Nto tiav hauv CNC Milling Kev Ua Haujlwm
1. Hom Nto Roughness Achievable
CNC milling ua rau ntau qhov chaw tiav nyob ntawm cov cuab yeej siv, tshuab dynamics, thiab cov khoom siv. Rough milling rau kev tshem tawm cov ntaub ntawv feem ntau ua tiav nto roughness ntawm 3.2 thiab 12.5 micrometers Ra, yam ntxwv los ntawm cov cuab yeej tseem ceeb thiab cov npoo scalloped los ntawm cov kauj ruam loj. Semi- ua tiav milling nrog cov tsis muaj qhov nruab nrab yields 1.6 mus rau 3.2 micrometers Ra, haum rau tsis yog - cov yam ntxwv tseem ceeb. Ua kom tiav milling siv cov txheej txheem zoo, siab ntxaiv ceev, thiab cov cuab yeej ntse ncav cuag 0.8 txog 1.6 micrometers Ra, tsim nyog rau kev sib dhos dav dav. Fine finish milling nrog optimized siab -kev ceev machining tswv yim ua tiav 0.4 mus rau 0.8 micrometers Ra, tsim nyog rau pom qhov chaw kom zoo nkauj thiab nruab nrab-precision fits. Siab- precision milling siv cov tshuab nruj, sib npaug cov cuab yeej, thiab micro- kauj ruam dhau los tuaj yeem ncav cuag 0.2 txog 0.4 micrometers Ra. Ultra- precision milling nrog tshwj xeeb spindles, kev sib cais ntawm kev vibration, thiab ib leeg - siv lead ua pob zeb diamond los yog polished carbide cov cuab yeej tsim daim iav-zoo li qhov chaw hauv qab 0.1 micrometers Ra, nrog rau kev siv micromachining tshwj xeeb mus txog 0.05 micrometers.
2. Theoretical Foundation ntawm Milled Surface Generation
Tsis zoo li tig qhov twg ib qho - cov cuab yeej taw tes tsim cov helical nto txuas ntxiv, milling siv ntau - cov hniav cutters uas tsim cov qauv tsis tu ncua, cycloidal nto. Lub ncov theoretical - txog - hav qhov siab nyob rau hauv peripheral milling nyob ntawm cutter txoj kab uas hla, tus naj npawb ntawm flutes, pub rau ib tug hniav, thiab radial kev koom tes. Rau pob- xaus milling ntawm peb- qhov chaw seem, cusp qhov siab ntawm qhov uas nyob ib sab hla dhau raws geometric kev sib raug zoo nrog cov cuab yeej vojvoog thiab stepover nrug. Txo cov kauj ruam dhau los ntawm 0.5 millimeter mus rau 0.1 millimeter feem ntau txo qis qhov siab ntawm qhov siab los ntawm ib qho ntawm tsib, tab sis qhov kev txhim kho tiag tiag yuav ploj mus vim lub tshuab muaj zog thiab cov cuab yeej deflection txwv.
Qhov sib cuam tshuam ntawm kev txiav qhov ntawm milling qhia txog lub sijhawm cuam tshuam rau lub zog uas ua rau muaj kev cuam tshuam ntawm cov qauv kev co, ua rau qhov ua tiav tiav ntau dua rau kev ua haujlwm zoo dua li cov txheej txheem txiav txuas ntxiv. Txhua lub tshuab raj nkag ua rau lub sijhawm hloov pauv lub zog uas tuaj yeem ua rau muaj kev sib tham yog tias muaj ntau zaus ua ke nrog cov qauv tsim qauv.
3. Qhov tseem ceeb Parameter cuam tshuam rau Milled nto tiav
Pub rau ib tug hniav ua hauj lwm raws li qhov tseem ceeb parameter cuam tshuam qhov zoo nkauj nto. Cov khoom noj qis dua txo cov nti tuab thiab theoretical scallop qhov siab, txhim kho kev ua tiav ntawm tus nqi ncua sij hawm. Txawm li cas los xij, cov khoom noj uas tsis tshua muaj ntau dhau ua rau rub tawm es tsis yog shearing, ua kom sov thiab ua haujlwm - hardening yam tsis muaj kev txhim kho kom tiav. Qhov zoo tshaj plaws pub rau kev ua tiav feem ntau yog li ntawm 0.05 mus rau 0.15 millimeters ib tus hniav rau cov hlau, thiab 0.1 mus rau 0.3 millimeters ib tus hniav rau txhuas, nrog kev ua tiav hauv qab 0.05 millimeters ib tus hniav.
