Note: Descriptions are shown in the official language in which they were submitted.
CA 022607~8 1999-01-18
ROTARY WHEEL CASTING M~(:~INE . ' ' ~, .. . ', .~ ..
The invention relates to the continuous casting of steel and other metals and, more particularly, to
an improved rotary wheel-type casting machine for continuous casting of billets, blooms, slabs, bars, rods
and the like.
In the prior art of vertical continuous casting wheels, peripheral closure of the casting mold
channel generally is accomplished by either a moving, endless metal belt pressed against the wheel rim by
rollers to realize closure and synchronous peripheral motion with the ~vheel, or by multiple closure
sel~m~ntC~ or cl~m.chPil-style molds, spaced in abutting sectors around the entire wheel circumference and
rotating with it, which are closed pro~imate the point of pouring steam entry, and reopened at bar e~;it from
10 the casting sector during each revolution of the wheel. Known technology also includes a stationary
closure belt, pressed in frictional contact against the wheel periphery spanning the casting arc.
Disadvantages of the endless belt include: heat from the casting warps the belt, also imparting a
wrinkled and warped surface to the cast stock on the belt side of the section; return rollers are bulky and
occupv useful space: a closed and sealed collector and conduit for spent belt-cooling water is difficult. if
15 not impossible, to realize; belts require a regular schedule of repl~cPmPnt through wear and warpage; belts
do not m~int~in uniform contact and pressure to hold the casting firmly against the wheel as the casting
proceeds around the wheel; and ma~imum width of cast stock is very limited due to belt fle~ure and
warpage. Despite these disadvantages, most commercial production mar.hinPs employ a moving endless
fle~ible metal belt to effect mold closure.
Disadvantages of segmPnt~d molds include mP~h~nir~l complexity with inherently very large
number of cooperating parts and components; diffficulty in ~ sg necessary close tolerances between
large number of interacting wheel sectors usually 2~ or 36, each sector including a clam-shell mold pair.
hl'et-ou.l~;. w~.er pipirig, ml ~h,-i1iç, 1 l~ng~,8 and ac~ iOI1; pru'ulcrlls ~viuh m~tai ~nd ~ia~ spiashes
interfering with mold closure and mold-mold interfaces; and ad-liti- n~l tundish pouring clearance necessary
25 to accommo-l~te individual mold sector height above metal m~ni~cl~5~
Disadvantages of the static closure are inridPnre of sticking between the moving surface of the
initially solidified stock and the stationaIy surface of the closure, resulting in possible skin ruptures and the
like; also wear and operating problems asso~,iat~d with contact friction between wheel perimeter surface
and the closure surface.
Casting wheels having an osçill~ting closure have also been proposed, for example, as described
by patent publication JP-A-58205660, 30 November, 1983, in which a guide mold is osrill~ted in contrast
with the casting wheel, but lacking provision for m~int~ining a constant controlled clearance with the wheel
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CA 022607~8 1999-01-18
rim. High inertia is another common characteristic of prior art devices, maKing rapid oscillatiori difficult. ~ -
A low-inertia closure assembly allowing rapid ~ srill~tion~ in combination with close clearance control, is
lacking in the prior art. Further, the prior art lacks means for precise positioning of c~-nt~inm~nt rollers
relative to the wheel rim, along with control of the c.J"t~;"",~.nt roller pressure against the cast section
5 below the mold, together with capture and disposal of spent coolant, as an integral part of the wheel
assembly, rather than of a bulky e~cternal structure without coolant capture. ~)ractic31 means for ~h~nginsJ
the width of cast slab sections, without ~ ngin~ molds, is also not evident in the prior art of rotary wheel
casters.
It is a principal object of this invention to provide a rotary wheel continuous casting machine
10 which does not have the disadvantages cited above for prior art casting wheels.
Another object is to provide a casting machine which realizes a much higher output per strand of
equivalent cross-section than do conventional vertical, curved or horizontal casting m~ ini s, and thereby
can involve less cost and comple~city for equivalent output.
A further object is to provide, in various embo~im~nt~7 a casting machine capable of casting billet
15 and bloom type sections for rolling into rod, bar and tubing sections and, in a modified embodiment, flat
slab sections suitable for subsequent rolling into plate, sheet and strip products, with the invention
particularly suitable for casting near net shape products such as thin slabs and beam blanks. Varying the
width of slab section without c~nging the wheel channel is a related object.
.
An ~ ition~l object is to provide a casting machine in which the principal force and pressure
20 propelling the cast section forward is inherently effected at the location of the cross section being cast
rather than by the pulling force and tension created by the withdrawal pinch rollers following e~it from the
casting mold and cont~inm~-nt spray chamber area, thus ~limin~ting the main source of skin stresses and
tears, with associated substantial increase in casting rate.
A still further object is to provide a casting machine capable of casting product with very good
2j surface and intemal metallurgical quality.
