MXPA06005981A - Casting of metal artefacts - Google Patents

Abstract

The invention provides a process and apparatus (50) for casting an artefact by forming a molten charge of metal, charging a mould with the charge to fill it sufficiently to form a single artefact, the charge solidifying in the mould. The size of the charge is selected to match the capacity of the mould so that charging the mould consumes substantially the whole charge. The apparatus (50) has a container (12) in which a molten charge of metal is held and a mould (54) into which the charge is transferred. The container and mould have matched capacities so that filling the mould with sufficient metal to form a single artefact consumes substantially the whole charge and leaves the container empty.

Description

MOLDING METAL ARTIFACTS Description of the Invention The present invention is concerned with the molding of a metal artifact. More particularly, the invention is concerned with a process for molding a metal appliance and with a molding apparatus or installation for molding a metal appliance, the process and apparatus or installation are particularly suitable for molding light metal artifacts. As used herein, the term "light metal" encompasses both light metals such as and alloys thereof in which light metals form the greater proportion of more than 50% by mass thereof, light metals are those having a density of less than 2.7 grams / cm3. Light metals usually have low melting points of 630 ° C or lower. According to a first aspect of the invention, a process for molding a metal device is provided by forming a molten metal charge from a metal precursor thereof, charging a matrix or mold with the molten charge to fill the matrix or mold sufficiently to form a single metal artefact and cause or allow the charge to solidify in the matrix or mold to form the artifact, the process includes the step of selecting the size of the molten charge to make the matrix or mold of such that the charge of the die or mold consumes substantially all the molten charge, the charge of the die or mold is from a hollow cylinder or sleeve by means of a telescopic piston arrangement that elevates the cylinder or sleeve in coupling with the die or mold and in communication with the loading orifice of the die or mold and a central piston of the piston arrangement that enters the cylinder or sleeve and slides up therein in ac sealing sealed therewith during loading, while a peripheral piston of the piston arrangement, which surrounds the central piston, urges the cylinder or sleeve upward toward a sealing engagement with the die or mold around the loading orifice of the piston. matrix or mold. Although the process may include the step of forming the molten filler from a precursor thereof, which is a mixture of one or more minerals, alkaline fluxes, alloying elements and the like, the molten filler is preferably formed from of the precursor thereof which is a metal slab or ingot or a compact of metal particles, such as burrs or granules or the like. Thus, the process may include the step of pre-forming a metal slab or ingot or pre-forming a compact of particles such as burrs or metal granules. The process may include heating the metal of the molten charge, after forming the molten charge, to raise the temperature of the molten charge, before filling the matrix or mold with the molten charge at the elevated temperature. The step of filling the die or mold with the molten charge can be at a predetermined speed. Preferably, the filling of the matrix or mold with the molten charge is under pressure, for example by injection molding. Particularly and preferably, the filling of the die or mold with the molten charge is under an intermediate pressure, which is neither what is known in the art as low pressure injection molding nor what is known in the art as molding by injection at high pressure. More particularly, charging can be effected by injection molding at an intermediate pressure in the range of 50Kpa-30 MPa. It will be appreciated that routine experimentation can be employed to determine a desired or optimum intermediate pressure under which the die or mold must be filled with the molten charge. The process may include the step of purging the environment in which the molten charge is formed with a purge gas, prior to the formation of the molten charge. Instead of this or in addition, the purge can be effected during the formation of the molten charge. Preferably, the purge is carried out both before and during the formation of the molten charge. The purge gas can be a passive or inert purge gas or can be a noble gas selected from the group consisting of argon, helium, neon and mixtures thereof. Instead of this, the purge gas can be an active purge gas and can be selected from the group consisting of SF6, C02 and mixtures thereof. In particular, the process may include the step of purging the environment in which the molten charge is formed with an active purge gas selected from the group consisting of SF6, C02 and SF6 / CO2 and mixtures thereof, preferably SF6 mixtures. / C02 comprising 