道岔结构及作用StructureandFunctionof

道岔结构及作用StructureandFunctionof

RailwaySwitch天津铁道职业技术学院铁路信号基础设备维护把两条或两条以上的轨道，在平面上进行相互连接或交叉的设备称为道岔。其作用是使机车车辆由一条轨道转入或越过另一条轨道，以满足铁路运输中的各种作业需要，也是铁路信号的主要控制对象之一。道岔因其构造不同而形式多样，最常见的是普通单开道岔。高速铁路道岔转辙设备结构组成及作用StructureandFunctionofHigh-SpeedRailwaySwitchTheequipmentthatconnectsorcrossestwoormoretracksontheplaneiscalledturnout.Itsfunctionistomaketherollingstockturnintoorcrossoveranothertrackfromonetrackforvariousoperationneedsinrailroadtransportation,andisalsooneofthemaincontrolobjectsofrailroadsignal.Theturnoutisindifferentformsduetoitsstructure,andthemostcommononeisthecommonsingleopenturnout.高速铁路道岔转辙设备结构组成及作用（一）单开道岔的组成普通单开道岔有左开和右开之分，是最常见、最简单的线路连接设备。普通单开道岔的组成包括转辙器、辙叉及护轨、连接部分，如图所示。StructureandFunctionofHigh-SpeedRailwaySwitch1.CompositionofsingleturnoutThecommonsingle-openingturnoutisthemostcommonandsimplestlineconnectionequipment,withtypesofleft-openingandright-openingturnouts.Thecompositionofcommonsingle-openingturnoutincludesswitchmachine,frogandguardrail,andconnectingpart,asshowninFigure.高速铁路道岔转辙设备结构组成及作用1.转辙器由两根尖轨、两根基本轨及转辙机械组成，如图所示。尖轨是转辙器的主要部件，通过连接杆与转辙机械相连，操纵转辙机械就可变换尖轨的位置，以确定道岔的开通方向。2.辙叉及护轨包括可动心轨、翼轨及护轨。其作用是保证车轮安全通过两条钢轨的相互交叉处。可动心轨是为了防止列车经过两翼轨最窄处到辙叉心时，车轮轮缘走错辙叉轮缘槽而导致脱轨设计的，可以减轻车轮对翼轨和心轨的冲击，适应列车高速运行。如图，当尖轨开通某一方向时，活动心轨的辙叉心就与开通方向一致的翼轨密贴，与另一翼轨分开。3.连接部分包括连接转辙器和辙叉及护轨的部分。它包括直线轨和导曲线轨。由于导曲线的半径较小，又不能在导曲线上设置缓和曲线和超高，所以列车在侧向过岔时，速度要受到严格的限制。1.SwitchmachineItiscomposedoftwotonguerails,twostockrailsandswitchmechanism,asshowninFigure.Thepointedrailisthemainpartoftheswitchmachine,whichisconnectedtotheswitchmachinethroughtheconnectingrod,andthepositionofthepointedrailcanbechangedbymanipulatingtheswitchmachinetodeterminetheopeningdirectionoftheturnout.2.FrogandguardrailFrogandguardrailincludesmovablefrograil,wingrailandguardrail.Itensuresthesafetyofthewheelsthroughtheintersectionoftworails.Themovablecenterrailisdesignedtopreventderailmentcausedbythewheelflangegoingtothewrongfrogflangegroovewhenthetrainpassesthroughthenarrowestpartofthetwowingrailstothefrogcenter.Itcanreducetheimpactfromthewheeltothewingrailsandfrograil,andadapttohigh-speedtrainoperation.AsshowninFigure,whenthetonguerailisopenedtoacertaindirection,theswitchforkheartofthemovablefrograilisclosetothewingrailthatisopenedinthesamedirectionandseparatedfromtheotherwingrails.3.ConnectingpartsConnectingpartsincludepartsconnectingswitchandfrogandrailguard.Itincludesstraightrailandguidecurverail.Becausetheradiusoftheguidecurveissmall,andthetransitioncurveandultrahighcannotbesetontheguidecurve,thespeedofthetrainisstrictlylimitedwhenpassingtheturnoutlaterally.StructureandFunctionofHigh-SpeedRailwaySwitch高速铁路道岔转辙设备结构组成及作用（二）道岔号由岔心所形成的角，叫辙叉角，它有大有小。道岔号码（N）是代表道岔各部主要尺寸的。通常用辙叉角α的余切来表示。如图所示，即：N=cotα。道岔号与辙叉角α成反比关系，α角越小，N越大，导曲线半径也越大，机车车辆通过该道岔时就越平稳，允许过岔速度也就越高。所以采用大号码道岔对于列车运行是有利的。随着列车重量和速度的不断提高，应逐步采用强度更高，号码更大的道岔。铁路的主要线路上大多采用9、12、18号三个型号的道岔，其通过速度如表2.TurnoutnumberTheangleformedbytheforkiscalledfrogangle,whichcanbelargeorsmall.Theturnoutnumber(N)representsthemainsizeofeachpartoftheturnout.ItisusuallyexpressedasthecotangentofthefrogAngleα.

