英文翻譯與英文原文

1、翻譯文獻(xiàn)：（對組合機(jī)床滑臺動態(tài)性能的調(diào)查報(bào)告）文獻(xiàn)作者：PeterDransfield,出處：PeterDransfield,HydraulicControlSystem-DesignandAnalysisofTheirDynamics,Springer-Verlag,1981中文譯文：對組合機(jī)床滑臺動態(tài)性能的調(diào)查報(bào)告【摘要】這一張紙?zhí)幚碚{(diào)查利用有束縛力的曲線圖和狀態(tài)空間分析法對組合機(jī)床滑臺的滑動影響和運(yùn)動平穩(wěn)性問題進(jìn)行分析與研究，從而建立了滑臺的液壓驅(qū)動系統(tǒng)一自調(diào)背壓調(diào)速系統(tǒng)的動態(tài)數(shù)學(xué)模型。通過計(jì)算機(jī)數(shù)字仿真系統(tǒng)，分析了滑臺產(chǎn)生滑動影響和運(yùn)動不平穩(wěn)的原因及主要影響因素。從那些中可以得出那樣的

2、結(jié)論，如果能合理地設(shè)計(jì)液壓缸和自調(diào)背壓調(diào)壓閥的結(jié)構(gòu)尺寸.本文中所使用的符號如下：s1-流源，即調(diào)速閥出口流量；sel滑臺滑動摩擦力R一滑臺等效粘性摩擦系數(shù)：滑臺與油缸的質(zhì)量自調(diào)背壓閥閥心質(zhì)量C、C2油缸無桿腔及有桿腔的液容；C2自調(diào)背壓閥彈簧柔度；叫,R2自調(diào)背壓閥阻尼孔液阻，R9自調(diào)背壓閥閥口液阻se2自調(diào)背壓閥彈簧的初始預(yù)緊力；I4,I5管路的等效液感C5、c6管路的等效液容：r5,r7-管路的等效液阻；V3,v4油缸無桿腔及有桿腔內(nèi)容積；P3,P4油缸無桿腔及有桿腔的壓力F滑臺承受負(fù)載，V滑臺運(yùn)動速度。本文采用功率鍵合圖和狀態(tài)空間分折法建立系統(tǒng)的運(yùn)動數(shù)學(xué)模型，滑臺的動態(tài)特性可以能得到顯著

3、改善。一、引言在組合機(jī)床正常工作中，滑臺運(yùn)動速度的大小和它的方向以及所承受負(fù)載的變化都將以程度不同地影響其工作性能。特別是在工進(jìn)過程中?；_上負(fù)載的突然消失引起的前進(jìn)以及負(fù)載的周期性變化而引起的運(yùn)動不平穩(wěn)性，都將影響被加工件的表面質(zhì)量，在嚴(yán)重的情況下會使刀具折斷掉。根據(jù)大連機(jī)床廠要求，作者采用有束縛力的曲線圖和狀態(tài)空間分析法建立組合機(jī)床滑臺的新型液壓驅(qū)動系統(tǒng)一自調(diào)背壓調(diào)速系統(tǒng)的動態(tài)數(shù)學(xué)模型。為了改善滑臺的動態(tài)特性，有必要去分析找出滑臺產(chǎn)生前沖和運(yùn)動不平穩(wěn)的原因以及主要的影響因素，但那必須通過計(jì)算機(jī)數(shù)字仿真和研究得出最后的結(jié)果。二、動態(tài)數(shù)學(xué)模型組合機(jī)床滑臺的液壓驅(qū)動系統(tǒng)一自調(diào)背壓調(diào)速系統(tǒng)的工作原

