試驗(yàn)指導(dǎo)書五軸數(shù)控磨刀機(jī)原理及實(shí)踐

1、實(shí)驗(yàn)指導(dǎo)書五軸數(shù)控磨刀機(jī)原理及實(shí)踐要加工出合格的工件，必須根據(jù)工件的加工工藝要求，正確地設(shè)計(jì)和使用刀具，以保證達(dá)到工件所要求地尺寸、形狀精度和表面質(zhì)量。金屬切削刀具的種類很多，對(duì)于標(biāo)準(zhǔn)刀具，需要根據(jù)刀具的工作原理和結(jié)構(gòu)特點(diǎn)正確地選擇和使用；對(duì)于非標(biāo)準(zhǔn)刀具則需要根據(jù)工件的加工要求進(jìn)行專門的設(shè)計(jì)和制造。經(jīng)過精心準(zhǔn)備，制造工程基礎(chǔ)教學(xué)組與德國(guó)saacke公司培訓(xùn)中心嘗試進(jìn)行校企合作開展學(xué)生實(shí)驗(yàn)課程的工作。本次實(shí)驗(yàn)的主要目的是結(jié)合生產(chǎn)實(shí)際，通過先進(jìn)的制造設(shè)備及手段，使學(xué)生能夠掌握刀具的設(shè)計(jì)原理，合理選擇刀具設(shè)計(jì)參數(shù)，正確設(shè)計(jì)刀具結(jié)構(gòu)，熟悉刀具從設(shè)計(jì)到制造的全過程。1 .實(shí)驗(yàn)?zāi)康? .結(jié)合生產(chǎn)實(shí)際，給學(xué)

2、生介紹先進(jìn)的生產(chǎn)理念，作為課堂內(nèi)容的拓展和補(bǔ)充，加深對(duì)所學(xué)知識(shí)的理解；2 .鍛煉實(shí)驗(yàn)設(shè)計(jì)能力和動(dòng)手能力，熟悉刀具由設(shè)計(jì)到制造的全過程；3 .掌握有關(guān)磨削加工的知識(shí)，了解刀具磨床的結(jié)構(gòu)及工作原理，；4 .掌握鉆頭設(shè)計(jì)、加工的全過程；2 .指導(dǎo)人員德國(guó)Saacke公司中國(guó)工程師、德國(guó)工程師(英語交流)、實(shí)驗(yàn)指導(dǎo)教師3 .實(shí)驗(yàn)內(nèi)容由Saacke公司的指導(dǎo)人員負(fù)責(zé)講解，并利用該公司所提供的五軸數(shù)控磨刀機(jī)及相應(yīng)的CAD/CAM軟件，參加實(shí)驗(yàn)的每組同學(xué)完成所選刀具的設(shè)計(jì)和制造。本實(shí)驗(yàn)主要包括以下內(nèi)容：(1) 講解Saacke五軸新概念刀具磨床的結(jié)構(gòu)及工作原理。(2) 講解鉆頭、銃刀等刀具設(shè)計(jì)、加工原理(3

3、) 講解有關(guān)磨削加工的知識(shí)，包括砂輪、切削液等(4) 在刀具設(shè)計(jì)加工仿真軟件上完成相應(yīng)刀具的CAM設(shè)計(jì)(5) 在Saacke五軸刀具磨床上完成所設(shè)計(jì)刀具的加工4 .實(shí)驗(yàn)設(shè)備、儀器及工具1 .機(jī)床：uwn型五軸數(shù)控磨床2 .軟件：NUMROTOplus3 .試件：45#鋼棒料（細(xì)長(zhǎng)棒料）4 .計(jì)算機(jī)5 .千分表、游標(biāo)卡尺6 .刀具角度測(cè)量?jī)x5 .準(zhǔn)備工作1 .熟悉鉆頭、銃刀的結(jié)構(gòu)特點(diǎn)、設(shè)計(jì)原理和制造方法;2 .熟悉本指導(dǎo)書附錄中關(guān)于磨削的知識(shí)；3 .牢記操作注意事項(xiàng)及操作安全。6 .UWII型五軸數(shù)控磨床簡(jiǎn)介圖1.uwn型五軸數(shù)控磨床UWH型五軸數(shù)控磨床，功率15KW,可以用于刀具的制造和修磨，

