EP0673698A1 - Method for the production of moulds - Google Patents

Method for the production of moulds Download PDF

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Publication number
EP0673698A1
EP0673698A1 EP94120497A EP94120497A EP0673698A1 EP 0673698 A1 EP0673698 A1 EP 0673698A1 EP 94120497 A EP94120497 A EP 94120497A EP 94120497 A EP94120497 A EP 94120497A EP 0673698 A1 EP0673698 A1 EP 0673698A1
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EP
European Patent Office
Prior art keywords
pressure
molding material
plate
compression
compressed air
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EP94120497A
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German (de)
French (fr)
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EP0673698B1 (en
Inventor
Herbert Dipl.-Ing. Grolla
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Heinrich Wagner Sinto Maschinenfabrik GmbH
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Heinrich Wagner Sinto Maschinenfabrik GmbH
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor
    • B22C15/28—Compacting by different means acting simultaneously or successively, e.g. preliminary blowing and finally pressing

Definitions

  • the invention relates to a device for producing casting molds, with a model plate provided with a model, with a mold box which can be placed on the model plate for receiving a compressible molding material, in particular molding sand, and with a compression device which can be placed on the mold box, with a pneumatic precompression and at least a stamp for mechanical compression of the molding material.
  • Vent holes can be omitted if necessary; however, mechanical post-compression can also be associated with constant compressed air purging of the molding material.
  • the object of the invention is therefore to design a device of the type specified at the outset in such a way that that with their help and by means of a single pressure ram, both in the pneumatic pre-compression and in the mechanical post-compression, the molding material can be compacted uniformly with an approximately constant surface pressure over the entire surface of the molding material, regardless of the shape of the overmolded model.
  • the device should also make it possible to carry out the pre-compression of the molding material both with a constant pressure gradient of the compressed air with an effective outflow via the ventilation holes and with a brief pressure pulse to which the compressed air is exposed.
  • the object is achieved in that the pressure stamp is elastically deformable at least in the area of its pressure surface, that a pressure chamber is provided in the compression device above the pressure stamp, in which the compressed air supply opens, and that through holes are arranged in the pressure stamp, which one between the Pneumatically connect the surface of the molding material and the mold cavity formed with the pressure chamber.
  • the through holes in the plunger are expediently distributed so that the surface of the molding material is exposed to the same pressure from the compressed air throughout. In this way, the entire configuration of the molding space is exposed to this static pressure of the compressed air, and pressure drops within the molding space and thus, in particular, along the surface of the molding material are largely avoided.
  • the effect of the mechanical post-compression is not affected by the arrangement of the through bores, because the outer shape of the pressure stamp is not impaired and the shape of the models can still be flexibly followed.
  • vent holes for the compressed air are provided in the model plate and the through holes are dimensioned according to the number and cross section are that during the pre-compression there is a uniform flow of the molding material
  • the through holes can be dimensioned in terms of number and cross-section so that during pulsed compressed air feeding into the pressure chamber the air pressure built up there is also instantaneous in the molding space above the surface of the molding material; vent holes for the compressed air can also be provided in the model plate.
  • the arrangement and dimensioning of the through holes and any ventilation holes can be determined by tests. Of course, it also depends on the type of molding material, the specific geometric conditions and the pressures and forces used.
  • the pressure stamp is composed of an at least partially elastically deformable pressure plate and a rigid frame enclosing the pressure plate outside the pressure surface.
  • the pressure plunger can be conveniently guided in the housing of the device and connected to the piston rod of the pressure piston.
  • the frame of the pressure plate by the frame also ensures that permanent deformations of the pressure plate are avoided because the pressure plate cannot flow under the influence of the possibly high applied pressure force.
  • the pressure plate consists of several interconnected plate layers transversely to their direction of movement, which in turn can consist of materials of different elasticity, the elasticity of the plate layers expediently increasing in the direction of the printing surface.
  • the printing plate is in one Case can be carried out very dimensionally stable, even if the printing surface is highly elastic.
  • the elasticity of the pressure plate in particular in the area of its pressure surface, is dimensioned such that during the mechanical re-compression of the molding material the outlets of the through holes which are in contact with the molding material through the pressure plate acting reaction forces are contracted.
  • the pressure surface of the pressure stamp that actually loads the molding material increases during the post-compression, and the squeezed outlets no longer act as defects in the pressure surface.
  • the device according to the invention for generating a pressure pulse for precompression can be set up in such a way that the pressure chamber consists of two subspaces which are separated from one another by a partition which is fixed to the housing of the compression device and extends transversely to the direction of movement of the pressure stamp, and which means in the partition provided openings are pneumatically connectable to each other, and that the piston rod is guided through the partition, whereby an interruptible pneumatic connection of the two subspaces can be produced, for example, in such a way that the openings in the partition and the through holes offset relative to one another transversely to the direction of movement of the pressure stamp are arranged so that the subspaces are pneumatically separated from one another when the plunger bears against the partition.
  • a compressed air possibly with a high air pressure, can be provided in the partial space connected to the compressed air supply, which compressed air only reaches the second partial space above the molding material when the pressure stamp moves away from the partition towards the molding material is moved; the through holes are blocked as long as the pressure stamp is still against the partition. In this way, the molding material can suddenly be exposed to high air pressure.
  • a filling frame can be arranged between the compression device and the molding box.
  • the invention eliminates the disadvantages of the prior art in a surprisingly simple manner and does not require any significant additional effort; on the other hand, it can be used universally in the embodiment described and combines the advantages of the known devices with elastic pressure stamps with the advantages of a uniform pneumatic pre-compression.
  • a device initially consists, according to FIG. 1, of a compression device 1 which is placed on a molding box 3 via a filling frame 2.
  • the molding box 3 in turn sits on a model plate 4 on which the models 5 (here two) to be molded are located.
  • the molding box 3 and part of the filling frame 2 are filled with a molding material 6, over the (horizontal) surface 61 of which a molding space 12 is formed in a housing 11 of the compression device 1, which is also delimited by a pressure surface 13a of a pressure stamp 13.
  • the pressure stamp 13 is movable in the housing 11, the filling frame 2 and the molding box 3 in the vertical direction by means of (here four) pressure pistons 14, as far as the molding material 6 permits.
  • Vent holes 41 are provided in the model plate 4, which pneumatically connect the interior of the molding box 3 and thus the molding space 12 to the surroundings of the device.
  • Vent holes 41 inserted screens 42 prevent the passage of molding material 6.
  • the piston-like pressure stamp 13 has a pressure plate 13b which is clamped in a frame 13c on all sides, in this case the pressure surface 13a located on the pressure plate 13b and acting on the surface 61 of the molding material 6 and also leaving part of the pressure plate 13b itself free.
  • the frame 13c is also used for the axially movable mounting of the pressure plunger 13 in the housing 11 and for attachment to piston rods 14a of the pressure pistons 14 fixedly installed on the housing 11.
  • the piston rods 14a are located above the pressure plunger 13 in a pressure chamber enclosed by the latter and the housing 11 15, which can be connected via a compressed air supply 16 to a compressed air source omitted in the drawing via a shut-off device 17.
  • the flow direction and paths of the compressed air are illustrated in the drawing by direction arrows.
  • the relatively large flow cross section of the compressed air supply 16 compared to the second embodiment described below is intended to make it clear that a compressed air flow that is to be maintained constantly requires a high compressed air throughput under certain circumstances.
  • This flow of compressed air takes place via through bores 13d in the plunger 13, which pneumatically connect the pressure chamber 15 to the mold chamber 12 in an axially parallel manner.
  • FIG. 2 it can be seen that a multiplicity of through bores 13d approximately equally spaced from one another are arranged; in the same way it can be seen that there are four piston rods 14a which also belong to a total of four pressure pistons 14.
  • the mold space 12 which is more real in FIG. 1 and the opened shut-off device 17 indicate that the pneumatic precompression of the molding material 6 has started. 3, the shut-off device 17 is closed, and instead the pressure plunger 13 is raised onto the molding material 6 by actuation of the pressure piston 14 for mechanical post-compression of the molding material 6, so that the molding space 12 has disappeared.
  • the elasticity of the pressure plate 13b can be controlled by its design so that the outlets 13e of the through bores 13d facing the molding material 6 are squeezed together under the influence of the reaction force exerted by the molding material 6 and only narrow slits remain.
  • the pressure plate 13b which is only partially clamped on its circumference in the frame 13c, is also deformed by the reaction force of the molding material 6 in the region of the edges of the pressure surface 13a in the direction of the housing 11, as in FIG. 3 (and also in FIG. 5) is indicated.
  • the axis guidance of the pressure stamp 13 in the housing 11 is thereby improved.
  • FIGS. 4 and 5 differs only slightly from the variant of FIGS. 1 to 3 described in detail above ; it is therefore sufficient to state the main changes.
  • Fig. 4 it can be seen that the pressure chamber 15 'is divided into two by a partition 18 which is fixedly clamped in the housing 11', in such a way that the compressed air supply 16 'opens into an upper section 15a.
  • the representation of the compressed air supply 16 'and also the shut-off device 17' is intended to symbolically indicate that in this second embodiment, a flow cross-section which is substantially smaller than that of the first is sufficient for the compressed air flowing into the pressure chamber 15 '.
  • the pressure ram 13 ' is still attached to the piston rod 14a' of a (here only) pressure piston 14 'and is initially under its influence on the underside of the partition wall 18, leaving a molding space 12' above the surface 61 'of the molding material 6' .
  • the partition wall 18 is provided with a number of openings 18a comparable in size to that of the through bores 13d '; however, these are axially offset from the through bores 13d ', so that when the frame 13c abuts the partition 18, the pressure chamber 15' of the molding chamber 12 'is pneumatic is separated; A high pressure potential can form in the subspace 15a, even with compressed air flowing in only moderately quickly from the compressed air supply 16 ', which also loads the pressure ram 13'.
  • the pressure plunger 13 ' is only slightly removed by the pressure piston 14' from the partition 18 and moved downward at such a pressure potential, a subspace 15b of the pressure space 15 'is created, and the compressed air expanding into the subspace 15b can be accessed via the now accessible Through holes 13d 'suddenly load the molding material 6' and pre-compress in a pulsed manner.
  • the subspace 15b is further enlarged in accordance with FIG. 5 when the mechanical post-compression is initiated by means of the pressure piston 14 ', the course of which does not differ from that of the embodiment in FIGS. 1 to 3; consequently, it is also conceivable here that the shut-off device 17 'shown closed in FIG. 5 is still open and compressed air flows through the molding material 6' during mechanical post-compression.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Casting Devices For Molds (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)

