EP0166228B1 - Installation for carrying out a full-mould casting process - Google Patents

Installation for carrying out a full-mould casting process Download PDF

Info

Publication number
EP0166228B1
EP0166228B1 EP85106440A EP85106440A EP0166228B1 EP 0166228 B1 EP0166228 B1 EP 0166228B1 EP 85106440 A EP85106440 A EP 85106440A EP 85106440 A EP85106440 A EP 85106440A EP 0166228 B1 EP0166228 B1 EP 0166228B1
Authority
EP
European Patent Office
Prior art keywords
moulding
base plate
boxes
molding
compressed air
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
EP85106440A
Other languages
German (de)
French (fr)
Other versions
EP0166228A3 (en
EP0166228A2 (en
Inventor
Fridolin Bissinger
Erich Krzyzanowski
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.)
Saint Gobain Isover G+H AG
Original Assignee
Gruenzweig und Hartmann und Glasfaser AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gruenzweig und Hartmann und Glasfaser AG filed Critical Gruenzweig und Hartmann und Glasfaser AG
Priority to AT85106440T priority Critical patent/ATE36476T1/en
Publication of EP0166228A2 publication Critical patent/EP0166228A2/en
Publication of EP0166228A3 publication Critical patent/EP0166228A3/en
Application granted granted Critical
Publication of EP0166228B1 publication Critical patent/EP0166228B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C21/00—Flasks; Accessories therefor
    • B22C21/01—Flasks; Accessories therefor for vacuum-sealed moulding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C11/00—Moulding machines characterised by the relative arrangement of the parts of same
    • B22C11/02—Machines in which the moulds are moved during a cycle of successive operations
    • B22C11/04—Machines in which the moulds are moved during a cycle of successive operations by a horizontal rotary table or carrier
    • 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
    • B22C9/04—Use of lost patterns
    • B22C9/046—Use of patterns which are eliminated by the liquid metal in the mould
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D47/00—Casting plants
    • B22D47/02—Casting plants for both moulding and casting

Definitions

  • the invention relates to a device for carrying out the full mold casting process with several mold boxes, in which gasified models are surrounded by granular molding material under the influence of poured melt, which is loosened with compressed air when molding the models and when the castings are removed from the mold and solidified under vacuum during the casting process, wherein each molding space of the molding box is connected via these at least partially delimiting partition walls with chambers for the gaseous working media, and in which the molding box can be moved to a plurality of work stations forming a closed work system with a rotating, intermittently controlled means of transport.
  • Such a device is known from CH-A-524415.
  • the molding boxes used in this known device each have a one-piece base plate made of porous sintered metal, which divides the molding space of the molding box filled with molding material from an underlying prechamber, which can be acted upon alternately with compressed air or with a vacuum at the individual work stations.
  • a device for carrying out the full molding process in which a molding box provided with a gas-permeable base plate is used, in which the side walls are also designed to be gas-permeable.
  • the majority of the combustion gases generated during casting are to be removed via the gas-permeable side walls provided here, so that only small amounts of hot gases can get into the vacuum pump via the base plate.
  • the base plate made of sintered metal has a comparatively low flow resistance, so that the flow resistance of the compressed air which rises overall in the molding space is determined primarily by the flow resistance of the molding material. If the molding material is present at different bed heights in the molding space at the beginning of the compressed air supply, the imported compressed air searches for the path of least resistance, e.g. B. in the region of a depression of the surface of the molding material, while molding material accumulations in the molding space are no longer flowed through in a sufficient manner to form the fluidized bed. In addition, there are confusing flow conditions in the base plate as a result of locally different flow resistances, in particular after a long period of use, if, for example, deposits in the sintered material of the base plate cause gases to flow through them.
  • the invention comes in, which is based on the object of creating a device for carrying out the full mold casting process, with which it is possible to produce medium-sized castings, such as, for. B. cylinder heads of water-cooled four-cylinder automotive engines or cast grapes, largely automated economically to produce by the full mold casting process, at the same time a complete whirling of the molding material must be guaranteed when the compressed air is introduced even with a long period of operation.
  • each work step can be precisely defined at the individual work stations. Furthermore, there is no danger that the gas-permeable partition walls used in connection with the production of a fluidized bed will clog after a short time; the latter also means that the intensity of the loosening of the molding material remains precisely controllable in the long term, thus ensuring reliable automation.
  • This in turn has the advantage that the molding material can remain in the molding box after the casting has been removed from the mold, since it can be cooled in a simple manner at several workstations by blowing in compressed air again.
  • the mold boxes therefore do not have to be completely emptied as usual after demolding, so that it is sufficient to connect them stationary to the means of transport, i.e. an automatic tilting device for the mold boxes can be saved. It should also be emphasized that with a stationary arrangement, the dust that otherwise arises when the molding box is dumped is advantageously not produced here.
  • a suction device is provided for the partial removal of the molding material from the molding box.
  • a further significant improvement of the device according to the preamble of claim 4 takes place in that a perforated plate with a flow resistance which is preferably higher than the base plate is provided below the bottom plate of each molding box.
  • a perforated plate with a flow resistance which is preferably higher than the base plate is provided below the bottom plate of each molding box.
  • the device for carrying out the full molding process essentially consists of a rotary system serving as a means of transport 1, which forms a closed system in the sense of the work steps. It has a stand 3 resting on a base plate 2, on which a turntable 5 is rotatably mounted with a bearing ring 4. In the present example, nine molding boxes are stationary on the turntable 5 at the same distance, i. H. not fixed tiltable.
  • a drive shaft 7 of an electric motor 8 meshes with a non-rotatable ring gear 9 of the turntable 5.
  • the electric motor 8 the rotary movement of the turntable 5 is controlled intermittently by control means, not shown, in such a way that one Molding box 6 at the work stations labeled A to J in FIG. 1 makes timed stops.
  • the molding steps are carried out, i. H. Create a fluidized bed, then fill the remaining molding material into the molding box and finally pour.
  • the filling takes place with the aid of a filling device, not shown, which is symbolized by the arrow 10.
  • the work steps solidify, but the number can be expanded.
  • the step of demolding i.e. H. Whirling up the molding material and removing the casting, carried out, in which case the step of partially removing the molding material from the molding box also takes place here.
  • a suction device 11 symbolized by the arrow 11 is used, which can work in a known manner on the principle of a vacuum cleaner.
  • Each molding box 6 has a circular cross section and an inner molding space 12 for receiving the granular molding material 13, which in the present case consists of binder-free sand.
  • the molding material 13 is filled into the molding space 12 through an upper opening 14 and rests on the underside of the molding space 12 on a base plate 15 which forms a partition.
  • a pre-chamber 16 with a connection 17 for the supply of compressed air according to arrow 18 is provided below the molding space 12 or the base plate 15.
  • the compressed air flowing into the pre-chamber 16 is present on the underside of the base plate 15.
  • the base plate 15 is designed to be gas-permeable, so that the compressed air present penetrates through the base plate 15 into the mold space 12 and the mold space 12 there Swirl molding material 13, so that a fluidized or fluidized bed is formed.
  • the compressed air passes through the base plate 15, which is made of sintered metal, for example, when it forms the sole separation between the molding space 12 and the pre-chamber 16, in a very different local flow.
  • Such differences in the flow through the base plate 15 can result from locally different flow resistances of the sintered material, and in particular from locally different pouring heights of the molding material 13 in the molding space 12. Accumulations of the molding material 12 in the molding space 12 become due to the higher flow resistance of the compressed air only in one Fluidization no longer flows through sufficient intensity, so that the full formation of the fluidized bed is hindered.
  • a perforated plate 19 for example made of metal, is therefore arranged below the base plate 15 and has holes 20 for the passage of air.
  • the flow resistance of the perforated plate 19 with the holes 20 is relatively high overall; in any case higher than the flow resistance that is present in the base plate 15, which is made of sintered material, for example.
  • the perforated plate 19 thus forms the main flow resistance for the compressed air in the pre-chamber 16 and forms, so to speak, a throttle in front of which a relatively high supply pressure builds up over the surface of the perforated plate 19, which has a height of, for example, up to 0.5 MPa (5 bar) can have.
  • the supply pressure on the underside of the perforated plate 19 presses the compressed air through the holes 20 in discrete flows, which thus act in a similar manner to nozzles, so that the underside of the bottom plate 15 is flowed towards in the manner indicated by arrows 21 in FIG. 4. If the base plate 15 were now missing and the core flow directly into the molding material 13 according to arrows 21, this would result in a speed profile of the inflowing compressed air, as is illustrated in FIG. 4 by a dash-dotted line 22 and corresponding speed arrows 23.
  • the combination of base plate 15 / perforated plate 19 eliminates this disadvantage of so-called “bubbling”, and advantageously a uniform speed profile of the compressed air flowing into the molding material 13 is obtained, as is also shown in FIG. 4 with the dashed line 24 and corresponding speed arrows 25 .
  • the holes 20 provided in this connection have a diameter between approximately 2 and 6 mm, preferably between 3 and 5 mm and in the illustrated example case of 4 mm. They are at a mutual distance of several cm, preferably between 3 and 5 cm, in the example at a distance of 4 cm.
  • the considerable supply pressure lies in the antechamber 16, so that spacers 26 are provided for the rear support of the perforated plate 19, which are arranged in a grid-like manner in the example and thus form a flat-looking rear support for the perforated plate 19.
  • the spacers 26 arranged in a grid-like manner each delimit square chambers 27, a hole 20 of the perforated plate 19 being assigned to a chamber 27 in the center.
  • the fact that the spacers 26 largely seal the adjacent chambers 27 against one another ensures in particular that the compressed air per chamber 27 exits evenly through the base plate 15, so that the uniform flow profile 24 is obtained.
  • the molding material 13 located in the molding space 12 is fluidized in the manner described by compressed air supply according to arrow 18.
  • the molding material 13 behaves essentially like a liquid, so that a model made of expanded polystyrene, as is customary in full mold casting, can be introduced through the opening 14 easily and without damage into and from the fluidized molding material 13 complicated undercuts or the like is completely washed around.
  • the molding material 13 settles and surrounds all surfaces of the model, which is indicated at 28 in FIG. 2.
  • a vibrating device 29 can also be switched on, which sets the molding material in vibrations of a certain amplitude and frequency in order to further compress it, so that the molding material 13 follows the contours of the outer surfaces of the model 28 cleanly and tightly even with complicated shapes.
  • the combination of the formation of a fluidized bed, on the one hand, and a final shaking, on the other hand, ensures that even the most unfavorably lying surface areas are acted upon cleanly by the molding material, on the one hand, by the general upward movement of the molding material in the fluidizing bed and, on the other hand, by the compacting settling movement during shaking.
  • Liquid metal can then be poured onto the plastic of the model 28 in order to gasify it and to fill the mold cavity thus formed with solidified metal melt.
  • the molding material is placed under vacuum by suction, the suction also simultaneously evolving gases.
  • a suction connection 30, separate from the pre-chamber 16, is provided on the molding box 6, from which air and gases are extracted according to arrow 31.
  • the suction connection 30 opens into an annular space 32 designed as a chamber in the lower region of the molding box 6 adjacent to the base plate 15, so that the suction according to arrow 31 results in a flow direction in the molding material 13 which is directed downward from the region of the opening 14.
  • the annular space 32 is separated from the molding space 12 by a gas-permeable partition 33 such that no molding material 13 can penetrate into the annular space 32, but gases can be drawn off from the molding material 13.
  • the gas-permeable partition 33 is preferably designed as a so-called slotted perforated plate, the width of the slits being matched to the grain size of the molding material 13 in such a way that the diameter of the smallest grains of the molding material occurring is on the one hand significantly greater than the width of the slots, but on the other hand significantly below the length of the Slots.
  • the molding material 13 made of sand has a grain size of 0.3 to 0.5, so that a slot width of 0.2 mm is selected with a slot length of 4 mm.
  • Such slotted perforated plates are known for other purposes and are commercially available, so that it is not necessary to go into them in detail.
  • the circumferential wall of the mold space 12, designated as a whole by 34 is formed differently from a cylindrical shape.
  • the circumferential wall 34 has a maximum diameter or maximum width in an equatorial plane 35 and tapers both upwards and downwards from the equatorial plane 35 in the example.
  • a partition wall 36 designed as a circumferential ring.
  • This partition wall 36 like the partition wall 33, consists of a slotted perforated plate and delimits a chamber 37 which is pyramidal in cross section which a suction port 38 is provided.
  • the tapering of the molding box 6 downwards which results in the shape of a truncated cone with a circular cross section of the circumferential wall 34, favors the compression of the molding material 13, in particular under the action of the vibrating device 29, since the bevel of the circumferential wall 34 during the settling movement by the vibrating means an additional movement component of the Molding material in the direction of the vertical center axis of the molding material 12, designated 39.
  • the inclined formation of the circumferential wall 34 from the equatorial plane 35 upwards advantageously prevents any tendency of the molding material to rise, which is to be feared when, in particular, large-volume models are poured and metal of greater density underneath the upper sand layers, which are released by the model fills and thus exerts pressure on the sand.
  • Such a «tendency of the molding material to float effectively counteracts the frustoconical configuration of the peripheral wall 34 above the equatorial plane 35.
  • a cover plate 40 is shown in section in FIG. 3, which is used instead of the film that is usually used in order to favor the application of a vacuum.
  • the molding space 12 should expediently be filled up with molding material 13 up to the mark denoted by 42.
  • a molding box 6 is located in the work station A, the molding space 12 of which is already filled with molding material 13.
  • a model 28, consisting of a gasifiable foam, is now embedded in the molding material 13, while air flows into the mold space 12 from the pre-chamber 16, which is pressurized with compressed air, via the perforated plate 19 through the gas-permeable base plate 15, and slightly swirls the molding material 13.
  • This swirl effect which can be regulated by a control valve (not shown), brings the molding material 13 into a floating state, which allows the model 28 to be introduced into the molding material 13 with practically no resistance.
  • the molding material 13 is compressed by the vibrating device 29 attached to the side of the molding box 6. Then a cover plate 40 is placed on the molding material 13 and the pouring funnel 41 is placed on the model 28 and refilled with additional molding material up to level 42.
  • the rotary table 5 moves one work station further, so that the filled molding box 6 just described moves to work station B.
  • the dwell time serves to cool and solidify the cast molding.
  • the molding is demolded at work station D, this demolding being facilitated by swirling the molding material, as when molding the model 28.
  • the casting thus demolded can then be fed to a work table, also not shown, by means of a lifting magnet, not shown.
  • a separate cooling about a third of the hot molding material 13 is sucked off at the work station D with the aid of the suction device 11, a separate cooling. This extracted amount is symbolically represented in FIG. 2 by means of the double arrow 43.
  • the molding box 6 described in the introduction passes through several dwell times on the workstations E to J, where compressed air is blown in via the antechamber 16 in order to swirl the remaining molding material 13 located in the respective molding space 12, thus cooling the molding material to 40 to 50 ° C.
  • the molding box 6 then arriving from work station J to work station A with a mold space 12 filled only 2/3 of its height then goes through the same work steps as described at the beginning; only with the exception that after the molding of the model 28, the amount of molding material 13 removed at work station D is replenished, with the aid of the filling device 10, which is symbolically indicated in FIG. 2 by the double arrow 44.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Devices For Molds (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)

