CA1069286A - Device for removing internal circular flash - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The invention relates to a device for avoiding inter-nal circular flash during resistance butt-welding of pipes. The device includes a tool head with a body, which head carries a holder with a cutting tool. An appliance brings the tool head to the flash-removing zone, and the appliance is provided with a cantilevered rod whose free end is connected to the tool head.
A radial feed mechanism of the holder is accommodated in a hous-ing of its own and includes a drive for rotating the mechanism.
The radial feed mechanism of the holder is made in the form of a hydraulic cylinder whose rod carries a rigidly secured holder connected with the housing of the radial feed mechanism by springs which ensure the cutting force of the cutting tool and bear against the housing of the radial feed mechanism of the hol-der at one end while at the other end they bear against the hol-der rotated by a drive installed on the tool head body. The shaft of the drive is connected rigidly with the housing of the radial feed mechanism which carries a slide valve whose rod in-teracts with the profiled surface of a master form, and the hol-der is provided with rollers for tracing the internal surface of the welded pipes.

Description

lO~9~h~

DEVICE FOR REMOVING IN~$RN~L CIRCU~AR ~ASH

~ e pre~ent invention relates to devices ~or ma¢hining hollow bodies of revolution and more particularly it relates to de~ices for removing internal cixcular fla~h remaining aRter resistance butt-weldi~ of pipeqO
Known in the previous art are device~ ~or ~emo~in~ intern-al circular ~lash comprisi~ a cantil~vered rod carr~ing sprin~
loaded strikers. Under the e~fect of centri~ugal ~orces t~e strikers rotated by an electric motor strike the cir~ular weld whose tamperature is ~00- 1100C, knock off the scale and smooth out the ~lash.
Another known de~ice ~or removin~ intsrnal circular fla3h during resistance butt-welding o~ pipes comprlses a tool head with a bod~ carrying a ~older with a cutting tool, a r-~adial ~eed mechanism a~commodated i~ a housi~g of its own and a~ta-ry drive o~ said mechanism, also an appliance for bringing t~e tool head to the ~lash r~moving zo~e. Said applianoe oarrie~ a oa~til~ered rod ~hos& free end is connected with tho ~ool he~d~
.
A disadva~aga o~ the above-men~iorled ~la~ remoYer~ re ~ ~
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: ~ sides in that th~ re ~ iability oi ~la3h remo~al depa~ds o~ the flash temperature.
I~ the above-mentio~ed ~la~h removers have not b9en used .
in due time ar~d t~e temperature o~ ~lash has dropped below ~h~
preset l~vel, i~ happen~ o~ten that the ~lash ca~not be removed ., .

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Another disadvantage o~ the above-mentioned ~lash removers lies in their failure to e~sure u~i~orm removal o~ flash around the pipe perimeter i~ the pipe~ are out-of-round and the welded joint is displaced.
Other disadvantages o~ the above-mentio~ed ~lash rsmover~
include also the no~uni~orm loading o~ the drive caused b~ the uniform ~eed oi ~e ~ool irrespective o~ bh~ ~lash cro~ ~ection whioh grows towards its bas~.
ID ~he main object o~ the present invention is to provide a devi~o ~or removing internal circul~r ~lash i~ resi~tance butt-welding of pipes which would en~ure removal o~ ~lash re~ardless of its temperature.
~ nother object o~ the prese~t i~v~ntlo~ is to provide a devi~e ~or rcmoving internal oircular ~la~h which would ensure uniform removal of i~ter~al ciroular ~la~h regardles~ o~ the out--o~-roundness and displac3ments in the weld~d joint.
~ d still anot~er object o~ the inve~tio~ is to provide a device for rsmoving internal circular ~lash which would ~n~ure variable radial ~eed within a revolutio~ of the cutti~g tool in accordanoo wit~ the g~ometry o~ ~lash.
~ hese and other ob~ects are ac~omplished b~ providi~g a de-.
vice for removi~g i~er~al ¢ircular flash durin~ resistance bu~t-, -welding o~ pipas comprising a tool head with a body carrying a holder with a cut~ing tool, a me~hani~m ~or radial ~eed o~ the