Abstract

The appts. comprises a pattern plate (4), a mould box (3) and a compression unit (1) for pneumatic preliminary compression and mechanical final compression by means of a pressure ram (13). The appts. is characterised by the following features: (a) the pressure ram (13) is elastically deformable at least within the region of its pressure area (13a); (b) a pressure space (15) is located above the pressure ram and is connected to a compressed air supply; and (c) the pressure ram is provided with bores (13d) connecting the mould space (12) above the mould material (6) with the pressure space (15).

Description

Die Erfindung betrifft eine Vorrichtung zur Herstellung von Gießformen, mit einer mit einem Modell versehenen Modellplatte, mit einem auf die Modellplatte aufsetzbaren Formkasten zur Aufnahme eines verdichtbaren Formstoffes, insbesondere eines Formsandes, und mit einer auf den Formkasten aufsetzbaren Verdichtungseinrichtung, mit einer pneumatischen Vorverdichtung und mindestens einem Druckstempel für eine mechanische Nachverdichtung des Formstoffes.The invention relates to a device for producing casting molds, with a model plate provided with a model, with a mold box which can be placed on the model plate for receiving a compressible molding material, in particular molding sand, and with a compression device which can be placed on the mold box, with a pneumatic precompression and at least a stamp for mechanical compression of the molding material.

Aus der EP-Patentschrift 0 319 453 B1 ist ein Verfahren zum Verdichten von körnigem Formstoff bekannt, bei dem der Formstoff auch während des mechanischen Nachverdichtens von Druckluft durchströmt wird und wo zu diesem Zweck Entlüftungsbohrungen für die Druckluft in der Modellplatte der Vorrichtung vorgesehen sind; der Luftdruck kann dabei im Vergleich zu dem vorangehenden pneumatischen Vorverdichten verhältnismäßig niedrig gehalten werden, so daß man von einer Durchspülung des Formsandes sprechen kann.From EP patent 0 319 453 B1 a method for compressing granular molding material is known, in which compressed air flows through the molding material even during the mechanical post-compression and where ventilation holes for the compressed air are provided in the model plate of the device for this purpose; the air pressure can be kept relatively low in comparison to the previous pneumatic precompression, so that one can speak of a flushing of the molding sand.

Stattdessen ist es aber auch möglich, das Vorverdichten mittels einer einem relativ kurzzeitigen Druckimpuls ausgesetzten Druckluft zu betreiben, bei dem auf Entlüftungsbohrungen gegebenenfalls verzichtet werden kann; jedoch kann auch hier das mechanische Nachverdichten mit einer konstanten Druckluft-Durchspülung des Formstoffes verbunden sein.Instead, however, it is also possible to operate the pre-compression by means of a compressed air which is exposed to a relatively short-term pressure pulse Vent holes can be omitted if necessary; however, mechanical post-compression can also be associated with constant compressed air purging of the molding material.