Kev txiav ceev cuam tshuam rau kev ua tiav los ntawm kev tsim- tus cwj pwm ntawm ntug kev, kev hnav cov cuab yeej, thiab cov teebmeem thermal. Kev nrawm dua feem ntau txo qis ua - nce ntug hauv txhuas thiab tooj liab, txhim kho qhov ci ntsa iab. Hauv cov hlau, qhov nruab nrab ceev sib npaug ua tau- nce ntug kev tiv thaiv tawm tsam kub dhau heev uas ua rau cov crater hnav. Kev nrawm dhau ntawm txhua yam khoom tsim kev co thiab thermal distortion uas degrade tiav qhov sib xws.
Radial kev koom tes los yog stepover critically txiav txim siab tsim nto nyob rau hauv profiling thiab pocketing ua hauj lwm. Loj stepovers ntawm 50 mus rau 80 feem pua ntawm txoj kab uas hla cutter maximize cov khoom tshem tawm tab sis tsim cov scallops tseem ceeb. Kev ua tiav zoo siv 5 mus rau 15 feem pua ntawm cov kauj ruam kom txo qis qhov siab thiab qhov waviness. Adaptive clearing strategies tswj cov kev sib koom ua ke tsis tu ncua, tiv thaiv kev quab yuam spikes uas ua rau kev sib tham thiab qhov sib txawv.
Axial qhov tob ntawm kev txiav cuam tshuam tiav los ntawm nws cov txiaj ntsig ntawm qhov system deflection thiab kev sib tham nyiam. Sib sib zog nqus axial engagements ua rau cov cuab yeej overhang cuam tshuam thiab vibration susceptibility. Rau kev ua tiav zoo, axial qhov tob yuav tsum tau txwv rau ib mus rau ob npaug ntawm cov cuab yeej txoj kab uas hla rau qhov kawg mills, nrog rau qhov tob tob tob rau ntev - mus txog daim ntawv thov.
4. Cov cuab yeej Geometry thiab cov khoom xaiv
End zeb geometry profoundly cuam tshuam milled nto zoo. Helix lub kaum sab xis cuam tshuam txiav quab yuam kev taw qhia thiab nti khiav tawm. Lub kaum sab xis siab ntawm 45 degrees los yog ntau dua tsim cov kev txiav tawm sab saud uas txhim kho kev ruaj ntseg rau nyias - phab ntsa machining thiab txo cov kab nrib pleb. Lub kaum sab xis qis ntawm 30 degrees muab lub zog ntug ntau dua rau qhov hnyav roughing tab sis tsim rougher tiav. Qhov sib txawv ntawm helix thiab cov suab sib txawv tsim los cuam tshuam kev sib tham sib tham los ntawm kev tiv thaiv kev sib raug zoo ntawm theem kev sib raug zoo ntawm cov raj nplaim txuas ntxiv, ua kom muaj kev ruaj khov dua qhov tob thiab txhim kho qhov zoo nkauj.
Lub kaum sab xis ntawm lub voj voog thiab pob-kawg geometry txiav txim siab tsim nto hauv peb -axis thiab tsib-axis profileing. Lub kaum ntse ntse kawg mills tsim cov cuab yeej sib txawv ntawm kev hloov pauv. Lub kaum sab xis ntawm 0.5 mus rau 2.0 millimeters ntxiv dag zog rau lub cuab yeej thiab txo cov kev ntxhov siab thaum tswj geometric txhais. Pob-kawg mills nrog radii matched rau saum npoo curvature txo cusp qhov siab nyob rau hauv complex profileing.
Cov cuab yeej siv thiab cov txheej txheej xaiv sib npaug ntawm ntug ntse tiv thaiv hnav tsis kam. Uncoated micro-grain carbide muab qhov siab tshaj plaws ntawm ntug rau txhuas thiab tsis yog -ferrous xov. Titanium aluminium nitride coatings txuas ntxiv lub neej ntawm cov hlau thiab siab -kub alloys tab sis tej zaum yuav nce lub vojvoog me ntsis. Pob zeb diamond coatings haum cov ntaub ntawv abrasive xws li graphite thiab siab -silicon aluminium. Polycrystalline pob zeb diamond thiab cubic boron nitride cov cuab yeej pab tau ultra-precision tiav nyob rau hauv non-ferrous thiab hardened cov ntaub ntawv feem.
