Kev Test Qhov Tseem Ceeb Kawg Txog Qhov Chaw
Laser interferometry muab qhov tseem ceeb kawg rau kev test cov ntsiab lus tseem ceeb, uas yog qhov tseem ceeb tiam siab rau kev lag luam calibration. Yog tias siv tsis tau kev sib txig, nws muab kev hloov pauv ntev, kev nyiaj, kev ncua, thiab kev ncua raj dej nrog qhov tseem ceeb—tseem ceeb rau kev lag luam CNC tshaj tawv.
Kev Nyiaj, Kev Ncua, thiab Kev Ncua Raj Dej Nrog Laser Interferometry
Laser interferometers tsim kev siv los ntsuas tias yam dab neeg hloov mus li cas hauv qab no peb lub teeb meem - X, Y thiab Z. Lawv ua li no los ntawm kev saib seb dab tib siab thaum laser beams raug chav tawm thiab tom qab ntawd raug sib tshooj rau kev. Thaum sau ntev kom dhau los ntawm kev saib xyuas seb yam twg yog kab raj kab rai, cov khoom siv optical tshwj xeeb saib xyuas tias txoj kev nyob ib leeg zoo li cas nyob nruab nrab ntawm qhov sib txawv ntawm axes. Txhua yam leej leej muaj feem nyob no. Yog tias muaj dab tsi li 5 arc seconds uas tsis nyob ib leeg tuaj yeem pab tau kev pheej hmoo sib npaug nrog 0.01 mm tom qab hloov 200 mm. Sau ntev kom paub seb puas yog txhua yam axes ntawm lub tshuab no nyob ib leeg kab raj kab rai kuj tseem tseem ceeb vim tias cov ntsaws leej no sib cuag thiab sib tshooj rau kev nrog rau daim duab tseem ceeb hauv cov khoom tsov khoom peb tsim. Nrhiav cov ntsiab lus no nyob ib leeg yog tseem ceeb heev rau kev tsim kho tshuab CNC uas txhua yam yuav tsum nyob ib leeg hauv kev ncua deb tshaj tawv, thaum tib neeg ib txwm zoo dua li plus lossis minus 0.005 mm.
Spindle Runout thiab Thermal Drift Sau Ntev rau Hauv Loads CNC Machining Siv Kev Tsim Khoom
Kev ntsuas qhov tsis raug hauv qab thiab hauv sab nraud ntawm spindle siv probes capacitance thaum ua haujlwm nyob rau hauv RPM. Kev txiav tso tawm thermal yog sau los ntawm kev sau spindle nyob rau hauv 80% zog rau tib si saib xyuas rau ib cheem kheej, muaj sensors kuaj xyuas kev phom sij thermal. Cov pom zoo tseem ceeb yog:
| Parameter | IMPACT | Txoj kev kho kom raug |
|---|---|---|
| Qhov ntsuas hauv sab nraud > 3 μm | Qhov tool deflection ua rau muaj qhov tsis raug hauv dimensions | Kev rhuab nrhab kev hloov pauv tool hauv kev ua lej |
| Qhov axial play > 2 μm | Qhov surface finish txo siab | Kev lag luam calibration |
| Thermal growth > 15 μm/m | Qhov tshwm sim thaum ua haujlwm ntev | Kev kompenset thermal hauv xov tooj |
Cov kev sib txig sib xaus thermal tsis raug kho tsoom rau 40% ntawm cov ntaub ntawv muaj qhov loj me me nyob rau hauv cov khoom siv titanium nyob rau hauv av ( Tseg Ntawv Kawm Txuj Ci 2023 ). Sib sau nrog cov ntaub ntawv thermal drift rau hauv cov chav kho kom tau vim muaj kev nce ntau hauv qhov sib ntxiv ntev.
