機(jī)械畢業(yè)設(shè)計(jì)液壓閥外文翻譯

1、本科畢業(yè)設(shè)計(jì)（論文）外文翻譯一題目：不同類型電磁溢流插裝閥的穩(wěn)壓特性研究學(xué)院：機(jī)械工程學(xué)院專業(yè)：機(jī)械工程及自動(dòng)化班級(jí)：學(xué)號(hào)：學(xué)生姓名：指導(dǎo)老師：提交日期：2013年03月12日的穩(wěn)壓特性研究摘要：電磁溢流插裝閥廣泛應(yīng)用于高壓和溢流液壓系統(tǒng)中，其穩(wěn)壓特性直接影響液壓系統(tǒng)的動(dòng)態(tài)響應(yīng)特性，通過實(shí)驗(yàn)和模擬研究得到的電磁溢流插裝閥的穩(wěn)壓特性為其使用提供理論指導(dǎo)。關(guān)鍵詞：溢流閥插裝閥穩(wěn)壓特性1.概述電磁溢流插裝閥多和高壓泵出口，并且必須在正常、穩(wěn)定和有限壓力下工作，與此同時(shí)，它必須具有能夠快速達(dá)到系統(tǒng)的設(shè)定壓力和具有短時(shí)間內(nèi)御荷的功能。目前，在許多動(dòng)態(tài)系統(tǒng)的各種電磁溢流插閥設(shè)計(jì)中，都有縮短其調(diào)節(jié)壓力時(shí)間的

2、意向，通過實(shí)驗(yàn)和模擬研究，得到的不同類型的電磁溢流插裝閥的動(dòng)態(tài)特性，為其系統(tǒng)的設(shè)計(jì)及其最優(yōu)化提供了理論基礎(chǔ)。2.不同類型的電磁溢流插裝閥2.1完整的電磁溢流插裝閥圖1是完整的電磁溢流插裝閥的原理圖，圖2是電磁溢流插裝閥的實(shí)驗(yàn)曲線圖，其中包括排量y,輸入信號(hào)s,液控溢流閥的入口壓力PD和主閥芯的入口壓力PA。從圖2可以看出，當(dāng)電信號(hào)傳遞到電磁閥上時(shí)，該閥的閥芯在300ms后開始移動(dòng)，它就有一個(gè)確定的響應(yīng)時(shí)間。當(dāng)液壓系統(tǒng)從御荷狀態(tài)轉(zhuǎn)換到溢流狀態(tài)時(shí)，液控溢流閥的入口壓力P和主閥芯的入口壓力P急劇上升直到達(dá)到DA溢流閥的預(yù)先設(shè)定壓力。因?yàn)樽枘酭1降低壓力使得P大于P，從圖2,我們可以看到，其達(dá)到AD浙

3、江工業(yè)大學(xué)畢業(yè)設(shè)計(jì)（外文翻譯） 3,02.01.00.50,001.01.2L4L6圖2完整電磁溢流閥的穩(wěn)壓測(cè)試曲線2.2電磁換向插裝閥和溢流插裝閥的組合電磁換向插裝閥和溢流插裝閥的組合方式如圖3所示，雖然采用可能更耗能，但益處多多。例如，這樣使得系統(tǒng)的正壓力誤差和壓力波動(dòng)范圍很小；通過以上分析可知，動(dòng)態(tài)孔R(shí)1是提升先導(dǎo)級(jí)穩(wěn)定性的核心部分。先導(dǎo)閥的粘性摩擦系數(shù)非常小。一些測(cè)試臺(tái)和測(cè)試閥的主要部件排列在桌面上。測(cè)試系統(tǒng)硬件有：移動(dòng)泵，安全閥，測(cè)試閥，促動(dòng)器，壓力傳感器和相關(guān)數(shù)據(jù)采集處理設(shè)備。因?yàn)闇y(cè)試系統(tǒng)沒有負(fù)載，所以閥的流量是非常大的。因此，很難用流量計(jì)測(cè)試流量。在這個(gè)測(cè)試中，液壓促動(dòng)器的速率用

