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ASummaryofSmall-sizeExcavatorsHomeandAbroadI.ThebriefintroductionofhydraulicexcavatorPartssuchasthehydraulicexcavatorisbyengine,hydraulicsystemandworksdeviceandwalksdeviceandelectriccontroletcareformed.Thehydraulicsystemisformedbyhydraulicpump,controlvalve,hydrauliccylinder,hydraulicpressuremotor,piperouteandfueltanketc.Theelectriccontrolsystemincludessupervisiondish,motorcontrolsystem,pumpbrainandvariouskindsofsensorandsolenoidvalvesetc.Thehydraulicexcavatorisgeneralbytheworkdeviceandturnsroundthedeviceandwalksdevicethreeismostlyformed.Accordingtohisconstructionanduse,wecandifferentiate:manykindsoftypessuchascaterpillartreadtype,tyretype,walktype,fullhydraulicpressure,halfhydraulicpressure,turnsroundentirely,notturnsroundentirely,utilityversion,mouldforaspecialpurpose,thejoiningwithahingetypeandarmtypestretchedoutanddrawnbacketc.Theworkdeviceisdirectlyaccomplishingthedevicethatexcavatestheassignment.Ithasbeenjoinedwithahingebymovesthearm,fightsthepoleandshovelsthefilletcthreeparts.Movingthatthearmrisesandfallsandthepolefoughtstretchesoutanddrawsbackandshovelingfightingmovesallwithmovingbackandforthtypetwoeffecthydrauliccylinderscontrol.Inordertosuittheneedsofvariousdifferenceconstructionschoolassignments,thehydraulicpressureexcavatorcanbejoinedinmarriageloadingmanykindsofworkdevices,ifexcavatingandmanykindsofschoolassignmentmachinesandtoolssuchasliftingjob,loading,leveling,clampandpushessoilandshockhammeretc.Turningroundandwalksthedeviceistheorganismofhydraulicpressureexcavator,uppersettinguppower-ondeviceandtransmissionsystemofturntable.Theengineisthepowersupplyofhydraulicpressureexcavator,andadoptsdieseloilwillalsocanmodifytheelectromotorintheconvenientplacemostly.Thehydraulicdrivesystembywayofthehydraulicpumpwiththeenginethemotive-1-forcetransmissiontohydraulicpressuremotorandhydrauliccylinderetcactuator,thepromotionworkdevicemoves,thusaccomplishesthevariousschoolassignments.TakemorePV-200'smouldhydraulicpressureexcavatorsofuseinbuildingsiteastheexample.Thismachineadoptsthetypetheopeningcenterloadofadvancedversiontobepassedfeelingsystem(OLSS).Thissystemiswithobliqueofcontroltypeobliquethemethodofangle(exportvolumeofflow)variableplungerpump,andreducedthepowerdeliveryofengine,thusreducestheoilconsumptionburnt,andisonekindofsavingenergymouldsystem.Thecharacteristicofthiskindofhydraulicsystemis:thefixedtorqueiscontrolled,anditisunchangeabletokeepthehydraulicpumpdrivetorque,andyearabsolutelycontrolcanreducetheoff-loadinglossofschoolassignmenttime;Oilcapacityiscontrolled,andtheexportvolumeofflowofhydraulicpumpinthetimeofcanreducingneutralgearandfinecontrolreducesthepowerloss.Thehistoryofthefirsthandexcavatorwaspublisheduptonowtohavemorethan130years,andwentthroughfromthesteamdrivefilltoturnroundthatthemachineryturnsroundthedevelopingthecoursestepbystepofthecompleteautomatichydraulicpressureexcavatorofexcavatorandapplicationmechanicalandelectricalliquidintegrationtechnologytopowerdriveandtheinternal-combustionenginedriveinthetime.Theapplicationowingtothehydraulictechniquehadtojoininmarriageonthetractorloadinghydraulicpressuretoanti-thetypehangingwhichshoveledmachineryinthe1940’s,anddevelopingoutthepullingtypeattheinitialstageofinthe1950’swithmiddleperiodinsuccession,toturnroundthefullhydraulicpressureofhydraulicpressureexcavatorandcaterpillartreadtypeentirelymechanical.Initialstagethetrialhydraulicpressureexcavatoristhehydraulictechniquethatadoptsplaneandmachinetool,lackingthehydraulicpressurecomponentthatissuitableinthemechanicalvariousoperatingmodes,itisstableinadequatelytomakethequality,andnecessaryisnotcompletelyyet.Frominthe1960’s,thehydraulicpressureexcavatorisenteredthepopularizationandinvigorousdevelopmentstage,andmechanicalmanufacturingplantandthebreedofeachcountryincreasesveryfast,andtheoutputisrapidlyincreased.83%ofthemechanicalgrossoutputwasoccupiedtohydraulicpressureexcavatoroutput,andiscloseto100%atpresent1968-1970certainperiod.20thcentury80~90'ssmallmechanicaldeviceinconstructionandsooninmunicipalengineering,transportation,pipelinehasdisplayedabiggersuperiorityandcanrapidly-2-develop.Thesmallexcavatorforsavedthemanpower,thephysicalresourceintheseprojectsmakesthesmallexcavatormainlytouseinthecitytheconstructionconstructionandgenerallyleftabiggercontribution,graduallybecameinthecityconstructiontohavetherepresentativeconstructionmachinery.Thesmallexcavatordevelopmentmainlyreliesontheurbanconstructiondevelopment,becausecitytransformation,constructionconstructionmore,therequestconstructiontimeshort,theconstructionmachineryaffectssmall,safe,thelowpollution,theradiusofgyrationtotheenvironmentissmall,isadvantageousfortransportsaswellashaswiththecitysceneryappearancecoordinationoutwardappearance,thesmallexcavatorhassatisfiedthecityeachkindofworkrequest,canmaximumlimitdisplayitsproductivityinthecitynarrowworkingspace,thereforehastheuniquesuperiority.1.ThedevelopmentofsmallexcavatorsThesmallexcavatormainlyusesinthecitytheconstructionconstructionandthegeneralhousingrepairsandmaintainsandsoonthework,therequesthasthegoodoperatingperformanceandtherotationperformance.Initialsmallexcavatorbytiretypeprimarily,becausethetiretypewalksthenaturalinthesoftgroundandthepassingdifference,afterwardsgraduallybythemarchingsubstitution,andinmovedthearmstrutorganizationplacetoincreasetherotationorganizationabout,enabledtheentireworkequipmenttherelativeorganismtocarryonswings,completedthetrenchsidewallexcavationrenovationworkbehind,butthiskindofsmallexcavatorexcavationscopewassmall,cannotrealizethematerial.Hereafter,thesmallexcavatorincreasedupsidehasrotatedtheorganization,hassolvedbehindthemetialandsoontheproblem,enhancedtheexcavatoroperatingperformance,formedthesmallexcavatorthebasicstructure.Afterwards,thesmallexcavatorintheradiusofgyration,behindthefieldofvision,movedaspectandsoonarmelevationangle,machinecapabilityhasthefurtherimprovement,developsforthepresentstandardtype.2.TechnicalprogressesSmallexcavatorworkingconditionsmajorityofincity,inordertopreventwalkswhendamagestheroadsurface,startsfromthe80'stousetherubbercaterpillarband,andgraduallyobtainsthepopularization.Arubbercaterpillarbandheavywheeliswhentheinternalironcircuitboardthemovement,thehardcircuitboardjointplaceandtheheavywheelcontactfallstotheground,becomeswalksthedestructionroadsurfacemainreason.Beforeusesthewidthshapeironcircuitboard,arubbercaterpillarbandheavywheeldiameterisbigger,thereforewhenapproachestheground,thisslitchangesinabigway,createsthecaterpillar-3-bandtotheroadsurfacedestruction.Thesupersmallexcavatoruseandthebeforesameheavywheel,onlywasthehardcircuitboardwhichinthecaterpillarbandusedchangesnarrowly,thereforewhencontactedthegroundtheslitchangesslightly,reducedtothedamageofground.Rearareathesmallrotationexcavatorrotationrearpartsizeisextremelysmall,inordertoguaranteetheexcavatorworkthestability,musthavetheenoughcounterweight,andindoesnotincreasethemechanicalweightunderthepremise,usesincreasesthecaterpillarbandlengthandwidensthechassisandsoontheeffectivemethod.But,thechassiswidthistransportedthetruckwidththelimit,forsolvesthisproblem,hasusedViCTASinthesupersmallexcavator(Vio-CrawlerTechnologybyAdvancedStability)thetechnology.3.ComfortablenessThesmallexcavatormajorityofsealscab,hasnotrainedwhenthechairfrequentlydripswetbytherainseeps.Inordertosolvethisproblem,theusesurfaceandtheinteriorgatherapeacefulfatrubberbodytomanufacturehasnotsewntheseamthechair,cannotagainfromsewtheseamplacedestruction,thedurabilityalsocanenhance,becomesthecompletewaterproofingchair.(1)Thesmallexcavatorhasthewidespreadserviceablesmallexcavatorvolumesmall,mobileisflexible,extremelyissuitableforworkandsooncitieseachkindofpipelining,foundationconstruction,publicutilitiesaswellashouseservice.Thesmallexcavatorcompactvolume,thespecialdesignenableitstocarryontheworkintheenvironmentwhichthelarge-scaleexcavatorisunabletoconstruct.(2)Thesmallexcavatorhasthemulti-purposesmallexcavatortruemeritisithasmulti-purpose.Thesmallexcavatorcaninstallmanyauxiliaryworksmachinesandtools,liketheinstallmentbrokenhammer,thehydraulicpressurepliersuseinthelightweightdemolisionwork,installsaclamptouseintoeliminatethework,installsthedrum,theplateusesinthetrenchtofillinburiesthecompaction,theinstallmentturnsonlathedigsdrillsusesinthedrillhole,thelifthookusesintohoistupheavyitemandsoon.(3)Thesmallexcavatorisadvantageousforthetransportationandoneofshiftworklocationsmallhydraulicpressureexcavatormarketrapidexpansionreasonsshouldbelongtoitssizeandtheweight.Thesmallexcavationfunctionconvenientlyshiftsineachjoblocation,thesmallexcavatordoesnotneedthelarge-scaletrailerperhapstheheavy-dutytruckcarriesonthetransportation,thesmalltransportmeansmaydeliver.Likethisnotonlycanfacilitate-4-thetransportation,butalsomaygreatlyreducethemachinethecartageexpense.(4)Smallexcavatorbrightworkcharacteristic:Therearpartradiusofturnforthezerodesign,causesthesmallexcavatornottoneedintheworkspacelimitedenvironmentmeanindustrytimeexcavatoroperatortoconsiderthejoblocationis,whetherthusenabletheoperatortohavetheobstacletohindertheexcavatortherotationtosufficewhollyabsorbedtothescoopoperation,thishasalsopreventedaroundthejoblocationthebuildingaswellastheexcavatorowndamage.Thesmallexcavatorpriceischeap,thecostrecyclesquickly.Slightlydigstakethe6tlevelastheexample,American,theEuropeandatebrandmachinepriceabout400,000Yuan,SouthKorea'smachinepriceabout320,000Yuan,thedomesticallyproducedmachinepriceis30~320,000Yuansomebrandsislower;Butthe20tlevelcenterdigsthepricein70~1millionYuan.Thehigherinvestmentrepaymentratecausesthesmallexcavatordeeplythegeneralcentersmallearthworkconstructiontocontractowner'swelcome.Thesmallexcavatortechnologicaldevelopmentcompliedwiththeglobaldiversificationjoblocationthedemand,hasexperiencedmorethan30yearshistorysuccessionalvariationprocess,passesthroughtheunceasingimprovementconsummation,inaspectandsoontechnicalperformance,jobfunction,workefficiency,security,environmentalprotection,energyconservationandmaintenancemaintenancehadthelargescaleenhancement,hasformedthequiteconsistenttechnicalstandardandtheworkstandard.Mainlymanifestsinfollowingseveralaspects:(1)Thetaillessrotationandmovesthearmdeflectiontechnologytotakeslightlydigsthebasicconcepttomovethearmdeflectionandthetaillessrotationfunctionlaterperiodpromotesinthe1990sfacetheworldmarket.Movesthearmdeflectionintheorganismfrontpart,butdoesnothavetheorganizationtobeabletorealizeislocatednearbythelowerpartofwallthedirectexcavationworktohavefrequentlytomovethefuselage.Thetaillessrotationstructureapplication,causesitwhentheneckoflandworkdoesnotneedtoworrytherearpartthecollision.Thetaillessrotationstructuraldesigndifficultyliesinrotatesintheplatformthegeneralarrangement,thedynamicsystemthermalequilibriumsolutionaswellastheentiremachinestablesolution.Butmovesthearmdeflectionorganizationthedesigndifficultytolieinanarticulationpositionthedeterminationandthehingebodymanufacturetechnology.(2)Newhydrauliccontroltechnology-5-Thenewhydrauliccontroltechnologyshouldhavetheworkefficiencyhigh,theserviceabilityisgood,hasthegoodefficiency,maycarryonthehighefficiency,thepowerfulwork.Thenewfluidenvironmentcompatibilitypressesthesystemnottoshoulderthesizetheinfluence,completelyneedstheoilofthehydraulicpressuresystem,thecurrentcapacityaccordingtothecontrolhandlescopedistributionpoint,definitelymaydefertooperator'sintentionwitheasetocompletethework.Atthesametime,becausetheengineloadissmallmayavoidthecurrentcapacitythesenselessloss,canrealizeslightlymovestheoperationandthecompoundoperation.Thenewhydrauliccontroltechnologyapplicationalsocanincreasethedynamicoutput,enhancestheworkspeed,reducesthefuelconsumption.(3)SecurityperformanceHasthestrictlegalruleintheEuropeanmarketandtheNorthAmericamarkettothesecurity,theequipmentsecurityperformancecangivetheoperatortoprovidetherelievedworktheenvironment,enhancesoperator'ssecurity.ThesmallexcavatorsecurityperformancemainlymanifestsinthecabROPS/FOPSdesignbelow,shouldsatisfytheperformancerequirementinthecabexperiment:②Maysatisfymustanti-load;Mainlymanifestsinthepower,thelowoilconsumption,cleanlydischargestheengineintheapplication.ThenewengineshouldsatisfytheAmericanEPATier2standardandtheEuropeanEUstandard,willcausetheenvironmentalpollutionthecompoundtodischargethecontrolinthethreshold.Thenewenginesimultaneouslyreducedthevibrationandthenoise,isbeneficialtotheenvironmentalprotectionandoperator'shealth.(5)Man-machineprojecttechnologyThecabconformstotheman-machineengineeringprinciple,internalspacious,fieldofvisionopen,modellingartistic,theeaseofoperation,reduceseffortthemeasuringappliancedemonstrationdirect-viewing,isaccurate,canprovideonekindofcomfortableoperatingenvironmenttothepilot,fullyreducespilot'sweariness.