Um eine gleichförmige Nachverdichtung unabhängig von der Form des Modells zu erhalten, ist es aus der Britischen Patentanmeldung GB 2 046 644 A seit langem bekannt, eine größere Anzahl parallel bewegter Druckstempel zu verwenden, die außerdem entsprechend der Europäischen Patentschrift 0 263 977 B1 auch unabhängig voneinander verschiebbar sein können.In order to obtain a uniform post-compression regardless of the shape of the model, it has long been known from British patent application GB 2 046 644 A to use a larger number of parallel stamps, which according to European patent 0 263 977 B1 are also independent of one another can be displaceable.

Den gleichen Zweck verfolgt, unabhängig von der Art der jeweils verwendeten Vorverdichtung, eine Anordnung entsprechend der US-Patentschrift 3,401,685 dadurch, daß der (einzige) Druckstempel für die mechanische Nachverdichtung elastisch ausgebildet ist. Auf diese Weise werden zwar die mit einer Vielzahl von Druckstempeln verbundenen höheren Kosten vermieden, und einer gleichförmigen Nachverdichtung kommt eine solche Ausführung zweifellos näher, als dies bei der Verwendung eines einzigen starren Druckstempels möglich ist. Die Druckverteilung in dem Formstoff ist aber nun während der pneumatischen Vorverdichtung nicht mehr gleichförmig, weil die währenddessen um den Druckstempel herumgeleitete Druckluft eine auf der gesamten Oberfläche des Formstoff gleichhohe Flächenpressung nicht aufzubauen vermag, insbesondere dann, wenn eine Abströmung durch den Formstoff und die Modellplatte erfolgen soll. Eine einwandfreie Nachverdichtung hängt aber unter anderem auch davon ab, ob es gelungen ist, bereits während der Vorverdichtung für eine von der Modellkontur und der Kontur des Druckstempels unabhängige, oberflächendeckend gleichförmige Verdichtung des Formstoffes zu sorgen.An arrangement according to US Pat. No. 3,401,685 pursues the same purpose, irrespective of the type of precompression used, in that the (only) pressure stamp for the mechanical post-compression is elastic. In this way, the higher costs associated with a large number of pressure stamps are avoided, and such a design is undoubtedly closer to uniform post-compression than is possible when using a single rigid pressure stamp. However, the pressure distribution in the molding material is no longer uniform during the pneumatic pre-compression, because the compressed air that is directed around the pressure ram cannot build up a surface pressure of the same level on the entire surface of the molding material, especially if there is an outflow through the molding material and the model plate should. Flawless post-compaction also depends, among other things, on whether it was possible to ensure that the molding material was uniformly compact and independent of the model contour and the contour of the pressure stamp during pre-compaction.

Die Erfindung hat sich deshalb die Aufgabe gestellt, eine Vorrichtung der eingangs näher bezeichneten Art so auszubilden, daß mit deren Hilfe und mittels eines einzigen Druckstempels sowohl bei der pneumatischen Vorverdichtung als auch bei der mechanischen Nachverdichtung der Formstoff unabhängig von der Form des überformten Modells gleichförmig mit einer über der gesamten Oberfläche des Formstoffes ungefähr konstanten Flächenpressung verdichtet werden kann. Die Vorrichtung soll es ferner ermöglichen, die Vorverdichtung des Formstoffes sowohl mit einem konstanten Druckgefälle der Druckluft bei wirkender Abströmung über die Entlüftungsbohrungen als auch mit einem kurzzeitigen Druckimpuls auszuführen, der die Druckluft ausgesetzt wird.The object of the invention is therefore to design a device of the type specified at the outset in such a way that that with their help and by means of a single pressure ram, both in the pneumatic pre-compression and in the mechanical post-compression, the molding material can be compacted uniformly with an approximately constant surface pressure over the entire surface of the molding material, regardless of the shape of the overmolded model. The device should also make it possible to carry out the pre-compression of the molding material both with a constant pressure gradient of the compressed air with an effective outflow via the ventilation holes and with a brief pressure pulse to which the compressed air is exposed.

Erfindungsgemäß wird die Aufgabe dadurch gelöst, daß der Druckstempel mindestens im Bereich seiner Druckfläche elastisch verformbar ist, daß in der Verdichtungseinrichtung oberhalb des Druckstempels ein Druckraum vorgesehen ist, in dem die Druckluftzuführung mündet, und daß in dem Druckstempel Durchgangsbohrungen angeordnet sind, welche einen zwischen der Oberfläche des Formstoffes und dem Druckstempel ausgebildeten Formraum mit dem Druckraum pneumatisch verbinden. Die Durchgangsbohrungen in dem Druckstempel sind dabei zweckmäßig so verteilt, daß die Oberfläche des Formstoffes durchweg dem gleichen Druck aus der Druckluft ausgesetzt ist. Auf diese Weise ist der Formraum in seiner Gesamtkonfiguration diesem statischen Druck der Druckluft ausgesetzt, und es werden Druckgefälle innerhalb des Formraumes und damit vor allem entlang der Oberfläche des Formstoffes weitgehend vermieden. Andererseits ist Wirkung der mechanischen Nachverdichtung durch die Anordnung der Durchgangsbohrungen nicht betroffen, weil der Druckstempel in seinem äußeren Umriß nicht beeinträchtigt ist und auch weiterhin der Kontur der Modelle flexibel folgen kann.According to the invention the object is achieved in that the pressure stamp is elastically deformable at least in the area of its pressure surface, that a pressure chamber is provided in the compression device above the pressure stamp, in which the compressed air supply opens, and that through holes are arranged in the pressure stamp, which one between the Pneumatically connect the surface of the molding material and the mold cavity formed with the pressure chamber. The through holes in the plunger are expediently distributed so that the surface of the molding material is exposed to the same pressure from the compressed air throughout. In this way, the entire configuration of the molding space is exposed to this static pressure of the compressed air, and pressure drops within the molding space and thus, in particular, along the surface of the molding material are largely avoided. On the other hand, the effect of the mechanical post-compression is not affected by the arrangement of the through bores, because the outer shape of the pressure stamp is not impaired and the shape of the models can still be flexibly followed.

Es ist dabei einerseits möglich, daß in der Modellplatte Entlüftungsbohrungen für die Druckluft vorgesehen und die Durchgangsbohrungen nach Anzahl und Querschnitt so bemessen sind, daß während der Vorverdichtung eine gleichförmige Durchströmung des Formstoffes erfolgt, andererseits können die Durchgangsbohrungen nach Anzahl und Querschnitt aber auch so bemessen sein, daß während einer impulsartigen Druckluft-Einspeisung in den Druckraum der dabei dort aufgebaute Luftdruck verzögerungsfrei auch in dem Formraum über der Oberfläche des Formstoffes ansteht; auch dabei können in der Modellplatte Entlüftungsbohrungen für die Druckluft vorgesehen sein.On the one hand, it is possible that vent holes for the compressed air are provided in the model plate and the through holes are dimensioned according to the number and cross section are that during the pre-compression there is a uniform flow of the molding material, on the other hand the through holes can be dimensioned in terms of number and cross-section so that during pulsed compressed air feeding into the pressure chamber the air pressure built up there is also instantaneous in the molding space above the surface of the molding material; vent holes for the compressed air can also be provided in the model plate.