4、并可配置自動(dòng)上下料裝置，以滿足大批量生產(chǎn)的需要。機(jī)床采用Windows操作系統(tǒng)，人機(jī)對(duì)話式窗口，界面友好，旁邊有圖形支持窗口，可對(duì)加工刀具進(jìn)行三維立體顯示和加工模擬，并且留有用戶開發(fā)界面。在磨頭上裝有三維Renishaw測(cè)頭，可以對(duì)刀具的長(zhǎng)度、直徑、螺旋角等參數(shù)進(jìn)行自動(dòng)測(cè)量，并自動(dòng)輸送到計(jì)算機(jī)中，方便可靠。該機(jī)床主要技術(shù)參數(shù)如下：技術(shù)特點(diǎn)：轉(zhuǎn)塔式磨頭，裝有三根砂輪芯軸，可配9片砂輪一磨軸馬達(dá)功率15KW一數(shù)字控制一磨軸轉(zhuǎn)速2,000-8,000rpm一工件頭直接驅(qū)動(dòng)，轉(zhuǎn)速600rpm(可選)自動(dòng)上料系統(tǒng)(可選)每個(gè)托盤最多可裝40把刀具工件參數(shù)：300mm250mm350mm一最大直徑一全磨制

5、最大直徑一全磨制最大切削刃長(zhǎng)七.實(shí)驗(yàn)報(bào)告1 .實(shí)驗(yàn)?zāi)康? .實(shí)驗(yàn)內(nèi)容3 .實(shí)驗(yàn)步驟4 .實(shí)驗(yàn)結(jié)果(1) 利用刀具設(shè)計(jì)加工CAD/CAM軟件系統(tǒng)NUMROTOplus完成相應(yīng)刀具的CAM設(shè)計(jì)(2) 利用uwn型五軸數(shù)控刀具磨床和棒料加工出所設(shè)計(jì)的刀具(3) 給出設(shè)計(jì)加工的鉆頭的測(cè)量角度5 .實(shí)驗(yàn)分析與總結(jié)(1) 分析所設(shè)計(jì)鉆頭結(jié)構(gòu)特點(diǎn)和刀具幾何參數(shù)對(duì)加工的影響；(2) 分析五軸數(shù)控磨床的工作原理以及砂輪的特性由哪些因素決定；(3) 分析切削液的種類及切削液的使用情況對(duì)磨削加工的影響；(4) 對(duì)本次實(shí)驗(yàn)的感想與建議；8 .建議建議大家在實(shí)驗(yàn)前做好準(zhǔn)備工作，在實(shí)驗(yàn)中每組同學(xué)可進(jìn)行分工，以提高實(shí)驗(yàn)效率

6、9 .附錄GrindingGeneralintroductionGrindingmeanscuttingwithgeometricallynotdefinededges.Therotatinggrindingbodiesarecomposedofboundabrasivegrainsandimbeddedpores,functioningas"chipchambers”兒Advantagesofgrinding* Highsurfacequalityofthegroundparts* Goodmachinabilityofhardanddifficulttomachinemateri

7、alsHightimegrindingvolume.Partially,similarvaluesasforplaningandturningarepossible.SurfacegrindingmachinesOnsurfacegrindingmachinesplanesurfacesaremachinedbytheperipheryorbythefaceofthegrindingwheel(figure).Therearedifferentkindsofmachines:oneexecutionwithhorizontalandverticalgrindingspindle,theothe