4、于計(jì)算流量?？識(shí)1的擴(kuò)大影響先導(dǎo)級(jí)的阻尼比，通過以上模擬分析，有助于先導(dǎo)級(jí)直徑的沒計(jì),又例如，這樣可以避免會(huì)影響系統(tǒng)穩(wěn)壓特性的電磁換向閥的內(nèi)部泄漏，因?yàn)殡姶艙Q向插裝閥的關(guān)閉時(shí)間很長(zhǎng)，所以系統(tǒng)壓力的上升速度很慢。為了解決這個(gè)問題，華中大學(xué)自然科技學(xué)院設(shè)計(jì)了一種加速放大器用于縮短電磁閥的轉(zhuǎn)換時(shí)間，這在一定程度上可能縮短了調(diào)節(jié)壓力的時(shí)間，但這樣縮短其轉(zhuǎn)換的時(shí)間不可避免的在御荷時(shí)造成很大的壓力波動(dòng)。相反的，當(dāng)上腔面積保持不變時(shí)下腔面積改變，曲線如圖8所示，下腔面積的改變對(duì)閥的動(dòng)態(tài)特性幾乎沒有影響，因?yàn)楫?dāng)下腔面積變大時(shí)，輸入流量沒有明顯的改變，因此，系統(tǒng)的上升時(shí)間增長(zhǎng)。這些在傳遞函數(shù)圖中能夠看出，這意味

5、著第二個(gè)第二階部分被一個(gè)比例部分替代。因?yàn)閂。與兩個(gè)面積直接成比例，所以幾乎不變大。為了得到良好的調(diào)節(jié)壓力和減壓性能，把試用電磁方向閥轉(zhuǎn)換成電液比例閥（命名為改進(jìn)的電液換向閥），如圖4所示?？焖夙憫?yīng)和使用外部先導(dǎo)控制油源的電液比例閥，不僅提升了調(diào)節(jié)壓力的速度，而且通過采用合適的閥芯能夠減少御荷的波動(dòng)。為了驗(yàn)證這一點(diǎn)，我們?cè)趯?shí)驗(yàn)臺(tái)上進(jìn)行了改進(jìn)的電液比例插裝閥的實(shí)驗(yàn)和電液換向插裝閥的實(shí)驗(yàn)，如圖5所示。I1j供油壓力供油系統(tǒng)圖3電磁換向插裝閥和溢流插裝閥的組合山供油壓力O-供油終統(tǒng)圖4改進(jìn)的電液換向插裝閥和溢流插裝閥的組合浙江工業(yè)大學(xué)畢業(yè)設(shè)計(jì)（外文翻譯）浙江工業(yè)大學(xué)畢業(yè)設(shè)計(jì)(外文翻譯) 圖5插裝閥試

6、驗(yàn)臺(tái)電液換向閥的動(dòng)態(tài)特性的實(shí)驗(yàn)結(jié)果和改進(jìn)的電液比例插裝閥的實(shí)驗(yàn)結(jié)果如圖6和圖7所示。當(dāng)輸入的是預(yù)壓力決定的最小閥比電磁鐵小。根據(jù)牛頓定律，由彈簧力和電磁力雙重作用的先導(dǎo)閥芯下降。在這個(gè)過程中，先導(dǎo)壓力油通過閥口進(jìn)入第二級(jí)閥的下腔，接著上腔的油流回油箱使第二級(jí)閥上升。當(dāng)?shù)诙?jí)閥上升時(shí)，彈簧的反饋預(yù)壓力變大，同時(shí)彈簧變大。受電磁力、反饋彈簧力和流力的作用，閥芯將會(huì)回到平衡位置。和電液換向插裝閥的測(cè)試曲線相比，改進(jìn)的電液換向插裝閥的控制腔壓力Pc平穩(wěn)無停滯的快速上升，其入口壓力P和出口壓力P的響應(yīng)時(shí)間只有30ms,這些都表明改進(jìn)電液換向插裝AB閥的關(guān)閉特性不僅取決于液流壓力，外部先導(dǎo)控制油源也起著非

7、常重要的作用，這樣才使得其時(shí)間縮短35s鐘；另外，從轉(zhuǎn)換系統(tǒng)壓力P(7.3MPa12MPa)我們可知，改進(jìn)的電液換向插裝閥和溢流插裝A閥的組合系統(tǒng)達(dá)到穩(wěn)定壓力時(shí)間比電液換向閥和大流量閥的組合系統(tǒng)達(dá)到穩(wěn)定壓力時(shí)間快700ms。圖6電磁換向閥測(cè)試曲線8右斗硯11.1tj-rQD3*丄Jl-4Q（tooO.to0J0OJS0.200250.300350.400,450,50i/a圖7改進(jìn)的電液換向插裝閥測(cè)試曲線圖8是當(dāng)主閥芯為DN80時(shí)，3種不同類型的電磁溢流插裝閥的穩(wěn)壓模擬曲線圖，從此圖中我們可知：改進(jìn)的電液換向插裝閥和溢流插裝閥的組合體的穩(wěn)壓時(shí)間（曲線1）是最短的，大概有200ms,電液換向插裝

