项目6 任务 3 气动控制元件的认知

气动控制元件的认知KnowledgeaboutPneumaticControlComponents任务3Task3任务描述TaskDescription1了解常见气动控制阀的基本工作原理及符号，进一步熟悉气动控制阀的种类，熟悉常见气动控制阀在不同场合的应用。Understandthebasicworkingprinciplesandsymbolsofcommonlyseenpneumaticcontrolcomponents,beacquaintedwiththetypesofpneumaticcontrolvalves,andbefamiliarwiththeapplicationsofpneumaticcontrolvalvesindifferentscenarios.在气压传动系统中，气动控制元件是控制和调节压缩空气的压力、流量和方向的种类控制阀，其作用是保证气动执行元件（如气缸、气马达等）按设计的程序正常地进行工作。气动控制元件按功能可分为压力控制阀、流量控制阀、方向控制阀以及能实现一定逻辑功能的逻辑元件。Inapneumatictransmissionsystem,thepneumaticcontrolcomponentsrefertovariouscontrolvalvesthatcontrolandregulatethepressure,flowrateanddirectionofcompressedair,inordertoensurethatthepneumaticactuatingcomponents(e.g.,aircylinder,airmotor,etc.)workproperlyasperdesignedprograms.Pneumaticcontrolcomponentscanbeclassifiedbyfunctionintopressurecontrolvalve,flowcontrolvalve,directionalcontrolvalveandlogiccomponentscapableofrealizingcertainlogicfunctions.压力控制阀PressureControlValve2压力控制阀的作用是控制压缩空气的压力和依靠空气压力来控制执行元件的动作顺序。压力控制阀是利用压缩空气作用在阀芯上的力和弹簧力相平衡的原理来进行工作的，主要有减压阀、溢流阀和顺序阀。Pressurecontrolvalvecontrolsthepressureofcompressedair,andcontrolstheactionsequenceofactuatingcomponentsbytheairpressure.Pressurecontrolvalveworksbybalancingtheforceofcompressedairactedonvalveelementandthespringforce.Pressurecontrolvalvesmainlycomprisereliefvalve,overflowvalveandsequencevalve.压力控制阀PressureControlValve2减压阀的作用是将出口压力调节为比进口压力低的调定值，并能使输出压力保持稳定（又称为调压阀）。减压阀分为直动式和先导式两种。Reliefvalveregulatestheoutletpressuretoasetvalvelowerthantheinletpressure,andkeepstheoutputpressurestable(alsoreferredtoaspressureregulatingvalve).Reliefvalvescomprisedirect-actingtypeandpilottype.1减压阀（调压阀）ReliefValve(PressureRegulatingValve)Figure6-3-1StructureSchematic,FunctionalSymbolandRealProductPictureofQTYReliefValve压力控制阀PressureControlValve2安装减压阀时，要按气流的方向和减压阀上所示的箭头方向，依照分水滤气器-今减压阀个油雾器的安装次序进行安装。调压时应由低向高调，直至规定的调压值为止。阀不用时应把手柄放松，以免膜片经常受压变形。Thereliefvalveshallbeinstalledaspertheairflowdirectionandthearrowdirectionindicatedonthevalve,inaccordancewiththeinstallationsequenceofwater-separatinggasfilter-reliefvalveatomizedlubricator.Pressureshallberegulatedfromlowtohigh,untilthespecifiedpressureisachieved.Whenthevalveisnotused,thehandleshallbereleased,inordertopreventthemembranefromdeformationunderpressure.压力控制阀PressureControlValve2溢流阀的作用是当系统中的压力超过调定值时，使部分压缩空气从排气口溢出，并在溢流过程中保持系统中的压力基本稳定，从而起过载保护作用（又称为安全阀）。溢流阀也分为直动式和先导式两种。按其结构可分为活塞式、膜片式和球阀式等。Overflowvalvereleasesaportionofcompressedairfromtheexhaustventwhenthesystempressureexceedsthesetvalue,andkeepsthesystempressurebasicallystableduringthereliefprocess,soastorealizetheoverloadprotection(thevalveisalsoreferredtoassafetyvalve).Overflowvalvescomprisedirect-actingtypeandpilottype.Theycanbeclassifiedbystructureintopistontype,membranetypeandballtype,etc.2溢流阀

OverflowValveFigure6-3-2StructureSchematic,FunctionalSymbolandRealProductPictureofDirect-actingOverflowValve流量控制阀FlowControlValve3图6-3-3所示为快速排气阀工作原理图。进气口P进入压缩空气，并将密封活塞迅速上推，开启阀口2，同时关闭排气口O，使进气口P和工作口A相通。当P口没有压缩空气进入时，在A口和P口压差作用下，密封活塞迅速下降，关闭P口，使A口通过O口快速排气。Figure6-3-3showstheworkingprincipleofquickexhaustvalve.CompressedairentersviatheairintakePandpushesthesealedpistonupwardquicklytoopenvalveport2andcloseexhaustportOatthesametime,thustheairintakePisconnectedwiththeserviceportA.WhenthereisnocompressedairenteringviaportP,thesealedpistondropsquicklyunderthedifferentialpressurebetweenportAandportP,thusportPisclosed,andportAdischargesairquicklyviaportO.流量控制阀FlowControlValve3快速排气阀常安装在换向阀和气缸之间。表示了快速排气阀在回路中的应用。