EP0170765A1 - Device for compacting foundry moulding material - Google Patents

Device for compacting foundry moulding material Download PDF

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Publication number
EP0170765A1
EP0170765A1 EP85102322A EP85102322A EP0170765A1 EP 0170765 A1 EP0170765 A1 EP 0170765A1 EP 85102322 A EP85102322 A EP 85102322A EP 85102322 A EP85102322 A EP 85102322A EP 0170765 A1 EP0170765 A1 EP 0170765A1
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EP
European Patent Office
Prior art keywords
molding
closure member
valve
pressure vessel
opening
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EP85102322A
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German (de)
French (fr)
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EP0170765B1 (en
Inventor
Alfons Ing. grad. Köbel
Norbert Ing. Grad. Damm
Werner Geiger
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Badische Maschinenfabrik GmbH
BMD Badische Maschinenfabrik Durlach GmbH
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Badische Maschinenfabrik GmbH
BMD Badische Maschinenfabrik Durlach 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

Definitions

  • the invention relates to a device for compressing foundry molding material, which is loosely heaped up in a closed molding space above a model, by means of compressed gas acting on the molding material surface, which suddenly emerges from a pressure vessel of high pressure via a valve between the latter and the molding space in the latter is relaxed, the molding space being formed from a molding box with a filling frame and a model plate representing the bottom thereof, and the valve has a closure member which releases the opening cross section in a few milliseconds.
  • a large number of mechanical, pneumatic and combined compression methods are known for the compression of foundry molding material, only the pneumatic methods being of interest in connection with the invention. These can essentially be divided into two categories. In the first category, the molding material is placed under gas pressure in an anteroom after opening a valve, it is blown or shot into the mold space together with the air. In any case, this process requires mechanical re-pressing of the molding material in the molding box with significant pressing forces (e.g. DE-AS 28 44 464). In the other category, the molding material is loosely poured onto the model and then suddenly subjected to compressed air from the back of the mold (e.g. DE-AS 28 44 464, DE-AS 1 961 234).
  • the first variant (DE-AS 28 44 464)
  • compressed air up to 7 bar is blown once or several times over a period of between 0.2 and 1 s through openings in a hollow end plate of the molding space, the air flowing through the molding sand should flow out through openings in the model plate.
  • Mechanical repressing is also necessary here, on the one hand to compress the back of the mold, and on the other hand to squeeze out the residual air that is still present in the molding material due to the fluidization effect, the squeezing also being to be supported by a vacuum. This process does not achieve a noticeable reduction in design effort compared to the closing and blowing processes.
  • a molding machine is described (DE-AS 1 961 234), in which a pressure vessel is arranged above the closed molding box or a filling frame arranged above it, which can be connected to the molding space via a mechanically moved valve for mold boxes of customary size, a pre-pressure of 100 bar is proposed in order to achieve a satisfactory compression there after relaxation in the mold space.
  • a high pressure easily leads to irregularities in the surface of the molding material when the compressed gas impinges on the back of the mold, as well as to a considerable design effort in order to generate such high pressures and to achieve the necessary compressive strength in the molding space.
  • the valve of the known device is a poppet valve which is opened by means of a combined pneumatic-mechanical auxiliary drive against the pressure in the pressure vessel and closes an opening of a relatively small cross section between the pressure vessel and the molding box.
  • a distributor cone is provided under the valve opening and underneath there is a perforated floor that extends over the entire mold area or, in another variant, an adjustable slot floor (DE-OS 2 151 949).
  • the invention has for its object to provide a device by means of which a uniform and sufficiently high compression with a uniform molding surface is possible with comparatively little design effort.
  • This object is achieved according to the invention in that the pressure vessel has an opening approximately corresponding to the outline of the molding box, against the edge of which the molding box can be pressed in a sealing manner with the filling frame and with which the closure member cooperates.
  • the opening cross-section can have any size, maximum the size of the molding box or filling frame cross-section, so that the compressed gas can pass through with the greatest possible speed with the greatest possible mass throughput, so that the molding material is compressed optimally and uniformly.
  • valve has a closure member which releases the opening cross-section mainly under the effect of the pressure in the pressure vessel.
  • the high potential energy of the compressed gas is thus used to open the valve, in other words: the driving force for the closure member is obtained directly from the compressed gas, which ensures the fastest possible acceleration of the closure member. No separate drive for the closure member is necessary. Only for the return of the closure member, which takes place in the depressurized state and therefore does not require large forces, is a relatively small one Driving force also to keep the closure member in the closed position of the valve.
  • Embodiments of this embodiment are characterized in claims 3 and 4.
  • a fixed grate is inserted into the opening of the pressure vessel and a sliding grate is arranged above it, which is under the action of a spring preload acting in its plane and is held in the closed position by a lock, after unlocking it under the spring preload into the open position is movable.
  • the drive of the closure member for opening is decoupled from the parts of the closure member which provide the valve closure. Due to the rust-like design of the closure member, the largest possible opening cross-section can be released in the shortest possible time with the smallest opening stroke which must correspond to the grate bar width, which in turn ensures rapid gas transfer with a high mass throughput. At the same time, the rust-like design of the opening ensures a uniform, full-surface impact of the gas pressure front on the molding material surface.
  • a mold box 2 sits on a model plate 1 with the model (not shown) and a filling frame 3 on this. These parts form the mold space.
  • a pressure vessel 4 for holding pressurized gas up to 20 bar is arranged above the molding space and is fed via a nozzle 5 from a pressure accumulator or - at low admission pressure - from the compressed air network.
  • the pressure vessel has an opening which is arranged centrally and whose inside width in the exemplary embodiment according to FIG. 1 corresponds approximately to the free horizontal cross section of the filling frame 3 or the molding box 2.
  • the unit consisting of model plate 1, molding box 2 and filling frame 3 can be pressed against the pressure vessel 4 with the opening 6 from below.
  • the opening 6 of the pressure vessel is assigned a closure member, designated overall by 8.
  • the closure member 9 is formed by two flaps 91 which are inclined towards one another above the opening 6 and in the direction thereof.
  • the flaps 91 are articulated on their mutually facing upper edges in bearings 92, while on their lower edges they are held in the closed position by means of a beam 93 of a holder 94. Sealing takes place on a circumferential sealing seat 95.
  • a plunger 97 which is in a housing 96 of the holder 94 is guided and actuated by a cam 98, the flaps are released and accelerated suddenly under the action of the compressed gas in the pressure vessel 4 into the open position shown in dashed lines. There their kinetic energy is destroyed by attenuators 99.
  • the closing movement can be carried out by conventional means such as springs, pneumatic cylinders or the like, while the locking in the closed position is done by springs 100.
  • the flaps 91 consist, for example, of a frame made of high-strength light metal alloy, which is connected to a plastic sheet, e.g. B. made of polyethylene (PE).
  • the opening 6 of the pressure vessel 4 is penetrated by the strips 101 of a fixed grate 102.
  • a sliding grate 103 is arranged, the strips 104 on the side facing the grate 102 with a sealing material 105, for. B. low-pressure PE are provided.
  • the strips 101 of the fixed grate 102 are additionally supported by ribs 106 against the static load of the compressed gas.
  • the sliding grate 103 is under a spring force 107 and is locked in the closed position shown in FIG. 2 by a locking lever 108.
  • the lock By pivoting the lever up, the lock is released and the stored spring force is suddenly released, so that the sliding grate is accelerated into its open position in which the strips 101 and 104 of the two gratings 102, 103 lie one above the other. In this position, the sliding grate 104 is braked by damping elements, not shown.
  • the sliding grate can be reset in a conventional manner until the locking lever 108 can be moved back into the locked position.

