外文翻译中英文-环间距对悬臂型掘进机截割头性能的影响

第1页翻译部分英文原文EffectsofcircumferentialpickspacingonboomtyperoadheadercuttingheadperformanceE.MustafaEyyuboglua,*,NaciBolukbasibAbstract：Effectsofequalandunequalcircumferentialpickspacingontheperformanceofboomtyperoadheadershavingcylindricalcuttingheadsareinvestigated.Forthispurpose,twoexperimentalcuttingheadswithequalandunequalcircumferentialspacingaredesignedandmanufactured.Thecuttingheadwithunequalcircumferentialspacingisspecificallydesignedtopreventtool-holderoverlapatthenosesection.Manufacturingdifficultiesassociatedwithequalcircumferentialpickspacingduetotool-holderoverlaparediscussedwithsolidmodelingandpracticalapplications.TheheadsaretestedatParkCayirhanCoalMineinTurkeyandtheircuttingperformancesareanalysed.Althoughbettercuttingperformanceforequalcircumferentialspacingarepredictedbyforcebalanceanalysis,insitumeasurementsofinstantaneous(net)traversingspeedandcuttingrate,pickconsumptionrateandmachinevibrationshowthatnosignificantdifferenceexistsbetweentheperformancesofthetwocuttingheads.Keywords:Roadheaders;Cuttingheaddesign;Circumferentialpickspacing;Performanceprediction1.IntroductionOneofthemostimportantconsiderationincuttingheaddesignistheminimisationofforcevariationimposedoncuttingpicks,whichalsominimizesvibrationoncuttingheadandincreasescuttingefficiency.Forcevariationsoncuttingheadsaremaintainedatminimumlevelbyprovidingequalpickspacingaroundtheentirecuttingheadperiphery(HurtandMacAndrew,1981;Hurtetal.,1982;HurtandMacAndrew,1985).However,thelimitedavailablespacefortool-holdersatthenosesectionofcuttingheadshindersthedistributionofpicksatequalperipheralspacing.Ontheotherhand,thecuttingconditionsofpickscreatedisproportionalpickforcedistributionaroundthecuttingheadsuchasthecornercuttingpicks,whichfacehigherforcesthanthetraversingpicksduetodifficultcornercuttingconditions.HurtandMacAndrew(1985)proposedtheapplicationofgradedlacingatthecornercuttingregioninordertobalancethepickforces.However,anyachievementforequalizationofpickforcesaroundthecuttingheadhasnotbeencitedyet.Pickspacingsaroundthecuttingheadaredefinedaslinespacing(SL)andcircumferentialspacing(Cs)asshowninFig.1.Linespacingisthedistancebetweenthecuttinglinesalongthelengthofthecuttingheadanddependsmainlyonthedepthofcutandcuttabilityofmaterialbeingcut.Circumferentialpickspacingistheangulardistancebetweenthepicksmeasuredperpendiculartotheaxisofrotation,whichismainly第2页relatedtotheangleofwrap,headdiameter,linespacing,totalnumberofpicks,tool-holdersizeandadditionalspacerequiredforwatersprays.Linespacingbetweenpicksdirectlycontrolsthecross-sectionalareasweptbypicks,hence,theforcelevelimposedonpicks.Theeffectsoflinespacingonroadheadercuttingheadperformancehavebeenstudiedsystematicallyandwelldocumented(Evans,1972;Roxborough,1973;HurtandMacAndrew,1981;Hurtetal.,1982;HurtandMacAndrew,1985).Anyfailureinprovidingequallinespacingtriggersdisproportionalpickforcesandconsequentlyhighcuttingheadvibration.Therefore,toeliminateforcefluctuationsonpicks,linespacinghastobekeptapproximatelyconstantaroundthecuttingheadperiphery.Circumferentialspacing,ontheotherhand,controlsthesequenceofpicksduringcutting.Although,Hurtetal.