Abstract

1. An apparatus for carrying out the full-mould casting process having a plurality of moulding boxes (6), in which patterns (28) which can be gasified under the action of poured-in melt are surrounded by granular moulding material (13), which is loosened by compressed air during the moulding of the patterns and during the demoulding of the castings and is hardened under vacuum during the casting process, each mould cavity (12) of the moulding boxes (6) being connected to chambers for the gaseous working media by means of partition walls at least partially limiting said cavity, and in which the moulding boxes (6) can be moved by a circulating, intermittently controlled means of transport to several work-stations forming a closed work system, characterized in that the moulding boxes (6) are connected fixedly to the means of transport (1) and each moulding box has a plurality of mutually independent gaspermeable partition walls (15, 33, 36) with chambers (16, 32, 37) lying therebehind in each case, via which compressed air and vacuum are applied separately to the mould cavity (12) at correspondingly designed work-stations (A to J).

Description

Die Erfindung betrifft eine Einrichtung für die Durchführung des Vollformgießverfahrens mit mehreren Formkasten, in denen unter der Einwirkung eingegossener Schmelze vergasbare Modelle von körnigem Formstoff umgeben sind, der beim Einformen der Modelle und beim Entformen der Gußstücke mit Druckluft aufgelockert und beim Gießprozeß unter Vakuum verfestigt wird, wobei jeder Formraum der Formkasten über diesen zumindest teilweise begrenzende Trennwände mit Kammern für die gasförmigen Arbeitsmedien in Verbindung steht, und bei der die Formkasten mit einem umlaufenden, intermittierend gesteuerten Transportmittel zu mehreren, ein geschlossenes Arbeitssystem bildenden Arbeitsstationen verfahrbar sind.The invention relates to a device for carrying out the full mold casting process with several mold boxes, in which gasified models are surrounded by granular molding material under the influence of poured melt, which is loosened with compressed air when molding the models and when the castings are removed from the mold and solidified under vacuum during the casting process, wherein each molding space of the molding box is connected via these at least partially delimiting partition walls with chambers for the gaseous working media, and in which the molding box can be moved to a plurality of work stations forming a closed work system with a rotating, intermittently controlled means of transport.

Eine derartige Einrichtung ist aus der CH-A-524415 bekannt. Die bei dieser bekannten Einrichtung verwendeten Formkasten haben jeweils eine einteilige Bodenplatte aus porösem Sintermetall, die den mit Formstoff gefüllten Formraum der Formkasten von einer darunterliegenden Vorkammer abteilt, welche an den einzelnen Arbeitsstationen wechselweise mit Druckluft oder mit Vakuum beaufschlagbar ist.Such a device is known from CH-A-524415. The molding boxes used in this known device each have a one-piece base plate made of porous sintered metal, which divides the molding space of the molding box filled with molding material from an underlying prechamber, which can be acted upon alternately with compressed air or with a vacuum at the individual work stations.

