车辆制动装置VehicleBrakingDevice17课

车辆制动装置VehicleBrakingDevice120型控制阀MODEL120CONTROLVALVE主讲人李西安ZHENGZHOURAILWAYVOCATIONAL&TECHNICALCOLLEGESpeakerLiXi’an制动保压位BrakingPressureMaintainingPosition（五）司机施行制动管常用制动减压，当制动管减压量达到要求时，将自动制动阀手把移到保压位，制动管停止减压呈保压状态。Driverusuallyreducespressurebyapplyingthebrakespipes.Whenthebraketubepressurereductionreachestherequirements,itwillmovetheautomaticbrakevalvehandtothepressureprotectionlevelandthebraketubestoppressurereductionisinthepressureprotectionstate.制动管刚停止减压时，作用部的主活塞、节制阀和滑阀仍处于制动位，副风缸压缩空气继续向制动缸充气使其压力降低。

Whenthebrakepipejuststopsdecompression,themainpiston,controlvalveandslidevalveoftheactingpartarestillinthebrakepositionandtheauxiliaryaircylindercompressedaircontinuestoinflatethebrakecylindertoreducethepressure.当副风缸压力下降到接近制动管压力（实际上是副风缸压力稍低于制动管压力）时，主活塞在被压缩的稳定弹簧的弹力及自重作用下，主活塞带动节制阀下移6mm(滑阀不动)，至主活塞杆的上肩接触到滑阀上端面时为止，节制阀开放了滑阀背面的f1和f2孔，盖住滑阀背面的f3孔，形成了制动保压位。Whenthesecondaryaircylinderpressuredropstoclosetothebrakepipepressure(actuallythesecondaryaircylinderpressureslightlybelowthebrakepipepressure),themainpistoninthecompressionofthestablespringelasticityandweightandthemainpistondrivecontrolvalvedown6mm(slidevalve)tothemainpistonrodshouldercontacttheupperendoftheslidevalveandthecontrolvalveopenthebackoftheslideofthef1andf2holes,coverthef3holeonthebackofthespoolvalveandformthebrakepressurelevel.节制阀盖住滑阀背面的f3孔，切断了副风缸压力空气向制动缸的充气通路，副风缸停止降压，制动缸停止升压，滑阀仍处于制动位，实现制动保压作用。Thecontrolvalvecoversthef3holeonthebackoftheslidevalve,cuttingofftheairpressureofthesecondaryaircylindertothebrakecylinder.Thesecondaryaircylinderstopsthepressureandthebrakecylinderstopstheboostandtheslidevalveisstillinthebrakingpositiontorealizingthepressureprotectioneffectofthebrake.制动保压位BrakingPressureMaintainingPosition（五）图7—30120阀制动保压位紧急制动位Emergencybrakingposition（六）节制阀开放了滑阀背面的fi和f2孔。Thecontrolvalveopensthef1andf2holesonthebackofthespoolvalve.01适应机车压力保持操纵Locomotivepressuremaintenanceadaptiveoperationfi孔与滑阀底面的l3、l4孔为贯通孔，l3.l4孔在滑阀座上是封住的，节制阀开启f1孔没有什么意义。Thef3andf4holesofthef1holeandthebottomsurfaceoftheslidevalvearethroughholesandtheholel3andl4aresealedontheslidevalveseat.Itismeaninglesstoopenthef1holeofthecontrolvalve.f2孔在滑阀内与滑阀底面的眼泪孔f4相通，在制动位时，眼泪孔f4与滑阀座的制动管孔l1连通，这样就形成了：副风缸→滑阀室F1→f2孔→l1孔→制动管，即在制动保压位时，副风缸通过眼泪孔f4与制动管相通。Thef2holeisintheslidevalvewiththetearholef4atthebottomoftheslidevalve.Atthebrakeposition,thetearholef4isconnectedwiththebrakepipeholel1oftheslidingvalveseat,thusformingthef1,f2andl1holebrakepipeoftheauxiliaryaircylinder,thatis,atthebrakingPressureMaintainingPositionlevel,thesecondaryaircylindercommunicateswiththebrakepipethroughthetearholef4.这样在制动保压位，无论制动管或副风缸有轻微的压力波动，它们相互产生压力互补作用，主活塞两侧不能形成动作压力差，确保了制动机处于制动保压位。Inthisway,inthebrakepressureholdinglevel,nomatterthebrakepipeortheauxiliaryaircylinderhasslightpressurefluctuations,theyproducepressurecomplementaryeffectwitheachotherandtheactionpressuredifferencecannotbeformedonbothsidesofthemainpiston,ensuringthatthebrakeisinthebrakepressureholdinglevel.于是，当制动管轻微漏泄时，副风缸压力空气通过f4孔向制动管逆流，防止制动保压位制动机产生再制动作用；当副风缸及其管系轻微漏泄时，制动管压力空气通过f4孔向副风缸补风，保证制动机在制动保压位不发生自然缓解。Therefore,whenthebrakepipeleaksslightly,theauxiliaryaircylinderpressureairflowsagainstthebrakepipethroughthef4holetopreventthebrakepressureholdinglevelmotorfromproducingrebrakingeffect;Whentheauxiliaryaircylinderanditspipesystemleakslightly,thepressureairofthebrakepipewillreplenishtheairtotheauxiliaryaircylinderthroughthef4holetoensurethatthemotordoesnotrelievenaturallyatthebrakingPressureMaintainingPositionlevel.紧急制动位Emergencybrakingposition（六）当机车制动机使用压力保持功能时，制动管的漏泄可通过机车制动机补足，因而副风缸的漏泄导致自然缓解的可能性更大，有了眼泪孔f4后，有效地防止了自然缓解的发生。Whenthelocomotivebrakeusesthepressurekeepingfunction,theleakageofthebrakepipecanbemadeupbythelocomotivebrake,sotheleakageofthesecondaryaircylinderismorelikelytoleadtonaturalrelief.Withthetearholef4,theoccurrenceofnaturalreliefiseffectivelyprevented.02阶段制动作用Stagebrakingaction在制动管最大有效减压量范围内，反复操纵制动管减压、保压，实现制动缸反复地增压、保压的过程为阶段制动。Withintherangeofthemaximumeffectivepressurereductionofthebrakepipe,theprocessofrepeatedlyoperatingthepressureandmaintainingthepressureofthebrakecylinderarethestagebraking.阶段制动便于机车司机根据需要调整制动力，改善列车的运行品质。Stagebrakingi