(1982)andHekimogluandFowell(1991)suggestedtokeepcircumferentialpickspacingequal第3页aroundthecuttingheadperiphery,consideringforcebalanceanalyses,theeffectsofequalcircumferentialspacingoncuttingheadperformancehasnot,sofar,beeninvestigatedcomprehensively,particularlyunderpracticalconditions.TheclassificationsoflacingpatternsatdifferentanglesofwrapwerestudiedbyHekimogluandFowell(1991)concludingthat360andovercouldbeemployedwithslighttrimmingofthetool-holderstoobtainequalcircumferentialpickspacing.Eyyuboglu(2000)carriedoutinsituteststocomparelacingpatternswithequalcircumferentialspacingatdifferentanglesofwrapbyusingcuttingheadsfittedwithlight-dutypicks.ItwasdeterminedbyEyyuboglu(2000)thatthemostsuitableanglesofwrapwere360and776withoutsignificantdifferencebetweenthem.第4页However,previousinvestigationshavenotproventhatequalcircumferentialspacingcouldyieldbetterresultsthanunequalspacinginpractice.Applicationofequalcircumferentialspacingoncylindricalcuttingheadscausestool-holderoverlapatthenosesectionduetoinsufficientspaceavailable,whichcreatesmanufacturingdifficultiesasmentionedbyHekimogluandFowell(1991).Thedegreeofoverlapisinfluencedbythecircumferentialandlinespacings,totalnumberofpicks,headdiameter,tool-holdersizeandadditionalspacerequiredforwatersprays.Severetool-holderoverlapatthenosesectionunderadverseconditionsmakesimpossibletoapplyequalcircumferentialspacing.Themostoftheroadheadercuttingheadsinpracticearemanufacturedwithunequalcircumferentialspacingduetotool-holderoverlap.Inthispaper,theeffectsofbothequalandunequalcircumferentialpickspacingontheperformanceofcylindricaltyperoadheadercuttingheadswithhemisphericalnoseareinvestigatedonthebasisofthepredictedandinsitumeasurements.Manufacturingdifficultiesduetotoolholderoverlapproblemarealsostudiedbysolidmodelingandpracticalapplications.2.DesignandmanufactureofexperimentalcuttingheadsInordertocomparetheeffectsofequalandunequalcircumferentialpickspacingoncuttingheadperformance,thecuttingheadswithequalandunequalcircumferentialspacingusinglightandheavy-dutycuttingpicksaredesignedandmanufactured.Thefirstandthesecondcuttingheadsaremanufacturedwithunequalandequalcircumferentialspacing,keepingtheothervariablesconstant.Theseheadsarefittedwith27lightdutypicksat360_angleofwrap.Itisattemptedtomanufacturethethirdcuttingheadwithheavy-dutypicksatequalcircumferentialspacing.Althoughthetotalnumberofpicksarereducedto24andheavytool-holdertrimmingisapplied,itwasnotpossibletomanufacturethisheadduetoseveretool-holderoverlap.Since第5页equalspacingcannotbeachievedwithheavy-dutypicks,thecomparisonofthecuttingheadsisonlyperformedbetweenthefirstandthesecondcuttingheadsfittedwithlight-dutypicks.However,thethirdcuttingheadisalsodiscussedtoemphasistheimpossibilityofmanufacturingtheheadwithequalcircumferentialspacingusingheavy-dutypicks.DesigndetailsofthecuttingheadsareshowninTable1andFig.2.Tool-holderoverlapexistsatthenosesectionofthecuttingheadsmainlybetweenthefirst(leading)andsecondpicksofeachspiral.Sincethemostsevereoverlapoccursbetweenthepicknumbers1and4ofthefirstspiral(seeFig.2),thepositionsofonlythesepicksareconsideredindiscussion.Thefirstcuttingheadisdesignedwithunequalcircumferentialspacingtoavoidtool-holderoverlap.Severalsolidmodelsaredrawntodeterminetheminimumcircumferentialspacing(angle)betweenthefirstandfourthpicksoverwhichtool-holderoverlapdoesnotoccur.Theappropriatespacingisdeterminedtobe57betweenthepicksunderconsideration.Then,thecircumferentialspacingisgraduallyreducedtowardstherearoftheheadduetolargerspaceavailableandkeptconstantat29fortheremainingcylindricalpartofthecuttinghead(seeFig.2).Thepositionsoffirstandfourthpicksat57_circumferentialspacingareshowninFig.3bysolidmodeling.Thesecondcuttingheadismanufacturedat40equalcircumferentialspacing.Heavytrimmingofthefirstandfourthtool-holdersisrequiredduetopresenceofserioustool-holderoverlapshownbysolidmodelinginFig.4.Thepositionsofthesetool-holdersafterbeingtrimmedandweldedonthesecondheadareshowninFig.5.Theattempttomanufacturethethirdheadwithheavy-dutypicksatequalcircumferentialspacingwasunsuccessfulevenwhenthetotalnumberofpickswasreducedfrom第6页27to24.Theresultingequalspacingat45cannotbeachievedwithKennametalU47picksduetoseriousoverlappingbetweentool-holders1and4showninFig.6bysolidmodeling.Tool-holders1and4canonlybelocatedontheheadbyincreasingthecircumferentialspacingfrom45_to55_.However,thisresultsinaheadwithunequalcircumferentialspacingstillrequiringheavytrimming(Fig.7).3.PerformancecomparisonofthecuttingheadswithequalandunequalcircumferentialspacingTheperformancesofthecuttingheadsarepredictedbyforcebalancecalculations,andthen,determinedbyinsituundergroundtrials.第7页3.1.PerformancepredictionofthecuttingheadsBreakoutpatternsandforcebalancecalculationsareusedtopredicttheperformanceofthecuttingheads.Whilethebreakoutpatternillustratesthecuttingactionofpicks,theforcebalancecalculationsandrelateddiagramscanbeusedasanindicatorofvibrationlevelforacuttinghead.Theforcebalancecalculationtechniqueassumestheroadheadertobecuttingintraversingmodeandestimatesfluctuationintorque,traversingforce,verticalandaxialforcesasthecuttingheadrotates(Hurtetal.,1988;Rostamietal.,1994).AcomputerprogramhasbeendevelopedonthebasisofthealgorithmconceptpublishedbyHurtetal.(1988)andusedtoobtainbreakoutpatternsandforcebalancediagramsofthecuttingheads.Thecalculationsaremadeatanadvancerateof50mm/revwithfulldepthofsumpfor180_cuttingsector.Fig.8illustratesthebreakoutpatternsoftheexperimentalcuttingheadsforthreerevolutions.Sincelinespacingsareequalforbothheads,theonlydifferenceisthevariationinthecuttingsequenceofthepicks.Thiscausesamaximumchangeof5%inthecross-sectionalareasweptbythepicksinbreakoutpatterns,whichcanbeneglected.ForcebalancecalculationresultsanddiagramsaregiveninTable2andFig.9,respectively.Theresultsindicatethatalthoughthemeantorqueandforcevaluesareaboutthesame,therearesignificantincreasesinthevariancevaluesofthetorque,traversingandverticalforcesoftheheadwithunequal第8页circumferentialspacing.Onereasonfortheincreaseinthevarianceisduetothevariationinthenumberofactivepickswithinthecuttingsectorwhichvariesbetween13and14fortheequal,and11and15fortheunequalcircumferentialspacingasshowninFig.10.Thehighervariationinthenumberofactivepicksforunequalspacingcauseshighervariancevalues.Also,thenumberofactivepicksincuttingsectorvariesregularlyforequalspacing,whereasthevariationisirregularforunequalcircumferentialspacingwhichisthesecondreasonfortheincreaseinvariance.3.2.UndergroundtrialsofthecuttingheadsTheexperimentalcuttingheadsaretestedindrivingtheC0210gateroadwayatParkCayirhanCoalMineinTurkeyusingDoscoMK2Bboomtyperoadheader.Thegateroadwayisdrivenatacross-sectionof24m2incoalincludingsiltstoneintercalationwithathicknessofabout0.8m.Totallengthsof275and308maredrivenusingthecuttingheadshavingunequal第9页andequalcircumferentialspacing,respectively.Pickconsumption,instantaneoustraversingspeedandcuttingrate,vibrationandaccelerationvaluesareconsideredasthebasisofperformancecomparison.Theeffectofstratastrengthchangeonexperimentalresultsisminimisedbychangingthecuttingheadsinturnafteranadvanceofabout150malongthelengthofthegateroadway.ThepickconsumptionratesobservedduringroadwaydrivagewiththecuttingheadsarepresentedinTable3.Theresultsindicatethatthepickconsumptionsoftheheadsarenearlysameandthedifferenceisnotsignificant.Instantaneoustraversingspeed,cuttingrate,vibrationandaccelerationmeasurementsarecarriedoutbytraversingthecuttingheadat180cuttingsectorwithfulldepthofsump.Separatemeasurementsareperformedatthetopandbottomcoalandattheintercalation,sincetheyhavedifferentstrengthcharacteristics.Cuttingtrialsarerepeatedatleast10timesforeachtypeofmaterial.MeasurementresultspresentedinTable4showthatthereisnosignificantdifferenceininstantaneoustraversingspeedandcuttingratesforthetwotypesofcuttingheads.Dataloggersareinstalledontheboomoftheroadheadertomeasurethevibrationandaccelerationoftheheadduringtraversinginverticaldirection.Tinytag第10页PlusVibrationLoggerTGP0650andTinytagPlusShockLoggerTGP0610whichcanmeasureintherangeof20Hzand1kHzareusedinthefieldtrials.Hurtetal.(1988)andMinetal.(2003)consideredthisrangetobesuitabletomeasurevibrationandaccelerationatroadheaders.Dataloggersareprogrammedtotakemeasurementsatonesecondintervals.MeasurementsareoffloadedtocomputerusingGLMVersion2.3software.Thedataloggershavingpeak-holdcharacteristicmeasurethehighestvaluewithineachintervalforwhichtheyareprogrammed.Vibrationandaccelerationmeasurementresultsforthetwotypesofheadsindicatenosignificantdifferencebetweenthem.Theslightvariation,ontheotherhand,isareflectionofchangesinstrengthcharacteristicsofthematerialsandmeasurementsensitivity.4.ConclusionsThefollowingconclusionscanbedrawnfromtheresultsobtainedinthisstudy.1.Insitutrialsshowthatnosignificantdifferenceexistsbetweentheperformancesofthecuttingheadsprovidedwithequalandunequalcircumferentialspacingintermsofpickconsumption,instantaneoustraversingspeedandcuttingrate.2.Althoughhighervibrationispredictedforthecuttingheadwithunequalcircumferentialspacingduetoirregularvariationinthenumberofactivepicksincutting,vibrationandaccelerationmeasurementresultsshownosignificantdifferenceforthetwotypesofcuttingheads.Forcebalancecalculationsassumecontinuouscuttingbypicks.Inpractice,ontheotherhand,cuttingisnotcontinuousduetoformationofchipsandirregularbreakageofthematerialduringcutting.Therefore,improvementspredictedforequalcircumferentialspacingbyforcebalancecalculationscannotberealisedinpractice.3.Significantincreasesinvibrationandaccelerationexistfortheintercalation(uniaxialcompressivestrengthrc=20MPa)ascomparedtothecoal(rc=10MPa)whencuttingwithbothheads.Vibrationandacceleration,thustheforcebalancediagramsareaffectedbythechangesinthestrengthcharacteristicsofthestrataatthefaceratherthanwhetherthecircumferentialspacingisequalorunequal.4.Applicationofequalcircumferentialpickspacingresultsinmanufacturingproblemsduetotool-holderoverlapatthenosesectionofthecylindricalcuttingheadsmentionedinthisstudy.Suchpickarrangementisonlypossiblewithheavytrimmingwhenthedegreeofoverlapisnothigh.Somefactors,particularlytheuseofheavy-dutypicksand/orwaterspraysincreasethedegreeofoverlapconsiderably,makingtheapplicationofequalcircumferentialspacingimpossible.Tool-holderoverlapcanonlybepreventedbyapplyingsufficientlylargespacingatthenosesectionresultinginunequalcircumferentialpickspacing,theapplicationofwhichisunavoidableinthemostcases.Asaresultofthepracticalstudies,itisconcludedthatequalcircumferentialspacingonacuttingheaddoesnotincreasesignificantlyitscuttingperformanceascomparedtounequalcircumferentialspacing.Therefore,theapplicationofunequalcircumferentialspacingatthenosesectiontopreventtool-holderoverlapandequalspacingattherearisabetterchoiceindesigningacuttinghead.第11页中文译文环间距对悬臂型掘进机截割头性能的影响作者：E.MustafaEyyuboglua,*,NaciBolukbasib摘要：对相等和不相等的环间距上悬臂式掘进机切割头圆柱间距接性能的影响进行研究。为此，设计和制造了两个在相等和不相等的环间距切割头的情况下的实验。不等环间距的切割头是专门用来防止工具操作人员在机头部分造成重叠。环间距相等，由于论述了实体模型和实际应用中齿座与截齿的重叠，选择相关制造出现了很多困难。在Cayirhan公园煤矿矿井和在土耳其对测试头部切削性能进行了分析。虽然环间距相等圆周切割性能预测力平衡分析在瞬间（净值）移动速度和切削率原位测量更好，但消耗率和机械振动显示，存在没有明显差异的两个切割头的现象。2005年爱思唯尔有限公司保留所有权利。关键词：掘进机，截割头的设计;周回升间距;性能预测1简介切割头的设计中最重要的考虑因素之一是尽量减少切割力的变化，即在最大限度地减少切割头的震动情况下提高切削效率。通过提供相等的间距参数选择在整个切削头的边缘使切削力的变化保持在最低水平（Hurt和马坎德鲁，1981;伤害等，1982.Hurt和马坎德鲁，1985）。然而,机器设计在机头部分的分配有限的可用空间导致阻碍了分布的截割头在相同的周边间隔。另一方面，截割头所处的切割条件导致不对称的截割力，如在切割条件不良好的情况下截割头角落承受更高的压力。马坎德鲁（1985）提出了在切削区域分级，以及平衡力量的花边的应用。然而，选择切割头的任何平均压力的已有成就还没有被引用.圆切割头截线间距是指间距（SL）和环间距（Cs），如图1所示。行距之间的距离是指沿长度和切割头的切割线。这主要取决于切割的材料和被切割有效深度。环间距是实测的垂直旋转度，这主要涉及形状，头部直径，行距，总截割头数，设计人员分配的预留空间大小和需要的角度及喷水轴的角回升距离。如图一所示。图1线和切割头的环间距第12页线之间的间距为直接控制的横截面面积大小，因此，在对掘进机的截割头线间距性能的影响进行了研究后可以得出结论为功率级别决定截割头（埃文斯，1972年;罗克斯伯勒，1973;Hurt和马坎德鲁，1981;Hert等，1982.Hurt和马坎德鲁，1985）。提供相等的任何故障触发线间距不相称的力量，因此选择高切割头振动。因此，要消除截割力的波动，行间距必须保持与切割头左右间距不变。另一方面，周间距控制切割过程中的截割顺序。保持周围环接间距相等的切割头周边，在考虑到动力-平衡分析的情况下，切割头间距相等对截割头的性能没有影响。到目前为止，已进行了全面调查，特别是在现实条件下。在对铸造不同的角度和花边图案的分类情况下进行研究的基础上Hekimoglu和Fowell（1991）提出是可以使用用微型的工具修改以取得平等周回升距离。Eyyuboglu（2000年）进行了原位通过测试，以比较花边用轻型带切割头装备不同的角度间距情况下相等的圆周图案。它是由Eyyuboglu决定（2000）来表示，最合适的角度间无明显差异。然而，以往的调查还没有证明周间距相等可以产生更好的结果。在实践中的不相等间距和相等的圆周的圆柱切割头间距的应用使设计人员由于没有足够的可用空间导致工具在机头部分产生重叠。即由Hekimoglu和Fowell（1991）中提到的制造困难。重叠程度影响的圆周和行间距，总数采用头部直径，额外需要洒水的空间.恶虐工况下导致机头部分重叠，使无法适用环间距相等。在本文中，双方相等的和不相等的影响，周截割头间距对圆柱型掘进机的性能影响表现在切割头与半球顶端进行调查的基础上的预测及原位测量。由于制造困难及刀架重叠的问题也可采用实体建模和实际应用研究。2.实验设计与制造切割头为了比较的相等和不相等的圆周切割头间距性能的影响，与相等的和不相等的切割头环利用间距，重型截齿的设计和制造。第一个和第二个切割头制造成相等的和不等周间距，保持其他变量不变.这些截割采用27轻型360度轻型包角装置。这是企图制造周间距相等的第三个重型采割头.虽然截割头总数被减少到24个同时重型的工具架被应用，因严重的工具架重叠它是不可能制造出。由于间距相等不能与重型截割头同时实现，在该切割头之间进行比较，只有第一个和第二个切割头装有轻型截齿。然而，第三切割头还讨论了截割头的制造与使用同等周间距重型截齿是不可能的。切割头的设计细节都显示在表1和图2.工具架重叠在切割