項目3 任務(wù) 4 疊加閥的認(rèn)知

疊加閥的認(rèn)知KnowledgeaboutSandwichValve任務(wù)4Task4任務(wù)描述TaskDescription1了解常見疊加閥的基本工作原理及符號，進一步熟悉疊加閥的種類，熟悉常見疊加閥在不同場合的應(yīng)用。Understandthebasicworkingprinciplesandsymbolsofcommonsandwichvalves,beacquaintedwiththetypesofsandwichvalves,andbefamiliarwiththeapplicationsofsandwichvalvesindifferentscenarios.疊加式液壓閥簡稱疊加閥，其閥體本身既是元件，又是具有油路通道的連接體，閥體的上、下兩面做成連接面。選擇同一通徑系列的疊加閥疊合在一起用螺栓緊固，即可組成所需的液壓傳動系統(tǒng)。疊加閥按功用的不同，分為壓力控制閥、流量控制閥和方向控制閥三類，其中方向控制閥僅有單向閥類，主換向閥不屬于疊加閥。Sandwichvalveisshortforhydraulicsandwichvalve.Itsvalvebodyisacomponentandalsoaconnectingbodywithfluidpath.Theupperandlowersidesofthevalvebodyaremadeasconnectingsurfaces.Bystackingsandwichvalvesofthesamediameterseriesandfasteningthemwithbolts,adesiredhydraulictransmissionsystemcanbeformed.Sandwichvalvescanbeclassifiedbythefunctionintothreetypes:pressurecontrolvalve,flowcontrolvalve,anddirectionalcontrolvalve.Directionalcontrolvalvesofthistypeincludecheckvalvesonly,andmainreversingvalvesarenotsandwichvalves.疊加閥的結(jié)構(gòu)和工作原理Structureandworkingprincipleofsandwichvalve2圖3-4-1（a）所示為先導(dǎo)型疊加式溢流閥的外形。其結(jié)構(gòu)原理如圖3-4-1（b）所示，它由先導(dǎo)閥和主閥兩部分組成，先導(dǎo)閥為錐閥，主閥相當(dāng)于錐閥式的單向閥。其工作原理是：壓力油由P口進人主閥芯6右端的e腔，并經(jīng)閥芯上阻尼孔d流至主閥芯左端b腔，再經(jīng)小孔a作用于錐閥芯3上。當(dāng)系統(tǒng)壓力低于溢流閥調(diào)定壓力時，錐閥關(guān)閉，主閥也關(guān)閉，閥不溢流；當(dāng)系統(tǒng)壓力達(dá)到溢流閥的調(diào)定壓力時，錐閥芯3打開，b腔的油液經(jīng)錐閥口及孔c由油口T流回油箱，主閥芯右腔的油經(jīng)阻尼孔d向左流動，于是使主閥芯的兩端油液產(chǎn)生壓力差。Figure3-4-1(a)showstheappearanceofapilot-operatedsandwichoverflowvalve.ItsstructureprincipleisshowninFigure3-4-1(b).Itiscomposedofaconicalpilotvalveandamainvalvethatisequivalenttoaconicalcheckvalve.Itsworkingprincipleisasfollows:PressurefluidflowsfromportPintothechambereattherightendofthemainvalveelement(6),andflowsthroughthedampingholedonthevalveelementintothechamberbattheleftendofthemainvalveelement,andactsontheconicalvalveelement(3)viathesmallholea.Whenthesystempressureislowerthanthesetpressureoftheoverflowvalve,theconicalvalveisclosed,themainvalveisalsoclosed,andthevalvedoesnotallowoverflow.Whenthesystempressurereachesthesetpressureoftheoverflowvalve,theconicalvalveelement(3)opens,fluidinthechamberbflowsbacktothetankfromthefluidportTviatheconicalvalveportandtheholec,andfluidintherightchamberofthemainvalveelementflowsleftwardviathedampingholed,creatingpressuredifferencebetweenbothendsofthemainvalveelement.