EP0078897B1 - Low-pressure connection for moulds consolidated under vacuum - Google Patents

Low-pressure connection for moulds consolidated under vacuum Download PDF

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Publication number
EP0078897B1
EP0078897B1 EP82108197A EP82108197A EP0078897B1 EP 0078897 B1 EP0078897 B1 EP 0078897B1 EP 82108197 A EP82108197 A EP 82108197A EP 82108197 A EP82108197 A EP 82108197A EP 0078897 B1 EP0078897 B1 EP 0078897B1
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EP
European Patent Office
Prior art keywords
valve body
piston
rod
valve
pressure medium
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.)
Expired
Application number
EP82108197A
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German (de)
French (fr)
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EP0078897A1 (en
Inventor
Herbert Grolla
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.)
Heinrich Wagner Sinto Maschinenfabrik GmbH
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Heinrich Wagner Sinto Maschinenfabrik GmbH
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Priority to AT82108197T priority Critical patent/ATE19211T1/en
Publication of EP0078897A1 publication Critical patent/EP0078897A1/en
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Publication of EP0078897B1 publication Critical patent/EP0078897B1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/03—Sand moulds or like moulds for shaped castings formed by vacuum-sealed moulding

Definitions

  • the invention relates to a vacuum coupling for the connection of mold boxes for vacuum-hardened casting molds to a vacuum network, with a valve body movably guided on a rod and acted upon by a prestressing force in the direction of the mold box, which valve body has a connection opening surrounded by a seal and between the latter and a negative pressure connection contains a valve, which is formed by a valve seat in the valve body and a valve plate carried by the rod, is kept closed by the pretensioning force and, in relation to the pretensioning force, results in a relative movement of the valve body with respect to the pretensioning force, caused by the pressing of the coupling the rod opens.
  • the dimensional stability is determined by the inside of the casting mold, i.e. H. obtained in the molding compound, generated negative pressure. This negative pressure must be used to manufacture the.
  • the casting mold, during transport, during pouring and also when the casting cools down, must always be maintained, since otherwise the molding compound loses its solidified state. Since the individual processing stations can be very far apart, the mold must be connected to the vacuum connections located at the individual workplaces, which can be achieved either by simply attaching hoses by hand or by mechanically operated couplings in connection with valve controls.
  • a vacuum coupling for vacuum molding boxes known from DE-A-2710481 is also arranged in a stationary manner, and the molding box must be moved so close to the vacuum coupling until the gap remaining between them has become so small that the vacuum applied is sufficient to counter the force against the valve a return spring is sucked onto the wall of the molding box over a short distance. This way of working is associated with considerable functional uncertainty and with a considerable loss of vacuum.
  • the invention has for its object a vacuum clutch of the type mentioned, d. H. to create with valve automatically opening when coupling, which has a simple and space-saving design and enables the connection between the mold and vacuum network, without the mold having to perform a mounting or coupling movement to the coupling.
  • a vacuum clutch of the type mentioned according to the invention is characterized in that a piston working in a pressure medium cylinder is connected to the rod and that by applying pressure medium to at least one side of the piston, the rod takes the valve body against the molding box or away from it is movable.
  • valve body By simply applying pressure to the piston with pressure medium, the valve body can first be moved and pressed against the molding box over a considerable distance by means of the rod, and then automatically in the course of this pressing movement when the pressure-tight connection of the valve housing to the casting mold is already made, the opening of the valve and thus the release of the negative pressure to the casting mold takes place.
  • the pressure medium cylinder is preferably a double-acting pressure medium cylinder Pressure medium supply optionally designed for one or the other piston surface of the piston, in order to be able to carry out both the approaching and the moving away of the coupling relative to the casting box by applying pressure medium. Alternatively, however, it is also possible to simply bring the coupling closer to the casting box by applying pressure medium and pulling the coupling off using a return spring.
  • the valve body is provided with an annular piston part immersed in the pressure medium cylinder, and that the biasing force holding the valve closed is provided by a piston space in the cylinder space between the annular piston part of the valve body and the piston surface of the rod facing the latter supplied pressure medium is generated.