The invention Cu~ iSeS basic features in c~mmon with the prior art, namely a rotary wheel
continuous casting machine c~ ing a rotary wheel incorporating a ~,h~ ial inner-radius mold
wall with two parallel annular inner mold-wall edges, integral to the wheel rim; a non-rotating casting-
mold sector comprising at least one rigid mold segm~nt~ illco~ol~ g an outer-radius mold wall having
30 two outer mold-wall edges which are parallel to, and interface with, said inner mold-wall
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edges~ formmg a c~sling mold envelope~ between said iMerff~nd outer-radius*~mold wDlls;
molten metal pouring means adapted for inlrodueing molten met~ proxi ate Lhe entry end*~of sDid
mold envelope*~ to pDSS lhrouEII in lhe c~sting direcLion of eirculDr wllcel rotatjon and Dt Ie~st
pDrtially solidify a cast mct~ seclion for exit from the exit end ( 70~ of sDid mold envelopc *~; eYtcmnl
S support mearLs of s~id segment*4t adDpted lo maintain it in a substantinlly fixed nngular posilion in
relation to said wheel; ~oe I ocal oscillation means eonn~cd lo said segment (10) adDpled to effecl
relative annular oscill ~ti~n movement of sDid outer radius mold wDll*~lternDLely in sDid casling and
reverse direetions in relation to sDid support means Dnd thereby between said ouler-rndius mold wall ( l 2)
and said solidifying east section lhe invenlion comprising eombinnlion of lhcsc with nl IeDsl one
10 annular outer-rDdius mold-wnll cdge guide Lrnck~*Lntegrnl to said rolary whcel proxima~e the wheel
rim nnd which is p~rnllel lo sDid pnr~llel mold-wall cdges*;~* ~nd Dt Ienst one guide trDck follower
( I S) fixed to s~id non-rotDling segmcn~ ( 10) which is m,~in~:lin~i in con~act wilh said guidc tr~ck (5 G)
durin~ rotation of said whecl adDplcd lo m,~int,~in a subs~nti~llv const~ll dimcnsional clearance belwcen
said irmer-rndius*tnnd ouLcr-rndius ( I ) mold-wall cdges
A preferred embodimcnl includcs two of s~id guide trncks (5 G) one locaLed on eiuher side of lhe
central plane of rotalion of snid inncr-radius mold wall*~ and at Ieas~ ~wo of said followcrs ( 15) for
eDch of said g ude lracks (5 6)j Dnd said followcrs comprise cam rollcr rollowcrs ( l 5) which run in con~ac~
with sDid trDck~and incorpor~le me~ns of resLrDining relDlive movemenl in the a~iDI ns well ns rndinl
dircclion of said cDrn roller followers~relntive to snid trnck and thcreby be~ween snid inncr (~
20 outer ( 12) mold-wnll edges during whoel rot~lion.
The r3dially guiding surfaces of eDch said guide track (5 6) typically face rDdially oulw~d5 from
the rolation a~is of said wheel ~nd said c~m follower rollers~ride on lhcsc surfaccs and thereby do
nol restrain said casling-mold segrnents ( 10) from movemenl in Lhe rDdiDlly outwDrd direclion In one
embodirnent the wheel cDrries Dnother Dnnular bnl~ncine guide track ( 5) with fDces direc~ed rDdinlly
25 inwards compl~ ..L~y to each outw~rd-facing tr~ck (5 6) ~gDinst which rides at ICDst onc bDlancing
cam follower (~7) attached lo said non-rotating cDsLing-mold sc~mcnt~ul~crcby m~innlining cont~c
bctween said guide track followers~and said guidc trDck (5 6) by rDdially rcstraining movcmcnt of
said casting mold segment*~in Ihe direction radially oulwards from said whccl In anoLhcr
~m~o~i nPn~ c casling mold sc~cr ~ ; Jj also cDrry a suppleme-l~y guidc ;rack*~ agDins; -~ i ch
30 fluid-pressure loDded b~l~nring cam followers~l*maint~in contlnuo ~ prcssurc ~nd contact of lhc
guidc trDck followers*~Dgainst thc wheel rim with the b~l~n~ine followcrs ( I 14) in turn bcing
au~pOI 1~ and po ;l i~.. r~ from D îîxed support of thc machinc housing or the like 1 hc supplcmcntary
track prefcrably includes D reversc cDpturing IlDnge~l 16) for thc b ~l~nrin~ followcr cnabling lhc casting
AMENDED S~E~
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WO 98/0328G - ~ rCTJSA96100473. .
... . ..
. ~.' ' 1 . ~ .
seV"f ~1~ to be lifted off Lhe whecl and held in Sncprncion during inspcction or mnin~rnnn~r
Mold s~g, ls*~most suitably C~ CS a rigid7 semicircular enclosure hDving two box sidc
WDJIs (13), a box outcrcoverw311(143) nnd a box inner wnll c~ ing s3id outcr-rndju5 mold wDll*~on
its face, in which said cxternal support mcans and s3id oscillation means ~fC at~3chcd to Lhc segmenl*43
5 ~hereby being adapLed to oscillaLc said outer-rDdius mold wall ( I ) back and for~h in LI1C circumferenLiat
direction nbout a s~bst~nti ~lly fiYed nngul~r locntion on the c~sLing whcel periphery Sprny noz-,Jes t3X)
arc suitably eon1~in~ wiLhin s~id enclosure dircctcd radi311y inwDrds, to sprny cool3nl dircclly ngninst
said outer-radius mold walls*~3rld spent coolnnt is confined wiLhin Lhc cnclosurc nnd dischargcd Yia an
appropriate outlet duct (10) AlLernatively, Lhc enclosurc may form a pressurized water jncket7 inLcrnnlly
10 b~led to provide ~n annulus for flow of pressurized coolant against Lhc ouLside of mold-wall ( I
Appropriately, Lherc are four studdcd cam roller trtck follo-vers ( 15), wiLh lwo mounLed lo project
outwardJy from e3ch box sidc wnll ( 13) of segment ( 1 0)j ~nd lwo bnl~ncillg c3m rollcr assemblies, one
mounted on thc ouLside of e3ch side w~ll ( 13) of segrnent ( I 0)-intermedi~tc bchveen s3id trDck followers
~ inrlllfiing means for applying a continuous con,~rollcd prcssure Or Lhc bnl3ncing rollcrs ('7) ngninst
15 the trncks~ Sllffirirnt to mmnt~nill thc guide tr~ck followcrs ( I S) in contim10l~C conL ct ~ iLh the
outward-facing guide trackc (5,6)
AnoLher asput of thc invention provides n con~inmrnt-rollcr selctor ('8) adjoining thc mold
envelopc exit end~, similar to Lhe casting mold sector ( I I ) but carrying transversc cont~inmrnt id,cr
rollers4~journalled in bearings (7 ~) supponcd by thc segrncnt sidc waJls ( 13), with faces posi~ioned
20 ~nd adapted to press radially inwards against the outcr face of Llte sccLion bcing cnst LO mnintain Lhe inncr
face of Lhe section pressed against the inner-radius mold wall*~ the ~ngrnti~ll componcnt of Lhis
pressurc nchng to exert a circumferentinl forward propclling forcc on Lhc secLion in the casting direcLion
Menns 3rc providcd for conLrolling t~lc radi31 movcmcnL and prcssurc of Lhesc rollers (fi9) n~ninst ~hc fnv
of thc scction bcing cast
Other acpcct~s of the invention include appar3tus for positionin~ of mov3ble side-darn bars (44)
~ptcd for varying the widLh of tlte meLtl scction being c~st, a t~ngrn~i ~I de"~ ~u. ;**of thc ouLer
mold-wall at the entry end*;~of Llte mold ~ .,lo~ to provide il"~,o~el 3cccss for introducing liquid
me~l; a mold ~!f _ - glid;ng ~ ~U~ t ,."p,,! eable ~o spray coolcd sc!id~ ' coppe. c"sting wh~!
