EP0711616A2 - Device for casting metals - Google Patents

Device for casting metals Download PDF

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Publication number
EP0711616A2
EP0711616A2 EP95116400A EP95116400A EP0711616A2 EP 0711616 A2 EP0711616 A2 EP 0711616A2 EP 95116400 A EP95116400 A EP 95116400A EP 95116400 A EP95116400 A EP 95116400A EP 0711616 A2 EP0711616 A2 EP 0711616A2
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EP
European Patent Office
Prior art keywords
melt
casting
riser pipe
level
line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95116400A
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German (de)
French (fr)
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EP0711616B1 (en
EP0711616A3 (en
Inventor
Alfred Dr. Walter
Hans-Jürgen Lau
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bachmann Giesserei und Formenbau GmbH and Co KG
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Bachmann Giesserei und Formenbau GmbH and Co KG
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Publication of EP0711616A2 publication Critical patent/EP0711616A2/en
Publication of EP0711616A3 publication Critical patent/EP0711616A3/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/20Accessories: Details
    • B22D17/30Accessories for supplying molten metal, e.g. in rations
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/02Hot chamber machines, i.e. with heated press chamber in which metal is melted
    • B22D17/04Plunger machines

Definitions

  • the invention relates to a device for casting metals, in particular alloys with a low melting point, with a melt container, which is connected to a casting mold via a pouring line, with a riser branching from the pouring line, which has an overflow opening over which the level of the metal level is adjustable in the pouring line and can be opened and closed via an overflow valve, and with a check valve in the pouring line, which prevents the melt from flowing back into the melt container.
  • Devices of this type are used, for example, in the production of lost cores for plastic injection-molded parts, as are used, inter alia, in the automotive industry. Since falling casting must be avoided in this case, the melt from the melt container is poured into the casting mold from below via the casting line and then, for example, the casting pressure is maintained until the metal in the casting mold has completely solidified. In order to remove the solidified casting from the mold and to change the tool, the connection between the casting line and the casting mold must be interrupted, and no liquid metal may flow out. At the same time, however, the pouring line should not be completely emptied in order to save time for the next pouring process and to avoid deposits on the walls of the pouring line.
  • the metal mirror in the Line set so that it is slightly below the point of separation between the mold and line.
  • the metal level in the system is specified via a riser pipe, the height of which corresponds to the desired metal level.
  • an overflow opening is provided in the riser pipe, which can be opened via an overflow valve.
  • the overflow opening is opened so that excess metal can flow off.
  • the pouring pipe and the riser pipe form communicating tubes so that the metal level in the pouring pipe cannot drop below the height specified by the overflow opening of the riser pipe.
  • a check valve prevents the melt from flowing back from the pouring line into the storage container.
  • the riser pipe is arranged outside the melting vessel, so that it has to be heated in order to prevent the melt from solidifying in the riser pipe.
  • the melt flowing out via the overflow opening is freely returned to the melt container. As the liquid metal comes into contact with air, oxidation can occur which affects the quality of the melt.
  • the object of the invention is therefore to enable the setting of the metal level in the system without the need for additional heating devices for the riser pipe.
  • the riser pipe is arranged within the melt container and is surrounded by the melt at least over part of its height. In this way, the melt contained in the riser pipe is automatically kept at the melting temperature, so that no additional heating devices are required. In addition, the ways for that The metal flows back from the riser pipe into the melt container shortened.
  • an inert medium is provided above the melt and the overflow opening of the riser pipe is below the level of the inert medium. This ensures that the liquid metal emerging from the overflow opening does not come into contact with air, so that oxidation is prevented and an optimal quality of the melt is ensured.
  • the inert medium provided above the melt also prevents oxidation on the metal surface of the melt container.
  • the inert medium is an inert liquid, in particular glycol, since this considerably simplifies handling.
  • an inert gas preferably nitrogen, can also be used.
  • level meters are provided in the melt container, via which the level of the melt and / or of the inert Medium is noticeable. This means that new melt can be supplied in good time.
  • the height of the overflow opening is preferably at or somewhat below the height of the separation point between the casting line and the casting mold.
  • the length of the riser pipe can be changed in order to be adaptable to different tool dimensions.
  • the overflow valve can be opened and closed in coordination with the casting process. Since pressure is released in the pouring line when the overflow valve is opened, the pouring process can be ended in a targeted manner via the overflow valve.
  • the overflow valve can preferably be actuated via a control device located outside the melting vessel.
  • the melt is usually conveyed to the casting mold by means of a pump.
  • the valves required for the pumping process are arranged in a valve block from which the pouring line branches off.