Abstract

Eine Vorrichtung zum Verdichten von Gießerei-Formstoff, der in einem geschlossenen Formraum über einem Modell lose aufgeschüttet und mittels auf die Formstoff-Oberfläche wirkenden Druckgases verdichtet wird, weist einen Druckbehälter (4) hohen Drucks und ein Ventil (8) zwischen diesem und dem Formraum auf, wobei der Formraum aus einem Formkasten (2) mit Füllrahmen (3) und einer dessen Boden darstellenden Modellplatte (1) mit dem Modell gebildet ist und das Ventil (8) ein Verschlußorgan (9) aufweist, das den Öffnungsquerschnitt des Ventils in wenigen Millisekunden freigibt. Eine kompakte Bauweise mit schnellem und großem Gasmassendurchsatz wird dadurch erhalten, daß der Druckbehälter (4) eine etwa dem Umriß des Formkastens (2) entsprechende Öffnung (6) aufweist, gegen deren Rand (7) der Formkasten (2) mit dem Füllrahmen (3) dichtend anpreßbar ist und mit der das Verschlußorgan (9) zusammenwirkt, das seinerseits vorwiegend unter Wirkung des Drucks im Druckbehälter (4) den Öffnungsquerschnitt freigibt.A device for compressing foundry molding material, which is loosely heaped over a model in a closed molding space and compressed by means of compressed gas acting on the molding material surface, has a pressure vessel (4) of high pressure and a valve (8) between it and the molding space on, wherein the molding space is formed from a molding box (2) with a filling frame (3) and a model plate (1) representing the bottom thereof, and the valve (8) has a closure member (9) which has the opening cross section of the valve in a few Releases milliseconds. A compact design with a fast and large gas mass throughput is obtained in that the pressure vessel (4) has an opening (6) corresponding approximately to the outline of the molding box (2), against the edge (7) of which the molding box (2) with the filling frame (3 ) can be pressed in a sealing manner and with which the closure member (9) interacts, which in turn releases the opening cross section predominantly under the effect of the pressure in the pressure vessel (4).

