Nyob rau hauv cov txheej txheem ntawm cov ntawv tshuab, ntau cov yob ua lub luag haujlwm tseem ceeb, los ntawm dewatering ntawm cov ntawv ntub dej mus rau qhov chaw ntawm cov ntawv qhuav. Raws li ib qho ntawm cov thev naus laus zis tseem ceeb hauv kev tsim cov ntawv tshuab yob, "crown" - txawm tias qhov sib txawv me ntsis ntawm geometric nws koom nrog - ncaj qha txiav txim siab qhov sib xws thiab kev ruaj ntseg ntawm daim ntawv zoo. Tsab ntawv xov xwm no yuav qhia meej txog cov cuab yeej siv thev naus laus zis ntawm daim ntawv tshuab yob los ntawm cov ntsiab lus ntawm cov ntsiab lus, kev ua haujlwm, kev faib tawm, kev cuam tshuam tseem ceeb hauv kev tsim, thiab kev saib xyuas, nthuav tawm nws cov nqi tseem ceeb hauv kev tsim cov ntawv.

1. Lub ntsiab lus ntawm yas: Lub luag haujlwm tseem ceeb hauv qhov sib txawv me

"Crown" (hais ua lus Askiv li "Crown") tshwj xeeb yog hais txog cov qauv geometric tshwj xeeb ntawm daim ntawv tshuab yob raws cov kev taw qhia axial (ntev ntev). Txoj kab uas hla ntawm qhov nruab nrab ntawm qhov yob lub cev yog me ntsis loj dua qhov kawg ntawm qhov kawg, tsim ib qho contour zoo ib yam li "lub duav nruas". Qhov kab sib txawv no feem ntau yog ntsuas hauv micrometers (μm), thiab tus nqi ntawm cov ntawv xovxwm loj tuaj yeem ncav cuag 0.1-0.5 hli.

Qhov taw qhia tseem ceeb rau kev ntsuas lub crown tsim yog "tus nqi crown", uas yog xam raws li qhov sib txawv ntawm qhov siab tshaj plaws txoj kab uas hla ntawm lub yob lub cev (feem ntau yog nyob rau nruab nrab ntawm lub axial kev taw qhia) thiab txoj kab uas hla ntawm yob xaus. Nyob rau hauv qhov tseeb, lub crown tsim yuav presetting no me me txoj kab uas hla sib txawv los offset lub "middle sag" deformation ntawm yob los ntawm tej yam xws li quab yuam thiab kub hloov thaum lub sij hawm ua hauj lwm. Thaum kawg, nws ua tiav qhov kev faib tawm ntawm kev sib cuag siab thoob plaws tag nrho qhov dav ntawm lub yob nto thiab daim ntawv lub vev xaib (lossis lwm yam sib txuas), tso lub hauv paus ruaj khov rau daim ntawv zoo.

2. Core Functions of Crown: Compensating Deformation and Maintaining Uniform Pressure

Thaum lub sijhawm ua haujlwm ntawm daim ntawv tshuab yob, deformation yog qhov tsis tuaj yeem vim yog cov khoom thauj khoom, kub hloov pauv, thiab lwm yam. Yog tsis muaj cov qauv tsim, qhov deformation yuav ua rau tsis sib xws ntawm kev sib cuag ntawm lub yob nto thiab daim ntawv lub vev xaib - "siab dua ntawm ob qho kawg thiab qis qis hauv nruab nrab" - ncaj qha ua rau muaj teeb meem loj xws li qhov hnyav hnyav thiab tsis sib xws ntawm daim ntawv. Tus nqi tseem ceeb ntawm cov yas yog nyob rau hauv nquag them nyiaj rau cov deformations, uas yog qhia tshwj xeeb hauv cov hauv qab no:

2.1 Compensating rau Yob dabtsi yog khoov deformation

Thaum cov core yob ntawm daim ntawv tshuab, xws li xovxwm yob thiab calender yob, yog nyob rau hauv kev ua haujlwm, lawv yuav tsum tau siv lub zog loj rau daim ntawv lub vev xaib. Piv txwv li, lub siab tawm ntawm cov xovxwm yob tuaj yeem ncav cuag 100-500 kN / m. Rau rolls nrog ib tug loj ntev-rau-ntev piv (piv txwv li, qhov ntev ntawm xovxwm yob nyob rau hauv dav-dav daim ntawv tshuab yuav ua tau 8-12 meters), elastic deformation ntawm downward dabtsi yog khoov nyob rau hauv nruab nrab tshwm sim nyob rau hauv siab, zoo ib yam li "lub xub pwg nyom dabtsi yog khoov nyob rau hauv load". Qhov deformation no ua rau muaj kev sib cuag ntau dhau ntawm cov yob kawg thiab cov ntawv web, thaum lub siab nyob nruab nrab tsis txaus. Yog li ntawd, daim ntawv lub vev xaib dhau los ua dej ntau dhau ntawm ob qho kawg (ua rau muaj qhov qhuav qhuav thiab qhov hnyav qis) thiab qis qis hauv nruab nrab (ua rau qis qhuav thiab qhov hnyav hnyav).

