EP0019015B1 - Foundry core for producing hardly accessible hollow cavities in casting pieces, and process for its manufacture - Google Patents
Foundry core for producing hardly accessible hollow cavities in casting pieces, and process for its manufacture Download PDFInfo
- Publication number
- EP0019015B1 EP0019015B1 EP79105250A EP79105250A EP0019015B1 EP 0019015 B1 EP0019015 B1 EP 0019015B1 EP 79105250 A EP79105250 A EP 79105250A EP 79105250 A EP79105250 A EP 79105250A EP 0019015 B1 EP0019015 B1 EP 0019015B1
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- casting
- core
- cores
- manufacture
- hollow cavities
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- 238000005266 casting Methods 0.000 title claims description 39
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 238000000034 method Methods 0.000 title claims description 8
- 150000003839 salts Chemical class 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 9
- 239000000956 alloy Substances 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims 1
- 210000005239 tubule Anatomy 0.000 claims 1
- 239000011162 core material Substances 0.000 description 34
- 239000007789 gas Substances 0.000 description 10
- 239000011230 binding agent Substances 0.000 description 9
- 229920003002 synthetic resin Polymers 0.000 description 6
- 239000000057 synthetic resin Substances 0.000 description 6
- 239000002585 base Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- MIDXCONKKJTLDX-UHFFFAOYSA-N 3,5-dimethylcyclopentane-1,2-dione Chemical compound CC1CC(C)C(=O)C1=O MIDXCONKKJTLDX-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- CZMRCDWAGMRECN-UHFFFAOYSA-N Rohrzucker Natural products OCC1OC(CO)(OC2OC(CO)C(O)C(O)C2O)C(O)C1O CZMRCDWAGMRECN-UHFFFAOYSA-N 0.000 description 1
- 240000000111 Saccharum officinarum Species 0.000 description 1
- 235000007201 Saccharum officinarum Nutrition 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000002152 aqueous-organic solution Substances 0.000 description 1
- 235000013736 caramel Nutrition 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 239000007859 condensation product Substances 0.000 description 1
- 239000008121 dextrose Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- IVJISJACKSSFGE-UHFFFAOYSA-N formaldehyde;1,3,5-triazine-2,4,6-triamine Chemical compound O=C.NC1=NC(N)=NC(N)=N1 IVJISJACKSSFGE-UHFFFAOYSA-N 0.000 description 1
- SLGWESQGEUXWJQ-UHFFFAOYSA-N formaldehyde;phenol Chemical compound O=C.OC1=CC=CC=C1 SLGWESQGEUXWJQ-UHFFFAOYSA-N 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 235000011837 pasties Nutrition 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- ODGAOXROABLFNM-UHFFFAOYSA-N polynoxylin Chemical compound O=C.NC(N)=O ODGAOXROABLFNM-UHFFFAOYSA-N 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000012262 resinous product Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/26—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of carbohydrates; of distillation residues therefrom
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/10—Cores; Manufacture or installation of cores
- B22C9/105—Salt cores
Definitions
- the invention relates to a casting core for producing cavities in castings made of aluminum or one of its alloys from a granular base substance and a sugar derivative which are mixed in solution, pressed into molds and baked at elevated temperature (DE-ANr. 1783004), as well as a process for producing such casting cores.
- the synthetic resin or synthetic resin of DE-A No. 1783004 are those of the urea formaldehyde type, phenol formaldehyde type, melamine formaldehyde type, urea furfuryl type, phenol furfuryl type or of the type based on sugar or glycose or compatible compositions of such resins.
- DE-A No. 2746122 discloses a core material for casting cores which, in addition to a water-soluble salt, contains a granulate of a metal and a synthetic resin which are mixed in solution in a manner known per se, pressed into molds and baked out at elevated temperature. This document also describes the use of core holders using tubes.
- sintered salt cores are relatively complex and they are too brittle for some applications. Furthermore, it is relatively difficult to remove them from the casting after the metal has been cast around them.
- Resin-bonded salt cores have the disadvantage that large amounts of gas can be released from the binder when used under the influence of the casting temperature. To avoid porosity in the casting, these gases must be removed quickly and completely. Due to the mostly narrow cross-sections, which are given by the geometry of the cast parts, blockages can easily occur in the outflow channels due to the condensation of resinous products. The result is an uncontrolled occurrence of the gases from the entire core surface with the known disadvantageous consequences for the casting.