  • the vacuum clutch is actuated by the double-acting pressure cylinder, the cylinder chamber of the pressure cylinder adjacent to the valve body being constantly subjected to a certain pressure, while the other side of the pressure cylinder is only pressurized when the vacuum clutch is actuated, which pressure corresponds to the pressure in the first cylinder chamber corresponds.
  • the piston of the pressure cylinder is designed as a differential piston, so that the same pressure on both sides of the piston moves in the direction of the valve body. However, since the valve body is also immersed in one cylinder chamber and acted upon by the pressure medium in the axial direction, there is no relative displacement between the piston and the valve body until its contact surface rests on the casting mold.
  • This embodiment has the advantage that the rod can be extended by actuating the pressure cylinder even when the molding box is not yet in its place.
  • the piston assumes the uppermost or extended position without any relative movement between the valve body and the rod.
  • the valve remains closed until the mold is put in its place. Only when the valve body is loaded by the casting mold is the valve body moved towards the pressure cylinder so that the valve can open.
  • the vacuum clutch 1 shown in FIGS. 1 and 2 in section consists of a valve body 2, which is immersed in a pressure cylinder 19 and is guided tightly in its cylinder head 15.
  • the valve body 2 has a vacuum connection 3, to which the line coming from the vacuum network and not shown can be connected.
  • the valve body 2 is provided with a bore 6 in which a rod 5 slides, which is sealed by means of a seal 7 in the bore.
  • the end 13 of the valve body is designed as an annular piston and guided in the cylinder head 15 of the pressure cylinder 19 and sealed by means of a seal 16.
  • valve 10 In the upper region of the valve body 2, a valve 10 is formed which has an annular valve seat 9 which extends in a plane perpendicular to the rod 5. At the end of the rod 5, a valve plate 8 is arranged with an annular seal 11, which cooperates with the valve seat 9.
  • the valve body 2 forms at its free end an annular sealing surface 34 which is provided with an annular seal 35.
  • This ring seal is at a distance from the valve 10, namely such a distance that the displacement of the valve plate 8 takes place within the valve body 2.
  • the pressure cylinder 19 is designed as a double-acting cylinder and has two pressure medium connections 21 and 27.
  • the cylinder head 15 and the cylinder base 20 are connected to one another via a tube 36 and sealed with respect to them by means of seals 37.
  • the piston 17 arranged in the pressure cylinder 19, which is fixedly connected to the rod 5, is known to be sealed with respect to the tube 36 by means of sealing rings 18.
  • the length of the part 13 of the valve body 2, which is designed as an annular piston, is dimensioned such that, when the piston 17 is displaced to the maximum extent, it is sufficiently guided and sealed in the cylinder head 15.
  • the operation of the vacuum clutch according to the invention is as follows.
  • the cylinder chamber 14 is continuously connected via the connection 21 to a pressure medium source, so that a constant pressure is maintained in this.
  • This pressure is exerted on the one hand on the annular surface 22 of the piston 17 and on the other hand on the annular surface 23 of the annular piston 13, which is part of the valve body 2.
  • Pistons 17 and Annular pistons 13 are thus moved in opposite directions by the prevailing pressure, so that the rod 5 is thereby moved in the direction 24 and the valve 10 closes.
  • the magnitude of the closing force of the valve 10 is thus dependent on the size of the annular surface 23. Since the cylinder space 26 is depressurized, the piston 17 will shift in the direction 24, as shown in FIG. 1, until the valve body 2, which is carried by the valve plate 8, rests with its shoulder on the cylinder head 15.
  • the cylinder chamber 26 is pressurized via the connection 27 with the same pressure that also prevails in the cylinder chamber 14. Since the piston area 28 in the cylinder space 26 is larger by the area of the rod 5 than the ring area 22 in the cylinder space -14, the piston 17 moves in the direction 25. The distance of the piston 17 from the ring area 23 of the valve body 2 does not change, however the annular piston 13 is also displaced in the direction 25 by the pressure prevailing in the cylinder space 14. The relative distance from the annular piston 13 changes only when the sealing surface 34 comes to rest on the casting mold 30. This has the consequence that the valve plate 8 stands out from the valve seat 9 and the connection between the vacuum network and the valve outlet is thus obtained.
  • a vacuum clutch according to the invention can be installed in any position and also does not require that the mold must be moved against the vacuum clutch so that the vacuum valve 10 is opened.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
  • Manufacturing Of Electrical Connectors (AREA)
  • Coupling Device And Connection With Printed Circuit (AREA)
  • Fluid-Driven Valves (AREA)

