SE181101C1

SE181101C1 -

Info

Publication number: SE181101C1
Authority: SE
Publication date: 1962-01-01

Description

Uppfinnare: W W Urmetz Prioritet begord frcin den 2 maj 1956 (USA) Denna uppfinning avser forbattringar vid overtackningar, som anvandas vid stelnande metallgjutstycken, sarskilt got och sjunkgjut. Inventor: W W Urmetz Priority Required February 2, 1956 (USA) This invention relates to overlayment overruns used in solidifying metal castings, especially cast iron and sink casting.

Det är allmant brukligt vid framstallningen av stalgot att placera en sjunkbox pa vane gjutform, att halla smalt sta.l i formen och till en bestamd hojd i boxen och att utstro nagot lost kornformigt eller pulverformigt material pa den blottade ytan av det smalta gotet for att forminska varmeforluster fran denna yta. Dessa material kunna. vara antingen isolerande eller exotermiska till beskaffenheten eller en kombination av bada. It is generally customary in the manufacture of steel casts to place a sink box in a conventional mold, to keep a narrow steel in the mold and to a certain height in the box, and to spread some loose granular or powdery material on the exposed surface of the narrow casing to reduce heat losses from this surface. These materials can. be either insulating or exothermic in nature or a combination of baths.

Sjunkboxen verkar som en kalla av smalt metall for det stelnande gotet, i vilket en minskning i volym eller krympning sker vid stelning av det smalta stalet. En sjunkbox liar begransad effektivitet, sá att efter slutlig stelning av gOtet finnes det restmetall i boxen, vilken icke kan goras till saljbar produkt. The sink box acts as a cold of cold metal for the solidifying cast, in which a decrease in volume or shrinkage occurs upon solidification of the narrow steel. A sink box has a limited efficiency, so that after final solidification of the cast, there is residual metal in the box, which cannot be turned into a salable product.

Om ingen overtachning placerades pa. den blottade smalta ytan i sjunkboxen, skulle en storre mangd metall stelna och bli kvar i sjunkboxen. Darfor anbringas en overtackfling pa den smalta ytan for att bibehalla stalet small, och ju effektivare Overtackningen blir, desto mindre stal behover hallas i sjunkboxen fOr att sorja for ett felfritt gOt och maximum av produkt. If no takeover was placed on. the exposed narrow surface of the sink box, a large amount of metal would solidify and remain in the sink box. Therefore, a roofing flap is applied to the narrow surface to keep the steel small, and the more effective the roofing becomes, the less steel needs to be kept in the sink box to ensure a flawless quality and maximum of product.

Ett andamal med foreliggande uppfinning ar att frambringa en effektivare overtackning an som anvandes for narvarande och darigenom Ora en storre procent av gotvikten till felfri produkt. An object of the present invention is to provide a more efficient overlay than is used at present and thereby a greater percentage of the good weight to a faultless product.

Uppfinningen bestar i ett varmekvarhallande lock for anyandning i den oppna Sync anden av en gjutform eller sjunkbox, i vilken small metall gjutes, och omfattande ett bottenlager av exotermiskt material, en obrannbar skiljeplatta ovanfor bottenlagret och ett lager av isolerande material ovanfor skiljeplattan, kannetecknat darav, att forutbestamda tjocklekar av det exotermiska materialet och av det isolerande materialet Oro anordnade nedanfor resp. ovanfor skiljeplattan inuti en varmeforstorbar behallare, varvid nemnda lager och skiljeplattan Oro skilda fran varandra. The invention consists in a heat retaining lid for inhalation in the open Sync spirit of a mold or sink box, in which small metal is cast, and comprising a bottom layer of exothermic material, a non-combustible separator plate above the bottom layer and a layer of insulating material above the separator plate, that predetermined thicknesses of the exothermic material and of the insulating material Oro arranged below resp. above the separating plate inside a heat-expandable container, the said layer and the separating plate Oro being separated from each other.