Description

Die Erfindung betrifft eine Vorrichtung zum Verdichten von Gießerei-Formstoff, der in einem geschlossenen Formraum über einem Modell lose aufgeschüttet ist, mittels auf die Formstoff-Oberfläche wirkendem Druckgas, das aus einem Druckbehälter hohen Drucks über ein Ventil zwischen diesem und dem Formraum in letzteren schlagartig entspannt wird, wobei der Formraum aus einem Formkasten mit Füllrahmen und einer dessen Boden darstellenden Modellplatte mit dem Modell gebildet ist und das Ventil ein Verschlußorgan aufweist, das den öffnungsquerschnitt in wenigen Millisekunden freigibt.The invention relates to a device for compressing foundry molding material, which is loosely heaped up in a closed molding space above a model, by means of compressed gas acting on the molding material surface, which suddenly emerges from a pressure vessel of high pressure via a valve between the latter and the molding space in the latter is relaxed, the molding space being formed from a molding box with a filling frame and a model plate representing the bottom thereof, and the valve has a closure member which releases the opening cross section in a few milliseconds.

Für die Verdichtung von Gießerei-Formstoff sind eine Vielzahl von Verdichtungsverfahren mechanischer, pneumatischer und kombinierter Art bekannt, wobei in Zusammenhang mit der Erfindung nur die pneumatischen Verfahren interessieren. Diese lassen sich im wesentlichen in zwei Kategorien unterscheiden. Bei der ersten Kategorie wird der Formstoff in einem Vorraum unter Gasdruck gesetzt und nach öffnen eines Ventils zusammen mit der Luft in den Formraum eingeblasen oder eingeschossen. Dieses Verfahren erfordert in jedem Fall ein mechanisches Nachpressen des Formstoffs im Formkasten mit nennenswerten Preßkräften (z. B. DE-AS 28 44 464). Bei der anderen Kategorie wird der Formstoff lose auf das Modell aufgeschüttet und anschließend vom Formrücken her mit Druckluft schlagartig beaufschlagt (z. B. DE-AS 28 44 464, DE-AS 1 961 234).A large number of mechanical, pneumatic and combined compression methods are known for the compression of foundry molding material, only the pneumatic methods being of interest in connection with the invention. These can essentially be divided into two categories. In the first category, the molding material is placed under gas pressure in an anteroom after opening a valve, it is blown or shot into the mold space together with the air. In any case, this process requires mechanical re-pressing of the molding material in the molding box with significant pressing forces (e.g. DE-AS 28 44 464). In the other category, the molding material is loosely poured onto the model and then suddenly subjected to compressed air from the back of the mold (e.g. DE-AS 28 44 464, DE-AS 1 961 234).

Dabei sind im wesentlichen zwei Varianten bekannt. Bei der ersten Variante (DE-AS 28 44 464) wird über öffnungen in einer hohlen Abschlußplatte des Formraums betriebsintern vorhandene Preßluft bis zu 7 bar über eine Zeitdauer zwischen 0,2 und 1 s einmal oder mehrmals eingeblasen, wobei die durch den Formsand strömende Luft über Öffnungen in die Modellplatte abströmen soll. Auch hier ist ein mechanisches Nachpressen notwendig, um einerseits den Formrücken zu verdichten, andererseits die aufgrund des Fluidisierungseffektes in dem Formstoff noch vorhandene Restluft abzupressen, wobei das Abpressen zusätzlich durch Unterdruck unterstützt werden soll. Eine nennenswerte Minderung an konstruktivem Aufwand gegenüber den Schließ- und Blasverfahren wird mit diesem Verfahren nicht erreicht.Essentially two variants are known. In the first variant (DE-AS 28 44 464), compressed air up to 7 bar is blown once or several times over a period of between 0.2 and 1 s through openings in a hollow end plate of the molding space, the air flowing through the molding sand should flow out through openings in the model plate. Mechanical repressing is also necessary here, on the one hand to compress the back of the mold, and on the other hand to squeeze out the residual air that is still present in the molding material due to the fluidization effect, the squeezing also being to be supported by a vacuum. This process does not achieve a noticeable reduction in design effort compared to the closing and blowing processes.

