模具专业英语Unit1(1)课件

Unit1InjectionMolding陈显冰

Overview1.1Theinjectionmolding

Injectionmoldingisamethodofproducingplasticparts.Thisisdonewithaninjectionmoldingmachine.Theshapeoftheparttobeinjectionmoldediscontrolledbythegeometryoftheinjectionmold.Theinjectionmoldingmachinehastwobasicparts;theinjectionunit,whichmeltstheplasticandtheninjectsormovesitintothemold,andtheclampingunit,whichholdstheinjectionmold.注射成型是生产塑料部件的方法。他由注塑机来完成。注塑成型的部件形状受到注塑模具的几何形状控制。注塑机有两个基本部分；注入装置，它可融化塑料，然后把塑料注入或移动至模具中，锁模装置，它可夹住注塑模具。

Injectionmoldingisprincipallyusedfortheproductionofthethermoplasticparts,althoughsomeprogresshasbeenmadeindevelopingamethodforinjectionmoldingsomethermosettingmaterials.Theproblemofinjectingameltedplasticintoamoldcavityfromareservoirofmeltedmaterialhasbeenextremelydifficulttosolveforthermosettingplasticswhichcureandhardenundersuchconditionswithinafewminutes.Theprincipleofinjectionmoldingisquitesimilartothatofdie-casting.Theprocessconsistsoffeedingaplasticcompoundinpowderedorgranularformfromahopperthroughmeteringandmeltingstagesandtheninjectingitintoamold.Afterabriefcoolingperiod,themoldisopenedandthesolidifiedpartejected.Injection-moldingmachinescanbearrangedformanualoperation,automaticsingle-cycleoperation,andfullautomaticoperation.Theadvantageofinjectionmoldingare:Ahighmoldingspeedadaptedformassproductionispossible;Thereisawidechoiceofthermoplasticmaterialsprovidingavarietyofusefulproperties;Itispossibletomoldthreads,undercuts,sideholes,andlargethinsections.

尽管成型某些热固性材料的方法取得了一定进步，但注塑模主要还是用来生产热塑性塑件。这主要是因为热固性塑料熔体在很短的时间内就会固化和硬化，在从料斗向模具型腔注入热固性塑料熔体的过程中，也会出现这种情况，这个问题一直非常难解决。注塑成型原理和铸造十分相似。注塑成型的工艺过程包括：首先把料斗中的粉状或粒状的塑料混合物依次输送到计量区和熔化区，然后再注射到模具型腔中，经过短时冷却后，开模，推出成型塑件。注塑机分为手动、半自动及全自动操作。注塑模具有以下优点：较高的成型速度使大批量生产成为可能；为成型具有不同使用性能的热塑性材料提供了较宽的选择；可以成型带有螺纹的塑件、侧向凹陷的塑件、带有侧孔的塑件以及较大的薄壁件。1.2Theinjection-moldingstructure

Theinjectionmouldisanassemblyofpartscontainingwithinitan“impression”intowhichplasticmaterialisinjectedandcooled.Itistheimpressionwhichgivesthemouldingitsform.Theimpressionmay,therefore,bedefinedasthatpartofthemouldwhichimpartsshapetothemoulding.注塑模具是由几部分组合在一起形成成型腔，塑料熔体注入成型腔，并在成型腔内冷却成型。是成型腔形成了塑件的形状。因此，成型腔被定义为模具的成型部件。Theimpressionisformedbytwomouldmembers:thecavity,whichisthefemaleportionofthemould,givesthemouldingitsexternalform.Thecore,whichisthemaleportionofthemould,formstheinternalshapeofthemoulding.成型腔由两部分组成：型腔，即模具的母模部分，形成塑件的外部形状。型芯，即模具的公模部分，形成塑件的内部形状。1)Cavityandcoreplates

Thebasicmouldinthiscaseconsistsoftwoplates.Oneplateissunkintothecavitywhichshapestheoutsideformofthemouldingandisthereforeknownasthecavityplate.Similarly,thecorewhichprojectsfromthecoreplateformstheinsideshapeofthemouldingisclosed,thetwoplatescometogetherformingaspacebetweenthecavityandcorewhichistheimpression.最简单的模具包括两块模板。一块模板下陷形成型腔，用于形成塑件的外部形状，这块模板被称为型腔板。同理，型芯板上凸起的型芯加工塑件的内部形状。这两块板拼合起来，在型腔和型芯之间形成的空间就是成型腔。2)Spruebush

