CA1282121C - Method and apparatus for cutting welding steel strips - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A method and apparatus for butt-welding steel strips using a laser beam are disclosed, in which opposite ends of preceding and succeeding steel strips fed continuously are cut and the cut end edges thus formed are welded by butt welding using a laser.
the cutting and butting at the time of welding are effected with one edge of the preceding steel strips adjacent to the opposite ends of the succeeding steel strips aligned to be parallel with the center line of travel of the continuous processing line.
When effecting the alignment, the preceding or succeeding steel strip is attracted by an electromagnetic chuck on a work table in the continuous processing line and is pulled by the chuck toward a reference block provided with an alignment edge parallel to the center line of travel of the processing line to bring the edge of the sheet into contact with the reference block. The alignment is done in this state.

Description

METHOP AN~ APPARATUS FOR l.ASER
CUT'rIN~ AND WELDING THIN STEEL ST~IPS

~IELD OF TH~ INVENTION

This t nventlon rela~es to a method and ~n ~ppar~us ~or cut~c~ng and weldlng steel strip~. Mo~e particularly, the invent~on concern~ a method and an ~pparatus for cut~lng and welding steel strip~ for a steel strip processin~ line, ln whl~h facLn~ end~ of precedlng and ~ucceeding steel strips are CUt ln the wldth-wlse direction and the cut surfaces are welded togsther as b~t~ su~faces to ohtain a butt ~oint whereby the re~uLtan~
~oi~ed steel strlp~ c~n be suhiect to con~nUous rolllng, stampln~ ~nd other processings, and ln whlch ~ the t~lme o~ t~e cu~tlng ~nd b~ welding o~ steel strips the acing ends thereof are cUt ~1th high ~ccu~c~ ~nd a~e butt welded by a la~er beAm, for ins~nce, wi~ch the cen~r line o~ ~he steel ~trips aligned to be ~ n re~ ster or pa~ailel ~lth the center ~lne o~ the processi.ng linet thus permltting high accuracy joining o the ~el strips and pe~rnittin~ ~ hi~h ~uallty wel~ed ~r~laet ~co be ob~a~ned.

ACKGROU~ OF THE INVENTION

Heretofore, in order to per~or~ rolling and other processing ancillary thereto on ~teel ~trip~ ~hereina~ter re~erre~ to as rolllng process~ng) in a steel strlp processing lin~, between two ~d~cent s~eel ~rlp~ con~inuously supplied to thc steel strip processing line, an end-to-Qnd connectlon is achie~e~ hy b~t~l.ng and welding ~h~lr opposite end edges. Also, s~ch procc~lng and rewlndlng, weldlng, ~lltt~ng and ~uttlng (herelnafter referre~ ~o as condl~ioning proce~lng) ~re performe~ on steal ~tr~ps o~
sSl~con steel, and then resultant steel strip3 are ~upplled as a produ~t to the customer. Especially, ~n order to obtaln a produc~ havlng ~ unit weight ~equlred by the customer, steel strlp~ are ~oined together by bu~t weld~ng, ~here~y obtalnlhg contlnuous steel strip~ havlng an end-to-end connection ther~n and cu~tlng contlnuou~ ~teel strlps as the produc~ havlng sa1d unlt welght and then ~upplylnq to the customer the produc~ in the . .

32~2 -- 2 ~

form of coll~ or ~he~ts. Th~refore, the p~oduct, withoue: ater-tre~trncnt of ~he w~ld portlon formed during such cand~tlon~ng processlng i8 d~l~vered to the cus~omer, so that lt ls r~quired ~o obtaln a weld por'c~on of hlgh quallty. Partlcularly, rom the ~tandpo~n~ of reducing pow~r los~, strlps o~ ~ilicon s~eel are re~ulred to ~B rolled to R th~ cknes~ o ~bou~ O.35mm or le~.
ThereSorQ, such ~hln steeL ~trlps are ~equired to be weld~
to~e~her before they ~re ~upplled to th~ custom~r. However, ~o such thln strlp3, 1~ ~s impossible to obtaln a weld portlon o~
h~h quallty, as ahove described, by edge-prepara~lon of cutting opposite ends o~ ad~acent str~p~ u~ln~ the prior ~r~ she~rlng technLgue and then by b~t~-welding tho resul~ant end edges th~reof by prlor ~rt arc weldlng, such ~s TIG o~ MIG~
Namely, in both the ~or~er case o~ rolling proce~sing ~nd the l~t~er cas~ o~ cond~tionlng Proce~ing betw*en ad~acent ste~l strlp~, ~he trailing end o~ a pre~eding steel strip and the lead~ng end of a succeedLng ~eel ~tX~p are cut by using the prior art shear welder ~ormlng ~ contLnuous proces~, and ~hen ~he cut end edges oppo~ed each cther ar~ caused to be ~utt-weld~d by the arc welding, i.e., ~rIG or MIG. In other w~rds, ln a contlnuo~s pro~essing llne construct~d by the prlor art ~hear welder, steel s~rlps axe caused to run fro~ ~he ups~ream to the do~n~tream, a~d the~e, ars provided ~lon~ thls flow of steel str~ps, a cutting uni~ and a welding unit of steel strips at flr~t end of ~hs s~e~ rip ~ cut by the shearin~ unl~ ~x~sting on the up~tra~m, and ~hen ~h~ strlp is ~ranserred to the d~wn6tream, wher~ ~he opp~site cutting ends between ad~cent ~tee1 ~r~ ps ~r~ butted arld welded by ~he arc ~elding tec~nique, ~uch as TIG o~ MI~ .
~ low~ver, in the aase c)f the arc we1dlng, i.e., TIG or ~It;, a larg~ thermal inf14ence zone ls generated and also the width o~
the weld bead tend~ ~o ~e large. The arc weldlng technique therefore 1~ unsu1table for butt-weldih~ pro~e~ses during conditlonlng proc:es~ing o~ thin steel strips such a~ slllco steel strip~.

... , . ~ ~

~2~32~2 ,_ 3 _ That i0, when th~ MIG or T~C arc weldin~ is u~ed during t:he conditionin~ proces~ln~, thln ~teel strlps wlt}l a weld portion of ~ood qu~llty cannot be obtained. Ther~ore, the ~oined ~tee1 strlp 1~ wo~lnd lnto the form of a coil without takirlg off the w~ld portion lncludlnçl the ~teel str1p. flaw8 ~re gen~ra~ed in th~
steel str~p, thuq gre~tly deteriorating the qUAllty of the product. For thl~ re~on, owing ~o Avold ~roubl~s wlth cuatom~r, lt ha~ bson ln practice to remove ~he weld portlon o~ the ~te~l ~trip, when the 3teel strlp i8 wound a~ ~ coil.
Recantly, hl~h performance la~r wel~in~ proce9se~ a~d la~r welders h~ve be~n d~vsloped, and a hish ~ual~ty weld po~ion c~n b~ ob~ain~d by u~ing the laaer weldin~ proces~. When th~ hiqh performance l~er weldin~ i8 ~ed for butt weldinq ~ur~ng conditlonlng proce~ing of a thln ~llicon ~teel atrlp, A
~ontinuou~ steel strip having a w~d portion of hlgh quality ~sn bQ obt~ined, 80 a~ to be wound in the orm of a coil without ~emovlng ~he weld portion. By 30 ~oing, no su~tantial flaw i~
genor~ted.
Fur~her, the ~assr weldin~ proceYs permit~ sufici~nt effQcts and great advantage~ ~o bQ obtain~ wh~n it iR u~od for butt welding during the condltionin~ proc~sing of ~ilicon ste~l ~trlps. That i8, the weld bead of ~he weld portion obtained by lR~er w~lding ha~ a very ~mall width and the weld portlon i0 ~ub~tan~i~lly fre~ from therm~l influenc~. This mean~ that it ~
no'c n~c~3ary ~ n a produc'c o f laser welding to remove the weld po~tlon on the ~oit~ted stael ~trip, which may be punc~ed out by the cu~tom~r~3 durln~ a continuou~ ~tamplng ou~ of pattern~ on ~:he ~heet, without ~,pplyinq any treatment to ~le weld po~tlon ky ~hem~oltro~. Thia point i~ very ~d~an~a~eo~s for th~ customer~.
Ac'cually, punchlng o~ 3illcon 3teel strlps 1~ ~Igu~lly proc~sed in high ~peed continu0~l9 ~tamplng eq~(lpment w~ch 1~ proved by thn cu~tomer. ~ho~efore, v*ry long ~ointed ~te~l ~trlp~ a~o strongly de~ired or incre~sing the punch efficiency on the ~id~
of the cU~tomer.
~ owever, th~ ad~antage of the efective la~el! welding ~8 not~d abov~ cannot be ob~a~ned ~imply b~ a ~ub25ti tution o a la~er weldlng torch in pl~ce of' the TIG or MIO weldlnq to~ch o . ~

