MAGNABEND - KEV PAB CUAM TSHUAJ TIV THAIV
Basic Magnet Design
Lub tshuab Magnabend yog tsim los ua ib lub zog DC hlau nplaum uas muaj lub luag haujlwm tsawg.
Lub tshuab muaj 3 qhov tseem ceeb: -
Lub cev hlau nplaum uas tsim lub hauv paus ntawm lub tshuab thiab muaj cov electro-magnet coil.
Lub clamp bar uas muab txoj hauv kev rau cov hlau nplaum sib nqus ntawm cov ncej ntawm lub hauv paus hlau nplaum, thiab yog li clamps cov ntawv hlau ua haujlwm.
Lub beam dabtsi yog khoov uas yog pivoted rau pem hauv ntej ntug ntawm lub hlau nplaum lub cev thiab muab ib tug txhais tau tias rau siv dabtsi yog khoov quab yuam rau lub workpiece.
Magnet-Lub cev Configurations
Ntau yam kev teeb tsa ua tau rau lub cev hlau nplaum.
Nov yog 2 uas tau siv rau Magnabend tshuab:
Cov kab liab liab hauv cov duab kos saum toj no sawv cev rau txoj hauv kev sib nqus flux.Nco ntsoov tias "U-Type" tsim muaj ib txoj hauv kev flux (1 khub ntawm tus ncej) whereas "E-Type" tsim muaj 2 txoj hauv kev (2 khub ntawm ncej).
Magnet Configuration Sib piv:
Kev teeb tsa E-hom muaj txiaj ntsig zoo dua li U-hom teeb tsa.
Yuav kom nkag siab yog vim li cas qhov no thiaj li xav txog ob daim duab hauv qab no.
Nyob rau sab laug yog ntu ntu ntawm U-hom hlau nplaum thiab sab xis yog E-hom hlau nplaum uas tau ua los ntawm kev sib txuas 2 ntawm tib hom U.Yog hais tias txhua qhov kev teeb tsa hlau nplaum yog tsav los ntawm ib lub kauj nrog tib lub ampere-tig ces kom meej meej cov hlau nplaum ob npaug (tus E-hom) yuav muaj ob npaug ntau dua clamping quab yuam.Nws kuj tseem siv ob zaug ntau dua steel tab sis tsis tshua muaj hlau ntxiv rau lub kauj!(Piv txwv li tus qauv coil ntev).
(Qhov me me ntawm cov xaim ntxiv tsuas yog xav tau vim tias 2 ob txhais ceg ntawm lub kauj sib txuas ntxiv nyob rau hauv "E" tsim, tab sis qhov ntxiv no ua tsis tseem ceeb hauv kev tsim coil ntev xws li siv rau Magnabend).
Super Magnabend:
Txhawm rau tsim kom muaj cov hlau nplaum muaj zog dua lub tswv yim "E" tuaj yeem txuas ntxiv xws li qhov kev teeb tsa ob-E:
Qauv: 3D
Hauv qab no yog ib daim duab 3-D uas qhia txog qhov kev npaj ntawm qhov chaw hauv U-hom hlau nplaum:
Nyob rau hauv no tsim lub Pem hauv ntej thiab nram qab ncej yog cais daim thiab txuas los ntawm bolts rau lub Core piece.
Txawm hais tias nyob rau hauv txoj cai, nws yuav ua tau rau tshuab U-hom hlau nplaum lub cev los ntawm ib daim hlau, ces nws yuav tsis muaj peev xwm nruab lub kauj thiab yog li lub kauj yuav tsum tau raug mob nyob rau hauv situ (ntawm lub machined hlau nplaum lub cev. ).
Nyob rau hauv ib qho teeb meem ntau lawm nws yog ntshaw kom muaj peev xwm cua lub coils nyias (ntawm ib tug tshwj xeeb qub).Yog li U-hom tsim tau zoo dictates ib qho kev tsim kho.
