EP0463911A1 - Process, mould and device for low-pressure multi-stage casting of metal - Google Patents

Process, mould and device for low-pressure multi-stage casting of metal Download PDF

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Publication number
EP0463911A1
EP0463911A1 EP91401544A EP91401544A EP0463911A1 EP 0463911 A1 EP0463911 A1 EP 0463911A1 EP 91401544 A EP91401544 A EP 91401544A EP 91401544 A EP91401544 A EP 91401544A EP 0463911 A1 EP0463911 A1 EP 0463911A1
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EP
European Patent Office
Prior art keywords
well
mold
casting
stage
metal
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EP91401544A
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German (de)
French (fr)
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EP0463911B1 (en
Inventor
Pascal Sourlier
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Pont a Mousson SA
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Pont a Mousson SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/20—Stack moulds, i.e. arrangement of multiple moulds or flasks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D18/00—Pressure casting; Vacuum casting
    • B22D18/04—Low pressure casting, i.e. making use of pressures up to a few bars to fill the mould

Definitions

  • the present invention relates to metal casting under low pressure in a multi-stage blind sand mold. It relates firstly to a process for supplying the imprints of a mold in blind sand with several stages, in metal casting under low pressure, the supply taking place via a casting well and, on each stage, at least one intermediate channel starting from this well and attacks connecting this channel to the or each footprint.
  • the low pressure casting technique (see for example FR-A-2 295 808, 2 367 566 and 2 556 996 in the name of the Applicant) is particularly advantageous, compared to gravity casting, for producing metal parts with thin wall and / or of complex shape and / or of large dimensions. Indeed, the pressure exerted by the metal, which results from the injection of a gas into a sealed pocket containing the liquid metal, can be controlled at will so as to push the metal into all the recesses of the imprints.
  • the method according to the invention aims to remedy these drawbacks.
  • the method according to the invention is characterized in that the flow of liquid metal is throttled, on each stage, at the inlet of the intermediate channels.
  • the invention also relates to a blind sand mold intended for the implementation of such a method.
  • This mold of the type comprising a pouring well and at least two stages at each of which is provided at least one imprint supplied via attacks connected to the tapping well by at least one intermediate channel, is characterized in that the sum of the areas of the inlet sections of the intermediate channels of each stage is significantly less than the area of the section of the tapping well.
  • the invention also relates to a low pressure metal casting installation in a blind sand mold with several floors, of the type comprising a casting ladle from which a feed tube opens upwards, a gas source under pressure connected to the ladle, at least one blind sand mold comprising a casting well open at the bottom and at least two stages on each of which is provided at least one footprint fed via attacks connected to the casting well by at least one intermediate channel, and means for applying the base of the tapping well to the opening of the supply tube, characterized in that the mold conforms to the definition above.
  • the installation shown in Fig. 1 comprises an enclosure 1 forming a pocket or reserve of liquid metal 2, a frame 3 for mold support and a sand mold 4. It is applied to low pressure casting of cast iron (gray cast iron or spheroidal graphite cast iron), steel or a superalloy in the mold 4. Apart from the internal configuration of this mold, the installation is identical to that described in the aforementioned FR-A-2 295 808.
  • the pocket 1, fixed has an upper cover 5 tightly fixed to its side walls and locked by suitable means (not shown).
  • a pouring nozzle 6 passes through an orifice 7 formed in the cover 5.
  • This nozzle 6 comprises a tubular lower part 8 whose outside diameter corresponds to the diameter of the orifice 7 and an upper part 9, of generally frustoconical shape, which s' presses tightly on the periphery of the orifice 7 by its large flat base 10.
  • a seal 11 formed by an asbestos bead is housed in a groove formed in the base 10 of the nozzle.
  • the nozzle 6 is traversed by a conduit or supply tube 12 made of refractory material dipping into the cast iron up to the vicinity of the bottom of the pocket 1; the upper part of the duct 12 opens out at the center of the nozzle 6, at the level of the planar upper face of the latter.
  • the bag 1 is connected to a source 13 of pressurized gas by a conduit 14, the communication of the bag 1 with the pressure source 13 or with the atmosphere effected by a suitable device 15 outside the bag.
  • a pressure gauge 16 makes it possible to monitor the pressure prevailing inside the pocket during pouring.
  • the frame 3 comprises posts 17 provided at their base with wheels 18 carried by two rails 19.
  • the posts 17 are joined at their upper end by a ceiling 20 carrying a jack 21 directed downwards and whose piston rod 22 carries, articulated at its lower end, a support plate 23.
  • the posts 17 also each carry a flange 24 on which a helical spring 25 rests.
  • a horizontal support plate 26 can slide vertically along part of the: posts 17 located above the flanges 24; this plate 26 is in constant abutment on the upper end of the springs 25 and is urged by them upwards. When no downward pressure is applied to the plate 26, the latter is at a level higher than that of the upper face of the nozzle 6.
  • a circular opening 27, of sufficient diameter to allow the nozzle 6 to pass is provided in the plate 26.
  • the mold 4 is a solid multi-stage blind mold, for example with three stages, as shown in FIG. 2. It comprises a vertical pouring well 28, of circular section approximately equal to that of the supply tube 12. This well is open at its base, which has a housing 29 having a tapered flared shape combined with that of the nozzle 6. It extends to a certain distance from the upper end face of the mold.
  • each stage is identical, and the structure of each stage appears in FIG. 3. From the casting well 28, two channels 30A and 30B leave horizontally, which extend in the extension of one another, on either side of the well 28.
  • the stage also comprises two indentations 31 of elongated shape , identical.
  • Each footprint, which extends on either side of the well 28, is fed by three attacks. In the example shown, there is for each fingerprint an attack 32A on one side of the well and two attacks 32B on the other side.
  • the three attacks 32A connect the fingerprints to channel 30A, and the three attacks 32B connect them to channel 30B.
  • each channel 30A or 30B connects the casting well to all: the attacks located on the same side of the well 28 and therefore participates in the supply of the two footprints of the floor.
  • Channels 30A and 30B have a relatively small section. More precisely, the sum of the areas of the sections of the intermediate channels 30A, 30B of a stage is much less than the area of the section of the taphole 28, for example less than 10% of this area. If the channels are of variable section, it is their input section which fulfills this condition.
  • the sum of the areas of the attack sections fed by the same channel is at least equal to the area of the section, or of the entry section, of this channel.
  • the operation of the installation is as follows: the frame 3 being distant from the pocket 1, an appropriate refractory seal 33 is applied to the bottom of the housing 29 of the mold 4.
  • the mold 4, containing in each cavity a non-core shown, is placed on the plate 26 and centered on the opening 27 thereof, then the frame 3 is brought to the rails 19 above the pocket 1 of liquid iron so that the nozzle 6 is located opposite the housing 29 of the mold.
  • the jack 21 is then extended so as to lower, by means of the plate: 23, the mold 4 and its support 26 against the force of the springs 25. This operation clamps the seal 33 between the bottom of the housing 29 and the nozzle 6 and ensures the tight connection of the pouring well to the supply tube.
  • the bag 1 is then connected to the pressure source 13 by operating the device 15.
  • the pressure acting on the free surface of the cast iron makes it rise in the tube 12.
  • the cast iron fills the well 28 of the mold, the channels 30A and 30B and the imprints 31.
  • the pressure is maintained for a time determined according to the dimensions and the shapes of the parts to be obtained.
  • the well 28 plays during this time the role of reserve or counterweight by bringing to the imprints the additional liquid cast iron intended to compensate for the withdrawals.
  • the attacks and the intermediate channels solidify, the gas pressure is brought back to atmospheric pressure in the pocket 1, by operation of the device 15, and the liquid iron being in the well 28 and in the tube 12 goes back down in the pocket 1 by evacuating these two conduits.
  • the liquid metal rises rapidly in well 28, the metallostatic pressure is established in the channels on each stage, and the two cavities of each stage are supplied by the pair of channels 30A and 30B corresponding.
  • the narrowness of the intermediate channels limits the flow of metal flowing therein, which leads on the one hand to a better controlled filling, quieter and reproducible for each of the imprints of the different stages, and on the other hand minimal metal displacement with each pour. This is further favored by the relaxation of the liquid metal at its entry into the attacks, resulting from the aforementioned dimensioning of these. This ultimately results in an improvement in the health of the castings.
  • the relaxing effect of the metal can, as a variant, be favored by an increasing section, from upstream to downstream, of the intermediate channels.

