Improving the energy efficiency of vertical injection molding machine
Currentlyvertical injection moldingmachine is mainlydivided into fourcategories:machinehingevertical injection molding machine, hydraulic type verticalinjection molding machine,fully electricandhybrid-type vertical injection molding machinevertical injection molding machine. Machinehingevertical injection molding machineusingfive-linkmechanism hasenergizingandself-lockingfeatureto promotetemplatemoldandclampingsystembyproportional valveformulti-stagepressureand speedcontrol; fully hydraulicvertical injection molding machineisdirecthydraulicclampingpressure clampingmechanism, so that force uniformtemplate, the template will notoccurdue touneven forcedeformation, stresspointsensureconsistentmold, can produce uniformand stable products; fully electricvertical injectionmachineto save energy, precision and other advantages bywidespread concernin the industry, althoughfast,precise controlandpower,but the highprice, somany customersprohibitive; hydraulic-electrichybridall-electricinjection molding machinehas the advantage ofbothinjection molding machine, retaining thehydro-mechanicalproperties ofthe injection molding machine. Thefully hydraulicvertical injection molding machinedue to thehigh costandhigh controlprecision,will become thedominantdomesticvertical injection molding machinemarket.
Fully hydraulicvertical injection molding machineenergy consumptionwas largelyfollowing sections:pumpenergy consumption; pressure lossalong the wayandlocal pressure lossconsumed; heaterpower consumptionandcirculatingcooling water pumppower consumption, whichpumpmotorelectricityaccounts for the entirevertical injection molding machinewith acapacityofmore than80 percent, followed by the loss ofhydraulicpressurecomponentsalong the way, so how toeffectively reduce theenergyconsumption ofvertical injection molding machineis veryimportant.
There isthe inevitablepressure lossalong the waywhen1.1andlocal pressure lossconsumeall types ofhydraulic valveshydraulic oilflows through thepressure lossand flowlosses, the loss ofthis part ofthe energyaccount for a largeproportion of thetotal energylosses. Therefore, a reasonablechoice of hydrauliccomponents, the pressureadjustmentvalveis also animportant aspect ofreducing thepower loss.
Flow valveflowadjustment rangebyselectingthe systemand to ensurea stableflowto meetthe minimumrequirements,the pressurevalvein the case ofhydraulic equipmentto meet thenormal work, try to takea lower pressure. Inlength, velocity, tube through thesame situation, save16%smoothmetalpipepressure lossalong the waythan therubberhose, between thesametwosmoothmetaltubeis relativelyshorter than therubberhosesection, so the totalpressure lossalong the waycan save about25%.
Secondly, whenthe rationalchoice of hydraulicoil, hydraulic oilflowin the pipeline, the viscositywill appear, and when theviscosityis too high,willhave a greaterinternal friction, resulting in heating oil, while increasingoil flowresistance.When theviscosityis too low,could easily lead toleaks,will reducethe volumetric efficiency ofthe system, therefore, generallyselectthe appropriateviscosityandgoodviscosity-temperaturecharacteristics ofthe oil. Further, when theoil flowin the pipewhenthere isapressure lossalong the way, and local pressure loss, and thereforethe design ofthe pipelineas short as possible, while reducing thebending.
1.2Otherenergylossenergyconsumptionof the heaterpower consumptionisa relatively largecomponent, however,does not representa large powerconsumption oflargeenergy consumption, butrepresentativesreach theirsetpointtemperaturetuberequired. Therefore, energy conservation is to protectthe mainheaterinsulationcover, protective coverbottomtemperature, convection andradiationheat lossratewillreduceheat lossalsoreduced,but alsoreduce the risk ofinjuryShuo. In addition, toavoid thefanblowingtubescope toreduce forcedconvectiveheat loss.Circulatingcooling water pumppower consumption(in the injection molding workshop,usuallymore than onevertical injection moldingmachines to sharea singlecooling water pump), this part of theenergy consumptionis relativelysmall.
2full hydraulicvertical injection moldingmachine hydraulic systemto improvepower lossmethod
Hydraulic transmission: It is based onthe hydraulic oilas the working medium, through the powercomponents(oil pump) the originalmotivationof mechanical energyintohydraulic oil pressurecan, and thenthrough the controlcomponents, and thenby means ofthe implementation ofthe components(hydraulic cylinder or hydraulic motor) hydraulic energyis converted tomechanical energyto drive the loadto achievethe linearor rotarymotion, andbymanipulation ofthe remotecontrol unitfor flow regulation, and adjustthe forceand speed ofexecutioncomponents.