8、rwithlongandwithrotarytable.Longtablesaremeantforbiggerresp.longerworkingpieces.Roundorrotarytablesaresuitedforsmallerpieces.Smallerpiecesdonotneedthechangeofdirectionattheend.Thereforeacontinuousfeedmotionispossible.Ongrindingmachinesthetool(grindingwheel)iseffectingthecuttingmovement.Dependingonth

9、emachinetypeordesign,theplungeandthefeedmotionareeffectedeitherbytheworkingpieceorbythetool.SurfacecylindricalgrindingmachinesOnthesemachinestheworkingpieceismostlyclampedbetweenthecenters.Itgetsarotarymotion.Thecuttingmovementiseffectedbythegrindingwheel.Thegrindingwheelcanbefedfrombehindtotheworki

10、ngpiece.Longworkingpiecesrequirealongitudinalfeed(figure),whichismostlyeffectedbytheworkingpiece.Hereaslide(workingpieceslide)isrequired,whichcanbeadjustedtodifferentstrokelengths.Theworkingpiecetableisfixedontheslide.Machineswithahorizontalspindlearemostlyusedforperipherygrinding.Infigureyoucanseed

11、ifferentexamplesofuse.Verticalspindlesareoftenusedforfacegrinding.Onbothmachinetypestheslidesaremostlyhydraulicallyoperated.Hydraulicdrivesarevibrationfree,thefeedisinfinitelyvariable.Highqualityslideguidesandgoodlubricantconditionsontheguidesurfacesareveryimportantinordertoavoidthestick-slip-effect

12、.Alsoveryimportantaregoodspindlebearingassemblies.References/characteristicsofagrindingwheelOnfigure1(pagel)youcanseethebodyofagrindingwheel.Thefigureshowstheabrasivegrains,thebondingmaterialandthepores.Whenselectingthesuitablegrindingwheel,fivedecisionshavetobemade.1Abrasivematerial(chemicalcomposi

13、tionoftheabrasivegrain).Themostimportantabrasivematerialsare:corundumA,siliconcarbideC,boronnitrideBanddiamondD.Corundumsaremainlycomposedofaluminiumoxide(AI2O3).Youhavetodifferbetweenseveraldegreesofpurity.Normalcorundum:94.97H%AI2O3.specialfusedalumina:morethan99%AI203Coojndumsareforexamplesuitedf

14、orthegrindingoflongcuttingmaterials.Siliconcarbideisharder.Itissuitedforthegrindingofshortcuttingmaterialsasforexamplegrayiron,chillcasting,carbide.grabrrrtttri.|Mme30.702.Granulation(grainsize)8c36IGAInthestandarddesignationthegrainsizew12isspecifiedwithanumber,forex.80.141660170b0Itspecifiesthenum

15、berofmeshes(per20inch)241000ofafilterbywhichthegrainswere1200sortedout.3. Hardness(Resistanceofthegrainsagainstbreakingoutofthebonding).Aseverycuttingtooldoes-grainsaredullingafteracertaintime.Whenthewheelhardnessisselectedcorrectly,thedulledgrainbreaksoutduetothehigherloadingandallowstherefore,that

16、new,sharpgrainscanwork.Thematerialoftheworkingpiecehasabiginfluenceonthehardnessselection.Hereyouhavetoconsider:Hardmaterialsrequiresoftwheels,softmaterialsrequirehardwheels.Whenhardmaterialsaremachinedthegrainsaredulledearlierandhavetodisconnectearlierfromthebonding.Thehardness(oneletterforex."

17、;M')referstothestationarywheel.AecDwochEFG攵hrw«ichH1Jo<KWCKhLMNOmittrlPaRshenTuVwwhrhartXYZAu&ef&thartArtificialresin-Bondingscontactzone).Duringinternalgrindingthegrainischargedlessandreststhereforelongerinthebonding.Sothewheelseemsharder.Inthefollowingyoufindotherpossibilities,

18、howtoincreasetheactivehardness(precondition:theothermachiningdatastaythesame). settinganewgrindingwheel(duetothebiggerdiameter) increasingthecuttingspeed(chipsectiongetssmaller). reducingthecuttingdepth.Selection:Jotcommentforselection:Thecutterhasahardnessof61HRC.Hereyoushoulduseagrindingwheelsofte