Ntawm qhov tod tes, E-hom tsim qiv nws tus kheej zoo rau cov hlau nplaum lub cev machined los ntawm ib qho ntawm cov hlau vim tias lub kauj ua ntej tuaj yeem ntsia tau yooj yim tom qab lub cev hlau nplaum tau raug machined.Ib lub cev hlau nplaum ib leeg kuj ua tau zoo dua hlau nplaum vim nws tsis muaj qhov sib txawv ntawm kev tsim kho uas yuav txo tau cov hlau nplaum sib nqus (thiab yog li lub zog clamping) me ntsis.
(Feem ntau Magnabends ua tom qab 1990 ua haujlwm E-hom tsim).
Xaiv cov khoom siv hlau nplaum tsim
Lub cev hlau nplaum thiab lub clampbar yuav tsum tau ua los ntawm cov khoom siv ferromagnetic (magneticisable).Hlau yog nyob deb ntawm cov khoom siv ferromagnetic pheej yig tshaj plaws thiab yog qhov kev xaiv pom tseeb.Txawm li cas los xij muaj ntau yam tshwj xeeb steels muaj uas yuav raug txiav txim siab.
1) Silicon Steel: High resistivity steel uas feem ntau muaj nyob rau hauv nyias laminations thiab yog siv nyob rau hauv AC transformers, AC hlau nplaum, relays thiab lwm yam. Nws cov khoom tsis tas yuav tsum tau rau Magnabend uas yog DC hlau nplaum.
2) Cov Hlau Hlau: Cov khoom siv no yuav pom cov hlau nplaum qis dua uas yuav zoo rau lub tshuab Magnabend tab sis nws yog lub cev mos uas txhais tau tias nws yuav yooj yim dented thiab puas;nws yog qhov zoo dua los daws qhov teeb meem ntawm qhov seem hlau nplaum lwm txoj kev.
3) Cam khwb cia hlau: Tsis yooj yim magnetized li dov hlau tab sis tuaj yeem txiav txim siab.
4) Stainless Steel Hom 416: Tsis tuaj yeem sib nqus tau zoo li hlau thiab kim dua (tab sis tej zaum yuav muaj txiaj ntsig zoo rau lub ntsej muag tiv thaiv lub ntsej muag ntawm lub cev hlau nplaum).
5) Stainless Hlau Hom 316: Qhov no yog cov hlau tsis sib nqus ntawm cov hlau thiab yog li tsis haum txhua (tshwj tsis yog hauv 4 saum toj no).
6) Medium Carbon Steel, hom K1045: Cov khoom no yog eminently haum rau kev tsim cov hlau nplaum, (thiab lwm yam ntawm lub tshuab).Nws yog qhov tsim nyog nyuaj nyob rau hauv cov khoom raws li cov khoom siv thiab nws kuj tshuab tau zoo.
7) Medium Carbon Steel hom CS1020: Cov hlau no tsis nyuaj npaum li K1045 tab sis nws tau yooj yim dua thiab yog li yuav yog qhov kev xaiv zoo tshaj plaws rau kev tsim kho lub tshuab Magnabend.
Nco ntsoov tias cov khoom tseem ceeb uas yuav tsum tau muaj yog:
High saturation magnetization.(Feem ntau steel alloys saturate nyob ib ncig ntawm 2 Tesla),
Muaj nyob ntawm qhov loj me me,
Resistance rau tej yam kev puas tsuaj,
Machinability, thiab
Tus nqi tsim nyog.
Nruab nrab carbon steel haum rau tag nrho cov kev xav tau zoo.Cov pa roj carbon tsawg kuj tseem siv tau tab sis nws tsis tshua muaj kev tiv thaiv kev puas tsuaj.Kuj tseem muaj lwm cov alloys tshwj xeeb, xws li supermendur, uas muaj ntau dua saturation magnetisation tab sis lawv yuav tsum tsis txhob xav txog vim tias lawv cov nqi siab heev piv rau cov hlau.
Cov pa roj carbon nruab nrab txawm li cas los xij muaj qee qhov seem hlau nplaum uas txaus los ua qhov tsis zoo.(Saib ntu ntawm Residual Magnetism).