32~
~, tho prlor Rrt lihenr ~elde!r. In othor word~, unles~ ~dg~
pr~parat~on by cutting oppo~d ends of !-teel strip~ and butt:lng of cut end ~dge~ opposlr~ e~ch other i~ done with high accuracy, the de~lr~d efect~ o th~3 laser ~eldlng ~anno~: be obtRined, 80 that a hl~h quall~y w~ld portlon ~annot be ~b~alned. ~or th~
~ake of rofnrencQ, a hlslh quall~y weld portlon which mee'c~ 'ch~
customor'0 detn~nd~l io deflned ~ f~llow~:
(~3 thnt weld portlon 1~ homogenou~ atld conforms to prcd~terminecl refe~ence, (~) thrlt m~hani~/~l charQct~rl~tlc~ oE we~Ld port~on conform~ ~o thoae declded by prod~termit~ed ~ef~renc~, ~hd ~ c) th~t the w~ld portlon i8 ~ree rom be!nd2l or fAiLure of ~llgnm~nt of ~nd edge~ of r~tf~ trip~ ~i.e., fallure of 811~nm~n'c mean~ that a line, wllich 1~ ormed by l~utted Rsld ed~es o ~t~el ~trips, 18 not conformity with ~ ~'cr~ight lina perpen~icular to the cent~3r llne o the ~hear welder).
For ~educing ore 108g, there i~ R trend for r~ducin~ th~
thl~kness of ~llicon ~eol ~tr1ps, part:lcul~r1y direct1on~1 ~tee1 ~trips h~ving crystaL11n~! ~nisotropy, f rom about 0 . 3S to 0. 30mm to about 0. 35 to 0. l~mm or below. The ~ma11er the thickness, th~
more difElcult lt i~ to cut steel ~trip end~ w~ th high accuracy and butt the cut end su~ace~ wi~h hiqh accuracy and withou~
o~mation of an~ gap.
Futther, wher~ ro11ing and h~nt-treAtmer~t are appl~ed to cold-rolled thin ~teel ~trips, which are rewound f~om a coilQd o~m, before beinsJ auppliod as a product, ~te~ rlpa to b~
rowo~lhd ~te ~olned togel:her by welding, in order to pero~m a contlnuou~ rol.linq operatlon. In thiE~ ca~se, in t~e pa~, by u~lnçl tho TIC, MIG and like welding protea~e~!3, the rewound aold rolleli sl:eol stripZ~ wer- ~oll~ed to ~ch othe~, but recently 1~ hA~ ~een t~ied to uae th~ 1~3er ~elding proceQs whlch featur~
h~gh anettgy del~s1'cy. Th~ rQa~os~ for this i9 the~ me al3 for ~ licon steel ~tr~.p~3. That i~3, with ls,~er weldin~ it i~ pon~ible to provid~ a~ 8mA1l laEler beam dlameter as up to about O.lmm. It 1~ thus po~slble to incre~se the ~nergy den~slty and ~educe therm~l in1uence, ~o that w91d beads having a flAt ~lurfAc~ can be re~dlly obt~lned.

_ .i,.,-.~
_. .. _ . ;~ -- ~2~2~
_ 5 ! -Thls mean~ that a laser ~eldthg petmltt3 welding of cold-roll~d 'chin atrlp~ havlng a thi~kne~ of O. OS- I . Omm, ~uch ~18 e'calnles3 ~teQl ~trip8 ~nd ~llicon ~'ceel ~trlp~. Such thln steel strip~ ~re ~ncap~ble of belng welded by the prior ar~ TIG or MIC
w~ldin~ proce~se~. ~v~n ln th~ ~ c~, howeve~, th~ u~ of ~:}~
l~oor w~ldinq require~ highly accurat:~ c~lt'clng flnd buttlng prlor to butt welding. Pa~tlc~ rly, 1~ mport~h~ ~o cut end~ of ~t~el s~r~p~ accurately along ~ ~tta~ ght 1~ ne perpendicular to the center llne of the E~teel strlps lrl conformlty with one of continuous proce~in~ lln~3 and eEfect ~ho buttlng of the cut end~
~uch a~ ~o~ to produc~ dep~rture ~om the ~lignm~nt of the end ~dga~ of th~ bu~ted Bteel strlp~.
To m~et the~ requiremehts, there llave b~n devolopad technlques of accur tsly cuttln~ ~nd~ of 3teel ~trlps and c~u~lng accurate butting of the ~ut end~ prior to butt-~eldlnq. One su~h tachniq~o i~ dl~clo~d in JapRne~e Utlllty Model ~aid-Open 57-102495.
N~mely, ln order to ~void departure frotn tha alignment of weld line formad by butt-weldln~, t.he ~u~ end edge~ of steal ~trlps ~houl~ be str~i~ht and perpendicular to the center lin~ o~
the s~eel ~ttlp~, l.e., perpendicular to ~he direotion of travel of the contlnuou~ process line. In ~ltlon, d~lr~ng ~utt~n~
resultant cut ed~e~ of ~tael ~trips, ~ ~tralgh~ nli~nment ~hould be formed between cut edge~ opposed each other. The JapAn~e U~illty Model Laid-Open 57-102~95 di~clo~e ~n flltgnihg devlco for securtnq one side ed~e of ~ steel strip ~uch that ~t i~ parallal to ~h~ center llne of the ~eel ~trip. Xn th~ Rllqnin~ d~Ylco, ~ ~lde guid~ e~ured to one ~lde of a wor~ table at ~ cutt~ng or welding po~ltion o~ a contlnuous proce~in~ line, ao that the ~ldQ ~ul~e la paral~el to the center lin~ of tr~vel of the contlnuou~ ptoc~s~lny llne. One side edge of the steel ~t~lp l~
urged aqaln,~t th~ ~de~ gutde, there~y maklng ~n all~nmellt o~ th~3 centsr llne o steel ~trlp w~th the center lltle of travel of the continuoua proce~sln~ line. Therefore, ill auc~l Ali~nment the c~ttlng or buttlng of the ~t~el .~trlp l~ ~one prior ~o weldlnq.

. . .

~X8~12~
. ~

However, ~lncs thls ~llqninq device moves the ~te~ trip with the p~e~ (co~veyor) belt in contact wlth the surface of th~
~teel ~trlp, pte~ 1aws ~r~ bl~ to be formed on the sutfa~e o the ~t~el ~trlp, particularly the surface of a very thin ~'ceel strlp, by the urging force of the pre~ bel ~ and mo~emen~ t~
in th~ wldthwl~ dlrectlon o~ the work ~abl~. F-~rther, w~l~n the 8te~1 ~trlp i8 very thln, i~ i~ llable to adhere ~o thq ~u~~c~
with the work t~ble on the contlnuou~ pro~e~ln~ llh~ "uch ~el on a ~hear welder. Therefore, lt 18 difi~ult to move the ~e~l 8trlp ln ~he widthwlse dlrect~on toward~ the ~id~ guld~ for aLlS~nment b~ p~e~slng agnl n~t the ~urac~ oE the st~el ~'crip .
Therefo~e, eyen 1~ thl~ alignlng device 1~ u~ed, lt 1~ difficult to obtain ~ weld portlon fre~? rorn any ed~e allgnm~nt ~epartU~e.
~ notlhg th~ coe~1cletl~ o rictlon between the pre~ lt and ~teel ~tr~p by ~ he coefflclen'c vf frlction t~etw~h the ~teel etrlp and th~ work ~ble by 1~2' the urglng f~o~CQ of tlle pre~ belt by N, and ~he weight oE th~ ~teel st~lp by W, the orce, wlth wh1ch the steel strlp i~ pulled by ~he p~ocesB belt, ~1 (N ~ W)~12 ~ N(1~ 2)-WII2 Thl~ relAtion means that in order for pulling the ~ceel strlp ~y th~ pres~ ~lt lt i~ necessa~y to n~eet ~ condi~ion ,~
grea'cer than ~
Fu~ther, ~lnce the weight W o~ the s~eeL ~t~lp t~rle3 with 'che thicknoss snd width of tha strip, ~t i~ necessary to ad~u~
the ut~ain~ ~orca N of the pr~Y belt. Furtll~rmore, with a thin st~el strip, an exca~ive pulllng force will cause a st~Qin of tha ~trlp after the ~de edqe t~lereo h~ been brought lnto conSact w1th the ~ido ~uic}e~ In 8uC:h a case, ttle ~de edge~ of the two eteel ~ip8 Will no~c be truly ~traiyht after ~ub~aquent cuttlng and bu~tinçJ. A d~ired accuracy o tlle ~oint ~chu~ cP~nnot be ob ta 1 nod .
In the mesntlme, ln order to 8top the E;teRl strlp as goon a~
on~ ~id~ ed~a tll~reof i~ ~rou5~ht into contact with the ~ide 5Juide o the work table, it may be contemp].ated to UE~ a ~lgh ~.2~
- 7 - !

accu~acy sen~or, ~ continuouo moto~, etc. Howeve~ ch equlpment 18 expenulve and pose_ many problem~ i~ prsc~lc~, ~o that it h~ not ~et been employed in practice.
!
SUMMA~Y OF THE INYENTION