Die Anordnung und Bemessung der Durchgangs- und der eventuellen Entlüftungsbohrungen kann durch Versuche ermittelt werden. Sie ist selbstverständlich auch von der Art des Formstoffes, den spezifischen geometrischen Verhältnissen und den verwendeten Drücken und Kräften abhängig.The arrangement and dimensioning of the through holes and any ventilation holes can be determined by tests. Of course, it also depends on the type of molding material, the specific geometric conditions and the pressures and forces used.

Bei einer besonders vorteilhaften Ausführung der Erfindung ist der Druckstempel aus einer mindestens partiell elastisch verformbaren Druckplatte und einem die Druckplatte außerhalb der Druckfläche einfassenden, starren Rahmen zusammengesetzt. Auf diese Weise kann der Druckstempel bequem in dem Gehäuse der Vorrichtung geführt und an der Kolbenstange des Druckkolbens angeschlossen werden. Die Fassung der Druckplatte durch den Rahmen sorgt außerdem dafür, daß bleibende Verformungen der Druckplatte vermieden werden, weil ein Fließen der Druckplatte unter dem Einfluß der gegebenenfalls hohen anliegenden Druckkraft nicht stattfinden kann.In a particularly advantageous embodiment of the invention, the pressure stamp is composed of an at least partially elastically deformable pressure plate and a rigid frame enclosing the pressure plate outside the pressure surface. In this way, the pressure plunger can be conveniently guided in the housing of the device and connected to the piston rod of the pressure piston. The frame of the pressure plate by the frame also ensures that permanent deformations of the pressure plate are avoided because the pressure plate cannot flow under the influence of the possibly high applied pressure force.

Eine weitere Verbesserung der Wirkungsweise läßt sich erreichen. wenn die Druckplatte quer zu ihrer Bewegungsrichtung aus mehreren miteinander verbundenen Plattenschichten besteht, die wiederum aus Werkstoffen unterschiedlicher Elastizität bestehen können, wobei die Elastizität der Plattenschichten in Richtung auf die Druckfläche hin zweckmäßigerweise zunimmt. Die Druckplatte ist in einem solchen Fall sehr formstabil ausführbar, selbst dann, wenn die Druckfläche hochelastisch ist.A further improvement in the mode of action can be achieved. if the pressure plate consists of several interconnected plate layers transversely to their direction of movement, which in turn can consist of materials of different elasticity, the elasticity of the plate layers expediently increasing in the direction of the printing surface. The printing plate is in one Case can be carried out very dimensionally stable, even if the printing surface is highly elastic.

Es ist technisch möglich und für die Wirkungsweise der Erfindung besonders günstig, wenn die Elastizität der Druckplatte, insbesondere im Bereich ihrer Druckfläche, so bemessen ist, daß während der mechanischen Nachverdichtung des Formstoffes die dabei an dem Formstoff anliegenden Auslässe der Durchgangsbohrungen durch die auf die Druckplatte wirkenden Reaktionskräfte kontrahiert werden. Die den Formstoff tatsächlich belastende Druckfläche des Druckstempels nimmt infolgedessen während der Nachverdichtung zu, und die zusammengequetschten Auslässe werden in der Druckfläche nicht mehr als Störstellen wirksam.It is technically possible and particularly advantageous for the mode of operation of the invention if the elasticity of the pressure plate, in particular in the area of its pressure surface, is dimensioned such that during the mechanical re-compression of the molding material the outlets of the through holes which are in contact with the molding material through the pressure plate acting reaction forces are contracted. As a result, the pressure surface of the pressure stamp that actually loads the molding material increases during the post-compression, and the squeezed outlets no longer act as defects in the pressure surface.

In spezieller Weise kann die erfindungsgemäße Vorrichtung zur Erzeugung eines Druckimpulses für die Vorverdichtung dadurch eingerichtet werden, daß der Druckraum aus zwei von einer an dem Gehäuse der Verdichtungseinrichtung ortsfesten, quer zu der Bewegungsrichtung des Druckstempels verlaufenden Trennwand voneinander geschiedenen Teilräumen besteht, die mittels in der Trennwand vorgesehenen Durchbrechungen pneumatisch miteinander verbindbar sind, und daß die Kolbenstange durch die Trennwand geführt ist, wobei eine unterbrechbare pneumatische Verbindung der beiden Teilräume beispielsweise in der Weise herstellbar ist, daß die Durchbrechungen in der Trennwand und die Durchgangsbohrungen quer zu der Bewegungsrichtung des Druckstempels so zueinander versetzt angeordnet sind, daß bei an der Trennwand anliegendem Druckstempel die Teilräume pneumatisch voneinander getrennt sind. Auf diese Weise kann in dem mit der Druckluftzuführung verbundenen Teilraum eine mit einem gegebenenfalls hohen Luftdruck beaufschlagte Druckluft bereitgestellt werden, die nur dann in den zweiten, über dem Formstoff befindlichen Teilraum gelangt, wenn der Druckstempel von der Trennwand weg in Richtung auf den Formstoff bewegt wird; solange der Druckstempel noch an der Trennwand anliegt, sind die Durchgangsbohrungen gesperrt. Der Formstoff ist auf diese Weise schlagartig einem hohen Luftdruck aussetzbar.In a special way, the device according to the invention for generating a pressure pulse for precompression can be set up in such a way that the pressure chamber consists of two subspaces which are separated from one another by a partition which is fixed to the housing of the compression device and extends transversely to the direction of movement of the pressure stamp, and which means in the partition provided openings are pneumatically connectable to each other, and that the piston rod is guided through the partition, whereby an interruptible pneumatic connection of the two subspaces can be produced, for example, in such a way that the openings in the partition and the through holes offset relative to one another transversely to the direction of movement of the pressure stamp are arranged so that the subspaces are pneumatically separated from one another when the plunger bears against the partition. In this way, a compressed air, possibly with a high air pressure, can be provided in the partial space connected to the compressed air supply, which compressed air only reaches the second partial space above the molding material when the pressure stamp moves away from the partition towards the molding material is moved; the through holes are blocked as long as the pressure stamp is still against the partition. In this way, the molding material can suddenly be exposed to high air pressure.

Es ist zweckmäßig, wenn der Werkstoff für mindestens eine Plattenschicht inkompressibel ist. Im übrigen kann zwischen der Verdichtungseinrichtung und dem Formkasten ein Füllrahmen angeordnet sein.It is expedient if the material is incompressible for at least one plate layer. Otherwise, a filling frame can be arranged between the compression device and the molding box.