4、理圖如圖I所示。這個(gè)系統(tǒng)是用來完成工進(jìn)一停止一快退”的工作循環(huán)。當(dāng)滑臺在工進(jìn)時(shí)，三位四通換向閥處于圖示右位，油泵的供油壓力在濫流閥的有效作用下近似地幾乎保持恒定，該油液流經(jīng)過換向閥和調(diào)速閥后進(jìn)入油缸的無桿腔，以推動滑臺向前移動；與此同時(shí)，從油缸有桿腔排出的壓力油經(jīng)自調(diào)背壓閥和換向閥流回油箱了。在這個(gè)過程中，兩個(gè)單向閥和溢流閥的工作狀態(tài)始終都沒有任何變化。對與象組合機(jī)床滑臺的液壓驅(qū)動系統(tǒng)一自調(diào)背壓調(diào)速系統(tǒng)這樣的復(fù)雜非線性的系統(tǒng)，為了便于研究它的動態(tài)特性，建立一個(gè)僅著重考慮主要影響因素的合理簡單的動態(tài)數(shù)學(xué)模型是尤其重要的12。從理論分析和試驗(yàn)研究的列舉中可以得知：該系統(tǒng)的過程時(shí)間是遠(yuǎn)大于調(diào)速閥的過

5、程時(shí)間的，當(dāng)油缸無桿腔有效承壓面積很大時(shí)，調(diào)速閥出口流量的瞬時(shí)的超調(diào)反映為滑臺運(yùn)動速度的變化是很小的2。為了更加拓寬和深入研究系統(tǒng)的動態(tài)特性，使研究工作能在微型計(jì)算機(jī)上有效地進(jìn)行，本文章對原模型2做進(jìn)一步簡化處理，假定調(diào)速閥在系統(tǒng)的整個(gè)通過過程中輸出時(shí)候恒定的流量，這被看作其為流源。這樣，系統(tǒng)的動態(tài)模型的結(jié)構(gòu)簡圖如圖2所示，它是由油缸、滑臺，自凋背壓閥和聯(lián)接管路等組成。功率鍵合圖是一功效流圖，它是按著系統(tǒng)的能量傳遞方式，以實(shí)際結(jié)構(gòu)為基礎(chǔ)，用集中參數(shù)把子系統(tǒng)之間的作用關(guān)系抽象地表示為阻性元R、容性元C和感性元I的三種作用元。采用這種方法建模物理概念清晰，結(jié)合狀態(tài)空間分析法可以較準(zhǔn)確地描述和分析線

6、性系統(tǒng)，該方法在時(shí)域中研究復(fù)雜非線性系統(tǒng)動態(tài)特性的一種有效的方法。根據(jù)自調(diào)背壓調(diào)速系統(tǒng)各元件的主要特性和建模規(guī)則1，得出了圖3所示的系統(tǒng)的功率鍵合圖。圖中每根鍵上的半箭頭表示功率流向，構(gòu)成功率的兩個(gè)變量是力變量（油壓P或作用力F）和流變量（流量q或速度v）。O結(jié)點(diǎn)表示在系統(tǒng)中屬于并聯(lián)連接，各鍵上的力變量相等而流變量之和為零；1結(jié)點(diǎn)表示在系統(tǒng)中屬于串聯(lián)連接，各鍵上流變量相等而力變量之和為零。TF表示不同能量形式間的變換器，TF下標(biāo)注的字母表示力變量或流變量的轉(zhuǎn)換比值。鍵上的短橫杠表示該鍵上兩變量間的因果關(guān)系。全箭頭表示控制關(guān)系。在三種作用元中容性元和感性元的力變量與流變量之間具有積分或微分關(guān)系，