Lub Coil
Lub kauj yog dab tsi tsav lub magnetising flux los ntawm electromagnet.Nws lub zog magnetising tsuas yog cov khoom ntawm tus naj npawb ntawm lem (N) thiab lub kauj tam sim no (I).Yog li:
N = Number of turns
Kuv = tam sim no nyob rau hauv windings.
Cov tsos ntawm "N" hauv cov qauv saum toj no ua rau muaj kev xav tsis zoo.
Nws yog dav xav tias nce tus naj npawb ntawm cov lem yuav ua rau cov magnetising quab yuam tab sis feem ntau qhov no tsis tshwm sim vim hais tias ntxiv lem kuj txo qhov tam sim no, I.
Xav txog ib lub kauj uas muab nrog DC voltage ruaj khov.Yog hais tias tus naj npawb ntawm lem yog ob npaug, ces qhov kev tiv thaiv ntawm cov windings kuj yuav tsum tau muab ob npaug rau (nyob rau hauv ib tug ntev coil) thiab yog li tam sim no yuav tsum tau halved.Cov nyhuv net yog tsis nce hauv NI.
Dab tsi tiag tiag txiav txim siab NI yog qhov kev tawm tsam ib zaug.Yog li kom nce NI lub thickness ntawm cov hlau yuav tsum tau nce.Tus nqi ntawm kev hloov pauv ntxiv yog tias lawv txo qis tam sim no thiab yog li lub zog dissipation hauv lub kauj.
Tus tsim qauv yuav tsum nco ntsoov tias lub ntsuas hluav taws xob yog qhov tseeb txiav txim siab lub zog magnetizing ntawm lub kauj.Qhov no yog qhov tseem ceeb tshaj plaws parameter ntawm coil tsim.
Cov khoom NI feem ntau hu ua "ampere tig" ntawm lub kauj.
Yuav tsum muaj pes tsawg Ampere tig?
Hlau nthuav tawm qhov saturation magnetisation txog li 2 Tesla thiab qhov no teeb tsa ib qho tseem ceeb txwv ntawm qhov clamping quab yuam ntau npaum li cas tuaj yeem tau txais.
Los ntawm cov duab saum toj no peb pom tias lub zog teb yuav tsum tau txais qhov flux ceev ntawm 2 Tesla yog li 20,000 ampere-tig ib meter.
Tam sim no, rau tus qauv tsim Magnabend, qhov ntev ntawm txoj kab hauv cov hlau yog li 1/5th ntawm ib lub 'meter' thiab yog li ntawd yuav tsum tau (20,000/5) AT los tsim saturation, uas yog hais txog 4,000 AT.
Nws yuav zoo yog tias muaj ntau yam ampere lem dua li qhov no kom saturation magnetisation tuaj yeem tswj tau txawm tias thaum tsis muaj qhov sib nqus (xws li cov khoom tsis yog-ferrous workpieces) tau nkag mus rau hauv magnetic circuit.Txawm li cas los xij ntxiv ampere lem tuaj yeem tau txais ntawm tus nqi ntau hauv lub zog dissipation lossis tus nqi tooj liab, lossis ob qho tib si.Yog li yuav tsum muaj kev sib haum xeeb.
Hom Magnabend tsim muaj lub kauj uas ua rau 3,800 ampere tig.
Nco ntsoov tias daim duab no tsis yog nyob ntawm qhov ntev ntawm lub tshuab.Yog hais tias tib lub magnetic tsim yog siv nyob rau hauv ib tug ntau yam ntawm lub tshuab lengths ces nws dictates tias cov cav tov ntev yuav muaj tsawg lem ntawm thicker hlau.Lawv yuav kos ntau dua tam sim no tab sis yuav muaj tib yam khoom ntawm amps x lem thiab yuav muaj tib lub zog clamping (thiab tib lub zog dissipation) ib chav tsev ntawm qhov ntev.