  • the riser branches off from the pouring line within the valve block, so that the riser pipe, the overflow valve and the valve block form a structural unit which can be inserted pre-assembled into the melt container.
  • the single figure shows a schematic representation of a casting device according to the invention.
  • Liquid metal 2 in particular an alloy with a low melting point, is contained in a melt container 1, for example an insulated double-walled steel tank.
  • the metal 2 is fed via a, for example, flexible, heated casting line 3 to a casting mold 4 into which the metal is poured from bottom to top.
  • the liquid metal 2 is pressed into the mold 4 under pressure, the air contained in the mold 4 escaping through a gap 7 between the mold halves 5, 6 or a relief valve (not shown).
  • the metal 2 is conveyed from the melt container 1 via a metering pump 8 into the casting line 3 and the casting mold 4.
  • the metering pump 8 is designed as a piston pump, the piston 9 being hydraulically drivable, for example, via a drive device 10. Liquid metal is usually sucked into the cylinder chamber 12 by lifting the piston 9 via a suction channel 11 and, after closing a valve 13, pressed into the pouring line 3 by lowering the piston 9.
  • the pouring line 3 is shut off by a check valve 14, so that no melt can flow back into the melt container when the pressure is released.
  • the metering pump 8 and the associated valves 13, 14 are provided in a valve block 15 which can be inserted in the melt container 1 as a pre-assembled unit.
  • a riser pipe 16 branches off from the casting line 3 within the valve block 15 and is surrounded by the melt 2 within the melt container 1 at least over part of its height. This ensures that the metal contained in the riser pipe does not cool or solidify.
  • the riser pipe 16 has an overflow opening 17 which can be opened or closed by an overflow or bypass valve 18.
  • the overflow valve 18 is located outside of the melt container 1 lying control device 19 actuated.
  • a gas preferably nitrogen, can also be used.
  • the level of the inert liquid 20 exceeds the overflow opening 17 of the riser pipe 16.
  • level gauges 21, 22 are provided in order to be able to control the level of the melt level and the level of the inert liquid 20, level gauges 21, 22 are provided.
  • the temperature of the melt is also monitored by a temperature sensor 23.
  • the liquid metal 2 is filled by means of the metering pump 8 via the pouring line 3 into the mold 4 from below, the casting pressure being maintained, for example, until the metal solidifies in the mold 4 is.
  • the connection between the casting line 3 and the mold 4 must be interrupted.
  • the metal level 25 in the system must be set somewhat below the separation point 26 between the casting line 3 and the casting mold 4.
  • the overflow valve 18 of the riser pipe 16 is opened, which brings about a pressure relief in the pouring line 3, with excess metal via the overflow opening 17 can flow back into the melt container 1.
  • the riser pipe 16 and the pouring line 3 form communicating tubes, so that the metal level 25 in the pouring line 3 cannot drop below the height of the overflow opening 17.
  • the height of the metal level 25 in the pouring line 3 can thus be set precisely by a corresponding adjustment of the length of the riser pipe 16.
  • the check valve 14 in the valve block 15 prevents the metal from flowing back into the melt container 1.
  • the inert liquid 20 in particular glycol
  • the metal emerging from the overflow opening 17 of the riser pipe 16 does not come into contact with air, but flows through the inert liquid 20 back into the melt bath. This prevents oxidation of the metal flowing back and the melt 2 retains the desired composition.
  • the level of the inert liquid 20 is monitored by means of the fill level meters 21, 22, so that additional melt can be supplied in good time.
  • the metal level 25 in the pouring line 3 is thus kept at the desired height in a simple manner, with no additional heating for the riser pipe 16 being required. At the same time, oxidation of the metal flowing back via the overflow opening 17 by the inert liquid 20 is reliably prevented.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)

Abstract

Metals, partic. low m.pt. alloys, car cast using an arrangement of a melting vessel (1) connected by a casting line (3) to a mould (4). A rising pipe (16) branches from the casting line within the melting vessel and is surrounded of at least part of its height by melt. The pipe has an overflow aperture (17) for adjusting the molten metal level which can be opened and closed via a valve (18). A check valve (14) in the casting line prevents metal flowing back into the vessel. Pref. an inert medium (20) is provided over the melt (2), the overflow aperture being below the level of the inert medium. Pref. inert medium is a liquid, partic. glycol, partic. a gas, partic. N.

Description

Die Erfindung berifft eine Vorrichtung zum Gießen von Metallen, insbesondere von Legierungen mit niedrigem Schmelzpunkt, mit einem Schmelzebehälter, der über eine Gießleitung mit einer Gießform verbunden ist, mit einem von der Gießleitung abzweigenden Steigrohr, das eine Überströmöffnung aufweist, über die das Niveau des Metallspiegels in der Gießleitung einstellbar ist und die über ein Überströmventil geöffnet und verschlossen werden kann, und mit einem Rückschlagventil in der Gießleitung, das ein Zurückfließen der Schmelze in den Schmelzebehälter verhindert.The invention relates to a device for casting metals, in particular alloys with a low melting point, with a melt container, which is connected to a casting mold via a pouring line, with a riser branching from the pouring line, which has an overflow opening over which the level of the metal level is adjustable in the pouring line and can be opened and closed via an overflow valve, and with a check valve in the pouring line, which prevents the melt from flowing back into the melt container.