7、因此，根據(jù)圖3可推導(dǎo)出具有九個(gè)狀態(tài)變量的復(fù)雜非線性狀態(tài)方程。本文對滑臺動態(tài)特性的研究是從滑臺的前沖和運(yùn)動平穩(wěn)性兩方面入手，用四階定步長Runge-Kutta法在IBM-PC微型計(jì)算機(jī)上進(jìn)行數(shù)字仿真,仿真結(jié)果分別如圖4和圖5所示。三、滑臺前沖滑臺前沖現(xiàn)象是作用在滑臺上的負(fù)載突然消失（如鉆削工作的情況）引起的。在此過程中，滑臺的負(fù)載F、運(yùn)動速度V、油缸兩腔壓力P3和P4的變化可從圖4仿真結(jié)果看出。當(dāng)滑臺在負(fù)載的作用下勻速運(yùn)動時(shí)，油缸無桿腔油液壓力較高油液中聚集了大量的能量。當(dāng)負(fù)載突然消失時(shí)，該腔油壓隨之迅速降低，油液從高壓態(tài)轉(zhuǎn)入低壓態(tài)的過程中向系統(tǒng)釋放很多能量，致使滑臺高速向前沖擊。然而，滑臺的前

8、沖使油缸有桿腔油液受壓引起背壓升高，從而消耗掉系統(tǒng)中的一部分能量，對滑臺的前沖起到一定的抑制作用。應(yīng)當(dāng)看到，在所研究的系統(tǒng)中，自調(diào)背壓閥的入口壓力要受到油缸兩腔油壓的綜合性作用。在負(fù)載消失的瞬間，自調(diào)背壓閥的壓力將會迅速地上升，并穩(wěn)定地處在高于初始背壓的數(shù)值以上。從圖中可見，自調(diào)背壓調(diào)速系統(tǒng)在負(fù)載消失瞬間油缸背壓力升高的幅度大于傳統(tǒng)的調(diào)速系統(tǒng)，所以，其油缸有桿腔中油液吸收的能量就多；結(jié)果，滑臺的前沖量比傳統(tǒng)調(diào)速系統(tǒng)要小大約20%?？梢姴捎米哉{(diào)背莊調(diào)速系統(tǒng)作為驅(qū)動系統(tǒng)的滑臺在抑制前沖方面具有良好的特性，其中自調(diào)背壓閥起了很大作用。四、滑臺的運(yùn)動平穩(wěn)性當(dāng)作用于滑臺上的負(fù)載作周期變化時(shí)（比如說銑削加

9、工的情況），滑臺的運(yùn)動速度將要產(chǎn)生一定的波動。為于保證加工質(zhì)量的要求，必須盡可能地減小其速度波動的范圍。而從討論問題的方便性出發(fā)來說，假設(shè)負(fù)載按正弦波的規(guī)律變化，從而得到的數(shù)字仿真結(jié)果如圖5所示。由此可見這個(gè)系統(tǒng)與傳統(tǒng)的調(diào)速系統(tǒng)有著相同的變化規(guī)律以及非常接近的數(shù)值數(shù)字。其中的原因是負(fù)載的變化幅度不大，油缸兩腔的壓力也就沒有較大變化，從而最終導(dǎo)致自調(diào)背壓閥的作用不夠明顯顯示。五、改善措施通過研究的結(jié)果表明，以自調(diào)背壓調(diào)速系統(tǒng)作為驅(qū)動系統(tǒng)的滑臺，其動態(tài)特性要比傳統(tǒng)的調(diào)速系統(tǒng)好的。要減少滑臺的前沖量，就必需在負(fù)載消失的瞬間時(shí)候迅速提高油缸有桿腔的背壓力；要提高滑臺的運(yùn)動平穩(wěn)性就需增加系統(tǒng)的剛性，主要

10、措施在于減小油液的體積。從系統(tǒng)的結(jié)構(gòu)得知，油缸有桿腔與排油管之間有一很大的容積，如圖6a所示。它的存在方面延遲和衰減了自調(diào)背壓閥的作用，另一方面也降低了系統(tǒng)的剛性，它會限制了前沖特性和運(yùn)動平穩(wěn)性的進(jìn)一步改善。因此，改善滑臺動態(tài)特性可從兩個(gè)方法進(jìn)行處理：即改變油缸容積和改變自調(diào)背壓閥結(jié)構(gòu)尺寸。通過一系統(tǒng)結(jié)構(gòu)性參數(shù)的仿真計(jì)算以及結(jié)果的比較可以得出這樣的結(jié)果：當(dāng)把油缸有桿腔與排油管間容積V4同無桿腔與進(jìn)油管間容積V3之比由原來的5.5改為1時(shí),如圖6b所示，同時(shí)，把自調(diào)背壓閥閥芯底端直徑由原來的10mm增加為13mm,阻尼三角槽邊長從原來的1mm減小到0.7mm時(shí)，可使滑臺的前沖量減小30%,過渡過