Abstract

1. A low pressure coupling for the connection to an low pressure system of mould boxes for moulds compacted under vacuum with a valve body (2) which is movably guided on a rod (5) and acted upon by a preloading force in the direction of the mould box (30) and which, facing the mould box, has a connection opening surrounded by a seal (35) and between the latter and a low pressure connection (3), comprises a valve (10) which is formed by a valve seat (9) in the valve body (2) and a valve disc (8) carried by the rod (5), which is held closed by the preloading force and which opens upon a relative movement of the valve body (2) with respect to the rod (5) caused by the coupling being pressed against the mould box (30) and directed counter to the preloading force, characterised in that a piston (17) operating in a pressure medium cylinder (19) is connected to the rod (5) and that by pressure medium acting on at least one face of the piston the rod (5), together with the valve body (2), can be moved towards the mould box (30) or away therefrom.

Description

Die Erfindung betrifft eine Unterdruckkupplung für den Anschluß von Formkästen für vakuumverfestigte Gießformen an ein Unterdrucknetz, mit einem auf einer Stange beweglich geführten und durch eine Vorspannkraft in Richtung auf den Formkasten beaufschlagten Ventilkörper, der dem Formkasten zugewendet eine von einer Dichtung umgebene Anschlußöffnung aufweist und zwischen dieser und einem Unterdruckanschluß ein Ventil enthält, das von einem Ventilsitz im Ventilkörper und einem von der Stange getragenen Ventilteller gebildet ist, durch die Vorspannkraft geschlossen gehalten wird und bei einer durch das Andrücken der Kupplung an den Formkasten verursachten, gegen die Vorspannkraft gerichteten Relativbewegung des Ventilkörpers bezüglich der Stange öffnet.The invention relates to a vacuum coupling for the connection of mold boxes for vacuum-hardened casting molds to a vacuum network, with a valve body movably guided on a rod and acted upon by a prestressing force in the direction of the mold box, which valve body has a connection opening surrounded by a seal and between the latter and a negative pressure connection contains a valve, which is formed by a valve seat in the valve body and a valve plate carried by the rod, is kept closed by the pretensioning force and, in relation to the pretensioning force, results in a relative movement of the valve body with respect to the pretensioning force, caused by the pressing of the coupling the rod opens.

Bei vakuumverfestigten Gießformen wird die Formbeständigkeit durch den im Inneren der Gießform, d. h. in der Formmasse, erzeugten Unterdruck erhalten. Dieser Unterdruck muß bei der Herstellung der. Gießform, beim Transport, beim Abgießen und auch beim anschließenden Erkalten des Gußstückes stets aufrechterhalten werden, da andernfalls die Formmasse ihren verfestigten Zustand verliert. Da die einzelnen Verarbeitungsplätze sehr weit auseinander liegen können, muß die Gießform an die jeweils an den einzelnen Arbeitsplätzen befindlichen Unterdruckanschlüsse angeschlossen werden, was entweder durch einfaches Aufstecken von Schläuchen von Hand oder aber durch mechanisch betätigte Kupplungen in Verbindung mit Ventilsteuerungen erreicht werden kann. Dieses Umkuppeln kommt relativ häufig vor, wobei jedesmal die Gießform auf der Transporteinrichtung an ein neues Unterdrucksystem angekuppelt werden muß, während der alte Anschluß gelöst wird, worauf wiederum am Bestimmungsort der neue Anschluß fertiggestellt und der Anschluß der Transporteinrichtung gelöst werden muß. Dieser Vorgang erfolgt bei der Formherstellung, beim Abgießen, beim Abkühlen und wiederum beim Transport zur Auspackstelle.In the case of vacuum-strengthened casting molds, the dimensional stability is determined by the inside of the casting mold, i.e. H. obtained in the molding compound, generated negative pressure. This negative pressure must be used to manufacture the. The casting mold, during transport, during pouring and also when the casting cools down, must always be maintained, since otherwise the molding compound loses its solidified state. Since the individual processing stations can be very far apart, the mold must be connected to the vacuum connections located at the individual workplaces, which can be achieved either by simply attaching hoses by hand or by mechanically operated couplings in connection with valve controls. This coupling occurs relatively frequently, each time the mold on the transport device must be coupled to a new vacuum system while the old connection is being loosened, whereupon the new connection must be completed at the destination and the connection of the transport device must be disconnected. This process takes place during mold production, pouring, cooling and again during transport to the unpacking point.

In der älteren nicht vorveröffentlichten DE-A-3039394 ist eine automatisch arbeitende Unterdruckkupplung der vorstehend genannten Art bekannt, die ein automatisches Ankoppeln der Gießform an das Vakuumnetz gestattet. Bei dieser Unterdruckkupplung ist es allerdings erforderlich, daß die Gießform auf den Ventilkörper der Unterdruckform aufgesetzt wird, so daß dieser durch das Gewicht der Gießform belastet wird und entgegen einer Federkraft relativ zu einer den Ventilteller tragenden Stange verschoben wird. Hierdurch wird das Ventil in der Unterdruckkupplung geöffnet und die Verbindung des Unterdrucknetzes zur Gießform hergestellt. Die für den Anschluß der Gießform an das Unterdrucknetz erforderliche Relativbewegung von Gießform und Unterdruckkupplung ist in bestimmten Anwendungsfällen nicht zu erhalten.In the older, unpublished DE-A-3039394, an automatically operating vacuum coupling of the aforementioned type is known, which allows the casting mold to be automatically coupled to the vacuum network. With this vacuum coupling, however, it is necessary that the casting mold is placed on the valve body of the vacuum mold, so that the latter is loaded by the weight of the casting mold and is displaced against a spring force relative to a rod carrying the valve disk. This opens the valve in the vacuum coupling and connects the vacuum network to the casting mold. The relative movement of the casting mold and the vacuum coupling required for the connection of the casting mold to the vacuum network cannot be obtained in certain applications.