Bei der anderen Verfahrensvariante (DE-AS 1 961 234)wird im Hochdruckbereich gearbeitet, was hier heißen soll, daß der Druck im Vorraum nennenswert über dem Betriebsdruck eines üblichen innerbetrieblichen Druckluftnetzes von bis zu 7 bar liegt. Im bekannten Fall wird ein Vordruck zwischen 20 und 100 bar vorgeschlagen. Dieser Druck soll dann in den Formraum innerhalb maximal 0,15 s entspannt werden. Dabei soll auf das sonst übliche Nachpressen verzichtet werden können. Als weitere Voraussetzung für die Wirksamkeit dieses Verfahrens wird ein bestimmtes Verhältnis von Gasdurchsatz einerseits und Formstoffmasse andererseits gefordert, wobei dieses Verhältnis zwischen 5 : 1 und 40 : 1 betragen soll, womit zugleich eine Abhängigkeit zwischen Gasdurchsatz und Formkastengröße gegeben ist. Zur Durchführung des Verfahrens ist eine Formmaschine beschrieben (DE-AS 1 961 234), bei der oberhalb des geschlossenen Formkastens bzw. einem darüber angeordneten Füllrahmen ein Druckbehälter angeordnet ist, der über ein mechanisch bewegtes Ventil mit dem Formraum verbindbar ist.Bei vertretbarer Baugröße wird für Formkästen üblicher Größe ein Vordruck von 100 bar vorgeschlagen, um nach der Entspannung in den Formraum dort eine befriedigende Verdichtung zu erreichen. Ein derart hoher Druck führt beim Aufprallen des Druckgases auf den Formrücken leicht zu Unregelmäßigkeiten in der Formstoff-Oberfläche, wie auch zu einem erheblichen konstruktiven Aufwand, um solche hohen Drücke zu erzeugen und die notwendige Druckfestigkeit im Formraum zu erreichen. Das Ventil der bekannten Vorrichtung ist ein Tellerventil, das mittels eines kombinierten pneumatischmechanischen Hilfsantriebs gegen den Druck im Druckbehälter geöffnet wird und eine öffnung von verhältnismäßig kleinem Querschnitt zwischen Druckbehälter und Formkasten verschließt. Um das Druckgas nicht strahlenförmig auf die Formstoff-Oberfläche aufprallen zu lassen, ist weiterhin unter der Ventilöffnung ein Verteilerkonus und darunter ein sich über die gesamte Formraumfläche erstreckender Lochboden oder in einer anderen Variante ein einstellbarer Schlitzboden (DE-OS 2 151 949) vorgesehen. Mit dieser Vorrichtung läßt sich der bei diesem Gasdruck-Formverfahren geforderte hohe Druckgradient von beispielsweise mehr als 300 bar/s im Formraum nicht erreichen, da das Ventil gegen den Druck geöffnet werden muß und der Öffnu_ngsquerschnitt des Ventils zu klein ist, um das Druckgas schlagartig überströmen zu lassen, Hinzu kommt der Strömungswiderstand aus dem Ventil nachgeschalteten Verteilerkonus und des Lochbodens, die zu einer weiteren Verzögerung führen. Aufbauend auf diesen Stand der Technik liegt der Erfindung die Aufgabe zugrunde, eine Vorrichtung zu schaffen, mit deren Hilfe eine gleichmäßig und ausreichend hohe Verdichtung bei gleichmäßiger Formstoff-Oberfläche mit vergleichsweise geringem konstruktiven Aufwand möglich ist. Diese Aufgabe wird gemäß der Erfindung dadurch gelöst, daß der Druckbehälter eine etwa dem Umriß des Formkastens entsprechende Öffnung aufweist, gegen deren Rand der Formkasten mit dem Füllrahmen dichtend anpreßbar ist und mit der das Verschlußorgan zusammenwirkt.In the other process variant (DE-AS 1 961 234) work is carried out in the high pressure range, which means that the pressure in the anteroom is appreciably above the operating pressure of a conventional internal compressed air network of up to 7 bar. In the known case, a pre-pressure between 20 and 100 bar is proposed. This pressure should then be released into the mold space within a maximum of 0.15 s. It should be possible to dispense with the usual re-pressing. As a further prerequisite for the effectiveness of this method, a certain one Ratio of gas throughput on the one hand and molding material mass on the other hand required, this ratio should be between 5: 1 and 40: 1, which also gives a dependency between gas throughput and mold box size. To carry out the method, a molding machine is described (DE-AS 1 961 234), in which a pressure vessel is arranged above the closed molding box or a filling frame arranged above it, which can be connected to the molding space via a mechanically moved valve for mold boxes of customary size, a pre-pressure of 100 bar is proposed in order to achieve a satisfactory compression there after relaxation in the mold space. Such a high pressure easily leads to irregularities in the surface of the molding material when the compressed gas impinges on the back of the mold, as well as to a considerable design effort in order to generate such high pressures and to achieve the necessary compressive strength in the molding space. The valve of the known device is a poppet valve which is opened by means of a combined pneumatic-mechanical auxiliary drive against the pressure in the pressure vessel and closes an opening of a relatively small cross section between the pressure vessel and the molding box. In order to prevent the compressed gas from striking the surface of the molding material in a radial manner, a distributor cone is provided under the valve opening and underneath there is a perforated floor that extends over the entire mold area or, in another variant, an adjustable slot floor (DE-OS 2 151 949). With this device, the high pressure gradient of, for example, more than 300 bar / s in the molding space required in this gas pressure molding process cannot be achieved, since the valve must be opened against the pressure and the opening cross section of the valve is too small to suddenly flow over the compressed gas to let, in addition comes the flow resistance downstream of the distributor cone and the perforated base, which lead to a further delay. Based on this prior art, the invention has for its object to provide a device by means of which a uniform and sufficiently high compression with a uniform molding surface is possible with comparatively little design effort. This object is achieved according to the invention in that the pressure vessel has an opening approximately corresponding to the outline of the molding box, against the edge of which the molding box can be pressed in a sealing manner with the filling frame and with which the closure member cooperates.