A flr~t ~eature of the lnventlon re~ide0 ln ~ ~on~lnuou~
procas~inq llne, ln whlch ~cin~ end~ of pr~ceding ~nd ~uccoeding oteel ~trlp~ are c~lt and the cut end ~u~fAce~ are ca~3ed to ~but ~ ahutt~ng ~u~fQce~ and are ~Qlded ~lohg the abuttlng 1in~
form~d ~y. the abut~ng, ln that when cuttlng, abut'cln~ ahd welding ~cin~ ends of the stee1 stlrps, at the tlme of th~
c~ttlng or abutt$ng prlo~ to the ~eldln~, ~ither th~ pre~eding ateel ~trip or the suçceeding ~teel ~trlp is att~acte~ by ~n electromagnetic chuck in at least one wo~k tablQ in the contlnuou~ p~ocesgin~ line, and ~he electrom~gnetlc chucX i~
moved to pu11 the preced~ng or ~ucceedin~ steel ~trip until lt strike~ an ~d~e of a re~erence block diRp~se~ parallel ~o t~
cente~ lins oE the continuo~ processln~ line to all~n ona edge of the p~ecedin~ or ~ucceedln~ steel strlp to b~ parallel to the center line.
Thu~ ~ccordin~ to the lnventlon, ~t the tlmc of cutting and/or weldlng, the ~nderside of the ~teel strlp i~ attrActed by the electrom~gne~ic chuc~ and i~ pulled ~n the widthwisQ
ditection toward ~he e~o o the referencc block to ~lign the ~dge of the strip. Thu~, e~en w~th ~teel ~t~lp~ h~lnq a thlckne~a of l mm or les~, p~rt~cularly a~ thln ~ O.l mm ~n thlck~e~, lt 1~ pos~ibl~ to obtaln acc-lrate alignMen~ oE ~he edge~
A second feat~re of ~le lnvention rR~ide~ ln tha~ by moving the electtoma~netlc chuck tha prece~in~ or ~ucceeding ~teel ~trip i~ pull~d toward the reerence block ~xtendl~g p~all31 ~o th~
cente~ 11n~ o~ the continuo~ proc~gg~ng llne to ~sing an edge of the precedln~ or ~ucce~ding steel 3trlp lnto con~act wlth the reEerence block and that lmmediate1y thereaf~er ~he magn~tlc force of the electromagl~etlc chucX i3 ~d~usted by the ~urrent to C~Be a 81ip of the preceding or ~ucceeding ~teel ~trip ~ith 1~82~

re~pect to th~ electromagnetiC chuck, tllUB align~ng the edgo.
Thu~, ev~n wlth the ~teel strip~ with a tllicknea~ of 1 mm or le~, pArtlcul~rly a~ thln ~ O.lm~ in thlckne~, when th~ edge oE the ~eel ~t~ip 1~ ~rought lnto contact wlth th~ reforcnce blo~k, a 91ip 0~ ~h~ ste~l ~trlp wi ~h re~pect to th~
electromagn~lc chuck i~ cau~ed tl~rough ad~ustmentn o~ the magnetlc force of the electroma~netic chuck with Cu~rent ~d~tment, w~ereby lt i~ possibl~ to el~mlnate unnoce~
pullln~ orce ~pplied to the ~dge of tha ~teel ~rip ~o that no c~ain remainq~
A third feature of the invehtion re~ides in th~t ~hen cau~in~ tho abuttin~ o tha ~o cut end ~urf~ce~ oE ~te~l strlp~
prlor to welding the end suraces wlth ~ w~ldin~ to~c~ ~n ~h~
w$~thwlse d~re~tion oE the ~teel ~trip~ in the con~inuous proc~s~lng llno, the fac~ng end of one oE t}le s~eal ~trip~ 1~
att~cted and held by an electromagne~ic chuck up~tre~m or downstream the torch runnlng line, on whicll ~ide the torch runnlng llne i~ no~ contained, thR f~Cihg end o~ th~ oth~r ~teel ~tirp i8 r~lsed 80 that tho cut end sur~ce i5 directed obliquely ~nd downwardly toward ~he cut end 6urface of the other ~te~l ~trlp, and in thi~ at~,te the a~utting surf~ce~ of t21~ two ~teel Jtrlp~ a~e cau~ed to abut. Thus, according to the invent~o~ fo~
~tt weLdln~ ~ha ~aclng ends of the precedinq or ~ucceedlng 8te9 atripn, the preceding 3teel strip with t~le cu~ ilin~ en~
~urfac~ can be held ~nd ~agnetlzed by the electro~agnetic chUck p~o~ded on the ~lde, which 1~ ~ee from the torch ~unning llne, wlth t~e cut end sut~ce a~ the abu~tihg ~urface in regi~ter with th~ c~nt~ lin~ of the cont~nuoun proce~8ing lln~. ~h~n, the ruc~e~dlnq ~t~ t~p with the cut leading end i~ ral~ed by su~tAbla mean~, ~.g., ~ roller, to direct the cut end ~urface at t~ leading ~nd obliqu~ly dowl-wardly toward tlle end ~ur~ace of the prec~ding ~tael ~rlp. Slnce th~ trailtng end of the p~ecadln~ ~teel strlp l~as b~en magnetlz~d by the electrom~gnetlC
chuck, whan the ~ucceedin~ ~eel 8~rip i8 ~oved ~uch the butt surface at lt~ le~dil~g e~ dlrected obliqu~ly and ~ownwardly flnd t~e bu~t aurfac~ appro~che~ the but~ sur~ace ~t tlla trallinq ~nd o tho prscedlnq ~teel atrlp, the butt ~urface 1~ pulled and 2 ~ ~ 2 a~tr~c~ to the butt surface o th~ preceding n~e~L ~trlp, whereby it is po~ la to ~btaln a butt ~Oillt whlch 1~ in Accurate r~lnter wlth tho runnlng line of the weldlng to~ch~
A ourth feature o the lnY~nt~on re~ld~ in ~h~ a movabl~
work tabl~ movable ln the dlrection of the ~tQ~l ~tr~p eecllr l~n~ 1~ provided ~ on~ o the wor~ table~ ln the continuous prvces~in~ lin~ ~uch that it ~8 capable of revolu~lon w~th r~pRct to a point of intarsectlon between one reference ~urfac~
of the mov~bl~ work ~able and a runnlng line oE the weldlng or ~uttlng~w~ldlng torch, ~nd ~t lQa~t two optic~l ~nla~men~
devlce~ ~re pr~vided on the ~ovable work t~ble for optically ~nl~ging t~Q oppo~lto 2nds of tha but~ line form~d wit the ~buttlng of th~ c~t end ~urf~ce of tho tWG ~teeL ~trlp~ ~nd ~re con~tructed ~uch that they are rec~procable ln a dir~ctlon p~rpendicu~r or ~ub3tant~ally perpe~dic~lar to the runnlny lin~
o the two steel 8trip9. Thu~, alignment can be monltored by optlcally enlarging the opposite end~ oE the but~ llne wl~ tho opti~l enl~r~ement device~3. Partlcularly, when ths opti~l imag~ i~ p~ocesned w~t~ an i~a~ ~en~or, ~hB aliqnm~ht can be dene aut~matlcally.

BRIEF DESC~IPTION OF THE DRAWINGS
Fig. l ~ B a ~ide ~lew 8howing a cut~er/welder utilizlng la~0r b~am in ~n embodiment of the in~entlon;
Flq. 2 1~ a ~sont view, partly ln ~ection, taken along ~r~ow line A-~ ln Fi~. 1 Fi~ 3 1~ a 31do vlew, ~howlhg ~ ex~mple of the ~teel strip ~eed~r;
Fl~. 4 i~ a trahsver~al ~ection~l vi~w, ~owing the 3teel B~tip fead~r shown in ~lg. 3;
Elg. S ~ ~ pla~ vlew ~howlnq an example of align~ng uAlt~
~onst~ tutinq part oE the cu~r/weld~r ~hown in ~ig. 1;
El~, 6(a) to (e) are views ~howing ~ucce~ive ~tep~ of cuttinq, CAU~ing abut~lng and weld~llg o~ 8teel str~p~ ~ccordlng ~o the inven~lon~

~L28~

i F1;1. 7 i~ a sectional view showin~ a cutter/welder utllizing a l~or be~m in R diffe~nnl~ embodim~nt of the lnventlon; alld Flq. 8 1~ a plan view ~howin~ an example o~ allghinq unlt~
con~titutlng pAtt of~ the cutter/welder shown in Fig. 7, I~ETAILEp DE:Sc~I rT ~
~ he invent~on will fir~t be ~e~crlbed by referencM to the fl~ur~, Refo~ring now to E ig . 1, referen~:e numcral 1 dc~ignate~ a pr~cedin~ steel ~trlp, and num~ral 2 nucceeding ~tenl ~trlp.
These ste~l etr1p~3 1 and 2 are cor~s~qu~ntlvely fed by ~ p~lr of pin~h rolle~ 3 and 4 ~o a cutter/welder whlc~ c:on~tltutes p~t o n ~ontinuous proco~ing 1 ln~3. Th~ cuttor/welder include~ ~
cu~tlng unit 5 and a welding 'corch 6 provided ~n ~h¢ mentionQd order rom the upstream Qld~. Alig~ling unit!3 7 to g, ~9 ~hown by dashed lines in Fig. 1, are prov~ ded be~ore, bett./een and ~f~r tho cu~cting unit: S and ~elding torch ~ in the dire~tion o~
travel of Bteel ~tripn. Detailed con~tru~tion o~ ~hc ~ligning unl t3 t ~o 9 i ~ shown i n Fl g . 5 .
In the cutt~ng and weldln~ operation, one side edqe o the precedlng steel sttip 1 ed by the up~tre~m side plnch roller~ 3 and 4 ~ 8 positloned by t:he ~llgning uni~ ~ qUcll that one ~id~
edge is paralleL to the center line of travel of the cont~nuou~
proc~sing llne C-C ( Bee li'ig. S) . In thi~ state, the tra1l~ ng end oX ~he p~ecedlng ~teel 13trlp 1 is cut by ~h~ cut~lng un1t 5.
After the cuttlng, ~he pr~cedinç~ ~te~l ~t~p 1 13 u~he~
trRnsportqd by a movable c:l~mp lO to the dowhstream ~ide to be ~toppQd when it~ cut ~nd ~dg~ la come~ to a po~ition behe~th t~e weld1nq torch 6. E~neAth the w~lding torch 6, one ~ld~ edge of th~ precedin~ ~teel strlp I i~ po~itlon~d by tlle un~t ~ to mak~
it par~llel to the cen~er line C-C of the~ continuouE~ proc~31n~
llne (~e Fig. 5). Al~o, tha cut end edg~ la of ~;he prec~ n~
~eel strip 1 i~ brought in conformity wlth ~ line 6a 1 se~ Flg.
S) alorlg w~ich t}le we~lding to~ch 6 is move:l hy c~u~ing moveme~2t of a work tablo 13 ben~Ath the welding 'corch 6 it2 t;:h~3 dl~ct10n o~ f~ed ln the con~cinu~u~ proce~ln~ line arld ~ o re~volutlon o the wor~c table 13 about A ~evol~lng ~ect~on 21 ( ~ee F~ g. 2 ) .

