机械毕业设计英文外文翻译544雨 刷.docx
- 文档编号:29602293
- 上传时间:2023-07-25
- 格式:DOCX
- 页数:10
- 大小:41.99KB
机械毕业设计英文外文翻译544雨 刷.docx
《机械毕业设计英文外文翻译544雨 刷.docx》由会员分享,可在线阅读,更多相关《机械毕业设计英文外文翻译544雨 刷.docx(10页珍藏版)》请在冰豆网上搜索。
机械毕业设计英文外文翻译544雨刷
附 录A
WindshieldWiper
Background
Windshieldwipersareusedtocleanthewindshieldofacarsothatthedriverhasanunobstructedviewoftheroad.Atypicalwipeangleforapassengercarisabout67degrees.Thebladesare12-30in(30-76cm)longwithlengthsincreasingin2-in(5-cm)increments.
History
Thehistoryofthewindshieldwiperbeganwiththeinventionoftheautomobile.Mosttransportationvehiclesdidnothavewipers.Horse-drawncarriagesandtrucksmovedatslowspeeds,andglasswasnotneededtoprotectthedriverorpassengersortoactasawindbreak.
Thefirstwindshieldwiperswerebrushes.InventorJ.H.Apjohncameupwithamethodofmovingtwobrushesupanddownonaverticalplateglasswindshieldin1903.Inthesameyear,MaryAndersondevisedaswingingarmthatsweptrainoffthewindshieldwhenthedrivermovedaleverlocatedinsidethecar.Andersonpatentedherinventionofthemechanicalwindshieldwiperin1905,anditbecamestandardequipmentby1913.Electricmotorswerenotusedyettopowerautomobileessentialsoraccessories,andAnderson'sdevicehadadrawback.Withoutanotherpowersource,adriverhadtouseonehandtomovethelever.Thedriver'sotherhandsteeredthecar(witheitherawheelorsteeringtiller)andworkedthestick-mountedgearshiftandbrakegripsstandingonthefloorofthecaroroutsidethedriver'ssideontherunningboard.
Rubberstripsreplacedbrushesasthecleaningtoolsonwipersin1905.Unfortunately,thehazardousneedfordriverstowipewindshieldswhiledrivingwasnoteliminateduntil1917.Thesolutionwastouseanelectricmotortomoveasinglewiperwithalongrubberbladebackandforth.HawaiiandentistDr.OrmandWallinventedtheautomaticwiperbyplacinganelectricmotorinthetopcenterofthewindshieldsothewiperarceddownoverthehoodofthecarinasemi-circularorrainbowshape.Wiperswereoneofthefirstelectricaldevicesinautomobilesaftertheelectricstarterwasdevelopedin1912.Mostwipersoncarsbefore1930werepairedandhungdownfromthetopofthewindshield.Theyweremovedtothebaseofthewindshieldaselectricalsystemsbecamemorecomplicated.
Windshieldwasherswereaddedtothewiperon/offlevers,andtheserequiredspraynozzlesinfrontofthewindshield,atankforwasherfluidintheenginecompartment,andelectricalconnectionstocoordinatetheseoperations.In1962,BobKearnsinventedtheintermittentwiperwithintervalsandspeedsthatthedrivercouldchange.Theadventofelectronicsystemswithfusesandcircuitbreakerstooperate,regulate,andcoordinateelectricalcomponentsexpandedthepossibilitiesformorediversewipers.Wiperswereaddedtoheadlightsinthe1980s,requiringconnectionsbetweenthelightingandwipersystems.Inthe1990s,microsensorswerebuiltintowindshieldstodetectrainonthewindshield,activatethewipers,andadjustspeedandintermittentusefortheamountofrain.
RawMaterials
Themanufacturerpurchasesallofthepartsfromcompaniesthatspecializeinfabricatingpartsfromaluminumandsteel,rubberblades,plasticbushingsforthelinkages,andthemotors.Windshieldwipersandwindshieldwipersystems(withmotors)aredifferentassemblies;somemanufacturersmakeboth,andothersproducewipersonly.
Theconnectinganddrivelinksandthepivotsthatmovethewipersaremadeofgalvanizedsteel.Galvanizationistheprocessofapplyingzinccoatingtosteeltoprotectitfromcorrosion.Drivearmsforboatsandvehiclesusedinthemarineindustryaremadeofstainlesssteelthatresistsdamagefromsaltwater.Thewipersuspensionandclawsarealsogalvanizedsteel.Thegalvanizingzinccoatingiseasiertopaintthanuncoatedsteel.Steelisalsothematerialinthesmallpartsofwipers,suchaswashers,screws,nuts,springs,andbrackets.
Thebladeframeismadefromaluminum.Thebladesaremadeofnaturalrubberorsyntheticcompounds.Somerubberbladesarecompositesofsoftrubberonthewipingedge(thesqueegeesurface)andfirmrubberthatsupportsthewipingedgeintherestoftheblade.
Othermaterialsthatcomprisepartsofwindshieldwipersarerubberforwashersinthepivotsandplasticbushingsthatlineholesforconnectingpartsofthelinkage.Thewipersuspensionistypicallypaintedblack.Ifthewipermanufactureralsobuildswipersystems,motorsarepurchasedfromsubcontractors.Themotorsarecontainedinsteelhousingsandincludepermanentmagnetmotorswoundwithcopperwire.Eachhousinghasconnectionsfortheelectricalwiresthatarepartofthevehicleandwiringharnessesarefurnishedspecifictooperatingthewipers.Eachmotoralsocontainsoneormoreelectroniccircuitsdependingonthesophisticationofthesystemthatthemotorcontrols.
