EP0344225A1 - Process for manufacturing a casting mould. - Google Patents

Process for manufacturing a casting mould.

Info

Publication number
EP0344225A1
EP0344225A1 EP88907601A EP88907601A EP0344225A1 EP 0344225 A1 EP0344225 A1 EP 0344225A1 EP 88907601 A EP88907601 A EP 88907601A EP 88907601 A EP88907601 A EP 88907601A EP 0344225 A1 EP0344225 A1 EP 0344225A1
Authority
EP
European Patent Office
Prior art keywords
molding material
material mixture
casting
mold
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP88907601A
Other languages
German (de)
French (fr)
Other versions
EP0344225B1 (en
Inventor
Ludwig Wilhelm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Georg Fischer AG
Original Assignee
Georg Fischer AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Georg Fischer AG filed Critical Georg Fischer AG
Publication of EP0344225A1 publication Critical patent/EP0344225A1/en
Application granted granted Critical
Publication of EP0344225B1 publication Critical patent/EP0344225B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • B22C1/162—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 use of a gaseous treating agent for hardening the binder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/12—Treating moulds or cores, e.g. drying, hardening

Definitions

  • the present invention relates to a method for producing a casting mold in the manner of a block mold, from a granular molding material mixture, for casting preferably coreless castings, and casting molds produced by the method.
  • the known molding processes such as shaking, pressing, blowing, shooting or high-pressure pressing, have in common that molding materials with additives such as bentonite are used. Since the old sand accumulated when the castings are emptied is reused and must therefore be processed accordingly, any type of additive in the molding material - for the process of reprocessing - is problematic.
  • the object of the present invention is to propose a method for producing a casting mold from a granular molding material mixture, in which there are no reactive additives to the liquid metal.
  • the casting mold produced by the process should be environmentally friendly and easy to process.
  • quartz sand is first mixed with water glass, the water glass serving as a binder. Fumigation with carbonic acid rapidly solidifies the molding material. Silica gels are formed with the elimination of water, which firmly bind the quartz sand.
  • the bonding introduced by the carbon dioxide allows the mold to be separated from the model without damage.
  • the pourable final hardness is set by exposure to microwaves.
  • a casting mold 1 according to the invention has molded parts 2 and 3 modeled on both sides with cavities already molded. Several such molds are produced for series production, two of them each be pushed together in a block so that a complete casting cavity is created. This not only brings optimal use of the shape, but also leads to economical series production.
  • Directional solidification can be achieved by providing cooling bores 4 which can be supplied with air as the cooling medium.
  • Sand with the designation M36 and 5% water glass (e.g. Kernex) was used for the mold production. After carbonation, the molds were placed in the microwave oven. The oven was operated for 5 minutes at a power level that corresponds to an energy output of about 700 watts. Loss of water has increased the form strength.
  • the mold After the casting and solidification of the metal in the mold, the mold can be dissolved in water. The castings are then cleaned by blasting. The lowering of the mold in the water can be carried out in various stages, which means that a change in the structure of the casting can be avoided or set in a targeted manner.
  • the sand detached in the water is fed to the reprocessing after drying, whereby this reprocessing can be carried out in an environmentally friendly process without additional manipulations, since no additives are used, e.g. Bentonite, coal dust or other additives.
  • the mold produced in the proposed way is very high. Has solidity, there is no feeder for gray-rigid materials.
  • the cast body cast in this form has a good surface due to the low penetration.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Abstract

In a process for manufacturing casting moulds from a granular mixture of mould materials, gaseous carbon dioxide is passed briefly through the mixture of mould materials which is then dried by microwaves. The mixture of mould materials consists preferably of silica sand with a low, ca. 5 %, water-glass content. The moulds are easy to manufacture and possess high hardness. They are soluble in water and their preparation is non-polluting.