Ferner ist aus der DE-B-17 58 521 eine Vorrichtung zur Durchführung des Vollformgießverfahrens bekannt, bei der ein mit einer gasdurchlässigen Bodenplatte versehener Formkasten verwendet wird, bei dem zusätzlich noch die Seitenwände gasdurchlässig ausgebildet sind. Über die hier vorgesehenen gasdurchlässigen Seitenwände soll der überwiegende Teil der beim Gießen entstehenden Verbrennungsgase abgeführt werden, so daß nur geringe Mengen an heißen Gasen über die Bodenplatte in die Vakuumpumpe gelangen können.Furthermore, from DE-B-17 58 521 a device for carrying out the full molding process is known, in which a molding box provided with a gas-permeable base plate is used, in which the side walls are also designed to be gas-permeable. The majority of the combustion gases generated during casting are to be removed via the gas-permeable side walls provided here, so that only small amounts of hot gases can get into the vacuum pump via the base plate.

Es hat sich jedoch gezeigt, daß die bei derartigen Formkasten verwendeten Sintermaterialien aufgrund der durch diese hindurchströmenden Verbrennungsgase relativ leicht zuschmieren, da die Gase auch Dämpfe enthalten, welche in den feinen Hohlräumen des Sintermaterials kondensieren. Letzteres tritt beim Gießen von relativ kleinen Modellen weniger in Erscheinung, da hier die entstehenden Gasmengen auch relativ gering sind. Bei relativ großen Modellen müssen jedoch diese Umstände berücksichtigt werden, da hier die Gasdurchlässigkeit der verwendeten Trennwände durch den Durchtritt einer erhöhten Gasmenge im Laufe der Zeit abnimmt und somit auch die Standzeit der Formkasten.However, it has been found that the sintered materials used in such mold boxes are relatively easy to lubricate due to the combustion gases flowing through them, since the gases also contain vapors which condense in the fine cavities of the sintered material. The latter is less apparent when casting relatively small models, since the amount of gas generated here is also relatively small. With relatively large models, however, these circumstances must be taken into account, since here the gas permeability of the partitions used decreases over time due to the passage of an increased amount of gas, and thus also the service life of the molding boxes.

Bei einer Verwendung von Formkasten mit relativ großen Abmessungen des Formraumes hat sich ferner gezeigt, daß zuweilen keine vollständig zufriedenstellende Ausbildung des sogenannten Fließ- oder Wirbelbettes im Formraum erzielt wird. Ein Grund hierfür dürfte darin liegen, daß die Bodenplatte aus Sintermetall vergleichsweise geringen Strömungswiderstand besitzt, so daß der Strömungswiderstand der insgesamt im Formraum nach oben steigenden Druckluft überwiegend vom Strömungswiderstand des Formstoffes bestimmt wird. Liegt der Formstoff bei Beginn der Druckluftzufuhr in unterschiedlichen Schütthöhen im Formraum vor, so sucht die eingeführte Druckluft den Weg des geringsten Widerstandes, wie z. B. im Bereich einer Senke der Oberfläche des Formstoffes, während Formstoffanhäufungen im Formraum nicht mehr in einer zur Bildung des Wirbelbettes ausreichenden Weise durchströmt werden. Hinzu kommen un- übersichtliche Durchströmungsverhältnisse der Bodenplatte infolge lokal unterschiedlicher Strömungswiderstände insbesondere nach längerer Benutzungsdauer, wenn etwa durch, durch die Bodenplatte hindurch abgesaugte Gase verursacht, Ablagerungen im Sintermaterial der Bodenplatte die Durchströmung behindern.When using molding boxes with relatively large dimensions of the molding space, it has also been shown that sometimes a completely satisfactory formation of the so-called fluidized or fluidized bed is not achieved in the molding space. One reason for this may be that the base plate made of sintered metal has a comparatively low flow resistance, so that the flow resistance of the compressed air which rises overall in the molding space is determined primarily by the flow resistance of the molding material. If the molding material is present at different bed heights in the molding space at the beginning of the compressed air supply, the imported compressed air searches for the path of least resistance, e.g. B. in the region of a depression of the surface of the molding material, while molding material accumulations in the molding space are no longer flowed through in a sufficient manner to form the fluidized bed. In addition, there are confusing flow conditions in the base plate as a result of locally different flow resistances, in particular after a long period of use, if, for example, deposits in the sintered material of the base plate cause gases to flow through them.

Hier setzt die Erfindung ein, der die Aufgabe zugrunde liegt, eine Einrichtung zur Durchführung des Vollformgießverfahrens zu schaffen, mit der es möglich ist, mittelgroße Gußstücke, wie z. B. Zylinderköpfe von wassergekühlten Vierzylinder -Kfz-Motoren oder Gußtrauben, weitgehend automatisiert wirtschaftlich nach dem Vollformgießverfahren herzustellen, wobei gleichzeitig auch bei längerer Betreibsdauer in sicherer Weise eine vollständige Durchwirbelung des Formstoffes bei Einleitung der Druckluft gewährleistet sein muß.This is where the invention comes in, which is based on the object of creating a device for carrying out the full mold casting process, with which it is possible to produce medium-sized castings, such as, for. B. cylinder heads of water-cooled four-cylinder automotive engines or cast grapes, largely automated economically to produce by the full mold casting process, at the same time a complete whirling of the molding material must be guaranteed when the compressed air is introduced even with a long period of operation.

Die Lösung dieser Aufgabe ergibt sich aus den kennzeichnenden Merkmalen des Ansprüchs 1.The solution to this problem results from the characterizing features of claim 1.

Dadurch, daß der Formraum der Formkasten getrennt mit Druckluft und Vakuum an den entsprechenden Arbeitsstationen beaufschlagbar ist, kann jeder Arbeitsschritt an den einzelnen Arbeitsstationen genau definiert werden. Ferner entfällt die Gefahr, daß sich die im Zusammenhang mit der Erzeugung eines Wirbelbettes verwendeten gasdurchlässigen Trennwände nach kurzer Zeit zusetzen ; letzteres bedingt ferner, daß die Intensität der Auflockerung des Formstoffes längerfristig genau steuerbar bleibt und somit eine betriebssichere Automatisierung gewährleistet ist. Hieraus ergibt sich wiederum der Vorteil, daß der Formstoff nach dem Entformen des Gußstückes in dem Formkasten verbleiben kann, da er an mehreren arbeitsstationen durch das erneute Einblasen von Druckluft in einfacher Weise gekühlt werden kann. Die Formkasten müssen daher nach dem Entformen nicht wie üblich vollkommen entleert werden, so daß es genügt, diese ortsfest mit dem Transportmittel zu verbinden, d.h., eine automatische Kippvorrichtung für die Formkasten kann eingespart werden. Ferner ist hervorzuheben, daß bei einer ortsfesten Anordnung der sonst beim Auskippen der Formkasten anfallende Staub hier vorteilhaft nicht anfällt.Because the molding chamber of the molding box can be pressurized separately with compressed air and vacuum at the corresponding work stations, each work step can be precisely defined at the individual work stations. Furthermore, there is no danger that the gas-permeable partition walls used in connection with the production of a fluidized bed will clog after a short time; the latter also means that the intensity of the loosening of the molding material remains precisely controllable in the long term, thus ensuring reliable automation. This in turn has the advantage that the molding material can remain in the molding box after the casting has been removed from the mold, since it can be cooled in a simple manner at several workstations by blowing in compressed air again. The mold boxes therefore do not have to be completely emptied as usual after demolding, so that it is sufficient to connect them stationary to the means of transport, i.e. an automatic tilting device for the mold boxes can be saved. It should also be emphasized that with a stationary arrangement, the dust that otherwise arises when the molding box is dumped is advantageously not produced here.

Bei Formkasten mit größeren Abmessungen des Formraumes kann es im Zusammenhang mit der Kühlung des Formstoffes vorteilhaft sein, daß gemäß einem weiteren Merkmal der Erfindung an der Arbeitsstation Entformen eine Absaugvorrichtung für eine teilweise Entnahme des Formstoffes aus den Formkasten vorgesehen ist. Durch die Verringerung der heißen Formstoffmenge um etwa ein Drittel wird die Durchwirbelung des restlichen Formstoffes erleichtert und somit die Abkühlung beschleunigt. Ferner wird dadurch das Einwirbein größerer Modelle ebenfalls erleichtert, da der Formraum nicht ganz voll ist. Bei einer derartigen Verfahrensweise ist deshalb gemäß einem weiteren Merkmal der Erfindung vorgesehen, daß an der Arbeitsstation Einformen eine Füllvorrichtung für das restliche Füllen der Formkasten mit Formstoff vorgesehen ist. Die beschriebenen Maßnahmen haben den großen Vorteil, daß es im Gegensatz zum Stand der Technik nicht notwendig ist, den gesamten Formstoff separat zu kühlen.In the case of molding boxes with larger dimensions of the molding space, it may be advantageous in connection with the cooling of the molding material that according to a further feature of the invention a suction device is provided for the partial removal of the molding material from the molding box. By reducing the amount of hot molding material by about a third, the swirling of the remaining molding material is facilitated and thus the cooling is accelerated. It also makes it easier to engage larger models, as the mold space is not completely full. In such a procedure, it is therefore provided according to a further feature of the invention that a filling device is provided at the molding work station for the remaining filling of the molding box with molding material. The measures described have the great advantage that, in contrast to the prior art, it is not necessary to cool the entire molding material separately.