Duringtheinjectionprocessplasticmaterialisdeliveredtothenozzleofthemachineasamelt;itisthentransferredtotheimpressionthroughapassage.Thematerialinthispassageistermedthesprue,andthebushiscalledaspruebush.注塑过程中，塑料以熔融状态从注塑机喷嘴射出，然后流过一通路进入模具成型腔。熔体流过的通路称作主流道，其衬套被称作浇口套。3)Runnerandgatesystems

Thematerialmaybedirectlyinjectedintotheimpressionthroughthespruebushorformouldscontainingseveralimpressionsitmaypassfromthespruebushholethrougharunnerandgatesystembeforeenteringtheimpression.塑料熔体可能经过浇口套直接进入模具一个或几个型腔，或者熔体从浇口套流出，经过分流道和浇口系统再进入型腔。4)RegisterringIfthematerialistopasswithouthindranceintothemould,thenozzleandspruemustbecorrectlyaligned.Toensurethatthisisso,themouldmustbecentraltothemachineandthiscanbeachievedbyincludingaregisterring.如果想让熔体没有任何阻碍地进入模具，注塑机的喷嘴和模具主流道必须位于同一轴线上。为确保正确安装，模具必须安装在注塑机的中心部位，（我们可以）通过使用定位圈达到这一目的。5)Guidepillarsandbushes

Tomouldaneven-walledarticle,itisnecessarytoensurethatthecavityandcorearekeptinalignmemt.Thisisdonebyincorporatingguidepillarsononemouldplatewhichthenentercorrespondingguidebushesintheothermouldplateasthemouldcloses.若加工具有均匀壁厚的塑件，必须确保型腔和型芯在同一轴线上，这可以依靠导柱和导套实现。导柱安装在一块模板上，合模时进入安装在另一块模板上对应的导套里。6)Fixedhalfandmovinghalf

Thevariousmouldpartsfallnaturallyintotwosectionsorhalves.Hence,thathalfattachedtothestationaryplatenofthemachine(indicatedbythechaindottedline)istermedthefixedhalf.Theotherhalfofthemouldattachedtothemovingplatenofthemachineisknownsimplyasthemovinghalf.Nowithastobedecidedinwhichofthetwohalvesthecavityorcoreistobesituated.Generallythecoreissituatedinthemovinghalfandtheoverridingreasonwhythisisso,isasfollows:各种模具结构（虽然不同，但均）可以划分为两个部分或部件。因此，固定在注塑机固定板的部分称为定模部分，同理，固定在注塑机移动板的部分即为动模部分。这样，模具被安装在注塑机上。通常型芯安装在动模部分，其原理如下：

Themoulding,asitcools,willshrinkontothecoreandremainwithitasthemouldopens.Thiswilloccurirrespectiveofwhetherthecoreisinthefixedhalforthemovinghalf.However,thisshrinkageontothecoremeansthatsomeformofejectorsystemisalmostcertainlynecessary.

（塑件）冷却后开模，由于熔体的收缩作用使塑件紧紧地包在型芯上，这与型芯是安装在定模部分还是安装在动模部分无关。然而，塑件包紧在型芯上意味着必需使用某种形式的推出系统。如果型芯安装在动模部分，推出系统运动的动力很容易获得，此外，单型腔模具中，熔体直接进入模具内部，型腔必须固定在定模部分，型芯必须安装在动模部分。1.3Injection-moldingmachine