Auch eine aus DE-A-2710481 bekannte Unterdruckkupplung für Vakuumformkästen ist ortsfest angeordnet, und der Formkasten muß so nahe an die Unterdruckkupplung heranbewegt werden, bis der dazwischen verbliebene Spalt so klein geworden ist, daß der angelegte Unterdruck ausreicht, um das Ventil entgegen der Kraft einer Rückholfeder über eine geringe Strecke an die Wand des Formkastens angesaugt wird. Diese Arbeitsweise ist mit einer beträchtlichen Funktionsunsicherheit und mit einem erheblichen Vakuumverlust verbunden.A vacuum coupling for vacuum molding boxes known from DE-A-2710481 is also arranged in a stationary manner, and the molding box must be moved so close to the vacuum coupling until the gap remaining between them has become so small that the vacuum applied is sufficient to counter the force against the valve a return spring is sucked onto the wall of the molding box over a short distance. This way of working is associated with considerable functional uncertainty and with a considerable loss of vacuum.

Aus DE-A-24 07 264 - ist eine Unterdruckkupplung für den Anschluß an Formkästen an ein Unterdrucknetz bekannt, die mittels eines Druckmittel betätigten Kolbens an die Anschlußöffnung des Unterdruckkastens heranbewegt und angedrückt wird, so daß der Formkasten nicht selbst an die Kupplung heranbewegt oder auf diese aufgesetzt werden muß. Diese bekannte Kupplung hat jedoch kein beim Ankuppeln automatisch betätigtes Ventil, sondern einerseits muß am Formkasten ein Rückschlagventil vorgesehen sein und anderseits muß, wenn das Unterdrucknetz nicht ständig zur Atmosphäre offen sein soll, der Kupplung ein gesondert betätigbares Absperrorgan vorgeschaltet sein.From DE-A-24 07 264 - a vacuum coupling for connection to molded boxes to a vacuum network is known, which is moved by means of a pressure-actuated piston to the connection opening of the vacuum box and pressed so that the molded box itself does not move towards or onto the coupling this must be put on. However, this known coupling has no automatically actuated valve when coupling, but on the one hand a check valve must be provided on the molding box and on the other hand, if the vacuum network is not to be constantly open to the atmosphere, the coupling must be preceded by a separately operable shut-off device.

Der Erfindung liegt die Aufgabe zugrunde, eine Unterdruckkuplung der eingangs genannten Art, d. h. mit beim Ankuppeln automatisch sich öffnendem Ventil zu schaffen, die eine einfache und platzsparende Bauweise hat und das Herstellen der Verbindung zwischen Gießform und Unterdrucknetz ermöglicht, ohne daß die Gießform eine Aufsetz- oder Ankupplungsbewegung zur Kupplung hin ausführen muß.The invention has for its object a vacuum clutch of the type mentioned, d. H. to create with valve automatically opening when coupling, which has a simple and space-saving design and enables the connection between the mold and vacuum network, without the mold having to perform a mounting or coupling movement to the coupling.

Zur Lösung der Aufgabe ist eine Unterdruckkupplung der eingangs genannten Art gemäß der Erfindung dadurch gekennzeichnet, daß mit der Stange ein in einem Druckmittelzylinder arbeitender Kolben verbunden ist und daß durch Druckmittelbeaufschlagung mindestens der einen Kolbenseite die Stange unter Mitnahme des Ventilkörpers gegen den Formkasten oder von ihm weg bewegbar ist.To achieve the object, a vacuum clutch of the type mentioned according to the invention is characterized in that a piston working in a pressure medium cylinder is connected to the rod and that by applying pressure medium to at least one side of the piston, the rod takes the valve body against the molding box or away from it is movable.

Hierdurch wird der Vorteil erreicht, daß durch die bloße Beaufschlagung des Kolbens mit Druckmittel zuerst der Ventilkörper mittels der Stange auch über eine beträchtliche Strecke an den Formkasten heranbewegt und an ihn angedrückt werden kann, und daß dann selbsttätig im Verlauf dieser Andrückbewegung, wenn der druckdichte Anschluß des Ventilgehäuses an die Gießform bereits hergestellt ist, die Öffnung des Ventils und damit die Freigabe des Unterdrucks zur Gießform erfolgt.This has the advantage that by simply applying pressure to the piston with pressure medium, the valve body can first be moved and pressed against the molding box over a considerable distance by means of the rod, and then automatically in the course of this pressing movement when the pressure-tight connection of the valve housing to the casting mold is already made, the opening of the valve and thus the release of the negative pressure to the casting mold takes place.

Vorzugsweise ist der Druckmittelzylinder als ein doppelt wirkender Druckmittelzylinder mit Druckmittelzuführung wahlweise zur einen oder anderen Kolbenfläche des Kolbens ausgebildet, um sowohl das Heranführen als auch das Wegbewegen der Kupplung relativ zum Gießkasten durch Druckmittelbeaufschlagung durchführen zu können. Wahlweise ist es aber auch möglich, lediglich das Heranführen der Kupplung an den Gießkasten durch Druckmittelbeaufschlagung und das Abziehen der Kupplung durch eine Rückstellfeder vorzunehmen.The pressure medium cylinder is preferably a double-acting pressure medium cylinder Pressure medium supply optionally designed for one or the other piston surface of the piston, in order to be able to carry out both the approaching and the moving away of the coupling relative to the casting box by applying pressure medium. Alternatively, however, it is also possible to simply bring the coupling closer to the casting box by applying pressure medium and pulling the coupling off using a return spring.