Txawm li cas los xij, "nruas-puab" qauv ntawm cov qauv tsim ua kom ntseeg tau tias tom qab yob khoov, tag nrho cov npoo ntawm cov yob tseem nyob rau tib lub sijhawm sib txuas nrog cov ntawv web, ua tiav cov kev sib faib siab. Qhov no ua tau zoo hais txog qhov tsis zoo uas tshwm sim los ntawm kev khoov deformation.

2.2 Kev them nyiaj rau Roll Thermal Deformation

Qee cov yob, xws li phau ntawv qhia yob thiab calender yob nyob rau hauv seem ziab, raug thermal expansion thaum lub sij hawm ua hauj lwm vim muaj kev sib cuag nrog high-temperature ntawv webs thiab chav cua sov. Txij li thaum nruab nrab ib feem ntawm lub cev yob yog ntau dua rhuab (qhov kawg yog txuas nrog bearings thiab dissipate tshav kub sai), nws thermal expansion yog ntau tshaj qhov kawg, ua rau ib tug "middle bulge" ntawm lub yob lub cev. Nyob rau hauv cov ntaub ntawv no, kev siv cov pa crown tsim yuav exacerbate lub uneven kev sib cuag. Yog li ntawd, ib tug "tsis zoo crown" (qhov twg txoj kab uas hla ntawm qhov nruab nrab ib feem me me tshaj qhov kawg, los yog hu ua "rov qab crown") yuav tsum tau tsim los offset lub ntxiv bulge tshwm sim los ntawm thermal expansion, kom ntseeg tau tias uniform sib cuag siab ntawm yob nto.

2.3 Kev them nyiaj rau qhov tsis sib xws Roll Nto Hnav

Thaum lub sijhawm ua haujlwm ntev, qee qhov yob (xws li xovxwm roj hmab yob) muaj kev sib txhuam ntau zaus ntawm cov npoo ntawm daim ntawv lub vev xaib (raws li cov npoo ntawm daim ntawv lub vev xaib nyiam nqa cov impurities), uas ua rau hnav sai dua ntawm qhov kawg ntawm qhov nruab nrab. Yog tsis muaj tus qauv tsim, lub yob nto yuav qhia tau tias "qhov loj ntawm qhov nruab nrab thiab sag ntawm qhov kawg" tom qab hnav, uas ua rau muaj kev cuam tshuam rau kev faib tawm. Los ntawm presetting lub crown, lub uniformity ntawm yob nto contour yuav tsum tau khaws cia nyob rau hauv thaum ntxov theem ntawm hnav, ncua kev pab cuam lub neej ntawm yob thiab txo zus tau tej cov fluctuations tshwm sim los ntawm hnav.

3. Kev faib tawm ntawm cov yas: Cov kev xaiv kev hloov kho rau kev ua haujlwm sib txawv

Raws li hom ntawv tshuab (tsawg-ceev / high-ceev, nqaim-dav / dav-dav), yob muaj nuj nqi (nias / calendering / guiding), thiab cov txheej txheem yuav tsum tau, crown yuav muab faib ua ntau hom. Kev sib txawv ntawm cov yas sib txawv hauv cov qauv tsim, kev hloov kho, thiab daim ntawv thov scenarios, raws li cov lus piav qhia hauv qab no:

4. Qhov tseem ceeb cuam tshuam rau hauv Crown Design: Kev xam meej meej kom haum rau cov kev xav tau ntau lawm

Tus nqi ntawm lub crown yog tsis teem arbitrarily; nws yuav tsum tau muab xam ua ke raws li yob tsis thiab txheej txheem txheej txheem los xyuas kom meej nws cov hauj lwm zoo. Cov yam tseem ceeb uas cuam tshuam rau kev tsim lub crown feem ntau suav nrog cov hauv qab no:

4.1 Roll Dimensions thiab Khoom siv

1. Roll lub cev Length (L): Lub yob lub cev ntev dua, qhov ntau dua qhov khoov deformation nyob rau hauv tib lub siab, thiab yog li qhov loj dua qhov yuav tsum tau muaj tus nqi. Piv txwv li, cov yob ntev hauv cov tshuab ntawv dav dav yuav tsum muaj tus nqi loj dua li cov yob luv hauv cov tshuab ntawv nqaim kom them nyiaj rau deformation.
2. Roll lub cev Diameter (D): Qhov me me ntawm cov yob lub cev txoj kab uas hla, qhov qis dua qhov rigidity, thiab ntau qhov yob yog deformation nyob rau hauv siab. Yog li ntawd, yuav tsum muaj tus nqi loj dua. Conversely, yob nrog ib tug loj txoj kab uas hla muaj ntau rigidity, thiab lub crown tus nqi yuav raug txo kom tsim nyog.
3. Khoom Rigidity: Cov ntaub ntawv sib txawv ntawm lub cev yob muaj qhov sib txawv rigidities; Piv txwv li, steel rolls muaj rigidity ntau dua li cam khwb cia hlau yob. Cov ntaub ntawv nrog qis rigidity nthuav qhia ntau deformation nyob rau hauv siab, yuav tsum tau ib tug loj crown tus nqi.

4.2 Kev Ua Haujlwm Siab (Linear Siab)

Kev khiav hauj lwm siab (linear siab) ntawm rolls xws li xovxwm yob thiab calender yob yog ib qho tseem ceeb uas cuam tshuam rau lub crown tsim. Qhov siab dua ntawm cov kab hluav taws xob, qhov tseem ceeb dua qhov khoov deformation ntawm lub cev yob, thiab tus nqi ntawm cov yas yuav tsum tau nce ntxiv kom raws li qhov yuav tsum tau ua. Lawv txoj kev sib raug zoo tuaj yeem piav qhia los ntawm cov qauv yooj yim: Crown Tus Nqi H ≈ (P × L³) / (48 × E × I), qhov twg P yog qhov siab, L yog qhov yob ntev, E yog lub elastic modulus ntawm cov khoom, thiab kuv yog lub sijhawm ntawm inertia ntawm yob hla ntu. Piv txwv li, lub siab tawm ntawm cov xovxwm yob rau cov ntawv ntim feem ntau yog siab dua 300 kN / m, yog li tus nqi sib xws yuav tsum loj dua li ntawm cov xovxwm yob rau cov ntawv kab lis kev cai nrog qis linear siab.

4.3 Tshuab ceev thiab hom ntawv

1. Tshuab ceev: Thaum cov tshuab ntawv siab ceev (ceev> 1200 m / min) ua haujlwm, daim ntawv lub vev xaib muaj kev nkag siab ntau dua rau kev sib npaug siab dua li hauv cov tshuab ntawv qis. Txawm tias qhov hloov pauv me me tuaj yeem ua rau cov ntawv tsis zoo. Yog li ntawd, cov tshuab ntawv high-ceev feem ntau txais yuav "tswj yas" kom paub txog lub sijhawm them nyiaj rau kev hloov pauv hloov pauv thiab ua kom ruaj khov.
2. Hom ntawv: Cov ntawv sib txawv muaj cov kev xav tau sib txawv rau kev sib txawv siab. Cov ntaub so ntswg (piv txwv li, daim ntawv tso quav tso quav nrog lub hauv paus hnyav ntawm 10-20 g / m²) muaj qhov hnyav ntawm lub hauv paus thiab tsis tshua muaj siab rau kev hloov pauv, xav tau kev tsim cov yas yas. Hauv qhov sib piv, cov ntawv tuab (xws li, cov duab los qhia nrog lub hauv paus hnyav ntawm 150-400 g / m²) muaj peev xwm tiv taus cov kev hloov pauv siab, yog li qhov yuav tsum tau ua rau cov yas yas tuaj yeem txo qis kom tsim nyog.

5. Cov teeb meem thiab kev tu vaj tse: Kev soj ntsuam raws sij hawm kom ntseeg tau tias ruaj khov

Kev tsim cov yas tsis tsim nyog lossis kev saib xyuas tsis raug yuav cuam tshuam rau daim ntawv zoo thiab ua rau muaj teeb meem ntau lawm. Cov teeb meem uas tshwm sim thiab cov kev tawm tsam sib xws yog raws li hauv qab no:

5.1 Muaj nuj nqis loj heev

Ib qho txiaj ntsig loj heev ua rau muaj kev ntxhov siab ntau dhau ntawm qhov nruab nrab ntawm qhov yob nto, ua rau lub hauv paus qis thiab siab qhuav ntawm daim ntawv hauv nruab nrab. Hauv qhov xwm txheej hnyav, nws tuaj yeem ua rau "sib tsoo" (fiber breakage), cuam tshuam rau lub zog thiab zoo li ntawm daim ntawv.