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  • Mechanical Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Casting Devices For Molds (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
  • Mold Materials And Core Materials (AREA)
  • Continuous Casting (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Producing Shaped Articles From Materials (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)

Abstract

At each stage of the mould (4), the sum of the areas of the inlet cross-sections of the intermediate channels (30A, 30B) which feed the casting runners (32A, 32B) is markedly smaller than the area of the cross-section of the casting pool. Application to the multi-stage casting of thin-wall castings. <IMAGE>

Description

La présente invention est relative à la coulée de métal sous basse pression en moule en sable borgne multi-étages. Elle concerne en premier lieu un procédé pour alimenter les empreintes d'un moule en sable borgne à plusieurs étages, en coulée de métal sous basse pression, l'alimentation s'effectuant via un puits de coulée et, à chaque étage, au moins un canal intermédiaire partant de ce puits et des attaques reliant ce canal à la ou à chaque empreinte.The present invention relates to metal casting under low pressure in a multi-stage blind sand mold. It relates firstly to a process for supplying the imprints of a mold in blind sand with several stages, in metal casting under low pressure, the supply taking place via a casting well and, on each stage, at least one intermediate channel starting from this well and attacks connecting this channel to the or each footprint.

La technique de coulée sous basse pression (voir par exemple les FR-A-2 295 808, 2 367 566 et 2 556 996 au nom de la Demanderesse) est particulièrement avantageuse, par rapport à la coulée gravitaire, pour réaliser des pièces métalliques à paroi mince et/ou de forme complexe et/ou de grandes dimensions. En effet, la pression exercée par le métal, qui résulte de l'injection d'un gaz dans une poche étanche contenant le métal liquide, peut être commandée à volonté de façon à pousser le métal dans tous les recoins des empreintes.The low pressure casting technique (see for example FR-A-2 295 808, 2 367 566 and 2 556 996 in the name of the Applicant) is particularly advantageous, compared to gravity casting, for producing metal parts with thin wall and / or of complex shape and / or of large dimensions. Indeed, the pressure exerted by the metal, which results from the injection of a gas into a sealed pocket containing the liquid metal, can be controlled at will so as to push the metal into all the recesses of the imprints.