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holder in a hou~ing of i-t~ own, a rotaI~ drive of said mecharlism, and an appliance ~or bringi~g the tool head to the fla~h remov-ing zone, said appliance bei~g provided with a cantilevered rod whose ~ree end is con~ecbed with the -tool head wherein, accord-ing to the invention, the radial feed mecha~ism of the holder is made in the form o~ a ~ydraulic cylinder whose rod carries a ri-gidly ~ecured holder connected with -the housing o~ i-ts radial ~eed mechanism by springs ensuring the ¢utting ~orce oi the cutt-ing tool ~aid spring~ bearing at one end against the housing o~
o the radial feed mechanism while at the other e~d they bsar again~t the holder which is rotated by a drive mounted o~ the tool head body, the shaft o~ said drive being connected ri~idly with the ~ousing o~ the radial ~eed mechanism of the hold~r, said housing carr~i~g a slide valve whose rod interacts with the pro~iled ~ur-face o~ a master form ri~idly ~ixed on the bool ~ead bod~, th~
holder being also provided with rollers ~or tracing the internal sur~ace o~ the welded pipe.
~ he device en~ures u~i~ormity of ~lash removal around bhe perimeter o~ the butt joint even if the ~edl~d pipes are out-o~--rou~d. Besides, as th~ ~lash is being gradually removed3 bhe device reducs~ the depth o~ cut proportionall~ bo the changin~ :
shape o~ ~lash and thus rebai~s the cutbing force practioally . . . .
constant.
It is eæpedisnt t~at the tool head should have a~ alig~-ing ~pplia~ce comprisi~g pushers in~talled radially in the ~ool '~
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head body and carrying ~hoes which are set in motio~ by hydrau-lic cylinders mounted on the tool head bod~.
The usa o~ the aligning appliance ensures the minimum ra-Quired travel o~ the cutting to~1. Besides, b~ bringing the cutt-ing tool a~ ~lose as possible -to the ~lash removing zone it is possible to ~horten the cantilever arm a~d thus to increa~e the stiP~ness o~ the de~ice in the course o~ cutting9 It is likewise e~pedient that the devica for removing inter-nal circular Plas~ during resista~ce Outt-weldi~ o~ pipes should have a~ appliance for taking the ~lash away rrom the zone o~ its removal, said applia~¢e being made in the ~orm o~ electromag~eti¢
coils with steel core~, secured in the lower part o~ the tool head body~
The appliance ~or taking the ~lash away ~rom the zone of its removal makes it possible to produc~ a rein~orcement o~ a uni~orm height of the internal sux~ace o~ pipes by removing the cut-o~f ~lash ~alling in the lower part o~ the welded pipe ~rom under the rollers which trace the inter~al ~urfaca o~ the welded pipes.
Now the invention will be described in detail by w ~ o~
e~ample with re~era~c~ to the accompan~ing drawin~s in which:
~ ig. 1 is a ge~eral view o~ th~ de~ice ~or ramoYi~g in-ternal oirGul~r ~lash duri~g resistance butt-weldl~ accordi~g to the inv~ntion;
Fig. 2 i 5 a seotion t~ken along line II~ Fig. l;
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, . ., ~ . - - , -:, ' ; . - -: ' . : : . ~ ' - : - . '' ' ' Figa 3 i8 a section taken alon~ line III - III in Fig, 2;
~ ig. ~ is a hgdraulic control diagram of -the holder radial ~eed mechanism.
The device for removing illternal circular ~lash durin~
resistance butt-weldillg o~ pipes accordi~l~; to the invsntion com-prises a tool head 1 (Fig. l) with a body 2 (~ig~ 2) carrying holders 3 (Fig. 3~ he holders 3 clamp cu~ting tooLs, e.g. cutt-ers 4 a~d ha~e rollers 6 ~or tracing the i~ternal su~ace o~ the welded pipe~ 5~ The device according to the invention also com-prises a mechanism ~or radial ~aed o~ the holders ~ i~ the ~orm o~ bydraulic cylinder~ 7 whose rods ¢arry the rigidl~ fi~ed hold-ers 3. ~he housing 9 o~ said radial ~eea mechanism is provided with a ~lide valve 10. ~he hydraulic cylinders 7 controlled via the slide valve 10 are kinematicall~ linked with the holders 3 b~
means o~ ~pri~gs ll which bear against the housin~ 9 o~ the radi~
al ~eed mecha~ism at one end a~d against the holders 3 at the other.
~ he hou ing 9 o~ said mechanism is rigidly sonnectea with the shaft 12 which is rotated i~ rolling contact beari~s 13 by a drive 14. ~ha drive 14 may be b~draulic~ pneumatic or electrio .
~ he drive 14 i9 conne~ted with the sha~t 12 b~ a coupling ~ a~te~ed rigidly to th~ tool head body 2 is a master ~orm 16~ during ro~atio~ o~ the holder~ ~ said ma5ter ~orm int~rac~s _5_ - - ~ ..... .

