液壓支架自動(dòng)化成功的途徑外文文獻(xiàn)翻譯、中英文翻譯、外文翻譯

ThepathtoSuccessfulRoofSupportAutomation1ABSTRACTThefirsthydraulicroofsupportswereinstalledundergroundin1950sandeversincethatengineeringdevelopmentshaveimprovedthesupportsinmanydifferentways.However,advancesinthreemainareas,theroofsupportmechanicaldesign,hydraulicengineeringandelectronicshaveultimatelyledtothepointwhere,35yearsafterthatinstallation,automationhasbeenachievedandisnowcommonplace.Thehistoryofroofsupportautomationhasinvolvedthecontinualintegrationofhightechnologyengineering.Therearefurtherpossibilitiesforthefuturewhichcombinetogivesomeideaofthelikelihoodofthereultimatelybeingacompletelymanlessface.2INTRODUCTIONAround35yearsago,adevelopmenttookplacewithintheminingindustrythat,withhindsight,pavedthewayforthisindustrytochangefrombeingahighlylabourintensiveone,totheindustryoftoday.Thisdevelopmentwastheintroductionofthehydraulicroofsupport.Thefirstgenerationsupport,withitssimplistichydraulictapcontrols,wasaquantumleapinitstime,contributingtoimprovedsafetyoftheworkplaceandimprovedproductivity.Relativetotheuseofpropsandbars,theactivityofsupportingtheroofhadactuallybeen“automated”,andthereafterthechallengeforgreaterdegreesofautomationwaslaidfirmlyatthefeetoftheroofsupportdesigners.Consequently,manyimprovementsweremadeinthefieldsofstructuralandenvironmentalmechanicalengineeringandthedevelopmentofhydraulicsystemswhichwouldoperatereliablyusingwater-basedfluids.Thisimprovedengineering,coupledwiththedevelopmentknowledgeoftheminingengineersoftheeffectsofandloadpatternsinducedfromdifferenttypesofstrata,ledtothedevelopmentofcompetentmechanicalstructures.EarlyattemptstouseelectronicstocontrolthesesupportsweremadewithinBritishCoalandthefirstROLEsystem(RemoteOperatedLongwallFace)wasinstalledin1967.Unfortunatelytherewassimplynottheefficientcyineithertheroofsupportortheelectronicstechnologyofthedaytoprovidetherequiredsuccess.Thedevelopmentoftheshieldsupportcoincidedwiththeavailabilitiesofimprovedvalvematerialsandfluidsandalsoof“chip”electronictechnology.Itwasthemarriageofthesedevelopmentsthatledtoautomationsuccess,withtheshieldsupportprovidingtheidealenvironmentfortheapplicationofelectro-hydraulics.Today,enhancementsofthesetechnologies,alongwiththeintroductionofthemicroprocessor,providestheindustrywithextremelyreliable,flexibleandefficientsystems.Theautomatedroofsupportsarenolongeradesignerdreambutareatrue,every-dayworkingreality.Theancessorofthemodernroofsupportisthewoodenpitprop.Therefore,when,inthemid1950s,thefirst“roofsupports”weredesigned,theseweremerelyextensionsoftheknowntechnology.Inthefirstchocksupports,hydraulicjacksof2inchborewereheldverticalinasimpleboxframeformingthebaseandthecanopywasapairofsimpleI-beamgirders.Ahydraulicsjackmountedinthebaseprovidedforconveyorpushandroofsupportadvance.Clearlytheusersoftodaycaneasilyunderstandthemultitudeofshortcomings-someofwhichstillhadnotbeendesignedoutandsome,itmaybeargued,whichwereinadvertentlydesignedin.Nonetheless,relativetotheoldmethodsofpitpropsandbars,thefirstgenerationsupportwasatremendousforwardstepandmaderealcontributionstosafetyandproductivity.Fromthisfirstdevelopmentquiterapidprogresswasmade.Amajorrequirementwastoprovideasafertravelwaythroughthefaceforthefaceoperatorandthiswassolvedbyaddingone,oralternativelytwo,forwardlegswiththeirownroofcanopiesandfloorbasestothefourlegunit..Thisalsogreatlyimprovedtheroofcontrolcharacteristics.Bytheearly1960s,thesearticulatedsupports,withloadcarryingcapacitiesofupto180tonnes,wereusingsubstantiallyimprovedfabricationsandhydraulics.althoughtheirapplicationundergroundwasstillrestrictedtoseamheightsof1.5metres.Theworldwideexpansionoflongwallmining.coupledwithaneedtoextracthigherseamranges,ledtoarequirementforsupportsofhigherloadcarryingcapacities.Thustherigidbasechockwasintroducedin1968.Thissecondgenerationsupportprovidedforsupportratingsofupto720tonnescanseamextractionofthreemetres.Theshieldsupportemergedinthe1970sandtheearly2legcaliperdesignswereextensivelyusedinGermanyandintroducedintotheUSAandSouthAfrica.Theseshieldswerepoorinefficiencyandsufferedfromveryhightoeloadings.Theintroductionoflemniscatedesignswasmadeinthelate1970s.Shieldsupportsrequiredfundamentalchangesindesignphilosophyinthatthemechanicallinkageresistedstratalateralforcesinadditiontoverticalforces.Thisprovidedforafarmoreefficientandreliablesupportanditsrobustnessallowedforthesuccessfulapplicationofthelongwallsysteminstrataconditionswhichhadpreviouslybeenimpossible,forexample,theextremelyheavyconditionsofNewSouthWales,AustraliaandsomeofthemorefriableroofconditionsintheUnitedKingdom.Theefficiencyofthemodernshieldsupportprovidesthesuitableenvironmentforsuccessfulapplicationofautomation.ThepreferredconfigurationofshieldsupportsintheUSAisthe2legdesign,andthisdesignhasbeenthemajorplatformformanyoftheautomationdevelopmentsthatarecurrentlyavailable.TheconfigurationisbeingintroducedintotheUKandAustralianmarketandwillcontinuetobeintheforefrontofroofsupportandautomationdevelopmentforalongtimeintothefuture.3ROOFSUPPORTHYDRAULICSUPTOTHE1980sRoofsupportsystemsuselargevolumesoffluidbothtofillupthesystemandthentocompensateforleakageandotherfluidlosses.Thiseconomicfactorcoupledtootherssuchasfirehazardandtransportationlogisticsoflargevolumesofliquidsledalmostimmediatelytoroofsupporthydraulicsystemsbecomingwater-based.Itisafactthattheuseofwater-basedhydraulicshasbeenanareaofengineeringinwhichtheroofsupportmanufactureshavetrulyledthetechnologyandeventoday,veryfewmanufacturesofindustrialhydraulicequipmentincludeproductssuitableforusewithwater-basedfluidswithintheirportfolio.Theearliestroofsupportsystemsusedsealandvalvetechnologythatwasnotatallsophisticated.Simpletapvalvesandleathersealswithstringpackingswerethebestthatwasavailableforworkingattherelativelyhighpressureof7MPa.Engineerssoonrealizedthatspecialvalvegearwouldbeneededinordertocaterforeffectslikeconvergence,toensurethatlegsremainedcompetentlysetandtosimplifythemethodsofoperation.Sonon-returnvalves,bleedvalvesandselectorvalvessoonappearedinordertosafeguardtheworkplaceandequipmentandtomakelifeeasierfortheoperators.Allthewhile,valvesealingtechnologieswereslowlyimprovingasmanufacturersdevelopeddifferentvalveseatformsusingvarioushardandsoftmaterials.Legandramsealtechnologyalsochangedrapidly,withmanufacturessoonusingrubbersofvarioushardnessesandrubber-fabriccomposites.The“dreamcometrue”ofthemaintenanceengineerwastheeventualdevelopmentofthequick-releaseorstaplelockhosefittingwhichverysoonalmostuniversallyreplacedthethreadedconnection.Fluidtechnologywasanareathatalsocreatedproblems.Inthebeginningtherewasemulsifyingoilandwater.Butitwassurelyneverconceivedthatthewaterusedformixingcouldhavesomanypotentiallycatastrophiceffects.Toomuchhardness,toolittlehardness,metalsaltsandbacteriaplayedhavocwithwater/oilemulsions,resultinginseparation,scumming,filterblockageandultimatelycreatingsevereproblemswithintheequipment..Abnormallyhighlevelsoffluidpercentageintheemulsioncausedseparationandscumming,lowstrengthscausedseverecorrosionwithinvalvegearandcylinders.FluidsgraduallyimprovedandtherecognitionofBritishCoalSpec.18andSpec.19watersbroughtaboutthedevelopmentoffluidsspecifictothehardnessesofwaterswithwhichtheyweretobemixed.Fluidcontaminationbyparticlesofdirthasalwaysbeenaproblemunderground.Itisagainonlyrelativelyrecentlythatbreakthroughshavebeenmade.Itusedtobethecasethatfilterblockageandbypasswasacceptedandtheresultwasbypassingvalvesandextremewearonpumps,unloadingvalvesetc.Valvegeardevelopmentcontinueddownthepathtoautomationintheearly1970swiththeintroductionofsequence,strikerandlatchingvalveswhichformedthebasisofhydrauliclogicappliedtoroofsupports.Thusitwasattemptedtocreatesequencedoperationsfromasimplecontrolvalveinitiationmovementbytheoperator.Singlesupports,somequitecomplexinvolvingspragsandforepoles,werecontrolledthus.Thetechniqueevenextendedtohydraulicbatchorbankcontrol.Inthisdesign,anumberofsupportsweresequencedbyhydrauliclogicfromaninitiationsignalgivenononeofthem.IndeedthefirstGullickforerunnerofthemodernelectrohydraulicsystemsused,ineachbank,aninitiatorchock,whichhousedtheelectronicsandsolenoidvalves,and3slavechocks.Inthosedayshydrauliclogicwaspreferredbecausetheelectronicswas“toocomplicated”.Infactthehydraulicswastoocomplicatedandthevalvegearwasusually,bynecessity,buriedbeneathamassofhosespaghettiandwasanightmareforthemaintenancefitterparticularlyifthehydraulicfluidwaspoorlymaintained.Theseearlyfailuresofhydraulicandelectrohydraulicautomationledtothedemiseofautomationintheearly1970s,andmoresimplersystemswererevertedto.Howeverdevelopmentcontinuedandmostimportantofall,theshieldsupportwasbeginningtoemerge.4ROOFSUPPORTELECTRONICSUPTOTHE1980sAsearlyas1964itwasrealizedthatelectronicsheldthekeytotheautomation.AboltattemptwasmadewithinBritishCoaltoproduceafullyautomatedface-includingmachineinitiation-undertheROLFproject.Thesystemsfailednotintheirendeavourbutbecausetheequipmentandtheroofsupportsofthedayweresimplynotsuitable.However,theROLFprojectprovidedthatonedayautomationshouldwork.Alulloccurreduntilthelate1970swheretheheavydutyprogrammeofBritishCoalonceagainawakenedthoughtsofautomation.GullichDobsondecidedthatanhydrauliclogicinitiatorsystemwouldstandachanceofsuccess,buthadrecognizedtheearliershortcomingsoftheinflexible“hardlogic”usedwithROLF.Therefore,thedecisiontousemicroprocessorforcontrolwithintheon-facecontrolboxes,andtheuseofaGateEndcomputerwasawiseone,butnotwithoutriskgiventherelativenewnessofmicroprocessortechnology.AutosequentialsoftwareresidedintheGateEndComputerandcommandswerecommunicatedtotheintelligentOFUstoactivatesolenoidvalves,insequencetopilotoperatetheroofsupports.ThreeGullickelectro-hydraulicfaceswereinstalledduringthelate1970sandthedevelopmentculminatedinasystem,nolongerusingasmuchhydraulicbanklogic,whichcontrolledroofsupportandconveyor,andalsoextensionbarsandsprages.Anotherdevelopmentwascoalfacealignment,whereconveyorstraightnessandwebdepthwerecontrolledbymicroprocessorbasedelectronicsonthesupports,withacomputerinthegate-endandalinktothesurface.Twoinstallationsweremanufacturedandalthoughtheysufferedfromvariousproblemsincludingingressofwaterintotherampositionsensors,theyprovedtheprinciplesofcoalfacealignmentandsurfacetransmission.5ROOFSUPPORTCONTROLSYSTEMSUPTOTHEPRESENTDAYTheearlyattemptsatautomationhadprovedthattheultimategoalwouldonedaybeachieved.Certainconclusionshadbeenreached.Theshieldsupportprovidedtherightenvironmentfortheapplicationofautomation.Valvegearwouldneedtobedesignedthatwasreliableathighpressures,toleranttocontaminationandcapableofhignflows.Legsandramswouldneedtobecapableofhighloads,rapidoperationandsuitableforheavyyieldingconditionswhereapplicable.Themicroprocessorwasasensibleelectronicapproach,andthatdemandsforhighspeedandmultipleoperationscouldexposethelimitsofintrinsicallysafesystemswhichusedsolenoidvalvesandsimplerhard-wiredlogicelectronics.Gullickbeganisdevelopmentprogrammeforthenewgenerationbyaddressingconclusions2.Italreadyhadshields,microprocessorandanewgenerationoflegsandramswasalreadybeingdeveloped.Valvegearcapableofworkingatgreaterthan30MPa,yetlowcurrent,wasthekeyingredientandin1984Gullickintroducedthemotorizedvalve.This10to20milliamppilotvalvecouldworkquitehappilyat35MPaandstillprovideflowscomparabletoasolenoidvalveconsumingperhaps120MA.Reliabilitywasbetterthanasolenoidvalveduetothesmoothoperationandhighforcesavailable.Themotorizedvalveallowedthemultipleoperationlimitationsofintrinsicallysafepowersuppliestobeovercome,allowingatleastfivetimesthenumberofvalvestobesimultaneouslyoperated,comparedwithprevioussolenoidsystems.ThusElectroflexwaslaunchedandthemotorizedvalvewascoupledtoamicroprocessorcontrolsystemembodyingthelatestCMOSlowpowerchipsandtechniques.ThisresultedinasysteminwhicheachsupportwasequippedwithanOFU,avalvepackandidenticalsimplehydraulics.TheGateEndComputerwasusedasthemediumforcontrollingthrautomationprocess.ThefirstinstallationofElectroflexin1984,atSherwoodColliery,BritishCoal,wasagreatsuccessandreliableGateEndComputercontrolwasachieved,includingcontrolofspragsandforepoles.In1985thesystemsawexportuse,withinstallationsinAustraliaandtheUSA.AlthoughenvironmentproblemsbedeviledtheUSAattempt,theAustralianinstallationworkedextremelywellandisstillindailyuseatBaalBone.Theenvironmentalproblemswereprincipallythoseassociatedwithhosingdownandhighhumidity.Oncerecognized,theywereputrightandinstallationsweresuccessfullyinstalledupto1988.WestCliffwasretro-fittedwithElectroflexin1988.Meanwhile,thefastspeedsofElectroflexroofsupportsweredictatingdevelopmentsintheareaofsealdesign.Highspeedoftenmeansheating,andwherethismightbecoupledwithalowerlubricitysemisyntheticorsyntheticfluid,thenthiscouldbeevenmoreproblematicandsoanewgenerationofsealdesignswascreated.Wherehighstressedcouldoccur,sealalternativestothetraditionalrubberandrubber/fabricweredeveloped.Plasticswereusedandthesearenowthenormforsuchheavydutyuses.In1988,itwasobvioustoGullickthatpush-button,batch,sequentialoperationswerethenormandthatmachineinitiation-firstattemptedwithROLFwasstillrequired.Mostpreviousattemptshademployedodometersystems,withpulsesordatafeddowatheshearertrailingcable,totheroofsupportcontrolsystem.However,unreliabilityandtheneedtointerfacetonumeroustypesofshearersimposedenormousdifficultieswiththisapproach.Gullickdecidedthatinfraredwasthepathtotake,anddevelopedasystemwiththefollowingmainattributes:1.Abroad,powerfulinfraredbeamcapableofpunchingthroughdust.2.Acodedinfraredtransmissiontoensurethatthesystemwasnotactivatedbycaplampsorlumimaires.3.Software,whichcouldtolerate,andbeprogrammableto,theoccasionalloss-of-signal.Thissystemwasasuccessandledtoimmediatecustomerbenefitsintermsofincreasedproductionandreducedmanpower.BecausetheGullickElectroflexsystemwasmicroprocessorbasedthroughout,itwaseasytoextendtheflexibilityofthesystem,bothmachineandman-initiated,tocaterforthemultitudeofcustomerrequeststhatfollowed,Customerswhosawthesuccessfulpotentialoftheearlysoftwareprogrammesdevelopedthesystemproactively,alongsidethesofewareteamofGullicktoprovidethefollowingfacilities:RetriesAntirelay-barpinbreakageFaceendsequencesOnfaceselectionofoutmodeDualmachinesequenceTheElectroflexsystemsoftodayareversatileandreliable.Machineinitiationisoftenspecified,andthemostrecentretro-fitofsuchequipmentatWestCliff,forexample,hasresultedinthefaceproducingrecordtonnagesundermachineinitiationcontrol.Thecurrentsystemstillusesthemotorizedvalveandotherbasicphilosophiesgoingbackdirectlytothe1984systematSherwood,andindirectlytotheearliestmicroprocessorsystemsfromthelate1970s.Motorisedvalves,alongwiththemainflowvalves,havebeenminiaturizedandimprovedandformtheMonoblocseriesofvalvegear.Electronicequipmentusesnewerchipsbutstillembodiesthebasiccircuitbuildingblocksandsoftwarebuiltupthroughoutatrackrecordof15yearsuseofon-facemicroprocessors.Aswellascontrol,monitoringoflegpressurescanbeprovidedandevenfacealignmentisavailable(thoughnotcurrentlypopularduetoimprovementsinramsystemefficiency),therebyfullycompletingacirclefirstembarkeduponin1978.SothedreamsandobjectivesofthoseengineerswhofirstconceivedROLFinthelate1960s–automation,machineinitiation,manlessoperation-areachievedtoday.Butwhatofthefuture?6ROOFSUPPORTAUTOMATIONINTHEFUTUREThereareseveraldevelopmentswhicharecurrentlypoisedtotakeroofsupportautomationintoanewgenerationwhereintegrationwithothersystemsonthelongwallwillbecomecommonplace.Roofsupportsystemsthemselveswillbecomemoreautomated,withsoftwareandhardwaredevelopingtomakethesystemsmoreintelligentandtherebycapableofdealingunaidedwithmoremarginalconditionsandintrinsicminingproblemssuchasroofcavities.Already,forexample,systemsforcontrolling4legsupports,providingcanopybalancingusingtiltsensorstolimitthepenetrationoftherearofthesupportintocavities,havebeendeveloped.Programmingdevelopmentsandnewsensortechnologywillenabletheroofsupportsystemstocontinuetobeenhancedtotakecareofthemselves,and‘expert’systemprogramming,wherethesystemlearnsfromitsownmistakes,isonthehorizon.Howevertheroofsupportsystemisnolongertheonly‘smart’systemonthelongwall.Shearers,AFCsandswitchgearcontrolandenvironmentalmonitoringequipmentallhavebuilt-inintelligence.Asneedsdictate,automationinthefuturewillconnectthesevariousintelligentsystemstogetherinorderthatinformationcanbetransferredbetweenthesystems,tothebenefitofall.Variouscoaloperatorsthroughouttheworldarenowtakingthislocalintegrationapproach,andthecommonobjectiveistoimprovereliabilityandproductivityoftheequipment,whilepermittingeasiermanagementofmaintenancetasks.Inthemediumtermitseemslikelythattheseparatesubsystemsmaythemselvesbecomeintegratedandbecomeasingleunit.Modernmicroprocessorandprogrammingtechnologyisalreadyatthepointwherethatistechnicallyfeasibleanditisonlyaquestionof‘howlong’andnot’if’.Whentheintegrationprocessisdevelopedtothefullandeachsubsystemofthefaceisprogrammedbyan‘expert’system,theremayfinallybeanopportunitytoinstallthefirstfullymanlessface.Untilthattimeitisdifficulttoseeanymajorreductionsinmanninglevelsbeyondwhatisachievabletodaywithmachineinitiationandroboticshearers.7CONCLUSIONThepathtoroofsupportautomationhasbeentroddenandasuccessfuloutcomefinallyarrivedat.Manyfactorshavecontributedanditisindeedacredittothemanyengineers,designersanduserswhohavebeeninvolvedinthesubjectthatthedreamsof35yearsagohavebeenachieved.Asthecoalindustrystepsforwardintoaneweraofenergycompetitiveness,theroleofautomationwillbecomeincreasinglyimportantasaprimarymeanstowardshigherproductivity.Thereseems,atpresent,stilltobealongpathofopportunityaheadforroofsupportautomation.

中文譯文液壓支架自動(dòng)化成功的途徑1.摘要第一架液壓頂板支護(hù)在20世紀(jì)50年代內(nèi)安裝在了地下，并且自那以后隨著機(jī)械工程的發(fā)展已經(jīng)從許多方面完善了支架。然而，頂板支護(hù)機(jī)械設(shè)計(jì)、水力工程學(xué)和電子學(xué)這三個(gè)主要領(lǐng)域的進(jìn)步最終在支架運(yùn)用35年后實(shí)現(xiàn)了自動(dòng)化，并且已經(jīng)普及當(dāng)前。頂板支護(hù)自動(dòng)化的歷史介入了高技術(shù)工程學(xué)的連續(xù)綜合化。將來有進(jìn)一步的可能性是它們結(jié)合在一起為最終實(shí)現(xiàn)無人操作的新面貌提供一個(gè)可能的思想。2.介紹大約35年前，一個(gè)變化發(fā)生在了煤炭行業(yè)，事后看來，它為煤炭產(chǎn)業(yè)從高勞動(dòng)力密集場(chǎng)所演變成今天鋪平了道路。這個(gè)變化便是液壓頂板支護(hù)的引入。第一代支架，采用簡(jiǎn)單的液壓閥控制，一開始就突飛猛進(jìn)的發(fā)展，為改善工作場(chǎng)所的安全性和提高生產(chǎn)力作出了貢獻(xiàn)。相對(duì)支柱和氣壓計(jì)的用途，支護(hù)頂板的活動(dòng)“實(shí)際上被自動(dòng)化”，以后為獲得更大自由度的挑戰(zhàn)就要落在頂板支護(hù)設(shè)計(jì)師的肩膀上了。結(jié)果，許多改進(jìn)發(fā)生在了結(jié)構(gòu)和環(huán)境機(jī)械工程以及使用水為基礎(chǔ)的流體可靠操作的液壓系統(tǒng)的發(fā)展領(lǐng)域。這被改進(jìn)的工程學(xué)，加上采礦工程師們總結(jié)出不同類型巖石層適合什么樣的支架安裝型式的經(jīng)驗(yàn)，知識(shí)在不斷豐富，機(jī)械結(jié)構(gòu)的強(qiáng)度也在提高。早在1967年，英國(guó)煤礦就試驗(yàn)使用電子控制支架，并且第一套遙控長(zhǎng)壁采煤系統(tǒng)被用于地下。不幸地是，無論在頂板支護(hù)還是今天的電子技術(shù)，不只是效率就能提供必需的成功。掩護(hù)式支架的發(fā)展與改善后的閥材料和流體的可及性以及“芯片”電子技術(shù)相符了。那是隨著掩護(hù)式支架為電液壓系統(tǒng)的應(yīng)用提供了理想的環(huán)境后，促使自動(dòng)化成功的發(fā)展因素的結(jié)合。今天，這些技術(shù)的進(jìn)步，與微處理器的引入一起，為煤炭行業(yè)提供了極端可靠，靈活和高效率的系統(tǒng)。自動(dòng)化的頂板支護(hù)不再是設(shè)計(jì)師的夢(mèng)想，而是真實(shí)的，每天運(yùn)作的現(xiàn)實(shí)?，F(xiàn)代頂板支護(hù)的前身是木制的坑柱。所以，在20世紀(jì)50年代中期，第一架支架被設(shè)計(jì)出來時(shí)，這些僅僅是已知的技術(shù)的延伸。在第一架垛式支架中，帶有英寸長(zhǎng)鏜孔的液壓油缸垂直放于箱體內(nèi)作為基底，頂梁是一對(duì)工字梁。固定在底部的液壓缸起到為刮板輸送機(jī)提供傳動(dòng)力和驅(qū)動(dòng)支架上升的作用。今天的用戶能很容易知道垛式支架的很多缺陷，這些缺陷有的還沒設(shè)計(jì)出來，有的可能被忽略掉了。盡管如此，相對(duì)坑柱和氣壓計(jì)的老方法，第一代支架向前邁了很大的一步，在安全和生產(chǎn)率方面做了真正的貢獻(xiàn)。在第一次發(fā)展后，進(jìn)步就更快了。一個(gè)主要的需求是為地面操作人員提供更安全的運(yùn)輸方式。這就需要根據(jù)它們的支架頂梁和底版增加前柱或換成四柱。這會(huì)大大改善頂梁的控制性能。到20世紀(jì)60年代早期，這些相互聯(lián)系的支架裝載容量達(dá)到了180噸，被直接用于改進(jìn)制造和液壓技術(shù)，即便在地下使用仍被限制在1.5米的煤層厚度。隨著對(duì)獲取更高煤層的需求，長(zhǎng)壁采煤也遍及了全球。這也進(jìn)一步導(dǎo)致對(duì)支架的裝載輸送容積的要求更高了。緊接著在1968年引進(jìn)了底版牢固的垛式支架。第二代支架能滿足720噸的容量，而且可以在3米厚的煤層中工作。掩護(hù)式支架是在20世紀(jì)70年代涌現(xiàn)的，最早的兩柱式掩護(hù)梁設(shè)計(jì)在德國(guó)被廣泛使用，并被引進(jìn)到美國(guó)和南非。