Cov cuab yeej kho mob ua pov thawj tseem ceeb rau kev ua tiav zoo ib yam. Cov cuab yeej hnav txhim kho ntug sib dhos, hnav flank, thiab chipping uas ua rau kom muaj zog txiav thiab tsim cov khoom tawg. Kev tshuaj xyuas tsis tu ncua thiab kev hloov pauv raws li kev tshem tawm cov khoom siv los yog saib xyuas cov av dav dav khaws cov peev txheej tiav.
5. Tshuab Dynamics thiab ruaj khov
Tshuab rigidity fundamentally constrains ua tiav milling tiav. Spindle bearing mob, axis tsav rigidity, thiab thav duab structural kev ncaj ncees txiav txim siab lub cev tiv thaiv kev co. Ntau dhau spindle runout txhais ncaj qha rau hauv qhov profile variation, nrog rau txhua lub tshuab raj txiav ntawm me ntsis radii sib txawv. Axis backlash thiab servo mismatch tsim quadrant glitches thiab nto blemishes ntawm kev taw qhia reversals.
Chatter sawv cev rau thawj dynamic txwv ntawm milled nto tiav. Tus kheej-Zoo siab vibration tshwm sim los ntawm cov teebmeem regenerative tsim cov qauv waviness tsis tu ncua uas rhuav tshem qhov tseeb. Cov tswv yim tiv thaiv kev sib tham muaj xws li xaiv qhov ruaj khov nrawm los ntawm daim duab lobe, siv cov cuab yeej suab sib txawv los cuam tshuam cov kev tawm tswv yim rov qab, ua kom lub cev muaj zog los ntawm cov cuab yeej luv dua lossis txhim kho kev ua haujlwm, thiab siv cov khoom loj dampers lossis kev co tswj kev ua haujlwm rau cov ntawv thov tseem ceeb.
Thermal stability cuam tshuam ua tiav los ntawm qhov ntev drift thaum lub sijhawm ua haujlwm txuas ntxiv. Spindle thermal kev loj hlob hloov cov cuab yeej txoj hauj lwm, tsim cov phab ntsa tapered los yog dimensional variation. Tshuab sov-txog cov txheej txheem, ntxaiv cua txias tshuab, thiab kub-tswj ib puag ncig txo cov thermal cuam tshuam rau kev ua tiav tiav.
6. Kev txiav txim siab ntawm cov khoom siv ua haujlwm
Cov khoom siv tsim cov txheej txheem tiav rau kev milling. Aluminium alloys tshuab tau yooj yim nrog lub ntsej muag zoo nkauj, niaj hnub ua tiav 0.4 txog 0.8 micrometers Ra nyob rau hauv tiav dhau thiab qis dua 0.2 micrometers nrog optimized tsis. Cam khwb cia txhuas nrog cov ntsiab lus siab silicon nthuav tawm tus cwj pwm abrasive uas ua kom cov cuab yeej hnav thiab txwv kev ua tiav zoo. tooj liab thiab tooj dag muab tshwj xeeb machinability thiab tuaj yeem ua tiav daim iav tiav nrog cov cuab yeej pob zeb diamond.
Steels nthuav dav variation nyob rau hauv milling teb. Tsawg- cov pa roj carbon steel zoo li ua rau tsim- nce ntug tsim ntawm qhov nrawm nrawm, yuav tsum tau ua kom siab txiav tsis zoo lossis txhim kho lubrication. Nruab nrab-carbon thiab alloy steels tshuab kom zoo tiav nrog cov cuab yeej coated carbide. Hardened steels saum toj no 45 HRC yuav tsum tau txo qhov ceev, tshwj xeeb coatings, los yog cubic boron nitride tooling kom ua tiav qhov kev ntxhib los mos.
Cov hlau tsis muaj steel, tshwj xeeb tshaj yog qib austenitic, ua haujlwm- tawv sai thiab ua kom kub txiav siab. Kev ua tiav zoo hauv qab 1.0 micrometer Ra xav tau qhov zoo tshaj plaws- cov cuab yeej rake, tsis zoo ib yam kom tsis txhob ua haujlwm- cov txheej tawv tawv, thiab feem ntau cryogenic lossis siab - cov cua txias los tswj cov teebmeem thermal.
