lesson57工程師在機(jī)械制造業(yè)中的作用

1、Lesson31therolesofengineersinmanufacturing第三十一課第三十一課工程師在機(jī)械制造業(yè)中的作用工程師在機(jī)械制造業(yè)中的作用Manyengineershaveastheirfunctionthedesigningofproductsthataretobebroughtintorealitythroughtheprocessingfabricationofmaterials.Inthiscapacityth

2、eyareakeyfactinthematerialionmanufacturingprocedure.Adesignengineerbetterthananyotherpersonshouldknowwhatheshewantsadesigntoaccomplish.Heknowswhatassumptionshehasmadeaboutserviceloadsrequirementswhatserviceenvironmentthe

3、productmustwithstwhatappearancehewantsthefinalproducttohave.Indertomeettheserequirementshemustspecifythematerial(s)tobeused.Inmostcasesindertoutilizethematerialtoenabletheproducttohavethedesiredfmheknowsthatcertainmanufa

4、cturingprocesseswillhavetobeemployed.Inmanyinstancestheionofaspecificmaterialmaydictatewhatprocessingmustbeused.Atthesametimewhencertainprocessesaretobeusedthedesignmayhavetobemodifiedinderftheprocesstobeutilizedeffectiv

5、elyeconomically.Certaindimensionaltolerancescandictatetheprocessing.Inanycaseinthesequenceofconvertingthedesignintorealitysuchdecisionsmustbemadebysomeone.Inmostinstancestheycanbemademosteffectivelyatthedesignstagebythed

6、esignerifhehasareasonablyadequateknowledgeconcerningmaterialsmanufacturingprocesses.Otherwisedecisionsmaybemadethatwilldetractfromtheeffectivenessoftheproducttheproductmaybeneedlesslycostly.Itisthusapparentthatdesignengi

7、neersareavitalfactinthemanufacturingprocessitisindeedablessingtothecompanyiftheycandesignfproducibility—thatisfefficientproduction.許多工程師的職責(zé)是進(jìn)行產(chǎn)品設(shè)計(jì)而產(chǎn)品是通過(guò)對(duì)材料的加工制造而生產(chǎn)出來(lái)的。設(shè)計(jì)工程師在材料選擇制造方法等方面起著關(guān)鍵的作用。一個(gè)設(shè)計(jì)工程師應(yīng)該比其他的人更清楚地知道他的設(shè)計(jì)需要達(dá)到

8、什么目的。他知道他對(duì)使用荷載和使用要求所做的假設(shè)產(chǎn)品的使用環(huán)境產(chǎn)品應(yīng)該具有的外觀形貌。為了滿(mǎn)足這些要求他必須選擇和規(guī)定所使用的材料。通常為了利用材料并使產(chǎn)品具有所期望的形狀設(shè)計(jì)工程師知道應(yīng)該采用哪些制造方法。在許多情況下選擇了某種特定材料就可能意味著已經(jīng)確定了某種必須采用的加工方法。同時(shí)當(dāng)決定采用某種加工方法后很可能需要對(duì)設(shè)計(jì)進(jìn)行修改以使這種加工方法能夠被有效而經(jīng)濟(jì)地應(yīng)用。某些尺寸公差可以決定產(chǎn)品的加工方法?？傊趯⒃O(shè)計(jì)轉(zhuǎn)變?yōu)楫a(chǎn)品的過(guò)程

9、中必須有人做出這些決定。在大多數(shù)情況下如果設(shè)計(jì)人員在材料和加工方法方面具有足夠的知識(shí)他會(huì)在設(shè)計(jì)階段做出最為合理的決定。否則做出的決定可能會(huì)降低產(chǎn)品的性能Lowcostmanufacturingdoesnotjusthappen.Thereisacloseinterdependentrelationshipbetweenthedesignofaproductionofmaterialsionofprocessesequipmenttool

10、ingiondesign.Eachofthesestepsmustbecarefullyconsideredplannedcodinatedbefemanufacturingstarts.Thisleadtimeparticularlyfcomplicatedproductsmaytakemonthsevenyearstheexpenditureoflargeamountofmoneymaybeinvolved.Typicallythe

11、leadtimefacompletelynewmodelofanautomobileisabout2yearsfamodernaircraftitmaybe4years.低成本制造并不是自動(dòng)產(chǎn)生的。在產(chǎn)品設(shè)計(jì)、材料選擇、加工方法和設(shè)備的選擇工藝裝備選擇和設(shè)汁之間都有著非常密切的相互依賴(lài)關(guān)系。這些步驟中的每一個(gè)都必須在開(kāi)始制造前仔細(xì)地加以考慮、規(guī)劃和協(xié)調(diào)。這種從產(chǎn)品設(shè)計(jì)到實(shí)際生產(chǎn)的準(zhǔn)備工作特別是對(duì)于復(fù)雜產(chǎn)品可能需要數(shù)月甚至數(shù)年的時(shí)間并且可

12、能花費(fèi)很多錢(qián)。典型的例子有對(duì)于一種全新的汽車(chē)從設(shè)計(jì)到投產(chǎn)所需要的時(shí)間大約為2年而一種現(xiàn)代化飛機(jī)則可能需要4年。Withtheadventofcomputersmachinesthatcanbecontrolledbyeithertapesmadebycomputersbythecomputersthemselvesweareenteringaneweraofproductionplanning.Theintegrationofthede

13、signfunctionthemanufacturingfunctionthroughthecomputeriscalledCADCAM(computeraideddesigncomputeraidedmanufacturing).Thedesignisusedtodeterminethemanufacturingprocessplanningtheprogramminginfmationfthemanufacturingprocess

14、esthemselves.Detaileddrawingscanalsobemadefromthecentraldatabaseusedfthedesignmanufactureprogramscanbegeneratedtomakethepartsasneeds.Inadditionextensivecomputeraidedtestinginspection(CATI)ofthemanufacturedpartsistakingpl

15、ace.Thereisnodoubtthatthistrendwillcontinueateveracceleratingratesascomputersbecomecheapersmarter.隨著計(jì)算機(jī)和由計(jì)算機(jī)產(chǎn)生的紙帶與由計(jì)算機(jī)本身控制的機(jī)器的出現(xiàn)我們進(jìn)人了一個(gè)生產(chǎn)計(jì)劃的新時(shí)代。采用計(jì)算機(jī)將產(chǎn)品的設(shè)計(jì)功能與制造功能集成被稱(chēng)為“DCAM(計(jì)算機(jī)輔助設(shè)計(jì)計(jì)算機(jī)輔助制造)。這種設(shè)計(jì)被用來(lái)制定加工工藝規(guī)程和提供加工過(guò)程本身的編程信息?？?/p>