19、rthanJot.Fortheselectionhowever,measureandformprecisionhavetobetakenintoconsideration.Softgrindingwheelswearoutfaster.Andsoitismorediffculttokeepthegivenformandmeasuretolerances.4. Structure(spaceportionofgrains,bondingmaterialandpores)1234567891011121314<一openstructure>Theporesarenecessaryasc

20、hipsections.Theirsizeandquantityhavealsoinfluenceonthehardness(seeabove).Awheelbeingtootightistoohardandhastoolowefficiency.Withawheelbeingtooopen,itmightbedifficultdogetacertainsurfacequality.Ascharacteristicforthestructureanumberisused.Selection:structure55. Bonding(material,whichbindsthegrains)Th

21、ebondingisalsoresponsibleforthehardnessandespeciallyfortheelasticityofthegrindingwheel.Thebondinghastoendureamechanicalandalsoaveryhighthermalloading.Inthefollowingtherearementioned2kindofbondinQCharacteristicsCeramicgoodhardnessgraduationpossibilities荻錠?Bondingsresistanceagainstwaterandoil也舞礁V*indi

22、fferencetohighheating,but您修浦擊 sensitivitytoimpacts muchmoreelasticthanceramicbondings(especiallyimportantforthingrindingwheels) Bytheelasticattitudethegrainsareprotectedagainstoverload.Selection:V(CeramicBonding)Thestandarddesignationofthechosengrindingwheelis:Grindingwheel。用69120*250*2576慶60內(nèi)5VChec

23、kanddressingofthegrindingwheels,rulesforpreventionofaccidentsDuringgrindingthedangerofaccidentsisveryhigh.Whenthegrindingwheelbreaks,thepartsflyingaroundmaycauseadeadlyaccident,iftheyarenotcaughtbyaprotectingdevice.Thefollowingrulesforpreventionofaccidentsarealsoincludingthefieldoffreeformgrinding,(

24、grindingofknifes,scissors,etc.) Beforedressingthegrindingwheelyouhavefirsttoeffectanacoustictest.Thewheelhastobekeptintheboreandisslightlyhitforex.withapieceofhardwood.Thesoundmustbehigh. Theflangesmusthavethecorrectsize(S>1/3Dwhenusingprotectivecaps.S=2/3Dwithoutprotectivecaps,S=112Dforconicalwh

25、eels.Theflangesmusthavethesamesize.Youmustputintermediatelayersoutofelasticmaterialbetweentheabrasivewheelsandthedampingflanges(forex.rubberorfelt).Thusirregularitiesonthegrindingwheelsurfaceshallbecompensated Thegrindingwheelmustbeeasytosliponthespindle.Whenyouhavesimplegrindingmachines,theworkrest

26、shavetobeputclosetothegrindingwheelandhavetobereadjustedregularly. Pleasepayattentiontothemaximumrotationfrequency.Onthegrindingwheelyoucanseethemaximumallowableperipheralspeed,forexonabluestripe(blue:vc<45m/s). Beforethefirststartpleasetakecarethatnotoolsorotherthingsmaybeacquiredbythegrindingwh

27、eel.eAftereachnewsettingyouhavetoeffectatestrunningofatleastfiveminuteswiththeratedmaximumrotatingfrequency. Duringgrindingyouhavetowearprotectivegoggles.BalancingDuringgrindingyouworkwithhighperipheralspeedsandthereforealsowithhighrotatingfrequencies.Whenusingunbalancedgrindingwheels,youhavetoexpec

28、tunbalanceandthecorrespondingcentrifugalforce.Unbalancedgrindingwheelscausevibrations,whichmayimpairthesurfacequalityandreducethelifeenduranceofthegrindingwheelandthemachine.I.SHUFlarth-HjITi/ZwischecMer.rSAACKEWorkshopGrindingThegrindingwheelshavetobebalancedtogetherwiththeirflanges.Inmanycasesstat