Derartige Vorrichtungen werden bspw. bei der Herstellung verlorener Kerne für Kunststoff-Spritzgußteile angewandt, wie sie u.a. in der Automobilindustrie eingesetzt werden. Da hierbei fallender Guß vermieden werden muß, wird die Schmelze aus dem Schmelzebehälter über die Gießleitung von unten in die Gießform eingefüllt und anschließend bspw. der Gießdruck solange aufrechterhalten, bis das Metall in der Gießform vollständig erstarrt ist. Um das erstarrte Gußteil aus der Form zu entnehmen und um das Werkzeug zu wechseln, muß die Verbindung zwischen der Gießleitung und der Gießform unterbrochen werden, wobei kein flüssiges Metall ausfließen darf. Gleichzeitig soll aber die Gießleitung nicht vollständig entleert werden, um für den nächsten Gießvorgang Zeit zu sparen und Ablagerungen an den Wänden der Gießleitung zu vermeiden. Zu diesem Zweck wird der Metallspiegel in der Leitung so eingestellt, daß er etwas unterhalb der Trennstelle zwischen Gießform und Leitung stabil steht. Bei einer bekannten Vorrichtung wird das Metallniveau im System über ein Steigrohr vorgegeben, dessen Höhe dem gewünschten Metallniveau entspricht. An der dem gewünschten Metallniveau entsprechenden Höhe ist in dem Steigrohr eine Überströmöffnung vorgesehen, die über ein Überströmventil geöffnet werden kann. Nach Beendigung des Gießvorgangs wird die Überströmöffnung geöffnet, so daß überschüssiges Metall abfließen kann. Die Gießleitung und das Steigrohr bilden kommunizierende Röhren, so daß das Metallniveau in der Gießleitung nicht unter die durch die Überströmöffnung des Steigrohrs vorgegebene Höhe absinken kann. Hierbei wird ein Zurückfließen der Schmelze aus der Gießleitung in den Vorratsbehälter durch ein Rückschlagventil verhindert. Bei der bekannten Vorrichtung ist das Steigrohr außerhalb des Schmelzbehälters angeordnet, so daß es beheizt werden muß, um ein Erstarren der Schmelze in dem Steigrohr zu verhindern. Die über die Überströmöffnung abfließende Schmelze wird frei in den Schmelzebehälter zurückgeleitet. Da das flüssige Metall hierbei mit Luft in Berührung kommt, kann es zu einer Oxidation kommen, die die Qualität der Schmelze beeinträchtigt.Devices of this type are used, for example, in the production of lost cores for plastic injection-molded parts, as are used, inter alia, in the automotive industry. Since falling casting must be avoided in this case, the melt from the melt container is poured into the casting mold from below via the casting line and then, for example, the casting pressure is maintained until the metal in the casting mold has completely solidified. In order to remove the solidified casting from the mold and to change the tool, the connection between the casting line and the casting mold must be interrupted, and no liquid metal may flow out. At the same time, however, the pouring line should not be completely emptied in order to save time for the next pouring process and to avoid deposits on the walls of the pouring line. For this purpose, the metal mirror in the Line set so that it is slightly below the point of separation between the mold and line. In a known device, the metal level in the system is specified via a riser pipe, the height of which corresponds to the desired metal level. At the height corresponding to the desired metal level, an overflow opening is provided in the riser pipe, which can be opened via an overflow valve. After the casting process has ended, the overflow opening is opened so that excess metal can flow off. The pouring pipe and the riser pipe form communicating tubes so that the metal level in the pouring pipe cannot drop below the height specified by the overflow opening of the riser pipe. A check valve prevents the melt from flowing back from the pouring line into the storage container. In the known device, the riser pipe is arranged outside the melting vessel, so that it has to be heated in order to prevent the melt from solidifying in the riser pipe. The melt flowing out via the overflow opening is freely returned to the melt container. As the liquid metal comes into contact with air, oxidation can occur which affects the quality of the melt.

Aufgabe der Erfindung ist es daher, die Einstellung des Metallniveaus in dem System zu ermöglichen, ohne daß zusätzliche Heizvorrichtungen für das Steigrohr benötigt werden.The object of the invention is therefore to enable the setting of the metal level in the system without the need for additional heating devices for the riser pipe.

