSδϕδϕ∂∂×∂∂==++∂∂×∂∂2-3()r(),csϕδ()()()()(),,,,,cpcxcyczcSSrnSiSjSϕδϕδϕδϕδϕδ=±=++2-42.3CAD2.3.1()ttcϕϕϕ=[15]2.4172-400tϕ=12mm1Icϕϕ=2-521IIccϕϕϕ=−2-632IIIccϕϕϕ=−2-73360IVcϕϕ=°−2-80tϕ01234tttttϕϕϕϕϕ=+++()()()()11121221212112211112222IIIIIIIIVIVIIIIVIIIIIIVrmmmmmmmmmmKϕϕϕϕϕϕϕϕϕϕϕϕϕ=++−+++−=+++++=2-911221122IIIIVIIIIIIVABϕϕϕϕϕϕ=++=++2-10120360tmAmBABϕ+=+=°2-11212112360360rrKAmmmNKBmmmN°=−−°=−−2-120360AA°°12rrKmNKmN2-13AB=IIIIϕϕ=122rKmmN+=2-142.3.21K=12rN=18IIIIABϕϕ==2-14122211126rKmmN×+===1112rKmN=2112rKmN=60Iϕ=°1110m=2-14211161015m=−=2-12AB1118022IIIIVAϕϕϕ=°=++2.52.6191118022IIIIIIVBϕϕϕ=°=++IϕIIϕIIIϕIVϕ[16]60Iϕ=°120IIϕ=°60IIIϕ=°120IVφ=°ctϕϕ−'ctϕϕ−ctϕϕ−2.52.62.7[17]2.8125.000amm=82.500Rmm=min42.194dmm=95.350Lmm=max122.500Dmm=2.82.720GCr153.13.1.1GCr156.0~4.0=fεC0550~5000.8fε=CNCNCN3.1.2GCr15GCr153.1213.1GCr15CSiCrMnPS0.951.050.150.351.301.650.200.400.030.033.1.33.10.70fε=1.5S140S-13.1GCr153-2GCr153.2GCr1522500c°GCr15500c°3.2GCr153.2GCr153.2GCr15bMPa6145.4713.031.36504.53514.548.06953.50521.350.37251.77853.876.27871.31671.998.08351.1279.499.4725c°1.778bMPaσ=614c°5.47bMPaσ=100c°2/3,δψδ40%ψ1835c°1.12MPa79.4%ψ99.4%3.1.43.3GCr1520%80%700c°0.40fε=5.60MPa0.80fε=11.60MPa1600c°600c°3.3GCr1523mR