mold rings *3~, Dnd a universal hinge coupling assembly*~conn~~ing Dfljf~ining sc~nrnt~ ( 10, 90)
which aJlows c3ch individu31 to tr3ck indcpcndcn~ly on thc whccl rim, without coupling b3cklash
Various other objects, fe3tures and adv3nt~gcs of the proccss Dnd DppDrD~uS of this invcn~ion will
4-
AME~lD~D SHEET
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W O 98~3286 PCTICA96100473
LeCOmel~r ~ ~ from the following detailed d~:r ant claims, and by ~ef~. e to theP , ,~g Ih~.u~g~, m which:
Fig. I is an illu t-_ ~v side view of a rotary wheel casting mschine . nL " ~nt sccording to the
u~ lio4 i" ~ 'E a wheel sector itl~t~ dt~t in section, along the plane of rotation intc. ~ the mold
5 center line;
Fig. 2 is a section view along plane 2-2 of Fig. I i~.vv~Jv~dti~g a mold cavity of general shape suitable for
the casting of blooms, billels, bars and rods l~ pl;~ to ~ t~livn of long 1,.- 'Fig. 3 is a section view along plane 3-3 of Fig. I;
Fig. 4 is a side vi-~v of the apparatus illustrated in Fig. 3; snd
10 Fig S is a ~-----r ~ ~ sv~ctiOn vicw to that illustratet in Fig. 2 ~ ~ ~ a mold cavity of generat
shspe suitable for casting slsbs, plates, sheets and strip, ss 1")'~ ~ ' - to the ~,~ ' of flat-rolled
p.~tu~,b,
Fig. 6 is a psrtial front el., . a~ view of a - ' d .. ;d~h ~ f ' adapted for casting various
nst-rolled product widths without ~' . e the wheel mold;
Fig. 7 is a s~-in~ ' view along plane 7-7 of Fig. 6;
Fig. 8 is an ill~t~ c partial sectional view of sn 5'~ e ab s ~' ' ~ ~- '- ~ ~ g î ~ idk r
rollers in place of the outer mold wall in the lower portion of the non-rotsting casting sector;
Fig. 9 is a partial top view along plane 9-9 of Fig. 8
Figs. 10, and I 1 illustrate two vanations for c - ~ idlcr roller bearing support, p< ~ , and
pressure a~
Fig. 12 is a cw~ g section view of that illustrated in Figs. 2 and 5, incorporating a mold cavity
adapted for the near net shape casting of ~t~ ...,Iu. ' sections and the like;
Fig. 13 is a split cross ~ ~ .ll~t. _ of a c ~ roller segrnent - ' - ' t;
Fig. 14 is a partial side view of the roller segment of Fig. 13;
25 Fig. 15 is a side cl~ - vicw of an entry mold segment ass~l.bly;
Fig. 16isssectionvicwslongplane 16-160fFig. 15;
Fig. 17A is a section view along plane 17A of Fig. 15;
Fig. 1 7B is a section view along plane 1 7B of Fig. 15;
Fig. 18 is a section vicw slong plsne 18-18 of Fig. 16;
30 Fig. 19 is a side ek,~ generat 5 _ ~' view of an cn t s ' ~' 1~- e mold and roller
segment bslancing dc~ices ;,ul",u~t directly from the fixed machine frame;
Figs. 20, 21 arld 22 illustrate detaits of the e~.- atly supported balancing hC '~ as shown in Fig.
19;
~ Fig. 23 is a section view of a suitabte segment s
35 Fig. 24 is a section view along plane 24-24 of Fig. 23;
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W O 98/03286 PCT/CA96/00473
Fig. 25 is a side el~ view of a ~ ~ roller segment n~ " ~.nt;
Fig. 26 is a section view along plane 26-26 of Fig. 25;
Fig. 27 is a seetion view along plane 27-27 of Fig. 25;
Fig. 28 is a section view along plane 28-28 of Fig. 25; and
Fig. 29 is a seetion view along plane 29-29 of Fig. 27.