Lub luag haujlwm voj voog
Lub tswv yim ntawm lub luag haujlwm lub voj voog yog ib qho tseem ceeb heev ntawm kev tsim cov tshuab electromagnet.Yog tias tus qauv tsim muab ntau lub luag haujlwm lub voj voog ntau dua li qhov xav tau ces nws tsis zoo.Ntau lub voj voog ua haujlwm hauv lub cev txhais tau hais tias yuav xav tau ntau lub xov tooj tooj liab (nrog rau tus nqi siab dua) thiab / lossis yuav muaj lub zog clamping tsawg dua.
Nco tseg: Lub voj voog ua haujlwm siab dua yuav muaj lub zog tsawg dua uas txhais tau tias nws yuav siv lub zog tsawg dua thiab yog li pheej yig dua los ua haujlwm.Txawm li cas los xij, vim tias cov hlau nplaum yog ON rau lub sijhawm luv luv xwb ces tus nqi zog ntawm kev ua haujlwm feem ntau suav tias yog qhov tseem ceeb tsawg.Yog li txoj kev tsim qauv yog kom muaj lub zog ntau npaum li qhov koj tuaj yeem tawm mus nrog rau kev tsis txhob overheating lub windings ntawm lub kauj.(Qhov kev qhia no feem ntau yog tsim los ntawm electromagnet).
Lub Magnabend yog tsim los rau lub voj voog nominal ntawm kwv yees li 25%.
Feem ntau nws tsuas siv 2 lossis 3 vib nas this los ua kom khoov.Cov hlau nplaum yuav tawm mus ntxiv rau 8 mus rau 10 vib nas this thaum lub workpiece repositioned thiab ua raws li npaj rau qhov khoov tom ntej.Yog tias 25% lub voj voog ua haujlwm tau dhau lawm ces thaum kawg cov hlau nplaum yuav kub dhau thiab thermal overload yuav mus.Cov hlau nplaum yuav tsis puas tab sis nws yuav tsum tau tso cai kom txias li 30 feeb ua ntej siv dua.
Kev ua haujlwm nrog cov tshuab hauv thaj chaw tau pom tias 25% lub luag haujlwm lub voj voog yog qhov tsim nyog rau cov neeg siv khoom.Qhov tseeb qee cov neeg siv tau thov kev xaiv lub zog siab ntawm lub tshuab uas muaj ntau lub zog clamping ntawm tus nqi qis dua lub voj voog.
Coil Hla-Sectional Cheeb Tsam
Qhov chaw hla qhov chaw muaj rau lub kauj yuav txiav txim siab qhov siab tshaj plaws ntawm cov hlau tooj liab uas tuaj yeem haum rau hauv. Qhov chaw muaj yuav tsum tsis txhob ntau tshaj qhov xav tau, ua raws li qhov xav tau ntawm ampere tig thiab lub zog dissipation.Muab ntau qhov chaw rau lub kauj yuav ua rau kom qhov loj ntawm cov hlau nplaum thiab ua rau txoj kab ntev ntawm cov hlau (uas yuav txo tau tag nrho cov flux).
Qhov kev sib cav tib yam txhais tau hais tias txawm qhov chaw coil yog muab rau hauv tus qauv tsim nws yuav tsum muaj tag nrho nrog tooj liab hlau.Yog tias nws tsis puv, nws txhais tau hais tias cov hlau nplaum geometry tuaj yeem ua tau zoo dua.
Magnabend Clamping Force:
Daim duab hauv qab no tau txais los ntawm kev sim ntsuas, tab sis nws pom zoo zoo nrog kev suav theoretical.
Lub zog clamping tuaj yeem ua lej los ntawm cov qauv no:
F = quab yuam hauv Newtons
B = magnetic flux density in Teslas
A = thaj tsam ntawm tus ncej hauv m2
µ0 = magnetic permeability tas li, (4π x 10-7)
Piv txwv li peb yuav xam cov clamping quab yuam rau ib tug flux ceev ntawm 2 Tesla:
Yog li F = ½ (2)2 A/µ0
Rau lub zog ntawm chav tsev (siab) peb tuaj yeem tso tus "A" hauv cov qauv.