Kev tiv thaiv: Rau cov yas yob ruaj khov siv hauv cov tshuab ntawv qis, nws yog ib qho tsim nyog los hloov cov yob nrog tus nqi tsim nyog. Rau kev tswj cov yas yob hauv cov tshuab ntawv siab ceev, hydraulic lossis pneumatic siab tuaj yeem raug txo los ntawm kev tswj cov yas yas kom txo tau cov nqi yas kom txog thaum lub siab sib faib.

5.2 Tus nqi me me heev

Tus nqi me me heev dhau los ua rau tsis txaus siab nyob rau hauv nruab nrab ntawm lub yob nto, ua rau tsis txaus dewatering ntawm daim ntawv nyob rau hauv nruab nrab, tsis tshua muaj dryness, siab luj, thiab zoo tsis xws luag xws li "ntub chaw". Nyob rau tib lub sijhawm, nws kuj tseem tuaj yeem cuam tshuam rau kev ua haujlwm ntawm cov txheej txheem ziab tom ntej.

Kev tiv thaiv: Rau cov yas yob ruaj khov, lub yob lub cev yuav tsum tau rov ua dua tshiab kom nce tus nqi yas. Rau kev tswj cov yas rolls, hydraulic los yog pneumatic siab tuaj yeem ua kom nce tus nqi ntawm cov yas, kom ntseeg tau tias lub siab nyob hauv nruab nrab ua tau raws li cov txheej txheem.

5.3 Hnav tsis sib xws ntawm Crown Contour

Tom qab ua haujlwm ntev, qhov yob nto yuav muaj kev hnav. Yog tias qhov hnav tsis sib xws, lub ntsej muag lub ntsej muag yuav raug deformed, thiab "qhov tsis sib xws" yuav tshwm sim ntawm qhov yob. Qhov no ua rau muaj qhov tsis xws luag xws li "stripes" thiab "indentations" ntawm daim ntawv, cuam tshuam rau qhov zoo ntawm daim ntawv.

Kev tiv thaiv: Tsis tu ncua tshuaj xyuas qhov yob nto. Thaum hnav mus txog ib theem, kev sib tsoo thiab kho cov yob nto (piv txwv li, regrind lub yas contour ntawm cov xovxwm roj hmab yob) kom rov zoo li qub thiab qhov loj ntawm cov yas thiab tiv thaiv kev hnav ntau dhau los ntawm kev cuam tshuam ntau lawm.

6. Cov lus xaus

Raws li kev siv thev naus laus zis zoo li tsis yooj yim tab sis tseem ceeb, lub kaus mom ntawm daim ntawv tshuab yob yog lub hauv paus rau kev ua kom cov ntawv zoo ib yam. Los ntawm cov yas ruaj ruaj hauv cov tshuab ntawv qis kom tswj tau cov yas hauv high-ceev, dav-dav cov tshuab ntawv, kev txhim kho txuas ntxiv ntawm cov cuab yeej siv hluav taws xob ib txwm nyob rau ntawm lub hom phiaj tseem ceeb ntawm "paub deformation thiab ua tiav cov siab sib xws", hloov mus rau cov kev xav tau ntawm cov ntawv sib txawv ua haujlwm. Tsim nyog crown tsim tsis tsuas yog daws cov teeb meem zoo xws li cov ntaub ntawv tsis sib xws thiab kev dewatering tsis zoo tab sis kuj tseem txhim kho kev ua haujlwm ntawm cov ntawv tshuab (txo cov ntawv so) thiab txo cov kev siv hluav taws xob (tsis txhob ziab dhau). Nws yog ib qho tseem ceeb tseem ceeb kev txhawb nqa hauv kev tsim cov ntawv kev lag luam rau "zoo, kev ua haujlwm siab, thiab kev siv hluav taws xob tsawg". Nyob rau yav tom ntej daim ntawv ntau lawm, nrog rau kev txhim kho tas mus li ntawm cov cuab yeej precision thiab kev ua kom zoo dua qub ntawm cov txheej txheem, cov tshuab yas yas yuav ua kom zoo dua qub thiab txawj ntse, ua rau muaj txiaj ntsig zoo rau kev tsim cov ntawv zoo.