工程基础注塑机

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1、工程基础注塑机ENGINEERINGBASICSforINJECTIONMOULDINGMACHINE.工程基础注塑机。ENERGYEnergyiscapacitytodowork.Workisdonewhenaforcemovesitspointofapplicationinthedirectionofforce.=forcexdistancemoved.Powerisrateofdoingwork.Power=forcex(distance/time).Thisalsocalledenergy.Energycanneitherbecreatednord

2、estroyedbutonlytransformedfromoneformtoothers.MACHINEAmachineisadevicethatmakestheworkeasier.·Thiscanhappenbyapplicationsmallerforce(leverprinciple)togetbiggerforcetodotheworkor·Changinglineofactionofforce.Machinecannotcreateenergybyitself.Therefore,machinerequiresaprimemover.Inmo

3、stofthemachinesprimemoverisanElectricalmotor-3phasesquirrelcageInductionmotorincaseofInjectionMouldingMachine.Inthismachineelectricalenergyisconvertedtomechanicalenergythroughhydraulics.PRIM-MOVERElectricmotoriscoupledtohydraulicpump.Pumphasflowrating-say100literspermin.or25gpm.Pu

4、mpdeliversoilflowinthesystem.Oilflowmeetsresistancecausingresultantpressureinthesystem.ThehydraulicsystemincludesReliefValvesforpressurelimit,FlowcontrolValvesforspeedandDirectionalvalvesfordirectingoiltoActuators-CylinderforlinearmovementandHydromotorforrotarymovement.Foreachtoan

5、dfromovementtheremustbeonecylinderasactuator.Thereforetherearecylindersformouldopen/close,injectionunitforward/retract,Injection/retract.AndHydro-motorforscrewrotation,PUMPPumpdeliversoilflowinthesystematratedflowratetilltheresistancereachessay150bar.Thereafterfurtherincreaseinloa

6、dpressuredecreasestheflowrate.Manyinthemouldingshopfloorwronglybelievethatpumpcreatespressure.Pumpcreatesflowratenotpressure.Therefore,hydraulicsystempressureisnotallowedtogobeyond150barbyMainReliefValveinthesystem.  PRESSUREThemeltispushedbythescrewtipthroughnozzleintothemould.As

7、themeltmovesinsidethemould,resistancetoflowbuildsupandhencemeltpressureatscrewtipincreases.Thisisreflectedatthehydraulicpressuregaugeatinjectionhydrauliccylinder.Here,PsAs=PhAhPsispressureatscrewtipinbarrelandPhishydraulicpressureatinjectionhydrauliccylinder.Asiscrosssectionareaof

8、screwandAhiscrosssectionareaofpis