Referrin8 to the <1~.. ,, wheel hub f ~ 'y 1, is j- "~ ' upon bearings ' on fixed
supports and the rot~lted by an 1~ r ul) ~ electro - ' ' or bydraulic drive unit, p.cf~_' ~ at
variable and controlled speed. In the embodiment iUu~b tt d, the rotary wheel structure c~ a
~ - ' ' ' - body 2 with radial stiffener ribs 19 s, e between hub I and Ushspcd wheel rim 24, also
10 defining cooling waterJadcet annulus 4. A typical wheel size would be 2-4 meters in ~' , although a
wide range of sizes are possible. It is to be ,, . ~ ' that a b~ ' part of the ~.. ,~s ~re
diagrarnmatic only, par~cularly I~g~.g aspeets known in the art. Wheel mold cooling water is
introdueed, and spent wat.,r dia~,h~ d, via ..~,.y,. A rotary union ~ i into hub
r ~Iy I, supplied to and retun~d from whoel rim 24 via a~ r uj)~ ' ~I wheel mounted water pipes 35.
I S The detsils of this aspect .,nd ..~s other features of the whoel casting machine are not shown or
d~,. .I,cd herein, being well known in the art, and wiLh many known and obvious options as to selection
and CO~b~ available.
Casting whoel rirn 24 carries annular inner radius ~1 d .. ~ " support rings 3 and also two outer-
radius - ' ~ 1 edge g~ute tracks S, 6 r,~ .ng .,~ ' radial surfaoes, di~cted radially outw_rt,
20 one on either side of axial central plane of rotation 7 of the inn~ radius molt w. ll, in the c ~-
jll ~ ' Theinnerr.dius ~ 8mayalsoulcludesidefaccsl8 C " g radiallyo.~l.. ' as
in the ~ ~, ~ ' illustrated for casting of a square cross section, ~ r u~latCIy at right angles to the
inside faee of mold wall 8. The mold wall usually of copper or copper alloy, is fastened to support rings 3
such as by saews spaced around the wheel rim pe. "~ y. On most casting wheels, side faces 18 are
25 tapered to div~ge h ~ lyO.Jh. '~, for - . ~t, at a slope of I or 2 por cent, thcreby r ssuring
' - for I ~ - ' t;s~,h~ b., of the c. st metal se.,tion at exit 20, without edge friction or binding
between the section and side faces 18.
N., r_ C casting mold soctor 11 i.~,u. outer radius DIC~.. " 12 as its inner face
thcrcby forming a casting ~Id c..~clo~ 43 bctwecn said ir~r 8 and outcr 12 mold walls Sector 11
30 yc~- u 1~ asinglcrigidc..~ ~f~ moldsegmentorbemateupinmultiplemoldsegments 10.
In thc ~ ' ~ ' 1 ill~h - ~, sector 11 c ~ es thrcc rigit r ~ '- mold ~ l 0 having thc
abutting cnds of scgmcnt sidc walls 13 ~nt~kavcd and co ~ i togcther by hinge pin~A 14. E~
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scgmcnt 10, in tLLrn, has four cam track followers 15 mouDtcd on sidc walls 13 as two oppositc pairs,
~ ~ - ' to run in contact with guide tracks 5,6. A~ u~ y, thc rollcr rnounting studs u~a
c~ L ' 1" 16, to cnable casy ~ ~ I ' of thc clwance 17 bctwe~en thc ~ r ' g inncr 9, and
outer 21, paralld annular -'' .. 'I edgcs. At, of thcsc k - . in thc ' - '
5 jl' i may bc cffectcd manually using an Allcn wrench applied to a ~ 1~5 ~' sockct in thc stud cnd
of cam roller 15, whilst ~ g the clearanccs with feclcr gauges. ~! ' - down to the 25 micron
area can bc ~ C~rd without any contact across the intcrface, thus r ' e a - mold wall
whilst avoiding wear and galling of these mating surfaccs. At typical casting t~".~ s a~ ~ ~ J~ing
the liquidus, the r b; ~ ' p7 ~ _ of surface tension, viscosity and transient s~ in the
10 prescnce of cold, high~u.,li~,ly mold wall material, gencrally then preclude cntry of metal betwecn the
mc'~ c~g~ faccs proximatc the ,....,.;c...~ The rollcrs 15 arc also provided with flangcs 22 to ridc against
~u~ -'iL ~ guide surfac~es 23, u~u~lJu~ into guude tracks 5,6 to maintain
~ _~ (side-to-side) outer ~ r~i~mPn~ s~ y ~ - brackets, or thc
like, of course may be cmployed to z ug t, or as r~ ~ to, the ~ 16 for
~j oftrackfollowerpositionandthereby :1 17. Outler-radiusmoldwall 12maybe
~ ly ~ ~, for . "' e, rocessed betv"een thc edges to provide a rounded billet corncr and
eliminate thc sharp right-angled comcr at 17 ' iaL~, of a flat platc shcc, a sourcc of possible rolling
mill difficulty.