疊加閥的結(jié)構(gòu)和工作原理Structureandworkingprincipleofsandwichvalve2此壓力差使主閥芯克服彈簧5的壓力而左移，主閥口打開，實現(xiàn)了自油口P向油口T的溢流。調(diào)節(jié)彈簧2的預(yù)壓縮量便可調(diào)節(jié)溢流閥的調(diào)整壓力，即溢流壓力。圖3-4-1（c）所示為其圖形符號。Thispressuredifferenceallowsthemainvalveelementtoovercomethepressureexertedbythespring(5)andmoveleftward,andthemainvalveportopenstoallowoverflowfromthefluidportPtothefluidportT.Byadjustingthepre-compressionofthespring(2),theregulatingpressure(i.e.overflowpressure)oftheoverflowvalveandbeadjusted.Figure3-4-1(c)showsitsgraphicsymbol.疊加式液壓系統(tǒng)的組裝Assemblyofsandwichhydraulicsystem3疊加閥自成體系，每一種通徑系列的疊加閥，其主油路通道以及螺釘孔的大小、位置、數(shù)量都與相應(yīng)通徑的板式換向閥相同。因此，將同一通徑系列的疊加閥互相疊加，可直接連接而組成集成化液壓系統(tǒng)。Sandwichvalvecanbeself-containedsystem.Forsandwichvalvesofadiameterseries,theirmainfluidpathandthesize,positionandquantityofscrewholesarethesameasthoseoftheplatetypereversingvalveofcorrespondingdiameter.Therefore,anintegratedhydraulicsystemcanbeassembledbystackinganddirectlyconnectingsandwichvalvesofthesamediameterseries.疊加式液壓系統(tǒng)的組裝Assemblyofsandwichhydraulicsystem3圖3-4-2（a）所示為疊加式液壓裝置的外形。其結(jié)構(gòu)如圖3-4-2（b）所示，最下面的是底板，底板上有進油孔、回油孔和通向液壓執(zhí)行元件的油孔，底板上面第一個元件一般是壓力表開關(guān)，然后依次向上疊加各壓力控制閥和流量控制閥，最上層為換向閥，用螺栓將它們固成一個疊加閥組。一般一個疊加閥組控制一個執(zhí)行元件。如果液壓系統(tǒng)有幾個需要集中控制的液壓元件，則用多聯(lián)底板，并排在上面組成相應(yīng)的幾個疊加閥組。Figure3-4-2(a)showstheappearanceofasandwichhydraulicdevice.ItsstructureisshowninFigure3-4-2(b).Atitsbottomisabaseplate,whichaccommodatesfluidinlet,fluidreturnportandfluidportleadingtohydraulicactuator.Thefirstcomponentonthebaseplateisgenerallyapressuregaugeswitch,onwhichpressurecontrolvalvesandflowcontrolvalvesarestackedinorderandareversingvalveisinthetoplayer.Boltsareusedtofixthemintoasandwichvalvebank.Generally,onesandwichvalvebankcontrolsoneactuator.Ifahydraulicsystemhasseveralhydraulicactuatorsthatneedtobecontrolledinacentralizedmanner,multiplebaseplatescanbearrangedsidebysideonittoformcorrespondingsandwichvalvebanks.疊加式液壓系統(tǒng)的組裝Assemblyofsandwichhydraulicsystem3(a)RealProductPicture(b)StructurePrincipleDiagram(c)GraphicSymbol1-Pushrod2-Spring3-Conicalvalveelement4-Valveseat5-Spring6-Mainvalveelement疊加式液壓系統(tǒng)的組裝Assemblyofsandwichhydraulicsystem3Figure3-4-2SandwichHydraulicDevice(a)RealProductPicturesofTwoandThreeSandwichValveBanks(b)StructureDiagram任務(wù)實