Description

Verfahren zur Herstellung einer Giessform - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ¬ Process for producing a casting mold - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ¬
Die vorliegende Erfindung betrifft ein Verfahren zur HerStellung einer Giessform in der Art einer Blockform, aus einer körnigen Formstoffmischung, zum Abgiessen von vorzugsweise kernlosen Gussstücken, sowie Giessformen, hergestellt nach dem Verfahren.The present invention relates to a method for producing a casting mold in the manner of a block mold, from a granular molding material mixture, for casting preferably coreless castings, and casting molds produced by the method.
Es gibt verschiedene Verfahren zur Herstellung von Giessformen aus einem körnigen Formstoffgemisch. Um eine Formstoffmasse zum Abgiessen von flüssigem Metall verwendbar zu machen, muss zunächst eine Verdichtung der Fo rmst of fmas se erfolgen. Die Giessform muss ausreichende Festigkeitswerte aufweisen, um dem ferrostatischen Druck der flüssigen Metallschmelze standzuhalten.There are various methods for producing casting molds from a granular molding material mixture. In order to make a molding material usable for pouring liquid metal, the mold must first be compacted. The mold must have sufficient strength values to withstand the ferrostatic pressure of the molten metal.
Den bekannten Formverfahren, wie z.B. Rütteln, Pressen, Blasen, Schiessen oder Hochdruckpressen ist gemeinsam, dass Formstoffe mit Zusatzstoffen wie z.B. Bentonit verwendet werden. Da der beim Ausleeren der Gussstücke anfallende Altsand wieder verwendet wird, und deshalb entsprechend aufbereitet werden muss, ist jede Art von Zusatz im Formstoff - für den Vorgang der Wiederaufbereitung - problematisch. Aufgabe der vorliegenden Erfindung ist es, ein Verfahren zur Herstellung einer Giessform aus einer körnigen Formstoffmis chung vorzuschlagen, bei dem keine reaktiven Zusätze gegenüber dem flüssigen Metall vorhanden sind. Die nach dem Verfahren hergestellte Giessform soll umweltschonend und auf einfache Art und Weise aufbereitet werden können.The known molding processes, such as shaking, pressing, blowing, shooting or high-pressure pressing, have in common that molding materials with additives such as bentonite are used. Since the old sand accumulated when the castings are emptied is reused and must therefore be processed accordingly, any type of additive in the molding material - for the process of reprocessing - is problematic. The object of the present invention is to propose a method for producing a casting mold from a granular molding material mixture, in which there are no reactive additives to the liquid metal. The casting mold produced by the process should be environmentally friendly and easy to process.
Diese Aufgabe wird erf indungsgemäss durch den kennzeichnenden Teil des Anspruches 1 gelöst.According to the invention, this object is achieved by the characterizing part of claim 1.
Weitere vorteilhafte Ausgestaltungen gehen aus den abhängigen Ansprüchen hervor.Further advantageous configurations emerge from the dependent claims.
Zur Herstellung einer Giessform in der Art einer Blockform aus einer körnigen Formstoffmasse wird zunächst einmal feinkörniger Quarzsand mit Wasserglas gemischt, wobei das Wasserglas als Binder dient. Durch Begasung mit Kohlensäure erfolgt eine rasche Erstarrung der Formstoffmasse. Es bilden sich unter Wasserabspaltung Kieselsäuregele, die den Quarzsand fest abbinden.To produce a casting mold in the manner of a block mold from a granular molding material mixture, fine-grained quartz sand is first mixed with water glass, the water glass serving as a binder. Fumigation with carbonic acid rapidly solidifies the molding material. Silica gels are formed with the elimination of water, which firmly bind the quartz sand.
Die durch die Kohlensäure eingeleitete Abbindung gestattet die Form vom Modell beschädigungsfrei zu trennen.The bonding introduced by the carbon dioxide allows the mold to be separated from the model without damage.
Die giessfähige Endhärte wird durch Mikrowelleneinwirkung eingestelIt.The pourable final hardness is set by exposure to microwaves.
Anhand der Figur wird eine bevorzugte Ausführungsform näher beschrieben.A preferred embodiment is described in more detail with reference to the figure.