它使气缸的排气不用通过换向阀而快速排出，从而加速了气缸往复的运动速度，缩短了工作周期。Quickexhaustvalveisusuallyinstalledbetweenreversingvalveandaircylinder.Theapplicationofquickexhaustvalveincircuitisdescribed.Itenablesthecylinderexhausttobequicklydischargedwithoutpassingthroughthereversingvalve,therebyacceleratingthereciprocatingmovementspeedofaircylinderandshorteningtheworkcycle.Figure6-3-3WorkingPrinciple,FunctionalSymbolandRealProductPictureofQuickExhaustValve方向控制阀DirectionalControlValve4方向控制阀是气压传动系统中通过改变压缩空气的流动方向和气流的通断，来控制执行元件启动、停止及运动方向的气动元件。Directionalcontrolvalveisthepneumaticcomponentthatcontrolsthestart,stopandmovementdirectionofactuatingcomponentbychangingtheflowdirectionandon/offofcompressedairflowinpneumatictransmissionsystem.根据方向控制阀的功能、控制方式、结构方式、阀内气流的方向及密封形式等，可将方向控制阀分为几类。Directionalcontrolvalvescanbeclassifiedintoseveraltypesaccordingtotheirfunction,controlmode,structure,airflowdirectioninvalve,andsealform.方向控制阀DirectionalControlValve4Table6-3-1ClassificationofDirectionalControlValvesClassificationTypeByairflowdirectioninvalveCheckvalve,reversingvalveBystructureofvalveelementCheckvalve,slidevalveBysealformofvalveBysealformofvalveByworkingpositionsandwaysofvalveTwo-positionthree-way,two-positionfive-way,three-positionfive-way,etc.Two-positionthree-way,two-positionfive-way,three-positionfive-way,etc.Pneumaticcontrol,electromagneticcontrol,mechanicalcontrol,manualcontrol方向控制阀DirectionalControlValve41单向型方向控制阀One-wayDirectionalControlValve单向型方向控制阀的作用是只允许气流向一个方向流动。它包括单向阀、梭阀和快速排气阀等。One-waydirectionalcontrolvalveallowsairflowinonlyonedirection.Itincludescheckvalve,shuttlevalveandquickexhaustvalve,etc.当气流由P口进入时，气压力克服弹簧力和阀芯与阀体之间的摩擦力，使阀芯左移，阀口打开，气流正向通过。为保证气流稳定流动，P腔与A腔应保持一定的压力差，使阀芯保持开启状态。当气流反向进入A腔时，阀口关闭，气流反向不通。whenairflowentersviaportP,thepressureforceovercomesthespringforceandthefrictionforcebetweenvalveelementandvalvebodytomovethevalveelementleftward,thusthevalveportisopenedandtheairflowpassesinnormaldirection.Toensurethestableairflow,acertaindifferentialpressureshallbemaintainedbetweenchamberPandchamberA,soastokeepthevalveelementinopenstate.WhenairflowenterschamberAinreverseddirection,thevalveportisclosed,andairflowcannotpassinreverseddirection.（1）单向阀(1)CheckValve方向控制阀DirectionalControlValve4Figure6-3-4RealProductPictureandFunctionalSymbolofCheckValve方向控制阀DirectionalControlValve4（2）梭阀(2)ShuttleValve当需要两个输入口P1和P2均能与输出口A相通，而又不允许P1和P2相通时，就可以采用梭阀（或门）。当气流由P1进入时，阀芯右移，使P1与A相通，气流由A流出。与此同时，阀芯将P2通路关闭。反之，P2与A相通，P1通路关闭。若P1和P2同时进气，则哪端压力高，A就与那端相通，另一端自动关闭。whentwoinputportsP1andP2arebothrequiredtobeconnectedtooutputportA,whileportsP1andP2arenotallowedtobeconnectedtoeachother,theshuttlevalve(orgate)canbeadopted.WhenairflowentersviaP1,thevalveelementmovesrightward,thusP1isconnectedtoA,andairflowcomesoutthroughA.Atthesametime,thevalveelementclosestheP2channel.Onthecontrary,whenP2isconnectedtoA,theP1channelisclosed.IfairentersviaP1andP2atthesametime,Aisconnectedtotheendwhicheverhashigherpressure,andtheotherendisclosedautomatically.方向控制阀DirectionalControlValve4（2）梭阀(2)ShuttleValveFigure6-3-5ShuttleValve,FunctionalSymbolandRealProductPicture方向控制阀DirectionalControlValve4（3）快速排气阀(3)QuickExhaustValve当压缩空气进入进气口P时，使膜片1向下变形，打开P口与A口的通路，同时关闭排气口O。当进气口P没有压缩空气进入时，在A口与P口压差的作用下，膜片向上复位，关闭P口，使A口通过O口快速排气。whencompressedairentersairinletportP,themembrane1deformsdownward,therebyopeningthechannelbetweenportsPandAandclosingtheexhaustventO.IfthereisnocompressedairenteringtheairinletportP,themembranerestoresupwardundertheeffectofthedifferentialpressurebetweenportsAandP,therebyclosingtheportPanddischargingairquicklyviaportsAandO.方向控制阀DirectionalControlValve4（3）快速排气阀(3)QuickExhaustValveFigure6-3-6QuickExhaustValve,FunctionalSymbolandRealProductPicture2换向型方向控制阀

ReversingTypeDirectionalControlValve换向型方向控制阀的作用是通过改变气流通道来改变气流方向，进而改变执行元件的运动方向。Reversingtypedirectionalcontrolvalvechangestheairflowdirectionbychangingtheairflowchannel.气动逻辑元件PneumaticLogicComponents5气动逻辑元件种类很多，一般按下述方法分类：按工作压力分为高压型（0.2〜0.8MPa）、低压型（0.05〜0.2MPa）和微压型（0.005〜0.05MPa）；按逻辑功能分为“是门”、“非门”、“或门”、“与门”和“双稳”元件等；按结构形式有截止式、膜片式和滑阀式等。Therearemanypneumaticlogiccomponents,andtheycanbegenerallyclassifiedasfollows:high-pressuretype(0.2-0.8MPa),low-pressuretype(0.05-0.2MPa)andmicro-pressuretype(0.005-0.05MPa),byworkingpressure;"YESgate","NOTgate","ORgate","ANDgate"and"Bistable"components,bylogicfunction;cut-offtype,membranetypeandslidevalvetype,etc.,bystructure.气动逻辑元件PneumaticLogicComponents5Table6-3-2GraphicSymbolsandFunctionsofCommonlyUsedLogicComponentsTypeSymbolFunctionYESgateSamestateisalwaysmaintainedbetweeninputsignalandoutputsignalofthecomponent,i.e.,thereisnooutputifthereisnoinput,andoutputexistsonlythereisinputNOTgateOppositestateisalwaysmaintainedbetweeninputsignalandoutputsignalofthecomponent,i.e.,thereisnooutputifthereisinput,andviseversaORgateProvidedthattherearetwoinputportsandoneoutputport,thecomponentalwayshasoutputifoneortwoportshaveinput.ThetwoinputportsarenotconnectedtoeachotheratalltimesANDgateProvidedthattherearetwoinputportsandoneoutputport,theoutputexistsonlywhenbothinputportshaveinput气动逻辑元件PneumaticLogicComponents5TypeSymbolFunctionORNOTBasicdoubleinputorNOTcomponenthavingtwoinputports,wherethecomponenthasoutputonlywhenbothinputportshavenoinputsignalInhibitgateOutputofsignalbisinhibitedaslongassignalaexists;andb

outputexistsonlywhenadoesnotexistBistableWheninputsignalaexists,s1hasoutput,ands2isconnectedtoexhaustvent.Whentheasignaldisappears,componentmaintainstheoutputstateofs1.Similarly,wheninputsignalbexists,s2hasoutput,ands1isconnectedtoexhaustvent.Whenthebsignaldisappears,componentmaintainstheoutputstateofs2.Whentwoinputexistsatthesametime,thecomponentstatedependsonthestatecorrespondingtothesignalwhicheverisinputearlier气动辅助元件PneumaticAuxiliaryComponents6气动辅助元件的功用是转换信号、传递信号、保护元件、连接元件以及改善系统的工况等。它的种类很多，主要有转换器、传感器、放大器、缓冲器、消声器、真空发生器和吸盘以及气路管件等。Pneumaticauxiliarycomponentsareusedforsignalconversion,signaldelivery,elementprotection,elementconnectionandsystemworkingconditionimprovement,etc.Therearemanykindsofpneumaticauxiliarycomponents,mainlyincludingconverter,sensor,amplifier,buffer,muffler,vacuumgenerator,suctiondiscandairpipefittings,etc.气动辅助元件PneumaticAuxiliaryComponents6Table6-3-3FunctionsofCommonlyUsedPneumaticAuxiliaryComponentsTypeFunctionConverterPneumatic-hydraulicconverterConvertthepressureenergyofcompressedairintopressureenergyofoilfluid,withoutchangingthepressurevaluePneumatic-hydraulicconverterboosterConverttheenergyofcompressedairintoenergyofoilfluid,butincreasingthepressurevalue.Itisthedevicewhichconvertsthelow-pressureairintohigh-pressurefluid,andoutputsthehigh-pressurefluidtoaloadhydrauliccylinderorotherdevicetoobtainlargerdrivingforcePressurerelayItgiveselectricsignalwhentheairpressureinpneumaticsystemishigherorlowerthanthesetpressure(ordifferentialpressure).Inaddition,pneumatic-electricalconverterisalsoacomponentthatconvertspressuresignalintoelectricalsignal;anditsstructureissimilartothepressurerelay.However,itspressureisnotadjustable;itindicatesonlywhetherthereispressureornot;anditsstructuresimple气动辅助元件PneumaticAux