~L2~32~Z~

After the preceding steel strip 1 has been set in this state, the succeeding steel strip 2 is fed by the pair of pinch rollers 3 and 4. The leading end of the succeeding steel strip 2 is positioned by the aligning unit 7 such that one side edye of strip 2 is parallel to the center line C-C of the continuous process line. In this state, the leading end of strip 2 is cut by the cutting unit 5.
Subsequently, the succeeding steel strip 2 is further fed by the pair of pinch rollers 3 and 4 to the downstream side, and beneath the welding torch 6 the leading end of the succeeding steel strip 2 is aligned by the aligning unit 8 such that ane side edge of strip 2 is parallel to the center line C-C of the continuous process line~ Also, as shown in Fig. 6(d), the cut end edge 2a of the leading end of the succeeding steel strip 2 is directed downwards for butting against the cut edge la of the preceding steel strip 1 having been positioned to be in conformity with the torch running line 6a (see Fig. 5). In this state, the butted end edges la and 2a are butt-welded together by driving the laser welding torch 6 along the line 6a.
As shown in Fig. 1, a plurality of work tables 11 to 14 are arranged along a straight line constituting a feed path, along which the preceding and succeeding steel strips 1 and 2 are fed. Of these work tables 11 to 14, th~ work table 13 which is disposed underneath the welding torch 6 is capable of being moved in the direction of the continuous processing line, i.e., feed path, and also revolved about the revolving section 21 (see Fig. 2). By causing the parallel movement and revolution of the movable work table (hereinafter referréd to as movable table 13) after one side edye , ~ .

~2~2~

of the preceding steel strip 1 has been aligned, the cut end surface la of the preceding steel strip l can be finally disposed such ~hat it is accurately in register with the torch running line 6a, which is positioned to be precisely perpendicular to the center line C-C
in the continuous processing line.
In the cutter/welder which constitutes part of the continuous processing line, the upstream side cutting unit 5 is usually provided as a shearing unit with a shear or the like or a fusion severing unit for effecting fusion severing with a laser beam or a cutting unit for effecting cutting with a grindstone. The welding torch (hereinafter referred to as the torch~ 6 is provided on the downstrea~ ~f the cutting unit 5. At this time, the torch running line 6a is positioned such that it extends in a direction precisely perpendicular to the center line C-C of the continuous processing line (see Fig. 5), i.e., the direction of running of the preceding and succeeding steel strips 1 and 2, and then the torch 6 is provided such that it can run along the torch running line 6a.
The movable table 13 which is provided underneath the torch 6 is constructed such that it can undergo parallel movement in the direction of running of the preceding and succeeding steel strips 1 and 2, i.e., along with center line C-C of the continuous processing line. Also, it is provided on a revolving table 20 to be noted above such that it can be revolved about the revolving section 21 (see Fig. 2).
The torch 6 is constructed such that it is vertically movable and can also run in stringent register with the torch running line 6a positioned to ~e perpendicular to the direction of running of the preceding and succeeding steel strips 1 and ~ fed ~ 13 -along the center line C-C of the continuous processing line. On the opposite sides o~ the torch 6, securement clamps 16 and 17 are provided such that they are verkically movable~ on the movable table 13a back bar 15 is provided in register with the torch running line 6a (see Fig. 5). Downstream and upstream side electromagnetic chucks 18 and 19 are provided on the opposite sides o~ the back bar 15. Thus, in the butting and welding operations, the trailing end of the preceding steep strip 2 and the leading end of succeeding strip 2 are held from their end sur~aces by the securement clamps 16 and 17, respectively. On the movable table 13 the trailing end of the preceding steel strip 1 and leading end of the succeeding steel strip 2 are held by magnetiæation by the downstream and upstream side electromagnetic chucks 18 and 13.
The mechanism for causing the parallel movement and revolution may have any desired construction. To ensure accurate butting, the revolving table 20 is constructed, as shown in Fig. 2 such that it is capable of revolution about tha revolving section 21 and the movable table 13 can undergo parallel movement on the revolving table 20.
The revolving table 20 is disposed on a stationary table 37. On the stationary table 37, the revolving table 20 is capable of revolution about the intersection between one reference side surface 13a of the movable table 13 and the torch running line 6a (see Fig. 5). For example, revolving table 20 is capable of revolution.
To permit precise adjustment o~ the parallel movement of the movable table 13 or revol~tion of the revolving table 20, a moving mechanism and a butted state detection mechanism may be ~Z82~
- 13a -constructed as follows.
As shown in Fig. 2, of the work tables 11 t~ 1~
constituting the feed path of the preceding and succeeding steel strips 1 and 2, i~ e, the running path of the continuous processiny line, the movable table 13 is straddled by a gate-shaped frame 22 provided on a base 26. A top beam 22a o~ the gate-shaped frame 22 is provided with upper and lower tracks, e.g., rails 23a and 23b, extending in its longitudinal direction. The torch 6 is provided such that it can run along these rails 23a and 23b. A laser beam is ~upplied ~rom a laser beam generator 25 to the torch 6, and it is converged to a diameter of about 0.1 mm to effect butt welding of the steel strips 1 and 2 by using the laser beam. A laser beam path 24 is provided extensively along the beam 22a of the gate-shaped frame 22. The torch 6 is coupled to the front end of the laser beam path 24, and the laser beam generator 25 is coupled to the rear end of the laser beam path 24. Thus, the laser beam emitted from the laser beam generator 25 is fed through the laser beam path 24 to the torch 6. As the torch 6 runs along the torch running line 6a (see Fig. 5), the laser beam path 6a is extended or contracted, whereby the two steel strips 1 and 2 are butt-welded by using laser beam.
A mechanism for raising and lowering the downstream and upstream side securement clamps 16 and 17 may have any structure.
Usually, the mechanism is constructe~ _ /
//