Die Erfindung beseitigt die Nachteile des Standes der Technik in überraschend einfacher Weise und erfordert auch keinen erheblichen Mehraufwand; sie ist hingegen in der beschriebenen Ausgestaltung außerordentlich universell einsetzbar und verbindet die Vorteile der bekannten Vorrichtungen mit elastischen Druckstempeln mit den Vorteilen einer gleichförmigen pneumatischen Vorverdichtung.The invention eliminates the disadvantages of the prior art in a surprisingly simple manner and does not require any significant additional effort; on the other hand, it can be used universally in the embodiment described and combines the advantages of the known devices with elastic pressure stamps with the advantages of a uniform pneumatic pre-compression.

Die Erfindung wird nachstehend an Hand der Zeichnung an einem Ausführungsbeispiel näher beschrieben. Es zeigen

Fig. 1
eine erste Ausführung einer erfindungsgemäßen Vorrichtung in geschnittener Vorderansicht während der pneumatischen Vorverdichtung,
Fig. 2
eine dem Schnittverlauf A - A folgende geschnittene Draufsicht zu Fig. 2,
Fig. 3
die Ausführung der Fig. 1 während der mechanischen Nachverdichtung,
Fig. 4
eine zweite Ausführung einer erfindungsgemäßen Vorrichtung in geschnittener Vorderansicht während der pneumatischen Vorverdichtung und
Fig. 5
die Ausführung der Fig. 4 während der mechanischen Nachverdichtung, sämtlich in schematisch vereinfachender Darstellung gezeichnet.
The invention is described below with reference to the drawing of an embodiment. Show it
Fig. 1
a first embodiment of a device according to the invention in a sectional front view during the pneumatic pre-compression,
Fig. 2
3 shows a sectional top view of FIG. 2 following the course of the section A - A,
Fig. 3
1 during the mechanical post-compression,
Fig. 4
a second embodiment of a device according to the invention in a sectional front view during the pneumatic precompression and
Fig. 5
4 during mechanical post-compression, all drawn in a schematically simplified representation.

Eine erfindungsgemäße Vorrichtung besteht zunächst entsprechend Fig. 1 aus einer Verdichtungseinrichtung 1, die über einen Füllrahmen 2 auf einen Formkasten 3 aufgesetzt ist. Der Formkasten 3 sitzt seinerseits auf einer Modellplatte 4 auf, auf der sich die (hier zwei) abzuformenden Modelle 5 befinden. Der Formkasten 3 und ein Teil des Füllrahmens 2 ist mit einem Formstoff 6 gefüllt, über dessen (waagerechter) Oberfläche 61 in einem Gehäuse 11 der Verdichtungseinrichtung 1 ein Formraum 12 ausgebildet ist, der außerdem von einer Druckfläche 13a eines Druckstempels 13 begrenzt ist. Der Druckstempel 13 ist in dem Gehäuse 11, dem Füllrahmen 2 und dem Formkasten 3 in senkrechter Richtung mittels (hier vierer) Druckkolben 14 bewegbar, soweit dies der Formstoff 6 zuläßt. In der Modellplatte 4 sind Entlüftungsbohrungen 41 vorgesehen, die das Innere des Formkastens 3 und damit den Formraum 12 pneumatisch mit der Umgebung der Vorrichtung verbinden. In dieA device according to the invention initially consists, according to FIG. 1, of a compression device 1 which is placed on a molding box 3 via a filling frame 2. The molding box 3 in turn sits on a model plate 4 on which the models 5 (here two) to be molded are located. The molding box 3 and part of the filling frame 2 are filled with a molding material 6, over the (horizontal) surface 61 of which a molding space 12 is formed in a housing 11 of the compression device 1, which is also delimited by a pressure surface 13a of a pressure stamp 13. The pressure stamp 13 is movable in the housing 11, the filling frame 2 and the molding box 3 in the vertical direction by means of (here four) pressure pistons 14, as far as the molding material 6 permits. Vent holes 41 are provided in the model plate 4, which pneumatically connect the interior of the molding box 3 and thus the molding space 12 to the surroundings of the device. In the

Entlüftungsbohrungen 41 eingesetzte Siebe 42 verhindern den Hindurchtritt von Formstoff 6.Vent holes 41 inserted screens 42 prevent the passage of molding material 6.

Der kolbenartige Druckstempel 13 weist eine Druckplatte 13b auf, die allseits, dabei die an der Druckplatte 13b befindliche, auf die Oberfläche 61 des Formstoffes 6 einwirkende Druckfläche 13a und auch einen Teil der Druckplatte 13b selbst freilassend, in einem Rahmen 13c eingespannt ist. Der Rahmen 13c dient außerdem zur achsbeweglichen Lagerung des Druckstempels 13 in dem Gehäuse 11 sowie zur Befestigung an Kolbenstangen 14a der auf dem Gehäuse 11 fest installierten Druckkolben 14. Die Kolbenstangen 14a befinden sich oberhalb des Druckstempels 13 in einem von diesem und dem Gehäuse 11 umschlossenen Druckraum 15, der über eine Druckluftzuführung 16 mit einer in der Zeichnung weggelassenen Druckluftquelle über eine Absperreinrichtung 17 verbindbar ist. Die Strömungsrichtung und -pfade der Druckluft sind in der Zeichnung durch Richtungspfeile veranschaulicht. Der im Vergleich zu der weiter unten beschriebenen zweiten Ausführung relativ große Strömungsquerschnitt der Druckluftzuführung 16 soll deutlich machen, daß eine konstant aufrechtzuerhaltende Druckluftströmung einen unter Umständen hohen Druckluftdurchsatz erfordert. Diese Druckluftströmung erfolgt über Durchgangsbohrungen 13d in dem Druckstempel 13, die achsparallel den Druckraum 15 mit dem Formraum 12 pneumatisch verbinden. In der Fig. 2 ist zu erkennen, daß eine Vielzahl etwa gleich weit voneinander entfernter Durchgangsbohrungen 13d angeordnet sind; in gleicher Weise ist sichtbar, daß vier Kolbenstangen 14a vorhanden sind, die zu insgesamt ebenfalls vier Druckkolben 14 gehören.The piston-like pressure stamp 13 has a pressure plate 13b which is clamped in a frame 13c on all sides, in this case the pressure surface 13a located on the pressure plate 13b and acting on the surface 61 of the molding material 6 and also leaving part of the pressure plate 13b itself free. The frame 13c is also used for the axially movable mounting of the pressure plunger 13 in the housing 11 and for attachment to piston rods 14a of the pressure pistons 14 fixedly installed on the housing 11. The piston rods 14a are located above the pressure plunger 13 in a pressure chamber enclosed by the latter and the housing 11 15, which can be connected via a compressed air supply 16 to a compressed air source omitted in the drawing via a shut-off device 17. The flow direction and paths of the compressed air are illustrated in the drawing by direction arrows. The relatively large flow cross section of the compressed air supply 16 compared to the second embodiment described below is intended to make it clear that a compressed air flow that is to be maintained constantly requires a high compressed air throughput under certain circumstances. This flow of compressed air takes place via through bores 13d in the plunger 13, which pneumatically connect the pressure chamber 15 to the mold chamber 12 in an axially parallel manner. In FIG. 2 it can be seen that a multiplicity of through bores 13d approximately equally spaced from one another are arranged; in the same way it can be seen that there are four piston rods 14a which also belong to a total of four pressure pistons 14.

