模具设计的外文翻译

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1、模具设计的外文翻译TheInjectionMold--ThedesignofRunner1.ThebasicTherunnerisachannelmachinedintothemodplatetoconneelthespruewiththeentrance(gate)totheimpression.Inthebasictwo-platemodtherunnerispositionedonthesurfacewhileonthemorecomplexdesignstherunnermaybepositionedbelowthepartingsurfaceThewallofther

2、unnerchannclmustbesmoothtopreventanyrestrietiontoflow.Also,astherunnerhastoberemovedwiththemolding,theremustbenomachinemarksleft,whichwouldtendtoretaintherunnerinthemodplate.Toensurethatthesepointsaremet,it'sdesirableforthemoddesignertospecifythattherunner(channel)ispolished'inlineofdraw".Th

3、erearesomeotherconsiderationsforthedesignertobearinmind:(i)theshapeofthecrosssectionoftherurm(ii)thesizeoftherunner.Runnercross-sectionshapeThecross-sectionalshapeoftherunnerusedinamodisusuallyoneoffourforms(Figure4.2):fullyround(a),trapezoidcil(b),modifiedtrapezoidal(c)andhexagonal(d).There

4、asonwhytheseparticularformsareusedinprefereneetoothersareoutlinedbelow.Thecriterionofefficientrunnerdesignisthattherunnershouldprovideamaximumcross-sectionalareafromthestandpointofpressuretransferandminimumcross-sectionalareatoperipherywill,therefore,giveadirectindicationoftheefficiencyofthe

5、runnetdcsign;therunnersectionarcgiverinFigure4.3.Ascanbeseen,thevarioustypesofstandpoint;whereastheratiosexhibitedbythesemicircularandrectangulartypesmaketheirusegenerallyundesirable.Unfortunately,thesquarerunnerisnotverysatisfactoryeither,butforanotherreason:itisdifficuIttoeject.Inpractice,

6、becauseofthis,anangleof10°isincorporatedontherunnerwell,thusmodifyingthesquaretothetrapezoidalsection.Thevolumeofthetrapezoidalrunnerisapproximatcly25%greatorthanthatofaroundrunnerwithcorrespondingdimensions(W=D,Figure4.2).Toreducethisdiffereneeandstillmaintaincorrespond!ngdimensions,amodifi

7、edtrapezoidalformhasbeendeveloped(Figure4.2c)inwhichthevolumeisonly14%greater(approximately)thanitsroundcounterpart.Thehexagonalrunnerisbasicallyadoubletrapezoidalrunner,wherethecross-sectionalareaofthisrunnertypeisabout82%ofthatofthecorrespondingr