Titanium alloys tam sim no loj milling cov nyom vim tsis zoo thermal conductivity, tshuaj reactivity, thiab tsis tshua muaj elastic modulus. Txiav kub concentrates ntawm lub cuab tam ntug, accelerating diffusion hnav. Qhov saum npoo tiav feem ntau yog li ntawm 1.6 txog 3.2 micrometers Ra nrog cov qauv zoo sib xws, nrog cov tswv yim tshwj xeeb ncav cuag 0.8 micrometers.
7. Tool Path Strategy thiab Programming
Cov cuab yeej txoj kev geometry ho cuam tshuam qhov chaw tiav dhau qhov kev xaiv yooj yim. Pa raster milling nrog bidirectional passes tsim cov qauv kev taw qhia saum npoo thiab tej zaum yuav qhia cov neeg tim khawv ntawm cov ntsiab lus tig. Cov cuab yeej kev sib koom ua ke tsis tu ncua xws li trochoidal milling, hloov kho kom haum, thiab siab - kev ua haujlwm zoo milling tswj cov kev txiav kom ruaj khov, txhim kho qhov zoo nkauj ntawm lub cev thiab lub neej cuab yeej.
Rau peb - qhov chaw seem, qhov kev taw qhia stepover txheeb ze rau qhov curvature deg cuam tshuam rau cusp geometry. Machining raws tus thawj curvature cov lus qhia minimizes geometric approximation yuam kev. Tsib -axis ib txhij milling orients cov cuab yeej ib txwm rau saum npoo, tswj kev sib koom ua ke thiab ua kom siv lub pob loj dua -kawg radii rau txo qhov siab cusp.
Kev nkag mus thiab tawm cov tswv yim tiv thaiv cov blemishes. Ramping los yog helical nkag tsis txhob plunge marks. Cov hlau lead du -hauv thiab coj- tawm arcs tshem tawm cov kab nyob ntawm kev txiav ciam teb. Kev tuav tus nqi noj tas mus li los ntawm cov ces kaum tiv thaiv kev nrawm dua - cov qhab nia qis los ntawm kev txwv servo teb.
8. Coolant thiab Chip Management
Kev khiav tawm ntawm cov nti zoo tiv thaiv kev txiav, qhov uas cov chips daig tau rov ua dua - tshuab, ua kom muaj cua sov ntau dhau thiab qhov kev puas tsuaj uas tsis tuaj yeem pom. Siab -siab coolant ntawm 70 mus rau 150 bar blasts chips los ntawm cov hnab ris thiab cov yam ntxwv sib sib zog nqus. Los ntawm -spindle coolant kom ntseeg tau tias xa mus rau qhov txiav ntug txawm nyob rau hauv cov geometry. Cua moj tej tawg los yog tsawg kawg kom muaj nuj nqis lubrication tej zaum yuav nyiam rau txhuas los tiv thaiv thermal shock thiab coolant residue staining.
Coolant kub tswj tswj thermal stability. Dej nyab lub coolant yuav tsum tau khaws cia ntawm 20 degrees Celsius ntxiv lossis rho tawm 2 degrees kom tsis txhob muaj qhov sib txawv. Qhov txias txias ntau dhau ua rau cov khoom ua haujlwm sib cog lus thaum lub sijhawm ua haujlwm thiab nthuav dav tom qab ntsuas, ua kom pom tseeb qhov tsis raug.
9. Cov txheej txheem milling tshwj xeeb rau kev ua tiav tiav
High -Machining ceev siv spindle speeds ntawm 20,000 mus rau 60,000 revolutions ib feeb lossis siab dua nrog cov nqi pub noj ntxiv. Qhov txo nti load rau ib tus hniav thiab nce kev txiav ntau zaus ua kom zoo dua nto textures thiab pab kom machining ntawm nyias nta nrog tsawg deflection. Micro-milling siv cov cuab yeej hauv qab 0.5 millimeter txoj kab uas hla ua tiav cov yam ntxwv zoo thiab ua tiav hauv cov khoom me me, txawm hais tias spindle runout thiab cov cuab yeej tawg tam sim no muaj teeb meem loj.