- the invention is therefore based on the object to provide casting cores and processes for their production, from which, under the action of the temperatures during the casting of aluminum and its alloys, only small gases, if any, are released, the nature of the reaction products being such that gas can also be removed through thin channels without condensation products in these channels leading to blockages.
- the core material should be easy to remove from the cavity from possibly very narrow openings, either by dissolving the base substance or by disintegrating the binder, in which the base substance becomes free-flowing again.
- This object is achieved by creating a casting core of the type mentioned at the outset, which is characterized in that the binder used to bind the water-soluble salt represents sugar color in a concentration of 0.3 to 15% by weight, based on the total weight of the casting core .
- the disadvantages mentioned above can be avoided by using sugar color as a binder. It is particularly advantageous here that the casting cores according to the invention release only very small amounts of combustion gases from the binder at the casting temperatures, it not forming pasty condensates through which the outflow channels could be restricted or blocked.
- Sugar color which is also called caramel, is usually a more or less dark-colored mass that arises when sugar cane, beet sugar or dextrose - if necessary with the addition of some alkali - is heated to higher temperatures.
- the water-soluble salt which is bound with sugar color is in granular form. Such a configuration generally facilitates the dissolution or removal of the same.
- metal tubes e.g. by pressing, introduced in such a way that they can later be used both for fastening the cores in the casting mold and for removing the reaction gases during the casting process.
- the tubes used in this way can be flanged in the manner of hollow rivets, slotted on the side or perforated, on the one hand in order to ensure a firm fit in the core material and on the other hand in order to achieve easy removal of the gases.
- tubes e.g. made of metal, which are designed such that they offer the possibility of connection to a suction line outside the casting mold.
- the casting cores are produced by a process according to the invention in such a way that the water-soluble salt with 0.3 to 15% by weight of sugar color in aqueous, organic or mixed aqueous-organic solution is mixed in a known manner, pressed into molds and baked at elevated temperature .
- the proportion of the solvent used can vary within wide limits, since particularly favorable results were obtained with a weight ratio of solvent to organic binder of about 1: 1 to 1:10.
- the base substance is kept at a slightly higher temperature than the room temperature when it is coated with the binder.
- the basic substance in the coating with the binder may have a temperature between 20 and 180 ° C., the mixing process required for the coating then being continued until a dry, free-flowing mixture has formed.
- the subsequent pressing process advantageously also takes place at elevated temperatures. Press temperatures in the range between 50 and 200 ° C. are preferred.
- the baking which usually follows the pressing, is also carried out at an elevated temperature. Temperatures between 150 and 300 ° C have proven to be favorable.
- the time required for the baking depends on the type of sugar color chosen and the baking temperature, and it can usually comprise periods of about 10 minutes to about 2 hours for the baking temperatures indicated above.
- drying or removal of the solvent can be accelerated or promoted by increasing the temperature by introducing warm dry air.
- the casting cores according to the invention are illustrated schematically in a preferred embodiment in the attached figure.
- a cooling channel toroidal core 1 which is used to produce a cooling channel in the piston of an internal combustion engine, is shown in the casting core.
- the molded tubes 2 are used for attachment in the core receptacles 3 of the casting mold and at the same time for gas discharge.
- the casting cores according to the invention have particular advantages. In this way, the cores can be washed out of the finished castings without any effort, for example by adding water.
- a further advantage of the casting cores according to the invention, but also of the process for their production, is that neither during the production of the cores nor during the casting process or during subsequent washing out of the core residues, gases, vapors or waste materials are produced or released from the casting, which are released in any one would be environmentally harmful. Apart from this, as already stated above, the amount of gas released is relatively small.
- the binder based on sugar color has excellent disintegration properties, since its binding power is largely destroyed when the casting is poured.