~L~2 !32~2~
- 14 _ mechanlsm. ~esld~ss, 1~ ~8 construct~d th~t it opora~ tl ~t"
in~erlock~d r~lation to the movabl~ table 13, revolvlng tAble Z0 ~nd ~tation~ry table 37.
Mor~ ~paciflc~lly, the two ~ecurem~nt clamp~3 16 ~nd 17 m~y bo con~tructed to ha~fe thel ~ame constructlon~ and ~he ral~lng ~nd lowerin~ mech~ni~m may 1~9 provld~d independen'cly on ~ACh ~ocurement cl~mp. Fig. 2 ~how0 ~ typlcAl construct:lon o the mechanium or rAl~lng and loworing the up~tream ~icie ~ecu~ment clamp 16. Tha mecha~ n con~lst~ of ~ pal~ of ~uppor'c pll~ra ~
pro-rld~d ~nslda the qnt~-sh~ped frame 22, cyllndors 2a mounted on tho re~p~tl~e eupport piller~ 27 and rod~ 29 driv~n by t~
operatlnç1 f luid of the cyllnder~ 28 . Tha l~p~tream ~lde aRcuroment clamp 16 1~ n~ou~lted on the ~op of tho rod~ ~g, and lt laed ancl lowered with the elongation and cont~ac~lon of tha rods 29. The me~:h~nism for ralslng ~nd lowerinq the downstr~Am Jlde qecuremen'c clamp, whlch ~B not shown, ha~ the 3~me cona~ruction.
To p~rmit ~volution of the revolving tabl~ 20 ~nd ~l~o p~rm~t movement of tho mov~ble table 13 along the ~evolvlng tabl~
~0, tho ~el~ olving t~bl~ 20 i~ provided on tho inner ~lde o~ t]lo p~lr E3upport pillRre 27 conetituting part of the r~i~ing~lowerirlg ~ache.nism. Rectilinear ~Liding ~earinq~ 31 are prov~cled on t}le top o the revolvlng tablo 20 and the bottom of the mo~rable tahle 13, respectively a~d bearing ralls 30 ar~ lnterposed between the uppor and lo~er trat~sl~tional bearing~ 31. Thus, the mov~ble tabl~ 13 i6 movod. along the ~volvlng ~able 20 in the dir~ction o~ runnlng o~ tt 1~ preceding and ~ucceeding steQl ~trlp~ 1 and 2, l . e ., the center llne C C o~ ~he cor~tin~lous proceEIsinq lin~ ~ ~ao Elg. 5~. At tho time o~ the but~clnq opQration, the movable ~blo 13 1~ mo~ed ~y ~light amount8 to br~n~ th~ butting ond ed~a la o~
tho precoding o~e~l l3trlp 1 ilstO r~3gister with t:he torch runnlng line 6a (~e ~ig. 5) E~nd IA180 make B but~cing line form~d bet~n ~hs opposi.te end edge~ of two 3tasl ~4trips 1 and 2 to b~ in re~l~ter w~t:h the ~orch running llne ~a. A paralle~l movem~nt unit fot CAU~lng A parallol move~nant of the movable t~blo 13, A~l shown ir~ F~.q. l, ~on8i8t8 o.~ a hUmeri~al control motor 32 provlded on ~;he ~evoLvlng table ~0 and R ba~ crew 33 coupled to ~L2~
I s th~ numerlc~l con'crol mo~or 32 . The end of the ~al 1 3crew 33 ia co-lpled to th~ movabLe ~bl~ 13. E'or ~hi~ ~e~son, e~en lf th~
ex~ent of parall~l movement or causlhq ~he tor~h ruhnlng l~ne 6R
~nd ~u~tlng line into r~ 3ter with each other i~ very ~ ht:, the nu~rlcal cont~ol motor 32 ~an be corresporld1n~1y drlvet~ to ~
nll~h~ ~xtant to obtilln ~ccur~ buttlnq o th~ t:wo cu~ ~nd ~dges 1~ And 2a.
A~ Inent~oned Above, the re~olvlng t~ble 20 i ~ chu~d to ndergo ~evol~ on El~out the ~volving ~ection 21, wh~ch ~a loc2ted at the inter~ection b~tween the rsferen~e side edge 13a o~ the m~ bl~ t~ble 13 ( ~ee Fig. ~ ), 1. e ., the edge pAr~llel to t~ nter 11ne of the contlrluous proc~in~ lin~, ~nd th~ torch running llne. The~ revolvin~ mecl~ani~m for revolving ~he table ~0 about th~ ~volving ~eGtion ~ of the int~sect~n, may co~s~
o~ a cyl~ndr~c~l baarin~ 34, a ball ~arew 35 ~nd ~ num~rical control mo~or 3~ More ~poclically, a0 ah~wn ln Fig. 2, the cyli~dric~l bearinq 34 i8 pro~lded between the revolvlng table 20 And ~atlonary ta~le 37, the baLl ~crew 35 i~ aliqned to ~he cylindrical bearing 34, and the num~rical control motor 3~ 1B
co~pled to the b~ll screw 3s. Ther~fore, even lf th~ revolutl~n cau~ed to brlng the torch runnlnq llne ~a snd but~ing l~ne lnto reg~ster wlth ~ch other i~ to a very light ~xtent, e.g., of the order o mlcron~, the numer~cal control motor 3~ ean ~e glven 8 corrs~ponding rotation.
~ urth~r, a~ wlll be deacr~ed later, it i~ nece~ary to obtaln p~rEoct re~ter o the buttlng llne with the torch running l~ ne 6a ~ ~ee Eig. S ) af ter th~ end edge~ la ~nd 2a o the preceding and ~ucceedlng ~te~l ~trip~ 1 and 2 ~ee ~iq. 5~ ~ave b~n but~d on the mova~le ~able 13. Thi~ is done by cau~ing parallel mo~m~nt and ~evolutlon of the movable ~abl~ 13 to a ~llght oxtan~. To deteo~ the extent of quch movement, ~t lea~t two optlc~l onl~gemsnt ~nit~ S0 and 3~ ar~ provided Eor optlc~lly enlar~lnq th~ two oppo8it~ en~ of the butt~n~ line. The~e t~o optlcal ~nl~rgement unlts 50 and 3B, ll~a the ~o~ch ~ are ad~pted to r~n ln ~ dlr~c~on porpendlcular to thæ c~n~er lln~ c-C of the continuous proce~sing llno (~e~ ~iq. 5).

8~21 ~ 16 _ More partlc-~larly, the optical enlargemeht unit~ 50 and 38 h~e the ~am~ COn~rUC~ierl and respectively cons~s~ of microscop~ 31a and 38a, camer~ 37b and 3Bb and mov~ble ~addle~
37c and 38c. To perm~ ~ runnin~ of the movable ~addles 37c and 3~c in a dlrection perpendlcular to ~h~ cen'ce~ lin~ C-C o~ the ContinUO~lB prôce~lng llne, the s~ddle~ 37c and 38c ars engaged wlth tha rail~ 23A ~nd 23b of the torch 6, ~ ~hown ln ~lg. ~.
~t ~ ~ po~slble to ~r1ve the movRbla ~addle~ 37c and 313c lnd~pendelltly ln~ead of cau~ing thoir movemen~ alon~ the ~m~
rallff 23a and 23b as for to~ch 6.
The mov~ble ~l~mp 10 or cau~lnq tha prec~din~ st~l str~p 1 to the down~tr~a~ ide aftar cut~ing ~he l~railing ehd of the ~rip 1, a~ ~hown ln ln Fig~. 3 and 4, con~ s of a palr of movn~le clamp ple~e3 lOa ~nd lOb. The upper clamp piece lOa can be raisod and lower~d by ve~tical movement cyllndQrs 39 provld~d on th~ oppo~i,te ~i~a~3 o th~ lower clamp plecn lOb. Th~ lowe~
clamp pioce 10b ha~ ~ comb shaped top port:ion, w~ich 1~ as~embl~sd to ~he wo~k ~able 14 which h~s a dralt~-boArd-llk~ ~h~pe. The comb-~hapod top portlon of the the lower clamp piec~ lOb sllsll~tly pro~ct~ upwards from the work te~ble 14. The preced~ng st~ol ~rip 1 thu~ can be ~moo~ly clamped bctw~en t~le upp~r and low~r clamps 10~ and 10b witho~lt o~tructlon of itB movement.
A mechanism or mo~ g th* movable clamp 10 consist~ of nwl~eric~1 con'crol motor 4~, a ball scr~w Js2 and ~ pair of b~arinq~ 41a and a bearlng rRil 42. Therefo~e, e~sn ~f the extent of movement of the mov~bl~ clamp 10 i~ very ~llgh~. e.g., o~ the order o~ m~cron8, ~he rotation o~ t~le moto~ 40 can be con'crollad ~:orr~ponAihgly anc~ tlle movable c1amp 10 can be mo~ad ~ccurR'c~
Th~ cutting unit S for cutting the encl~ of the precading and ~ucceedlng st~eL ~trlp~ 1 and ~ ~ u~ually con~l~ts of a pa~ r o, upper and 10WQ~ b1ede8 S~ and 5b, as ~howh in Fiq. 1, ~nd whieh blade~ can c:u~ the ends by using she~ring . I n~te~d of ~uch cuttln~ tlnlt u~ln~ ~hear force lt iB al~o po~3sible to conDtrus:t t~e cuttlng.un~t S ~o ~!3 to effect melt~.ng and cut~lng by using A
Innor b~am, an el~ctron be=m or other l~eat oourc~=~ A ~crl~p .::

~L2~ L2~

removal unit 43 may be provided, if necessary, to remove scrap produced as a result of the cutting operation from the work table 12.
The three aligning units 7 to 9, which are provided in the mentioned order from the upstream side as shown in Fig. 1, ha~ the same construction as shown in Fiy. 5.
As shown in Fig. 5, the aligning units 7 to 9 consist of respective electromagnetic chucks 7a, 8a and 9a and reference blocks 7b, 8b and 9b. The electromagnetic chucks 7a, 8a and 9a and reference blocks 7b, 8b and 9b can be moved by extension/contraction devices 7c, 8c and 9c in a di~ection perpendicular to the center line C-C of the continuous processing line. When cutting the trailing end of the preceding steel strip 1, the aligning unit 8 is used as noted below. More specifically, the opposite side reference blocks 8b provided outside of the continuous processing line are moved by the respective extension/contraction devices 8c to a reference position, at which they are parallel to the center line C-C or the continuous processing line. Then, the preceding steel strip 1 is fed by the upper and lower pinch rollers 3 and 4, as shown in Fig. l, and the preceding strip 1 is stopped while trailing end of the precedin~ strip 1 is on the upstream side of the cutting unit 5 (only the upper blade 5a thereof being shown in Fig. 5). The central electromagnetic chuck 8a is partly incorporated into the work table 11. When the electromagnetic chuck 8a is excited at this time, the underside of the preceding steel strip 1 is attracted to the chuck 8a. In this state, the electromagnetic chuck ~a is pulled by the extension/contraction device 8c in a direction away from the continuous processing line in Fig. 5. The side lb of the preceding .~ . ..... .