Hard milling machines hardened steels mus txog 65 HRC siv cubic boron nitride lossis coated carbide cov cuab yeej, ua tiav ntawm 0.4 txog 0.8 micrometers Ra thiab muaj peev xwm tshem tawm kev sib tsoo. Kev vibration-pab milling superimposes ultrasonic lossis qis- zaus oscillation ntawm cov cuab yeej ua haujlwm ib txwm ua, hloov cov chip tsim thiab txo cov txiav quab yuam kom txhim kho qhov chaw ruaj khov hauv cov ntaub ntawv nyuaj.
10. Kev Ntsuas thiab Kev Tswj Xyuas Zoo
Milled nto tiav kev ntsuas feem ntau ntiav hu rau stylus profileometers tracing perpendicular rau cov cim tseem ceeb. Rau peb - qhov chaw seem, kev ntsuas kev taw qhia yuav tsum ua raws li cov kauj ruam dhau los txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau nws qhov yuav Dawb lub teeb interferometry thiab confocal microscopy muab tsis yog -kev soj ntsuam rau cov chaw mos lossis sub-micrometer roughness yuav tsum.
Kev ntsuas qhov chaw yuav tsum zam qhov chaw nkag thiab tawm, kev hloov pauv ntawm cov cuab yeej, thiab thaj chaw ntawm kev sib tham pom tseeb lossis kev sib koom ua ke ntawm cov cuab yeej sib txawv. Ntau qhov kev ntsuas thoob plaws saum npoo ua tus yam ntxwv sib xws thiab txheeb xyuas cov qauv txheej txheem ntsig txog lub tshuab geometry lossis cov cuab yeej hnav kev ua tiav.
11. Kev daws teeb meem kev ua tiav tag nrho
Scallop marks coarser tshaj qhov kev kwv yees kwv yees qhia tau hais tias dhau mus dhau, cov cuab yeej deflection hauv kev txiav quab yuam, lossis kev ua raws li tshuab. Ua tau - nce ntug manifests li torn, irregular deg zoo nkauj nrog cov ntaub ntawv deposits, yuav tsum tau nce ceev, txhim kho coolant, los yog sharper tooling. Chatter tsim cov waviness tsis tu ncua perpendicular mus rau kev coj noj coj ua, yuav tsum tau hloov ceev, nce rigidity, los yog cov cuab yeej suab sib txawv. Quartering lossis tim khawv cov cim ntawm cov kev hloov pauv qhia txog servo mismatch lossis kev txwv nrawm, yuav tsum tau pub tus nqi noj zaub mov zoo lossis kev hloov pauv yooj yim. Nto tearing nyob rau hauv cov ntaub ntawv ductile tshwm sim los ntawm tsis zoo rake ces kaum, dull cov cuab yeej, los yog tsis txaus txiav ceev. Burr tsim raws cov npoo qhia tias tsis tsim nyog tawm tswv yim, pub ntau dhau, lossis tsis txaus cov cuab yeej ntse.
Xaus
CNC milling ua tiav qhov kawg ntawm qhov kawg ntawm kev tshem tawm cov khoom ntxhib ntawm 12.5 micrometers Ra mus rau ultra- qhov tseeb daim iav nto hauv qab 0.1 micrometers Ra. Qhov ua tiav tiav yog nyob ntawm qhov kev sib xyaw ua kom zoo ntawm kev txiav cov cuab yeej, cov cuab yeej geometry thiab cov khoom siv, tshuab dynamics, cuab yeej txoj kev zoo, kev xa khoom txias, thiab cov yam ntxwv ntawm cov khoom ua haujlwm. Qhov sib cuam tshuam ntawm kev txiav ntawm milling qhia txog cov kev sib tw tshwj xeeb los ntawm kev co thiab kev sib tham uas xav tau kev saib xyuas tshwj xeeb rau qhov system stability. Rau cov ntawv thov precision hauv kev tsim pwm, cov khoom siv hauv aerospace, thiab cov khoom siv kho qhov muag, kev nqis peev hauv siab - nrawm spindles, vibration- damped tooling, thermal stability, thiab qib siab CAM cov tswv yim tsis tu ncua muab qhov zoo tshaj plaws ntawm kev ncaj ncees. Kev nkag siab txog cov txheej txheem theoretical ntawm milled nto tiam ua ke nrog cov tswv yim kev paub ntawm lub tshuab dynamics ua rau cov txheej txheem engineers thawb cov ciam teb ntawm milling precision thaum tswj cov khoom tsim tawm cov nqi.