Der in Fig. 1 realiter vorhandene Formraum 12 und die geöffnete Absperreinrichtung 17 zeigen an, daß die pneumatische Vorverdichtung des Formstoffes 6 in Gang gesetzt ist. Nach deren Beendigung ist entsprechend Fig. 3 die Absperreinrichtung 17 geschlossen, und stattdessen ist der Druckstempel 13 durch Betätigung der Druckkolben 14 zur mechanischen Nachverdichtung des Formstoffes 6 auf den Formstoff 6 aufgefahren, so daß der Formraum 12 verschwunden ist. Dabei kann die Elastizität der Druckplatte 13b durch deren konstruktive Ausbildung so gesteuert werden, daß die zu dem Formstoff 6 hin gerichteten Auslässe 13e der Durchgangsbohrungen 13d unter dem Einfluß der von dem Formstoff 6 ausgeübten Reaktionskraft zusammengequetscht werden und nur mehr schmale Schlitze übrigbleiben. Auf diese Weise entsteht eine relativ ungestörte Druckfläche 13a; gleichwohl genügen die verengten Auslässe 13e, eine Durchströmung von Druckluft auch während der mechanischen Nachverdichtung aufrechtzuerhalten, wenn die Absperreinrichtung 17 geöffnet bleibt. Die Oberfläche 61 des Formstoffes 6 ist nun nicht mehr eben, weil ihre Form bei dessen etwa raum-konstanter Verdichtung von den aufgelegten Modellen 5 beeinflußt wird.The mold space 12 which is more real in FIG. 1 and the opened shut-off device 17 indicate that the pneumatic precompression of the molding material 6 has started. 3, the shut-off device 17 is closed, and instead the pressure plunger 13 is raised onto the molding material 6 by actuation of the pressure piston 14 for mechanical post-compression of the molding material 6, so that the molding space 12 has disappeared. The elasticity of the pressure plate 13b can be controlled by its design so that the outlets 13e of the through bores 13d facing the molding material 6 are squeezed together under the influence of the reaction force exerted by the molding material 6 and only narrow slits remain. In this way, a relatively undisturbed printing surface 13a; nevertheless, the narrowed outlets 13e suffice to maintain a flow of compressed air even during mechanical post-compression if the shut-off device 17 remains open. The surface 61 of the molding material 6 is now no longer flat, because its shape is influenced by the models 5 when it is compacted approximately in space.

Die an ihrem Umfang nur teilweise in dem Rahmen 13c eingespannte Druckplatte 13b wird durch die Reaktionskraft des Formstoffes 6 im Bereich der Berandung der Druckfläche 13a auch in Richtung auf das Gehäuse 11 hin verformt, wie in Fig. 3 (und auch in Fig. 5) angedeutet ist. Die Achsführung des Druckstempels 13 in dem Gehäuse 11 wird dadurch verbessert.The pressure plate 13b, which is only partially clamped on its circumference in the frame 13c, is also deformed by the reaction force of the molding material 6 in the region of the edges of the pressure surface 13a in the direction of the housing 11, as in FIG. 3 (and also in FIG. 5) is indicated. The axis guidance of the pressure stamp 13 in the housing 11 is thereby improved.

Die Ausführung der Fig. 4 und 5, in der zu der Ausführung der Fig. 1 bis 3 gleiche Bauteile mit dem gleichen, aber jeweils einfach angestrichenen Bezugszeichen versehen sind, unterscheidet sich nur geringfügig von der oben ausführlich beschriebenen Variante der Fig. 1 bis 3; es genügt hier deshalb, die wesentlichen Veränderungen anzugeben.The embodiment of FIGS. 4 and 5, in which the same components as the embodiment of FIGS. 1 to 3 are provided with the same, but in each case simply underlined reference numerals, differs only slightly from the variant of FIGS. 1 to 3 described in detail above ; it is therefore sufficient to state the main changes.

In der Fig. 4 ist zu erkennen, daß der Druckraum 15' durch eine Trennwand 18 zweigeteilt ist, die in dem Gehäuse 11' ortsfest eingespannt ist, und zwar so, daß in einem oberen Teilraum 15a die Druckluftzuführung 16' mündet. Die Darstellungsweise der Druckluftzuführung 16' und auch der Absperreinrichtung 17' soll symbolisch anzeigen, daß man bei dieser zweiten Ausführung mit einem gegenüber der ersten wesentlich geringeren Strömungsquerschnitt für die in den Druckraum 15' einströmende Druckluft auskommt.In Fig. 4 it can be seen that the pressure chamber 15 'is divided into two by a partition 18 which is fixedly clamped in the housing 11', in such a way that the compressed air supply 16 'opens into an upper section 15a. The representation of the compressed air supply 16 'and also the shut-off device 17' is intended to symbolically indicate that in this second embodiment, a flow cross-section which is substantially smaller than that of the first is sufficient for the compressed air flowing into the pressure chamber 15 '.

Der Druckstempel 13' ist nach wie vor an der Kolbenstange 14a' eines (hier einzigen) Druckkolbens 14' befestigt und liegt zunächst unter dessen Einfluß an der Unterseite der Trennwand 18 an, einen Formraum 12' über der Oberfläche 61' des Formstoffes 6' freilassend.The pressure ram 13 'is still attached to the piston rod 14a' of a (here only) pressure piston 14 'and is initially under its influence on the underside of the partition wall 18, leaving a molding space 12' above the surface 61 'of the molding material 6' .

Die Trennwand 18 ist mit einer hinsichtlich der Größenordnung mit derjenigen der Durchgangsbohrungen 13d' vergleichbaren Anzahl von Durchbrechungen 18a versehen; diese sind aber gegenüber den Durchgangsbohrungen 13d' axial versetzt angeordnet, so daß bei an der Trennwand 18 anliegendem Rahmen 13c der Druckraum 15' von dem Formraum 12' pneumatisch getrennt ist; in dem Teilraum 15a kann sich, selbst bei aus der Druckluftzuführung 16' nur mäßig schnell einströmender Druckluft, ein hohes Druckpotential ausbilden, das auch den Druckstempel 13' belastet.The partition wall 18 is provided with a number of openings 18a comparable in size to that of the through bores 13d '; however, these are axially offset from the through bores 13d ', so that when the frame 13c abuts the partition 18, the pressure chamber 15' of the molding chamber 12 'is pneumatic is separated; A high pressure potential can form in the subspace 15a, even with compressed air flowing in only moderately quickly from the compressed air supply 16 ', which also loads the pressure ram 13'.