Diese Aufgabe wird mit der Erfindung im wesentlichen dadurch gelöst, daß das Steigrohr innerhalb des Schmelzebehälters angeordnet ist und wenigstens über einen Teil seiner Höhe von der Schmelze umgeben ist. Auf diese Weise wird die in dem Steigrohr enthaltene Schmelze automatisch auf Schmelztemperatur gehalten, so daß keine zusätzlichen Heizvorrichtungen benötigt werden. Außerdem werden die Wege für das Zurück-fließen des Metalls aus dem Steigrohr in den Schmelze behälter verkürzt.This object is essentially achieved with the invention in that the riser pipe is arranged within the melt container and is surrounded by the melt at least over part of its height. In this way, the melt contained in the riser pipe is automatically kept at the melting temperature, so that no additional heating devices are required. In addition, the ways for that The metal flows back from the riser pipe into the melt container shortened.

Bei einer bevorzugten Ausgestaltung der Erfindung ist über der Schmelze ein inertes Medium vorgesehen, und die Überströmöffnung des Steigrohrs liegt unterhalb des Spiegels des Inertmediums. Hierdurch wird sichergestellt, daß das aus der Überströmöffnung austretende flüssige Metall nicht mit Luft in Berührung kommt, so daß eine Oxiation verhindert und eine optimale Qualität der Schmelze gewährleistet wird. Durch das über der Schmelze vorgesehene inerte Medium wird außerdem eine Oxidation am Metallspiegel des Schmelzebehälters verhindert.In a preferred embodiment of the invention, an inert medium is provided above the melt and the overflow opening of the riser pipe is below the level of the inert medium. This ensures that the liquid metal emerging from the overflow opening does not come into contact with air, so that oxidation is prevented and an optimal quality of the melt is ensured. The inert medium provided above the melt also prevents oxidation on the metal surface of the melt container.

In Weiterbildung dieses Erfindungsgedankens ist das inerte Medium eine inerte Flüssigkeit, insbesondere Glykol, da hierdurch die Handhabung wesentlich vereinfacht wird. Als Alternative kann auch ein inertes Gas, vorzugsweise Stickstoff, verwendet werden.In a further development of this inventive concept, the inert medium is an inert liquid, in particular glycol, since this considerably simplifies handling. Alternatively, an inert gas, preferably nitrogen, can also be used.

Um zu verhindern, daß im Laufe der Zeit das Niveau des inerten Mediums in dem Schmelzebehalter so weit absinkt, daß die Überströmöffnung des Steigrohrs oberhalb der Inertflüssigkeit liegt, sind erfindungsgemäß in dem Schmelzebehälter Füllstandsmesser vorgesehen, über die das Niveau der Schmelze und/oder des inerten Mediums feststellbar ist. Somit kann rechtzeitig neue Schmelze zugeführt werden.In order to prevent the level of the inert medium in the melt container from dropping so far over time that the overflow opening of the riser pipe lies above the inert liquid, according to the invention level meters are provided in the melt container, via which the level of the melt and / or of the inert Medium is noticeable. This means that new melt can be supplied in good time.

Zur Vermeidung des Austretens von flüssigem Metall beim Trennen der Verbindung zwischen Gießform und Gießleitung, liegt die Höhe der Überströmöffnung vorzugsweise auf oder etwas unterhalb der Höhe der Trennstelle von Gießleitung und Gießform.To prevent liquid metal from escaping when the connection between the casting mold and the casting line is separated, the height of the overflow opening is preferably at or somewhat below the height of the separation point between the casting line and the casting mold.

In Weiterbildung dieses Erfindungsgedankens ist die Länge des Steigrohrs veränderbar, um an verschiedene Werkzeugdimensionen anpaßbar zu sein.In a further development of this inventive concept, the length of the riser pipe can be changed in order to be adaptable to different tool dimensions.

Bei einer bevorzugten Ausgestaltung der Erfindung ist das Überströmventil in Abstimmung mit dem Gießvorgang öffenbar und verschließbar. Da beim Öffnen des Überströmventils eine Druckentlastung in der Gießleitung erfolgt, kann über das Überströmventil der Gießvorgang gezielt beendet werden.In a preferred embodiment of the invention, the overflow valve can be opened and closed in coordination with the casting process. Since pressure is released in the pouring line when the overflow valve is opened, the pouring process can be ended in a targeted manner via the overflow valve.

Vorzugsweise ist hierbei das Überströmventil über eine außerhalb des Schmelzbehälters liegende Kontrolleinrichtung betätigbar.In this case, the overflow valve can preferably be actuated via a control device located outside the melting vessel.