Genom anvandning av det varmekvarhallande locket enligt uppfinningen vinnas betydande fordelar vid stalgOtframstallningen. I stallet Mr att som hittills losa, korniga eller pulverformiga material kastas pa gotet av arbetare, som kanske sakna nodig erfarenhet och vana, sa att oregelbundna mangder kunna pafOras gotet i en heta med alfoljande for-lust av produkt, palagges det nya locket pa gotet i gjutformen eller sjunkboxen, varigenom nar den nomnda behallaren faller solider, en bestamd mangd exotermisk massa successivt utbredes pa den smalta metallen och Over det exotermiska lagret bildas en delare eller mernbran, vilken joke faller ihop, da den smalta metallnivan sjunker under sammandragningen av det stelnande gotet, varvid namnda membran understodjer ett lager av hogisolerande men joke sjalvbarande material. By using the heat retaining lid according to the invention, significant advantages are gained in the steel production. Instead of, as hitherto loose, grainy or powdered materials being thrown on the goat by workers, who may lack the necessary experience and habit, so that irregular quantities can be poured on the goat in a heat with all-encompassing loss of product, the new lid is put on the goat in the mold or sink box, whereby when the said container falls solidly, a certain amount of exothermic mass gradually spreads on the narrow metal and Over the exothermic layer a divider or mernbran is formed, which joke collapses, as the narrow metal level sinks during the contraction of the solidifying the gotet, said membrane supporting a layer of highly insulating but joke self-supporting material.

Det hanvisas till bifogade ritning. Fig. 1 visar i vertikalsektion en del av en kokill med en sjunkbox anordnad i forbindelse med den ovre anden av kokillen, varvid i formen och sjunkboxen har ihallts small metall, och ett lock enligt foreliggande uppfinning understott ovanpa gotet. Fig. 2 Or en. vertikalsektion lik fig. 1 och visande laget av de olika komponenterna av locket, efter det att lockets behallare liar forbrukats. Fig. 3 Or en perspektivbild visande en form, som locket skall antaga. Fig. 4 Or en sektion efter lin- 2— — jen 4 4 i fig. 3. Fig. 5 ãr en vertikalsektion lik fig. 1 och 2 visande laget av elementen av locket i nagot ogonblick under stelning av gotet. It is referred to the accompanying drawing. Fig. 1 shows in vertical section a part of a mold with a sink box arranged in connection with the upper spirit of the mold, wherein in the mold and the sink box small metal has been held, and a lid according to the present invention is supported on top of the gutter. Fig. 2 Or en. vertical section similar to Fig. 1 and showing the layer of the various components of the lid, after the container of the lid has been consumed. Fig. 3 Or a perspective view showing a shape which the lid is to assume. Fig. 4 is a section along the line 2-4 in Fig. 3. Fig. 5 is a vertical section similar to Figs. 1 and 2 showing the layer of the elements of the lid at some moment during solidification of the casing.

Locket i och for sig omfattar en behallare 1 gjord av ett stelt eller sjalvbarande brannbart material med botten- och sidovaggar la och lb samt en klafftillslutning, vilken a" for-mad i tva delar 2 och 2a, varvid dessa delar foretradesvis aro forenade med andvaggen av behallaren och fallas Over i det lage, som visas i fig. 3, nth- innehallet i boxen har placerats dari. The lid itself comprises a container 1 made of a rigid or self-supporting combustible material with bottom and side walls 1a and 1b and a flap closure, which is formed in two parts 2 and 2a, these parts preferably being joined to the cradle. of the container and is dropped into the layer shown in Fig. 3, the contents of the box have been placed therein.

Inuti den undre delen av behallaren 1 anbringas en onskad mangd av exoterraisk massa 3. Lampliga exotermiska massor aro valkanda, och ingen sarskild besk-rivning darav behover givas. Over den exotermiska massan 3 anbringas en stel mellanvagg eller delare 10, vilken antager formen av en platta och kan vara av tunn stalplat eller kan vara av keramiskt material eller vilken annan sammansattning som heist, som icke faller ihop vid den temperatur, for vilken plattan kommer att utsattas i anvandning. Delaren eller plattan 10 anligger mot sidorna av behallaren 1, vilken kan vara forsedd med en hylla inforlivad i sidovaggarna lb for att upptaga delaren 10. Inside the lower part of the container 1 a desired amount of exoteric mass 3 is applied. Suitable exothermic masses are selected, and no special description thereof needs to be given. A rigid intermediate wall or divider 10 is applied over the exothermic mass 3, which assumes the shape of a plate and may be of thin steel plate or may be of ceramic material or any other composition which does not collapse at the temperature for which the plate comes to be exposed to use. The divider or plate 10 abuts against the sides of the container 1, which may be provided with a shelf incorporated in the side cradles 1b to receive the divider 10.