Eine weitere wesentliche Verbesserung der erfindungsgemäßen Einrichtung nach dem Oberbegriff des Anspruches 4 erfolgt dadurch, daß unterhalb der Bodenplatte jedes Formkastens eine Lochplatte mit einem gegenüber der Bodenplatte vorzugsweise höheren Strömungswiderstand vorgesehen ist. Durch eine derartige Ausbildung ergibt sich eine Vergleichmäßigung des lokalen Vorlagedrucks der Druckluft in der Vorkammer an der Oberfläche der Lochplatte, so daß jedes Loch der Lochplatte im wesentlichen dasselbe Druckluftangebot erhält. Die Druckluft tritt dann an den den Löchern entsprechenden diskreten Stellen durch die Lochplatte hindurch in einer quer zur Ebene der Lochplatte liegenden Kernströmung und strömt so die Unterseite der Bodenplatte mit relativ geringem Strömungswiderstand in einer Vielzahl von einzelnen düsenartigen Strahlen an. Infolge des vergleichsweise geringeren Strömungswiderstandes der Bodenplatte ergibt sich oberhalb der Bodenplatte ein gleichmäßiger Austritt der Druckluft, so daß dadurch keine Geschwindigkeitsspitzen auftreten, d.h. wo die Druckluft mit vergleichsweise hoher Energie tief in den Formstoff eindringt und ein sogenanntes schädliches « Blubbern » hervorruft, was bei der Verwendung einer reinen Lochplatte der Fall wäre. Damit werden übersichtliche, für die Ausbildung des Wirbelbettes günstige Strömungsverhältnisse über der gesamten Fläche über der Bodenplatte geschaffen und somit zuverlässig ein voll ausgebildetes Wirbelbett erzielt, selbst wenn zu Beginn der Druckluftzufuhr der Formstoff in erheblich unterschiedlichen Schütthöhen im Formraum vorliegen sollte.A further significant improvement of the device according to the preamble of claim 4 takes place in that a perforated plate with a flow resistance which is preferably higher than the base plate is provided below the bottom plate of each molding box. Such a design results in an equalization of the local supply pressure of the compressed air in the prechamber on the surface of the perforated plate, so that each hole of the perforated plate receives essentially the same supply of compressed air. The compressed air then passes at the discrete points corresponding to the holes through the perforated plate in a core flow lying transversely to the plane of the perforated plate and thus flows onto the underside of the base plate with a relatively low flow resistance in a large number of individual nozzle-like jets. As a result of the comparatively lower flow resistance of the base plate, there is a uniform outlet of the compressed air above the base plate, so that no speed peaks occur, i.e. where the compressed air penetrates deep into the molding material with comparatively high energy and causes a so-called harmful “bubbling”, which would be the case if a pure perforated plate were used. This creates clear, favorable flow conditions for the formation of the fluidized bed over the entire area above the base plate and thus reliably achieves a fully developed fluidized bed, even if the molding material should be present in the molding space at significantly different bed heights at the start of the compressed air supply.

Weitere Einzelheiten, Merkmale und Vorteile der Erfindung ergeben sich aus der nachfolgenden Beschreibung einer Ausführungsform anhand einer Zeichnung.Further details, features and advantages of the invention result from the following description of an embodiment with reference to a drawing.

Es zeigt

  • Fig. 1 eine Draufsicht auf eine vereinfachte Darstellung einer erfindungsgemäßen Einrichtung zur Durchführung des Vollformgießverfahrens,
  • Fig. 2 einen Schnitt nach Linie 11/11 gemäß Fig. 1,
  • Fig. 3 in schematisch vereinfachter Darstellung einen Vertikalschnitt durch einen erfindungsgemäßen Formkasten und
  • Fig. 4 die Einzelheit aus Kreis IV in Fig. 3 in vergrößerter Darstellung.
It shows
  • 1 is a plan view of a simplified representation of a device according to the invention for carrying out the full molding process,
  • 2 shows a section along line 11/11 of FIG. 1,
  • Fig. 3 shows a schematic simplified representation of a vertical section through a molding box according to the invention and
  • Fig. 4 shows the detail from circle IV in Fig. 3 in an enlarged view.

Wie aus Fig. 1 und 2 ersichtlich ist, besteht die Einrichtung für die Durchführung des Vollformgießverfahrens im wesentlichen aus einer als Transportmittel 1 dienende Rundlaufanlage, die im Sinne der Arbeitsschritte ein geschlossenes System bildet. Sie besitzt einem auf einer Grundplatte 2 ruhenden Ständer 3, auf welchen mit einem Lagerring 4 ein Drehtisch 5 drehbar gelagert ist. Auf dem Drehtisch 5 sind bei dem vorliegenden Beispiel neun Formkasten im gleichen Abstand ortsfest, d. h. nicht kippbar befestigt.As can be seen from FIGS. 1 and 2, the device for carrying out the full molding process essentially consists of a rotary system serving as a means of transport 1, which forms a closed system in the sense of the work steps. It has a stand 3 resting on a base plate 2, on which a turntable 5 is rotatably mounted with a bearing ring 4. In the present example, nine molding boxes are stationary on the turntable 5 at the same distance, i. H. not fixed tiltable.

Wie ferner aus Fig. 2 zu entnehmen ist, kämmt eine Antriebswelle 7 eines Elektromotors 8 mit einem drehfesten Zahnkranz 9 des Drehtisches 5. Routierend angetrieben durch den Elektromotor 8 ist dabei die Drehbewegung des Drehtisches 5 durch nicht dargestellte Steuermittel derart intermittierend gesteuert, daß jeweils ein Formkasten 6 an den in Fig. 1 mit A bis J bezeichneten Arbeitsstationen zeitlich abgestimmte Halte macht.As can also be seen from Fig. 2, a drive shaft 7 of an electric motor 8 meshes with a non-rotatable ring gear 9 of the turntable 5. Routed by the electric motor 8, the rotary movement of the turntable 5 is controlled intermittently by control means, not shown, in such a way that one Molding box 6 at the work stations labeled A to J in FIG. 1 makes timed stops.

An der Arbeisstation A erfolgen die Arbeitsschritte Einformen, d. h. Erzeugen eines Wirbelbettes, dann Füllen des restlichen Formstoffes in den Formkasten und schließlich Gießen. Das Füllen erfolgt mit Hilfe einer nicht näher dargestellten Füllvorrichtung, die durch den Pfeil 10 symbolisiert ist. Bei den Arbeitsstationen B und C erfolgen die Arbeitsschritte Erstarren, deren Anzahl jedoch erweitert werden kann. Ferner wird bei D der Arbeitsschritt Entformen, d. h. Aufwirbelung des Formstoffes und Entnehmen des Gußstückes, durchgeführt, wobei hier zusätzlich der Arbeitsschritt teilweise Entnahme des Formstoffes aus dem Formkasten erfolgt. Hierzu dient eine mit dem Pfeil 11 symbolisierte Absaugvorrichtung 11, die in bekannter Weise nach dem Prinzip eines Staubsaugers arbeiten kann. Schließlich folgen die Arbeitsstationen E bis J (oder weitere), bei denen der Formstoff mittels des Anlegens eines Wirbelbettes auf 40 °C bis 50 °C abgekühlt wird. Jeder Formkasten 6 hat einen kreisförmigen Querschnitt und einen inneren Formraum 12 zur Aufnahme des körnigen Formstoffes 13, der im vorliegenden Fall aus bindemittelfreiem Sand besteht. Der Formstoff 13 wird durch eine obere Öffnung 14 in den Formraum 12 eingefüllt und liegt an der Unterseite des Formraumes 12 auf einer eine Trennwand bildende Bodenplatte 15 auf.At work station A, the molding steps are carried out, i. H. Create a fluidized bed, then fill the remaining molding material into the molding box and finally pour. The filling takes place with the aid of a filling device, not shown, which is symbolized by the arrow 10. At workstations B and C, the work steps solidify, but the number can be expanded. At D the step of demolding, i.e. H. Whirling up the molding material and removing the casting, carried out, in which case the step of partially removing the molding material from the molding box also takes place here. For this purpose, a suction device 11 symbolized by the arrow 11 is used, which can work in a known manner on the principle of a vacuum cleaner. Finally, work stations E to J (or others) follow, in which the molding material is cooled to 40 ° C. to 50 ° C. by creating a fluidized bed. Each molding box 6 has a circular cross section and an inner molding space 12 for receiving the granular molding material 13, which in the present case consists of binder-free sand. The molding material 13 is filled into the molding space 12 through an upper opening 14 and rests on the underside of the molding space 12 on a base plate 15 which forms a partition.