- the basic substance which is largely in the form of a pour after the casting has cooled, can then be easily removed from the resulting cavity by simply shaking it out or by rinsing.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Molecular Biology (AREA)
- Mold Materials And Core Materials (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
Description
Die Erfindung betrifft einen Giesskern zur Erzeugung schwer zugänglicher Hohlräume in Gussstücken aus Aluminium oder aus einer seiner Legierungen aus einer körnigen Grundsubstanz und einem Zuckerderivat, die in Lösung vermischt, in Formen verpresst und bei erhöhter Temperatur ausgebacken sind (DE-ANr. 1783004), sowie ein Verfahren zur Herstellung solcher Giesskerne.The invention relates to a casting core for producing cavities in castings made of aluminum or one of its alloys from a granular base substance and a sugar derivative which are mixed in solution, pressed into molds and baked at elevated temperature (DE-ANr. 1783004), as well as a process for producing such casting cores.
Giesskerne für die Herstellung komplizierter oder schwer zugänglicher Hohlräume mit engen Querschnitten in Metallgussteilen, die wasserlösliche Kerne darstellen, sind bereits bekannt. In der DE-C Nr. 1302940 werden gesinterte Salzkerne beschrieben. Nach einer Weiterentwicklung gemäss DE-A Nr. 1783004 wird das wasserlösliche Kernmaterial mit einem synthetischen Harz bzw. Kunstharz gebunden. Als synthetisches Harz bzw. Kunstharz der DE-A Nr. 1783004 dienen solche vom Harnstofformaldehydtyp, Phenolformaldehydtyp, Melaminformaldehydtyp, Harnstofffurfuryltyp, Phenolfurfuryltyp oder vom auf Zucker-oder Glykosebasis aufgebauten Typ bzw. verträgliche Zusammensetzungen solcher Harze.Casting cores for the production of complicated or difficult to access cavities with narrow cross sections in metal castings, which are water-soluble cores, are already known. DE-C No. 1302940 describes sintered salt cores. According to a further development according to DE-A No. 1783004, the water-soluble core material is bound with a synthetic resin or synthetic resin. The synthetic resin or synthetic resin of DE-A No. 1783004 are those of the urea formaldehyde type, phenol formaldehyde type, melamine formaldehyde type, urea furfuryl type, phenol furfuryl type or of the type based on sugar or glycose or compatible compositions of such resins.
DE-A Nr. 2746122 offenbart ein Kernmaterial für Giesskerne, welches neben einem wasserlöslichen Salz ein Granulat eines Metalls sowie ein Kunstharz enthält, die in an sich bekannter Weise in Lösung vermischt, in Formen verpresst und bei erhöhter Temperatur ausgebacken werden. Diese Druckschrift beschreibt ausserdem den Einsatz von Kernhalterungen mittels Röhrchen.DE-A No. 2746122 discloses a core material for casting cores which, in addition to a water-soluble salt, contains a granulate of a metal and a synthetic resin which are mixed in solution in a manner known per se, pressed into molds and baked out at elevated temperature. This document also describes the use of core holders using tubes.
Die vorbekannten Giesskerne vermögen jedoch in ihren Eigenschaften noch nicht vollständig zu befriedigen, da sowohl die gesinterten Salzkerne wie auch solche mit Kunstharzbindung bei vielen Anwendungszwecken noch Nachteile aufweisen.However, the properties of the previously known casting cores are still not entirely satisfactory, since both the sintered salt cores and those with a synthetic resin bond still have disadvantages in many applications.
So ist die Herstellung gesinterter Salzkerne relativ aufwendig und diese sind auch für einige Anwendungszwecke zu spröde. Weiterhin lassen sie sich nach dem Umgiessen mit dem Metall nur relativ schwierig aus dem Gussstück herauslösen.The production of sintered salt cores is relatively complex and they are too brittle for some applications. Furthermore, it is relatively difficult to remove them from the casting after the metal has been cast around them.
Kunstharzgebundene Salzkerne haben dagegen den Nachteil, dass bei ihrer Anwendung unter Einwirkung der Giesstemperatur grosse Gasmengen aus dem Bindemittel freigesetzt werden können. Zur Vermeidung einer Porosität im Gussstück müssen diese Gase schnell und vollständig abgeführt werden. Aufgrund der zumeist engen Querschnitte, die durch die Geometrie der Gussteile gegeben sind, kann es aber in den Abströmkanälen leicht zu Verstopfungen durch Kondensation harzartiger Produkte kommen. Als Folge ergibt sich dann ein unkontrolliertes Auftreten der Gase aus der gesamten Kernoberfläche mit den bekannten nachteiligen Folgen für das Gussstück.Resin-bonded salt cores, on the other hand, have the disadvantage that large amounts of gas can be released from the binder when used under the influence of the casting temperature. To avoid porosity in the casting, these gases must be removed quickly and completely. Due to the mostly narrow cross-sections, which are given by the geometry of the cast parts, blockages can easily occur in the outflow channels due to the condensation of resinous products. The result is an uncontrolled occurrence of the gases from the entire core surface with the known disadvantageous consequences for the casting.