Yog li siab = 2/µ0 = 2/(4π x 10-7) N/m2.
Qhov no tawm mus rau 1,590,000 N / m2.
Txhawm rau hloov qhov no rau kilograms quab yuam nws tuaj yeem muab faib los ntawm g (9.81).
Yog li: Siab = 162,080 kg / m2 = 16.2 kg / cm2.
Qhov no pom zoo zoo nrog rau qhov ntsuas quab yuam rau xoom qhov sib txawv uas pom nyob rau hauv daim duab saum toj no.
Daim duab no tuaj yeem hloov pauv tau yooj yim rau tag nrho lub zog clamping rau lub tshuab muab los ntawm kev muab faib los ntawm tus ncej ntawm lub tshuab.Rau tus qauv 1250E lub ncej cheeb tsam yog 125 (1.4 + 3.0 + 1.5) = 735 cm2.
Yog li tag nrho, xoom-gap, quab yuam yuav yog (735 x 16.2) = 11,900 kg lossis 11.9 tonnes;txog 9.5 tonnes ib 'meter' ntawm hlau nplaum ntev.
Flux density thiab Clamping siab yog ncaj qha ntsig txog thiab tau pom cov duab hauv qab no:
Tswv yim Clamping Force:
Nyob rau hauv kev xyaum no siab clamping quab yuam tsuas yog puas tau pom thaum nws tsis xav tau (!), uas yog thaum khoov nyias steel workpieces.Thaum khoov tsis-ferrous workpieces lub zog yuav tsawg dua li qhia hauv daim duab saum toj no, thiab (me ntsis xav paub), nws tseem tsawg dua thaum khoov tuab steel workpieces.Qhov no yog vim hais tias lub clamping quab yuam uas yuav tsum tau ua kom ib tug ntse khoov yog ntau dua li qhov xav tau rau lub vojvoog khoov.Yog li dab tsi tshwm sim yog tias thaum khoov mus rau pem hauv ntej ntug ntawm lub clampbar nqa me ntsis yog li cia lub workpiece tsim ib lub vojvoog.
Qhov me me-qhov sib txawv uas yog tsim ua rau me ntsis poob ntawm lub zog clamping tab sis lub zog xav tau los tsim lub vojvoog khoov tau poob ntau dua li muaj cov hlau nplaum clamping quab yuam.Yog li qhov xwm txheej ruaj khov tshwm sim thiab lub clampbar tsis tso tseg.
Dab tsi tau piav qhia saum toj no yog hom kev khoov thaum lub tshuab nyob ze nws cov thickness txwv.Yog hais tias ib tug txawm thicker workpiece yog sim ces, ntawm chav kawm, lub clampbar yuav tshem tawm.
Daim duab no qhia tias yog lub qhov ntswg ntug ntawm lub clampbar tau tawg me ntsis, tsis yog qhov ntse, ces qhov sib txawv ntawm huab cua rau tuab dabtsi yog khoov yuav raug txo.
Qhov tseeb yog qhov teeb meem no thiab Magnabend ua kom zoo yuav muaj lub clampbar nrog lub voj voog ncig.(Ib lub voj voos kheej kheej kuj tseem muaj tsawg dua rau kev puas tsuaj loj piv nrog cov ntug ntse).
Marginal hom ntawm Khoov Failure:
Yog tias qhov khoov tau sim ntawm lub workpiece tuab heev ces lub tshuab yuav tsis khoov nws vim hais tias lub clampbar yuav tsuas nqa tawm.(Zoo hmoo qhov no tsis tshwm sim hauv txoj kev ua yeeb yam; lub clampbar cia li cia mus ntsiag to).
Txawm li cas los xij, yog tias cov khoom siv khoov tsuas yog me ntsis ntau dua li qhov khoov lub peev xwm ntawm cov hlau nplaum, feem ntau yuav ua li cas yog qhov khoov yuav hais txog 60 degrees thiab tom qab ntawd lub clampbar yuav pib xaub rov qab.Hauv hom kev ua tsis tiav no cov hlau nplaum tsuas tuaj yeem tiv thaiv qhov khoov ntawm qhov tsis ncaj los ntawm kev tsim kev sib txhuam ntawm lub workpiece thiab lub txaj ntawm cov hlau nplaum.