8、閥的溢流插裝閥的組合體的穩(wěn)壓時(shí)間（曲線2）是700ms，完整的電磁溢流插裝閥達(dá)到穩(wěn)定壓力所需的時(shí)間（曲線3）大概是900ms，改進(jìn)的電液換向插裝閥和溢流插裝閥有最短的調(diào)節(jié)壓力時(shí)間和最小的壓力波動(dòng)。因此，最后的二階組件要以簡(jiǎn)化成一個(gè)比例組件。如果考慮第二閥的泄漏，圖中的整合元素可能被第一階的慣性元素替代，因?yàn)橄葘?dǎo)和第二階中的小間隙和小泄漏的影響，它的自然頻率很高，和圖4中的第一階組成相比，第一階組成也能簡(jiǎn)化成比例部分，所以整個(gè)閥的性能直接由先導(dǎo)閥決定。而電磁溢流插裝閥的穩(wěn)壓能力很差并且壓力影響很大。由于液壓的存在電磁并不完美。當(dāng)輸入電流比確定值更大時(shí)，電磁的電壓曲線成線性。沒有使用位移電子反饋，

9、主級(jí)段位移和輸入電信號(hào)的關(guān)系在機(jī)電轉(zhuǎn)化器上為線性，所以流量反饋取其線性域的最小值。而且其剛度由主級(jí)位移決定。后續(xù)控制用于主級(jí)和第二級(jí)之間，第二閥的位移幾乎與主級(jí)相等。通過對(duì)不同類型的電磁溢流插裝閥的動(dòng)態(tài)特性進(jìn)行實(shí)驗(yàn)和模擬研究，得到改進(jìn)的電液換向我裝閥和溢流插裝閥組合體的動(dòng)態(tài)特性。使用外部先導(dǎo)控制油源時(shí)的溢流插裝閥最好，這樣不僅調(diào)節(jié)壓力快，而且具有良好的穩(wěn)壓能力。圖8不同類型電磁溢流插裝閥的穩(wěn)壓模擬曲線3-結(jié)論通過對(duì)不同類型電磁溢流插裝閥的穩(wěn)壓特性的實(shí)驗(yàn)和模擬研究,得到改進(jìn)的電液換向閥和溢流插裝閥的組合體在使用先導(dǎo)控制油源時(shí)最佳的結(jié)論。這樣不僅系統(tǒng)調(diào)節(jié)壓力迅速，而且有很好的穩(wěn)壓特性Studyon

10、stabilizedpressurecharacteristicsofdifferenttypeoftheelectromagneticoverflowcartridgevalveAbstractTheelectromagneticoverflowcartridgevalvesarewidelyusedinhighpressureandlargeflowhydraulicsystems,andtheirstabilizedpressurecharacteristicsinfluencethedynamicresponsecharacteristicsofhydraulicsystemdirec

11、tly.Theresearchonstabilizedpressurecharacteristicsofdifferenttypeofelectromagneticoverflowcartridgevalvesbyexperimentandsimulationofferstheoreticalguidanceforitsuse.KeywordsOverflowvalve,Cartridgevalve,Stabilizedpressurecharacteristics1IntroductionTheelectromagneticoverflowcartridgevalveisalwaysappl

12、iedtohighpressurepumpoutlet,andithasfunctionsofregulating,stabilizingandlimitingpressure,atthesametime,itmustmeetsystemcharacteristicsofsetuppressurequickly,unloadingtimeshortlyetc.Atpresent,differentkindsofelectromagneticoverflowcartridgevalveshavecomeforthtoshortenpressuresetuptimeinmanyhydraulics

13、ystemdesigns.Byexperimentandsimulationresearch,dynamiccharacteristicsofdifferenttypeoftheelectromagneticoverflowcartridgevalvesaregiven,whichlayatheoreticalfoundationforsystemdesignandoptimization.2DifferentTypeoftheElectromagneticOverflowCartridgeValves2.1TheIntegratedElectromagneticOverflowValveFi