Der Erfindung liegt daher die Aufgabe zugrunde, Giesskerne und Verfahren zu deren Herstellung zu schaffen, aus denen unter Einwirkung der Temperaturen beim Giessen von Aluminium und dessen Legierungen, nur geringe Gase sofern überhaupt, freigesetzt werden, wobei die Art der Reaktionsprodukte so sein soll, dass auch die Gasabführung durch dünne Kanäle möglich ist, ohne dass Kondensationsprodukte in diesen Kanälen zu Verstopfungen führen. Insbesondere soll sich das Kernmaterial leicht aus eventuell sehr engen Öffnungen aus dem Hohlraum, sei es durch Auflösung der Grundsubstanz, sei es durch Zerfall des Bindemittels, bei dem die Grundsubstanz wieder rieselfähig wird, entfernen lassen.The invention is therefore based on the object to provide casting cores and processes for their production, from which, under the action of the temperatures during the casting of aluminum and its alloys, only small gases, if any, are released, the nature of the reaction products being such that gas can also be removed through thin channels without condensation products in these channels leading to blockages. In particular, the core material should be easy to remove from the cavity from possibly very narrow openings, either by dissolving the base substance or by disintegrating the binder, in which the base substance becomes free-flowing again.
Diese Aufgabe wird durch die Schaffung eines Giesskerns der eingangs genannten Art gelöst, der dadurch gekennzeichnet ist, dass das zur Bindung des wasserlöslichen Salzes eingesetzte Bindemittel Zuckercouleur in einer Konzentration von 0,3 bis 15 Gew.%, bezogen auf das Gesamtgewicht des Giesskerns, darstellt.This object is achieved by creating a casting core of the type mentioned at the outset, which is characterized in that the binder used to bind the water-soluble salt represents sugar color in a concentration of 0.3 to 15% by weight, based on the total weight of the casting core .
Im Rahmen der Erfindung ist überraschenderweise gefunden worden, dass durch den Einsatz von Zuckercouleur als Bindemittel die vorstehend erwähnten Nachteile vermieden werden können. Hierbei ist insbesondere vorteilhaft, dass die erfindungsgemässen Giesskerne bei den Giesstemperaturen nur sehr geringe Mengen an Verbrennungsgasen aus dem Bindemittel freisetzen, wobei es nicht zur Bildung pastöser Kondensate kommt, durch die die Abströmkanäle eingeengt bzw. verstopft werden könnten.It has surprisingly been found within the scope of the invention that the disadvantages mentioned above can be avoided by using sugar color as a binder. It is particularly advantageous here that the casting cores according to the invention release only very small amounts of combustion gases from the binder at the casting temperatures, it not forming pasty condensates through which the outflow channels could be restricted or blocked.
Zuckercouleur, das auch Karamel genannt wird, ist üblicherweise eine mehr oder weniger dunkel gefärbte Masse, die entsteht, wenn man Rohrzukker, Rübenzucker oder Traubenzucker - gegebenenfalls unter Zusatz von etwas Alkali - auf höhere Temperaturen erhitzt.Sugar color, which is also called caramel, is usually a more or less dark-colored mass that arises when sugar cane, beet sugar or dextrose - if necessary with the addition of some alkali - is heated to higher temperatures.
Nach einer Ausführungsform der Erfindung liegt das wasserlösliche Salz, welches mit Zuckercouleur gebunden wird, in körniger Form vor. Durch eine derartige Konfiguration wird die Auflösung bzw. Entfernung desselben im Regelfall erleichtert.According to one embodiment of the invention, the water-soluble salt which is bound with sugar color is in granular form. Such a configuration generally facilitates the dissolution or removal of the same.