0.1 - 0.3% by volume of SFe, before and during the formation of the molten charge. In addition, the process may include, at the beginning of the molten charge formation, the step of sealing the molten charge in place by passing a passive or inert gas selected from the group consisting of argon, helium, neon and mixtures of the and, preferably, argon, beyond the molten charge and in contact therewith, to provide a solidified light metal seal formed from parts of the molten charge. The process may include using as metal, a metal selected from the group consisting of aluminum, magnesium, lithium, zinc and alloys thereof. Preferably, the process includes using the metal as a light metal selected from the group consisting of magnesium, aluminum and alloys thereof. Alloys of light metals means alloys, as indicated above, in which one or more of the light metals form the greater proportion of more than 50% of the mass thereof. The process is expected to be useful in particular in the molding of light metal products or light metal alloy products selected from the group consisting of rim wheels, such as aluminum wheels or magnesium-aluminum alloy wheels, boxes of automotive gears, housings of steering wheels, auxiliary parts or components of the veil and parts or components of automotive engines, marine or aircraft parts or components. Commonly, the process will be used in the molding of aluminum and magnesium alloy wheels in such a way that the molding can be of a light metal artifact in the form of a motorized vehicle wheel. The process is expected to be useful in the molding of artifacts having cross-sectional thicknesses in the range of 1.5-30 mm, usually 2-27 mm, with respective masses of 0.25-30 kg, usually 0.5-20 kg. Thus, in particular, the molding can be of a metal artifact in which the part of the solidified artifact that is furthest from the surface of the artifact is spaced from the nearest part of the artifact surface by a spacing of 0.65 - 15. mm, the artifact has a mass of 0.215 - 30 kg. The process can be used with any type of matrix with mold, for example a matrix or disposable mold such as a matrix or sand mold or a reusable matrix or mold such as a matrix or metal mold. In particular, the process according to the present invention is particularly suitable for use with a metal matrix or mold that forms a reusable matrix or mold. Preferably, the metal die or mold is a steel die or mold. The process can include forming the molten charge by inductive heating of the precursor, the induction heating is in such a way to provide the molten charge with a temperature profile, for example to ensure that the part of the molten charge that enters the matrix or mold is hotter than that to the die or mold later. However, it is possible in principle to obtain any desired profile. According to another aspect of the invention there is provided a molding apparatus or installation for molding a metal device in a die or mold, the molding apparatus or installation includes a die or mold and a melting apparatus that includes a container for containing a precursor to a molten metal charge, a heating arrangement for heating the precursor in the container to form a molten metal charge and a molten metal transfer assembly for transferring a molten metal charge from the container to the matrix or mold, the container and matrix or mold have capabilities which are caused to correspond, in such a way that the loading of the matrix or mold of the container to fill the matrix or mold with a sufficient load to form a single metal device consumes substantially all the molten metal charges of the container and leaves the container empty , the container is a cylinder with hollow sleeve, the molten metal transfer assembly is, a telescopic piston arrangement for raising the cylinder or sleeve in engagement with the die or mold and in communication with the loading orifice to the die or mold and the piston arrangement has a central piston to enter the cylinder or sleeve and to slide up therein in sealed coupling or with it, the piston arrangement has a peripheral piston that surrounds the central piston to drive the cylinder or sleeve upward in sealing engagement with the die or mold around the loading orifice of the o-mold matrix. The heating arrangement can be mounted "on the molten metal transfer assembly.The fusion apparatus can be movable alternately in relation to the die or mold between a loading position, where the melting apparatus charge and a melting apparatus take place. Fusion melting apparatus wherein the transfer of a molten charge from the melting apparatus to the die or mold takes place The apparatus or installation may include a supply of inert gas to supply inert gas to the container, to allow the formation of the molten charge takes place under an inert atmosphere.The container may have a hollow cylindrical interior, for example by being in the form of a hollow cylinder or sleeve.The container may be reusable.Instead of this and preferably, the container is disposable, being for a single use and being discarded later.In the case