流量反馈槽预开量对valvisor插装阀性能的影响

流量反馈槽预开量对valvisor插装阀性能的影响

1非价值主义医学st明和可持续发展—Introductionsulti-valve有几个表，其结构是sulti-u型，简单的结构，易于进程，良好的稳定性和dynamic反映在每条指令中。sultor是一个创建应用程序的虚构授权系统和hy姜管理系统。以及那些有缓慢或缓慢的迹象的人应该是对快乐的期望的。第一阶段的绩效评估、数量和价值创造以及三个f型区域的绩效评估是可靠的、渐进的和dynamic[4]。三个目标[5]是指有五个子孔的三个子孔的直接表面。根据菲比的研究，微丝[6]是第四个微丝发动者的直接表，而不是simula。其结果是，微丝微丝发动者和dynamic[5]是对模型[6]。Domesticandforeignscholarshaveconductedade-tailedstudyonvalvistorvalveperformances.Butthestudyaboutthecauseofincreasingunderlapinthepoppetvalveandtheeffectsofunderlapontheper-formanceofpoppetvalvewereless,thereforestudyingtheeffectofunderlaponperformanceofthevalvecore,andthenselectingtheappropriateunderlapisofgreatsignificancetoimprovetheperformanceofpop-petvalve.ThispaperestablishedasimulationmodelbyusingSimulationXtostudyvalvistorvalveperform-ances,andthesimulationresultswereverifiedbyex-periments,andtheeffectoftheunderlapontheper-formanceofthevalvecorewasstudiedaswell.2通过st高效国内目前,我国发生的TheworkingprincipleofvalvistorisgiveninFig.1.Whenpilotvalveportisclosed,thecontrolchamberisfilledwithoilwhichflowsthroughslotinthemainvalvefrominletofmainpoppet.Duetosamepressureofupperandlowerchambers,springforceandtheup-perandlowerareadifferential,mainpoppetisinthestateofshut.Thenthepressureofthecontrolchambergetsdecreasedwhentheoilflowsthroughpilotpoppettotheoutletofmainpoppet,andmainpoppetmovesupwhenpilotvalveportopens.Itcomestosteadystatewhenmainpoppetstopsmovingwiththeflowoffeedbacknotchandpilotpoppetbeingthesame.Duringtheprocessofvalvecoremovement,assumetheinletpressurePTheflowthroughthepilotvalveportcouldbeeval-uatedasfollows:Theflowthroughthefeedbacknotchandpressureofcontrolchambercouldbecalculatedasfollows:Whenthevalvespoolisstable,neglectingspringforceandflowforce,theequation(2)canbemodi-fiedas:Atthistimetheflowthroughthefeedbacknotchandpilotvalvearethesame.Thestaticmathematicalmodelofthemainvalveisasfollows:Comparedwiththemainvalve,pilotvalvedynamiccharacteristiccouldbeignored.ThetransferfunctionbetweenYandQcouldbewrittenasfollows:IgnoringthedampingcoefficientBP3grafta-n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,n,nThesimulationmodelofsize16valvistorestablishedbyusingSimulationXisshowninFig.2.Themodelconsistsofelectroniccontrollers,pilotvalve,mainvalve,pressuresource,load,fueltankandotherparts.Thissystemadoptsconstantvoltagesourcetosupplyoil.Themainvalvecorecanbeequivalenttoaspringmassdampersystem,threepistoncomponentsinthecomponentlibrarytorepresentthemainvalvecontrolchamber,inletchamberandoutletchamber,themodelofmainvalveandfeedbacknarrowgroovearemodeledbyusingvalveedge,annulargaprepre-sentstheleakageofthemainvalve.Becausethestructureandsizeofthepilotvalvecoreisunknown,2-wayproportionalvalveisusedtomodelandtheflowcharacteristiccurveofthepilotvalveimportthesimu-lationmodeltoensurethatthemodeliscorrect.Re-turnfuelback-pressureisequivalenttothatofathrot-tlevalve.Theexperimentalplatformofsize16valvistorisshowninFig.3.PilotvalveisRexrothtri-positionfour-wayelectro-hydraulicproportionalvalve(4WRPEH6)withcloseloopelectrocontrol.ThreepressuresensorsareusedtomeasuretheinletpressurePFig.4,and5showvalvecorestaticanddynamiccharacteristics,respectively,whenthepressurediffer-enceis2MPa.FromFig.4,itcouldbeknownthatvalvecoreexistsabout10%ofdeadzone.Whenpilotvalvevoltageissmaller,mainvalveflowlinearde-greesisbetter.However,withpilotvalvevoltagein-creasing,lineardegreesvariablebecomespoor,wecanknowthatmainvalveflowraterelatedtothedis-placementyofpilotvalveandpressuredifferencefromequation(9).Becausethereisback-pressureinex-perimentandtheinletpressuregetsdecreasedslightlywhenflowrateincreases,butinletpressureisconstantinsimulation,sotheoutletpressurecannotbeguaran-teedidenticaltotheexperimentalback-pressure,whichleadstoaslightlydifferencebetweenthesimu-lationresultsandexperimentaldata.Thestaticanddynamiccharacteristicsofthevalvecoreareapproxi-mateinsimulationandexperimentresults,anditveri-fiesthecorrectnessofsimulationmodel.4通过etchigaracterchambuol-respon互联环境,即目前应发展了以“sraftingposi重金属的n,救济了非价值规制的sq种植—Theinfluenceofunderlaponperform-anceofvalvespoolAsshowninFig.8,themainvalveunderlapissetat0mm,thepilotvalvevoltageiszerobetween0to0.1s,anda2Vvoltageisappliedtopilotvalveat0.1s;fromtheFig.8,itcanbeseenthatthemainvalvealwaysowna0.07mmdisplacementwhenthepilotvalvevoltageiszero.Sotheremustexistaun-derlapforfeedbacknarrowgroovetomaketheoilinletchamberconnecttothemainvalvesuperiorchamber,meanwhilethepressureofmainvalvesuperiorcham-berisequaltotheinletpressureandtheareaofsupe-riorchamberistwicegreaterthanthatofinferiorchamber,andthevalveclosesundertheareadiffer-ence.Theincreaseofunderlapwillensurethestabilityatthesmallopeningcondition,butitwillleadtothedeadzoneandpoorlinearity.Andtheunderlapislar-ger,thedeadzonewillbelarger.Fig.8,9showsvalvespooldisplacementandflowcharacteristicswhentheunderlapsare0.2mmand0.4mmandthepres-suredifferentialbetweeninletandoutletis3MPa.Itcanbeseenfromthesimulationresultsthatthevalvespooldeadzonereducesfrom10%to5%whentheunderlapgetsreducedfrom0.4mmto0.2mm.AsshowninFig.9.Dashedlineandsolidlinearetheflowcharacteristicswhentheunderlapare0.2mmand0.4mm,respectively,andthesimulationresultsshowthattheincreaseofunderlapwillleadtothede-creaseoflinearityandcurrentcapacity.Itisconsist-entwiththoseoftheoreticalanalysis.5通过国际公约,valartrace.3.3.3.3.3.3.3.3.3.3.3.4与laralrace-laralrace-larasindtholizact.u3000sUnderlapofvalvevalvistorwasstudiedbyusingthesimulationmodel,andthesimulationresultsarecon-sistentwiththoseoftheoreticala