CA1128277A - Apparatus for manufacturing foundry cores - Google Patents

Abstract

Abstract of the Disclosure A feature of the present invention is that an apparatus for manufacturing foundry cores is provided with a device for fastening together halves of core boxes, located before a heating chamber, and with a device for unfastening the halves of the core boxes, arranged behind the heating chamber, each of the core boxes comprising two horizontal rods with conical elements placed in the bottom half thereof and cooperating with the above devices for fastening and unfastening the core boxes, and two vertical rods secured to the top half of the core boxes and having at their bottom ends slots and conical orifices cooperating with the conical elements of the hori-zontal rods. .
The above apparatus enables foundry cores tp be manufac-tured to stringent dimensional and geometric tolerances..

Description

~lZ~Z77 ~I~L;E O~ ~HE :I~V~ION
l~PP~IJS FOR lYE~U~ACTUR-~G ~ DR~ aORES
BAG~GROU~D 0~ IO~ ;
ield oî the ~i~e~tio~
~he ~ ention relates to îoun~ a~d more pa~ticularlg :~ to equipmerl~ for manu~actur~ fsu~drg cores in a heat0d ~ool ~ he i~ent~on can be emplo~ed at au~om~tiYe9 ~itary e~gixleer ~ g, electrical engineering, machine buildi ~ and other indu~tri~l production work~ inherent to which i9 a large-lot a~d ma98 charaoter o~ productio~
. 2. Description o~ the Prior Art In rec~nt years, methods ~or manufacturing ~oundry cores d~rectly in core boxe~ h~e found exte~ive ap~lication world practice, these being ~he ~o-called "hot-box" and "cola.
bo~'l pro~ess~.
~ he ~hot-bo~" process pro~des fo~ ~he manu~ac~ure of cores by blo~i~g a core~sand composed o~ sand, a binder and a ca~alyst into a heated core boxO The core sand ha~d~ns ~ -der the action o~ hsat ~nd oî the catalyst throu~h a rapid polymerization of the bi~der. ~ou~d~ mach~e buildi~g WOI'k8 m~ufacture a r~ge o~ multi-~ta*ion apparatus op~rating o~
the "hot-bo~:" principle. ~he apparatu~ clude~ a co~e-blow-~g mach~e, devices for disa~embli:~g core boxes arld del~-ver~g fi~ hed core-c~, a device for heati~g ~e core bo:æe~

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~28~77 a~d a transportation means for movi~g the core boxes Irom o~e sta~ion to another5 ~he apparatus operates as ~ollow~.
In the ~irst statio~, a hot box is pressed aga~n~t a ~a~d-blowIng plate and filled with ~and.,~he ~eco~d sba~ s intended ~or ~ape¢ti:~g ~d ~harlgi~s th~ ~o~;~e box~, 31exb, th~
~and hardens i~ several statlons, as the core bo~es are heated by either passing them through a heating chamber or e~ergizing heaters,built'I~to them. In the last station, the core boxes are opened ~nd, after a ~Inis~ed core is removed, blown with compr~ssed air.
~ he 7'cold-box'~ process pr~vides ~or the manu~acture o~
cores by blo~ a cold core bo~ with sa~d a~d a subseQuerlt hard~:~g thereof either throu~h bIo~ by a gaseous catalyst (~shland cold-~ox process) or the use oî a :highly reactive blinder with ~ greater amou~t o~ c~talyst (~ascold or Gisag cold-box process~. . -E~uipmellt for manufaGturing foundry core~ Qn the "coldbox" pr~ciple has become widely k~owrL.
- Overall, the equipment operati~g orL the ~Ihot-bo~c~ ~d "cold-box" pri~ciples t 1ivhile er~ ing ef~iciency, increasillg ~trength of` sarld and impro~i~ working conditions,, ~ails to pro~ide an eî~ective ve~tilatiorl o~ cores, ~ particular, such as cores for heating boilers and- radiators which are cast with metal on all sides a~d, ex~ept for two small core prints9 are out of contact ~vith a mouldO As sa:rld hardsns u~ifo:~mly througih-- ou~ the croæs section, ~re~s i~ coreæ a:re obtained and commu-nica~ed with the atimosphere b~ u~acturing cores o~ two . . . 3 .