~L~Z132~21 - 17a -steel strip 1 is thus pulled toward and brought into contact with the reference blocks 8b, so that it is aligned thereto. In this state, the side edge lb of the preceding steel strip 1 is position parallel to the center line C-C of the continuous processing line.
Thus, by lowering the upper blade 5a disposed perpendicular to the center line C-C in /

2~%3~

thi~ e, tha ~rall~.ng ~nd of the preced~ng ateel ~trlp 1 ir~ cu~
to ob'caln the cU'c ~3nd edg~ la as the buttin~ surfAce perpendicular to the center llne C-C.
Wh~n cu'c'clng the l~ading end of tho ~ucceedlng ~t~el ~trlp ~, on~ ~ldo e~ga 2b o it ~ ned by the ~ligr in~ unlt 1 ~hAt lt 1~ parnllel to the c~snt~r llne C-C. AgAln, ~ hls the and 1~ cu~ ln the 6ame m~nner a~ for t~le preceding ~
atrlp 1 to obtain the cut ~nd edges 2~ perper~dicul~ to the c~3n~er l~n~ C-C at the leadin~ end o the ~ucceedlng steel strlp 2. Further, when the cu~ er~d e~e la ~nd 2~ of the B'C~lel 8tri.p8 1 and 2 a~.~ butted on th~ mov~le table 13, thQ edga~ 1~ ahd 2b Rre mad~ parallel to the center line! C-C. At thls tlme~ the precsdlhg ~nd ~ucc~edlng ~'ceel Bttip8 1 and 2 are alignQd by the r~3pe~tiv~ ~ligning unl~ ~ and 8.
When ~ligning the gid~3 sdg~ lb And 2b of tha ~teel eltrlp~
Wl~h the alignlhg unlt~ 7 to 9 ln the abo~te way, i~ i~ d~sired to ~d~U~t the magneSlc force~ of the electrom~qnetic chuck~ 7a, 8 ~nd ga ~uch a3 to permit ~lip of 'che el~ctrom~gnetic chucks 7a, 8a and 9a with respec~.'co the two ~teel ~tr~p~ 1 ancl 2 with 'ch~
sld~ ~dga3 1~ And 2b tl~ereof in contact Wlth t~le ref~rence blocks 7~, 8b and gb, thu~ allgnlng the side edge~ lb ~nd 2b oF th~
~teel strlp~ 1 ancl 2 to be p~ l to the centar l~ne C-C.
More ~pecif~cally, tha Bteel ~trip~ l and 2 are moved ln a dir~ction perpendic~slar to ~he center line C-C wlth ~he~r under ~lde ~ttractad t~o t~le electromagnetlo chuck~ 7a, 8a anà 9~ by uslng ~lectrom~gnetic force~, ~nd thereby the slde edg~ lb ~nd 2b of the ~teel ~trips 1 and ~ ~re bro~ght into contact w~h the roerence block~ ~, 8b and ~b provlded on the oppo~ltQ 31de~ of t~e elec:tromAgnetlc chuck6 7a, ~a and ~a. I~ 'che magnetlc force~
o~ the elec~omAgnetiC chUclt~ 7~, 8a an~ ga 2~e exces~ive At thl~
tlme, tha ~de edges lb and 2b of the ~teel ~trlps 1 anrl 2 are linble to ba ~t~ ed by the pulling force. In this ~ e, ~h~
~lde edgeel lb and 2b cannot be accurately aligned.
On the contrary, if ~he magn~iC force~ are ln~ufflcien'c.
~he ~t~el ~trip~ 1 ~nd 2 cannot he moved against the frictional re814tance. Further, ~he pulllng force ba~ed on the magnatlc ,10 ~Q~
~g,~ol~lL~L :
I q _ forces o tha electrom~gn~tlC chucks 7Q, ~a ~nd 9a are varled accordlng t~ the thickne~ o~ the ~te~l ~trtpa. That 1~, wlth the same cu~rent ~upplle~ to the electromagnetic chuck~ 7A, aa and 9a, the pulllng orce that 1~ produced i~ larg~ ~f thlckn~ss o~ the ~heet 1~ la~ge, whll~ lt i9 ~m~ll lf the thlckne~ o the sh~et i~ ~m~ll. Mennwhll~, th~ ~ide ~dges lb ~nd 2b of the ~tecl strip~ 1 ~nd 2 are not ea311y ~tr~ined whon the thlckne~ of th~ steel ~trips 18 l~rgo, whiln they nr~ ea~ily s~t~ined when the thickne~ m~
Summln~ up, the prope~ pulling fo~c~ ~hould be ad~u~t~d to ~e in A rRnge graAt~r th~n the pulliny or~e with whlch 'che ~teel ~trlps 1 and 2 are mov~d to b~n~ the nide edg~s lb and 2b ih'Co con~Act ~ith the reerence hlocks 7b, ~b and 9b, b~t lea~ than the p~lling force with ~hich the ~ide e~ge~ lb a~d 2b a~
ctr~sed in contact with the reEetencs block3 7b, ~b and 9bo Therefo~, when pul~ing the ~teel ~trlp~ 1 ~nd 2 wi~h tha ~lectrom~gnet~c chucks 7~, 8a and ~a, the magnetlc force~ oE the elec~om~netlc chuck~ 7~ nd 9a are suitably ad~u~ted a~
aoon a~ ~ach o the edg~ lb and ~b i3 b~ought in~o contac~ with ~ome of the reerence blocks 7b, 8b and 9b. In tht~ way, the ~te~l ~tr1ps 1 an ~ are al1qned w1th re~pect to the elect~oma~netic chucks 7Q, ~ ~nd 9a. Py align1nq t~e ~id~ edge~
lb an~ ~b with ~e~pect to the ~teel ~t~ip~ 1 and 2 ln thi~ way~
the pulllng orce 1~ h~ld in an adequ~te range at the t1me oE ~he cont~c~, ~o ~ha~ the ~id~ ~dge~ lb qnd 2b of the steel ~trlp~ ~
and 2 ~an b~ ~lign~d wl~houS gene~atlon of any stralI~. Until the 31de Qdg~s 1~ and 2b are brought into contac~, the p~lllng Eo~ce can ba lncre~sed, ~o thAt tho steel ~trips 1 and ~ can be mo~ed 1~resp~Gtiv~ of th-3ir wel~ht and thlckne~s.
~ hi~ ~ffect i~ p~o~noted by ~he pro~l~ioh o the referencQ
block8 7b, 8b, ~nd 9b on the oppoZ~t te side~3 of the oloctromagne~ic block~ 7a, 8a as~d 9a ln tl~e aligl-1 ng unit~ 7 ~o 9, ~ shown in ~ig. 5 9 and ~he ~1ds edqes lb alld 2b can be accu~ately allgned to be parallel to ~he center line C-C.
NAm~ly, ~hen ~he ~ido edge 2b of the ~ucceeding ~t~sl strlp ~ is brought lnto co~tact wi~h one o the oppo~l~e s1de reference block 7b, the pullin~ ~o~ce of tha electrom~gnetic chuck 7~ giv2~

