机械外文文献.pdf

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1、AnElectric-power-savingHydraulicFatigue-testingMachineMechanicalhydraulic-pulsatormachinewiththreecontrolloopshasbeenconstructed.Stabilityofcontrolis0.5percentoftherange.Consumptionofelectricpowerisaboutonethirdofelectro-hydraulicmachinebyA.OhtaandE.SasakiABSTRACTAnhydrauli

2、cfatigue-testingmachinecombin-constructionandinoperation.Incasealaboratoryingamechanicalhydraulicpulsatorandaclosed-loopcontroldoesnothaveasufficientlylargeelectricsupplysys-systemhasbeenconstructedasatrial.Thedynamiccapaci-tem,thiskindofmachinecannotbeequipped.Onthetiesfor

3、loadandstrokerangesare1MNsuperposedbyaotherhand,themechanicalhydraulicpulsatorma-meanloadrangingfrom0to1MNand5ram,respectively,chine3needslesselectricpowerandlesswaterforoverafrequencyrangefrom3.3to10Hz.Theconsumptioncoolingthantheservo-controlledelectro-hydraulicofelectric

4、powerandtootingwaterforthismachineisaboutmachinedoes.However,thismachinehasanopen-onethirdoftheservo-controlledelectro-hydraulicmachine.Thestabilityofthiscontrolsystemis0.5percentoftheloopcontrolsystem.Thatis,oncetheamplituderange.Someexperimentalresultsarepresentedtodemon-

5、valueofloadhasbeensetatthebeginningofthestratetheexcellentstabilityofloadduringfatiguetesting.test,thisvalueisnotcontrolledautomatically.More-over,themeanvalueofloadiskeptonlywithin5Introductionpercentofloadrangebyanactionoftwooil-pressureswitcheswhichareconnectedthroughthe

6、mechani-Hydraulicandresonant-typefatigue-testingmachinescal-pulsatorunitbymeansofarotaryvalvecon-areusedforhigh-loadfatiguetests.l,2Theresonant-nectedtotheworkingcylinders.Thison-offcontroltypemachinecanberunwithasmallamountofsystemcannotmaintainthesetvalueatthebeginningele

7、ctricpower;howeveritcannotberuninahigh-ofthetestbecauseofthechangeinthecomplianceofdampingconditionofspecimens,orlongstrokeandthespecimenandthechangeinthetemperatureofhigh-loadfatiguetest.Thehydraulic-typemachinestheoil.canberunintheseconditions.Thus,thehydraulicTherefore,a

8、noperatorhastocorrectmanuallythefatigue-testingmachinesareusedforhigh-loadandloadt