. . ~ .,' ~ ~ : ' ' ~12~ 77 hal~es which are glued together5 ~he~e additio~al process operations substantiall~ complica~e the manu~acture o~ coresj raise labour requirement~, pre3udics geometric and d~me~slo~al accuracies OI ~ores~ hinder a complex automatlo~ of core m~u-facture~
~ here are k~lown a method a:nd an apparatu~ :eOr ca:rrgi~g the method into effect ~hich are ~ree o~ the above ~ortcoming (see ~RG pate:n~ llo~ 2~239,057, cl. B 22 C 9/10)~
~ he method consists in that a fluid a~d is pres~ed i~to a heated core box, the core box is ~ealed tight, then, a~ter a specified hol ~ ~ecessary to harden ~he s~nd, a ~Inished core i~ removea.
~ he method enables an~ core~ to be ~abricated m a single pi.ece, aæ a natu-ral canal or porosit~ is ~ormed ~n the middle o~ the core in the course of hardeni~ through which gase~
be e~ectiYel~ ~ented~ ~he apparatus is compo~ed o~ capacities and batchers of starti~g sand components, a mi~:er with a gate shutting off a dischar~se por~, a pressing c~linder with a ram~
a bat¢h~Lg chamber; a slid:lng damper wi~h a:cl expan~ible nozzle~
a lif~ing ta~le, and opera~eQ in the manner belo~0 Star~ing compo~ent~ of the ~and are ~ed In~o the miæer~
~tirred there~9 moving i~ the process toward the discharge por~9 where a fi~ished ~luid sand is fo3~med and tra~ erred in~o the b~tchi~g cham~er ha~:Lng the dampar i~ its bot~om par*. On~e the ba~ching chamber is filled with ~a~d~ the ga~e clo~e~ the dischargs port o~ the mixer, th~ damper slide~ to align the ~ozzle with the b~tGhi~g chamber, while ~he tabl~
lif~ and forces a heated core bo~ agai~st the noz~le. ~he xam . . ' ' i5 acted upon b~ a pres~ing c~linder to pack ~and into the core boxO O~ce this is completed, the core box is sealed to prevent sand from being ejected through the inlet ope~ing, A~ter a ¢er-tain time necessar~ ~or the ~oam to abate a~d the sand to lose mobility, the core box can be tra:~3ferred to a next ~ta~ionO
~he damper closes aga~n ~he bottom of the batc:h~ ohamber, the ram retur~s to initial position, and th~ ~ate opens the di~-c~arge port o~ the mixer. ~he c~cl~ is then repeated.
~ he pressure i~ the core box may rise u~der a certa~
set of cond~ions a~ld attain a ~alue sufîicie~ for o~ercomi~g ~he weigh~ o~ the top hal~ o~ the oore box. ~herefore, if a core box, after it has been packed and sealed, i~ held at the pressi~ position for a certai~ period of time, the ~op half htereof will be forced up, a~d ~ome sand will be ~pilled out along the part ~ plane, this una~oidably resulti~g in a de-rective core.
-Sa~d harden~ng requires much more time as compared to ~he "hot-bo~" and~the "cold-bo~" processes~ since hardenI~g takes place ma m}y through vaporization o~ moisture ~rom the ~luid 8ando ~ he prolonged holding of the core a~ter sand is pressed and the greater sand hardenI~g ~ime lead to a sub~tantiall~
lo~ger core manufacturin~ cycle and ~hu~ appreciabl~ lower both the e~icienc~ of the machine a~ compared to equipm~t operating on the l'hot-boæ" and the '~cold--bo2:'t princip~es and9 there~ore~ the advantages t:he machine may o~fsr i~ large-lot and mass production runs.
A material di~adva~age OI the known mach~rLe is tha~