Dans la technique classique, à chaque étage du moule, un canal intermédiaire unique de grande section, ou deux canaux intermédiaires de grande section diamétralement opposés, relient le puits de coulée à l'ensemble des attaques de l'étage.In the conventional technique, on each stage of the mold, a single intermediate channel of large cross section, or two intermediate channels of large cross section diametrically opposite, connect the pouring well to all of the attacks of the stage.

Cette manière de faire présente les inconvénients suivants, liés à la grande section du ou des canaux.

  • (1) Il se crée de fortes turbulences dans le flot de métal, ce qui favorise l'érosion du sable et l'occlusion de bulles d'air, au détriment de la santé des pièces obtenues.
  • (2) Il n'est pas possible de faire monter rapidement le métal jusqu'au sommet du puits de coulée, et le remplissage s'effectue en fait étage par étage, ce quine permet pas de bénéficier de tous les avantages de la coulée basse pression.
  • (3) Lorsque la pression est relâchée, après solidification des attaques qui forment obturateurs (voir le FR-A-2 295 808 précité), le métal contenu dans le canal intermédiaire, représentant un volume relativement grand qui s'est notablement refroidi, retourne dans la poche de coulée. A la coulée suivante, c'est du métal moins chaud qui monte en premier dans le puits de coulée, ce qui nuit à la qualité de certaines pièces moulées. Pour la même raison, un déplacement de métal excessif est nécessaire à chaque coulée.
This approach has the following drawbacks, linked to the large section of the channel (s).
  • (1) Strong turbulence is created in the metal flow, which promotes the erosion of the sand and the occlusion of air bubbles, to the detriment of the health of the parts obtained.
  • (2) It is not possible to quickly raise the metal to the top of the well, and the filling is done in fact stage by stage, which does not allow to benefit from all the advantages of low pressure casting.
  • (3) When the pressure is released, after solidification of the attacks which form obturators (see FR-A-2 295 808 cited above), the metal contained in the intermediate channel, representing a relatively large volume which has notably cooled, returns in the ladle. At the next casting, less warm metal rises first in the casting well, which affects the quality of some molded parts. For the same reason, excessive metal displacement is necessary for each casting.

L'invention a pour but de remédier à ces inconvénients. A cet effet, le procédé suivant l'invention est caractérisé en ce qu'on étrangle le débit de métal liquide, à chaque étage, à l'entrée des canaux intermédiaires.The invention aims to remedy these drawbacks. To this end, the method according to the invention is characterized in that the flow of liquid metal is throttled, on each stage, at the inlet of the intermediate channels.

Suivant d'autres caractéristiques :

  • on détend le métal liquide après son entrée dans les canaux intermédiaires, notamment lors de son entrée dans les attaques ;
  • on envoie dans le tube d'amenée un débit de métal liquide adapté pour provoquer une montée de ce métal au-dessus de tous les canaux intermédiaires ;
  • on maintient la pression d'alimentation du moule jusqu'à solidification de tous les canaux intermédiaires, puis on relâche cette pression.
According to other characteristics:
  • the liquid metal is relaxed after it enters the intermediate channels, in particular when it enters the attacks;
  • a flow of liquid metal adapted to cause this metal to rise above all of the intermediate channels is sent into the supply tube;
  • the supply pressure of the mold is maintained until all the intermediate channels solidify, then this pressure is released.

L'invention a également pour objet un moule en sable borgne destiné à la mise en oeuvre d'un tel procédé. Ce moule, du type comprenant un puits de coulée et au moins deux étages à chacun desquels est prévue au moins une empreinte alimentée via des attaques reliées au puits de coulée par au moins un canal intermédiaire, est caractérisé en ce que la somme des aires des sections d'entrée des canaux intermédiaires de chaque étage est nettement inférieure à l'aire de la section du puits de coulée.The invention also relates to a blind sand mold intended for the implementation of such a method. This mold, of the type comprising a pouring well and at least two stages at each of which is provided at least one imprint supplied via attacks connected to the tapping well by at least one intermediate channel, is characterized in that the sum of the areas of the inlet sections of the intermediate channels of each stage is significantly less than the area of the section of the tapping well.

Suivant d'autres caractéristiques :

  • la somme des aires des sections des attaques alimentées par un même canal est au moins égale à l'aire de la section d'entrée de ce canal ;
  • chaque empreinte est alimentée par au moins deux canaux intermédiaires s'étendant de part et d'autre du puits de coulée ;
  • la somme des aires des sections d'entrée des canaux intermédiaires de chaque étage est inférieure à 10 % de l'aire de la section du puits de coulée.
According to other characteristics:
  • the sum of the areas of the attack sections fed by the same channel is at least equal to the area of the entry section of this channel;
  • each footprint is fed by at least two intermediate channels extending on either side of the well;
  • the sum of the areas of the inlet sections of the intermediate canals of each stage is less than 10% of the area of the section of the taphole.

