《數(shù)控應(yīng)用專業(yè)英語》課件第9章

9SPINDLESPEEDFUNCTION(SFUNCTION)9.1SPECIFYINGTHESPINDLESPEEDWITHACODE9.2SPECIFYINGTHESPINDLESPEEDVALUE

DIRECTLY(S5-DIGITCOMMAND)9.3CONSTANTSURFACESPEEDCONTROL(G96,G97)9.4SPINDLESPEEDFLUCTUATIONDETECTION

FUNCTION(G25,G26)9.1SPECIFYINGTHESPINDLESPEEDWITHACODE

WhenavalueisspecifiedafteraddressS,thecodesignalandstrobesignalaresenttothemachinetocontrolthespindlerotationspeed.

AblockcancontainonlyoneScode.RefertotheappropriatemanualprovidedbythemachinetoolbuilderfordetailssuchasthenumberofdigitsinanScodeortheexecutionorderwhenamovecommandandanScodecommandareinthesameblock.9.2SPECIFYINGTHESPINDLESPEEDVALUEDIRECTLY(S5-DIGITCOMMAND)

ThespindlespeedcanbespecifieddirectlybyaddressSfollowedbyamax.fivedigitvalue(rpm).Theunitforspecifyingthespindlespeedmayvarydependingonthemachinetoolbuilder.Refertotheappropriatemanualprovidedbythemachinetoolbuilderfordetails.9.3CONSTANTSURFACESPEEDCONTROL(G96,G97)·Constantsurfacespeedcontrolcommand

G96S□□□□□;↓

Surfacespeed(m/minorfeet/min)

Note

Thissurfacespeedunitmaychangeaccordingtomachinetoolbuilder’sspecification.·Constantsurfacespeedcontrolcancelcommand

G97S□□□□□;↓

Spindlespeed(rpm)

Note

Thissurfacespeedunitmaychangeaccordingtomachinetoolbuilder’sspecification.·Constantsurfacespeedcontrolledaxiscommand

G96Pα;

P0:axissetintheparameter.

P1:Xaxis；P2:Yaxis；P3:Zaxis；P4:4thaxis;

P5:5thaxis；P6:6thaxis；P7:7thaxis；P8:8thaxis.·ClampofmaximumspindlespeedG92S-;

Themaximumspindlespeed(rpm)followsS.Explanations·Constantsurfacespeedcontrolcommand(G96)

G96(constantsurfacespeedcontrolcommand)isamodalGcode.AfteraG96commandisspecified,theprogramenterstheconstantsurfacespeedcontrolmode(G96mode)andspecifiedSvaluesareassumedasasurfacespeed.AG96commandmustspecifytheaxisalongwhichconstantsurfacespeedcontrolisapplied.AG97commandcancelstheG96mode.Whenconstantsurfacespeedcontrolisapplied,aspindlespeedhigherthanthevaluespecifiedinG92S-;(maximumspindlespeed)isclampedatthemaximumspindlespeed.Whenthepoweristurnedon,themaximumspindlespeedisnotyetsetFig.9.3(a)Relationbetweenworkpieceradius,spindlespeedandsurfacespeedandthespeedisnotclamped.S(surfacespeed)commandsintheG96modeareassumedasS=0(thesurfacespeedis0)untilM03(rotatingthespindleinthepositivedirection)orM04(rotatingthespindleinthenegativedirection)appearsintheprogram.·Settingtheworkpiececoordinatesystemforconstantsurfacespeedcontrol

Toexecutetheconstantsurfacespeedcontrol,itisnecessarytosettheworkcoordinatesystem,andsothecoordinatevalueatthecenteroftherotaryaxis,forexample,Zaxis,(axistowhichtheconstantsurfacespeedcontrolapplies)becomeszero.Fig.9.3(b)Exampleoftheworkpiececoordinatesystemforconstantsurfacespeedcontrol·SurfacespeedspecifiedintheG96modeFig.9.3(c)SurfacespeedspecifiedintheG96modeRestrictions·Constantsurfacespeedcontrolforthreading

Theconstantsurfacespeedcontrolisalsoeffectiveduringthreading.

Accordingly,itisrecommendedthattheconstantsurfacespeedcontrolbeinvalidatedwithG97commandbeforestartingthescrollthreadingandtaperthreading,becausetheresponseproblemintheservosystemmaynotbeconsideredwhenthespindlespeedchanges.

·Constantsurfacespeedcontrolforrapidtraverse(G00)

InarapidtraverseblockspecifiedbyG00,theconstantsurfacespeedcontrolisnotmadebycalculatingthesurfacespeedtoatransientchangeofthetoolposition,butismadebycalculatingthesurfacespeedbasedonthepositionattheendpointoftherapidtraverseblock,ontheconditionthatcuttingisnotexecutedatrapidtraverse.9.4SPINDLESPEEDFLUCTUATIONDETECTIONFUNCTION(G25,G26)

Withthisfunction,anoverheatalarm(No.704)israisedwhenthespindlespeeddeviatesfromthespecifiedspeedduetomachineconditions.

Thisfunctionisuseful,forexample,forpreventingtheseizureoftheguidebushing.

Format

G26:enablesspindlespeedfluctuationdetection.

G25:disablesspindlespeedfluctuationdetection.

G26PpQqRr;Spindlefluctuationdetectionon

G25;

Spindlefluctuationdetectionoff

p:time(inms)fromtheissueofanewspindlerotationcommand(Scommand)tothestartofcheckingwhethertheactualspindlespeedissofastthatanoverheatcanoccur.

WhenaspecifiedspeedisreachedwithinthetimeperiodofP,acheckisstartedatthattime.

q:tolerance(%)ofaspecifiedspindlespeed.

Ifaspecifiedspindlespeedlieswithinthisrange,itisregardedashavingreachedthespecifiedvalue.Then,thecheckingofanactualspindlespeedisstarted.

r:spindlespeedfluctuation(%)atwhichtheactualspindlespeedissofastthatanoverheatcanoccur.

G26enablesthespindlespeedfluctuationdetectionfunction,andG25disablesthespindlespeedfluctuationdetection.

EvenifG25isspecified,p,q,andrarenotcleared.Explanations

Thefluctuationofthespindlespeedisdetectedasfollows.·WhenanalarmisissuedafteraspecifiedspindlespeedisreachedFig.9.4(a)Analarmisissuedafteraspecifiedspindlespeedisreached·WhenanalarmisissuedbeforeaspecifiedspindlespeedisreachedFig.9.4(b)Analarmisissuedbeforeaspecifiedspindlespeedisreached

(ⅰ)Specifiedspeed:

(speedspecifiedbyaddressSandfivedigitvalue)·(spindleoverride)

(ⅱ)Actualspeed:speeddetectedwithapositioncoder.

p:timeelapsessincethespecifiedspeedchangesuntilacheckstarts.

q:(percentagetoleranceforachecktostart)·(specifiedspeed).

r:(percentagefluctuationdetectedasanalarmcondition)·(specifiedspeed).

d:fluctuationdetectedasanalarm(specifiedinparameter).

Analarmisissuedwhenthedifferencebetweenthespecifiedspeedandtheactualspeedexceedsbothrandd.NOTE

(ⅰ)Whenanalarm