外国工程师传授的产品设计资料

外國工程師傳授的design資料，供大家享受。bbs.icax.cn9s0l#ffb$ZK[HInjectionMoldingDesignGuidelinesCAD/CAM/CAE综合资讯网站论坛i3xxIoM注塑模具设计指导www.iCAx.cnN]-u{1mMuchhasbeenwrittenregardingdesignguidelinesforinjectionmolding.Yet,thedesignguidelinescanbesummedupinjustafewdesignrules.已经有许多关于设计注塑模具的书了,但是设计准则可以被概括以下几点:iCAx开思论坛9m$|h9VAhUseuniformwallthicknessesthroughoutthepart.Thiswillminimizesinking,warping,residualstresses,andimprovemoldfillandcycletimes.1.零件整体壁厚保持均匀.这样可以最小化缩坑,翘曲,强度减小,模具填充和循环时间.4Ln
?d-H%`3dI,}Usegenerousradiusatallcorners.Theinsidecornerradiusshouldbeaminimumofonematerialthickness.2.在转角处大量采用圆角.圆角内部最小半径为一个壁厚.Usetheleastthicknesscompliantwiththeprocess,material,orproductdesignrequirements.Usingtheleastwallthicknessfortheprocessensuresrapidcooling,shortcycletimes,andminimumshotweight.Alltheseresultintheleastpossiblepartcost.www.iCAx.cn3[G+d^&\W3.根据工艺,材料,产品设计需求.采用最小壁厚.最小壁厚的应用可以确保快速的冷却,短循环时间和减少喷射重量.所有这些最终达到最小的产品成本.Designpartstofacilitateeasywithdrawalfromthemoldbyprovidingdraft(taper)inthedirectionofmoldopeningorclosing.CAD/CAM/CAE综合资讯网站论坛4l6Z7v.V2jQ0G%~4.在模具开合方向设置拔模角便于设备的运做.Useribsorgussetstoimprovepartstiffnessinbending.Thisavoidstheuseofthicksectiontoachievethesame,therebysavingonpartweight,materialcosts,andcycletimecosts.5.为了提高产品强度抵抗弯曲应该加筋或肋.避免用厚的结构达到同样的效果,以此减少了产品重量,材料成本,循环时间成本.TheuseofribsiCAx开思论坛8o.y+p-pt*C筋的应用Ribsincreasethebendingstiffnessofapart.Withoutribs,thethicknesshastobeincreasedtoincreasethebendingstiffness.Addingribsincreasesthemomentofinertia,whichincreasesthebendingstiffness.Bendingstiffness=E(Young'sModulus)xI(MomentofInertia)如果没有筋来增加强度,厚度就必须增加(费话一堆).加强筋增加了转动惯量!Theribthicknessshouldbelessthanthewallthickness-tokeepsinkingtoaminimum.Thethicknessrangesfrom40to60%ofthematerialthickness.Inaddition,theribshouldbeattachedtothebasewithgenerousradiusingatthecorners.筋的厚度要壁厚,以降低缩坑.厚度推荐=40%~60%壁厚.另外筋应该在根部倒圆角.Atribintersections,theresultingthicknesswillbemorethanthethicknessofeachindividualrib.Coringorsomeothermeansofremovingmaterialshouldbeusedtothindownthewallstoavoidexcessivesinkingontheoppositeside.在筋交叉的截面处,壁厚要单独的筋,为了防止在反面产生缩坑,尽量出去交叉中心的材料.Theheightoftheribshouldbelimitedtolessthan3xthickness.Itisbettertohavemultipleribstoincreasethebendingstiffnessthanonehighrib.筋的高度3倍的厚度.最好多加几条代替一个.Theriborientationisbasedonprovidingmaximumbendingstiffness.Dependingonorientationofthebendingload,withrespecttothepartgeometry,ribsorientedonewayincreasestiffness.Iforientedthewrongwaythereisnoincreaseinstiffness.iCAx开思论坛%I筋的方向布置以增加产品强度为准,参考弯曲载荷方向(其他为费话)Draftanglesforribsshouldbeminimumof0.25to0.5degreeofdraftperside.iCAx开思论坛.L'C1vy]Ifthesurfaceistextured,additional1.0degreedraftper0.025mm(0.001inch)depthoftextureshouldbeprovided.