L'invention a encore pour objet une installation de coulée de métal sous basse pression en moule en sable borgne à plusieurs étages, du type comprenant une poche de coulée d'où part un tube d'amenée ouvert vers le haut, une source de gaz sous pression reliée à la poche, au moins un moule en sable borgne comprenant un puits de coulée ouvert vers le bas et au moins deux étages à chacun desquels est prévue au moins une empreinte alimentée via des attaques reliées au puits de coulée par au moins un canal intermédiaire, et des moyens pour appliquer la base du puits de coulée sur l'ouverture du tube d'amenée, caractérisée en ce que le moule est conforme à la définition ci-dessus.The invention also relates to a low pressure metal casting installation in a blind sand mold with several floors, of the type comprising a casting ladle from which a feed tube opens upwards, a gas source under pressure connected to the ladle, at least one blind sand mold comprising a casting well open at the bottom and at least two stages on each of which is provided at least one footprint fed via attacks connected to the casting well by at least one intermediate channel, and means for applying the base of the tapping well to the opening of the supply tube, characterized in that the mold conforms to the definition above.

Un exemple non limitatif de mise en oeuvre de l'invention va maintenant être décrit en regard des dessins annexés sur lesquels :

  • la Fig. 1 représente schématiquement, en coupe verticale, une installation de coulée conforme à l'invention ;
  • la Fig. 2 représente un moule utilisé dans cette installation, en coupe suivant la ligne II-II de la Fig. 3 ; et
  • la Fig. 3 est une vue prise en coupe suivant la ligne III-III de la Fig. 2.
A nonlimiting example of implementation of the invention will now be described with reference to the appended drawings in which:
  • Fig. 1 schematically represents, in vertical section, a casting installation in accordance with the invention;
  • Fig. 2 shows a mold used in this installation, in section along line II-II of FIG. 3; and
  • Fig. 3 is a view taken in section along line III-III of FIG. 2.

L'installation présentée à la Fig. 1 comporte une enceinte 1 formant une poche ou réserve de métal liquide 2, un bâti 3 de support de moule et un moule en sable 4. Elle est appliquée à la coulée sous basse pression de fonte (fonte grise ou fonte à graphite sphéroïdal), d'acier ou d'un superalliage dans le moule 4. A part la configuration interne de ce moule, l'installation est identique à celle décrite dans le FR-A-2 295 808 précité.The installation shown in Fig. 1 comprises an enclosure 1 forming a pocket or reserve of liquid metal 2, a frame 3 for mold support and a sand mold 4. It is applied to low pressure casting of cast iron (gray cast iron or spheroidal graphite cast iron), steel or a superalloy in the mold 4. Apart from the internal configuration of this mold, the installation is identical to that described in the aforementioned FR-A-2 295 808.

La poche 1, fixe, comporte un couvercle supérieur 5 fixé de façon étanche à ses parois latérales et verrouillé par des moyens appropriés (non représentés). Une buse de coulée 6 traverse un orifice 7 ménagé dans le couvercle 5. Cette buse 6 comporte une partie inférieure tubulaire 8 dont le diamètre extérieur correspond au diamètre de l'orifice 7 et une partie supérieure 9, de forme générale tronconique, qui s'appuie de façon étanche sur la périphérie de l'orifice 7 par sa grande base plane 10. Une garniture d'étanchéité 11 constituée par un cordon d'amiante est logée dans une gorge ménagée dans la base 10 de la buse. La buse 6 est traversée par un conduit ou tube d'amenée 12 en matériau réfractaire plongeant dans la fonte jusqu'au voisinage du fond de la poche 1 ; la partie supérieure du conduit 12 débouche au centre de la buse 6, au niveau de la face supérieure plane de celle-ci.The pocket 1, fixed, has an upper cover 5 tightly fixed to its side walls and locked by suitable means (not shown). A pouring nozzle 6 passes through an orifice 7 formed in the cover 5. This nozzle 6 comprises a tubular lower part 8 whose outside diameter corresponds to the diameter of the orifice 7 and an upper part 9, of generally frustoconical shape, which s' presses tightly on the periphery of the orifice 7 by its large flat base 10. A seal 11 formed by an asbestos bead is housed in a groove formed in the base 10 of the nozzle. The nozzle 6 is traversed by a conduit or supply tube 12 made of refractory material dipping into the cast iron up to the vicinity of the bottom of the pocket 1; the upper part of the duct 12 opens out at the center of the nozzle 6, at the level of the planar upper face of the latter.

La poche 1 est reliée à une source 13 de gaz sous pression par un conduit 14, la mise en communication de la poche 1 avec la source de pression 13 ou avec l'atmosphère s'effectuant par un dispositif approprié 15 extérieur à la poche. Un manomètre 16 permet de surveiller la pression régnant à l'intérieur de la poche lors de la coulée.The bag 1 is connected to a source 13 of pressurized gas by a conduit 14, the communication of the bag 1 with the pressure source 13 or with the atmosphere effected by a suitable device 15 outside the bag. A pressure gauge 16 makes it possible to monitor the pressure prevailing inside the pocket during pouring.