29、icbalancingwithcompensationmassesissufficient.Thegrindingwheelsatisfiesineachpositionthemasspoint.Iftherearehighdemandsresp.verylargewheels,youhavetobalancedynamically.CylindricalgrindingsurfacecylindricalgrindingThestud025mmofthebevelpinionhasalengthof20,3mm.Ifyouhaveagrindingwheelwidthof25mmitispo

30、ssibletofinishthediameterwithoneplunge-cutThisworkingmethodiscalledcrossgrinding.Duetotheshortproductioncycleitisveryeconomical.Aftergrindingthediameter,theendfacehastobemachined.Thisprocessiseffectedwiththefrontfaceofthegrindingwieel.Bybevelingitispossibletomachinebothsurfacesinthesametimewithonepl

31、unge-cut.Wfilegrindingiseffected.Withthismethodacertaincontouriscompletedbyoneplunge-cut.Forlongerpartsyouneedeitheralongitudinalfeed(swinggrinding)orseveralplunge-cutsareplacedsidebyside.Thefirstpossibilityyoufindmoreoften,forexbecausebythismethodyoucanreachacontinu

32、ouschipremoval,theproductiontimeisreduced.Fortheswinggrindingthegrindingwheelhastohavealittleoverrun(1/3to1/4ofthewheelwidth).Ifnot,attheendsitwillnotbepolishedenough.Forthebearingdiameter40mmofthedrivegearwheelthefollowingshiftisnecessary:L=L+1Z3*BL:shiftlengthI:pinlengthattheL=54mm+1/3*25mmworkpie

33、ce(54mm)L«63mmB:grindingwheel-width(25mm)Duringgrindingthegrindingwheelmaybeapproachedverysensitively,Uiescaledivisionvalueamountsmostlyto1pm.Forautomaticapproachamargin(byamechanicaldevice)ispossible.However,afterdeactivationofthefeedthewheelcontinuesgrinding"outsparking".Thatwayther

34、espectofthemeasuretolerancesisverydifficult.Ameasurecontrolterminatesthegrindingprocessassoonastherequiredmeasureisreached.Centerlesssurfacecylindricalgrinding.Thespecialtyofthismethodisthattheworkpieceisnotfixedinaclampingdevice,butliesfreeonahardrest.Aregulatingwheelsupportstheworkpiece,inthesamet

35、imethewheeltransfersitsperipheralspeedontheworkpieceandenablessothegrindingprocess.PlaneorsurfacegrindingForthegrindingofplanesurfacesthereexistparallelstomilling.Howevertheconsiderationsofthemillingcannotsimplybetransferred,becausethetoolhasanotherstructureandbecauseyouworkwithotherspeeds.Duringthe

36、facegrindingthereisabigcontactareabetweenthegrindingwheelandtheworkpiecesurface.Therearethefollowingdangers:Intenseheatgeneration(duetothebigcontactarea).Forhardenedpiecesthestarttemperaturecanbeexceededlocally.Thatmeans:softareasaregenerated.Onaclosedfrontfacethechipsandalsothebrokenoutgrainshavedi

37、fficultiestocomeout.Thewheelcanbeclosedfromthechips.Possiblecountermeasuresarethefollowing:2XnncmsATbMStur3TdUfirftw.twScZrfM'Eon21Wcrk/rjucn4/yHdKhondgg5SdzDiscontinuitiesinthegrindingwheels(forex.segmentalwheels).Insomecasesitispossibletoinclinethespindle.Herebyhoweverthereareformdeviationsatthewxkpiece.Themachiningofthediscontinuedsurfacesisfavorable.Herebythegrainsagainandagainhitfreespaces,wherethechipsarekickedoffandwhereisnofriction.Alsothesingleedgescanere-touch".Duringperipherygrindingthecontactareabetweengrindingwheelandworkpieceisre