11、程時(shí)間明顯縮短了，滑臺的運(yùn)動平穩(wěn)性也將會得到很大的改善。六、結(jié)論通過理論上的分析和計(jì)算機(jī)仿真研究實(shí)驗(yàn),很明顯的是自調(diào)背壓調(diào)速系統(tǒng)作為組合機(jī)床滑臺的驅(qū)動系統(tǒng)是很有推廣使用價(jià)值的。影響滑臺動態(tài)特性的主要因素是油缸內(nèi)部結(jié)構(gòu)性和自調(diào)節(jié)背壓閥的尺寸。假如能對其進(jìn)行合理設(shè)計(jì)，可使滑臺的動態(tài)特性得到顯著地改善。同時(shí)，也說明了采用有束縛力的曲線圖和狀態(tài)空間分析法研究復(fù)雜非線性液壓系統(tǒng)的動態(tài)特性是既方便又有效的方法。英文原文翻譯文獻(xiàn)：INVESTIGATIONONDYNAMICPERFORMANCEOFSLIDEUNITINMODULARMACHINETOOL（對組合機(jī)床滑臺動態(tài)性能的調(diào)查報(bào)告）文獻(xiàn)作者：Pet

12、erDransfield,出處：PeterDransfield,HydraulicControlSystem-DesignandAnalysisofTheirDynamics,Springer-Verlag,1981INVESTIGATIONONDYNAMICPERFORMANCEOFSLIDEUNITINMODULARMACHINETOOLPeterDransfieldThispaperdealswiththeinvestigationforslideunitsimpactandmotionstabilityinmodularmachinetoolfaymeansofthemethodofp

13、owerbondgraphandstatespaceanalysis.Thedynamicmathematicalmodelofself-adjustingbackpressurespeedcontrolsystemusedtodriveslideunitisestablished.Mainreasonsandaffectingfactorsforslideunitimpactandmotionunstabilityareanalysedthroughcomputerdigitalsimulation,Itisconcludedfromthosethat,ifthestructuraldime

14、nsionsofhydrauliccylinderandbackpressurevalvearedesignedrationally,theslideunitsdynamicswillmarkedlybeimproved.NOMENCLATURESfSeiRIih%flowsourceslidingfrictionforceinslideunitequivalentviscousfrictioncoe廿icientinslideunitmassofslideunitandcylindermassofSABPvalvespoolhydrauliccapacitancesofrodchambera

15、ndnon-rodchamberincylinderre-spec-tivelyC3RrR9Se2I4J5CACgspringcomplianceofSABPvalvehydraulicresistancesofdampingholeshydraulicresistanceoforificeofSABPvalvepresettingforceofspringinSABPvalveequivalentliquidinertiainpipelinesequivalenthydrauliccapacitancesinpipelinesequivalenthydraulicresistancesinp

16、ipelinesV-jVAoil-containingvolumesinnon-rodchamberandrodchamberrespectivelyR,P-ioilpressuresinnon-rodchamberandrodchamberrespectivelyFloadactedonslideunitVslideunitvelocity*DepartmentofMechanicalEngineering,DalianUr.iversityofTechnology,Dalian.China.INTRODUCTIONDuringoperationofmodularmachinetool,th

17、echangesofslidunitsspeedandloadactedonitinbothmagnitudeanddirectionwillaffectworkingperformar.eetoadifferentextentParticularlytheimpactcausedbysuddenvanishingofloadandthemotionunstabilityduetoperiodicalchangeofloadinoperationwillaffectthesurfacequalityoftheworkpiecemachined,andthetoolwouldbebrokenof