Le bâti 3 comprend des poteaux 17 munis à leur base de roues 18 portées par deux rails 19.The frame 3 comprises posts 17 provided at their base with wheels 18 carried by two rails 19.

Les poteaux 17 sont réunis à leur extrémité supérieure par un plafond 20 portant un vérin 21 dirigé vers le bas et dont la tige de piston 22 porte, articulée à son extrémité inférieure, une plaque il'appui 23.The posts 17 are joined at their upper end by a ceiling 20 carrying a jack 21 directed downwards and whose piston rod 22 carries, articulated at its lower end, a support plate 23.

Les poteaux 17 portent également chacun une collerette 24 sur laquelle s'appuie un ressort hélicoîdal 25. Une plaque de support 26 horizontale peut coulisser verticalement le long d'une partie des: poteaux 17 située au-dessus des collerettes 24 ; cette plaque 26 est en appui constant sur l'extrémité supérieure des ressorts 25 et est sollicitée par ceux-ci vers le haut. Lorsqu'aucune pression vers le bas n'est appliquée à la plaque 26, celle-ci se trouve à un niveau supérieur à celui de la face supérieure de la buse 6. Une ouverture circulaire 27, de diamètre suffisant pour laisser passer la buse 6, est ménagée dans la plaque 26.The posts 17 also each carry a flange 24 on which a helical spring 25 rests. A horizontal support plate 26 can slide vertically along part of the: posts 17 located above the flanges 24; this plate 26 is in constant abutment on the upper end of the springs 25 and is urged by them upwards. When no downward pressure is applied to the plate 26, the latter is at a level higher than that of the upper face of the nozzle 6. A circular opening 27, of sufficient diameter to allow the nozzle 6 to pass , is provided in the plate 26.

Le moule 4 est un moule borgne massif multiétage, par exemple à trois étages, comme représenté sur la Fig. 2. Il comprend un puits de coulée 28 vertical, de section circulaire à peu près égale à celle du tube d'amenée 12. Ce puits est ouvert à sa base, qui présente un logement 29 ayant une forme évasée tronconique conjuguée de celle de la buse 6. Il s'étend jusqu'à une certaine distance de la face d'extrémité supérieure du moule.The mold 4 is a solid multi-stage blind mold, for example with three stages, as shown in FIG. 2. It comprises a vertical pouring well 28, of circular section approximately equal to that of the supply tube 12. This well is open at its base, which has a housing 29 having a tapered flared shape combined with that of the nozzle 6. It extends to a certain distance from the upper end face of the mold.

Les trois étages sont identiques, et la structure de chaque étage apparaît sur la Fig. 3. Du puits de coulée 28 partent horizontalement deux canaux 30A et 30B qui s'étendent dans le prolongement l'un de l'autre, de part et d'autre du puits 28. L'étage comprend encore deux empreintes 31 de forme allongée, identiques. Chaque empreinte, qui s'étend de part et d'autre du puits 28, est alimentée par trois attaques. Dans l'exemple représenté, il y a pour chaque empreinte une attaque 32A d'un côté du puits et deux attaques 32B de l'autre côté. Les trois attaques 32A relient les empreintes au canal 30A, et les trois attaques 32B les relient au canal 30B. Ainsi, chaque canal 30A ou 30B relie le puits de coulée à toutes: les attaques situées du mêe côté du puits 28 et participe donc à l'alimentation des deux empreintes de l'étage.The three stages are identical, and the structure of each stage appears in FIG. 3. From the casting well 28, two channels 30A and 30B leave horizontally, which extend in the extension of one another, on either side of the well 28. The stage also comprises two indentations 31 of elongated shape , identical. Each footprint, which extends on either side of the well 28, is fed by three attacks. In the example shown, there is for each fingerprint an attack 32A on one side of the well and two attacks 32B on the other side. The three attacks 32A connect the fingerprints to channel 30A, and the three attacks 32B connect them to channel 30B. Thus, each channel 30A or 30B connects the casting well to all: the attacks located on the same side of the well 28 and therefore participates in the supply of the two footprints of the floor.

Les canaux 30A et 30B ont une section relativement petite. Plus précisément, la somme des aires des sections des canaux intermédiaires 30A, 30B d'un étage est nettement inférieure à l'aire de la section du puits de coulée 28, par exemple inférieure à 10 % de cette aire. Si les canaux sont à section variable, c'est leur section d'entrée qui remplit cette condition.Channels 30A and 30B have a relatively small section. More precisely, the sum of the areas of the sections of the intermediate channels 30A, 30B of a stage is much less than the area of the section of the taphole 28, for example less than 10% of this area. If the channels are of variable section, it is their input section which fulfills this condition.

En outre, la somme des aires des sections des attaques alimentées par un même canal est au moins égale à l'aire de la section, ou de la section d'entrée, de ce canal.In addition, the sum of the areas of the attack sections fed by the same channel is at least equal to the area of the section, or of the entry section, of this channel.