Üblicherweise wird bei gattungsgemäßen Vorrichtungen die Schmelze über eine Pumpe zu der Gießform gefördert. Die für den Pumpvorgang nötigen Ventile sind in einem Ventilblock angeordnet, von dem die Gießleitung abzweigt. In Weiterbildung des Erfindungsgedankens zweigt das Steigrohr innerhalb des Ventilblocks von der Gießleitung ab, so daß das Steigrohr, das Überströmventil und der Ventilblock eine Baueinheit bilden, die vormontiert in den Schmelzebehälter eingesetzt werden kann.In the case of generic devices, the melt is usually conveyed to the casting mold by means of a pump. The valves required for the pumping process are arranged in a valve block from which the pouring line branches off. In a further development of the inventive concept, the riser branches off from the pouring line within the valve block, so that the riser pipe, the overflow valve and the valve block form a structural unit which can be inserted pre-assembled into the melt container.

Weiterbildungen, Vorteile und Anwendungsmöglichkeiten der Erfindung ergeben sich aus der nachfolgenden Beschreibung eines Ausführungsbeispiels und der Zeichnung. Dabei bilden alle beschriebenen und/oder bildlich dargestellten Merkmale für sich oder in beliebiger Kombination den Gegenstand der Erfindung, unabhängig von ihrer Zusammenfassung in den Ansprüchen oder deren Rückbeziehung.Further developments, advantages and possible applications of the invention result from the following description of an exemplary embodiment and the drawing. All of the described and / or illustrated features, alone or in any combination, form the subject matter of the invention, regardless of their summary in the claims or their relationship.

Die einzige Figur zeigt eine schematische Darstellung einer erfindungsgemäßen Gießvorrichtung.The single figure shows a schematic representation of a casting device according to the invention.

In einem Schmelzebehälter 1, bspw. einem isolierten doppelwandigen Stahltank, ist flüssiges Metall 2, insbesondere eine Legierung mit niedrigem Schmelzpunkt, enthalten. Das Metall 2 wird über eine bspw. flexible, beheizte Gießleitung 3 einer Gießform 4 zugeführt, in die das Metall von unten nach oben eingefüllt wird. Das flüssige Metall 2 wird dabei unter Druck in die Gießform 4 eingepreßt, wobei die in der Gießform 4 enthaltene Luft durch einen zwischen den Formhälften 5, 6 bestehenden Spalt 7 oder ein nicht dargestelltes Entlastungventil entweicht.Liquid metal 2, in particular an alloy with a low melting point, is contained in a melt container 1, for example an insulated double-walled steel tank. The metal 2 is fed via a, for example, flexible, heated casting line 3 to a casting mold 4 into which the metal is poured from bottom to top. The liquid metal 2 is pressed into the mold 4 under pressure, the air contained in the mold 4 escaping through a gap 7 between the mold halves 5, 6 or a relief valve (not shown).

Das Metall 2 wird aus dem Schmelzebehälter 1 über eine Dosierpumpe 8 in die Gießleitung 3 und die Gießform 4 gefördert. Die Dosierpumpe 8 ist als Kolbenpumpe ausgebildet, wobei der Kolben 9 bspw. hydraulisch über eine Antriebseinrichtung 10 antreibbar ist. Üblicherweise wird dabei flüssiges Metall durch Anheben des Kolbens 9 über einen Ansaugkanal 11 in die Zylinderkammer 12 eingesaugt und nach Schließen eines Ventils 13 durch Absenken des Kolbens 9 in die Gießleitung 3 eingepreßt. Die Gießleitung 3 ist dabei durch ein Rückschlagventil 14 abgesperrt, so daß bei Druckentlastung keine Schmelze in den Schmelzebehälter zurückfließen kann. Die Dosierpumpe 8 und die zugehörigen Ventile 13, 14 sind in einem Ventilblock 15 vorgesehen, der als Baueinheit vormontiert in den Schmelzebehälter 1 einsetzbar ist.The metal 2 is conveyed from the melt container 1 via a metering pump 8 into the casting line 3 and the casting mold 4. The metering pump 8 is designed as a piston pump, the piston 9 being hydraulically drivable, for example, via a drive device 10. Liquid metal is usually sucked into the cylinder chamber 12 by lifting the piston 9 via a suction channel 11 and, after closing a valve 13, pressed into the pouring line 3 by lowering the piston 9. The pouring line 3 is shut off by a check valve 14, so that no melt can flow back into the melt container when the pressure is released. The metering pump 8 and the associated valves 13, 14 are provided in a valve block 15 which can be inserted in the melt container 1 as a pre-assembled unit.