Mit dieser Ausbildung entsteht eine kompakte Baueinheit, bei der das Druckgas bei geöffnetem Verschlußorgan über die Öffnung direkt und vollflächig auf die Formstoff-Oberfläche entspannt wird. Der Öffnungsquerschnitt kann jede beliebige Größe, maximal die Größe des Formkasten- bzw. Füllrahmenquerschnitts aufweisen, so daß das Druckgas mit größtmöglicher Geschwindigkeit bei größtmöglichem Massendurchsatz hindurchtreten kann, so daß der Formstoff optimal und gleichmäßig verdichtet wird.With this design, a compact structural unit is created in which the compressed gas is released directly and over the entire surface of the molding material surface when the closure member is open. The opening cross-section can have any size, maximum the size of the molding box or filling frame cross-section, so that the compressed gas can pass through with the greatest possible speed with the greatest possible mass throughput, so that the molding material is compressed optimally and uniformly.

In einer bevorzugten Ausführung dieser Vorrichtung ist vorgesehen, daß das Ventil ein Verschlußorgan aufweist, das vorwiegend unter Wirkung des Drucks im Druckbehälter den öffnungsquerschnitt freigibt.In a preferred embodiment of this device it is provided that the valve has a closure member which releases the opening cross-section mainly under the effect of the pressure in the pressure vessel.

Erfindungsgemäß wird also die hohe potentielle Energie des Druckgases ausgenutzt, um das Ventil zu öffnen, mit anderen Worten: Die Antriebskraft für das Verschlußorgan wird unmittelbar aus dem Druckgas bezogen, das für eine schnellstmögliche Beschleunigung des Verschlußorgans sorgt. Es ist kein gesonderter Antrieb für das Verschlußorgan notwendig. Lediglich für die Rückführung des Verschlußorgans, die im drucklosen Zustand erfolgt und deshalb keine großen Kräfte erfordert, ist eine relativ geringe Antriebskraft aufzubringen ebenso für das Halten des Verschlußorgans in der Schließlage des Ventils.According to the invention, the high potential energy of the compressed gas is thus used to open the valve, in other words: the driving force for the closure member is obtained directly from the compressed gas, which ensures the fastest possible acceleration of the closure member. No separate drive for the closure member is necessary. Only for the return of the closure member, which takes place in the depressurized state and therefore does not require large forces, is a relatively small one Driving force also to keep the closure member in the closed position of the valve.

Ausgestaltungen dieser Ausführungsform sind in den Patentansprüchen 3 und 4 gekennzeichnet. Gemäß einer weiteren Ausführungsform ist in die Öffnung des Druckbehälters ein feststehender Rost eingesetzt und darüber ein Schieberost angeordnet, der unter Wirkung einer in seiner Ebene wirkenden Federvorspannung steht und durch eine Verriegelung in der Schließlage gehalten ist, nach deren Entriegelung er unter der Federvorspannung in die Öffnungslage bewegbar ist.Embodiments of this embodiment are characterized in claims 3 and 4. According to a further embodiment, a fixed grate is inserted into the opening of the pressure vessel and a sliding grate is arranged above it, which is under the action of a spring preload acting in its plane and is held in the closed position by a lock, after unlocking it under the spring preload into the open position is movable.

Auch bei dieser Ausführungsform ist der Antrieb des Verschlußorgans für das Öffnen von den dem Ventilverschluß besorgenden Teilen des Verschlußorgans abgekoppelt. Durch die rostartige Ausbildung des Verschlußorgans läßt sich bei geringstem öffnungshub die der Roststabbreite entsprechen muß, in kürzester Zeit ein größtmöglicher Öffnungsquerschnitt freigeben, was wiederum für einen schnellen Gasübertritt bei hohem Massendurchsatz sorgt. Zugleich wird durch die rostartige Ausbildung der Öffnung ein gleichmäßiges, vollflächiges Au ftreffen der Gasdruckfront auf die Formstoffoberfläche gewährleistet.In this embodiment too, the drive of the closure member for opening is decoupled from the parts of the closure member which provide the valve closure. Due to the rust-like design of the closure member, the largest possible opening cross-section can be released in the shortest possible time with the smallest opening stroke which must correspond to the grate bar width, which in turn ensures rapid gas transfer with a high mass throughput. At the same time, the rust-like design of the opening ensures a uniform, full-surface impact of the gas pressure front on the molding material surface.