In order to holt each molt scgment 10 in place u~d assune - contact of cam rollcrs 15
20 with g ude tracks 5, 6 dwing the course of rotation and ap~ llc of prcssurc from the scction bcing
cast, the inncr IIJ ~.all support rings 3 also includc a second set of annular b-' C guidc tracks 25
dirccted ratially inwards, against which ride b~l g cam followers 27~ ln the . L- ' I illustrated,
thcre is one sct c~ p~ .g twû of these rollas 27 applied to cach hinged mold segment 10, each set
-g thc co .~ r ~' g two sets of rollers 15, leveraget to apply ~, r ~ ' ' Iy cqual force to
25 each sct. Thc rollcrs 27 are mountet on ' -' L slide arm 29, guitet for . in the ratial
direction only within supp~t ring sidc brackct 30, ant stroked by b-'- g cylinter 31. Such t-' B
actuators can bc powcrcd by any al"" ùl ~ fluit, but co...~ gases such as air have a clcar
atvantage when in a prcssurc~trol modc of this app~ , by _ . C for whecl and traclc
;r;~y and .---; it~ c without usc of s ,,' ~ p-u~ ~ or scrvo control
30 valvcs or thc likc to meter fluids back ant forth. O5ci"a ' of segrnent 10 along the path definet by cam
rollers 15 along tracks S,6 is cffected, such as by h~ ' ' osc~ 32 acting bctwecn ~~ ' '- brackct
33 fixod to scgrncnt 10 and CA~IIY fixcd suppon brackct 34. A widc r~ngc of forms of hydraulic and
electro ~ ' osc~ rs as well as casting control systerns, arc known in the art of c
casting
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The inner mold walls are 1" ~ foree water-cooled with water suppliet and returned via
at least one set of ~ water pipes 35. Esch segment 10 is supplied with eoolant, usually
water, via an inlet through box side walls 13 or outer co~er wall 143 into enclosed header pipe 37 feeding
coolant spray nozzles 38 which direct the coolant spray 39 to impinge on the exterior surface of outer
5 rstius 'c~ . " 12. Spent coolant flows by gravity through outlets 40 into 1~ r U}ll '~' hosing to a sump
or the like, usually for ~~u~ ' Ease of eoolant e..~ , as compared to flexible belt casters, is
also to be noted. RL..W._' 'r eover plates 41 i,~a~ ' into ~ ~ 10 provite access to the sprays
f~ - -e ant the like, as well as rotation _ ~ of cam roller eccentric ~ ' g 16. These
~,~,f~_"y inclute quick-release ~ a ant sealli.
Start-up and ~r are ~ d~ e i in Y~ "y the sa ne mann~ as a COI.. - ' flexible-
bdt - ' ~, molten metal being pouret from tundish 36 into the entry en i 42 of mold ~.. _lq~ 43 and
the cast metal section ~ ilhb~.... from the exit end 20 by means of powerei ~ .. ' rolls 26, details
om~tted as ..~1! ~own.
Fig. S !-- _ an _ ' - " adaptei for casting of thin slab products. Except for the shape
15 and size of the mold c..~_lopc, it will be seen that the basic machine features are ~ y the same as
those for casting billets and blooms, as i" I by Figs. 2 and 3.
Figs. 6 ~nd 7 illustrate a ! , r ~ r ' to facilitate the casting of vsrious slab widths
without major c~l,-;p~ or ~-~hs~ Ratha than c - = of the cast section
between side faees 18 Of the inner radius mold wall 8, the side faces 89 Of partially so~ ifi~i thin slab 61
20 are confinP~ between the two movable mold side-dam bars 44, also r ~ and ' - i on an arc to
a ~ ~ fit betvllocn irmer 8 and outer l2 mold wall faces. Bars 44 are confined l~ _ly between
side r'i" brsckets 47 of movsble carriage 46, snd ~.u.,~.~.c -"y by the I between pin
50, ~s fixed to c~rriage 46 by bracket 48, ~nd mold o;~l- ' ~ " braclcct 49. Carri~ge 46 is carried
on two pairs of ~ ' rollas S3 which run on ~ ~_~ guide track S 1, providmg linear guided
25 ~ ._ only in the transverse direction. Track S 1, in turn, is fasta~ed to track support bracket S2
attached to segment 10, and thereby transmits the c~.c~..&g circumferential oscillation ) ~ ~ of
thc outer rnold wall to mold side~n bars 44. Rollers 53 are preferably mounted on s;; i., bushings
62, providing for easy and accurate adjus~nent of alignment and cl~ with guide track 51. By
providing a close fit between side brackets 47 and bar 44, these bwhings also facilitate procise
30 ~ t~ of the transv~se slope of bars 44.
Carriages 46 are fixed tra.~ _ly by threaded take-up nuts 59 riding on support bracket 60,
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vsriably F ;' ;-~i axially by rota~ion of oppn~ threaded carriage drive scre vs 58, as driven by
ccntrally locsted hydraulic trsverse motor 54. As ill~tl ~, this is a ~ . ' ~ motor ~ on
splined drive shaft 64, as csrried between flange bearulgs 56 of motor support bracket 55, in turn fixed to
the outer wall of box G~lu~ 0. Torque couple-arms 66 act agamst torque pins 63 to prevent motor
body rotation. Shaft 64, Dn turn, is cn ) ~A~' ~1 at either end to drive screws 58 by c~up' n&~ 57. Mûld
s~ bar 44 1~, upr.~tely c~,.,.~,, .ies a ~ - ~ ' tube of copper alloy, blanked off at both ends,
with coolsnt p..,..d~ via llexible hoses c ~ ~ into coolant inlet and outlet s: ~ - 45, one of
which is internslly piped to the bottom ~ uly of ~ ' . bar 44. The faces of bar 44 may slso be
drilled for lubricant ducts and outlets, to provide face h ~ ~i such as by rapeseed oil during
10 u~
During casting, it is well known that the stock cros~ p.u~ shrinks with cooling
snt so~ - during its tescent wilhin the mold, and slso that the outer Isyer of "skin" of the casting
is e~ ly self-sealing once a co-~ surface has been formed around the casting perimeter, unless
stresses are present ~ - ' to create a rupture and ~ ' "break-out" of rnolten metal In
15 w..~. : ~' o~sei~ n~ mold casters, ~ y all of the withdrswal lorce is usually applied
~o!'- ~ in~ tischarge from a roller sprsy cha nber, or ss assisted by a selected few driven rollers within the
sprsy chamber t~ ~ ~ area. The forccs are thus applied at a remoto point from the solidifying
section st mold exit, or a limited number of selected points along the casting Iength, relying on bar slcin
/eu,,"~r~;,iu~ strength between these points to maintain cnsting integrity. Because of the stresses
2û this creates, a n ' "._ly thick frozen skin is y at mold exit, ' -'ly limiting the .
cssting speed, to allow s ~ time for fo. of this skin.