Gemäß einer bevorzugten weiteren Ausgestaltung der Erfindung ist vorgesehen, daß der Ventilkörper mit einem in den Druckmittelzylinder tauchenden Ringkolbenteil versehen ist, und daß die das Ventil geschlossen haltende Vorspannkraft durch ein in den Zylinderraum zwischen dem Ringkolbenteil des Ventilkörpers und der diesen zugewendeten Kolbenfläche des Kolbens der Stange zugeführtes Druckmittel erzeugt wird. Hierdurch wird erreicht, daß nicht nur die Andrückkraft zum Andrücken der Kupplung an den Gießkasten, sondern auch die Vorspannkraft, die das Ventil zunächst geschlossen hält, durch das Druckmittel erzeugt wird und somit eine gesonderte Feder zum Erzeugen der Vorspannkraft nicht erforderlich ist.According to a preferred further embodiment of the invention, it is provided that the valve body is provided with an annular piston part immersed in the pressure medium cylinder, and that the biasing force holding the valve closed is provided by a piston space in the cylinder space between the annular piston part of the valve body and the piston surface of the rod facing the latter supplied pressure medium is generated. This ensures that not only the pressing force for pressing the coupling to the casting box, but also the pretensioning force, which initially keeps the valve closed, is generated by the pressure medium and thus a separate spring is not required to generate the pretensioning force.

Die Unterdruckkupplung wird durch den doppelt wirkenden Druckzylinder betätigt, wobei die dem Ventilkörper benachbarte Zylinderkammer des Druckzylinders ständig mit einem bestimmten Druck beaufschlagt ist, während die andere Seite des Druckzylinders nur bei Betätigung der Unterdruckkupplung mit einem Druck beaufschlagt wird, der dem Druck in der ersten Zylinderkammer entspricht. Der Kolben des Druckzylinders ist als Differenzkolben ausgebildet, so daß bei gleichem Druck auf beiden Seiten des Kolbens dieser sich in Richtung des Ventilkörpers bewegt. Da jedoch der Ventilkörper gleichfalls in den einen Zylinderraum eintaucht und durch das Druckmedium in Achsrichtung beaufschlagt wird, findet so lange keine relative Verschiebung zwischen dem Kolben und dem Ventilkörper statt, bis dessen Anlagefläche an der Gießform anliegt.The vacuum clutch is actuated by the double-acting pressure cylinder, the cylinder chamber of the pressure cylinder adjacent to the valve body being constantly subjected to a certain pressure, while the other side of the pressure cylinder is only pressurized when the vacuum clutch is actuated, which pressure corresponds to the pressure in the first cylinder chamber corresponds. The piston of the pressure cylinder is designed as a differential piston, so that the same pressure on both sides of the piston moves in the direction of the valve body. However, since the valve body is also immersed in one cylinder chamber and acted upon by the pressure medium in the axial direction, there is no relative displacement between the piston and the valve body until its contact surface rests on the casting mold.

Erst wenn dieser druckdichte Anschluß hergestellt ist, kann der Kolben relativ zum Ventilkörper verschoben'werden und damit auch die den Ventilteller tragende Stange. Das Ventil der Unterdruckkupplung kann somit erst geöffnet werden, wenn der druckdichte Anschluß mit der Gießform hergestellt ist.Only when this pressure-tight connection has been established can the piston be displaced relative to the valve body and thus also the rod carrying the valve disk. The valve of the vacuum coupling can therefore only be opened when the pressure-tight connection with the casting mold has been established.

Diese Ausführungsform hat den Vorteil, daß das Ausfahren der Stange durch Betätigen des Druckzylinders auch bereits dann erfolgen kann, wenn sich der Formkasten noch nicht an seiner Stelle befindet. Durch Beaufschlagung beider Druckkammern mit dem gleichen Druck nimmt der Kolben die oberste bzw. ausgefahrene Stellung ein, ohne daß eine Relativbewegung zwischen Ventilkörper und Stange auftritt. Das Ventil bleibt also auch dann solange geschlossen, bis die Gießform an ihre Stelle gebracht wird. Erst bei Belastung des Ventilkörpers durch die Gießform wird der Ventilkörper zum Druckzylinder hin verschoben, so daß das Ventil sich öffnen kann.This embodiment has the advantage that the rod can be extended by actuating the pressure cylinder even when the molding box is not yet in its place. By applying the same pressure to both pressure chambers, the piston assumes the uppermost or extended position without any relative movement between the valve body and the rod. The valve remains closed until the mold is put in its place. Only when the valve body is loaded by the casting mold is the valve body moved towards the pressure cylinder so that the valve can open.