Von der Gießleitung 3 zweigt innerhalb des Ventilblocks 15 ein Steigrohr 16 ab, das innerhalb des Schmelzebehälters 1 wenigstens über einen Teil seiner Höhe von der Schmelze 2 umgeben ist. Dadurch wird sichergestellt, daß das in dem Steigrohr enthaltene Metall nicht abkühlt bzw. erstarrt. Das Steigrohr 16 weist eine Überströmöffnung 17 auf, die durch ein Überström- oder Bypassventil 18 geöffnet bzw. verschlossen werden kann. Das Überströmventil 18 wird über eine aus-serhalb des Schmelzebehälters 1 liegende Kontrolleinrichtung 19 betätigt.A riser pipe 16 branches off from the casting line 3 within the valve block 15 and is surrounded by the melt 2 within the melt container 1 at least over part of its height. This ensures that the metal contained in the riser pipe does not cool or solidify. The riser pipe 16 has an overflow opening 17 which can be opened or closed by an overflow or bypass valve 18. The overflow valve 18 is located outside of the melt container 1 lying control device 19 actuated.

Auf dem flüssigen Metall 2 ist eine inerte Flüssigkeit 20, inbesondere Glykol, vorgesehen, die eine Oxidation am Schmelzespiegel verhindert. Statt der Flüssigkeit kann auch ein Gas, vorzugsweise Stickstoff, verwendet werden. Das Niveau der inerten Flüssigkeit 20 übersteigt die Überströmöffnung 17 des Steigrohrs 16. Um das Niveau des Schmelzspiegels sowie des Spiegels der inerten Flüssigkeit 20 kontrollieren zu können, sind Füllstandsmesser 21, 22 vorgesehen. Die Temperatur der Schmelze wird außerdem über einen Temperaturfühler 23 überwacht.An inert liquid 20, in particular glycol, is provided on the liquid metal 2, which prevents oxidation at the melt level. Instead of the liquid, a gas, preferably nitrogen, can also be used. The level of the inert liquid 20 exceeds the overflow opening 17 of the riser pipe 16. In order to be able to control the level of the melt level and the level of the inert liquid 20, level gauges 21, 22 are provided. The temperature of the melt is also monitored by a temperature sensor 23.

Nachfolgend wird die Funktion der erfindungsgemäßen Vorrichtung beschrieben.The function of the device according to the invention is described below.

Zum Gießen bspw. eines verlorenen Kernes 24 für Kunststoff-Spritzgußteile, wie sie u.a. zur Serienfertigung von Kunststoffteilen in der Automobilindustrie verwendet werden, wird das flüssige Metall 2 mittels der Dosierpumpe 8 über die Gießleitung 3 von unten nach oben in die Gießform 4 eingefüllt, wobei der Gießdruck bspw. solange aufrechterhalten wird, bis das Metall in der Gießform 4 erstarrt ist. Zum Entnehmen des Kernes 24 aus der Gießform 4 oder zum Wechseln des Werkzeugs muß die Verbindung zwischen der Gießleitung 3 und der Gießform 4 unterbrochen werden. Um dabei ein Herausfließen des flüssigen Metalls 2 aus der Gießleitung 3 zu verhindern, muß das Metallniveau 25 im System etwas unterhalb der Trennstelle 26 zwischen Gießleitung 3 und Gießform 4 eingestellt werden.For casting, for example, a lost core 24 for plastic injection molded parts, such as those are used for the series production of plastic parts in the automotive industry, the liquid metal 2 is filled by means of the metering pump 8 via the pouring line 3 into the mold 4 from below, the casting pressure being maintained, for example, until the metal solidifies in the mold 4 is. To remove the core 24 from the mold 4 or to change the tool, the connection between the casting line 3 and the mold 4 must be interrupted. In order to prevent the liquid metal 2 from flowing out of the casting line 3, the metal level 25 in the system must be set somewhat below the separation point 26 between the casting line 3 and the casting mold 4.

Zu diesem Zweck wird das Überströmventil 18 des Steigrohrs 16 geöffnet, was eine Druckentlastung in der Gießleitung 3 bewirkt, wobei überschüssiges Metall über die Überströmöffnung 17 in den Schmelzebehälter 1 zurückfließen kann. Das Steigrohr 16 und die Gießleitung 3 bilden kommunizierende Röhren, so daß das Metallnivau 25 in der Gießleitung 3 nicht unter die Höhe der Überströmöffnung 17 absinken kann. Durch eine entsprechende Einstellung der Länge des Steigrohrs 16 kann somit die Höhe des Metallnivaus 25 in der Gießleitung 3 genau eingestellt werden. Ein Zurückfließen des Metalls in den Schmelzebehälter 1 wird durch das Rückschlagventil 14 in dem Ventilblock 15 verhindert.For this purpose, the overflow valve 18 of the riser pipe 16 is opened, which brings about a pressure relief in the pouring line 3, with excess metal via the overflow opening 17 can flow back into the melt container 1. The riser pipe 16 and the pouring line 3 form communicating tubes, so that the metal level 25 in the pouring line 3 cannot drop below the height of the overflow opening 17. The height of the metal level 25 in the pouring line 3 can thus be set precisely by a corresponding adjustment of the length of the riser pipe 16. The check valve 14 in the valve block 15 prevents the metal from flowing back into the melt container 1.