拔模角单边0.25~05度,表皮有皮纹,没增加0.025毫米+1度.BossDesignbbs.icax.cno}.p&LBX!]#|.w,v2DlBossesareusedforthepurposeofregistrationofmatingpartsorforattachingfastenerssuchasscrewsoracceptingthreadedinserts(molded-in,press-fitted,ultrasonicallyorthermallyinserted).为了配合或者为了连接如螺钉,或者有螺蚊的插入(注入,压接,超生地或热的插入),引入了柱.Thewallthicknessesshouldbelessthan60%ofnominalwalltominimizesinking.However,ifthebossisnotinavisiblearea,thenthewallthicknesscanbeincreasedtoallowforincreasedstressesimposedbyself-tappingscrews.www.i为了防止缩坑,厚度保持在60%的壁厚,如果柱在不可见部分,可以根据自攻螺钉的强度要求适当增加厚度.Thebaseradiusshouldbeaminimumof0.25xthicknessiCAx开思论坛|xf)[1_F最小半径=0.25壁厚.Thebosscanbestrengthenedbygussetsatthebase,andbyattachingittonearbywallswithconnectingribs.www.iCAx.cn,}b'XfbY为了增强柱的强度,在根部加筋并且把它和周围的筋相连.Hoopstressesareimposedonthebosswallsbypressfittingorotherwiseinsertinginserts.www.iCAx.cn$r周向应力会在配合或者插入时会被施加在柱上.Themaximuminsertion(orwithdrawl)forceFmaxandthemaximumhoopstress,ocurringattheinnerdiameteroftheboss,smaxisgivenby最大的的插入力和周向应力发生在内直径.iS9VFailuresofabossareusuallyattributableto:CAD/CAM/CAE综合资讯网站论坛se6H(Z&MAD失败的柱的原因归为以下:Highhoopstressescausedbecauseoftoomuchinterferenceoftheinternaldiameterwiththeinsert(orscrew).c@4t+c0s!h@]|+pp[由于内部直径的过多干涉造成了周向应力变大.Knitlines-thesearecoldlinesofflowmeetingatthebossfromoppositesides,causingweakbonds.Thesecanspliteasilywhenstressisapplied.结合线-在柱相反方向相遇的形成大冷线,导致脆弱.CAD/CAM/CAE综合资讯网站论坛)\OsXD;^Knitlinesshouldberelocatedawayfromtheboss,ifpossible.Ifnotpossible,thenasupportinggussetshouldbeaddedneartheknitline.把结合线移开,如果可能的话.如果实在不可行,在接结合线附近加筋.SnapLatches•Snapsallowaneasymethodofassemblyanddisassemblyofplasticparts.Snapsconsistofacantileverbeamwithabumpthatdeflectsandsnapsintoagrooveoraslotinthematingpart.对于塑料件卡扣提供了一个简便的拆装方法.卡扣由一个突起和凹槽或缝配合组成.•Snapscanhaveauniformcross-sectionorataperedcrosssection(withdecreasingsectionheight).Thetaperedcross-sectionresultsinasmallerstraincomparedtotheuniformcross-section.Hereweconsiderthegeneralcaseofabeamtaperinginbothdirections.卡扣可以有同意的截面或者成角度的.跟前者比后者有更小的应变.这里我们以便推荐两面有倾角的.WhenRh=1andRb=1,theaboveformuladoesnotapply,L'Hospital'sruleappliesandtheformulaissimplifiedtothefollowing:•Disassemblyforce.Thedisassemblyforceisafunctionofthecoefficientoffriction,whichrangesfrom0.3to0.6formostplastics.Thecoefficientoffrictionalsovarieswiththesurfaceroughness.Therougherthesurface,thehigh