Nach einer bevorzugten Ausführungsform der Erfindung werden in die mitZuckercouleurgebundenen Kerne bei deren Herstellung Metallröhrchen, z.B. durch Verpressen, derart mit eingeführt, dass sie später sowohl zur Befestigung der Kerne in der Giessform als auch zur Abführung der Reaktionsgase während des Giessvorganges dienen können. Die derart eingesetzten Röhrchen können, einerseits um einen festen Sitz im Kernmaterial und andererseits um eine leichte Abführung der Gase zu erreichen, in der Art von Hohlnieten umgebördelt, seitlich geschlitzt oder perforiert sein.According to a preferred embodiment of the invention, metal tubes, e.g. by pressing, introduced in such a way that they can later be used both for fastening the cores in the casting mold and for removing the reaction gases during the casting process. The tubes used in this way can be flanged in the manner of hollow rivets, slotted on the side or perforated, on the one hand in order to ensure a firm fit in the core material and on the other hand in order to achieve easy removal of the gases.
Zur Befestigung der Kerne in der Giessform können ebenfalls Röhrchen, z.B. aus Metall, vorgesehen sein, die derart ausgebildet sind, dass sie ausserhalb der Giessform die Möglichkeit des Anschlusses an eine Saugleitung bieten.To fix the cores in the mold, tubes, e.g. made of metal, which are designed such that they offer the possibility of connection to a suction line outside the casting mold.
Die Giesskerne werden nach einem Verfahren gemäss der Erfindung derart hergestellt, dass das wasserlösliche Salz mit 0,3 bis 15 Gew.% Zuckercouleur in wässeriger, organischer oder gemischt wässerig-organischer Lösung in bekannter Weise vermischt, in Formen verpresst und bei erhöhter Temperatur ausgebacken wird. Wenngleich der Anteil des eingesetzten Lösungsmittels in weite Grenzen schwanken kann, wurden doch besonders günstige Ergebnisse bei einem Gewichtsverhältnis von Lösungsmittel zu organischem Bindemittel von etwa 1 :1 bis 1 :10 erhalten.The casting cores are produced by a process according to the invention in such a way that the water-soluble salt with 0.3 to 15% by weight of sugar color in aqueous, organic or mixed aqueous-organic solution is mixed in a known manner, pressed into molds and baked at elevated temperature . Although the The proportion of the solvent used can vary within wide limits, since particularly favorable results were obtained with a weight ratio of solvent to organic binder of about 1: 1 to 1:10.
Für die Herstellung von Giesskernen für bestimmte Anwendungszwecke kann es günstig sein, wenn die Grundsubstanz bei der Umhüllung mit dem Bindemittel auf einer gegenüber der Raumtemperatur etwas erhöhten Temperatur gehalten wird. So kann die Grundsubstanz bei der Umhüllung mit dem Bindemittel beispielsweise eine Temperatur zwischen 20 und 180° C aufweisen, wobei der für die Umhüllung erforderliche Mischvorgang dann so lange fortgesetzt wird, bis ein trockenes rieselfähiges Gemisch entstanden ist.For the production of casting cores for certain applications, it can be advantageous if the base substance is kept at a slightly higher temperature than the room temperature when it is coated with the binder. For example, the basic substance in the coating with the binder may have a temperature between 20 and 180 ° C., the mixing process required for the coating then being continued until a dry, free-flowing mixture has formed.
Der nachfolgende Verpressungsvorgang erfolgt vorteilhafterweise ebenfalls bei erhöhten Temperaturen. Hierbei sind Presstemperaturen im Bereich zwischen 50 und 200° C bevorzugt.The subsequent pressing process advantageously also takes place at elevated temperatures. Press temperatures in the range between 50 and 200 ° C. are preferred.
Das Ausbacken, das üblicherweise auf die Verpressung folgt, wird ebenfalls bei erhöhter Temperatur vorgenommen. Hierbei haben sich Temperaturen zwischen 150 und 300° C als günstig erwiesen. Die für das Ausbacken erforderliche Zeit richtet sich nach der Art der gewählten Zuckercouleur und der Ausbacktemperatur, wobei sie für die vorstehend angegebenen Ausbacktemperaturen üblicherweise Zeiträume von etwa 10 min bis etwa 2 h umfassen kann.The baking, which usually follows the pressing, is also carried out at an elevated temperature. Temperatures between 150 and 300 ° C have proven to be favorable. The time required for the baking depends on the type of sugar color chosen and the baking temperature, and it can usually comprise periods of about 10 minutes to about 2 hours for the baking temperatures indicated above.