Weitere vorteilhafte Ausgestaltungen der Erfindung gehen aus den Ansprüchen in Verbindung mit Beschreibung und Zeichnungen hervor.Further advantageous embodiments of the invention emerge from the claims in conjunction with the description and drawings.

Ein Ausführungsbeispiel der Erfindung ist in den Figuren dargestellt. In dieser zeigen :

  • Figur 1 einen Längsschnitt durch eine erfindungsgemäß ausgebildete Unterdruckkupplung mit geschlossenem Ventil und
  • Figur 2 den gleichen Schnitt in der Stellung, in der über die Unterdruckkupplung eine Verbindung zum Unterdrucknetz hergestellt ist.
An embodiment of the invention is shown in the figures. In this show:
  • 1 shows a longitudinal section through a vacuum clutch designed according to the invention with the valve closed and
  • Figure 2 shows the same section in the position in which a connection to the vacuum network is made via the vacuum coupling.

Die in den Fig. 1 und 2 im Schnitt dargestellte Unterdruckkupplung 1 besteht aus einem Ventilkörper 2, der in einen Druckzylinder 19 eintaucht und dicht in dessen Zylinderkopf 15 geführt ist. Der Ventilkörper 2 hat einen Unterdruckanschluß 3, an dem die vom Unterdrucknetz kommende und nicht dargestellte Leitung anschließbar ist. Der Ventilkörper 2 ist mit einer Bohrung 6 versehen, in der eine Stange 5 gleitet, die mittels einer Dichtung 7 in der Bohrung abgedichtet ist. Das Ende 13 des Ventilkörpers ist als Ringkolben ausgebildet und in dem Zylinderkopf 15 des Druckzylinders 19 geführt und mittels einer Dichtung 16 abgedichtet.The vacuum clutch 1 shown in FIGS. 1 and 2 in section consists of a valve body 2, which is immersed in a pressure cylinder 19 and is guided tightly in its cylinder head 15. The valve body 2 has a vacuum connection 3, to which the line coming from the vacuum network and not shown can be connected. The valve body 2 is provided with a bore 6 in which a rod 5 slides, which is sealed by means of a seal 7 in the bore. The end 13 of the valve body is designed as an annular piston and guided in the cylinder head 15 of the pressure cylinder 19 and sealed by means of a seal 16.

Im oberen Bereich des Ventilkörpers 2 ist ein Ventil 10 ausgebildet, das einen ringförmigen Ventilsitz 9 aufweist, der sich in einer Ebene senkrecht zur Stange 5 erstreckt. Am Ende der Stange 5 ist ein Ventilteller 8 mit einer Ringdichtung 11 angeordnet, die mit dem Ventilsitz 9 zusammenwirkt.In the upper region of the valve body 2, a valve 10 is formed which has an annular valve seat 9 which extends in a plane perpendicular to the rod 5. At the end of the rod 5, a valve plate 8 is arranged with an annular seal 11, which cooperates with the valve seat 9.

Der Ventilkörper 2 bildet an seinem freien Ende eine ringförmige Dichtfläche 34, die mit einer Ringdichtung 35 versehen ist. Diese Ringdichtung hat einen Abstand zum Ventil 10, und zwar einen solchen Abstand, daß die Verschiebung des Ventiltellers 8 innerhalb des Ventilkörpers 2 erfolgt.The valve body 2 forms at its free end an annular sealing surface 34 which is provided with an annular seal 35. This ring seal is at a distance from the valve 10, namely such a distance that the displacement of the valve plate 8 takes place within the valve body 2.

Der Druckzylinder 19 ist als doppelt wirkender Zylinder ausgebildet und hat zwei Druckmittelanschlüsse 21 und 27. Der Zylinderkopf 15 und der Zylinderboden 20 sind über ein Rohr 36 miteinander verbunden und mittels Dichtungen 37 gegenüber diesen abgedichtet. Der im Druckzylinder 19 angeordnete Kolben 17, der fest mit der Stange 5 verbunden ist, ist bekannterweise mittels Dichtringen 18 gegenüber dem Rohr 36 abgedichtet. Die Länge des als Ringkolben ausgebildeten Teiles 13 des Ventilkörpers 2 ist so bemessen, daß bei maximaler Verschiebung des Kolbens 17 dieses noch ausreichend im Zylinderkopf 15 geführt und abgedichtet ist.The pressure cylinder 19 is designed as a double-acting cylinder and has two pressure medium connections 21 and 27. The cylinder head 15 and the cylinder base 20 are connected to one another via a tube 36 and sealed with respect to them by means of seals 37. The piston 17 arranged in the pressure cylinder 19, which is fixedly connected to the rod 5, is known to be sealed with respect to the tube 36 by means of sealing rings 18. The length of the part 13 of the valve body 2, which is designed as an annular piston, is dimensioned such that, when the piston 17 is displaced to the maximum extent, it is sufficiently guided and sealed in the cylinder head 15.