Within the mold e..._lopc, a taper can be added lo the outer-radius mold walls 12 by ~ ~,1 P e
the portion of the fsce of oulcr-radius mold walls 12 within sides 18. In addition, Fig. 8 shows a varistion
g a containment roller wheel sector 28 i.~-~ e - roller .. ,5, - ~ 90 which carTy
2S ~inm~t idler rollers 69, in place of outer r~dius -~ 12, with coolant sprays 39 thereby
directly upon the surface of the csst rnelal section. Along the arc of wheel sector 28, the
forces csn lhcn be applied directly by the rollers 69 at the cross section being cast, by
g ststic L ' contact and pressure between the stock slcin surface and the inner radius mold
walls 8, as they move and propel the casting along at esscntially identical surface speod. Tensional
casting stress is thereby nearly elin~inated, allowing a very substantial increase in praetieal easting speed
for similar effeetive mold lenB~s. Sinee the casting wl~d rotation is funishing the propulsive force, the
powercd withdrawal rollcrs 26 src also usually supcrfluous. For casting wide slab scctions, rollcrs 69
msy also bc split into multiplc lengths .. ~.~.u. e ~ .. ~liate ~ ~, a~ ' g
CA 022607~8 1999-01-18
It is obvious that minor leakage of spent cooling water can take placè via cleararices I~l, in the '-
absence of sealed contact between side walls 13 and inner mold-wall edges 9. A supplementary seal may
be added to minimi~e this leakage (not illustrated) Suitable practice could provide on the order of a meter
of wheel arc, e.g. one box enclosure 10 at the top, as illustrated, incorporating outer mold ~valls 12 ~nd the
two bottom segments 90 be equipped with rollers 69. It will also be obvious that only the top sector l l
need be oscillated, as an option. One or more of the cont~inm~nt rollers 69 may also be applied to effect
thickness re~ ction of the cast metal section by increasing the roller pressure, optionally including liquid
core rerl--ction when the section is only partially solidified. These rollers may be undriven idlers or,
alternatively, powered so as to rotate the roller surface at a ratc s~nchronized with the surface speed of the
10 cast met~l section.
For starting of casting, a starter block or starter bar is usually inserted into the mold cavity,
designed to move in unison with the wheel once casting cnmm~n~ PS. When the block can be confined
between the wheel rim and cont~inm~nt rollers, only a relatively short starter bar is required or,
alternatively, a short starter block head having a longer, flexible elastomer bar att~rhP~, which can be
1~ hollow ~Id col1toured to fit snugl~ .n the ~vheel groove, in order to assist with section guidance following
exit from the machine. The block characteristically includes a protruding top hook or claw designed to
hold the starter block and freshly cast metal together in one piece until they are separated following exit.
One practical diffficulty in the casting of thin slab product is the desired narrow slab thi~kn~5s in
relahon to the dimensions of submerged-entry nozzles. Figs. 8 and 9 illustrate means to mitigate this
20 problem by a funnel-shaped departure on only the outer-radius mold wall at the nozzle 65, wherein wall 12
is e~t~ndPd vertically and t~ng~onti~lly upwards, as at 67, at right angles to the wheel horizontal center line
80 in the plane of rotation of the wheel, at the transverse location of submerged entr nozzle 6~, on either
side of which mold-wall 12 is graduated into the straight-sided cylindrical wall, in the form of a half
funnel-segment 68 with maximum width at the location of molten metal entry 42. In the embodiment
2~ illustrated, where the thickness of nozzle 65 is nearly equal to the casting thickness, it may be seen that
adequate insertion is obtained, in~ ing good wall clearance, by vertical insertion of nozzle 6~ parallel to
this vertical funnel wall.
Fig. 10 illustrates a co"~;l;"",~ " roller positioning and pressure-adjustment assembly 127 for
L~ v~.~e cont~inm~nt rollers 69 against the outer section surface. The roller shafts 71 are journalled
30 within sealed cartridge bearings 72, riding in guided chocks 73, as recessed in the structure of side-walls
13 of segment 90. The chocks 73 and thereby rollers 69 are loaded and retracted by air or hydraulic
cylinders 70, through which the position or force of each roller against the cast metal section surface 104
.. -10-
AMENDED SI~EFr
CA 022607~8 1999-01-18
n n ~ ''
can be adjusted.
Fig. 11 illustrates another embodiment of po~itioning and pressure-adjustment assembly 127 for
rollers 69, whereby the outer race of bearings 72, mollntP,d on roll shaft 83, are carried within an eccentric
bushing 76. Rotating means for bushing 76, such as a pivotally mounted cylinder or rotary actuator (not
5 shown) actl~tinD lever arm 77 of the bushing, can effect both controlled pressure and controlled position
of roller 69. Cooling water can also be supplied via rotary union 78 through internal ducting within shaft
83 to roll water cooling annulus 79. The bearings 72 can also be located outside of wall 13 in other
embodiments. such as by extension of shafts 71~ 83 shown in Fig. 10 or Fig. I l .
Fig. 12 illustrates an embodiment in which the mold envelope is in the form of a near net shape
10 structural beam blank. It ~vill be evident that a variety of such mold shapes and sizes can be applied as
variations on the basic features of the apparatus of the invention.