Bei der Herstellung des erfindungsgemässen Giesskerns kann die Trocknung bzw. die Entfernung des Lösungsmittels durch Temperaturerhöhung durch Einleiten warmer trockener Luft beschleunigt bzw. begünstigt werden.In the production of the casting core according to the invention, drying or removal of the solvent can be accelerated or promoted by increasing the temperature by introducing warm dry air.
Die erfindungsgemässen Giesskerne sind in der beigefügten Figur in einer bevorzugten Ausführungsform schematisch veranschaulicht. In der Figur ist bei dem Giesskern ein Kühlkanal-Ringkern 1, der zur Herstellung eines Kühlkanals im Kolben einer Brennkraftmaschine dient, gezeigt. Die eingeformten Röhrchen 2 dienen zur Befestigung in den Kernaufnahmen 3 der Giessform und zugleich zur Gasableitung.The casting cores according to the invention are illustrated schematically in a preferred embodiment in the attached figure. In the figure, a cooling channel
Die erfindungsgemässen Giesskerne weisen besondere Vorteile auf. So lassen sich die Kerne aus den fertigen Gussteilen ohne jegliche Mühe, beispielsweise durch Wasserzufuhr, auswaschen. Ein weiterer Vorteil der erfindungsgemässen Giesskerne aber auch des Verfahrens zu deren Herstellung besteht darin, dass weder bei der Herstellung der Kerne noch während des Giessvorganges oder beim späteren Auswaschen der Kernreste aus dem Gussstück Gase, Dämpfe oder Abfallstoffe entstehen bzw. freigesetzt werden, die in irgendeiner Weise umweltschädlich wären. Abgesehen davon ist, wie bereits vorstehend ausgeführt wurde, die Menge an freigesetztem Gas relativ gering.The casting cores according to the invention have particular advantages. In this way, the cores can be washed out of the finished castings without any effort, for example by adding water. A further advantage of the casting cores according to the invention, but also of the process for their production, is that neither during the production of the cores nor during the casting process or during subsequent washing out of the core residues, gases, vapors or waste materials are produced or released from the casting, which are released in any one Would be environmentally harmful. Apart from this, as already stated above, the amount of gas released is relatively small.
Schliesslich ist zu erwähnen, dass das Bindemittel auf der Basis von Zuckercouleur ausgezeichnete Zerfallseigenschaften aufweist, da seine Bindekraft beim Giessen des Gussstückes weitgehend zerstört wird. Die Grundsubstanz, die nach dem Erkalten des Gussstückes in weitgehend rieselförmiger Form vorliegt, lässt sich dann durch einfaches Ausrütteln oder aber durch Spülen aus dem entstandenen Hohlraum leicht entfernen.Finally, it should be mentioned that the binder based on sugar color has excellent disintegration properties, since its binding power is largely destroyed when the casting is poured. The basic substance, which is largely in the form of a pour after the casting has cooled, can then be easily removed from the resulting cavity by simply shaking it out or by rinsing.
Die Herstellung des erfindungsgemässen Giesskernswird nachstehend in einem Ausführungsbeispiel erläutert, das nicht als Einschränkung aufzufassen ist.The production of the casting core according to the invention is explained below in an exemplary embodiment, which should not be interpreted as a limitation.