Ovanfor delaren 10 finnes en kropp av isolerande material 5 jamnt fordelad over densamma. Det isolerande materialet 5 kan vara asbestfiber, asbestplatta, sil-o-cel, isolerande chamotte eller vilket lampligt material som heist for den avsedda anvandningen. Nr den onskade mangden exotermiskt material 3 har placerats i behallaren och delaren 10 place-rats Over (let exotermiska materialet samt de isolerande materialen placerats ovanpii plat-tan, stangas och forseglas behallarens 1 klaffar 2 och 2a frambringande ett paket, vilket kan forsandas med ett minimum av fororening eller sonderslagning och vilket fir latt att hantera, nar locket placeras pa den smalta metallytan. Above the divider 10 is a body of insulating material 5 evenly distributed over it. The insulating material 5 may be asbestos fiber, asbestos board, sil-o-cell, insulating chamotte or any suitable material for the intended use. When the desired amount of exothermic material 3 has been placed in the container and the divider 10 has been placed over the exothermic material and the insulating materials have been placed on top of the plate, the flaps 2 and 2a of the container 1 are barred and sealed to produce a package which can be sanded with a minimum of contamination or decomposition and which is easy to handle when the lid is placed on the narrow metal surface.

Genom sit man presser mat endera av eller bada de perforerade flikarna 6 eller 6a kan man trada ett langt handtag Over klaffarna 2 eller 2a och racka Over locket samt slappa ned det i en sjunkbox, vilken her fyllts med smalt stal. Alternativt kunna flikarna befinna sig pa lockets sidovaggar, sasom den vid 6' visade. By pressing food either off or bathing the perforated flaps 6 or 6a, you can thread a long handle over the flaps 2 or 2a and rack over the lid and relax it in a sink box, which here is filled with narrow steel. Alternatively, the flaps can be located on the side walls of the lid, as shown at 6 '.

Vid beroring med det smalta stalet kommer den brannbara behallaren 1 att ogonblickligen brinna och frigora det exotermiska materialet 3 pa den smalta metallytan. Detta material antandes och reagerar for att generera varme, som forlanger flytbarheten av det smalta stalet i sjunkboxen. Delaren 10 blir till en membran, vars kanter vila pa kransen av stelnad metall, som frusit mot de inre ytorna av sjunkboxen, sasom visas i fig. 2. Delaren 10 uppvarmes till en mycket hog temperatur och skulle utstrala mycket varme till atmosfaren ovanfor locket, om icke ett lager av isolerande material 5 vilade pa den- samma. Da smalt stal i formen stelnar, sker en volymsammandragning eller krympning, smolt stal matas nedat fran sjunkboxen for att uppvaga denna krympning, och den smalta nivan i sjunkboxen faller. Upon contact with the narrow steel, the combustible container 1 will instantly burn and release the exothermic material 3 on the narrow metal surface. This material ignites and reacts to generate heat, which requires the flowability of the narrow steel in the sink box. The divider 10 becomes a membrane, the edges of which rest on the ring of solidified metal, which freezes against the inner surfaces of the sink box, as shown in Fig. 2. The divider 10 is heated to a very high temperature and would radiate a lot of heat to the atmosphere above the lid. unless a layer of insulating material 5 rested on the same. As narrow steel in the mold solidifies, a volume contraction or shrinkage occurs, molten steel is fed down from the sink box to compensate for this shrinkage, and the narrow level in the sink box falls.

Med de vanliga korniga eller pulverformiga tackmaterialen enligt hittillsvarande teknik skulle sankningen av den smalta nivan i sjunkboxen vara alfaljd av nedatgang av tackmaterialet. Delta tillstand skulle blotta de frusna sidovaggarna av det formande sjunkhuvudet, si att det utstralade varme till atmosfaren och tillat konvektionsstrommar av kall luft att inkomma i halrummet och bortfora mere varme. With the usual granular or powdered filling materials according to the prior art, the lowering of the narrow level in the sink box would be accompanied by a descent of the filling material. Delta condition would expose the frozen sidewalls of the forming sinker head, say that it radiated heat to the atmosphere and allowed convection drums of cold air to enter the cavity and dissipate more heat.

Vid denna uppfinning ride reaktionsprodukterna av den exotermiska massan pa den sjunkande nivan av den smalta metallen som en mellanisolering mellan den smalta metallen och delaren 10. Den senare plus dess iso- lerande lager 5 forhindra konvektionsstrommar och forminska stralningsforluster frau den smalta metallmassan och det stelnade skalet 7a sasom visas i fig. 5. In this invention, the reaction products of the exothermic mass ride on the falling level of the molten metal as an intermediate insulation between the molten metal and the divider 10. The latter plus its insulating layer 5 prevent convection currents and diminish radiation losses from the molten metal mass and the solidified shell. 7a as shown in Fig. 5.