14、g.1istheschematicdiagramofintegratedelectromagneticoverflowcartridgevalve.Fig.2isitsexperimentcurvesincludingdisplacementy,inputsignals,theinletpressureofpilotreliefvalvePoandtheinletpressureofmainspoolPA.Fig.2showsthatwhenelectricalsignalisgiventoelectromagneticvalve,thevalvespoolbegintomoveafter30

15、0ms,ithasacertainresponsetime.Whenthehydraulicsystemconverttooverflowstatefromunloadingstate,theinletpressureofpilotreliefvalvePAandtheinletpressureofmainspoolPAAAincreasedrapidlyuntilreachingthepresettingpressureofpilotreliefvalve,andPAishigherthanPDbecauseofthepressuredropofdampR1.FromFig.2,itcanb

16、enoticedthatthestabilizedpressuresetuptime(fromsignalgiventothepressurestabilized)isaboutl000ms.Fig.11Theschematicdiagramofintegratedelectromagneticcartridgevalve0.00201.21.41,6Fig*2:Thestabilizedpressuretestcurvesofintegratedelectromagneticcartridgevalve2.2CombinationofElectromagneticDirectionalCar

17、tridgeValveandOverflowCartridgeValveAdoptingcombinationofelectromagneticdirectionalcartridgevalveandoverflowcartridgevalve,asshowninFig.3,thecostmayincreaseinthiswaybutprofitsaremore.Foronething,deviationfpressureregulationandpressurevariationrangearesmall;Fromtheaboveanalysis,itcanbeseenthatthedyna

18、micorificeR1isthekernelcomponenttoincreasethestabilityofthepilotstage.SomemajorparametersofthetestbenchandtestvalvearelistedinTable.Thetestsystemconsistsofconstantdisplacementpump,reliefvalve,testvalve,actuator,pressuresensorsandrelevantdataacquisitionandmeasuringequipments.Theflowrateofthevalveisex

19、tremelylargebecausetheloadisnotusedinthetestsystem.Therefore,itisdifficulttomeasurebyusingtheflowratemeters.Inthistest,hydraulicactuatorvelocityisadoptedtocalculatetheflowrate.Thecoefficientofviscousfrictionofthepilotvalveisverylittle,theintroducingoftheorificeR1increasesthedampingratioofthepilotsta

20、ge.Throughsimulationanalysis,forthediameterofpilotstagedesignedinthispaper,Foranotherthing,itcanavoidtheinternalleakageinpilotelectromagneticdirectionalvalvewhichmayinfluencestabilizedpressurecharacteristics.Becausetheclosingtimeofelectromagneticdirectionalcartridgevalveislong,theincreasingspeedofsy

21、stempressureisslow.Toovercomethisproblem,HuazhongUniversityofScienceandTechnologydesignedacceleratedamplifierforelectromagneticvalvetoshortenitsswitchingtime.Itmayshortenpressuresetuptimeinacertaindegree,buttheshortswitchingtimebringslargepressureimpactwhenunloadinginevitably.Togetgoodperformancebot

22、hpressuresetupandpressurerelief,changepilotStudyonstabilizedpressurecharacteristicsofdifferenttypeoftheelectromagneticoverflowcartridgevalveelectromagneticdirectionalvalveto.electro-hydraulicproportionalvalve(namedimprovedelectro-hydraulicdirectionalcartridgevalve),asshowninFig.4.Theelectro-hydrauli

23、cproportionalvalveresponsesquicklyanditadoptsexternalpilotcontroloilsource,whichnotonlyincreasepressuresetupspeed,butalsocanreduceunloadingimpactbyusingreasonablecurve.Toverifyit,theimprovedelectro-hydraulicdirectionalcartridgevalveexperimentandtheelectro-hydraulicdirectionalcartridgevalveexperiment

24、weredoneonthecartridgevalvestestbench,asshowninFig.5.Viceversa,thelowerchamberareaischangedwiththeupperchamberareakeptthesame.ThecurveisshowninFig.8.Thechangeofthelowerchamberareahaslittleinfluenceonthedynamiccharacteristicsofthevalveaswell,becausewhenthelowerchamberareaincreases,thereisnoobviouscha