Nachstehend ist die Erfindung anhand zweier in der Zeichnung dargestellter Ausführungsbeispiele beschrieben. In der Zeichnung zeigen:

  • Fig. 1 eine schematische teilweise geschnittene Ansicht einer Ausführungsform der Vorrichtung und
  • Fig. 2 eine der Fig. 1 ähnliche Ansicht einer zweiten Ausführungsform.
The invention is described below with reference to two exemplary embodiments shown in the drawing. The drawing shows:
  • Fig. 1 is a schematic partially sectioned view of an embodiment of the device and
  • Fig. 2 is a view similar to Fig. 1 of a second embodiment.

In der Zeichnung sind nur die zum Verständnis der Erfindung notwendigen Teile einer Verdichtungsvorrichtung wiedergegeben. Es sind insbesondere nicht gezeigt der Maschinenständer, die Einrichtungen zum Heben und Senken von Formkasten und Füllrahmen sowie gegebenenfalls zum Ausstoßen der fertigen Form aus dem Formkasten. Ebensowenig sind die Einrichtungen zum Heranbringen des Modells und zum Einfüllen des Formsandes wiedergegeben, da alle vorgenannten Bauteile im Gießerei-Maschinenbau bekannt sind.In the drawing are only those for understanding the invention necessary parts of a compression device reproduced. In particular, the machine stand, the devices for lifting and lowering the molding box and filling frame and, if appropriate, for ejecting the finished mold from the molding box are not shown. The facilities for bringing up the model and for filling in the molding sand are also not shown, since all of the above-mentioned components are known in foundry mechanical engineering.

Auf einer Modellplatte 1 mit dem nicht gezeigten Modell sitzt ein Formkasten 2 und auf diesem ein Füllrahmen 3. Diese Teile bilden den Formraum. Oberhalb des Formraums ist ein Druckbehälter 4 zur Aufnahme von Druckgas bis zu 20 bar angeordnet, der über einen Stutzen 5 aus einem Druckspeicher oder - bei niedrigem Vordruck - aus dem Druckluftnetz gespeist wird.A mold box 2 sits on a model plate 1 with the model (not shown) and a filling frame 3 on this. These parts form the mold space. A pressure vessel 4 for holding pressurized gas up to 20 bar is arranged above the molding space and is fed via a nozzle 5 from a pressure accumulator or - at low admission pressure - from the compressed air network.

Der Druckbehälter weist eine Öffnung auf, die zentrisch angeordnet ist und deren lichte Weite beim Ausführungsbeispiel gemäß Fig. 1 etwa dem freien horizontalen Querschnitt des Füllrahmens 3 bzw. des Formkastens 2 entspricht. Gegen den Druckbehälter 4 mit der Öffnung 6 ist die aus Modellplatte 1, Formkasten 2 und Füllrahmen 3 bestehende Einheit von unten her anpreßbar. Der Öffnung 6 des Druckbehälters ist ein insgesamt mit 8 bezeichnetes Verschlußorgan zugeordnet.The pressure vessel has an opening which is arranged centrally and whose inside width in the exemplary embodiment according to FIG. 1 corresponds approximately to the free horizontal cross section of the filling frame 3 or the molding box 2. The unit consisting of model plate 1, molding box 2 and filling frame 3 can be pressed against the pressure vessel 4 with the opening 6 from below. The opening 6 of the pressure vessel is assigned a closure member, designated overall by 8.