Anvandningen av det har beskrivna isolerande locket fOrminskar varmeforluster ge- nom den oppna Linden av sjunkboxen och forminskar den mangd smalt stal, som behoves i sjunkboxen for att frambringa ett felfritt got. The use of the insulating lid described describes Reduces heat loss through the open Linden of the sink box and reduces the amount of narrow steel needed in the sink box to produce a flawless cast.

Vanligen ar den mangd smalt stal, som halles i en sjunkbox, 15-20 % av den sam- manlagda mangd, som halles i bade form och sjunkbox. Den mangd small stal, som utmatats fran sjunkboxen till del stelnade gotet, ar 3-% av den sammanlagda metallmangd, som hallts i formen och sjunkboxen. Detta behOves alltid for att frambringa felfritt gOt och maximimangd felfri produkt valsad av gotet. Usually the amount of narrow steel, which is kept in a sink box, is 15-20% of the total amount, which is kept in both form and sink box. The amount of small steel discharged from the sink box is partly solidified, is 3% of the total amount of metal held in the mold and the sink box. This is always needed to produce flawless goods and the maximum amount of faultless products rolled by the goods.

Skillnaden mellan namnda 15-20 % och 3-5 % ar den mangd small stal, som gar till spillo genom sjunkboxens ineffektivitet. Denna ineffektivitet är inneboende och tillskrives varmekapaciteten och ledningsfOrmagan hos sjunkboxens massa och varmeforlust genom den. ovre Linden av sjunkboxen. The difference between the said 15-20% and 3-5% is the amount of small steel, which is wasted due to the inefficiency of the sink box. This inefficiency is inherent and is attributed to the heat capacity and conductivity of the sink box mass and heat loss through it. upper Linden of the sink box.

For en fast sjunkboxkonstruktion enbart kan varmeforlusten genom den ovre anden fOrminskas, och det liar beskrivna isolerande locket forminskar dessa forluster markbart, sasom visas av resultat erhallna genom stalverksprov. For a fixed sink box construction alone, the heat loss through the upper spirit can be reduced, and the insulating lid described below significantly reduces these losses, as shown by results obtained by steelwork tests.

En viss sjunkbox- och gjutforin-kombina- lionmed exotermisk overtackning fram- stallde ett 3800 kg got, av vilket 3230 kg smalt sta.l voro i formen och 571 kg i sjunkboxen. Delta senare var 15 % av hela gOtet. A certain sink-box and cast-iron combination with exothermic roofing produced a 3800 kg cast, of which 3230 kg narrow steel were in the mold and 571 kg in the sink box. Delta later was 15% of the entire gOtet.

Samma kombination av sjunkbox och form fordrande 3230 kg smalt stal i formen fordrade endast 481 kg smalt stal i sjunkboxen (13 % av hela gotet), nar den tacktes med det — —3 har beskrivna isolerande locket. En besparing av 91 kg stal per got gjordes. For denna sr- skilda praktik framstallde den oppna hardugnen 41 got med det konventionella locket och 42 got med locket enligt denna uppfinning. The same combination of sink box and mold requiring 3230 kg of narrow steel in the mold required only 481 kg of narrow steel in the sink box (13% of the whole cast), when it was filled with it - —3 has the insulating lid described. A saving of 91 kg of steel per litter was made. For this particular practice, the open hard oven produced 41 castings with the conventional lid and 42 castings with the lid of this invention.

Claims

Patent claim:

A heat retaining lid for use in the open upper spirit of a mold or in a sink box in which narrow metal is cast, and comprising a bottom layer of exothermic material, a non-combustible separating plate above the bottom layer and a layer of insulating material above the separating plate, characterized in that predetermined thicknesses of the exothermic material (3) and of the insulating material (5) are arranged below resp. above the partition plate (10) inside a water-expandable container (1), said layer and the partition plate being separate from each other. Lid according to claim 1, characterized in that one of the bearings (3, 5) consists of loose material. Lid according to patent claim 1 or 2, characterized in that the container. (1) in a 15.da provided with slidable tabs (6, 6a or 6 ') for connecting a handling tool to the lid to facilitate its placement on top of the molten metal. 4. A lid according to any one of the preceding patent claims, characterized in that the separating plate (10) is a rigid plate, e.g. a thin metal plate or a ceramic plate. AnfOrda Publications: Patents from France 1,054,492; United Kingdom 604 043; USA 2,462,255, 2,462,256, 2,663,920. Stockholm 196

2. Kungl. Boktr. P. A. Norstedt & Hiner. 620089