Figs. 13 and 14 illustrate a cont:~inment roller segment variation, in conjunction with a wheel in
which a spmy-cooled copper block mold ring 93 comprises the wheel rim, combining the fimctions of inrcr
mold wall 8 and annular outer radius mold wall edge guide track 6. Cam roller track followers 15 ride
15 directly on the mold rim, (guide track 5,6) with flanges 22 riding against bevelled edge surface 94 of mold
ring 93. Balancing rollers in this case may more conveniently be mounted to act between the roller
segment and a fixed support attached to the machine base, backing frame or the like, rather than the
rotating wheel. Mold ring 93 is appropriately cooled by means of inside coolant sprays 159 and side
sprays 160. Roll shaft ~4 is fixed, except for rotahon together with eYtPrn:llly eccentric bushmgs 85 keyed
20 or otherwise fixed to shaft 84, and also concentrically supports the inner race of bearing cartridge 72
carrying roller 69 on the outer races. Pneumatic or hydraulic cylinders 91 function similarly to rotarv
actu~tors by stroking eccentnc lever arm 92 to control position and pressure of cnnt~inmPnr rollers 95
against the outer surface iO4 of the soiidifying cast metai section. Thls arr~ngPmPnt ~rilit~tps close
control of the face position of roller 69 in rela*on to surface 1 û4, such as by precise pocitioning of cylinder
25 91, for example, employing posi*on sensors for the rod of a hydraulically operated cylinder, in~ ing a
tr~ncd-lcer to accomplish remote electronic ~lt- m~*c posi*on control, to m~int~in set-point posi*ons. In a
case where roller pressure control only is deemed required, the rollers could be directly and individuallv
supported with reference to the machine base or backing plate only, ~ rollers l j,22 and allowing
radial roller position to follow the vari~tione in position of cas*ng surface lû4 as the wheel rotates,
3û cylinder 91 being operated pnPllm~ti~lly. I~ever a~ns 92 of adjacent rollers may also be linked together
providing for actll~tion of two or more rollers 69 with one cylinder, but with the poten*al
AMENDED SHEET
,, , . . .. . . .. _ _
CA 02260758 1999-01-18
PCT/CA96/00473
WO 98103286
dissdvantage of unequal roller p.~u.es or stock-to-roll~ ~'~ e 1-1 orter to sllow
rvll t L ~ g, in r t with a full ~ t~_ on awsy from the wheel for - ~ and
the like, a three-position duplex cylinter or c~ _' coult vc - , ~ i in place of single cylinder 91.
Figs. lS, 16, 17A ~ 17B and 18 illustrate ld ' ~' or dternative embodiments of the molt
5 segment . ~ _- ~ 10. This includes a ~ ,~u--~ wster-filled inlet chstnber 106 separstet from outht
cbamber 107bydivitingwall 108,-.~. Ebaflleplatc lO9,asheltinpositionbyd~_.. t-' -110,
to ~sure high ~_l~ity water flow within annulus 1 1 1 for cooling of outer radius mold wall sboe 1 12.
Draw-bolts 1 10 sre sealed by wsy of sn c ., vlJ- l 0-ring gland 1 13. The outer ratius mold wsll shoes
11 2 are sealed by an el~ coated metal gasket 1 30 ant fastencd in position by s~ews 1 31 . Among
other features ill~b 1' ~ 1 is a cent~l mold overflow channel 149 st mold entry, to reduce the risk of molten
metal j~ g the entry junction between wheel and outer mold wall, should o . _. nO .. ~ - 1 ~ ~ - occur
during casting. The b-' ~ ,g assc..ll,ly is baset upon an external support frsme, to locslte and control
the force of nanged rollers 114 agsirLsl ~-' E track 115. Rollers 114, in tum, sre rnounted with
C4 but csptured with~n ~ lio.~ nange 1 16, thus providing for retrscting the s~ c rsdislly~5 outwsrd and off the wheel to hold them in eCsen~ y fixet position when desired for mold
i_,
~ ~, ~' _ r of wheels snd the like.
This segment e .~ ~ ~ includes ' ~ -' rsdiD.I ~ ~ of trsck fo~ 15, in view of
the much lower cost of re -~ ~ ,1 ~ E used outer ratius mold wall shoes 112 sRer use; in c ~ r '- Wilh
.~,lr ~ wilh ne w ones. Adj-~c~in~ scrcw 122 effects r ~ -nt of pillow blocks 121, to be held in
20 position by locking screws 123. In order to avoid potential a~cial segment yawing snd vil.. ~, one of
thefollowers 15ofescho~ Cpii isspring-p..,l~ ub~ bywsyof~ 1, spring
124 acting between cap 125 and lhc facc of linear bushing 126, thus - ~ ~ c -- running
contact bet veen flanges 22 and inner mold cdges 94. Sid~ 1, ' follow~ rollers, having onc of each pair
spring or fluid pre-loaded is a more e' ' ~ ~.al.._ nol illustraled. A single i ~. ' hinge-
25 coupling z~ ly 120 connects adjacent ~ ~ togcther, camprising opposed spl ~ - ' plain ~rust
bearings 117, th.. g against end nanges 82 Ors-~ nt~: 90 confined by brl~ . ass~ bl~ 118
and at an r ~ ~1~ tistance of s~p~ ~ bctween nan,ses 82, and also ~ pre-load spnng
119 wilh spring rate force s~firient to eli - clc.u, ~ and any bac~ h, whilst allowing both
h ~ and angulDr mi~ i~ment between " ' As applied to mold segments 10, in orter to
30 ~ mold shoe tllermal ~ s in thc evcnt lhat adjacent mold shoe ends are closely butted
together at st~rt-up. Belleville s~.ulg-wpshcrs are ap~,..",. - 'y ulserted betwo~ the nuts and bearings
117, A~ si~d to balance the o~ ag force of sprin~ 119, and with r ~ - - ~' travel s~ff - ~ to
~ ' ~ the ~ after start-up.