Da über dem flüssigen Metall 2 in dem Schmelzebehälter 1 die inerte Flüssigkeit 20, insbesondere Glykol, vorgesehen ist, die auch die Überströmöffnung 17 des Steigrohrs 16 übersteigt, kommt das aus der Überströmöffnung 17 des Steigrohrs 16 austretende Metall nicht mit Luft in Berührung, sondern fließt durch die inerte Flüssigkeit 20 in das Schmelzebad zurück. Dadurch wird eine Oxidation des zurückfließenden Metalls verhindert und die Schmelze 2 behält die gewünschte Zusammensetzung.Since the inert liquid 20, in particular glycol, is provided above the liquid metal 2 in the melt container 1 and also exceeds the overflow opening 17 of the riser pipe 16, the metal emerging from the overflow opening 17 of the riser pipe 16 does not come into contact with air, but flows through the inert liquid 20 back into the melt bath. This prevents oxidation of the metal flowing back and the melt 2 retains the desired composition.

Um zu verhindern, daß das Niveau der inerten Flüssigkeit 20 bis unterhalb der Überströmöffnung 17 sinkt, wird das Niveau der Schmelze 2 und der inerten Flüssigkeit 20 über die Füllstandsmesser 21, 22 überwacht, so daß rechtzeitig zusätzliche Schmelze zugeführt werden kann.In order to prevent the level of the inert liquid 20 from falling below the overflow opening 17, the level of the melt 2 and the inert liquid 20 is monitored by means of the fill level meters 21, 22, so that additional melt can be supplied in good time.

Durch die erfindungsgemäße Vorrichtung wird somit das Metallniveau 25 in der Gießleitung 3 auf einfache Weise auf der gewünschten Höhe gehalten, wobei eine zusätzliche Heizung für das Steigrohr 16 nicht benötigt wird. Gleichzeitig wird eine Oxidation des über die Überströmöffnung 17 zurückfließenden Metalls durch die inerte Flüssigkeit 20 zuverlässig verhindert.With the device according to the invention, the metal level 25 in the pouring line 3 is thus kept at the desired height in a simple manner, with no additional heating for the riser pipe 16 being required. At the same time, oxidation of the metal flowing back via the overflow opening 17 by the inert liquid 20 is reliably prevented.

Bezugszeichenliste:Reference symbol list:

11
SchmelzebehälterMelt container
22nd
flüssiges Metallliquid metal
33rd
GießleitungPouring pipe
44th
GießformMold
55
FormhälfteMold half
66
FormhälfteMold half
77
Spaltecolumn
88th
DosierpumpeDosing pump
99
Kolbenpiston
1010th
AntriebseinrichtungDrive device
1111
AnsaugkanalIntake duct
1212th
ZylinderkammerCylinder chamber
1313
VentilValve
1414
Rückschlagventilcheck valve
1515
VentilblockValve block
1616
SteigrohrRiser pipe
1717th
ÜberströmöffnungOverflow opening
1818th
ÜberströmventilOverflow valve
1919th
KontrolleinrichtungControl device
2020th
inerte Flüssigkeitinert liquid
2121
FüllstandsmesserLevel meter
2222
FüllstandsmesserLevel meter
2323
TemperaturfühlerTemperature sensor
2424th
Kerncore
2525th
MetallniveauMetal level
2626
TrennstelleSeparation point

Claims (10)