Unterhalb des Formraumes 12 bzw. der Bodenplatte 15 ist eine Vorkammer 16 mit einem Anschluß 17 für die Zuführung von Druckluft gemäß Pfeil 18 vorgesehen. Die in die Vorkammer 16 einströmende Druckluft steht an der Unterseite der Bodenplatte 15 an. Die Bodenplatte 15 ist gasdurchlässig ausgebildet, so daß die anstehende Druckluft durch die Bodenplatte 15 hindurch in den Formraum 12 eindringen und den dortigen Formstoff 13 verwirbeln kann, so daß ein Fließ-oder Wirbelbett entsteht.A pre-chamber 16 with a connection 17 for the supply of compressed air according to arrow 18 is provided below the molding space 12 or the base plate 15. The compressed air flowing into the pre-chamber 16 is present on the underside of the base plate 15. The base plate 15 is designed to be gas-permeable, so that the compressed air present penetrates through the base plate 15 into the mold space 12 and the mold space 12 there Swirl molding material 13, so that a fluidized or fluidized bed is formed.

Es hat sich gezeigt, daß die Druckluft durch die beispielsweise aus Sintermetall bestehende Bodenplatte 15, wenn diese die alleinige Trennung zwischen dem Formraum 12 und der Vorkammer 16 bildet, in stark unterschiedlicher lokaler Strömung hindurchtriff. Derartige Unterschiede in der Durchströmung der Bodenplatte 15 können aus lokal unterschiedlichen Strömungswiderständen des Sintermaterials resultieren, sowie insbesondere aus lokal unterschiedlichen Schütthöhen des Formstoffes 13 im Formraum 12. Anhäufungen des Formstoffes 12 im Formraum 12 werden dabei infolge des höheren Strömungswiderstandes von der Druckluft lediglich in einer zur Fluidisierung nicht mehr ausreichenden Intensität durchströmt, so daß die volle Ausbildung des Wirbelbettes behindert ist.It has been shown that the compressed air passes through the base plate 15, which is made of sintered metal, for example, when it forms the sole separation between the molding space 12 and the pre-chamber 16, in a very different local flow. Such differences in the flow through the base plate 15 can result from locally different flow resistances of the sintered material, and in particular from locally different pouring heights of the molding material 13 in the molding space 12. Accumulations of the molding material 12 in the molding space 12 become due to the higher flow resistance of the compressed air only in one Fluidization no longer flows through sufficient intensity, so that the full formation of the fluidized bed is hindered.

Zur Erzeugung eines homogenen voll ausgebildeten Wirbelbettes ist deshalb unterhalb der Bodenplatte 15 eine Lochplatte 19 beispielsweise aus metall angeordnet, die für den Luftdurchtritt Löcher 20 aufweist. Der Strömungswiderstand der Lochplatte 19 mit den Löchern 20 ist insgesamt relativ hoch ; jedenfalls höher als derjenige Strömungswiderstand, der bei der beispielsweise aus Sintermaterial bestehenden Bodenplatte 15 vorliegt. Damit bildet die Lochplatte 19 den hauptsächlichen Strömungswiderstand für die Druckluft in der Vorkammer 16 und bildet gewissermaßen eine Drossel, vor der sich ein über die Fläche der Lochplatte 19 gleichmäßiger, relativ hoher Vorlagedruck aufbaut, der eine Höhe von beispielsweise bis 0,5 MPa (5 bar) besitzen kann. Der Vorlagedruck an der Unterseite der Lochplatte 19 drückt die Druckluft in diskreten Strömungen durch die Löcher 20 hindurch, die somit ähnlich Düsen wirken, so daß die Unterseite der Bodenplatte 15 in der Fig. 4 angedeuteten Weise gemäß Pfeilen 21 angeströmt wird. Würde nun die Bodenplatte 15 fehlen und die Kernströmung gemäß Pfeilen 21 unmittelbar in den Formstoff 13 eintreten, so ergäbe sich ein Geschwindigkeitsprofil der einströmenden Druckluft, wie dies in Fig. 4 mit einer strichpunktierten Linie 22 und entsprechenden Geschwindigkeitspfeilen 23 beispielhaft veranschaulicht ist. Auf diese Weise würde im Bereich jedes Loches 20 eine Kernströmung gemäß den Pfeilen 21 sowie Geschwindigkeitsprofil 22 erzielt, die annähernd lanzenartig in den Formstoff 13 hineinsticht und tief in diesen eindringt, so daß durch das Geschwindigkeitsprofil 22 eine zu intensive Durchwirbelung und somit Staubentwicklung des Formstoffes 13 entsteht, die vermieden werden muß.To produce a homogeneous fully formed fluidized bed, a perforated plate 19, for example made of metal, is therefore arranged below the base plate 15 and has holes 20 for the passage of air. The flow resistance of the perforated plate 19 with the holes 20 is relatively high overall; in any case higher than the flow resistance that is present in the base plate 15, which is made of sintered material, for example. The perforated plate 19 thus forms the main flow resistance for the compressed air in the pre-chamber 16 and forms, so to speak, a throttle in front of which a relatively high supply pressure builds up over the surface of the perforated plate 19, which has a height of, for example, up to 0.5 MPa (5 bar) can have. The supply pressure on the underside of the perforated plate 19 presses the compressed air through the holes 20 in discrete flows, which thus act in a similar manner to nozzles, so that the underside of the bottom plate 15 is flowed towards in the manner indicated by arrows 21 in FIG. 4. If the base plate 15 were now missing and the core flow directly into the molding material 13 according to arrows 21, this would result in a speed profile of the inflowing compressed air, as is illustrated in FIG. 4 by a dash-dotted line 22 and corresponding speed arrows 23. In this way, a core flow according to the arrows 21 and the speed profile 22 would be achieved in the area of each hole 20, which penetrates into the molding material 13 in an approximately lance-like manner and penetrates deeply into it, so that the speed profile 22 causes excessive swirling and thus dust formation of the molding material 13 arises, which must be avoided.

Durch die Kombination Bodenplatte 15/Lochplatte 19 wird dieser Nachteil des sogenannten « Blubberns » beseitigt, und man erhält vorteilhaft ein gleichmäßiges Geschwindigkeitsprofil der in den Formstoff 13 einströmenden Druckluft, wie ebenfalls in Fig. 4 mit der gestrichelten Linie 24 und entsprechenden Geschwindigkeitspfeilen 25 gezeigt ist. Die in diesem Zusammenhang vorgesehenen Löcher 20 haben einen Durchmesser zwischen etwa 2 und 6 mm, vorzugsweise zwischen 3 und 5 mm und im veranschaulichten Beispielsfalle von 4 mm. Sie liegen in einem gegenseitigen Abstand von mehreren cm, bevorzugt zwischen 3 und 5 cm, im Beispielsfalle in einem Abstand von 4 cm.The combination of base plate 15 / perforated plate 19 eliminates this disadvantage of so-called “bubbling”, and advantageously a uniform speed profile of the compressed air flowing into the molding material 13 is obtained, as is also shown in FIG. 4 with the dashed line 24 and corresponding speed arrows 25 . The holes 20 provided in this connection have a diameter between approximately 2 and 6 mm, preferably between 3 and 5 mm and in the illustrated example case of 4 mm. They are at a mutual distance of several cm, preferably between 3 and 5 cm, in the example at a distance of 4 cm.

Auf der vergleichsweise dünnen Lochplatte 19 liegt der erhebliche Vorlagedruck in der Vorkammer 16, so daß zur rückseitigen Abstützung der Lochplatte 19 Abstandshalter 26 vorgesehen sind, die im Beispielsfalle gitterartig angeordnet sind und so eine flächig wirkende rückseitige Abstützung für die Lochplatte 19 bilden. Die gitterartig angeordneten Abstandshalter 26 begrenzen jeweils quadratische Kammern 27, wobei jeweils ein Loch 20 der Lochplatte 19 einer Kammer 27 mittig zugeordnet ist. Dadurch, daß die Abstandshalter 26 die nebeneinanderliegenden Kammern 27 weitgehend gegeneinander abdichten, ist insbesondere sichergestellt, daß die Druckluft pro Kammer 27 gleichmäßig durch die Bodenplatte 15 austritt, so daß das gleichmäßige Strömungsprofil 24 erhalten wird.On the comparatively thin perforated plate 19, the considerable supply pressure lies in the antechamber 16, so that spacers 26 are provided for the rear support of the perforated plate 19, which are arranged in a grid-like manner in the example and thus form a flat-looking rear support for the perforated plate 19. The spacers 26 arranged in a grid-like manner each delimit square chambers 27, a hole 20 of the perforated plate 19 being assigned to a chamber 27 in the center. The fact that the spacers 26 largely seal the adjacent chambers 27 against one another ensures in particular that the compressed air per chamber 27 exits evenly through the base plate 15, so that the uniform flow profile 24 is obtained.

Der Arbeitsablauf der weitgehend automatisch arbeitenden Vollformgießanlage gemäß Fig. 1 und 2 ist der folgende, wobei vorerst die Arbeitsweise eines Formkastens 6 und dessen besonderen weiteren Ausführungsformen vom Prinzip her beschrieben wird.1 and 2 is the following, the mode of operation of a molding box 6 and its particular further embodiments being described in principle for the time being.