Die Arbeitsweise der erfindungsgemäßen Unterdruckkupplung ist folgende. Der Zylinderraum 14 ist ständig über den Anschluß 21 an eine Druckmittelquelle angeschlossen, so daß in diesem ein konstanter Druck aufrechterhalten wird. Dieser Druck wird zum einen auf die Ringfläche 22 des Kolbens 17 und zum anderen auf die Ringfläche 23 des Ringkolbens 13, der Teil des Ventilkörpers 2 ist, ausgeübt. Kolben 17 und Ringkolben 13 werden somit durch den herrschenden Druck in entgegengesetzte Richtungen bewegt, so daß hierdurch die Stange 5 in Richtung 24 bewegt wird und so das Ventil 10 schließt. Die Größe der Schließkraft des Ventiles 10 ist somit abhängig von der Größe der Ringfläche 23. Da der Zylinderraum 26 drucklos ist, wird sich der Kolben 17 in Richtung 24 verschieben, wie dies in Fig. 1 dargestellt ist, und zwar solange, bis der Ventilkörper 2, der durch den Ventilteller 8 mitgenommen wird, mit seiner Schulter am Zylinderkopf 15 anliegt.The operation of the vacuum clutch according to the invention is as follows. The cylinder chamber 14 is continuously connected via the connection 21 to a pressure medium source, so that a constant pressure is maintained in this. This pressure is exerted on the one hand on the annular surface 22 of the piston 17 and on the other hand on the annular surface 23 of the annular piston 13, which is part of the valve body 2. Pistons 17 and Annular pistons 13 are thus moved in opposite directions by the prevailing pressure, so that the rod 5 is thereby moved in the direction 24 and the valve 10 closes. The magnitude of the closing force of the valve 10 is thus dependent on the size of the annular surface 23. Since the cylinder space 26 is depressurized, the piston 17 will shift in the direction 24, as shown in FIG. 1, until the valve body 2, which is carried by the valve plate 8, rests with its shoulder on the cylinder head 15.

Soll über die Unterdruckkupplung 1 eine Gießform 30 an das Unterdrucknetz angeschlossen werden, so wird der Zylinderraum 26 über den Anschluß 27 mit dem gleichen Druck beaufschlagt, der auch im Zylinderraum 14 herrscht. Da die Kolbenfläche 28 im Zylinderraum 26 um die Fläche der Stange 5 größer ist als die Ringfläche 22 im Zylinderraum -14, bewegt sich der Kolben 17 in Richtung 25. Der Abstand des Kolbens 17 zur Ringfläche 23 des Ventilkörpers 2 ändert sich jedoch nicht, da der Ringkolben 13 durch den im Zylinderraum 14 herrschenden Druck gleichfalls in Richtung 25 verschoben wird. Der relative Abstand vom Ringkolben 13 verändert sich erst dann, wenn die Dichtfläche 34 zur Anlage an der Gießform 30 gelangt. Dies hat zur Folge, daß der Ventilteller 8 sich vom Ventilsitz 9 abhebt und so die Verbindung zwischen dem Unterdrucknetz und dem Ventilausgang erhalten wird. Zuerst wird der Raum 31 vor dem Rückschlagventil 32 der Gießform evakuiert. Ist dieser Druck niedriger geworden als der Druck im Inneren der Gießform, so öffnet sich das Rückschlagventil 32, so daß nunmehr der Druck in der Gießform über das Ventil 10 abgesenkt werden kann. Dieser Vorgang ist in Fig. 2 dargestellt, wobei gleiche Teile mit gleichen Bezugszeichen versehen sind.If a casting mold 30 is to be connected to the vacuum network via the vacuum coupling 1, the cylinder chamber 26 is pressurized via the connection 27 with the same pressure that also prevails in the cylinder chamber 14. Since the piston area 28 in the cylinder space 26 is larger by the area of the rod 5 than the ring area 22 in the cylinder space -14, the piston 17 moves in the direction 25. The distance of the piston 17 from the ring area 23 of the valve body 2 does not change, however the annular piston 13 is also displaced in the direction 25 by the pressure prevailing in the cylinder space 14. The relative distance from the annular piston 13 changes only when the sealing surface 34 comes to rest on the casting mold 30. This has the consequence that the valve plate 8 stands out from the valve seat 9 and the connection between the vacuum network and the valve outlet is thus obtained. First, the space 31 in front of the check valve 32 of the mold is evacuated. If this pressure has become lower than the pressure inside the casting mold, the check valve 32 opens so that the pressure in the casting mold can now be reduced via the valve 10. This process is shown in Fig. 2, wherein the same parts are provided with the same reference numerals.

"Eine Unterdruckkupplung gemäß der Erfindung kann in beliebiger Lage eingebaut werden und benötigt auch nicht, daß die Gießform gegen die Unterdruckkupplung bewegt werden muß, damit das Unterdruckventil 10 geöffnet wird."A vacuum clutch according to the invention can be installed in any position and also does not require that the mold must be moved against the vacuum clutch so that the vacuum valve 10 is opened.