Wird unter einem solchen Druckpotential der Druckstempel 13' von dem Druckkolben 14' nur geringfügig von der Trennwand 18 entfernt und nach unten bewegt, dann wird entsteht ein Teilraum 15b des Druckraumes 15', und die in den Teilraum 15b expandierende Druckluft kann über die nun zugänglichen Durchgangsbohrungen 13d' den Formstoff 6' schlagartig belasten und impulsartig vorverdichten. Der Teilraum 15b wird entsprechend Fig. 5 weiter vergrößert, wenn mittels des Druckkolbens 14' die mechanische Nachverdichtung eingeleitet wird, deren Ablauf sich im übrigen von demjenigen der Ausführung in den Fig. 1 bis 3 nicht unterscheidet; demzufolge ist es auch hier denkbar, daß die in Fig. 5 geschlossen gezeichnete Absperreinrichtung 17' weiterhin geöffnet ist und während des mechanischen Nachverdichtens Druckluft durch den Formstoff 6' fließt.If the pressure plunger 13 'is only slightly removed by the pressure piston 14' from the partition 18 and moved downward at such a pressure potential, a subspace 15b of the pressure space 15 'is created, and the compressed air expanding into the subspace 15b can be accessed via the now accessible Through holes 13d 'suddenly load the molding material 6' and pre-compress in a pulsed manner. The subspace 15b is further enlarged in accordance with FIG. 5 when the mechanical post-compression is initiated by means of the pressure piston 14 ', the course of which does not differ from that of the embodiment in FIGS. 1 to 3; consequently, it is also conceivable here that the shut-off device 17 'shown closed in FIG. 5 is still open and compressed air flows through the molding material 6' during mechanical post-compression.

Aufstellung der BezugszeichenList of reference numbers

1,1'1.1 '
VerdichtungseinrichtungCompression device
11,11'11.11 '
Gehäusecasing
12,12'12.12 '
FormraumMolding space
13,13'13.13 '
DruckstempelPressure stamp
13a,13a'13a, 13a '
DruckflächePrinting area
13b,13b'13b, 13b '
Druckplatteprinting plate
13c,13c'13c, 13c '
Rahmenframe
13d,13d'13d, 13d '
DurchgangsbohrungThrough hole
13e,13e'13e, 13e '
AuslaßOutlet
14,14'14.14 '
DruckkolbenPressure piston
14a,14a'14a, 14a '
KolbenstangePiston rod
15,15'15.15 '
DruckraumPressure room
15a15a
TeilraumSubspace
15b15b
TeilraumSubspace
16,16'16.16 '
DruckluftzuführungCompressed air supply
17,17'17.17 '
AbsperreinrichtungShut-off device
1818th
Trennwandpartition wall
18a18a
DurchbrechungBreakthrough
2,2'2.2 '
FüllrahmenFilling frame
3,3'3.3 '
FormkastenMolded box
4,4'4.4 '
ModellplatteModel plate
41,41'41.41 '
EntlüftungsbohrungVent hole
42,42'42.42 '
SiebSieve
5,5'5.5 '
Modellmodel
6,6'6.6 '
FormstoffMolding material
61,61'61.61 '
Oberflächesurface

Claims (14)