Im Betrieb wird der in dem Formraum 12 befindliche Formstoff 13 durch Druckluftzufuhr gemäß Pfeil 18 in der geschilderten Weise fluidisiert. In diesem Zustand verhält sich der Formstoff 13 im wesentlichen wie eine Flüssigkeit, so daß ein Modell aus expandiertem Polystyrol, wie dies beim Vollformgießen üblich ist, durch die Öffnung 14 hindurch leicht und beschädigungsfrei in den fluidisierten Formstoff 13 eingeführt werden kann und von diesem auch bei komplizierten Hinterschneidungen oder dergleichen vollständig umspült wird. Nach Unterbrechung der Druckluftzufuhr gemäß Pfeil 18 setzt sich der Formstoff 13 ab und umgibt sämtliche Oberflächen des Modells, welches in Fig. 2 bei 28 angedeutet ist. Während der Drosselung der Druckluftzufuhr kann zugleich eine Rütteleinrichtung 29 zugeschaltet werden, die den Formstoff in Vibrationen bestimmter Amplitude und Frequenz versetzt, um ihn weiter zu verdichten, damit der Formstoff 13 den Konturen der Außenoberflächen des Modells 28 auch bei komplizierten Formen sauber und dicht folgt. Die Kombination der Bildung eines Wirbelbettes einerseits und eines abschließenden Rüttelns andererseits gewährleistet, daß auch ungünstigst liegende Oberflächenbereiche einerseits durch die generelle Aufwärtsbewegung des Formstoffes im Wirbelbett und andererseits durch die verdichtende Absetzbewegung bei der Rüttelung sauber vom Formstoff beaufschlagt werden.In operation, the molding material 13 located in the molding space 12 is fluidized in the manner described by compressed air supply according to arrow 18. In this state, the molding material 13 behaves essentially like a liquid, so that a model made of expanded polystyrene, as is customary in full mold casting, can be introduced through the opening 14 easily and without damage into and from the fluidized molding material 13 complicated undercuts or the like is completely washed around. After interrupting the compressed air supply according to arrow 18, the molding material 13 settles and surrounds all surfaces of the model, which is indicated at 28 in FIG. 2. During the throttling of the compressed air supply, a vibrating device 29 can also be switched on, which sets the molding material in vibrations of a certain amplitude and frequency in order to further compress it, so that the molding material 13 follows the contours of the outer surfaces of the model 28 cleanly and tightly even with complicated shapes. The combination of the formation of a fluidized bed, on the one hand, and a final shaking, on the other hand, ensures that even the most unfavorably lying surface areas are acted upon cleanly by the molding material, on the one hand, by the general upward movement of the molding material in the fluidizing bed and, on the other hand, by the compacting settling movement during shaking.

Sodann kann flüssiges Metall auf den Kunststoff des Modells 28 gegossen werden, um diesen zu vergasen und den so gebildeten Formhohlraum mit verfestigter Metallschmelze anzufüllen. Um hier eine weitere Verbesserung der Stabilität der Wände des Formstoffes 13 entlang der Kontur des Modells 28 zu erhalten, wird der Formstoff von unten her durch Absaugung unter Unterdruck gesetzt, wobei die Absaugung zugleich auch entstehende Gase mit abführt. Hierzu ist am Formkasten 6 ein gegenüber der Vorkammer 16 getrennter Absauganschluß 30 vorgesehen, aus dem Luft und Gase gemäß Pfeil 31 abgesaugt werden. Der Absauganschluß 30 mündet in einen als Kammer ausgebildeten Ringraum 32 im unteren, der Bodenplatte 15 benachbarten Bereich des Formkastens 6, so daß die Absaugung gemäß Pfeil 31 eine Strömungsrichtung im Formstoff 13 ergibt, die vom Bereich der Öffnung 14 nach unten gerichtet ist. Der Ringraum 32 ist über eine gasdurchlässige Trennwand 33 gegenüber dem Formraum 12 derart abgetrennt, daß kein Formstoff 13 in den Ringraum 32 eindringen kann, jedoch Gase aus dem Formstoff 13 abgezogen werden können.Liquid metal can then be poured onto the plastic of the model 28 in order to gasify it and to fill the mold cavity thus formed with solidified metal melt. To further improve the stability of the walls of the molding material 13 along the contour to obtain the model 28, the molding material is placed under vacuum by suction, the suction also simultaneously evolving gases. For this purpose, a suction connection 30, separate from the pre-chamber 16, is provided on the molding box 6, from which air and gases are extracted according to arrow 31. The suction connection 30 opens into an annular space 32 designed as a chamber in the lower region of the molding box 6 adjacent to the base plate 15, so that the suction according to arrow 31 results in a flow direction in the molding material 13 which is directed downward from the region of the opening 14. The annular space 32 is separated from the molding space 12 by a gas-permeable partition 33 such that no molding material 13 can penetrate into the annular space 32, but gases can be drawn off from the molding material 13.

Bevorzugt ist die gasdurchlässige Trennwand 33 als sogenanntes Schlitzlochblech ausgebildet, wobei die Breite der Schlitze auf die Korngröße des Formstoffes 13 derart abgestimmt wird, daß der Durchmesser der kleinsten auftretenden Körner des Formstoffes einerseits deutlich über der Breite der Schlitze, andererseits aber deutlich unterhalb der Länge der Schlitze liegt. Im vorliegenden Fall hat der Formstoff 13 aus Sand eine Korngröße von 0,3 bis 0,5, so daß eine Schlitzbreite von 0,2 mm bei einer Schlitzlänge von 4 mm gewählt ist. Derartige Schlitzlochbleche sind zu anderen Zwechen bekannt und im Handel, so daß ein näheres Eingehen hierauf entbehrlich ist.The gas-permeable partition 33 is preferably designed as a so-called slotted perforated plate, the width of the slits being matched to the grain size of the molding material 13 in such a way that the diameter of the smallest grains of the molding material occurring is on the one hand significantly greater than the width of the slots, but on the other hand significantly below the length of the Slots. In the present case, the molding material 13 made of sand has a grain size of 0.3 to 0.5, so that a slot width of 0.2 mm is selected with a slot length of 4 mm. Such slotted perforated plates are known for other purposes and are commercially available, so that it is not necessary to go into them in detail.

Dadurch, daß die Absaugung der durch die Schmelze gebildeten heißen Gase durch die der Bodenplatte 15 benachbarten Trennwand 33 hindurch erfolgt, ist vermieden, daß diese Gase die aus Sintermetall bestehende Bodenplatte 15 durchsetzen muß. Durch diesen Umstand wird eine allmähliche Veränderung des Strömungswiderstandes der Bodenplatte 15 durch Ablagerungen aus dem Gasstrom verhindert, so daß diese über längeren Betrieb hinweg unveränderte Strömungseigenschaften beibehält. Ferner ist es durch den zweiteiligen Aufbau Bodenplatte 15/Lochplatte 19 einerseits und durch die getrennte Absaugung der heißen Gase andererseits möglich, für die Bodenplatte 15 auch ein Sinterkunststoff zu verwenden, was gegenüber Sintermetall funktionelle Vorteile und Kostenvorteile mit sich bringt.Characterized in that the suction of the hot gases formed by the melt takes place through the partition wall 33 adjacent to the base plate 15, it is avoided that these gases have to pass through the base plate 15 made of sintered metal. This fact prevents a gradual change in the flow resistance of the base plate 15 due to deposits from the gas stream, so that it maintains unchanged flow properties over a long period of operation. Furthermore, the two-part construction of the base plate 15 / perforated plate 19 on the one hand and the separate extraction of the hot gases on the other hand also make it possible to use a sintered plastic for the base plate 15, which has functional advantages and cost advantages over sintered metal.

Wie aus Fig. 3 ferner ersichtlich ist, ist die insgesamt mit 34 bezeichnete Umfangswand des Formraumes 12 abweichend von einer Zylinderform ausgebildet. In einem mittleren Höhenbereich des Formkastens 6 weist die Umfangswand 34 in einer Äquatorebene 35 maximalen Durchmesser bzw. maximale Weite auf und verjüngt sich im Beispielsfalle von der Äquatorebene 35 aus sowohl nach oben als auch nach unten. In dem Bereich der Äquatorebene 35 ist im vorliegenden Fall eine weitere Möglichkeit zum Absaugen der Verbrennungsgase vorgesehen, und zwar eine als Umfangsring ausgebildete Trennwand 36. Diese Trennwand 36 besteht ebenfalls wie die Trennwand 33 aus einem Schlitzlochblech und begrenzt eine im Querschnitt pyramidenförmige Kammer 37, an welcher ein Absauganschluß 38 vorgesehen ist.As can also be seen from FIG. 3, the circumferential wall of the mold space 12, designated as a whole by 34, is formed differently from a cylindrical shape. In a central height range of the molding box 6, the circumferential wall 34 has a maximum diameter or maximum width in an equatorial plane 35 and tapers both upwards and downwards from the equatorial plane 35 in the example. In the area of the equatorial plane 35, in the present case there is a further possibility for extracting the combustion gases, namely a partition wall 36 designed as a circumferential ring. This partition wall 36, like the partition wall 33, consists of a slotted perforated plate and delimits a chamber 37 which is pyramidal in cross section which a suction port 38 is provided.