-~L282~2~

to the aucceedi~ teel n~rip 2 a rotatS on~l mom~nt about on0 r~ferancQ ~lock 7h ~ontacti n~ the side edg~ 2~, by ~hlch rotAtlonal moment the side ed~e 2b of the ~ucceedln~ S~teel strip 2 i~ brouqht lnto con'cact Wl'ch th~ oppo~ite side reference bloc~s~
7b. A~ a re~ult, the ~lde edge 2b ~ 'ch~ uu~ceecling steel ~t~ip ~ le po~ltlonad parallel wlth tho cent~c llne C:-C. Wh0n ~ atrong pullls~g orce i~ ~ub~quel~tly ex*rted to the succo~ding nt~ol ~trlp ~, a strain l~ liable to be g~rlerated in tho ~ide edqo 2b.
Howover, ~inca ~he magnetic forca iH ~d~ ted Wl'ch tho electroma~netic chuck 7~ A!~ nocn ~ the ~ucceedlng st~el ~rip ~
~f; brc~ugl~t ~nto corltac:t, a ~lldi ng of the ~ucceedlng ~te~l ~trip 2 wl~h r~opec~ to th~ alec~ront~S~nQtlc chuclc 7~ ~ cau~ed. Thu~, regardl~ of ~topp~ng t:he chucX 7a at a prope~ posl'clon, it le po~si~lo to aliqn th~ ed~3e lb of th~ ~ucceeding ~teel ~trlp without ganeration of any ~traln.
After each o ~he ste~l ~trip~ 1 and 2 has it~ OppOEli~Q ~nd cU~ by the ~uttlng unit 5, the re~ul~ant ~?dgeE3 la and 2~ ~ra ~oint~d toq~3thsr by butt weldlng on the movablo tabl~ 13 under the torch 6. For obte.ining a perfect ~utting o~ end edqe la an~
2a, At the ~idQ of the mov~ble table 1~, there 1E~ pro~sided a roller 4~, whicl~ can be rai~ed and lowered by E~ v~rtic~l movement cyllnder 45.. ~ h the provlslon of the roller 44 in th1s way, ~t:
c~opera~e~ wlth ~hQ pair electrom~gnatic ~:huck~ and lg on ~h~
movab~e tsble 13 to cause 'che trai~inq end ~dg~ 1A Of the prec~dlng ~tee~ ~trip 1 to butt the le~d~n~ end edge 2a o the ~ucc~eding ~teel ~ ip 2 wlthout ~ny gap form~d betwe~n the two ond ~dg~
A'ce.r the, prec~ding ~t~eL ~'cr1p 1 hA~ been ed by 'che pair of plr~ch roller~ 3 and 4 and ~.tB ~ra~lln~ ~nd has been cut by ~
upper and lower blades SEI and 5b, the ~r.~p 1 1~ bro~l~ht to the welding po~itlon, i . ~ ., the movablo table 13 ag B}10WII in Flg.
6~a~. On th~ movable tabli3 13, tl~e rez~ul~an~ end edg~ of th~
tr~ ng end of the pr~cedln~ ~teel ~crlp 1 1~ bro~ght lnto regl~ter ~ith the ~orch running llne 6~, and the pracedlng ~tee1 strip 1 ie secur~d a~ th~ ~ po~ ion hy low~ring th~ ~acurement ~lamp pi~co 17 ~nd ~l~o by excltlng tho eleci;roma~n~ chuck 19, A~ shown ln Fig. 6(b), th~reby magnetiz1n~ the end edge la o~ the 121!3Z1 21 ~trip 1. Sub~squently, ~he ~u~ceeding 3teel ~trip 2 1~ ~ed by tha palr of pinch roller~ 3 ~nd ~ up to the cuttlng po~itl~n El~
~hown in Fl~ 6(b). Then, the lsacling end of ~che succeedlhg ~teel strlp ~, like ~he tr~illng and of thel preseding ~eel ~trlp 1, i~ cu~ by tha upper and low~ blac~e~ S~ ~nd ~b wi~h ~he edg~
allgned ~see Fig. ~(b) ~, and th~n the scrap 1~ rbn~ov~d by the ac:r~lp removAl unl~ 43 (see Flg. 6(c)). Subsequen'cly, ~h~
~ucceedlnq ~teeL ~trip 2 1~ ed to ~he dowl~stre~m ~lde by the p~ir of pinch rollers 3 ~nd 4.
At this tlme, t:he roll~r ~4 1~ ralnQd when ik 1~ p~s~ed ~y the lead~n~ end of the ~ucce~dlnq steel 3trip 2. ~ho roll~r 44 ls prov~ded At the upstr~a~n nlde of the torch 6 ~nd i8 ~d~lptRCi to b~ ~a~ed ~p to a level correspond~ ny to the thlckne~ o~ ~he te~1 ~tr~p~. For example, when the thlckne~ ~t3 abou~ 0.20 rnm, th~ levdl i~ ad~u~3ted to ~bou~ 1 ~m. SincR the ~ucceed~ng ~te~l ~trip ~ ~ v~sry thln, e.g., 0.35 mm or 1e~38 ~n l~hlc~tne~, b~
ral~ins the rollor 44 th~ end edge 2a of the leadlnq ~nd 1 directod obl~qu~ly downwEIrd~ ~ BeO Fig . 5~d) ) . In thi~ te, the ~ucce~din~ ateel ~t~.p .2 i~ fed by the pair of pinch roll~r~ 3 ~nd 4 ~ch thAt the end ~dq~ 2~ at th~ le~dlng end ~llde on the movable tQble 13 toward the! end edge la, without rai~ing the ~nd eclge 2a from ~h~ rface of ths Inovabl~ t~ble 13.
he aua~dlng r~ 1 ot~ip 2 i~ f~d in ~hi~ WA~ nd edge 2~ of th~ succeedln~ el ~trip 2 ~lidin~l on th~ mov~ble t~ble 13 approach~3 tho ~nd adge 1A o the tra~llng end of the proc~ding ~te~ ip l as ~hown ~n Fig. 6(d). ~inc~ ~h~ trailing end o the prece~ding ~t~el ~tr~p 1 h~ be~n magnetl~ed by th~
aL~ctroma~n~tic chuck l9 ~8 no~ced above, the end edge 2a 1 e a~trQcted by the end edg~ of precedln~ E~tr~p 1, ~nd perfe~t clo~o contac~ bR~ween the two end cdge~ 1~ and 2R can be obtAlnod. More ç~peclE~c~lly, Elince ~he end ~?dge 1a of thn traillng end o~ th~ preceding Dt:eel t~trlp 1 ha~ been maqnetl~ed by the elec:~romA~netic c2 uck l9, the approachlllg end adge 2~ of the leadlng end of ~he ~ucceeding ~teel strlp 2 i~ atrongly at~racted in ~ downwarc~ly dlrected atate, ~o that it i~ po~lble to vbt~ln ~ parfect butSin~ wltho~t ~ub~tantial gap ~ormecl be~ween the two , ,,~, ,',1,~

282~2 ~nd 6dg~ 1A ~nd 2~. Af ter the completlon of the buttlng, th~
roll~r ~4 io lowered. Th~n, the ~ucceedin~ steel strip 2 ha~ ~t0 rea~ 8~hCO attrRcted by the ot~er el~ctromagnetlc chuclc 18, and lt~ front ~u~ace cla~ped by the 8ecutement clamp l& (~ee ~lg.
6(e) ), l`h~eaft~r, ~h~ ~orch ~unning lln~ ~ and bu~ing l~ne nre brou~ht lnto ragi~t~r by cau~ing paraLl~l mov~m~llt And revolutlon ot th~ movable tabla 13 wlth two enl~r~em~nt utllt~ 3~.
~n thl~ ~at~, th~ ~nd edge~ la, 2R ar~ b~tt-welded tog~ther by drlv~ng th~ torch ~.
N~m~ly, wllen butting t~ro ~nd edga~ 1A ~nd 2~ fo~med by cuttln~ OppO8~ te ~nd~ o~ pr~cedlny And ~c;eeding ste~ trlp:~ 1 and 2, it 12~ aom8tln~e~ thAt the two ~nd edge~ la ar~d 2~
o not flu~h but are stapp~d. E3ven ~n t~ Ctl8~ IIC~ tWo r~mngnetic chuck~ 18 and 19 are p~ovlded on~ tho mova~l~
table 13 on the oppot3:Lta ~ide~ of the back bar 15 rlgh~
nd~rnoath the ~orch 6 and the securem~nt clamp 1~ 18 pro~ded fo~ vortlc~l mov~ment on th~ oth~r electromaç1notlc chuck 1~
i~ po3slbl~3 to ccsrrec'c Any bendlnq ar warp~ ns~ of the nucc~eding s'c~el ~'crlp 2 and thus removo ~ny ~ep by energlzing ~che other ~lectromagn~tic chuck la.
In the abova example, a l~her beam weldlng torch 18 used ac ~he torch 6. As the la~er be~m weld~ng torch, the~ ~ave been d~velopod v~riou~ torches different with ~lferent powe~ sources.
Usually, cArbonlc acid ga~ la~er beAm weldlng ~o~che~3 Are u~ed, bu~ Al80 la~or ~eam ~aldlnq torche~ uging iocllne l~ar~ or th~
like a~ powor ~Yourco m~y~ be u~
Wher~ the torch 6 i~ construc~ed a~ 8 l~ler b~am weldlng tor~h for cut!clng and weld~ng s~ t~ip~ ~ith ~ thlckne~s o~
~bout 0.1 mm, th~re~ no noe~ of providlrlg th~ cut:~c.tng unlt 5 con~iotlng o the upper And lower blade~ 5a an~ Sb up~ream ~h~
torc~ 6. In other w~rd~, it i~ po~ible to con~ruct cuttet/w~lder a~ p~rt o~ a continuous processing lin~ a~ ehown ln Elg~. 7 and ~. ~n thi~ cutter/~lder, thn facillg e~ds of th~ two ~tael ~trlp~ l and 2 are c~ and fu3~0~ separat~d by the torch 6, and then the ~ut end gurf~cen 1~ and 2~ of the ~wo ~teel ~trlps 1 ~nd 2 are cau~ed ~o Abut each other and then weldad. rn th~
ca0e, the cutting by the ~u~ion ~ep~ra~ion and ~utt welding ar~

~2~32~

done by the torch 6. Therefore, whlle the construction ~ho~ in Fl~. 1 h~s ~hree ~llgn~ng unit~ 7, 8 ~nd 9, tha con~tructlon shown 1r~ F1ç1. 7 ~ onLy two allqn~ng unit~ 8 and 9. Al~o, tho movable ~ab1e 13 shown ln Flg. 7 1~ provlded with a fu0l~n ~epf~r~tion g~oove 46 in ~ddi tlon to th~ b~ck bar 15 . E'o~ th*
ra~t, the con~tructlon i~ the aam~ a~ that ~hown in Flg. 1.
In ~ig. 7, tho precedln~ ~teel str1p. 1 whlc~- ha~ been ~ed ~y ULs palr of , 1 . e., upper and lower, plnch ~oller~ provld~d on th~
up~trc~m slde and movable clamp 10 provlded on the dowh~tr~m rl~de, ia f~d up to the movable tabl~ 13 undernn~th the torch 6.
This movsb1~ table 13, llke the movsbl~ t2ble ~hown ln Figs.
~nd 2, ~ cap~ble of p~rnllel movement in ~ dlrectlon of th~
center 1~ne C-C in the continuou~ proce~s~n~ e (~ee Elg. 8) and r~volLItion by the ~e~volving table 20 ~bo~t tho re~olvlr,g ~ection 21. Thus, the s1de ec~e lb o the precedlng ~t~al ~tr~p a FiS~ mqde pa~allel to the center l~ne C-C by the al1gn1ng unlt 9, and ln thi~ ~t~te the trailin~ end i~ cut on the ~us10n separaSlon groove 46 by fu~ion ~eparation by the ~orch ~, Subae~uently, the precedlng ~teel strlp 1 i~ fed ~y predetermin~d dlatance by the down~tr~am side movable clamp 10.
The succeedlng ~tael ~tr~p 2 i8 ~180 Eed ~y the pAir of pinch r~ller~ 3 and 4 ilp to th~3 po~ tlon of the u~ion sep~rAt10n groove 46 of tha movable 13. Then, ~ in the ca~a of 'che precedin~ ateel a~rip 1 ~h9 s~de edge 2b ~3ee Fi~T. 8) i~ made p~rallel to the cent er llne C-C by ~he aligt~ihq unit ~, ~nd ~ho end i8 cut by ~ho ~rch 6. ~he cut end ~dge~ 1a and 2d 0~ the prec~d~ng and su~;;e~dlng ~teeL ~t~lp~3 1 qnd ~ are th~n cAu~ed to ~but ~ach o'che~ on th~ ~ac1t bat 15 ln the manner ~ descrlbed ~bove ~ncl then weldod by ~hc torch ~.
Mor~s spæci~lcally, th~ torch ~ offectE~ cutt1nq of 'che slclslg end~ of tl~s two a~el 13~crip~ 1 by fu~ion ~eparatlon ancl butt woldlng o~ the- cut ~urface~ 1A and ~a. ~he mo-~able t~bl~ 13 h~D~
the fu~lon ~pAra~ion groove 46 and bsck bar lS provided ln the mentloned order f~om ~he up3tre~m sid~, and 11ke tlle ar~n~ment o Flg. 1 elec~crohlagne~ic chuck~ 18 ~nd 1~ are provided on the oppoeite ~ld~a o tl~e back bar 15.