Das Verschlußorgan 9 wird von zwei Klappen 91 gebildet, die oberhalb der Öffnung 6 und in Richtung auf diese zueinander geneigt sind. Die Klappen 91 sind an ihren einander abgekehrten oberen Kanten in Lagern 92 angelenkt, während sie an ihren unteren Kanten mittels eines Balkens 93 einer Halterung 94 in der Schließlage gehalten sind. Die Abdichtung erfolgt an einem umlaufenden Dichtsitz 95. Durch Absenken des Balkens 93 mittels eines Stößels 97, der in einem Gehäuse 96 der Halterung 94 geführt ist und von einer Kurvenscheibe 98 betätigt wird, werden die Klappen freigegeben und unter Wirkung des Druckgases im Druckbehälter 4 schlagartig in die gestrichelt gezeigte Öffnungslage beschleunigt. Dort wird ihre kinetische Energie durch Dämpfungsglieder 99 vernichtet. Die Schließbewegung kann durch herkömmliche Mittel, wie Federn, pneumatische Zylinder od. dgl. erfolgen, während die Verriegelung in der Schließlage durch Federn 100 geschieht. Um die zu beschleunigende Masse so gering als möglich zu halten, bestehen die Klappen 91 beispielsweise aus einem Rahmen aus hochfester Leichmetalllegierung, der mit einer Kunststoffbahn, z. B. aus Polyethylen (PE), bespannt ist.The closure member 9 is formed by two flaps 91 which are inclined towards one another above the opening 6 and in the direction thereof. The flaps 91 are articulated on their mutually facing upper edges in bearings 92, while on their lower edges they are held in the closed position by means of a beam 93 of a holder 94. Sealing takes place on a circumferential sealing seat 95. By lowering the beam 93 by means of a plunger 97 which is in a housing 96 of the holder 94 is guided and actuated by a cam 98, the flaps are released and accelerated suddenly under the action of the compressed gas in the pressure vessel 4 into the open position shown in dashed lines. There their kinetic energy is destroyed by attenuators 99. The closing movement can be carried out by conventional means such as springs, pneumatic cylinders or the like, while the locking in the closed position is done by springs 100. In order to keep the mass to be accelerated as low as possible, the flaps 91 consist, for example, of a frame made of high-strength light metal alloy, which is connected to a plastic sheet, e.g. B. made of polyethylene (PE).

In der Ausführungsform gemäß Fig. 2 ist die Öffnung 6 des Druckbehälters 4 von den Leisten 101 eines feststehenden Rostes 102 durchsetzt. Oberhalb des Rostens 102 ist ein Schieberost 103 angeordnet, dessen Leisten 104 an der dem Rost 102 zugekehrten Seite mit einem Dichtwerkstoff 105, z. B. Niederdruck-PE,versehen sind. Die Leisten 101 des feststehenden Rostes 102 sind gegen die statische Last des Druckgases zusätzlich durch Rippen 106 unterstützt. Der Schieberost 103 steht unter einer Federkraft 107 und wird in der in Fig. 2 gezeigten Schließlage durch einen Verriegelungshebel 108 gesperrt. Durch Hochschwenken des Hebels wird die Verriegelung aufgehoben und die gespeicherte Federkraft schlagartig freigegeben, so daß der Schieberost in seine öffnungslage beschleunigt wird, in der die Leisten 101 und 104 der beiden Roste 102, 103 übereinander liegen. In dieser Stellung wird der Schieberost 104 durch nicht gezeigte Dämpfungsglieder abgebremst. Die Rückstellung des Schieberostes kann in herkömmlicher Weise erfolgen, bis sich der Verriegelungshebel 108 wieder in die Sperrlage bewegen läßt.In the embodiment according to FIG. 2, the opening 6 of the pressure vessel 4 is penetrated by the strips 101 of a fixed grate 102. Above the grate 102, a sliding grate 103 is arranged, the strips 104 on the side facing the grate 102 with a sealing material 105, for. B. low-pressure PE are provided. The strips 101 of the fixed grate 102 are additionally supported by ribs 106 against the static load of the compressed gas. The sliding grate 103 is under a spring force 107 and is locked in the closed position shown in FIG. 2 by a locking lever 108. By pivoting the lever up, the lock is released and the stored spring force is suddenly released, so that the sliding grate is accelerated into its open position in which the strips 101 and 104 of the two gratings 102, 103 lie one above the other. In this position, the sliding grate 104 is braked by damping elements, not shown. The sliding grate can be reset in a conventional manner until the locking lever 108 can be moved back into the locked position.

Claims (7)