Die Verjüngung des Formkastens 6 nach unten, die bei kreisförmigem Querschnitt der Umfangswand 34 umgekehrte Kegelstumpfform ergibt, begünstigt die Verdichtung des Formstoffes 13, insbesondere unter der Einwirkung der Rütteleinrichtung 29, da die Schräge der Umfangswand 34 bei der Absetzbewegung durch die Rüttelung eine zusätzliche Bewegungskomponente des Formstoffes in Richtung auf die mit 39 bezeichnete vertikale Mittelachse des Formstoffes 12 ergibt. Die schräge Ausbildung der Umfangswand 34 von der Äquatorebene 35 aus nach oben behindert in vorteilhafter Weise jegliche Tendenz des Formstoffes zu einem Aufsteigen, die dann zu befürchten ist, wenn insbesondere großvolumige Modelle abgegossen werden und Metall größerer Dichte die vom Modell freigegebenen Hohlräume unterhalb der oberen Sandschichten füllt und damit Auftriebsdruck auf den Sand ausübt. Ein solchen « Aufschwimmtendenz des Formstoffes wirkt die oberhalb der Äquatorebene 35 kegelstumpfförmige Ausbildung der Umfangswand 34 wirksam entgegen.The tapering of the molding box 6 downwards, which results in the shape of a truncated cone with a circular cross section of the circumferential wall 34, favors the compression of the molding material 13, in particular under the action of the vibrating device 29, since the bevel of the circumferential wall 34 during the settling movement by the vibrating means an additional movement component of the Molding material in the direction of the vertical center axis of the molding material 12, designated 39. The inclined formation of the circumferential wall 34 from the equatorial plane 35 upwards advantageously prevents any tendency of the molding material to rise, which is to be feared when, in particular, large-volume models are poured and metal of greater density underneath the upper sand layers, which are released by the model fills and thus exerts pressure on the sand. Such a «tendency of the molding material to float effectively counteracts the frustoconical configuration of the peripheral wall 34 above the equatorial plane 35.

Schließlich ist in Fig. 3 noch ein Abdeckblech 40 im Schnitt gezeigt, das anstelle der üblicherweise verwendeten Folie eingesetzt wird, um das Anlegen eines Vakuums zu begünstigen. Nach dem Einbringen des Abdeckbleches 40 und eines Gießtrichters 41 soll der Formraum 12 zweckmäßigerweise bis zu der mit 42 bezeichneten Marke wieder mit Formstoff 13 aufgefüllt werden.Finally, a cover plate 40 is shown in section in FIG. 3, which is used instead of the film that is usually used in order to favor the application of a vacuum. After the introduction of the cover plate 40 and a pouring funnel 41, the molding space 12 should expediently be filled up with molding material 13 up to the mark denoted by 42.

Zu Beginn des Betriebes der erfindungsgemäßen Einrichtung für das Vollformgießverfahren gemäß Fig. 1 und 2 steht in der Arbeitsstation A ein Formkasten 6, dessen Formraum 12 bereits mit Formstoff 13 gefüllt ist. Ein Modell 28, bestehend aus einem vergasbaren Schaumstoff, wird nun in den Formstoff 13 eingebettet, während von der mit Druckluft beaufschlagten Vorkammer 16 über die Lochplatte 19 durch die gasdurchlässige Bodenplatte 15 Luft in den Formraum 12 einströmt und den Formstoff 13 in leichte Verwirbelung versetzt. Dieser durch ein nichtgezeigtes Regelventil regelbare Wirbeleffekt bringt den Formstoff 13 in einen schwimmenden Zustand, welcher eine praktisch widerstandslose Einführung des Modells 28 in den Formstoff 13 erlaubt. Kurz vor dem Abschalten der Druckluft wird der Formstoff 13 durch die seitlich an dem Formkasten 6 angebrachten Rüttelvorrichtung 29 verdichtet. Anschließend wird auf den Formstoff 13 ein Abdeckblech 40 gelegt und der Eingußtrichter 41 auf das Modell 28 aufgesetzt und bis zum Niveau 42 weiterer Formstoff nachgefüllt.At the beginning of the operation of the device according to the invention for the full molding process according to FIGS. 1 and 2, a molding box 6 is located in the work station A, the molding space 12 of which is already filled with molding material 13. A model 28, consisting of a gasifiable foam, is now embedded in the molding material 13, while air flows into the mold space 12 from the pre-chamber 16, which is pressurized with compressed air, via the perforated plate 19 through the gas-permeable base plate 15, and slightly swirls the molding material 13. This swirl effect, which can be regulated by a control valve (not shown), brings the molding material 13 into a floating state, which allows the model 28 to be introduced into the molding material 13 with practically no resistance. Shortly before the compressed air is switched off, the molding material 13 is compressed by the vibrating device 29 attached to the side of the molding box 6. Then a cover plate 40 is placed on the molding material 13 and the pouring funnel 41 is placed on the model 28 and refilled with additional molding material up to level 42.

Danach werden die Ringräume 32 und 37 des Formkastens 6 unter Vakuum gesetzt, wodurch eine Steigerung der Festigkeit des Formstoffes 13 und eine Fixation derselben während des nun erfolgenden Gießprozesses erreicht wird. Der Gießprozeß vollzieht sich dabei unter Verbrennung und Vergasung des aus Schaumstoff bestehenden Modells 28.Thereafter, the annular spaces 32 and 37 of the molding box 6 are placed under vacuum, as a result of which the strength of the molding material 13 is increased and the same is fixed during the casting process now taking place. The casting process takes place with combustion and gasification of the best of foam model 28.

Nach Beendigung des Gießvorganges rückt der Rundtisch 5 um eine Arbeitsstation weiter, so daß der eben beschriebene gefüllte Formkasten 6 zur Arbeitsstation B wandert. Hier und auch bei der nächstfolgenden Arbeitsstation C dient die Verweilzeit der Abkühlung und Erstarrung des gegossenen Formlings.After completion of the casting process, the rotary table 5 moves one work station further, so that the filled molding box 6 just described moves to work station B. Here and also at the next work station C, the dwell time serves to cool and solidify the cast molding.

Auf der Arbeitsstation D wird der Formling entformt, wobei diese Entformung, wie beim Einformen des Modells 28, unter Verwirbelung des Formstoffes erleichtert wird. Das so entformte Gußstück kann dann mittels eines nicht dargestellten Hubmagnetes einem ebenfalls nicht dargestellten Arbeitstisch zugeführt werden. Gleichzeitig wird an der Arbeitsstation D mit Hilfe der Absaugvorrichtung 11 etwa ein Drittel des heißen Formstoffes 13 eine separate Kühlung abgesaugt. Diese abgesaugte Menge ist in Fig. 2 mittels des Doppelpfeiles 43 symbolisch dargestellt.The molding is demolded at work station D, this demolding being facilitated by swirling the molding material, as when molding the model 28. The casting thus demolded can then be fed to a work table, also not shown, by means of a lifting magnet, not shown. At the same time, about a third of the hot molding material 13 is sucked off at the work station D with the aid of the suction device 11, a separate cooling. This extracted amount is symbolically represented in FIG. 2 by means of the double arrow 43.

Danach durchläuft der eingangs beschriebene Formkasten 6 mehrere Verweilzeiten auf den Arbeitsstationen E bis J, wo jeweils über die Vorkammer 16 Druckluft zur Verwirbelung des restlichen im jeweiligen formraum 12 befindlichen Formstoffes 13 eingeblasen wird und somit den Formstoff auf 40 bis 50°C abkühlt.Thereafter, the molding box 6 described in the introduction passes through several dwell times on the workstations E to J, where compressed air is blown in via the antechamber 16 in order to swirl the remaining molding material 13 located in the respective molding space 12, thus cooling the molding material to 40 to 50 ° C.

Der von der Arbeitsstation J dann zur Arbeitsstation A gelangende Formkasten 6 mit einer nur 2/3 seiner Höhe gefüllten Formraum 12 durchläuft dann dieselben Arbeitsschritte wie eingangs beschrieben ; lediglich mit der Ausnahme, daß nach dem Einformen des Modells 28 die bei Arbeitsstation D entnommene Menge an Formstoff 13 wieder nachgefüllt wird, und zwar mit Hilfe der Füllvorrichtung 10, was in Fig. 2 symbolisch mit dem Doppelpfeil 44 angedeutet ist.The molding box 6 then arriving from work station J to work station A with a mold space 12 filled only 2/3 of its height then goes through the same work steps as described at the beginning; only with the exception that after the molding of the model 28, the amount of molding material 13 removed at work station D is replenished, with the aid of the filling device 10, which is symbolically indicated in FIG. 2 by the double arrow 44.