Für die Ablösung der Unterdruckkupplung von der Gießform 30 muß lediglich der Druck in dem Zylinderraum 26 aufgehoben werden. Der Kolben 17 und damit die Stange 5 bewegt sich durch den im Zylinderraum 14 noch herrschenden Druck zum Zylinderboden 20 hin, so daß zunächst das Ventil 10 geschlossen wird. Anschließend nimmt die Stange 5 über dem Ventilteller 10 den Ventilkörper mit, so daß dieser wieder in seine Ausgangsstellung gelangt.To detach the vacuum coupling from the mold 30, only the pressure in the cylinder space 26 has to be released. The piston 17 and thus the rod 5 moves towards the cylinder base 20 due to the pressure still prevailing in the cylinder chamber 14, so that the valve 10 is first closed. Subsequently, the rod 5 takes the valve body over the valve plate 10, so that it returns to its initial position.

Claims (4)

1. A low pressure coupling for the connection to an low pressure system of mould boxes for moulds compacted under vacuum with a valve body (2) which is movably guided on a rod (5) and acted upon by a preloading force in the direction of the mould box (30) and which, facing the mould box, has a connection opening surrounded by a seal (35) and between the latter and a low pressure connection (3), comprises a valve (10) which is formed by a valve seat (9) in the valve body (2) and a valve disc (8) carried by the rod (5), which is held closed by the preloading force and which opens upon a relative movement of the valve body (2) with respect to the rod (5) caused by the coupling being pressed against the mould box (30) and directed counter to the preloading force, characterised in that a piston (17) operating in a pressure medium cylinder (19) is connected to the rod (5) and that by pressure medium acting on at least one face of the piston the rod (5), together with the valve body (2), can be moved towards the mould box (30) or away therefrom.
2. A low pressure coupling according to Claim 1, characterised in that the pressure medium cylinder (19) is a double-acting pressure medium cylinder with pressure medium being fed optionally to one or other piston face (22, 28) of the piston (17).
3. A low pressure coupling according to Claim 1 or 2, characterised in that the valve body (2) is provided with an annular piston part (13) entering the pressure medium cylinder (19), and that the preloading force holding the valve (10) closed is created by a pressure medium fed into the cylinder chamber (14) between the annular piston part (13) of the valve body (2) and the piston face (22), facing the latter, of the piston (17) of the rod (5).
4. A low pressure coupling according to Claim 3, characterised in that the cylinder chamber (14) is constantly acted upon by pressure medium and the effective piston area (22), facing the valve body (2), of the piston (17) connected to the rod (5) is greater than the effective piston area of the annular piston part (13) of the valve body (2).
EP82108197A 1981-11-06 1982-09-06 Low-pressure connection for moulds consolidated under vacuum Expired EP0078897B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82108197T ATE19211T1 (en) 1981-11-06 1982-09-06 VACUUM CLUTCH FOR VACUUM CONSOLIDATED MOLDS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3144118 1981-11-06
DE19813144118 DE3144118A1 (en) 1981-11-06 1981-11-06 VACUUM COUPLING FOR VACUUM-CONTAINED CASTING MOLDS

Publications (2)

Publication Number Publication Date
EP0078897A1 EP0078897A1 (en) 1983-05-18
EP0078897B1 true EP0078897B1 (en) 1986-04-16

Family

ID=6145785

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82108197A Expired EP0078897B1 (en) 1981-11-06 1982-09-06 Low-pressure connection for moulds consolidated under vacuum

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EP (1) EP0078897B1 (en)
AT (1) ATE19211T1 (en)
DE (2) DE3144118A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3345598A1 (en) * 1983-12-16 1985-06-27 Heinrich Wagner Sinto Maschinenfabrik GmbH, 5928 Laasphe Reduced pressure coupling
DK489886A (en) * 1986-10-14 1988-04-15 Dansk Ind Syndikat PLANT WITH A POWER-DRIVEN GRIBER AND NUMBER OF GRIBE OBJECTS, NECESSARY FOR USE IN AN AUTOMATED SUBSTANCES, WITH A FLUID DUMP BETWEEN THE GRIBER AND A GRAB GOVERNED OBJECT

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3825058A (en) * 1972-04-15 1974-07-23 Sintokogio Ltd Mold prepared by vacuum sealed molding process
DE2407264C2 (en) * 1974-02-15 1975-07-17 Heinrich Wagner, Maschinenfabrik, 5928 Laasphe Device for making and moving casting molds
JPS5440419Y2 (en) * 1976-03-15 1979-11-28
DE3039394A1 (en) * 1980-10-18 1982-05-06 Heinrich Wagner Maschinenfabrik GmbH & Co, 5928 Laasphe VACUUM CONNECTION FOR VACUUM-CONTAINED CASTING MOLDS

Also Published As

Publication number Publication date
DE3144118A1 (en) 1983-05-19
ATE19211T1 (en) 1986-05-15
DE3144118C2 (en) 1989-09-21
EP0078897A1 (en) 1983-05-18
DE3270639D1 (en) 1986-05-22

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