where the container is disposable, it will be appreciated that the cross contamination is reduced One alloy metal or alloy charge to another, particularly in cases where the apparatus or installation is used successively to mold artifacts comprising different metals or alloys. More particularly, the transfer assembly may comprise a telescopic multi-stage piston arrangement for use in raising the container to be fixedly coupled with a die or mold prior to filling the die or mold with a molten charge from the container. In a particular embodiment of the invention, in which the transfer assembly comprises the telescopic multi-stage piston arrangement, the container is the hollow cylinder, the cylinder is supported on the transfer assembly with its hollow interior in a further position or less vertical, such that a central piston of the multi-stage arrangement is movable upwardly inside the cylinder in sliding engagement and more or less sealed therewith to allow a molten charge in the cylinder to be pushed up and outside the cylinder after the upward movement of the central piston, to transfer the molten charge to a die or mold, a peripheral piston, which surrounds the central piston, is movable upward to drive the cylinder upwards to cause its upper end seated sealingly against a lower surface of the die or mold, around a loading orifice in the matrix or mold. In particular, the central piston can stop a piston head provided with a sealing surface for sealingly engaging the periphery of the loading orifice of the die or mold, preferably when all of the charge in the fluid has been transferred from the cylinder to the cylinder. the matrix or mold. A) Yes, in use, the step of causing or allowing the molten charge to solidify in the die or mold to form the artifact will commonly take place while the piston head is sealingly engaged with the periphery of the orifice. The molding apparatus or installation can be essentially immobile construction, being built in situ, in a production facility for molding light metal artifacts, in which case it can be considered as an installation. Instead of this and usually, the molding apparatus or installation is expected not to be of immobile construction, being movable from one production facility to another, in which case it can be considered as an apparatus. The fusion apparatus may be provided with wheels for running on rails that are part of the molding apparatus or installation, the wheels are for allowing reciprocating movement of the fusion apparatus between the loading position where the container load with a precursor a molten charge in use takes place and a filling position wherein the fusing apparatus is in alignment with the loading orifice to the die or mold, to allow the container to be brought upwardly into a sealing contact with the die or mold and in communication therewith and allow a molten charge formed by the melting of the precursor in the container to be transformed from the container to the matrix or mold, thereby filling the matrix or mold with the molten charge. It will be appreciated that, whether or not the container and matrix or mold have matching capabilities as defined and described above, the invention contemplates a molding apparatus or installation for molding a metal device in a die or mold, the apparatus or Molding installation includes, in combination, a die or mold and a melting apparatus including a container for containing a precursor of a molten metal charge, a heating arrangement for heating the precursor in the container to form a molten metal charge. and a molten metal transfer assembly for transferring a molten metal charge from the container to the die or mold, the heating arrangement is mounted on the metal transfer assembly.

An important subset of this combination is a melting apparatus that includes a container for containing a precursor of a molten metal charge, a heating arrangement for heating the precursor in the container to form a molten metal charge, and a transfer set for Molten metal for transferring the molten charge from a container to a die or mold, the container and the heating arrangement are both mounted on the molten metal transfer assembly. Similarly, it will be appreciated that if the container and die or mold have or do not have capabilities which are matched as described above, the invention contemplates a molding apparatus or facility for molding a metal artefact in a die or mold, the apparatus or Molding installation includes, in combination, a die or mold and a melting apparatus including a container for containing a precursor of a molten metal charge, a heating arrangement for heating the precursor in the container to form a molten metal charge. and a molten metal transfer assembly for transferring a molten metal charge from the container to the matrix or mold, the fusion apparatus is movable alternately between the matrix or mold between a loading position where the charge of the fusion apparatus takes place and a filling position wherein the charge of a transfer of a molten charge from the melting apparatus to the die