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-with the rod 17 o~ the slide valve 10~
The le~gth and pro~ile o~ t~e master ~orm 16 are selected in accordance with the radial ~eed per revolutio~ of the holder with the tool 4, '~he device incorporates an appliance ~or taking the flash away ~rom the zone of its removal~ made i~ the form o~ electro-mag~et~ 18 9ecured in the lower part o~ the tool head body 2.
The electroma~nets 18 ¢onsist of steel cores 19 carryi~g electro-magnetic coil~ 20.
~ he shaft 12 o~ the ro-tary drive 1~ carries a scraper 21 and ~he body 2 has a ~lange 22 accommodati~ a seal 23. The seal 23 i9 communication t~rough a discharge pipe 24 with the under-pi~ton ohambers o~ the hydraulic cylinders 7 whersa~ their above-piston chambers are connected to ~ree di~charge through a discharge pipe 25.
~ he ~ool head 1 i~corporates an alig~ing~ appliance 26 in-stalled on its body 2, and radially-mounted pushera 27 with shoes 28. The pushers 27 wit~ the shoes 28 are re~iprocated b~ the ~y-draulic cylinders 29 mounted on the body 2 o~ the tool head 1~
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,o q?he tool head 1 is ca~tilevered ~o the rod 30 ~ . 1) pro-vided with an applia~c~ or bringin~ the tool head to the ~lasb removing æo~e.
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q!o prevent the radial ~eed mechanism irom stopping in a position when the rod 17 of the slide valve 10 is sunk by t~e master form 16, there is a limit swit5:~h 32 installed o~ the ~lange .