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- ~lZ8277 lacks ~n de~ices permanently fa~tening together the halve~ o~
a core box ~rom the momen~ it is pac~ed to the mome~t it i3 opened. ~ iairly long holdin~ o~ a core box compressed between the table a~d the pressi~g mechanism, once the saad ha~ been packed, necessary to allow the sa~d pressure i~ ~he core box to ~all o~f ~u~icie~tly and ~o prevent the top o~ ~he ~ore box îrom being lifted once the core box is ~et îree, br~gs dow~ the e:E~iciency o~ the multi-statio~ machi~e, a~d in the ~inal a~alysi8 ~ provide~ no absolute guarantee that the top hal~ o~ the core box will ~ot be dislodged ~ertically by the residual pressure. A result o~ these molreme~ts may be a dis-to:F~ion o~ geometric dimenQions of cores a3ld a poorer quality thereof ~
S~ldll~ARY OF ~ ION
It is thereîore an object of l~e in~entio:~ to ~rovide an apparatus ~or manu~acturing ~oundry coreæ of high both di-m~sional ahd geometric accuracies.
~- Another object of the invention is to pro~ide an appara~
tus designea to e~sure a reliable ~astening of hal~es o~ the core box from the:mome~t o~ time preeedmg ~ressing o~ sand to the moment o~ time of disassembl~ ~nd to elIminate mo~ements o~ the top hal~ o~ ~he core box i~ the vertical plane~
Still a~other object o~ the inYen~ion is to increase the e~fici~ncy of the apparatus~
~ he abo~e and other ob~ects are attaIQed i~ an apparatus for manufacturing foun~ cores, compri~ing a support;i~ frame formed with two tiers~ the bottom tier car~yi~g a tranæpor~a--tion means and transfer tableæ, and the top one, sand prepa-ration and pressing mecha~isms, a pu~her with a ¢roQspiece, a heatIng chamber a~d mecha~ism~ ~or disassembling the core boxe~
and delivering a finished core, provided9 according to the i~
ve~tion, with a davioe ~or faste~I~g together halveg o~ the ¢ore boxes~ locabed before ~he hea~ing cham~er~ and a de~ce mounted behind the heating chamber and intended for unfasten ing the hal~es of the core boxes, each of the core boxe3 con-taining two horizo~tal rods with conical eleme~ts, placed in the bottom half o~ the core boxe~ and cooperating wi~h the : a~o~P devioe~ for fastenIng and nnfastenIng the core boxe~p and two vertical rods secured to the ~op half o~ the core bo~e~
a~d haviQg at their bottom ends slQts a~d conical ori~ices in-~e~ded for cooperating with the conical elements o~ the hori-zontal rods.
It is advisable to ha~e the de~ice for fastening the hal~es of the core boxes buil-t a~ horizontal pisto~ actuators hi4~ed ~o the pusher crosspiece, and the device ~br uD~aste~-i~g the halve~ o~the ~ore boxes, as a bracket with adju~table stops, mounted o~ ~he mecha~ism ~or di~assembling the core boxe~. .
AccordIng to the invention, the trans~r table lifts a hea~ed core bo:~: from ~he transportation mea~s and deli~er3 i~
to the pressing mechanism. ~he devices ~or ~aste~ g the hal~es of the core box ae-t upo~ the horizontal rods thereo~ i~ a manner ~hat the conical elements o~ t~e horizontal rod~ enter the co~ical orifices of the vertical rods. This results i~
their wedging so that both halYe~ of ~he core box are reliably , ?