Le fonctionnement de l'installation est le suivant : le bâti 3 étant éloigné de la poche 1, un joint d'étanchéité réfractaire approprié 33 est appliqué au fond du logement 29 du moule 4. Le moule 4, contenant dans chaque empreinte un noyau non représenté, est placé sur la plaque 26 et centré sur l'ouverture 27 de celle-ci, puis le bâti 3 est amené sur les rails 19 au-dessus de la poche 1 de fonte liquide de façon que la buse 6 se trouve en regard du logement 29 du moule. Le vérin 21 est alors mis en extension de façon à abaisser, par l'intermédiaire de la plaque: 23, le moule 4 et son support 26 à l'encontre de la force des ressorts 25. Cette opération serre le joint 33 entre le fond du logement 29 et la buse 6 et assure la liaison étanche du puits de coulée au tube d'amenée.The operation of the installation is as follows: the frame 3 being distant from the pocket 1, an appropriate refractory seal 33 is applied to the bottom of the housing 29 of the mold 4. The mold 4, containing in each cavity a non-core shown, is placed on the plate 26 and centered on the opening 27 thereof, then the frame 3 is brought to the rails 19 above the pocket 1 of liquid iron so that the nozzle 6 is located opposite the housing 29 of the mold. The jack 21 is then extended so as to lower, by means of the plate: 23, the mold 4 and its support 26 against the force of the springs 25. This operation clamps the seal 33 between the bottom of the housing 29 and the nozzle 6 and ensures the tight connection of the pouring well to the supply tube.

La poche 1 est ensuite reliée à la source de pression 13 par manoeuvre du dispositif 15. La pression agissant sur la surface libre de la fonte fait monter celle-ci dans le tube 12. La fonte remplit le puits 28 du moule, les canaux 30A et 30B et les empreintes 31. La pression est maintenue pendant un temps déterminé en fonction des dimensions et des formes des pièces à obtenir. Le puits 28 joue pendant ce temps le rôle de réserve ou de masselotte en apportant aux empreintes la fonte liquide supplémentaire destinée à compenser les retraits. Puis les attaques et les canaux intermédiaires se solidifient, la pression de gaz est ramenée à la pression atmosphérique dans la poche 1, par manoeuvre du dispositif 15, et la fonte liquide se trouvant dans le puits 28 et dans le tube 12 redescend dans la poche 1 en évacuant ces deux conduits.The bag 1 is then connected to the pressure source 13 by operating the device 15. The pressure acting on the free surface of the cast iron makes it rise in the tube 12. The cast iron fills the well 28 of the mold, the channels 30A and 30B and the imprints 31. The pressure is maintained for a time determined according to the dimensions and the shapes of the parts to be obtained. The well 28 plays during this time the role of reserve or counterweight by bringing to the imprints the additional liquid cast iron intended to compensate for the withdrawals. Then the attacks and the intermediate channels solidify, the gas pressure is brought back to atmospheric pressure in the pocket 1, by operation of the device 15, and the liquid iron being in the well 28 and in the tube 12 goes back down in the pocket 1 by evacuating these two conduits.

L'action du vérin 21 est alors supprimée, l'ensemble moule-support 26 est écarté de la buse 6 sous l'action des ressorts 25, et l'ensemble du bâti 3 est éloigné horizontalement de la poche sur les rails 19The action of the jack 21 is then eliminated, the mold-support assembly 26 is moved away from the nozzle 6 under the action of the springs 25, and the assembly of the frame 3 is moved horizontally from the pocket on the rails 19

Grâce au dimensionnement des canaux 30A, 30B indiqué plus haut et en assurant par le conduit 14 un débit de gaz approprié, le métal liquide monte rapidement dans le puits 28, la pression métallostatique s'établit dans les canaux à chaque étage, et les deux empreintes de chaque étage sont alimentées par le couple de canaux 30A et 30B correspondant. Ceci permet d'obtenir un remplissage simultané de toutes les empreintes, quelle que soit leur forme. De plus, l'étroitesse des canaux intermédiaires limite le débit de métal qui s'y écoule, ce qui conduit d'une part à un remplissage mieux contrôlé, plus calme et reproductible pour chacune des empreintes des différents étages, et d'autre part à un déplacement minimal de métal à chaque coulée. Ceci est encore favorisé par la détente du métal liquide à son entrée dans les attaques, résultant du dimensionnement précité de celles-ci.. Il en résulte finalement une amélioration de la santé des pièces coulées.Thanks to the dimensioning of the channels 30A, 30B indicated above and by ensuring through the duct 14 an appropriate gas flow, the liquid metal rises rapidly in well 28, the metallostatic pressure is established in the channels on each stage, and the two cavities of each stage are supplied by the pair of channels 30A and 30B corresponding. This makes it possible to simultaneously fill all the imprints, whatever their shape. In addition, the narrowness of the intermediate channels limits the flow of metal flowing therein, which leads on the one hand to a better controlled filling, quieter and reproducible for each of the imprints of the different stages, and on the other hand minimal metal displacement with each pour. This is further favored by the relaxation of the liquid metal at its entry into the attacks, resulting from the aforementioned dimensioning of these. This ultimately results in an improvement in the health of the castings.

L'effet de détente du métal peut, en variante, être favorisé par une section croissante, d'amont vers l'aval, des canaux intermédiaires.The relaxing effect of the metal can, as a variant, be favored by an increasing section, from upstream to downstream, of the intermediate channels.