Eine erfindungsgemässe Giessform 1 weist zweiseitig modellierte Formteile 2 und 3 auf mit bereits eingeformten Hohlräumen. Für die Serienfertigung werden mehrere solche Giessformen hergestellt, von denen jeweils je zwei zu einem Block zusammengeschoben werden, so dass ein kompletter Giesshohlräum entsteht. Dies bringt nicht nur eine optimale Ausnützung der Form mit sich, sondern führt auch zu einer wirtschaftlichen Serienfertigung.A casting mold 1 according to the invention has molded parts 2 and 3 modeled on both sides with cavities already molded. Several such molds are produced for series production, two of them each be pushed together in a block so that a complete casting cavity is created. This not only brings optimal use of the shape, but also leads to economical series production.
Durch Anbringung von Kühlbohrungen 4, die mit Luft als Kühlmedium beaufschlagt werden können, kann eine gerichtete Erstarrung bewerkstelligt werden.Directional solidification can be achieved by providing cooling bores 4 which can be supplied with air as the cooling medium.
Für die Formherstellung wurde Sand mit der Bezeichnung M36 und 5 % Wasserglas (z.B. Kernex) verwendet. Nach Begasung mit Kohlensäure wurden die Formen in den Mikrowellenofen gelegt. Während 5 Min. wurde der Ofen mit einer Leistungsstufe gefahren, die einer Energieabgabe von etwa 700 Watt entspricht. Durch Wasserverlust ist eine Erhöhung derFormfestigkeit eingetreten.Sand with the designation M36 and 5% water glass (e.g. Kernex) was used for the mold production. After carbonation, the molds were placed in the microwave oven. The oven was operated for 5 minutes at a power level that corresponds to an energy output of about 700 watts. Loss of water has increased the form strength.
Nach dem Abguss und dem Erstarren des Metalls in der Form kann die Form im Wasser aufgelöst werden. Die Gussstücke werden dann durch Strahlen fertiggeputzt. Das Absenken der Form im Wasser kann in verschiedenen Stufen gesteuert erfolgen, womit eine Gefügeveränderung im Gussstück sicher vermieden oder auch gezielt eingestellt werden kann.After the casting and solidification of the metal in the mold, the mold can be dissolved in water. The castings are then cleaned by blasting. The lowering of the mold in the water can be carried out in various stages, which means that a change in the structure of the casting can be avoided or set in a targeted manner.
Der im Wasser abgelöste Sand wird nach dem Trocknen der erneuten Aufbereitung zugeführt, wobei diese Aufbereitung ohne zusätzliche Manipulationen in einem umweltschonenden Verfahren erfolgen kann, da keine Zusatzstoffe verwendet werden wie z.B. Bentonit, Kohlenstaub oder andere Additiven.The sand detached in the water is fed to the reprocessing after drying, whereby this reprocessing can be carried out in an environmentally friendly process without additional manipulations, since no additives are used, e.g. Bentonite, coal dust or other additives.
Da die auf die vorgeschlagene Art und Weise hergestellte Giessform eine sehr hohe. Festigkeit aufweist, ist ein speiserloses Giessen für grauerstarrende Werkstoffe gegeben. Der in dieser Form abgegossene Gusskörper weist eine gute Oberfläche als Folge der geringen Penetration auf.Since the mold produced in the proposed way is very high. Has solidity, there is no feeder for gray-rigid materials. The cast body cast in this form has a good surface due to the low penetration.
Die erhaltenen genauen Abgüsse erfordern keine wesentliche Nachbehandlung.The exact casts obtained do not require any significant post-treatment.
Die Vorteile der nach dem beschriebenen Verfahren hergestellten Form sind vielfältig:There are many advantages to the shape produced using the described method:
- Verfahren ist voll automatisierbar- The process can be fully automated
- Da nur anorganische Stoffe, CO2, Wasserglas, SiO2 (Quarzsand verwendet werden, ist das Verfahren physiologisch unbedenklich. Während und nach Abguss entstehen keine störenden Geruchsentwicklungen.- Since only inorganic substances, CO 2 , water glass, SiO 2 (quartz sand are used), the process is physiologically harmless. During and after casting there are no unpleasant odors.
- Das Auspacken erfolgt im Wasser. Dadurch werden Staubbelastigungen vermieden.- Unpacking takes place in the water. This avoids dust pollution.
- Umweltschonende, verlustarme Sandaufbereitung.- Environmentally friendly, low-loss sand preparation.
- Geringer Energieaufwand. - Low energy consumption.