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l~Z8Z77 ~astenedO ~his operatio~ eliminates the need ~or holding the hal~es o:f the c~re boxes together after pressin~ and substa~-tial~y reduces tha c~cle of operation o~ the apparatus. ~he dev~ce~ ~or fasteni~g the halves o~ the core box are hinged bo the pu~her cros~piece, this pre~enting aooideQbs should bhe mobile elements ~ail to return to initial po~itio~. ~he pr0s-8ing mechani~m packs sand prepared b~ the s~d prepara*io~
mechanism) in~o the core box, the core box is sealed a~d direct-1~ transferred by the pusher to the heating chamber which holds a ~umber of other core boxes. ~3 SOO~ as a first core box is pushed into the heating chamber, the last core box is dischar-ged Into the zone o~ action o~ a mechanism for delivering a finished core which pulls the core box o~er to the tran~fer tableO At the end of stroke, the horizontal rods o~ the core box meet the adaustable stops o~ the brackets mounted on ~he mechani~m for disassembling the core boxes, and the core boxe~
are returned to Initial position~ ~his gives rise to a wedging action which un~aste~ the halves of the core box. The co~ical elements o~ the horizo~ta~ rods are mo~ed out of the conical ori~ices of the vertical rods, and~ simulta~eously, the core box is unsealed. In this manner, the movemen~ of the core box upon the trans~er table is pu~ to good advantage, ~ul~hll~ng two additio~al operations, the ~ecessary le~gth o~ movement being determIned by the adjus~able stop~ pro~ided on the me cha~ism for disassembling the core boxes which opens the core box, whereas the vertical rods are disengaged ~rom the horl- -zon~al rods owing to the provisio~ o~ slots~

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: , , Once ~he core is remo~ed, the core box i~ re-assembled by the mechanism ~or disassembling the core boxe~ and lo~ered by the transfer table upo~ the tra~sportabion means which re-tur~es the core box to the pressin~ mechanism sba*io~
~ he multi-sta~io~ apparatus is built o~ two tiers~ 50 ag to minimize the width thereof a~d ~acilibate its ~ibing on existi~g ~loorspace. The apparatus roug~ly doubles the manu-Iacturing capacity and stabilizes the qualit~ of cores~, It should be emphasized ~hat a reliable fastenin~ o~ the ha~es of the core box ~rom the moment o~ time a ~luid sand is pac~ed therei~ to the mome~t o~ time ~he core box is disassembled substantially reduces the pollution OI the mechanism~ and makes the core manu~acturing proces~ clea~erO
BRIEF ~ESCRIP~IO~ OF ~E DRAWINGS
~ hese and ot~er objects and ~eatures of the invention become readil;y apparent from embodiment~ thereo~ ~hich will ~ow be described by wa~ of example with reference to the ac-comp~i~g drawi:llgs, irL which: -~ ?IG. 1 i~ a ge~eral view of the appa:ratus for manufae-tn~i~g- ~ou~dry cores9 FIG. 2 is a Yiew along arrow "A" on FIG.1;
FIG. 3 is a section throllgh III-III o~ FIGD2;
~ IG~I 4 i a section through ~-IV on :FIG.3;
FIG. 5 is a seetioll through V-V on ~IG~;
FIGo 6 ~s a ~iew along arrow l1B" ~ ~IG.5.
DESCRIP~IO~ OF ~HE PR;E~:RRED E~ODIlE~T
ap~pa~atus for manu~acturing ~oundry core~ (F:l:GS.1 .