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of the tool head 1~ a~d a pressure strap 33 fa~tened to the hou~-ing 9 of the radial feed mechanism.
The limit switch 32 co~trols the slide val~e ~4 (I~'ig. 4) which, in -tur~, controls the travel of the holders 3 wit~ the cut-ting -tool 4.
~ he device ~or removi~g i~ternal ciroular ~lash during re-sistance butt-welding o~ pipes operate~ a~ follows.
After the pipe~ 5 have be~s~ ~lded, the cu-tters 4 axe bro- -ught by the appliance 31 to the flash-remeving zo~e, aligning the a~is o~ the cutter 4 ~ith the welded joint.
~ he working ~luid is fed under pressure into the above~pi- :~
ston ohambers of the hydraulic cyli~ders 29 and the pipe 5 i~
clamped~ .
~ he working ~luid into the piston chambers of the 4ydraulic c~linder~ 7 is fed from the hydraulic s~stem (not show~ in the ~igure) through the slide ~alv~ 34. Then the drive 14 o~ the holdsrs 3 with the cu~ters 4 is tur~ed on. During each reYolution o~ ~he GUtter~ the master ~orm 16 presses the rod 17 o~ the ~lide ~alve 10 with its profiled sur~aee and puts the under-piston cham~
bers of the hydraulio cylinder 7 in communication. with di~charga 25~ Mea~w~ile, the holder3 3 with t~e out~ers 4 will be mo~ed radially ~ the springs 11 t~rough a dista~ce determitled by the ~olume o~ tha iluia ~lowing ~rom the under-piSton ohambers o:
the b;ydrauli~ c;yl1rldèrs 7 i~to the discharga pipeline 25.
~ e cuWi~g process 9tarts as soon as the ~utters 4 come ir ooutaGt wit~kh~3 :elash.
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~ he farther the holders ~ with cu.tter~ 4 move ~rom the cent-re o~ the pipe 5, the smaller b3comes the force of the ~prings 11 andg consequently9 the smaller the radial ~eed of each cutt~
er 4 per revolutio~, the le~g~h o~ the master ~orm 16 and the rotation speed during cutting being constant.
~ hus, bhe ~eed per re~olution o~ the holders 3 with cutt-ers 4 i~ the course o~ cutti~g decreases as the ¢utters 4 appro-ach the internal sur~aces o* the pipes 5 and, since the width o~ the ~lash correspo~dingly increases i~ height, t~e cutting ~orce remai~s practically consta~t.
~ o keep the cutter ~rom biting into the body o~ t~e pipe 5 a~d to ens~re the desired height o~ the weld rein~orce-ment, the lips o~ the cutters 4 are set ~earer to the rotatio~
axis of the holders 3 than the ge~aratrice~ o~ the tracing roll-ers 6.
~ he misalignme~t of the rotatio~ axis o~ the holdor~ 3 with the a~is o~ the pipes 5 as well as the out;o~-roundn~ss of the pipes 5 are made up for Ln the course o~ ~lash cutti~g b~ springs 11. Simulta~eously wlth the starti~g of t~e dri~e 14, the coils 20 of the alectromagnets 18 are energized a~d their oores 19 at- :
tract the cut-off fla~h, ~his method o~ taking away the ~la~
~rom the æo~e o~ its removal provides ~or ~ormal worki~g co~di-, tions of the tool 4.
~ s soon as the ~lash is completely cut o~f, the drive 14is turned o~ he under-pisbon chambers oi the ~ydrRuliG Gylinders.

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7 are put in communiGa-tion with the di~charKe pipeline 24 by the slide valve ~4. As a result~ the ho;Lders 3 with the cu-tter~
4 move radially -towards the centre, to the initial position.
~he pipes 5 are released from the aligni~g appliance. ~ter the pipes 5 have been released, the device is shi~ted ~or remov-ing ~lash ~ro~ the ne~t joint of the welded pipes. The scraper 21 ~ove~ inside the pipe~ and pu~h~3s of~ the ~las~ -that has falle~
on the bottom o~ the pipe a~ter deenergi ing o~ the electro~agne-tic coils 17.

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Claims (3)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. A device for removing internal circular flash during resistance butt-welding of pipes comprising a tool head with a body, said head carrying a holder with a cutting tool, an ap-pliance for bringing the tool head to the flash-removing zone, said appliance being provided with a cantilevered rod whose free end is connected with the tool head, a radial feed mechanism of the holder accommodated in a housing of its own and a drive for rotating said mechanism, the radial feed mechanism of the holder being made in the form of a hydraulic cylinder whose rod carries a rigidly secured holder connected with the housing of the ra-dial feed mechanism by springs which ensure the cutting force of the cutting tool and bear against the housing of the radial feed mechanism of the holder at one end while at the other end they bear against the holder rotated by a drive installed on the tool head body, the shaft of said drive being connected rigidly with the housing of the radial feed mechanism which carries a slide valve whose rod interacts with the profiled surface of a master form, the holder being provided with rollers for tracing the in-ternal surface of the welded pipes.

2. A device according to Claim 1 wherein the tool head in-corporates an aligning appliance comprising pushers with shoes arranged radially in the tool head body and actuated by the hy-draulic cylinders mounted on the tool head body.

3. A device according to claim 1, incorporating an appliance for taking the flash away from the zone of its removal, made in the form of electromagnetic coils with steel cores se-cured in the lower part of the tool head body.