Severalmethodsareusedtoforceorinjectthemeltedplasticintothemold.Themostcommonlyusedsysteminthelargermachines(asshowninFigure1.1)isthein-linereciprocatingscrew,asshowninFigure1.2.Thescrewactsasacombinationinjectionandplasticizingunit.Astheplasticisfedtotherotatingscrew,itpassesthroughthreezonesasshown:feed,compression,andmetering.Afterthefeedzone,thescrew-flightdepthisgraduallyreduced,forcingtheplastictocompress.Theworkisconvertedtoheatbyshearingtheplastic,makingitasemifluidmass.Inthemeteringzone,additionalheatisappliedbyconductionfromthebarrelsurface.Asthechamberinfrontofthescrewbecomesfilled,itforcesthescrewback,trippingalimitswitchthatactivatesahydrauliccylinderthatforcesthescrewforwardandinjectsthefluidplasticintotheclosedmold.Anantiflowbackvalvepreventsplasticunderpressurefromescapingbackintothescrewflights.熔融塑料注入模具中通常有几种方式。在大型注塑机(如图1.1所示)上常采用往复式螺旋注塑的注入方式，如图1.2所示。螺杆同时具有注射和塑化的功能。树脂原料进入旋转的螺杆时，要经过图示的三个区域：喂入区、压实区和计量区。经过喂入区后，为压实树脂原料，螺杆螺旋部分的深度逐渐降低，同时传递树脂原料间因剪切作用而产生的热量，使原料呈半流动状态。在计量区，螺缸表面的加热装置对熔体进一步加热。当熔体充满螺杆前部区域时，螺杆在熔体压力的作用下后退，触动限位开关使液压缸工作，在液压力的作用下推动螺杆向前运动，将熔融塑料注射到闭合的模具型腔中。防倒流阀能够阻止受压熔体倒流进螺杆的螺旋区。Theclampingforcethatamachineiscapableofexertingispartofthesizedesignationandismeasuredintons.Arule-of-thumbcanbeusedtodeterminethetonnagerequiredforaparticularjob.Itisbasedontwotonsofclampforcepersquareinchofprojectedarea.Iftheflowpatternisdifficultandthepartsarethin,thismayhavetogotothreeorfourtons.注塑机的锁模系统所提供的锁模力由（塑件在分型面的投影）尺寸决定，锁模力以吨为单位。通常靠经验来决定塑件所需要的锁模力总吨数，一般在塑件投影面积上每平方英寸需要作用两吨锁模力。如果熔体流动困难或塑件较薄，锁模力应提高到三到四吨。Manyreciprocating-screwmachinesarecapableofhandingthermosettingplasticmaterials.Previouslythesematerialswerehandledbycompressionortransfermolding.Thermosettingmaterialscureorpolymerizeinthemoldandareejectedhotintherangeof375℃～410℃.Thermoplasticpartsmustbeallowedtocoolinthemoldinordertoremovethemwithoutdistortion.Thusthermosettingcyclescanbefaster.Ofcoursethemoldmustbeheatedratherthanchilled,aswiththermoplastics.许多往复螺杆式注塑机能生产热固性塑料。以前，热固性塑料由挤出模具或传递模具生产。热固性塑料熔体在模具内固化或发生聚合反应，并在温度为375℃～410℃范围内推出。热塑性塑料熔体必须在模具内冷却成型，以保证推出时不发生变形。这种热固性循环速度很快。当然，生产热塑性塑件时，模具必须被加热，而不是冷却。Injection-moldingmachinescanbearrangedformanualoperation,automaticsingle-cycleoperation,andfullautomaticoperation.Theadvantageofinjectionmoldingare:1)ahighmoldingspeedadaptedformassproductionispossible;2)thereisawidechoiceofthermoplasticmaterialsprovidingavarietyofusefulproperties;3)itispossibletomoldthreads,undercuts,sideholes,andlargethinsections注塑机分为手动、半自动及全自动操作。注塑模具有以下优点：较高的成型速度使大批量生产成为可能；为成型具有不同使用性能的热塑性材料提供了较宽的选择；可以成型带有螺纹的塑件、侧向凹陷的塑件、带有侧孔的塑件以及较大的薄壁件。EXERCISEQuestions1．Whatarethecomponentsofinjection-molding?2．Howdoesthereciprocating-screwinjectionsystemwork?3.Whataretheadvantageofinjectionmolding?ReadingMaterial：BasicsofInjectionMolding