N=cotαStructureandFunctionofHigh-SpeedRailwaySwitch

ItcanbeseenfromtheformulathattheturnoutnumberisinverselyproportionaltothefrogAngleα.ThesmallertheαAngleis,thelargertheNis,thelargertheradiusoftheguidecurveis,themorestablethelocomotiveandvehiclewillbewhencrossingtheswitch,andthehighertheallowablecrossingspeedis.Sotheuseoflargeturnoutfortrainoperationisadvantageous.Withtheincreasingweightandspeedoftrains,higherstrengthandlargernumbersofswitchesshouldbegraduallyadopted.

MostofthemainrailwaylinesadoptthreetypesofturnoutNo.9,12and18,andtheirpassingspeedsareshowninTable高速铁路道岔转辙设备结构组成及作用（三）道岔的位置和状态由图所示，道岔有两根可以移动的尖轨，一根密贴于基本轨，另一根尖轨离开基本轨，可以同时改变两根尖轨的位置，使原来密贴的分离，而原来分离的密贴，可见道岔有两个可以改变的位置。我们通常把道岔经常所处位置叫做定位，临时根据需要改变的另一位置叫做反位。为改变道岔的两个位置，在道岔尖轨处需要安装道岔转辙设备。3.Locationandstatusofturnout

AsshowninFigure,theturnouthastwomovabletonguerails,oneiscloselyattachedtothestockrail,andtheotherisawayfromthestockrail.Thepositionofthetwotonguerailscanbechangedatthesametime,sothattheoriginaltightpasteisseparated,andtheoriginalseparatedtightpasteshowsthattheturnouthastwopositionsthatcanbechanged.Weusuallyrefertotheregularpositionoftheturnoutaspositioning,temporarychangeaccordingtotheneedofanotherpositioniscalledreverse.Tochangethetwopositionsoftheswitch,installaswitchingdeviceattheswitchrail.StructureandFunctionofHigh-SpeedRailwaySwitch高速铁路道岔转辙设备结构组成及作用（四）对向道岔和顺向道岔道岔本身并无顺向和对向之分。这只是根据列车运行方向而言的。列车迎着道岔尖轨运行时，该道岔就叫对向道岔。反之，列车顺着道岔尖轨运行时叫顺向道岔。如图所示。4.OppositeturnoutandforwardturnoutTheturnoutitselfhasnodifferencebetweenforwarddirectionandoppositedirection.Thisisonlybasedonthetrainrunningdirection.Whenthetrainrunsagainsttheswitchrail,theswitchiscalledtheoppositeswitch.Onthecontrary,whenthetrainrunsalongtheturnoutswitchrail,itiscalledaforwardturnout,asshowninFigureStructureandFunctionofHigh-SpeedRailwaySwitch高速铁路道岔转辙设备结构组成及作用（五）单动道岔和双动道岔按压一个道岔按钮（电动道岔的操纵元件），如仅能使一组道岔转换，则称该道岔为单动道岔；如果能使两组道岔同时或顺序转换，则称为双动道岔，有时也称为联动道岔，故它有三动和四动的情况。为了简化操作手续，简化联锁关系，凡是能双动的道岔必须使之双动。“双动”即意味着两组道岔可作为一个控制对象来处理。如图所示。很明显，使用双动不但手续简化，而且设备也简单了。确定为双动道岔必须符合下列条件：1.开通一条进路，要求两组道岔都必须在反位。即列车要经过这两组道岔的反位位置2.开通一条进路，要求两组道岔中的任何一组在定位，而另一组也在定位时，并且不影响平行进路。3.1/3为双动道岔，对双动道岔的基本要求是：定位时都必须转换到定位，反位时又都必须转换到反位。5Single-actingturnoutanddouble-actingturnoutPressaswitchbutton(thecontrolelementoftheelectricswitch),ifonlyagroupofswitchescanbeconverted,theswitchiscalledasingleswitch;Iftwogroupsofswitchescanbeconvertedsimultaneouslyorsequentially,itiscalledadouble-actingswitch.Double-actingturnoutisalsosometimescalledlinkageturnout,soithasthree-andfour-actingsituation.Inordertosimplifytheoperationproceduresandtheinterlockingrelationship,allturnoutsthatcanbedoubleoperatedmustbedoubleoperated"Doubleacting"meansthattwosetsofswitchescanbetreatedasonecontrolobject,asshowninFigure.Obviously,usingd