18、funderseriousconditions,Byusingthemethodofpowerbondgraphandstatespaceanalysis,thedynamicmathematicalmodelofthesystemusedtodriveslideunitisestablished,thatiscalledasself-adjustingbackpressurespeedcontrolsystemandabbreviatedtoSABPsystem.Inordertoimproveslideunitsdynamics,itisnecessarytofindoutthemainr

19、easonsandaffectingfactors,thatmustbebasedoncomputerdigitalsimulationandstudyontheresults.DYNAMICMATHEMATICALMODELTheschematicdiagramofSABPsystemisshowninFig.l,thesystemisusedtoperformthecycleoffeeding,stoppingandreturning.Fourwaycontrolvalveworksintherightpositionduringslideunitsfeeding.Thesupplypre

20、ssureofthepumpisapproximatelyconstantundertheactionofpressurereliefvalve,theoilthroughthecontrolvalveandpressurecompensatedflowcontrolvalveentersthenon-rodchambertoputslideunitforward.Atthesametime,theoilfromtherodchamberisdischargedthroughSABPvalveanddirectionalcontrolvalvetotank.Inthisprocess,thes

21、tateoftwocheckvalvesandpressurereliefvalveisnotchanged,Toestablishthemathematicalmodelasreasonablyandsimplyaspossible,considerationmustbefocusedonmainaffectingfactorsforacomplexnon-linearsystemsuchastheSABPsystem.Itisillustratedbytheoreticalanalysisandtestresult,thatthetransienttimeofthesystemismuch

22、longerthanthatoftheflowcontrolvalve,andtheflowrateovershootofthevalveintransientsaffectsverysmalltoslideunitspeedbecauseofthe;largeeffectivesectionalareaofnon-rodchamberincylinder.Forinvestigatingthesystemsdynamicswidelyanddeeply,theinitialmod-eltnisfurthersimplifiedinthispaper,andsothestudycanbeeff

23、icientlymadewithmicrocomputer.Itisassumedthattheflowratethroughtheflowcontrolvalveis141constantinthewholetransientprocess,andisdenotedtoaflowsource.Fig.2showsthestructurediagramofthedynamicmodelofthesystem,itiscomposedofcylinder,slideunit,SABPvalveandpipeline;etc.Byusingthemethodofpowerbondgraphands

24、tatespaceanalysisinthispaper,thedynamicmathematicalmodelofthesystemistobeestablished-Thepowerbondgraphisapowerflowdiagram,whichexpressesabstractlytheactionsamongsub-systemsasthreeeffects,i.e.resistanceeffect,capacitiveeffectandinertiaeffect,accordingtothewayofenergytransform,onthebasisofpracticalstr

25、uctureandbymeansofmethodoflumpedparameters.Themodelischaracterizedbyaclearconceptioninphysics,andnon-linearsystemcanbeaccuratelyanalysedincombinationwithmethodofstatespaceanalysis,thusitisaeffectivemethodusedinthedynamicinvestigationofcomplexnon-linearsysteminthetimedomain.Frommainperformancesofcomp

26、onentsinSAEPsystem,thepowerbondgraphofthesystemhasbeenformedbymeansoftheruleofmodelestablishingandisshowninFig.3.HalfarrowineachbondindicatesadirectionofpowerHow,twovariahlesofpowerareeffortvariableandflowvariable.O-junctionillustratesalgebraicsummationofflowvariablesatcommoneffort,i.e.parallelconne

27、ction,1-junctiondoesalgebraicsummationofeffortvariablesatcommonflow,i.e.seriesconnection.ThesymbolTFrepresentspowertransformerbetweentwotypesofenergy,andtransformingmodulusbetweeneffortsorflowsisnotedbelowthesymbolTF.Shorttransversebaracrossoneendofeachbondshowscausalitybetweentwovariables.Afullarro