Vorrichtung zum Gießen von Metallen, inbesondere von Legierungen mit niedrigem Schmelzpunkt, mit einem Schmelzebehälter (1), der über eine Gießleitung (3) mit einer Gießform (4) verbunden ist, mit einem von der Gießleitung (3) abzweigenden Steigrohr (16), das eine Überströmöffnung (17) aufweist, über die das Niveau (25) des Metallspiegels in der Gießleitung (3) einstellbar ist und die über ein Überströmventil (18) öffenbar und verschließbar ist, und mit einem Rückschlagventil (14) in der Gießleitung (3), das ein Zurückfließen der Schmelze in den Schmelzebehälter (1) verhindert, dadurch gekennzeichnet, daß das Steigrohr (16) innerhalb des Schmelzebehälters (1) angeordnet ist und wenigstens über einen Teil seiner Höhe von der Schmelze umgeben ist.Device for casting metals, in particular alloys with a low melting point, with a melt container (1) which is connected to a casting mold (4) via a casting line (3), with a riser pipe (16) branching off from the casting line (3), which has an overflow opening (17) through which the level (25) of the metal mirror in the pouring line (3) can be adjusted and which can be opened and closed via an overflow valve (18), and with a check valve (14) in the pouring line (3 ), which prevents the melt from flowing back into the melt container (1), characterized in that the riser pipe (16) is arranged inside the melt container (1) and is surrounded by the melt at least over part of its height. Vorrichtung nach Anspruch 1, dadurch gekennzeichnt, daß über der Schmelze (2) ein inertes Medium (20) vorgesehen ist, und daß die Überströmöffnung (17) des Steigrohrs (16) un terhalb des Spiegels des inerten Mediums (20) liegt.Apparatus according to claim 1, characterized in that an inert medium (20) is provided above the melt (2) and that the overflow opening (17) of the riser pipe (16) is below the level of the inert medium (20). Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß das inerte Medium (20) eine inerte Flüssigkeit, insbesondere Glykol ist.Device according to claim 2, characterized in that the inert medium (20) is an inert liquid, in particular glycol. Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß das inerte Medium (20) ein Gas, insbesondere Stickstoff, ist.Device according to claim 2, characterized in that the inert medium (20) is a gas, in particular nitrogen. Vorrichtung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß in dem Schmelzebehälter (1) Füllstandsmesser (21, 22) vorgesehen sind, über die das Niveau der Schmelze und/oder des inerten Mediums (20) feststellbar ist.Device according to one of claims 1 to 4, characterized in that level meters (21, 22) are provided in the melt container (1), by means of which the level of the melt and / or the inert medium (20) can be determined. Vorrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Höhe der Überströmöffnung (17) auf oder etwas unterhalb der Höhe der Trennstelle (26) von Gießleitung (3) und Gießform (4) liegt.Device according to one of claims 1 to 5, characterized in that the height of the overflow opening (17) is at or slightly below the height of the separation point (26) of the casting line (3) and casting mold (4). Vorrichtung nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß die Länge des Steigrohrs (16) veränderbar ist.Device according to one of claims 1 to 6, characterized in that the length of the riser pipe (16) is variable. Vorrichtung nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß das Überströmventil (18) in Abstimmung mit dem Gießvorgang öffenbar und verschließbar ist.Device according to one of claims 1 to 7, characterized in that the overflow valve (18) can be opened and closed in coordination with the casting process. Vorrichtung nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, daß das Überströmventil (18) über eine ausserhalb des Schmelzebehälters (1) liegende Kontrolleinrichtung (19) betätigbar ist.Device according to one of claims 1 to 8, characterized in that the overflow valve (18) can be actuated via a control device (19) located outside the melt container (1). Vorrichtung nach einem der Ansprüche 1 bis 9, wobei die Schmelze über eine Pumpe (8) zu der Gießform (4) gefördert wird und die für den Pumpvorgang nötigen Ventile (13, 14) in einem Ventilblock (15) angeordnet sind, von dem die Gießleitung (3) abzweigt, dadurch gekennzeichnet, daß das Steigrohr (16) innerhalb des Ventilblocks (15) von der Gießleitung (3) abzweigt.Device according to one of claims 1 to 9, wherein the melt is conveyed to the casting mold (4) via a pump (8) and the valves (13, 14) required for the pumping process are arranged in a valve block (15), of which the Casting line (3) branches, characterized in that the riser pipe (16) branches off from the pouring line (3) within the valve block (15).
EP95116400A 1994-11-15 1995-10-18 Device for casting metals Expired - Lifetime EP0711616B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4440768A DE4440768C1 (en) 1994-11-15 1994-11-15 Device for casting metals
DE4440768 1994-11-15

Publications (3)

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EP0711616A2 true EP0711616A2 (en) 1996-05-15
EP0711616A3 EP0711616A3 (en) 1997-05-07
EP0711616B1 EP0711616B1 (en) 1999-05-26

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ID=6533377

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EP95116400A Expired - Lifetime EP0711616B1 (en) 1994-11-15 1995-10-18 Device for casting metals

Country Status (5)

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US (1) US5657812A (en)
EP (1) EP0711616B1 (en)
JP (1) JPH08224651A (en)
CA (1) CA2162800A1 (en)
DE (2) DE4440768C1 (en)

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Also Published As

Publication number Publication date
DE4440768C1 (en) 1996-07-25
EP0711616B1 (en) 1999-05-26
EP0711616A3 (en) 1997-05-07
CA2162800A1 (en) 1996-05-16
US5657812A (en) 1997-08-19
DE59506022D1 (en) 1999-07-01
JPH08224651A (en) 1996-09-03

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