Il faut encore noter que l'utilisation des canaux intermédiaires comme obturateurs évite tout retour de métal notablement refroidi dans la poche, sans réduire le rendement en métal. Ceci est très avantageux pour la reproductibilité des conditions de coulée. De plus, le métal légèrement refroidi contenu dans le puits de coulée est, à la coulée suivante, réparti entre toutes les empreintes du moule.It should also be noted that the use of intermediate channels as plugs prevents any return of significantly cooled metal in the pocket, without reducing the yield of metal. This is very advantageous for the reproducibility of the casting conditions. In addition, the slightly cooled metal contained in the pouring well is, on the next casting, distributed among all of the mold cavities.

Claims (10)

Procédé pour alimenter les empreintes (31) d'un moule en sable borgne (4) à plusieurs étages, en coulée de métal sous basse pression, l'alimentation s'effectuant via un puits de coulée (28) et, à chaque étage, au moins un canal intermédiaire 30A, 30B) partant de ce puits et des attaques (32A, 32B), reliant ce canal à la ou à chaque empreinte, caractérisé en ce qu'on étrangle le débit de métal liquide, à chaque étage, à l'entrée des canaux intermédiaires.Method for feeding the cavities (31) of a blind sand mold (4) with several stages, in metal casting under low pressure, the supply taking place via a pouring well (28) and, on each stage, at least one intermediate channel 30A, 30B) starting from this well and the attacks (32A, 32B), connecting this channel to the or each imprint, characterized in that the flow of liquid metal is throttled, on each stage, at the entrance to the intermediate canals. Procédé suivant la revendication 1, caractérisé en ce qu'on détend le métal liquide après son entrée dans les canaux intermédiaires (30A, 30B).Method according to claim 1, characterized in that the liquid metal is expanded after it has entered the intermediate channels (30A, 30B). Procédé suivant la revendication 2, caractérisé en ce qu'on détend le métal liquide lors de son entrée dans les attaques (32A, 32B).Method according to claim 2, characterized in that the liquid metal is relaxed when it enters the attacks (32A, 32B). Procédé suivant l'une quelconque des revendications 1 à 3, caractérisé en ce qu'on envoie dans le tube d'amenée un débit de métal liquide adapté pour provoquer une montée de ce métal au-dessus de tous les canaux intermédiaires (30A, 30B).Process according to any one of Claims 1 to 3, characterized in that a flow of liquid metal adapted to cause a rise of this metal over all of the intermediate channels (30A, 30B) is sent into the supply tube. ). Procédé suivant l'une quelconque des revendications 1 à 4, caractérisé en ce qu'on maintient la pression d'alimentation du moule jusqu'à solidification de tous les canaux intermédiaires (30A, 30B), puis on relâche cette pression.Process according to any one of Claims 1 to 4, characterized in that the supply pressure of the mold is maintained until all the intermediate channels (30A, 30B) solidify, then this pressure is released. Moule en sable borgne pour la mise en oeuvre d'un procédé suivant l'une quelconque des revendications 1 à 5, du type comprenant un puis de coulée (28) et au moins deux étages à chacun desquels est prévue au moins une empreinte (31) alimentée via des attaques (32A, 32B) reliées au puits de coulée par au moins un canal intermédiaire (30A, 30B), caractérisé en ce que la somme des aires des sections d'entrée des canaux intermédiaires de chaque étage est nettement inférieure à l'aire de la section du puits de coulée.Mold in blind sand for the implementation of a method according to any one of claims 1 to 5, of the type comprising a pouring well (28) and at least two stages on each of which is provided at least one cavity (31 ) supplied via attacks (32A, 32B) connected to the tapping well by at least one intermediate channel (30A, 30B), characterized in that the sum of the areas of the inlet sections intermediate channels of each stage is significantly less than the cross-sectional area of the tapping well. Moule en sable suivant la revendication 6, caractérisé en ce que la somme des aires des sections des attaques (32A, 32B) alimentées par un même canal (30A, 30B) est au moins égale à l'aire de la section d'entrée de ce canal.Sand mold according to claim 6, characterized in that the sum of the areas of the attack sections (32A, 32B) supplied by the same channel (30A, 30B) is at least equal to the area of the entry section of this channel. Moule en sable suivant la revendication 6 ou 7, caractérisé en ce que chaque empreinte (31) est alimentée par au moins deux canaux intermédiaires (30A, 30B) s'étendant de part et d'autre du puits de coulée (28).Sand mold according to claim 6 or 7, characterized in that each cavity (31) is supplied by at least two intermediate channels (30A, 30B) extending on either side of the casting well (28). Moule suivant l'une quelconque des revendications 6 à 8, caractérisé en ce que la somme des aires des sections d'entrée des canaux intermédiaires (30A, 30B) de chaque étage est inférieure à 10 % de l'aire de la section du puits de coulée (28).Mold according to any one of Claims 6 to 8, characterized in that the sum of the areas of the inlet sections of the intermediate channels (30A, 30B) of each stage is less than 10% of the area of the section of the well casting (28). Installation de coulée de métal sous basse pression en moule en sable borgne à plusieurs étages, du type comprenant une poche de coulée (1) d'où part un tube d'amenée (12) ouvert vers le haut, une source (13) de gaz sous pression reliée à la poche, au moins un moule en sable borgne (4) comprenant un puits de coulée (28) ouvert vers le bas et au moins deux étages à chacun desquels est prévue au moins une empreinte (31) alimentée via des attaques (32A, 32B) reliées au puits de coulée par au moins un canal intermédiaire (30A, 30B), et des moyens (21) pour appliquer la base du puits de coulée sur l'ouverture du tube d'amenée, caractérisé en ce que le moule est conforme à l'une quelconque des revendications 6 à 9.Installation of low pressure metal casting in a multi-stage blind sand mold, of the type comprising a casting ladle (1) from which a supply tube (12) open upwards, a source (13) of pressurized gas connected to the ladle, at least one blind sand mold (4) comprising a pouring well (28) open downwards and at least two stages at each of which is provided at least one cavity (31) supplied via attacks (32A, 32B) connected to the tapping well by at least one intermediate channel (30A, 30B), and means (21) for applying the base of the tapping well to the opening of the supply tube, characterized in that that the mold conforms to any one of claims 6 to 9.
EP91401544A 1990-06-22 1991-06-11 Process, mould and device for low-pressure multi-stage casting of metal Expired - Lifetime EP0463911B1 (en)