1. Vorrichtung zum Verdichten von Gießerei-Formstoff, der in einem geschlossenen Formraum über einem Modell lose aufgeschüttet ist, mittels auf die Formstoff-Oberfläche wirkendem Druckgas, das aus einem Druckbehälter hohen Drucks über ein Ventil zwischen diesem und dem Formraum in letzteren schlagartig entspannt wird, wobei der Formraum aus einem Formkasten mit Füllrahmen und einer dessen Boden darstellenden Modellplatte mit dem Modell gebildet ist und das Ventil ein Verschlußorgan aufweist, das den öffnungsquerschnitt des Ventils in wenigen Millisekunden freigibt, dadurch gekennzeichnet, daß der Druckbehälter (4) eine etwa dem Umriß des Formkastens (2) entsprechende Öffnung (6) aufweist, gegen deren Rand (7) der Formkasten (2) mit dem Füllrahmen (3) dichtend anpreßbar ist und mit der das Verschlußorgan (9) zusammenwirkt.1. Device for compressing foundry molding material, which is loosely heaped over a model in a closed molding space, by means of compressed gas acting on the molding material surface, which is suddenly expanded from a pressure vessel of high pressure via a valve between the latter and the molding space in the latter , wherein the molding space is formed from a molding box with a filling frame and a model plate representing the bottom thereof, and the valve has a closure member which releases the opening cross section of the valve in a few milliseconds, characterized in that the pressure vessel (4) has an approximately outline of the molding box (2) has a corresponding opening (6), against the edge (7) of which the molding box (2) can be pressed in a sealing manner with the filling frame (3) and with which the closure member (9) cooperates. 2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß das Ventil (8) ein Verschlußorgan (9) aufweist, das vorwiegend unter Wirkung des Drucks im Druckbehälter (4) den Öffnungsquerschnitt freigibt.2. Device according to claim 1, characterized in that the valve (8) has a closure member (9) which releases the opening cross-section mainly under the effect of the pressure in the pressure vessel (4). 3. Vorrichtung nach einem der Ansprüche 1 oder 2, dadurch gekennzeichnet, daß das Verschlußorgan (9) aus zwei Klappen (91) gebildet ist, die gegenüber der Ebene der Öffnung (6) unter einem gleichen Winkel geneigt, an den einander zugekehrten unteren Kanten durch eine gemeinsame lösbare Halterung (94) in Schließlage gehalten und an den einander abgekehrten oberen Kanten angelenkt sind.3. Device according to one of claims 1 or 2, characterized in that the closure member (9) is formed from two flaps (91) which is inclined at an equal angle to the plane of the opening (6) on the mutually facing lower edges are held in the closed position by a common releasable holder (94) and are articulated on the mutually facing upper edges. 4. Vorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß die Halterung (94) aus einem heb- und senkbaren, die unteren Kanten der Klappen (91) in der Schließlage unterfangenden Balken (93) besteht.4. The device according to claim 3, characterized in that the holder (94) consists of a raised and lowered, the lower edges of the flaps (91) in the closed position undercutting beams (93). 5. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet,daß in die Öffnung (6) ein feststehender Rost (102) eingesetzt und darüber ein Schiebrost (103) angeordnet ist, der unter Wirkung einer in seiner Ebene wirkenden Federvorspannung (107) steht und durch eine Verriegelung (108) in der Schließlage gehalten ist, nach deren Entriegelung er unter der Federvorspannung in die Öffnungslage bewegbar ist.5. The device according to claim 1, characterized in that in the opening (6) a fixed grate (102) is inserted and above a sliding grate (103) is arranged, which is under the action of a spring bias acting in its plane (107) and by a Lock (108) is held in the closed position, after unlocking it can be moved into the open position under the spring preload. 6. Vorrichtung nach Anspruch 5, dadurch gekennzeichnet, daß der Schieberost (103) an der dem feststehenden Rost (102) zugekehrten Seite Leisten (105) aus einem verschleißfesten, dichtenden Werkstoff aufweist.6. The device according to claim 5, characterized in that the sliding grate (103) on the fixed grate (102) side facing strips (105) made of a wear-resistant, sealing material. 7. Vorrichtung nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß das Verschlußorgan (9) und die sie haltenden Teile zu einer Baueinheit zusammengefaßt sind, die an dem Druckbehälter (4) auswechselbar angebracht ist.7. Device according to one of claims 1 to 6, characterized in that the closure member (9) and the parts holding them are combined to form a structural unit which is interchangeably attached to the pressure vessel (4).
EP85102322A 1981-12-28 1982-11-27 Device for compacting foundry moulding material Expired EP0170765B1 (en)

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DE3151645 1981-12-28
DE3151645 1981-12-28
DE3206208 1982-02-20
DE3206208 1982-02-20

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DE3518980A1 (en) * 1985-05-25 1986-11-27 BMD Badische Maschinenfabrik Durlach GmbH, 7500 Karlsruhe DEVICE FOR COMPRESSING FOUNDRY MOLD BY PRESSURE GAS
ES2006861A6 (en) * 1988-03-21 1989-05-16 Lopez Foronda Fernandez Vicent Improvements introduced in airvessels for molding by expansive waves.
ES2011685A6 (en) * 1988-10-21 1990-02-01 Lopez Foronda Fernandez Vicent Improvements introduced in air impact molding machines.
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CH686412A5 (en) * 1992-03-10 1996-03-29 Fischer Georg Giessereianlagen A method of compacting molding sand for molds.
DK0849017T3 (en) * 1996-12-17 2002-01-21 Loramendi Sa Improved air stroke or impulse sand mold compressor
CN105170917B (en) * 2015-09-30 2017-11-28 共享铸钢有限公司 The flash mould frock and its flash mould method of a kind of heavy duty disc class casting

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Also Published As

Publication number Publication date
DD203693A5 (en) 1983-11-02
EP0084627A1 (en) 1983-08-03
US4529026A (en) 1985-07-16
US4609033A (en) 1986-09-02
EP0084627B1 (en) 1986-05-07
EP0170765B1 (en) 1988-08-31
PL239713A1 (en) 1983-08-01

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