CA 022607~8 1999-01-18
o ~
.' ' ~ ' r7 " ~ 7 ~ ~ --
Fig. 17B also illustrates the variation of a contoured transversè prof~e of Vouter-radius mold wàll
112, in which side faces 18 are e ctended past clearance 17 into a reeess of outer mold wall shoe 112. This
elimin~tes the acute angle at the seetion corner entering into gap 17 and also allows a rounded corner 127
of the cast metal section. As otherwise illustrated to be flat, any metal flash into clearance 17 between
5 shoe and wheel oeeurs at the seetion comer, rendering it diffieult to hot roll or e~ctrude without introdueing
lap surfaee defects or the like, whereby wheel-and-band casters usually mili vffthe corner flash prior to
hot working. Contounng of the outer mold shoe face also e~ctends the range of shapes and sizes whieh can
be cast.
Flexible band closure casting wheels commonly used for casting eopper and ~lumimlm billets and
10 rods normally utilize a mueh larger seetor of the wheel than those for steel, that is, most cnmm~-nly, entry
is at 1-2 o'cloek and e~;it at 9-10 o'elock position, rather than 3 and 6 o'elock. Fig. 19 illustrates the
invenhon as applied to such a wheel, and with segment balancing effected by an air cylinder 145 mounted
within a square tube 146, the e:itension of which carries the segment b~ ncing rollers 114, and guided by
sliding bearing pads 1~4 riding against the inner walls of another square tube 147 fi~ed to machine frame
15 148. Ossillator crank arm 99 transmits osci!lating motion to mold segments 10. ~s ,ener~ted b~ cscil'ltor
drive assembly 156, which is also supported by fi~ed machine frame 148. Figs. 20, 21 and 22 illustrate
details of the segment balancing units as appropriately cantilevered out from a backing frame also
supporting the main casting wheel hub and bearings. Please note that piping and wiring and the like is
omitted from Figs. 15-22 for clarity.
Fast casting speeds require rapid mold closure oscillation, towards m~int,lining sufficiPnt negative
strip with minimal surface osei~ tion marks. Figs. 23 and 24 illustrate a suitable oscillator, in which
housing 95 carries bearings 96 for rotation of drive shaft 97 bv means of adjustable speed hydraulic motor
98 as an altemative to air motor 74 with gear bo~c and belt drive 75, as illustrated in Fig. 19. Eccentric
cranic e,ctension 99 revoives around the center a~cis of shaft 97 carrying connPeting rod dnve bearing 105.
In order to adjust the stroke length as infli~tPd by the graduated index 155, location ring 154 of
cantilevered stub shaft 150 is rotated by nut 151 and locked at the desired stroke length by bolted locking
plate 152. Crank 99 may be connPeted directly to mold segment wrist pin 153. Thus, a sinusoidal
reciprocating osei~ tion~ of selected adjustable stroke length, is tr~nemitted to the mold segmPnt~.
Figs. 25, 26, 27, 28 and 29 illustrate additional or alternative embodiments ofthe roller segment
apparatus 90. The cr~nt~inmpnt roller positionin~ and pressure-adjustrnent assembly 127 eomprises drive
eCcpntric disk 137 and driven eeeentrie disk 138 whieh are equally eeePntnc to roller shaft 84 and keyed to
~ it by parallel cross keys 134 and 135, as
-13-
p~AE~
CA 022607s8 1999-01-18
W 098/03286 PCT/CA96100473
fixed by dowels 136, thus comprising a rigid f ' ~y to maintain parallel rotation of thc shaft 84 axis
about the axis of disks 137, 138. C~: ~ idler roll~ 69, as s.""~ by bearings 72, is then
about shaft 84 by L ~ -' contact with thc moving facc of thc cast mctal sec~ion. Cu~ t~;c
disks 137, 138 rotatc within ~ ~ ;c L ' )g 161 mo~ted within axidly alignet circular ~ i ~ in
5 oppositc box side wdls 13, and thc rotation of drivc c~tl.c disk 137 is cffcctcd by a rotary actuator
assembly. In the csnbodiment illustratcd, this cosnpriscs t shaft 162 jr ~"~ within bcarings 163 of
housing 164, which is bolted to side walls 13 with axis concc~lb,~, to disks 137, 138. S.'neumatic or
h, ' ' - cylinder 91, via crank arm 165, rotates shaft 162, which L - e 'Iy purc torsion force
to disk 137 by way of splined or sq~e shaft end 166 ~ the like. Thc c stroke of cylintcr 91 is
10 lisnited by ~ of thc rollcr 69 ~ against whecl rim tracks S,6. Thc le~a stroke limit, as
showr~ is adjustable by stop-screw 169, as carried on brackct 168 attachcd to housing 164, against pin
167 which rotates integrally with shaft 162. Operatcd pncwnaticalb, this provides for prcssure control of
rollcr 69 sgainst cast metal section surfscc 104 during stroke . ~,.., . ~ g for section ..,~ . . ~
~' -' and swfacc u~c" ' itics whilst -- e c~ .. Iy constant roll~ force. Al~. .~
15 O~ e with cylinder retracted or zero - air pressure, providcs for ~ ~ ;;t; ' only,
cven allowing the cast section to relense frosn the whcel, _ - ~" e to the setting of stop-scrcw 169. The
rolla segment r ' 1~ 90 iS adapted to providc combined air-watcr cooling via air fi~ 139 and
water manifold 140 fecding spray block 141 into air-most nozzlcs 142, as wcll as spray watcr only, onto
rollers 69 vi8 watcr nozzles 144. As shown, thesc s~ ; are not t '- i although they could be so
20 arrangedifdcesired. Segment-to-scE,...~ hingingandsegmentb-'- ~ e~ arc '~6 t~
those of the mold s~ 10, 8s illu~b_
It will be appreciated that a rotary wheel casting machine has been d ~ ~ ikd and " _ - ~ and
that ~ r ~ " ~ ant ~ - may be matc by Ihosc skilled in thc art, without t -ps i ~e from the
scopc of the .. deflned in the . r ~ ~ claims.
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