Vorrichtung zur Herstellung von Gießformen, mit einer mit einem Modell versehenen Modellplatte, mit einem auf die Modellplatte aufsetzbaren Formkasten zur Aufnahme eines verdichtbaren Formstoffes, insbesondere eines Formsandes, und mit einer auf den Formkasten aufsetzbaren Verdichtungseinrichtung, mit einer pneumatischen Vorverdichtung und mindestens einem Druckstempel für eine mechanische Nachverdichtung des Formstoffes,
dadurch gekennzeichnet, daß (a) der Druckstempel (13,13') mindestens im Bereich seiner Druckfläche (13a,13a') elastisch verformbar ist,
(b) in der Verdichtungseinrichtung (1,1') oberhalb des Druckstempels (13,13') ein Druckraum (15,15') vorgesehen ist, in dem die Druckluftzuführung (16,16') mündet, und
(c) in dem Druckstempel (13,13') Durchgangsbohrungen (13d,13d') angeordnet sind, welche einen zwischen der Oberfläche (61,61') des Formstoffes (6,6') und dem Druckstempel (13,13') ausgebildeten Formraum (12,12') mit dem Druckraum (15,15') pneumatisch verbinden.Device for the production of casting molds, with a model plate provided with a model, with a mold box that can be placed on the model plate for receiving a compressible molding material, in particular a molding sand, and with a compression device that can be placed on the mold box, with a pneumatic precompression and at least one pressure stamp for one mechanical post-compression of the molding material,
characterized in that (a) the pressure stamp (13, 13 ') is elastically deformable at least in the area of its pressure surface (13a, 13a'),
(b) a pressure chamber (15, 15 ') is provided in the compression device (1, 1') above the pressure ram (13, 13 '), in which the compressed air supply (16, 16') opens, and
(c) through bores (13d, 13d ') are arranged in the pressure stamp (13,13'), which one between the surface (61,61 ') of the molding material (6,6') and the pressure stamp (13,13 ') Connect the formed mold space (12, 12 ') to the pressure space (15, 15') pneumatically. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Durchgangsbohrungen (13d,13d') in dem Druckstempel (13,13') so verteilt sind, daß die Oberfläche (61,61') des Formstoffes (6,6') durchweg dem gleichen Druck aus der Druckluft ausgesetzt ist.Device according to claim 1, characterized in that the through bores (13d, 13d ') in the pressure ram (13, 13') are distributed such that the surface (61, 61 ') of the molding material (6, 6') is the same throughout Air pressure is exposed. Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß in der Modellplatte (4,4') Entlüftungsbohrungen (41,41') für die Druckluft vorgesehen und die Durchgangsbohrungen (13d,13d') nach Anzahl und Querschnitt so bemessen sind, daß während der Vorverdichtung eine gleichförmige Durchströmung des Formstoffes (6,6') erfolgt.Apparatus according to claim 1 or 2, characterized in that vent holes (41, 41 ') are provided in the model plate (4,4') for the compressed air and the through holes (13d, 13d ') are dimensioned in number and cross section such that during the precompression has a uniform flow through the molding material (6, 6 '). Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Durchgangsbohrungen (13d,13d') nach Anzahl und Querschnitt so bemessen sind, daß während einer impulsartigen Druckluft-Einspeisung in den Druckraum (15,15') der dabei dort aufgebaute Luftdruck verzögerungsfrei auch in dem Formraum (12,12') über der Oberfläche (61,61') des Formstoffes (6,6') ansteht.Apparatus according to claim 1 or 2, characterized in that the through bores (13d, 13d ') are dimensioned in terms of number and cross-section so that the air pressure built up there also without delay during a pulsed compressed air feed into the pressure chamber (15, 15') in the molding space (12, 12 ') above the surface (61, 61') of the molding material (6, 6 '). Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, daß in der Modellplatte (4,4') Entlüftungsbohrungen (41,41') für die Druckluft vorgesehen sind.Device according to claim 4, characterized in that ventilation holes (41, 41 ') for the compressed air are provided in the model plate (4,4'). Vorrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß der Druckstempel (13,13') aus einer mindestens partiell elastisch verformbaren Druckplatte (13b,13b') und einem die Druckplatte (13b,13b') außerhalb der Druckfläche (13a,13a') einfassenden, starren Rahmen (13c,13c') zusammengesetzt ist.Device according to one of claims 1 to 5, characterized in that the pressure stamp (13, 13 ') consists of an at least partially elastically deformable pressure plate (13b, 13b') and a pressure plate (13b, 13b ') outside the pressure surface (13a, 13a ') enclosing rigid frame (13c, 13c'). Vorrichtung nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß die Druckplatte (13b,13b') quer zu ihrer Bewegungsrichtung aus mehreren miteinander verbundenen Plattenschichten besteht.Device according to one of claims 1 to 6, characterized in that the pressure plate (13b, 13b ') consists of several interconnected plate layers transversely to their direction of movement. Vorrichtung nach Anspruch 7, dadurch gekennzeichnet, daß die Plattenschichten jeweils aus Werkstoffen unterschiedlicher Elastizität bestehen.Device according to claim 7, characterized in that the plate layers each consist of materials of different elasticity. Vorrichtung nach Anspruch 8, dadurch gekennzeichnet, daß die Elastizität der Plattenschichten in Richtung auf die Druckfläche (13a,13a') hin zunimmt.Device according to claim 8, characterized in that the elasticity of the plate layers increases in the direction of the pressure surface (13a, 13a '). Vorrichtung nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß die Elastizität der Druckplatte (13b,13b'), insbesondere im Bereich ihrer Druckfläche (13a,13a'), so bemessen ist, daß während der mechanischen Nachverdichtung des Formstoffes (6,6') die dabei an dem Formstoff (6,6') anliegenden Auslässe (13e,13e') der Durchgangsbohrungen (13d,13d') durch die auf die Druckplatte (13b,13b') wirkenden Reaktionskräfte kontrahiert werden.Device according to one of claims 1 to 9, characterized in that the elasticity of the pressure plate (13b, 13b '), in particular in the area of its pressure surface (13a, 13a'), is dimensioned such that during the mechanical post-compression of the molding material (6, 6 ') the outlets (13e, 13e') of the through bores (13d, 13d ') which bear against the molding material (6,6') are contracted by the reaction forces acting on the pressure plate (13b, 13b '). Vorrichtung nach einem der Ansprüche 4 bis 10, dadurch gekennzeichnet, daß der Druckraum (15') aus zwei von einer an dem Gehäuse (11') der Verdichtungseinrichtung (1') ortsfesten, quer zu der Bewegungsrichtung des Druckstempels (13') verlaufenden Trennwand (18) voneinander geschiedenen Teilräumen (15a,15b) besteht, die mittels in der Trennwand (18) vorgesehenen Durchbrechungen (18a) pneumatisch miteinander verbindbar sind, und daß die Kolbenstange (14a') durch die Trennwand (18) geführt ist.Device according to one of claims 4 to 10, characterized in that the pressure chamber (15 ') consists of two partition walls which are fixed to the housing (11') of the compression device (1 ') and extend transversely to the direction of movement of the pressure ram (13') (18) separate compartments (15a, 15b), which can be pneumatically connected to one another by means of openings (18a) provided in the partition (18), and that the piston rod (14a ') is guided through the partition (18). Vorrichtung nach Anspruch 11, dadurch gekennzeichnet, daß die Durchbrechungen (18a) in der Trennwand (18) und die Durchgangsbohrungen (13d') quer zu der Bewegungsrichtung des Druckstempels (13') so zueinander versetzt angeordnet sind, daß bei an der Trennwand (18) anliegendem Druckstempel (13') die Teilräume (15a,15b) pneumatisch voneinander getrennt sind.Apparatus according to claim 11, characterized in that the openings (18a) in the partition (18) and the through bores (13d ') are arranged so as to be offset from one another transversely to the direction of movement of the pressure ram (13') such that when the partition (18 ) adjacent plunger (13 ') the subspaces (15a, 15b) are pneumatically separated from each other. Vorrichtung nach einem der Ansprüche 8 bis 12, dadurch gekennzeichnet, daß der Werkstoff für mindestens eine Plattenschicht inkompressibel ist.Device according to one of claims 8 to 12, characterized in that the material is incompressible for at least one plate layer. Vorrichtung nach einem der Ansprüche 1 bis 13, dadurch gekennzeichnet, daß zwischen der Verdichtungseinrichtung (1,1') und dem Formkasten (3,3') ein Füllrahmen (2,2') angeordnet ist.Device according to one of claims 1 to 13, characterized in that a filling frame (2,2 ') is arranged between the compression device (1,1') and the molding box (3,3 ').
EP94120497A 1994-03-22 1994-12-23 Method for the production of moulds Expired - Lifetime EP0673698B1 (en)

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DE4409791 1994-03-22
DE4409791A DE4409791A1 (en) 1994-03-22 1994-03-22 Device for the production of casting molds

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EP0673698B1 EP0673698B1 (en) 1998-12-02

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EP1155761A1 (en) * 2000-05-19 2001-11-21 Josef Mertes Method and apparatus for the densification of moulding materials e.g. foundry sand

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EP0263977A2 (en) * 1986-10-11 1988-04-20 Heinrich Wagner Sinto Maschinenfabrik GmbH Device for compacting moulding sand
EP0319453A2 (en) * 1987-12-01 1989-06-07 Heinrich Wagner Sinto Maschinenfabrik GmbH Method for ramming moulding sand
EP0540454A1 (en) * 1991-10-30 1993-05-05 Agustin Arana Erana Air impact sandbox moulding machine head

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US3041685A (en) * 1961-07-14 1962-07-03 Taccone Corp Diaphragm molding machine

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GB2046644A (en) * 1979-04-11 1980-11-19 Sintokogio Ltd Apparatus for forming a mould
EP0263977A2 (en) * 1986-10-11 1988-04-20 Heinrich Wagner Sinto Maschinenfabrik GmbH Device for compacting moulding sand
EP0319453A2 (en) * 1987-12-01 1989-06-07 Heinrich Wagner Sinto Maschinenfabrik GmbH Method for ramming moulding sand
EP0540454A1 (en) * 1991-10-30 1993-05-05 Agustin Arana Erana Air impact sandbox moulding machine head

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001051235A1 (en) * 2000-01-14 2001-07-19 Sintokogio, Ltd. Molding method and system with a molding apparatus
EP1155761A1 (en) * 2000-05-19 2001-11-21 Josef Mertes Method and apparatus for the densification of moulding materials e.g. foundry sand

Also Published As

Publication number Publication date
DE4409791A1 (en) 1995-09-28
EP0673698B1 (en) 1998-12-02
ES2124359T3 (en) 1999-02-01
DE59407392D1 (en) 1999-01-14

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