Zur Herstellung von 100 kg Kernmaterial wurden 2,7 kg Zuckercouleur mit 0,3 kg Alkohol verdünnt und in dieser Form einer Menge von 97 kg NaCI bei einer Temperatur von 120° C zugegeben und einem schonend arbeitenden Mischer zugeführt. Bereits nach kurzer Zeit waren die Salzkörner vom Bindematerial umhüllt und konnten durch Einleiten warmer Luft getrocknet werden. Sobald die Mischung wieder rieselfähig war, wurde sie in ein Pressgesenk der gewünschten Form gebracht und dort verdichtet, wobei das Verdichtungsverhältnis 1,4:1 betrug. Das Pressgesenk selbst wurde dabei auf einer Temperatur von 140° C gehalten. Es enthielt in einer entsprechenden Halterung die seitlich geschlitzten und in Form einer Hohlniete ausgebildeten Röhrchen. Der so hergestellte Kern wurde dem Pressgesenk mit Hilfe einer entsprechenden Vorrichtung entnommen und anschliessend auf einer, der Kernform angepassten Unterlage während 60 min bei 220° C ausgebakken.To produce 100 kg of core material, 2.7 kg of sugar color were diluted with 0.3 kg of alcohol and, in this form, an amount of 97 kg of NaCl was added at a temperature of 120 ° C. and fed to a gentle mixer. After a short time, the salt grains were enveloped by the binding material and could be dried by introducing warm air. As soon as the mixture was free-flowing again, it was brought into a press die of the desired shape and compacted there, the compression ratio being 1.4: 1. The die itself was kept at a temperature of 140 ° C. In a suitable holder, it contained the laterally slotted tubes, which were designed in the form of hollow rivets. The core produced in this way was removed from the press die with the aid of an appropriate device and then baked on a base adapted to the core shape at 220 ° C. for 60 minutes.
Claims (3)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792917208 DE2917208A1 (en) | 1979-04-27 | 1979-04-27 | CASTING CORE FOR GENERATING HARD ACCESSIBLE CAVES IN CASTING PIECES, AND METHOD FOR THE PRODUCTION THEREOF |
| DE2917208 | 1979-04-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0019015A1 EP0019015A1 (en) | 1980-11-26 |
| EP0019015B1 true EP0019015B1 (en) | 1983-04-27 |
Family
ID=6069469
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP79105250A Expired EP0019015B1 (en) | 1979-04-27 | 1979-12-18 | Foundry core for producing hardly accessible hollow cavities in casting pieces, and process for its manufacture |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4361181A (en) |
| EP (1) | EP0019015B1 (en) |
| JP (1) | JPS55144352A (en) |
| BR (1) | BR8000487A (en) |
| CA (1) | CA1158014A (en) |
| DE (1) | DE2917208A1 (en) |
| ES (2) | ES488019A0 (en) |
| PT (1) | PT70731A (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS606266A (en) * | 1983-06-27 | 1985-01-12 | Toyota Motor Corp | Production of metal-base composite material |
| DE3530924A1 (en) * | 1985-08-29 | 1987-03-12 | Alcan Aluminiumwerke | HEAT-RESISTANT COMPONENT AND METHOD FOR THE PRODUCTION THEREOF |
| DE3831285A1 (en) * | 1987-09-17 | 1989-04-06 | Aisin Seiki | METHOD FOR PRODUCING A PISTON OF AN INTERNAL COMBUSTION ENGINE |
| US4925492A (en) * | 1987-09-21 | 1990-05-15 | The Interlake Corporation | Ceramic core for investment casting and method for preparation |
| DE3903310C2 (en) * | 1989-02-04 | 1992-10-22 | Mahle Gmbh | METHOD FOR PRODUCING A MOLDED PART FROM IN PARTICULAR TO BE PROVIDED WITH A POROUS NIGHT-DUTY, IN PARTICULAR ALUMINUM. |
| JPH074646B2 (en) * | 1989-02-20 | 1995-01-25 | リョービ株式会社 | Sand core for high pressure casting and method for producing the same |
| JPH02220733A (en) * | 1989-02-22 | 1990-09-03 | Aisin Seiki Co Ltd | Manufacture of piston for internal combustion engine |
| US6557621B1 (en) | 2000-01-10 | 2003-05-06 | Allison Advanced Development Comapny | Casting core and method of casting a gas turbine engine component |
| US6478073B1 (en) | 2001-04-12 | 2002-11-12 | Brunswick Corporation | Composite core for casting metallic objects |