Thus as shown in Fig. 8, after the side edges lb and 2b of the preceding and succeeding steel strips 1 and 2 have been aliyned by the aligniny units 9 and 8, the ends of the steel stxips are cut by fusion separation on the fusion separation groove 46 by the torch 6. When butting the cut end surface, the trailing end o~ the preceding steel strip 1 is fed to a position on the ~ack bar 15, and the end edges la as the butting surface to be butted is brought into register with the torch running line 6a and then secured and magnetized by the electromagnetic chuck l9. In this state, the cut lo end surface 2a at the leading end of the succeeding steel strip 2 is caused to approach the end edge la. As a result, the end edge 2a is attracted so that it is reliably caused to butt the end edge la.
The aligning units 8 and 9, as shown in Fig. 8 consist of respective electromagnetic chucks 8a and 9a and reference blocks 8b and 9b. The electromagnetic chucks 8a and 9a and reference blocks 8b and 9b are movable by extension/contraction devices 8c and 9c in a direction perpendicular to the center line C-C of t.he continuous processing line. Thus, when the facing ends of the preceding and succeeding steel strips 1 and 2 are cut by fusion separation by the torch 6, the aligning units 9 and 8 are used, and when ef~ecting the abutting on the back bar 15 prior to the welding, the aligning units 9 and 8 are used respectively for the respective preceding and succeeding steel strips 1 and 2.
The cutting and welding as described above are suited for steel strips with thickness ranging from 0.05 to 1.0 mm, and particularly for silicon steel strips. The reason for this is that steel strips with thicknesses less than 0.05 mm are difficult to be - 24a -cut either by shearing, fusion separation, grinding, etc. while steel strips with thickness of 1.0 mm or above may be cut and welded in the prior art process, i.e., without need of using the present invention.
As has been descr;bed in the ~oregoing, the method and apparatus for cutting and welding steel strips acaording to the invention are very effective when joining together facing ends o~
preceding and succeeding steel strips for permitting a continuous rollinq or other processinq or when joini~
/

/

~ 2~ -ætael strlp~ or the like b~ weld~nq beore ~upplylng 'chem ~s ~
product ~o the cu~tom~r, pa~'clcularly for th~ purpose whlch welght a~ ~quired by tha customer. In these caso8, at the ti~ne o c~ ln~l cau3in~ the abuttlng ~nd weldinq steel 3~rlp~ th~
end~ o th~ ~teel ~trlp~ are ~ut ~r caused to ab-it wl~h hlgh ~ccur~cy by m~kln~ th~ c~nter line o the s~cel ~lp~ ~o be ln r~ tor or parallel wi~h thel centet l~ne of th~ pro(,eE~nln~ l~ne.
Thu~, lt i~ po~ible to obtai~ high qu~lity w~ldment.
F~lrt~er, s~nce even wlth steeL st~p~ of about 0.1 mm, for ~n~cance, h~h ~ccurAcy abuttln~ cAn be ~b~Alned, i~ i8 po~lbl~
to obtel~n hlqh p~rformn~ce laa~r beAm weldln~. Furthelr, when the high per~orm~nc~ la~er beAm w~ldln~ i~ applled, th~ ~oinad ~eel 8'C~ip c~n be wouhd lnto the form of a co~l withou~ any 1aw form~d eve~ lf the weld ls not removed. Thu~, the invention l~
vary efecti~ for the ~ining o sll1con ste~ rlp~ ~y weldl ng .

:

Claims (7)

1. In a continuous processing line, a method for butt-welding preceding and succeeding steel strips using a laser beam, in which a trailing end of said preceding strip and a leading end of said succeeding steel strip are cut to form a trailing end edge and a leading end edge, respectively, and then said trailing end edge and said leading end edge are butted against each other, thereby forming a butting line between said trailing end edge and said leading end edge and thereafter said preceding and succeeding steel strips are butt-welded by running a laser beam torch along a torch running line in conformity with said butting line, characterized in that said method comprises the steps of:
aligning one side edge of said preceding or succeeding steel strip to be parallel to a center line of said continuous processing line, by means of an aligning unit including an electromagnetic chuck, which electromagnetic chuck is moved to pull said preceding or succeeding steel strip until it is brought into contact with a reference block disposed parallel to said center line of said continuous processing line, said aligning unit being provided at a position adjoining at least one work table in said continuous line;
cutting said trailing end of said preceding steel strip to form said trailing end edge and cutting said leading end of said succeeding steel strip to form said leading end edge;
forming a butting line between said trailing end edge and said leading end edge comprising the steps of positioning said trailing end edge in register with said torch running line, magnetizing said trailing end edge by means of an electromagnetic - Page 1 of Claims -chuck provided beneath said laser beam torch so as to generate a magnetic attraction in said trailing end, directing said leading end edge downwardly and obliquely toward said trailing end edge having magnetic attraction therein, and approaching and butting said leading end edge against said trailing end edge; and butt-welding said trailing end edge and said leading end edge along said butting line by running said laser beam torch along said torch running line.

2. A method of butt-welding preceding and succeeding steel strips using a laser beam torch according to claim 1, wherein said preceding or succeeding steel strip has a thickness ranging from 0.05 to 1.0mm.

3. A method of butt-welding steel strips according to claim 1, wherein said preceding and succeeding steel strips are silicon steel strips.

4. An apparatus for cutting and welding steel strips, comprising:
a work table provided in a continuous processing line, in which facing ends of preceding and succeeding steel strips are cut and the cut end surfaces are caused to abut as butt surfaces and welded along the butt line formed by the abutting, said work table being capable of being moved along the center line of said continuous processing line and provided on part of the surface with a back bar;
a welding torch provided on said work table, capable of - Page 2 of Claims -being moved in a direction perpendicular to said center line and capable of being moved vertically toward and away from said back bar;
a revolving table for supporting said work table for revolution in part of said torch running line;
a cutting unit provided in said continuous processing line upstream of said work table, for cutting said facing ends of said two steel strips along a line perpendicular or substantially perpendicular to said center line;
a feeder provided in said continuous processing line upstream of said cutting unit for feeding said steel strips to the downstream side;
at least one electromagnetic chuck provided on said work table and upstream or downstream of said torch running line, on which side said torch running line is not contained, for attracting and holding the facing end of one of said two steel strips;
and raising means provided upstream of said work table, for raising the facing end of said other steel strip towards the cut end surface of said facing end of said one steel strip attracted to and held on said work table by said electromagnetic chuck such that said cut end surface is directed obliquely and downwardly.

5. An apparatus for cutting and welding steel strips according to claim 4, wherein at least two optical enlargement means are provided on said work table for optically enlarging the opposite ends of said abutting line, said optical enlargement means being capable of being reciprocated in a direction perpendicular to the center line of said continuous processing line.

- Page 3 of Claims -

6. An apparatus for cutting and welding steel strips, comprising:
a work table provided in a continuous processing line, in which facing ends of preceding and succeeding steel strips are cut and the cut end surfaces are caused to abut as butt surfaces and welded along the butt line formed by the abutting, said work table being capable of being moved along the center line of said continuous processing line and provided on part of the surface with a back bar;
a cutting/welding torch provided on said work table, capable of being moved in a direction perpendicular to said center line and capable of being moved vertically toward and away from said back bar, for cutting said facing ends of said two steel strips and effecting butt welding of said cut end surfaces of said steel strips;
a revolving table for supporting said work table for revolution in part of said torch running line;
a fusion separation groove provided on said work table adjacent to said back bar;
a feeder provided in said continuous processing line upstream of said cutting/welding torch for feeding said steel strips to the downstream side;
at least one electromagnetic chuck provided on said work table and upstream or downstream of said torch running line, on which side said torch running line is not contained, for attracting and holding the facing end of one of said two steel strips;
and raising means provided upstream of said work table, for raising - Page 4 of Claims -the facing end of said other steel strip towards the cut end surface of said facing end of said one steel strip attracted to and held on said work table by said electromagnetic chuck such that said cut end surface is directed obliquely and downwardly.

7. An apparatus for cutting and welding steel strips according to claim 6, wherein at least two optical enlargement means are provided on said work table for optically enlarging the opposite ends of said abutting line, said optical enlargement means being capable of being reciprocated in a direction perpendicular to the center line of said continuous processing line.

- Page 5 of Claims -