or mold takes place. In turn, an important subset of this combination is a container for containing a precursor of a molten metal charge, a heating arrangement for heating the precursor in the container to form a molten metal charge and a molten metal transfer assembly. to transfer the molten charge from a container to a die or mold, the fusion apparatus is movable alternately between a loading position where the charge of the melting apparatus takes place and a filling position wherein the transfer of a molten charge from the Fusing apparatus to a matrix or mold take place. It will be emphasized, as indicated above, that it is an important aspect of the present invention that the capacity of the container is not greater than and is at least approximately corresponding to the size of a molten charge required to fill the matrix or mold to produce a single artifact. This means that, each time the die or mold is loaded with a molten charge of the fusion apparatus sufficient to form a single artifact, the container of the fusion apparatus or facility will be emptied. The array or mold arrangement may comprise a reusable die or mold. In particular, the reusable die or mold can be a metal die or mold, preferably a steel die or mold. In particular, the matrix or mold can be a multi-core segmented matrix or mold. The matrix or mold arrangement may include a heating arrangement for heating the matrix or mold arrangement to a molding temperature. The heating arrangement may be an induction heating arrangement comprising one or more heating coils. In each case, wherein the melting apparatus, on the one hand, and the array or die arrangement, on the other hand, include one or more induction heating coils, the heating coils can be electrically connected to a power supply for them. In particular, the die or mold can be provided with a heating arrangement that includes a plurality of at least two induction coils, which are independently operable to provide the interior surface of the die or mold with a temperature profile. The invention makes possible the provision of a molding installation, which includes two or more molding apparatus or installations, the installation includes two or more fusion apparatus as defined above for melting metal charges, the molding facility also includes the same number of matrix arrangements or molds from which the molding of the artifacts is carried out, the fusion appliances share a power source of the common heating and the matrix or mold arrangements share a common heating power source, for molding artifacts in respective molding cycles that are commonly sufficiently out of phase to allow such a compartment, while allowing the use of common heating power supplies that are not larger, if there are, that necessarily for the use of the fusion apparatus or a single apparatus or molding installation. The arrangement of the installation is particularly appropriate for the case where each heating arrangement is an induction heating arrangement, the heating energy supplies are sources of electrical power. During the use of a molding interaction as defined above, the process of the present invention may include using one of the power supplies shared in succession to form molten charges in the respective vessels of the fusion apparatus and using the other sources. of feed shared successively to heat the respective matrix or mold arrangements, in molding cycles that are out of phase. • The invention will now be described by way of non-limiting illustrative example with reference to the attached schematic figures in which: Figure 1 shows a detailed schematic side elevational view of the various components of a fusion apparatus according to the invention, to form a molten charge of light metal, according to the process of the invention; Figure 2 is a three-dimensional view of a molding apparatus or installation according to the invention, for molding light metal artifacts, according to the method of the invention; Figure 3 is a three-dimensional view of a molding installation comprising two molding apparatus or installations of Figure 2, according to the invention, for molding light metal artifacts according to the method of the invention; Figure 4 shows a series of simplified schematic side elevation views of the molding apparatus or interaction of Figure 2, illustrating the method for molding a light metal artifact in the form of a magnesium alloy wheel according to the invention. invention, using the molding apparatus or installation of Figure 2 and Figure 5 is another series of simplified schematic side elevation views of the molding apparatus or installation of Figure 2, which further illustrate the method for molding a light metal device in the form of a magnesium alloy rim wheel illustrated by Figure 4. Referring first to Figure 1 of the Figures, reference numeral 10 generally refers to a melting apparatus for forming a molten charge of light metal, according to the invention. The melting apparatus 10 comprises a container 12 in the form of a hollow cylinder or sleeve 14 of circular cross-section to contain a