| DE10312782B4 (en) * | 2003-03-21 | 2005-05-04 | Emil Müller GmbH | Water-soluble salt cores and process for producing water-soluble salt cores |
| EP2316592A1 (en) | 2003-09-17 | 2011-05-04 | Yaokawa Jun | Core for use in casting |
| US7406941B2 (en) * | 2004-07-21 | 2008-08-05 | Federal - Mogul World Wide, Inc. | One piece cast steel monobloc piston |
| US7013948B1 (en) | 2004-12-01 | 2006-03-21 | Brunswick Corporation | Disintegrative core for use in die casting of metallic components |
| DE102006031531A1 (en) | 2006-07-07 | 2008-01-10 | Emil Müller GmbH | Salt cores for plastic (injection) casting |
| DE102006031532B3 (en) | 2006-07-07 | 2008-04-17 | Emil Müller GmbH | Water-soluble salt core with functional component |
| WO2009065015A1 (en) * | 2007-11-14 | 2009-05-22 | University Of Northern Iowa Research Foundation | Bio-based binder system |
| US8426494B2 (en) * | 2009-10-06 | 2013-04-23 | Amcol International Corp. | Lignite urethane based resins for enhanced foundry sand performance |
| JP6565011B2 (en) * | 2015-05-29 | 2019-08-28 | リグナイト株式会社 | Mold manufacturing method |
| DE112018000221B4 (en) | 2017-01-25 | 2023-02-16 | Technische Universität Bergakademie Freiberg | Process for the manufacture of high-temperature resistant products with improved thermomechanical properties and high-temperature resistant product |
| JP2021098212A (en) * | 2019-12-23 | 2021-07-01 | トヨタ自動車株式会社 | Method for producing salt core |
| US11724306B1 (en) | 2020-06-26 | 2023-08-15 | Triad National Security, Llc | Coating composition embodiments for use in investment casting methods |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA787804A (en) * | 1968-06-18 | Starr Clive | Foundry moulding sand compositions | |
| US2926098A (en) * | 1955-10-14 | 1960-02-23 | Diamond Alkali Co | Binder for foundry molds |
| GB1240877A (en) * | 1968-07-26 | 1971-07-28 | British Non Ferrous Metals Res | Foundry moulding sand compositions |
| GB1275618A (en) * | 1968-09-04 | 1972-05-24 | Int Minerals & Chem Corp | Clay and water soluble graft copolymer compositions |
| US3645491A (en) * | 1969-07-22 | 1972-02-29 | Aeroplane Motor Aluminum Casti | Soluble metal casting cores comprising a water-soluble salt and a synthetic resin |
| DE2111615A1 (en) * | 1971-03-11 | 1972-09-14 | Tasic Zivko Dipl Chem | Foundry sand compsn - contg quartz sand and sugar-contg soln |
| DE2250568A1 (en) * | 1972-10-14 | 1974-04-18 | Porsche Ag | Cores for engine block casting moulds - are made from easily removed soluble substances |
| FR2237704A1 (en) * | 1973-07-16 | 1975-02-14 | Prod Du Mais | Cement-sand mixes for moulds and cores - using dextrose-calcium chloride mixt. as catalyst for rapid setting |
| JPS52123319A (en) * | 1976-04-08 | 1977-10-17 | Hirofumi Matsui | Molding sand composion |
| DE2746122C3 (en) * | 1977-10-13 | 1981-02-05 | Alcan Aluminiumwerk Nuernberg Gmbh, 6000 Frankfurt | Core mass for foundry cores |
-
1979
- 1979-04-27 DE DE19792917208 patent/DE2917208A1/en not_active Withdrawn
- 1979-12-18 EP EP79105250A patent/EP0019015B1/en not_active Expired
-
1980
- 1980-01-25 JP JP770780A patent/JPS55144352A/en active Pending
- 1980-01-25 BR BR8000487A patent/BR8000487A/en unknown
- 1980-01-25 ES ES488019A patent/ES488019A0/en active Granted
- 1980-01-25 PT PT70731A patent/PT70731A/en unknown
- 1980-02-04 CA CA000345011A patent/CA1158014A/en not_active Expired
- 1980-09-12 ES ES495002A patent/ES495002A0/en active Granted
-
1982
- 1982-01-18 US US06/339,863 patent/US4361181A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| ES8104929A1 (en) | 1981-05-16 |
| BR8000487A (en) | 1980-12-30 |
| CA1158014A (en) | 1983-12-06 |
| DE2917208A1 (en) | 1980-12-04 |
| ES488019A0 (en) | 1981-05-16 |
| ES8105595A1 (en) | 1981-06-16 |
| EP0019015A1 (en) | 1980-11-26 |
| PT70731A (en) | 1980-02-01 |
| ES495002A0 (en) | 1981-06-16 |
| US4361181A (en) | 1982-11-30 |
| JPS55144352A (en) | 1980-11-11 |
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