~ ' , . ,:, ~ 2~7 through 6) ~ncludes a supporting frame 1 ~ormed wibh ~wo tiers, the bottom o~e carrying a transportation means 2 a~d trans~er tables ~ and 4, and the t~p one, a ~and preparation mechRni~m 5~ a pres~ing mechanism 6, a push~r 7 with a crosspiece 8 ha-ving pisto~ actuators 9 hinged thereto, a hea~In~ chamber 10 a mechanism 11 ~or disassembling core boxes wi~h bra~ke~ 12 and ad~ustable stops 13 and a mecha~ism 14 ~or delivering nished cores~
A core box 15 contains a top 16 and a bottom 17 hal~es locked one to another by pins 18 and buqhings 19~ ~he top hal~
16 carrie~ on diagonally opposite side~ ~ertical rods 20 with co~ical orifices 21 a~d slots 22 and built~in gates 23 ser~ing to seal the core box 15. ~hs bottom hal~ 17 incorporates ejec-tors 24 and bushings 25 intended as guides ~or horizon~al rod~
26 with conical eleme~ts 27. Sand is charged Into the core box through mlet ori~ices 28. The apparatus operates as follows.
~ he transfer table 4 lifts the core box ~5 f~om the trans~
por~ation means 2 ænd deliYers it to the pressing mecha~ism 6~
!l!he piston ac~uators 9 mo~e the hor370ntal rods 26 of the core bo~ 15 inæide the bushings 25 so as ~o ~n~age the co~ical ele me~ts 27 of the ho~izontal rods 26 into the collical orificeæ
21 of the vertical rods 20~ ~his produces a wedging effect which locks together the hal~es o~ the core box 15. ~he pres-sir~ mecha~ism 6 pac~s sand t~rough the i~le~ orifices 28, ~upplied by the sand preparation mech~nism 5. The gates 23 are mo~ed to close ~he orifiGes 2~9 a~d the core box is sealed and directed b.~ the pus~er 7 into the heat~ chamber 10 which accommodates se~eral o~her core boxes. ~s a ~re~h core box 1 .

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~%~277 charged in~o the heating chamber, a last core bo~ is dischar-ged therefrom into the zone of action of the mechanism 14 for deli~ering finished cores~ ~he mecha~ism 14 pulls the core box from the heati~g chamber 10 onto the trans~er table ~ whl~h i8 the~ in the top positio~ A~ the end of a sbroke~ bhe horizo~-tal rodc 26 meet the adjus~able stops 1~ o~ the mecha~ism 11 for disassembling core boxes and are guided b~ ~ushings 25 i~bo initial positio~. ~his produces a wedgi~g effect which opens the hal~es of the core box. ~he conical elements 27 o~ the horizo~tal rods 26 are mo~ed ou~ o~ the conical orifices 21 o~
the ~ertical rods 20. Simultaneously~ the core box is unsealed, and the gates 23 thereof return to lnitial position.
~ he mechanism 1i ~or disassembling core boxes opens the core bo2, and the vertical rods 20 disengage them~elves from the horizo~tal rods 26 owiDg to ~he slots 22~ Once a core is pushed out by the ejectors 24 and-removed ~rom the core box~
the co-re bo~ is re-assem~led and lowered by the trans~er table 3 upon the transporta~io~ means 2 which mo~es it toward the tran~fer table 40 ~noth~r cy~le of~operatio~ o~ the appara~uæ
8tarts when the trans~er table ~ moves upwards together wi~h the coxe box.
The apparatus according to th~ mve~ion pro~ides a ~
rou$hly double efficie~c~ as compared to exi~tIag coremAkI~g machines9 while retai~ing high both dimensio~al and geometric accuracîes of cores.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus for manufacturing foundry cores by pres-sing a fluid sand into heated core boxes, comprising:
- a two-tiered supporting frame; a transportation means and transfer tables mounted on the bottom tier of said sup-porting frame; a sand preparation and a pressing mechanism and a pusher with a crosspiece, mounted on the top tier of said supporting frame; a heating chamber hinged to said crosspiece;
a set of core boxes; a device for fastening halves of the core boxes, located before said heating chamber; a device for unfas-tening the halves of the core boxes, mounted behind said hea-ting chamber; each of said core boxes having two horizontal rods with conical elements, located in the bottom half of the core boxes and cooperating with said devices for fastening and unfastening the halves of the said core boxes, and two verti-cal rods mounted on the top half or said core boxes, having at the bottom ends thereof slots and conical orifices for cooperating with the conical elements of the horizontal rods;
a mechanism for disassembling core boxes, hinged to said cross-piece; a mechanism for delivering finished cores, placed on the top tier of said supporting frame.

2. An apparatus as claimed in claim 1, a wherein the de-vice for fastening the halves fo the core boxes is formed with horizontal actuators hinged to the crosspiece of the pusher, whereas the device for unfastening the halves of the core bo-xes is built as brackets with adjustable stops, mounted on the mechanism for disassembling the core boxes.