25、ngeontheloadflowrate,therefore,thesystemrisetimeincreases.Thiscanbeseeninthetransferfunctiongraph,whichshowsthatthesecondsecond-ordercomponentisreplacedbyaproportionalcomponent.BecauseVoisdirectlyproportionaltothetwoareas,thegainchangeslittle.Pr山lLPffStufCOdfupptvoFig*3:Theschemaficdiagramofcombinat

26、ionofelectromagneticdirectionalcartridgevalveandoverflowcartridgevaivesviJ匚IrpPreittirtoilsypplyFig*4:TheschematicdiagramofcombinationofimprovedelectromagneticdirectionalcartridgevalveandoverflowcartridgevalveFig.6andFig.7arerespectivelyexperimentalresultsofdynamiccharacteristicsfortheelectro-hydrau

27、licdirectionalcartridgevalveandtheimprovedelectro-hydraulicdirectionalcartridgevalve.whentheinputofthesolenoidislargerthanthesmallestvalvedecidedbytheprecompressionforce,accordingtotheNewtonprinciples,thepilotspooloperatedbythesolenoidforceandthespringforcegoesdown.Inthisprocess,thepilotpressureoilc

28、omesintothelowerchamberofthesecondvalvethroughthepilotvalveport,andthentheoilintheupperchambergoesbacktotank.Sothesecondvalvegoesup.Whenthesecondvalvegoesup,thefeedbackspringscompressionbecomeslarge;thespringforcealsobecomeslargeraswell,Operatedbythesolenoidforce.springfeedbackforceandtheflowforce,t

29、hespoolwillgobacktothebalanceposition.Comparedwithtestcurvesoftheelectro-hydraulicdirectionalcartridgevalve,thecontrolchamberpressurePcofcartridgevalveoftheimprovedelectro-hydraulicdirectionalcartridgevalveincreasedrapidlyandsmoothlywithoutstagnationstage,theresponsetimeoftheinletpressurePAandoutlet

30、pressurePaofcartridgevalveisshort,thecartridgevalvespoolresponsetimeisonly30msfromdisplacementycurve,allshowthattheclosecharacteristicsoftheimprovedelectro-hydraulicdirectionalcartridgevalvenotonlydependsonspringforce,theexternalpilotcontroloilsourceplaysanimportantrole,leadingtotheclosingtimeshorte

31、n3-5times.Inaddition,itisknownfromthechangeofsystempressuren,(7.3MPa-12MPa),thestabilizedpressuretimeofcombinationoftheimprovedelectro-hydraulicdirectionalcartridgevalveandoverflowcartridgevalveis700msshorterthanthestabilizedpressuretimeofcombinationoftheelectro-hydraulicdirectionalcartridgevalveand

32、overflowcartridgevalve.Q卩，1*_I_._L*-1IL,J._i.J_b_-i.J0.00.10.2030,405tisG0.7&R0,91.0L.l1.2Fig.6：Thetestcuroftheelectromagneticdirectionalcartridgevalve101/sfig.7:ThetestcurvesoftheimprovedelectromagneticdirectionalcartridgevalveFig.8showsthatwhenthemainspoolisDN80,thestabilizedpressuresimulationcurv

33、esof3differenttypeofelectromagneticoverflowcartridgevalves.Itisknownfromthisdiagram:binationoftheimprovedelectro-hydraulicdirectionalcartridgevalveandoverflowcartridgevalve(curve1)istheshortest,about200ms,thestabilizedpressuretimeofcombinationoftheelectro-hydraulicdirectionalcartridgevalveandoverflo

34、wcartridgevalve(curve2)is700ms,thestabilizedpressuretimeoftheintegratedelectromagneticoverflowcartridgevalve(curve3)isabout900ms,combinationoftheimprovedelectro-hydraulicdirectionalcartridgevalveandoverflowcartridgevalvehavefastpressureregulationtimeandsmallpressurefluctuation,Therefore,thelastsecon

35、d-orderelectrofeedback,therelationbetweenthecomponentcanbesimplifiedtoaproportionalcomponent.Iftheleakofthesecondvalveisconsidered,theintegratingelementinFig.4willbereplacedbyafirst-orderinertiaelement.Becauseofthesmallvolumeofthechamberbetweenthepilotandsecondstageandthesmallleakcoefficient,thenaturalfrequencyofitisverylarge.Comparedwiththefirstsecond-o