Lub thickness sib txawv ntawm qhov tsis ua hauj lwm vim nqa tawm thiab tsis ua hauj lwm vim zawv zawg feem ntau tsis ntau heev.
Lift-off tsis ua hauj lwm yog vim lub workpiece levering pem hauv ntej ntug ntawm lub clampbar upwards.Lub clamping quab yuam nyob rau pem hauv ntej ntug ntawm lub clampbar yog tsuas yog dab tsi resists qhov no.Clamping ntawm ntug ntug muaj qhov cuam tshuam me me vim nws nyob ze rau qhov chaw clampbar yog pivoted.Qhov tseeb nws tsuas yog ib nrab ntawm tag nrho cov clamping quab yuam uas resists nqa-tawm.
Ntawm qhov tod tes, zawv zawg yog tiv thaiv los ntawm tag nrho cov clamping quab yuam tab sis tsuas yog los ntawm kev sib txhuam yog li qhov tseeb kuj nyob ntawm qhov coefficient ntawm kev sib txhuam ntawm lub workpiece thiab qhov chaw ntawm cov hlau nplaum.
Rau cov hlau huv thiab qhuav, kev sib txhuam coefficient tuaj yeem siab li 0.8 tab sis yog tias lubrication tam sim no ces nws yuav qis li 0.2.Feem ntau nws yuav yog qhov chaw nyob nruab nrab ntawm xws li qhov marginal hom ntawm khoov tsis ua haujlwm feem ntau yog vim zawv zawg, tab sis kev sim ua kom muaj kev sib txhuam ntawm cov hlau nplaum tau pom tias tsis tsim nyog.
Thickness Muaj peev xwm:
Rau E-hom hlau nplaum lub cev 98mm dav thiab 48mm sib sib zog nqus thiab nrog 3,800 ampere-tig coil, tag nrho ntev dabtsi yog khoov muaj peev xwm yog 1.6mm.Qhov tuab no siv rau ob daim ntawv steel thiab aluminium ntawv.Yuav muaj tsawg clamping ntawm daim ntawv txhuas tab sis nws yuav tsum tau tsawg dua torque los khoov nws yog li qhov no them nyiaj rau hauv txoj hauv kev kom muab lub peev xwm zoo sib xws rau ob hom hlau.
Yuav tsum muaj qee qhov lus ceeb toom ntawm lub peev xwm khoov tau hais tseg: Qhov tseem ceeb yog tias lub zog tawm los ntawm cov ntawv hlau tuaj yeem sib txawv.Lub peev xwm 1.6 hli siv rau cov hlau uas muaj kev ntxhov siab txog li 250 MPa thiab rau txhuas nrog rau kev ntxhov siab txog li 140 MPa.
Lub thickness muaj peev xwm nyob rau hauv stainless hlau yog hais txog 1.0mm.Lub peev xwm no tsawg dua li lwm cov hlau vim tias cov hlau tsis muaj hlau feem ntau tsis yog hlau nplaum thiab tseem muaj qhov ua rau muaj kev ntxhov siab ntau.
Lwm qhov tseem ceeb yog qhov kub ntawm cov hlau nplaum.Yog hais tias cov hlau nplaum tau raug tso cai los ua kub ces qhov kev tiv thaiv ntawm lub kauj yuav siab dua thiab qhov no nyob rau hauv lem yuav ua rau nws kos tsis tshua muaj tam sim no nrog rau qhov txo qis ampere-tig thiab qis clamping quab yuam.(Cov nyhuv no feem ntau yog nruab nrab thiab tsis zoo li yuav ua rau lub tshuab ua tsis tau raws li nws cov specifications).
Thaum kawg, lub peev xwm thicker Magnabends tuaj yeem ua tau yog tias cov hlau nplaum hla ntu tau ua kom loj dua.