(6)ServicesthemaintenancetechnologyMaintainsfromthecurrentmaintenancetotheregularinspectionservice,thesimplificationoperationisextremelyessential,canenhancethemachinethereliability,makesthemachinethroughouttomaintainthegoodcondition.Mustcausethedailyinspectionside,-6-therealizationnottoneedwiththeaidofthetoolassoonastotouchthetypeoperation.Maintenancerepairthenquicklydndsimplely,butfastcarriesontheinternalsparepartandthesysteminspectionandtheservice.Moreover,inthedesignmustfullyconsiderpreventsthemachinetheaccidentdamage.Suchasthecowling,theguardplateguardsagainstthecollisionstructuraldesign;Movesthearmhydrauliccylinderguardplatedesign;Fueloiltankdraw-offvalve;Theindependencebulldozestheboardhydraulicpressurehosedesign;Waterproofingelectricsystemdesign;Intheworkinstallmenthosesetsatthedesign;Xframeandhalfwayupthemountainsidecaterpillarbanddesign;Theenginemachineoilfilterelementreplacementtimelengthens;Hasforerunnersystemwhichthepipelinefilters;Dualspatiallyfiltersstructuredesignandsoon.5ConclusionsSociety'sdevelopmenthasamoretremendousinfluencetothesmallexcavator,atpresenttheoverseassmallexcavatorhadthesuitabledevelopment,likeCarterotherforces,companyandsoonHitachi,smallpine,Mitsubishi,thesmallexcavatorproducthasformedtheseries,andinunceasinglycarriesonthedevelopment,theexpandeduse,theincreaseappendixtype.Thedomesticsmallexcavatordevelopmenthasalsoobtainedthecertainresult,butallneedsfurthertoimproveandtheconsummationinthetechnologyandtheproduction.-7-國(guó)內(nèi)外小型挖掘機(jī)發(fā)展綜述一、液壓挖掘機(jī)簡(jiǎn)介液壓挖掘機(jī)是由發(fā)動(dòng)機(jī)、液壓系統(tǒng)、工作裝置、行走裝置和電氣控制等部分組成。液壓系統(tǒng)由液壓泵、控制閥、液壓缸、液壓馬達(dá)、管路、油箱等組成。電氣控制系統(tǒng)包括監(jiān)控盤、發(fā)動(dòng)機(jī)控制系統(tǒng)、泵控制系統(tǒng)、各類傳感器、電磁閥等。液壓挖掘機(jī)一般由輪胎式、步履式、全液壓、半液壓、全回轉(zhuǎn)、非全回轉(zhuǎn)、通用型、專用型、鉸接式、伸縮臂式等多種類型。工作裝置是直接完成挖掘任務(wù)的裝置。它由動(dòng)臂、斗桿、鏟斗等三部分鉸接而成。作業(yè)的需要,液壓挖掘機(jī)可以配裝多種工作裝置,如挖掘、起重、裝載、平整、夾鉗、推土、沖擊錘等多種作業(yè)機(jī)具。是液壓挖掘機(jī)的動(dòng)力源,大多采用柴油要在方便的場(chǎng)地,也可改用電動(dòng)機(jī)。動(dòng)工作裝置動(dòng)作,從而完成各種作業(yè)。以工地使用較多的PV-200型液壓挖掘機(jī)為例。該機(jī)采用改進(jìn)型的開式中心OLSS斜盤角(輸出流量)的方法,減少了發(fā)動(dòng)機(jī)的功率輸出,從而減少燃油消耗,是一種節(jié)能型系統(tǒng)。這種液壓系統(tǒng)的特點(diǎn)是:定轉(zhuǎn)矩控制,能維持液壓泵驅(qū)動(dòng)轉(zhuǎn)矩不變,載斷控流量,減少功率損失。-8-逐步發(fā)展過(guò)程。由于液壓技術(shù)的應(yīng)用,20世紀(jì)40年代有了在拖拉機(jī)上配裝液壓反鏟的懸掛式機(jī)械,20世紀(jì)50年代初期和中期相繼研制出拖式全回轉(zhuǎn)液壓挖掘機(jī)和履帶式全20世紀(jì)60年代起,液壓挖1968-1970年間,液壓挖掘機(jī)產(chǎn)量已占機(jī)械總產(chǎn)量的83%,目前已接近100%。二、小型挖掘機(jī)的發(fā)展及其趨勢(shì)20世紀(jì)80~90年代小型挖掘機(jī)在市政工程、交通、管道等施工中發(fā)揮了較大優(yōu)勢(shì)并得以迅速發(fā)展。它在城市的土建施工工程中為節(jié)省人力、物力出了較大貢獻(xiàn),逐步成為城市施工中具有代表性的施工機(jī)械。小型挖掘機(jī)的發(fā)展主要依賴于城市建設(shè)的發(fā)展,由于城市的改造、建設(shè)施工較多,要求施工時(shí)間短、施工機(jī)械對(duì)周圍環(huán)境影響小、安全、低污染、回轉(zhuǎn)半徑小、便于運(yùn)輸以及具有與城市景色相協(xié)調(diào)的外觀,小型挖掘機(jī)滿足了城市各種作業(yè)要求,在城市狹窄的工作空間內(nèi)能夠最大限度地發(fā)揮其生產(chǎn)能力,因此具有獨(dú)特的優(yōu)越性。1.小型挖掘機(jī)的發(fā)展小型挖掘機(jī)在城市中主要用于土建施工及一般住宅修整等工作,要求具有良好工作性能和回轉(zhuǎn)性能。最初的小型挖掘機(jī)以輪胎式為主,由于輪胎式在軟地面的行走性和通過(guò)性差,后來(lái)逐漸被履帶式替代,并在動(dòng)臂支撐機(jī)構(gòu)處增加了回轉(zhuǎn)機(jī)構(gòu),使整個(gè)工作裝置能相對(duì)機(jī)體進(jìn)行左右擺動(dòng),以完成溝道側(cè)壁挖掘整修工作,但這種小型挖掘機(jī)挖掘范圍小、不能實(shí)現(xiàn)后部卸料。此后,小型挖掘機(jī)增加了上部回轉(zhuǎn)機(jī)構(gòu),解決了后部卸料等問題,提高了挖掘機(jī)的工作性能,形成小型挖掘機(jī)的基本結(jié)構(gòu)。后來(lái),小型挖掘機(jī)在回轉(zhuǎn)半徑、后部視野、動(dòng)臂仰角、機(jī)械性能等方面得到進(jìn)一步改善,發(fā)展為現(xiàn)在的標(biāo)準(zhǔn)型。2.技術(shù)的進(jìn)步小型挖掘機(jī)工作環(huán)境大部分在城市,為了防止行走時(shí)損壞路面,從80年代開始使用橡膠履帶,,鐵芯板接縫處與支重輪接觸落地時(shí),成為行走破壞路面的主要原因。以前使用寬形鐵芯板,橡膠履帶的支重輪直徑較大,因此在接近地面時(shí),這個(gè)縫隙變大,-9-掘機(jī)使用與以前相同的支重輪,只是履帶內(nèi)使用的鐵芯板變窄,因此在接觸地面時(shí)縫隙變后方小回轉(zhuǎn)型挖掘機(jī)的回轉(zhuǎn)尾部尺寸非常小,為了確保挖掘機(jī)工作的穩(wěn)定性,必須有足夠的
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