掩護(hù)式支架的效率低，但能承受很高的載荷。雙紐線設(shè)計(jì)是在20世紀(jì)70年代后期引進(jìn)的。掩護(hù)式支架要求在設(shè)計(jì)原理上從根本改變。機(jī)械連接除抵抗垂直方向變形外，還有巖層側(cè)面的力。它提供了更有效可靠的支架，它的粗壯使它成功地應(yīng)用在煤層中的長(zhǎng)壁系統(tǒng)中，這在以前是不可能的。例如，在新南威爾士和澳大利亞那極端困難的條件下以及在英國(guó)更易破裂的頂板下。現(xiàn)代掩護(hù)式支架的效率為自動(dòng)化的成功應(yīng)用提供了合適的環(huán)境。在美國(guó)更側(cè)重于結(jié)構(gòu)的掩護(hù)式支架是兩柱設(shè)計(jì)，這種設(shè)計(jì)是許多自動(dòng)化發(fā)展的主要平臺(tái)，也是目前可使用的。這種結(jié)構(gòu)正被引入英國(guó)和澳大利亞，而且在未來很長(zhǎng)一段時(shí)間內(nèi)將處于頂梁支護(hù)自動(dòng)化發(fā)展的最前線。3.20世紀(jì)80年代后的液壓支架頂梁支護(hù)系統(tǒng)使用大量的液體裝滿整個(gè)系統(tǒng)，以彌補(bǔ)泄露量和其他流動(dòng)損耗。此經(jīng)濟(jì)因素和其他如火災(zāi)和運(yùn)輸大量液體方面的問題帶來了以水為基礎(chǔ)的液壓支護(hù)系統(tǒng)。以水為基礎(chǔ)的液壓技術(shù)的應(yīng)用已經(jīng)在工程學(xué)上占據(jù)了一個(gè)領(lǐng)域，頂梁支護(hù)生產(chǎn)者們真正利用了這項(xiàng)技術(shù)，甚至現(xiàn)在，有很少的工業(yè)液壓技術(shù)設(shè)施生產(chǎn)者的文件夾里包含可與流體配套使用的產(chǎn)品。最早期的頂板支護(hù)系統(tǒng)使用的是根本不復(fù)雜的密封和閥門技術(shù)。簡(jiǎn)單的開關(guān)閥和帶有一系列包裝的皮帶密封是最好的，可在比7Mpa高的壓力下工作。工程師們很快意識(shí)到為了發(fā)揮集中力的作用，需要特殊的閥齒輪確保立柱有足夠的支撐度，簡(jiǎn)化操作方法。之后為了保障工作環(huán)境和設(shè)備的安全性，方便工作人員操作，單向閥、排出閥和選擇活門便應(yīng)運(yùn)而生了。一直以來，制造商使用軟硬不同的各種各樣的材料，開發(fā)了不同的閥門座形式閥門密封技術(shù)在慢慢地得到改善。隨著生產(chǎn)廠家逐漸使用各種硬度的橡膠和橡膠織品綜合的橡膠材料時(shí)，支柱和密封技術(shù)就迅速地發(fā)生了變化。堅(jiān)持不懈的工程師們夢(mèng)想成真是最終的制動(dòng)楔軟管的發(fā)展，它們很快幾乎普遍替代了螺紋聯(lián)接。流體技術(shù)也是制造問題的一個(gè)領(lǐng)域。開始時(shí)有乳化油和水。但從來沒有想過的是，混合使用的水可能有許多潛在的災(zāi)難性影響。堅(jiān)硬太大、太小、金屬鹽和細(xì)菌破壞了水或油形成的乳化液。造成分離物，熔渣、過濾器堵塞。最終使設(shè)備出現(xiàn)了嚴(yán)重的問題。例外地，在乳化液里含有高水平可變的流體百分比導(dǎo)致了分離物和熔渣，低強(qiáng)度在閥門齒輪和圓筒之內(nèi)導(dǎo)致了嚴(yán)重腐蝕。流體逐漸改善,英國(guó)煤礦對(duì)Spec.18和Spec.19水的公認(rèn)讓流體的發(fā)展明確達(dá)到了混合水的硬度。微量的垃圾制造的流體污染在地下依然是一個(gè)問題。相對(duì)而言，最近又有了新的突破。過濾器堵塞，旁路被接受曾經(jīng)是實(shí)際情形。結(jié)果是旁通閥，在泵上的極端磨損，卸荷閥等。閥門齒輪在20世紀(jì)70年代初期朝自動(dòng)化的方向發(fā)展。伴隨著一系列的壓力閥和銷閥的引入，它們構(gòu)成了應(yīng)用于3頂板支護(hù)的液壓邏輯機(jī)構(gòu)的基本元件。然后它試圖由操作員從簡(jiǎn)單的控制閥啟蒙運(yùn)動(dòng)著手創(chuàng)造程序化的操作。單體支護(hù)，一些包括支柱和前部的某些相當(dāng)復(fù)雜體因被控制。技術(shù)延伸到一批或邊坡控制。此設(shè)計(jì)中，一定數(shù)量的支護(hù)由液壓邏輯從他們中的任意一個(gè)傳遞出的啟蒙信號(hào)程序化?，F(xiàn)代電液壓機(jī)構(gòu)的第一個(gè)Gullick先行者在每一個(gè)邊緣的確使用了，一個(gè)主動(dòng)制動(dòng)器，帶動(dòng)電子和電磁閥和3個(gè)從動(dòng)制動(dòng)器。在過去，因?yàn)殡娮蛹夹g(shù)太復(fù)雜，液壓邏輯元件更受歡迎。事實(shí)上液壓學(xué)是比較復(fù)雜的，閥門齒輪通常在必要的時(shí)候被掩藏在橡皮絕緣管下，特別是如果液壓機(jī)構(gòu)中的流體不足被維護(hù)了，對(duì)維護(hù)鉗工來說是個(gè)惡夢(mèng)。液壓和電液壓自動(dòng)化的這些早期的失敗導(dǎo)致20世紀(jì)70年代初期自動(dòng)化陷入了困境，而且更簡(jiǎn)單的系統(tǒng)被恢復(fù)了。然而發(fā)展仍在繼續(xù)。最重要的是，掩護(hù)式支架開始涌現(xiàn)。4.80年代的頂板支護(hù)電子學(xué)早在1964年，人們就意識(shí)到電力對(duì)自動(dòng)化起著舉足輕重的作用。在英國(guó)煤礦螺栓企圖被用來生產(chǎn)一個(gè)完全自動(dòng)化的面孔包括在ROLF項(xiàng)目之下的創(chuàng)始機(jī)械。整個(gè)系統(tǒng)癱瘓了，不是他們付出的努力少，而是由于那時(shí)的設(shè)備和頂板支護(hù)太過簡(jiǎn)單而不適宜。然而，ROLF這個(gè)項(xiàng)目設(shè)想某天自動(dòng)化能實(shí)現(xiàn)。短暫的平息直到20世紀(jì)70年代晚期，英國(guó)煤礦沉重的責(zé)任項(xiàng)目再次喚醒了自動(dòng)化的想法。GullichDobson判斷一個(gè)液壓初始系統(tǒng)意味著成