Injectionmoldingisamanufacturingtechniqueformakingpartsfromboththermoplasticandthermosettingplasticmaterialsinproduction.Moltenplasticisinjectedathighpressureintoamold,whichistheinverseoftheproduct'sshape.Afteraproductisdesigned,usuallybyanindustrialdesigneroranengineer,moldsaremadebyamoldmaker(ortoolmaker)frommetal,usuallyeithersteeloraluminium,andprecision-machinedtoformthefeaturesofthedesiredpart.Injectionmoldingiswidelyusedformanufacturingavarietyofparts,fromthesmallestcomponenttoentirebodypanelsofcars.Injectionmoldingisthemostcommonmethodofproduction,withsomecommonlymadeitemsincludingbottlecapsandoutdoorfurniture.注塑成型是一种制造技术，在生产中用于制造由热塑性和热固性塑料材料组成的零部件。熔化的塑料以高压被注入到了模具中，此过程是形成了产品的相反形状。通常情况下，在由工业设计师或工程师设计完成产品后，由模具制造商（或工具商）制造由金属（通常是钢或铝）组成的模具，然后经过精密加工塑造所期望部件的特征。注塑成型广泛用于制造各种零部件，从最小的零部件到整个汽车的车身壁板。注塑成型是最常见的生产方法，还通常用于制造某些物品包括瓶盖和室外家具。1)EjectorStopperAblockthatstopsanejectorplatefromgoingforward[stoppin]1.顶出板制动装置它是阻止顶出板向前运动的障碍物。2)EjectorPlateEjectorPlateisalsocalledapushplate.Aplatesupportsanedgeofanejectorpinorapushbackpintoejectapartfromamold.Itisejectedbyanejectordeviceofamoldingmachine,andreturnedtotheoriginalpositionwhentheedgeofapushbackpincollideswithacavityplateduringmoldclamping.2.顶出板顶出板也被称为推出板。此板支撑推顶杆的边缘或回推销使零部件从模具中推出。3)StopPinAstopperinstalledtokeepanejectorplatehorizontalorpreventtheejectorplatefromretreatingtoofaranddamagingacoreadaptorplate.3.止动销已安装的制动装置使顶出板保持水平或防止推出器模板退离过远并破坏型芯安装板。4)PushRodsAshaftlinkedtotheforce(hydraulicormechanical)ofthemoldingmachineinordertogettheejectorplatetowork.4.推杆连接在注塑机上的轴可产生力使顶出板工作。5)EjectorGuidePins/EjectorGuideBushAnejectorguidepinisalsocalledapushplateguidepinandfunctionsasaguideforslidingofanejectorplate.Becauseanejectorguidebushslides,ahardmaterialisused.Anejectorguidebushisalsocalledapushplateguidebush.Itisacylindricalpartusedtodeterminethepositionbymatchingtheejectorguidepin.5.顶出导销/顶出导套顶出导销也被称为推板导销，起到顶出板的导轨槽作用。因为顶出导套滑动，所以使用较硬的材料。顶出导套也被称为推板导套。它是一个确定与顶出导销匹配位置的圆柱形部件。6)GasSpring/GasSpringHolderAgasspringforciblypushesbackanejectorplate.Thestrengthofthespringisadjustedbyadjustingthefillingpressure.Whenusingagasspring,makesuretoavoidhightemperature(heatmayexpandgas,deterioratingtheoriginalfunctionsofagasspring).CalculatingFillingPressureTofigureoutfillingpressure(P)fromearlyload(Wo):P=100*Wo/C(C:constant)Tofigureoutcorrespondingspringconstant(K)fromfillingpressure(P)andgasspringconstant(G):K=G*P/100Tofigureoutforcebydisplacement(x)fromthetopofthepistonrod(W):W=P(Gx+C)Seethecatalogofeachmanufacturerforconstant(C)andgasspringconstant(G).6.气压弹簧/气压弹簧支架气压弹簧可用力推回顶出板。弹簧的强度可通过充气压力调节。当使用气压弹簧时，一定要避免高温。计算充气压力由最初负荷计算充气压力：P=100*Wo/G由充气压力和气压弹簧常数计算相应的弹簧常数：K=G*P/100由距离活塞杆顶部的位移计算力：W=P(Gx+C)7)GasSpringHolderAgasspringholderisablockusedtofixagasspringtoanejectorplate.Counterboreprocessforaboltinstallationhole,foritalsofunctionsasapushrod.7.气压弹簧支架气压弹簧支架是用于把气压弹簧固定到顶出板的部件。因为它也起着推杆作用，所以具有用于螺栓连接的沉孔工艺。8)SprueLockPinsApinhastheedgeofwhichisundercuttopullapartinmoldopeningandremoveaspruefromaspruebush.Aftermoldopening,thispinwillfunctionasanejectorpinandejectsthespruefromaapruebush.Alsoitreleasesgascontainedinmoltenplastic.8.浇口锁销浇口锁销有一个侧向分型的边，这样在模具打开时可拉出零部件，并可从浇口套中除去一个浇口。模具打开后，锁销将起到顶出销的作用并从浇口套中推出浇口。同时也释放了已熔化塑料中的气体。ForReference:GlanceattheStructureoftheDie1.Adjustpin(Knock-outbar):Apinorbartypicallyattachedtotheupperportionofthediesetthatforcesthefinishedpieceout.2.Punchholder:Anothertermusedfortheupperdieshoe.3.Backingplate：Aplateusedtosupportthehardwareforthecavityusedinplasticsinjectionmolding.4.Punchplate:Ametalplateontowhichthevario