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1、本科畢業(yè)論文(設(shè)計(jì))相關(guān)中英文翻譯資料資料題目:機(jī)械加工學(xué)生姓名:所在院系:機(jī)電學(xué)院所學(xué)專業(yè):機(jī)電技術(shù)教育完成時(shí)間:MachiningTurningTheenginelathe,oneoftheoldestmetalremovalmachines,hasanumberofusefulandhighlydesirableattributes.Todaytheselathesareusedprimarilyinsmallshopswheresmallerquantitiesratherthanlargeproductionrunsareencountered.Theenginelathehasbe
2、enreplacedintodaysproductionshopsbyawidevarietyofautomaticlathessuchasautomatictracerlathes,turretlathes,andautomaticscrewmachines.Alltheadvantagesofsingle-pointtoolingformaximummetalremoval,andtheuseofformtoolsforfinishedonaparwiththefastestprocessingequipmentonthescenetoday.Tolerancesfortheenginel
3、athedependprimarilyontheskilloftheoperator.Thedesignengineermustbecarefulinusingtolerancesofanexperimentalpartthathasbeenproducedontheenginelathebyaskilledoperator.Inredesigninganexperimentalpartforproduction,economicaltolerancesshouldbeused.TurretLathesProductionmachiningequipmentmustbeevaluatednow
4、,morethaneverbefore,intermsofabilitytorepeataccuratelyandrapidly.Applyingthiscriterionforestablishingtheproductionqualificationofaspecificmethod,theturretlathemeritsahighrating.Indesigningforlowquantitiessuchas100or200parts,itismosteconomicaltousetheturretlathe.Inachievingtheoptimumtolerancespossibl
5、eontheturretlathe,thedesignershouldstriveforaminimumofoperations.AutomaticScrewMachinesGenerally,automaticscrewmachinesfallintoseveralcategories;single-spindleautomatics,multiple-spindlerapid,automaticchuckingmachines.Originallydesignedforrapid,automaticproductionofscrewsandsimilarthreadedparts,then
6、arrowfield,andtodayplaysavitalroleinthemassproductionofavarietyofprecisionparts.Quantitiesplayanimportantpartintheeconomyofthepartsmachinedontheautomaticscrewmachine.Thecostofthepartsmachinedcanbereducediftheminimumeconomicallotsizeiscalculatedandthepropermachineisselectedforthesequantities.Automati
7、cTracerLathesSincesurfaceroughnessdependsgreatlyuponmaterialturned,tooling,andfeedsandspeedsemployed,minimumtolerancesthatcanbeheldonautomatictracerlathesarenotnecessarilythemosteconomicaltolerances.Insomecases,tolerancesof0.05mmareheldincontinuousproductionusingbutonecut.Groovewidthcanbeheldto0.012
8、5mmonsomeparts.Boresandsingle-pointfinishescanbeheldto0.0125mm.Onhigh-productionrunswheremaximumoutputisdesirable,aminimumtoleranceof0.125mmiseconomicalonbothdiameterandlengthofturn.MillingWiththeexceptionsofturninganddrilling,millingisundoubtedlythemostwidelyusedmethodofremovingmetal.Wellsuitedandr
9、eadilyadaptedtotheeconomicalproductionofanyquantityofparts,thealmostunlimitedversatilityofmillingprocessmeritstheattentionandconsiderationofdesignersseriouslywiththemanufactureoftheirproduct.Asinanyotherprocess,partsthathavetobemilledshouldbedesignedwitheconomicaltolerancesthatcanbeachievedinproduct
10、ionmill.Ifthepartisdesignedwithtolerancesfinerthannecessary,additionaloperationswillhavetobeaddedtoachievethesetolerances-andthiswillincreasethecostofthepart.GrindingGrindingisoneofthemostwidelyusedmethodsoffinishingpartstoextremelyclosetolerancesandfinesurfacefinishes.Currently,therearegrindersfora
11、lmosteverytypeofgrindingmachinerequired.Whereprocessingcostsareexcessive,partsredesignedtoworthwhile.Forexample,whereverpossibletheproductioneconomyofcenterlessgrindingshouldbetakenadvantageofbyproperdesignconsideration.Althoughgrindingisusuallyconsideredafinishingoperation,itisoftenemployedasacompl
12、etemachiningprocessonworkwhichcanbegrounddownfromroughconditionwithoutbeingturnedorotherwisemachined.Thusmanytypesofforgingsandotherpartsarefinishedcompletelywiththegrindingwheelatappreciablesavingsoftimeandexpense.Classesofgrindingmachinesincludethefollowing:cylindricalgrinders,centerlessgrinders,i
13、nternalgrinders,surfacegrinders,andtoolexpense.Thecylindricalandcenterlessgrindersortaperwork;thussplines,shafts,andsimilarpartsaregroundoncylindricalmachineseitherofthecommon-centertypeorthecenterlessmachine.Threadgrindersareusedforgrindingprecisionthreadsforthreadgages,andthreadsonprecisionpartswh
14、eretheconcentricitybetweenthediameteroftheshaftandpitchdiameterofthreadmustbeheldtoclosetolerances.Theinternalgrindersareusedforgrindingofprecisionholes,cylinderbores,andsimilaroperationswhereboresofallkindsaretobefinished.Thesurfacegrindersareforfinishingallkindsofflatwork,orworkwithplainsurfaceswhichmaybeoperateduponeitherbytheedgeofawheelorbythefaceofagrindingwheel.Thesemachinesmayhavereciprocatingorrotatingtables.