Kev ntsia xyuas thiab kev rov qab los daim ntawv pov thawj nyob hauv qhov chaw
Kev ntsia xyuas kev ntsia xyuas los ntawm Laser Interferometer rawy li ISO 230-2 (Muab tsham tom qab kev khov koj)
Kev siv laser interferometry kom nrhiav xyuas qhov teeb meem ntawm kev txiav txim siab ntawm kev sib txig nrog qhov tseem ceeb hauv micrometer raws li ISO 230-2, uas yog qhov tshwm sim rau peb paub yog tias peb cov CNC machines puas muaj qhov tseem ceeb txaus rau kev rov cuab. Thaum kuaj xyuas cov displacement tsuas li no, peb kuj saib xyuas hauv qhov keev caij ces muaj nyob hauv cheeb tsam, tshpecially yam thermal effects uas tsuas muaj ib qho kawg siab dua los sis dua li 2 degrees Celsius tuaj yeem ua rau muaj qhov error rate nyob rau 0.01 mm per meter. Kev tau kom muaj ib qho bidirectional compensation zoo yooj yim yog tshua tshua tshua, vim nws pab kho qhov reversal errors uas muaj los ntawm mechanical backlash uas yuav ua rau muaj kev sib txawv txog 15 micrometers hauv kev ua haujlwm me me. Thaum cov ntsiab lus hloov mus hloov los ntawm lub path uas tau raug program lawm, lub system sau sov tag nrho qhov sib txawv ntawm yam uas tau raug command thiab yam uas tshwm nyob hauv lub shop floor. Cov kev kuaj no pab tswj cov error compensation tables uas tau tsim hauv lub CNC controllers tus kheej. Qhov tshwm sim? Lub machine nyiam qhov tseem ceeb ntawm nws, thaum nws nyob hauv kev ua haujlwm ntau axis ntau hnub hnub.
Kevvam ntsuab lus rau kev txhpluas ntawm kab roj thiab kev nyiam xeeb ntawm servo loop hauv kev sau ua CNC tsim nyog
Kev test ballbar soj kom paub txog qhov tseem ceeb ntawm kev sib piv kab roj thiab kev ua haujlwm ntawm servo loop thaum cov contour dynamic, sim cov duab tshwm tam sim thaum sau ua CNC tsim nyog. Qhov chav siv sib ntxiv spindle rau cov dining table, hloov qhov deviation radial thaum chav siv sau kab roj tswv yim nyob rau qhov sib txawv feed rates. Cov metrics tseem ceeb muaj:
- Qhov error ntawm circularity : Qhov deviation uas loj dua 40 μm sau tias muaj qhov taw tes lossis muaj teeb meem squareness
- Qhov tsis sib xws ntawm servo : Sau tias axis tsis sib cuam tshuam zoo, feem ntau pom los ntawm cov duab oval
- Qhov sensitivity ntawm feedrate : Qhia tias muaj kev vibration nyob rau hauv qhov ntev tshaj 8 m/min
Qhov tsis txaus ntseeg hauv qhov chaw nruab nrab tuaj yeem pom tau cov khaub ncaws siv lossis cov teeb meem lub lubrication ua ntej thaum lawv tsis tuaj yeem ua rau muaj kev phom sij rau qhov khoom. Rau cov kev sib tov 3D, cov kev sim raug ua hauv ntau lub teb chaws kom paub tias kev ua haujlwm zoo ib yam. Qhov kev kho kom sib xws no cuam tshuav rau qhov chaw nruab nrab los txo qhov tsis txaus thiab qhov loj me me los ntawm 70%, uas pab tso caij ntau rau kev ntxiv qhov chaw nyob rau hauv cov khoom siv tseem ceeb.
Kev daws teeb meem nyob hauv kev tsim kho nyob hauv cheeb tsam nrog rau cov khoom sim standard
NAS 979 thiab ISO 10791-6 Kev Sim Khib: Sib sau ua ke kev ntsuas tseem ceeb rau kev ntsuas pov tseg, kev ntsuas qhov loj me me, thiab qhov tsis txaus hauv kev tsim kho CNC nyob rau hauv cheeb tsam
Cov kev tshawb fwm los ntawm NAS 979 thiab ISO 10791-6 txhawj xeeb rau kev sib txuas ntev nres hauv laboratory thiab cov lej nres nyob rau hauv chaw tsim khoom. Cov kev tshawb fwm feem ntau yuav tsum sau ua rau ob npaug, xim ncav, thiab lub cav muaj ntau qhov rooj kom pom tias tus chaw tsim khoom muaj kev nruj siab li cas los tsim tau cov khoom zoo. Xa mus rau kev tsim khoom hauv daim meej taw tes li, cov chaw tsim khoom uas nyob hauv 0.005mm ntawm qhov chaw muaj peev xwm tsim tau cov ntim siab tshaj 0.8 microns. Qhov sib cuag no muaj txiaj ntsig tshaj plaws thaum tsim cov khoom uas xneed kev nruj siab thiab xim zoo.
