外文翻译机械设计理论.doc

MechanicaldesigntheoryThemechanicaldesignisaapplicationtechnicalsciencethroughdesignthenewproductorimprovestheoldproducttomeetthehumanneed.Itinvolvesalldomainoftheprojecttechnology,mainlyresearchsizeoftheproduct,basicideaoftheshapeandthedetailedstructure,alsoresearchquestionofmanufacture,saleanduseoftheproductinallaspects.Theyusuallycalleddesignerormechanicaldesignengineerwhocarriesoneachkindofmechanicaldesignwork.Themechanicaldesignisacreativework.Designengineernotonlyhavethecreativityinthework,butalsohavethedeepelementaryknowledgeonmechanicaldrawing,kinematics,engineeringmaterial,materialsmechanicsandmachinemanufacturetechnology.Assaysabove,thegoalofmechanicaldesignistheproductioncanmeetthehumanneed.Theinvention,thediscoveryandtechnicalknowledgeitselfcertainlynotnecessarilycanbringtheadvantagetothehumanity,onlywhentheyareappliedontheproductcanproducethebenefit.Thus,weshouldrealizewhetherpeopledoneedthiskindofproductbeforecarryonthedesigninaspecificproduct.Themechanicaldesignmustregardasagoodopportunityforthemechanicaldesignertousecreativeabilitycarriesonproductdesign,thesystematicanalysisandformulatemanufacturetechnologyoftheproduct.Graspingtheprojectelementaryknowledgeismoreimportantthanmemorizingsomedataandtheformula.Merelyusingthedataandtheformulaisinsufficienttocompletelydecidealldecisioninagooddesign.Ontheotherhand,theyshouldcarryonalloperationsprecisely.Forexample,evenifplaceadecimalpointinwrongposition,alsocanturnthecorrectdesigntowrong.Newdesignscanhavemanyflawsandproblemsunexpected,onlytheseflawsandthequestionhavebeensolved,cannewproductssuperioritybemanifested.Therefore,asuperiorproductbornfollowedahigherriskatthesametime.Whatshouldemphasizeisthatifdesignsitselfdoesnotrequesttousethebrand-newmethod,itisnotnecessarytousethenewmethodmerelyforthegoalfortransformation.Inthepreliminarystageofdesign,shouldallowdesignerfullytodisplaythecreativity,notrestrainttoeachkindofrestraint.Evenifhavemanyimpracticalideasinearlytime,theycanalsobecorrectedbeforeplanblueprint.Onlyinthiswaycannotstoptheinnovation.Usually,mustproposeseveralsetsofdesignproposals,andthenperformthecomparison.Itispossiblethatsomeideashavebeenusedinthefinalplanwhichisnotacceptedbefore.Thepsychologistfrequentlydiscussesthecausesofhowcouldpeopleadapttomachinewhichoperate.Adesignerspersonnelsbasicresponsibilityisdiligentlycausesthemachinetoadaptthepeople.Thiscertainlyisnotaneasywork,becausethemostsuperioroperatingareaandtheoperatingprocesstoalldonotexistinfact.Anotherimportantquestion,projectengineermustbeabletocarryontheexchangetheconsultationwithotherconcernedpersonnel.Intheinitialstage,designerhastoexchangewithadministratoronthepreliminarydesign,andbeapproved.Thisisgenerallythroughtheoraldiscussion,withschematicdiagramandthewritingmaterial.Inordertocarryontheeffectiveexchange,needstosolvethefollowingproblem:(1)Whetherproductdesignedistrulyneededforthepeople?(2)Whetherthisproducthascompetitiveabilitycomparewithothercompanysexistingsimilarproducts?(3)Whetherthiskindofproductiseconomical?(4)Whetherthisproductsserviceconvenient?(5)Whetherthisproductsalewell?Whethercangain?Onlytimebeabletoproducethecorrectanswertoabovequestion.But,theproductdesign,themanufactureandthesaleonlycancontinueonfoundationoftheabovequestionpreliminaryanswered.Projectengineeralsoshouldconsulttogetherwiththebranchofmanufactureforthefinallydesignproposalthroughthedetaildrawingandtheassemblydrawing.Usually,canhavesomeprobleminthemanufactureprocess.Possiblycanrequesttosomecomponentssizeorthecommondifferencemakessomechanges,causesthecomponentstheproductiontochangeeasily.But,intheprojectchangemusthavetopassthroughdesignsthepersonneltoauthorize,guaranteedcannotdamagetheproductthefunction.Sometimes,wheninfrontofproductassemblyorinthepackingforeignshipmentexperimentonlythendiscoversinthedesignsomekindofflaw.Theseinstancesexactlyshowedthedesignisadynamicprocess.Alwayshasabettermethodtocompletethedesignwork,designsthepersonneltobesupposedunceasinglydiligently,andseeksthisbettermethod.Recentyear,theengineeringmaterialchoicealreadyappearedimportantly.Inaddition,thechoiceprocessshouldbetothematerialcontinuouslytheunceasingagainappraisalprocess.Thenewmaterialunceasinglyappears,butsomeoriginalmaterialscanobtainthequantitypossiblycanreduce.Theenvironmentalpollution,materialrecyclingaspectandsoonuse,workershealthandsecurityfrequentlycanattachthenewlimitingconditiontothechoiceofmaterial.Inordertoreducetheweightorsavestheenergy,possiblycanrequesttheusedifferentmaterial.Comesfromdomesticandinternationalcompetition,toproductservicemaintenanceconveniencerequestenhancementandcustomersaspecttheandsoonfeedbackpressure,canurgethepeopletocarryontothematerialreappraises.Becausethematerialdoesnotselectwhencreatedtheproductresponsibilitylawsuit,hasalreadyhadtheprofoundinfluence.Inaddition,thematerialandbetweenthematerialprocessinginterdependenceisalreadyknownbythepeopleclearly.Therefore,inordertocanandguaranteesthequalityinthereasonablecostunderthepremisetoobtainsatisfactiontheresult,projectengineermakesengineersalltohaveearnestlycarefullytochoose,thedeterminationandtheusematerial.Makesanyproductthefirststepofworkallisdesigns.Designsusuallymaydivideintoseveralexplicitstages:(a)preliminarydesign；(b)functionaldesign；(c)productiondesign.Inthepreliminarydesignstage,thedesigneremphaticallyconsideredtheproductshouldhavefunction.Usuallymustconceiveandconsiderseveralplans,thendecidedthiskindofthoughtiswhetherfeasible；Ifisfeasible,thenshouldmakesthefurtherimprovementtoorseveralplans.Inthisstage,thequestionwhichonlymustconsideraboutthechoiceofmaterialis:Whetherhastheperformancetoconformtotherequestmaterialtobepossibletosupplythechoice；Ifno,whetherhasabiggerassuranceallpermitsinthecostandthetimeinthelimitdevelopsonekindofnewmaterial.Inthefunctionaldesignandtheengineeringdesignstage,needstomakeapracticalfeasibledesign.Mustdrawupthequitecompleteblueprintinthisstage,choosesanddetermineseachkindofcomponentsthematerial.Usuallymustmaketheprototypeortheworkingmodel,andcarriesontheexperimenttoit,theappraisalproductfunction,thereliability,theoutwardappearanceandtheservicemaintenanceandsoon.Althoughthiskindofexperimentpossiblycanindicate,entersintheproducttotheproductionbaseinfrontof,shouldreplacecertainmaterials,but,absolutelycannotthispointtakenotearnestlychoosesthematerialtheexcuse.Shouldunifytheproductthefunction,earnestlycarefullyconsiderstheproducttheoutwardappearance,thecostandthe