Claims

P a t e n t a n s p r ü c h e - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Patent claims - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1. Verfahren zur Herstellung einer Giessform in der Art einer Blockform aus einer körnigen Formstoffmis chung zum Abgiessen von vorzugsweise kernlosen Gussstücken, gekennzeichnet durch die folgenden Verfahrensschritte:1. A process for producing a casting mold in the manner of a block mold from a granular molding material mixture for casting preferably coreless castings, characterized by the following process steps:
- eine Formstoffmischung, die eine vorbestimmte Menge Wasserglas enthält, wird in einen Formkasten, der ein Modell enthält, eingebracht,a molding material mixture containing a predetermined amount of water glass is placed in a molding box containing a model,
- die Formstoffmis chung wird während einer bestimmten Zeit mit CO2-Gas beaufschlagt,- The molding material mixture is exposed to CO 2 gas for a certain time,
- ansch liessend wird die Formstoff mis chung unter Einwirkung von Mikrowellen verfestigt.- The molding compound is then solidified under the influence of microwaves.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass als Formstoffmischung Quarzsand und Wasserglas verwendet wird.2. The method according to claim 1, characterized in that quartz sand and water glass is used as the molding material mixture.
3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass die Einwirkzeit der Mikrowellen so eingestellt wird, dass die Formstoffm is chung auf Endhärte austrocknet.3. The method according to claim 1, characterized in that the exposure time of the microwaves is set so that the molding material mixture dries out to its final hardness.
4. Giessform hergestellt nach dem Verfahren nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass sie im Wasser löslich ist. 4. casting mold produced by the method according to any one of claims 1 to 3, characterized in that it is soluble in water.
5. Verwendung der Giessform zum Abgiessen von Kurbel-, Nokkenwellen, Pleueln und Schwungscheiben. 5. Use of the casting mold for casting crankshafts, camshafts, connecting rods and flywheels.
EP88907601A 1987-09-18 1988-09-15 Process for manufacturing a casting mould Expired - Lifetime EP0344225B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH3608/87A CH675973A5 (en) 1987-09-18 1987-09-18
CH3608/87 1987-09-18
PCT/CH1988/000161 WO1989002325A1 (en) 1987-09-18 1988-09-15 Process for manufacturing a casting mould

Publications (2)

Publication Number Publication Date
EP0344225A1 true EP0344225A1 (en) 1989-12-06
EP0344225B1 EP0344225B1 (en) 1994-08-17

Family

ID=4259648

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88907601A Expired - Lifetime EP0344225B1 (en) 1987-09-18 1988-09-15 Process for manufacturing a casting mould

Country Status (6)

Country Link
EP (1) EP0344225B1 (en)
JP (1) JPH02501204A (en)
AT (1) ATE110016T1 (en)
CH (1) CH675973A5 (en)
DE (1) DE3851143D1 (en)
WO (1) WO1989002325A1 (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB745402A (en) * 1952-07-09 1956-02-22 Wilhelm Schmidt Improvements in or relating to a process for the production of moulds and cores for foundry purposes
DE1030525B (en) * 1952-11-13 1958-05-22 Gutehoffnungshuette Sterkrade Process for the production of molded masks
FR1322512A (en) * 1962-05-02 1963-03-29 Siemens Ag Method and apparatus for constructing dimensionally stable foundry molds and cores from molding sands and binders
FR1517167A (en) * 1967-03-09 1968-03-15 Usines Belges Vynckier Freres Process for curing a sand-based composition and installation for carrying out this process
JPS58100938A (en) * 1981-12-11 1983-06-15 Sintokogio Ltd Molding method for mold

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8902325A1 *

Also Published As

Publication number Publication date
JPH02501204A (en) 1990-04-26
WO1989002325A1 (en) 1989-03-23
DE3851143D1 (en) 1994-09-22
CH675973A5 (en) 1990-11-30
ATE110016T1 (en) 1994-09-15
EP0344225B1 (en) 1994-08-17

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