Claims (12)

1. An apparatus for carrying out the full-mould casting process having a plurality of moulding boxes (6), in which patterns (28) which can be gasified under the action of poured-in melt are surrounded by granular moulding material (13), which is loosened by compressed air during the moulding of the patterns and during the demoulding of the castings and is hardened under vacuum during the casting process, each mould cavity (12) of the moulding boxes (6) being connected to chambers for the gaseous working media by means of partition walls at least partially limiting said cavity, and in which the moulding boxes (6) can be moved by a circulating, intermittently controlled means of transport to several workstations forming a closed work system, characterized in that the moulding boxes (6) are connected fixedly to the means of transport (1) and each moulding box has a plurality of mutually independent gaspermeable partition walls (15, 33, 36) with chambers (16, 32, 37) lying therebehind in each case, via which compressed air and vacuum are applied separately to the mould cavity (12) at correspondingly designed workstations (A to J).
2. An apparatus according to claim 1, characterized in that a filling device (10) for the remaining filling (44) of the moulding boxes (6) is provided at the moulding workstation (A).
3. An apparatus according to claim 1 or 2, characterized in that an evacuation device (11) for partial removal (43) of the moulding material (13) from the moulding boxes (6) is provided at the demoulding workstation (D).
4. An apparatus according to any of claims 1 to 3, having moulding boxes whose base plate is designed as a gas-permeable partition wall which on one side limits a prechamber which is provided with a connection for the supply of compressed air, characterized in that a perforated plate (19) having a preferably higher flow resistance than the base plate (15) is provided underneath the base plate (15).
5. An apparatus according to claim 4, characterized in that spacers (26) are arranged between the perforated plate (19) and the base plate (15), which spacers are designed as webs bounding chambers (27).
6. An apparatus according to claim 5, characterized in that each chamber (27) has an associated hole (20) in at least approximately central arrangement with respect to the chamber (27).
7. An apparatus according to any of claims 1 to 6, characterized in that an evacuation connection (30) for negative pressure generation in the moulding material (13) si provided at each moulding box (6), and in that the peripheral wall (34) limiting the moulding material (13) is designed in the lower region of the moulding box (6) adjacent to the base plate (15) as a gas-permeable partition wall (33) and is in flow connection with the evacuation connection (30).
8. An apparatus according to claim 7, characterized in that the gas-permeable partition wall (33) is designed in the region of the peripheral wall (34) of the moulding box (6) as a slotted plate.
9. An apparatus according to claim 7 or 8, characterized in that the base plate (15) is composed of a material of relatively low heat resistance such as sintered plastic.
10. An apparatus according to any of claims 1 to 9, characterized in that the peripheral wall (34) of the moulding box (6) bounding the moulding material is designed as tapering upwards, starting from an equator plane (35) lying in a region midway up.
11. An apparatus according to any of claims 1 to 10, characterized in that the peripheral wall (34) of the moulding box (6) bounding the moulding material (13) is designed as tapering downwards, starting from an equator plane (35) lying in a region midway up, in particular if a vibratory device (29) is used.
12. An apparatus according to any of claims 1 to 11, characterized in that each moulding box (6) additionally has an evacuation connection (38) for negative pressure generation in the moulding material (13) and for extraction of the combustion gases from the latter, which evacuation connection opens out in the region of the equator plane (35) into a chamber (37) which is limited towards the moulding material (13) by a peripheral ring of a slotted plate forming the partition wall (36).
EP85106440A 1984-06-22 1985-05-24 Installation for carrying out a full-mould casting process Expired EP0166228B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85106440T ATE36476T1 (en) 1984-06-22 1985-05-24 EQUIPMENT FOR CARRYING OUT THE FULL MOLD CASTING PROCESS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3423199 1984-06-22
DE3423199A DE3423199C1 (en) 1984-06-22 1984-06-22 Device for the implementation of the full molding process

Publications (3)

Publication Number Publication Date
EP0166228A2 EP0166228A2 (en) 1986-01-02
EP0166228A3 EP0166228A3 (en) 1986-09-17
EP0166228B1 true EP0166228B1 (en) 1988-08-17

Family

ID=6238976

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85106440A Expired EP0166228B1 (en) 1984-06-22 1985-05-24 Installation for carrying out a full-mould casting process

Country Status (4)

Country Link
EP (1) EP0166228B1 (en)
JP (1) JPS6114046A (en)
AT (1) ATE36476T1 (en)
DE (2) DE3423199C1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102078916A (en) * 2010-12-29 2011-06-01 陈祥坤 Wax injector

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62207532A (en) * 1986-03-10 1987-09-11 Ube Ind Ltd Casting device
DE3707467C1 (en) * 1987-03-09 1988-08-04 Schubert & Salzer Maschinen Full molding process and device
US4736787B1 (en) * 1987-06-29 1999-11-16 Vulcan Engineering Co Lost foam handling system
JPH01202339A (en) * 1988-02-03 1989-08-15 Morikawa Sangyo Kk Method for pouring casting and apparatus for using to same
FR2645778B1 (en) * 1989-04-18 1991-06-07 Renault LOST MODEL CASTING TRAY
GB8913168D0 (en) * 1989-06-08 1989-07-26 Cook William Plc Foundry equipment
BR9503807A (en) * 1994-08-30 1996-09-10 Koji Hirokawa Stamping die combination of a stamping die with a die casting die casting process to produce a die casting die casting process to produce a hollow aluminum piston and piston for an internal combustion engine
DE19949500B4 (en) * 1999-10-14 2007-07-05 Volkswagen Ag Process for the serial production of metal castings using the lost-foam process
CN104707970B (en) * 2015-03-09 2017-01-11 江苏省沙钢钢铁研究院有限公司 Vacuum casting system for producing master alloy
CN104923767A (en) * 2015-06-30 2015-09-23 林怀敏 Vacuum casting electric heating sand box
CN112008039B (en) * 2020-08-26 2024-06-04 合肥天鹅制冷科技有限公司 Liquid cooling device used after wax pattern molding

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH334017A (en) * 1955-07-18 1958-11-15 Aluminium Ind Ag Ingot casting machine
DE1758521B1 (en) * 1968-06-19 1970-08-27 Gruenzweig & Hartmann Device for carrying out the full mold casting process
FR2071047A5 (en) * 1969-12-16 1971-09-17 Pont A Mousson
CH524415A (en) * 1970-04-20 1972-06-30 Gruenzweig & Hartmann Equipment for the implementation of the full mold casting process
FR2167458B1 (en) * 1972-01-13 1976-01-16 Anisa Sa Fr

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102078916A (en) * 2010-12-29 2011-06-01 陈祥坤 Wax injector
CN102078916B (en) * 2010-12-29 2012-11-21 陈祥坤 Wax injector

Also Published As

Publication number Publication date
DE3423199C1 (en) 1985-02-21
ATE36476T1 (en) 1988-09-15
EP0166228A3 (en) 1986-09-17
EP0166228A2 (en) 1986-01-02
JPS6114046A (en) 1986-01-22
DE3564389D1 (en) 1988-09-22

Similar Documents

Publication Publication Date Title
EP1192040B1 (en) Method and device for producing a three-dimensional object
EP1381504B1 (en) Method for unpacking shaped bodies embedded inside unbound particle material
EP0166228B1 (en) Installation for carrying out a full-mould casting process
DE60111190T2 (en) METHOD AND DEVICE FOR PRODUCING CAST FOAM BODIES
DE646937T1 (en) Permanent magnet manufacturing method and apparatus for forming a green compact.
DE1961234B2 (en) Method and device for compacting foundry molding compounds
DE2258461A1 (en) CASTING PROCESS
DE3507179C1 (en) Method and device for producing boxless molds
EP0281752B1 (en) Lost foam process and installation
EP0062331A1 (en) Method and apparatus for pneumatically compacting moulding sand
DE102016124387A1 (en) Baubox for the additive production of a molding and arrangement
DE3202395A1 (en) Process and equipment for pneumatic compaction of moulding sand
EP0995521B1 (en) Foundry moulding machine, method and use of the machine for the manufacture of sand moulds in flasks
DE2403199B2 (en)
DE3301562C1 (en) Device for making concrete blocks
DE69500442T2 (en) Method and device for manufacturing molded shells
DE1076901B (en) Method and device for producing casting molds
DE10321532A1 (en) Sand mold box machine has workstations to fill the boxes with sand and compress the sand filling, without recirculating or reciprocating filling frames to shorten cycle times and increase sand filling times
DE3318150C2 (en) Working container for blow molding and sand shooting machines
DE3002702A1 (en) Sand hopper for foundry moulding machine - where stationary press head is used to open or close sand outlet in base of vertically driven hopper
DE2554414A1 (en) METHOD AND DEVICE FOR MANUFACTURING SAND CASTING MOLDS
DE4319078C2 (en) Process and mold making machine for the production of molds or mold parts from molding sand
DE69101641T2 (en) Method and device for removing bricks from molded boxes.
DE2830479A1 (en) Concrete mould filling process - lowers component initially shutting off mould flush with top during filling
EP0126269B1 (en) Method of and installation for producing moulds

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT CH DE FR GB IT LI

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT CH DE FR GB IT LI

17P Request for examination filed

Effective date: 19861010

17Q First examination report despatched

Effective date: 19870226

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE FR GB IT LI

REF Corresponds to:

Ref document number: 36476

Country of ref document: AT

Date of ref document: 19880915

Kind code of ref document: T

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
REF Corresponds to:

Ref document number: 3564389

Country of ref document: DE

Date of ref document: 19880922

ET Fr: translation filed
ITF It: translation for a ep patent filed

Owner name: SOCIETA' ITALIANA BREVETTI S.P.A.

ITPR It: changes in ownership of a european patent

Owner name: CAMBIO RAGIONE SOCIALE;GRUENZWEIG + HARTMANN AG

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19890524

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19890531

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19890804

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19891030

Year of fee payment: 5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19900131

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19900524

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19900531

Ref country code: CH

Effective date: 19900531

GBPC Gb: european patent ceased through non-payment of renewal fee
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19910201