Design
Windshieldwipersaredesignedandmadetoclearwaterfromawindshield.Mostcarshavetwowipersonthewindshield,andtheymayhaveoneontherearwindowandoneoneachheadlight.Thewiperpartsvisiblefromoutsidethecararetherubberblade,thewiperarmholdingtheblade,aspringlinkage,andpartsofthewiperpivots.Thewiperitselfhasuptosixpartscalledpressurepointsorclawsthataresmallarmsunderthewiper.Theclawsdistributepressurefromthewiperalongthebackoftheblade.Thisisdescribedasabalancebeamwithasuspensionsystem,wherethewiperisthebeamandtheclawsarethesuspensioncomponents.Theclawskeepthebladeflexedagainstthewindshieldtodistributeevenpressuretocleantheglassallalongtheblade.Moreclawsusuallydistributethepressurebetterandaresuitedtolargeorhighlycurvedwindshields.
Althoughtherubberisthefamiliarpartoftheblade,thebladeactuallyincludesametalstripcalledabladeframewithaslotalongthelengthoftheframeandreplacementholesintheframe.Thereplacementholesprovideaccessforreplacingtherubberbladewitharefill.Thebladeonitsaluminumframecanalsobechangedasaunit.
Thestandardtwowindshieldwipersareusuallyoperatedasasingle-motor,tandemschemewithonewiperonthedriver'ssideandonepositionednearthemiddleofthewindshieldthatmovesacrossthepassenger'sview.Thewipersaresecuredtopivots.Awiperandpivotaremountedonbracketsatbothendsofalongrodcalledtheconnectinglink,and,astheforcefromthemotorpushesonthedriver'sendoftheconnectinglink,itinturnmovestheotherwiper.Theconnectinglinkisattachedtoanotherlongrodcalledthedrivelinknearthewipermotor.Aslenderspringlinkagetiesthepivottothedrivelinktoreturnthewipertoitsrestingorparkposition,hugthewiperclosetothewindshield,andkeepitattachedtothecarifthelinksaredamaged.
Betweenthemotorandthedrivelink,alinkagesystemconsistingofacam(anothershortrod)andpivot,agearoutputshaft,andawormgearcontrolstheforceofthemotordeliveredtothedrivearm.Thewormgearslowsthespeedofthemotorwhilemultiplyingitstorque(force).Thegearallowsasmallmotortoproduceenoughforcetomovethebladesacrosstheglass.Thisdescriptionisbasedonusingasinglemotortodrivebothwipers.Ifonemotorpowerseachwiper,morelinksareneededtomovethetwowiperstogetherinaso-calledunitizedmotorsystem.
Thismultipliedforceisrequiredtoacceleratethebladesfrombeingstoppedatboth
Windshieldwipersystems.
endsoftheirmovement,toresistthefrictionoftherubberagainsttheglass,toresistthefrictionoftherubberondirtontheglass,andtoopposewindpressureonthewindshield.
QualityControl
Duringassembly,theworkersobservetheconditionsofthepartsduringtheirwork,buttheironlyspecificqualitycontrolactivityistochecktheoperationofthemotorsbyturningthemontomakesuretheystartandbylisteningtothesoundstheymakeasindicationsofperformance.
Thelastinspectionisperformedwhentheassembliesarecompleteandbeforethewipersandsystemsarepacked.Themanufacturingdirectororfinalqualitycontrolinspectorslookatthegeneralappearanceoftheassemblies,confirmthatthewipershavebeensizedandangledcorrectlyfortheirsweep,andcheckthattheassembliesareintheparkposition.Thedirectororinspectorsalsochecktoseethatthecorrectaccessoriesarereadytobepackedwiththeassemblies.
Byproducts/Waste
Smallquantitiesofsteelandaluminumscrapsfromtrimmingsorrejectedordamagedpartsarecollectedinbinsandsoldtosalvagedealerswho,inturn,sellthemtometalmanufacturerswhomeltthescrapdownforrecycling.Packagingfromreceivedpartsisalsocollectedandrecycled.
TheFuture
Asof2002,windshieldwipersandwipersystemsareevolvingbecauseofchangesinautomobilesandothervehicles,technicalimprovements,andconsumerdemand.Wiperbladesareasmuchas30in(76cm)long,creatingmoreresistanceastheycleanthewindshield.Night-visionscreensforwindshieldsareindevelopment,andthesealsoincreaseresistanceandchangethedimensionsneededforwipers.Bladesarebeingimprovedwithincreasinglyflexiblerubber,so-called"boots"thatfitaroundthebladestokeepouticeandsnow,andnonstickcoatingsonthesqueegeeedgesofthebladestokeepoilandwaxfromadheringandagingthem.
Motorsystemsarealsobeingincreasedinvoltagetopowerlongerwipersandmoreaccessories.Engineersareinvestigatingfullyautomatedsystemsthatdonotrequireanyactionsbydriverstostartandstopwipersystems.Inventorsexpectthecapabilitiesoftherain-detectingsensorsavailableinthelate1990stowidentopromptthewiperstocleandirtywindshieldswithnorain,forexample.Windshieldwipersareamongmostreliablea
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 机械毕业设计英文外文翻译544雨 机械 毕业设计 英文 外文 翻译 544