Applications Claiming Priority (2)

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FR9007860 1990-06-22
FR9007860A FR2663570B1 (en) 1990-06-22 1990-06-22 PROCESS, MOLD AND PLANT FOR LOW-PRESSURE MULTI-STAGE METAL CASTING.

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EP0463911A1 true EP0463911A1 (en) 1992-01-02
EP0463911B1 EP0463911B1 (en) 1995-03-22

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8304525B2 (en) 2005-03-15 2012-11-06 Universiti Malaya Glycolipids of branched chain alkyl oligosaccharides for liquid crystal and related applications
CN109317620A (en) * 2018-11-30 2019-02-12 马鞍山市华威冶金机械有限公司 A kind of mold and its casting method of batch casting Bitruder barrel liner

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Publication number Priority date Publication date Assignee Title
JP6350050B2 (en) * 2014-07-10 2018-07-04 大同特殊鋼株式会社 Vacuum suction casting method
CN108080588B (en) * 2018-01-22 2021-03-16 铜陵求精机械有限公司 Slag casting die of slag casting machine
RU207520U1 (en) * 2021-07-08 2021-11-01 Акционерное общество «Научно-производственная корпорация «Уралвагонзавод» имени Ф.Э. Дзержинского» DEVICE FOR CONTROLLING LOW PRESSURE METAL INTO A FORM

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3656539A (en) * 1969-01-29 1972-04-18 Amsted Ind Inc Apparatus for casting molten metal
FR2295808A1 (en) * 1974-12-24 1976-07-23 Pont A Mousson LOW PRESSURE CASTING PROCESS AND PLANT IN SAND MOLD
US4112997A (en) * 1977-02-28 1978-09-12 Hitchiner Manufacturing Co., Inc. Metal casting

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3656539A (en) * 1969-01-29 1972-04-18 Amsted Ind Inc Apparatus for casting molten metal
FR2295808A1 (en) * 1974-12-24 1976-07-23 Pont A Mousson LOW PRESSURE CASTING PROCESS AND PLANT IN SAND MOLD
US4112997A (en) * 1977-02-28 1978-09-12 Hitchiner Manufacturing Co., Inc. Metal casting

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8304525B2 (en) 2005-03-15 2012-11-06 Universiti Malaya Glycolipids of branched chain alkyl oligosaccharides for liquid crystal and related applications
CN109317620A (en) * 2018-11-30 2019-02-12 马鞍山市华威冶金机械有限公司 A kind of mold and its casting method of batch casting Bitruder barrel liner

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BR9102619A (en) 1992-01-21
MX173409B (en) 1994-03-01
ES2071941T3 (en) 1995-07-01
NO912403D0 (en) 1991-06-20
PL290755A1 (en) 1992-02-24
HU206845B (en) 1993-01-28
RU2046034C1 (en) 1995-10-20
EP0463911B1 (en) 1995-03-22
HUT59045A (en) 1992-04-28
FI913009A (en) 1991-12-23
DE69108306D1 (en) 1995-04-27
JPH07112593B2 (en) 1995-12-06
NO178367B (en) 1995-12-04
CS188191A3 (en) 1992-06-17
NO178367C (en) 1996-03-13
FI913009A0 (en) 1991-06-19
PL168033B1 (en) 1995-12-30
JPH04231143A (en) 1992-08-20
ATE120113T1 (en) 1995-04-15
FR2663570A1 (en) 1991-12-27
DK0463911T3 (en) 1995-08-14
CA2044879C (en) 1996-02-06
NO912403L (en) 1991-12-23
FR2663570B1 (en) 1992-09-18
HU912080D0 (en) 1991-12-30
FI96097C (en) 1996-05-10
DE69108306T2 (en) 1995-08-03
FI96097B (en) 1996-01-31

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