| Qhab neeg Muaj Cuab yeej | Kev Sib Zais Kev Lag Luam | Kev Nruj Siab Hauv Daim Meej Taw Tes |
|---|---|---|
| Ntim Siab (Ra) | ≦ 250 μin | ≦ 32 μin |
| Kev Raug Zoo | ±0.13 mm | ±0.005 mm |
| Txoj Cai Tsis Raug (Kev Nyiag) | 0.1 mm/m | 0.01 mm/m |
Ua haujlwm rau cov leej num, thaum cov ntsiab lus sib xyaw ua rau muaj qhov tsis zoo dua 15 microns saum ib degrees Celsius, qhov no yuav tshwm sim rau cov ntsiab lus tsis zoo hauv cov khoom muaj kab nrov. Tas li, kom servo lag nyav ntawm 0.001 seconds tuaj yeem cuam tshuaj rau qhov tsis yog hluas los ntawm 40% raws li cov kev suav ntxiv tau piav hais nyob rau lub sijhawm no. Cov chaw tsim khoom uas txuas ntxiv cov kev pib no feem ntau yuav hloov kho lawv cov kev them, kho cov taw tes, thiab kho kom raug rau cov kev kho kom raug ua vor tshwm sim. Txhawj xeeb tshaj plaws yog tias kawg zuj zus 92% ntawm cov chaw tsim khoom muaj precision tau mus nruj lawm rau qhov no raws li tau hais hauv Manufacturing Tech Review nyob rau xyoo las. Txawm tsis yog txhua chaw tsim khoom xav tau qhov no, tab sis rau cov uas tsim khoom nrog cov ntsiab lus me me, kom tau cov ntsiab lus no raug yuav pab tau rau cov chaw tsim khoom ua kom zoo tom qab tuaj yeem ua haujlwm ntau tshaj plaws tsis tas txhob poob siab.
Sau cov ntaub ntawv thaj tsam precision rau hauv kev khoob cua rau CNC
Thaum cov ntaub ntawv tshawb nrhiav meej meej siv hauv kev them nyiaj qhov chaw tsim khoom CNC, nws pib muab kev pab tshwm sim rau hauv chaw tsim khoom. Xaiv kev sib piv laser interferometry nrog kev soj ntsuam kub thiab txias - ob yam no rau kev pab khoov cuab xyuas khoov cuab ua ntej kom tsis txhob muaj kev sib txawv thaum kho tiam. Cov ntaub ntawv ballbar sau tias muaj teeb meem nyreg siab, yog li CAM programmers yuav hloov pauv kev ntu ncua kom raug, uas tso cai kom tsis txhob muaj kev hloov meej meej rau hauv qhov chaw tseem ceeb. Rau cov ntaub ntawv spindle runout, lawv qhia peb tias yuav siv hom toolholders twg zoo tshaj plaws thiab kev xaiv kev kho kom raug. Qhov no muab kev pab loj rau cov bracket tsim hluv aerospace uas muaj kev sib txawv tuaj yeem ua rau phab nplaum puag. Ib tug neeg tshawb fik NIST piav tias kev sai hauv phab nplaum dimin 60% thaum muaj kev them nyiaj meej meej. Qhov kev them nyiaj no zoo dua kev nthuav dav xwb, tshuav tshaj rau kev tsim khoom rau kev kho mob uas yuav tsum nyob hauv +/- 5 microns. Cov chaw tsim khoom siv digital twins uas nqa taws data feem xyuas tseem ceeb tuaj yeem hloov kho kev them nyiaj thiab kev kho tiam hauv sijhawm. Qhov no txo cov khoom tsis zoo tsis muaj kev hloov tso tseg, tso cai kom phab nplaum nyob saum Ra 0.4 microns hauv tag nrho qhov kev tsim khoom ib txhis, tshaj li thaum tsim khoom ntau hnub.