Energy2.1conventional hydraulic-driven consumption ofvertical injection molding machine
Verticalinjection molding machinehydraulic driverequiredat all stages ofthe injection moldingpressure and flowarechanging, when the oilneedschangingvertical injection moldingmachine, located in thepumpoutletbyproportional flowvalvesand proportionalpressure reliefvalveto adjust theload pressureand flow, providingallcylinders andhydraulicmotorsrequiredthrust, pressure, direction and speed. The outputpower is equal tothe pumpmotor outputtorque andmotor speedof the product,when the systemrequires lowflow, thepump motoroutputpower constant, excesshydraulic oilback into the tankthrough aproportional valveandpressurerelief valve,even ifemptyload (cooling), too, so that the throttlingloss of poweris very large, inefficient,generally only60% to70%, resulting in a waste of energy, and because of the long-termfullof hydraulic oilcirculating throughthe hydraulicparts,mechanical partsintensefriction, resulting in high oil temperature, excessive noiseand otherproblems, machine lifeis alsoshortened.
2.2Useof energy-savinginverter controlpump-motor
Inverter controlpump-motorovercomea fundamentaltraditionalvertical injection molding machineenergy wasteills, when the flow system needs tochange,the motor speedalso followedchanges, so that the quantitative pumpdischargeflow ratechanges,that is, "how much neededsupply", thus saving a lot ofenergy.Depending on theinjection molding products, energy-saving rateof 20% to70%and nowthe structureand working principlebrief analysis ofvariable displacement pumpvariablepumppressureclosed-loop controland the swash plateangleiselectrically controlledbyaproportional valve2implementation,theproportional valveby controllingthe position ofthe piston4is proportional todeterminethe position ofthe swash plate1, the pump displacementswash plate, the control slide valve3pre-pressed by the spring5, and alwaysby thepumppressure.
When the pump isnot working, and thepressurecontrol systemis zero, due to the actionof the spring 5, the swash plateis maintained at+ 100% position, when the pump is startedasthe proportional solenoidvalve 8 isenergized, the system is switchedto zerostroke pressurein this casethe slidevalve 9 ispushedby the spring10to the initial position, when the pump pressurepis applied to thethroughportaon thecontrol piston4.
Forcepump pressureregulatingslide valvespring5 onequilibrium, the pumppressurebetween0.8 ~ 1.2MpA.Thebasic settingisinclosed-loop controlcircuit does not workwhenimplemented, controlof theproportional valveshall be borne bythe systemfromthe control panel, allthe variablesused to controlsignals requiredbythepumpcontrol panelto deal with,respectively,thecontrol boardthe actual valueof thepressure and theinclination ofthe swash platecommand valuesforthe inputpressure ofthe samplethrough apressure sensormounted onthe pumpdisplacementsensor providesapump swashplate angleactual value, the actual valueobtainedby theprocessingandthe instruction valueamplifiercomparing theminimum signalgenerator will automaticallyensure thatonlythe selectedcontrolfunctionat the desiredoperating point.
Therefore,system parameters(pressure, inclination or power) can be accuratelycontrolled, andthe other two parametersbelow a givencommand value. The minimumoutput signalas a commandsignal generatorcircuit,a valvecontrolloopvalues.The actualposition ofthe spool valve bodyis provided byan inductivesensor 6. Outputvaluevalveposition controlleroutputvia the outputof the amplifier, the decisionproportional solenoidcurrent8. Upon reachingthe operating point, the ratio of thevalve body9is held in theintermediate position.If thehigher-levelcontroller isnecessary to increase theinclination(increased traffic), the spool 9need todeviate from themiddle position(the control piston4through thevalve portA → T),until theangle reachesthe desired value. By increasing theproportional solenoidcurrenteightto overcomethe forceof the spring10so thatthe spoolmoves. When theneed to reduce theinclination angle, the control channelof the piston 4isp → A.
Application2.3proportional variablepump systemso that the entirehydraulicvertical injection moldingmachine hydraulic systemto reducefever, extend the life ofhydraulic components; reduceenergy consumption, improvesystem efficiency; and to achievenumericalproportion ofbackpressurecontrol, improvedplasticizingeffect;reducethe level ofpollutionof hydraulicsystems, system failures significantly reduced.
Inan increasinglyseriousenergysupplynow, energy is undoubtedlyoneof the more importanttopics,vertical injection molding machineenergy consumptionis relatively large,itis imperative tosaving, the paper mainlyvertical injection molding machinecan befromseveral majorenergycomponentsconsumption, and to investigate the relevantenergy-saving measures, andto share whattrendsvertical injection molding machinetoget betterto improveenergy efficiency.