28、wexpressesacontrolaction.Amongthreeactions,thereisanintegrationordifferentialformincapacitiveeffectandinertiaeffectbetweentwovariables.SostateequationmaybederivedfromFig.3,thereareninestatevariablesinthiscomplexnonlinearequation.Studyingontheslideunitsdynamicsisstartedwithimpactandmotionstability.Th

29、eequationissimulatedbyusingthemethodof4thorderRunge-KuttaintegrationprocedureonIBM-PCcomputer.Fig.4andFig.5illustratetheresultsrespectively.SLIDEUNITIMPACTSlideunitsimpactphenominonresultsfromloadsvanishinginthetransients,forexample,thesituationofdrillingthroughworkpiece,Fig.4expoundsthevariationsof

30、theloadandspeedofslideunit,thepressuresofchambersincylinder.Whenslideunitmotionsevenlyundertheactionofload,theoilpressureinnon-rodchamberisveryhigh,andthereisalotofhydraulicenergyaccumulatedinside.Thepressuredecreasesatoncewithloadsdischargingrapidly.Duringtheprocessofoilpressureconvertingfromhighto

31、low,thesystemabsorbssomeoftheenergy,soslideunitimpactsforwardwithhighspeed.Andthentheoilinrodchamberiscompressedtoincreasebackpressure,someoftheenergyisconsumed,whichplaysapartofrestrainingtheimpactoftheslideunit.ItmustbenotedthatinletpressureofSABPvalvetelysontheinteractionofpressuresoftwochambers,

32、andincreasesrapidlyattheinstantofloadsvanishing,andthenstabilizesatsomevaluegreaterthaninitialone.Thispressureisalsogreaterthanoneoftraditionalspeedcontrolsystem,thereforetheenergycanbeabsorbedmuchmoreintherodchamber.Inresult,theimpactofslideunitinSABPsystemis20%lawerthanintraditionals.Itisthusclear

33、thatslideunitwithSABPsystemfordrivinghasagoodperformanceinrestrainingtheimpactandSABPvalveplaysanimportantpartinthat,MOTIONSTABILITYWhenloadactingonslideunitvariesperiodically,suchasthesituationofmilling,slideunitsspeedwillbringaboutsomepulse.Inordertomeettherequirementsofmanufacturingquality,themag

34、nitudeofthespeedpulsemustbereducedassmallaspossible.Thevariationoftheloadisassumedtobeofsinewave,inordertosimplifydiscussionoftheproblem,TheresultofdigitalsimulationisshowninFig.5Itcanbeseenthat,theresponseofthesystemisthesameastraditionlsandthedifferencesbetweenthemareverysmall.Thereasonforthisisth

35、atthevariationoftheloadisnottarge,therethepressuresinchambersvaryverylittlethatis,theeffectoftheSABPvalveisnotobvious.IMPROVEMENTItisshownbystudying,thatdynamicsofslideunitwhichusedSABPspeedcontrolsystemasdrivingsystemisbetterthanthatoftraditionalsystem.Toreducetheslideunitsimpact,thebackpressureofr

36、odchamberhastobeincreasedrapidlyinthetransientsofloadsvanishing;ontheotherhand,toenhancetheslideunitsmotionstability,itisnecessarytoraisethesystemrigidity.However,mainrecommendationliesindecreasingthevolumeofoil.Itisknownfromsystemstructurethat,thereisalotofoil-containingvolumebetweentherodchamberan

37、ddrainpipeasshowninFig.6a.Becausethevolumeexists,notonlytheeffectofSABPvalveisdelayedandreduced,hutalsotherigidityofthesystemisdecreased.Therefore,itishinderedtofurtherimprovetheimpactandmotionstability.Tomaketheslideunitdynamicsbetter,thestructuraldimensionsofcylinderschamberandtheSABPvalvemustbedesignedsuitably.Basedonsimulationsunderthevariousstructuraldimensionsandcomparisonamongtheresul