molten charge of light metal and also to facilitate the heating of a precursor of the light metal charges, a heating arrangement by induction 16 comprising an induction coil 18 for heating the contents of the cylinder or sleeve 14 to form a molten charge and a molten metal transfer assembly 20 for transferring a molten charge of light metal from the cylinder or sleeve 14 to a matrix or mold (not shown in Figure 1, but seen in Figures 3 to 5) in which an artifact is molded. The melting apparatus 10 includes a supply of inert gas 22 for supplying argon gas to the interior of the sleeve or cylinder 14, such that the melting of the light metal charge takes place under a substantially inert atmosphere and also to provide extreme cooling. bottom or base of the cylinder or sleeve 14 to form a secondary seal therefor as hereinafter described. The cylinder or sleeve 14 is reusable. The cylinder or sleeve 14 is made of steel of low carbon content or moderate carbon content. In other embodiments, the cylinder or sleeve 14 is optionally made of cast iron or stainless steel. In service, the induction coil 18 is mounted on the metal transfer assembly 20, the coil 18 is connected to the barrel 32 and surrounds the cylinder or sleeve 14 to heat the contents thereof. The transfer assembly 20 comprises a telescopically movable multi-stage piston arrangement 24 for use in raising the cylinder or sleeve 14 to fixedly engage with the periphery d a loading port facing downwardly of a die or mold, prior to filling the die or mold with a molten charge of the cylinder or sleeve 14. the multi-stage piston arrangement 24 incorporates a central piston comprising three telescopic piston rods 26, 27, 28, the central rod 28 having a piston head 30 provided with a conical sealing surface 31 for sealingly engaging the periphery of an orifice to a die or mold when a whole molten charge between the cylinder or sleeve 14 has been transferred from the cylinder or sleeve 14 to the die or mold. The multi-stage piston arrangement 24 includes a variable speed and force controller (not shown) for controlling the speed of movement thereof and also for controlling the upward force exerted by the piston head 30 on a molten charge in the cylinder. or sleeve 14 and in a matrix or mold, when the piston head 30 is sealingly coupled with the periphery of the loading orifice of the die or mold. Thus, in use, the cylinder or sleeve 14 is supported with the transfer assembly 20, such that the multi-stage piston arrangement 24 is movable within the interior of the cylinder or sleeve 14 in sliding engagement and sufficient sealing with the same to allow a molten charge in the cylinder or sleeve 14 to be pushed up or out of the cylinder or sleeve 14 after the upward movement of the piston rods 26, 27, 28, to transfer and inject the molten charge to a matrix or mold. The transfer assembly 20 also comprises a plurality of concentric barrels 32, 34, 35, 36 and 37 of different diameters. The barrels 32, 34, 35, 36 and 37 are vertically movable telescopically to each other and interconnected. The barrel 32 is the bottom barrel and has wheels 38 for running on rails 39 which form part of the molding installation of Figures 3 to 5 to alternately move the fusion apparatus 10 between a loading position where the load of the cylinder or sleeve 14 with a precursor of a molten charge takes place and a filling position wherein the melting apparatus 10 is in alloy with the loading orifice of a die or mold of a molding apparatus or facility, to allow a Molten charge formed by the melting of a precursor thereof in the cylinder or sleeve 14 is transferred therefrom to the die or mold, filling it by this commonly with the molten charge. The barrel 37 is the upper barrel and provides a circumferentially extending upward facing support ring having a slit (not shown) for sealingly engaging the lower end of the cylinder or sleeve 14 therein. The barrel 35 in turn provides a circumferentially extending upward facing support ring on which the induction coil 18 is supported when placed on the cylinder or sleeve 14 to encircle it. In addition to the seal provided by the slit on the barrel 37, argon gas supplied via the gas supply 22 provides insulation to the lower end of the cylinder or sleeve 14 at the beginning of the molten charge precursor position, allowing part of the load The formed melt solidifies an area between the piston arrangement 24 and the upper barrel 37 and at the lower end of the cylinder or sleeve 14, thereby providing a secondary seal which is formed of solidified light metal from the molten charge. Referring now to Figure 2 of the Figures, the reference number 50 generally refers to a molding apparatus or installation for molding light metal artifacts, in accordance with the invention. The same reference numbers are assigned to the same parts as in Figure 1, unless otherwise specified. The molding apparatus or installation 50 comprises the melting apparatus 10 as described above and a matrix or mold arrangement 52 comprising a die or mold 54 and a heating arrangement 56. The die or mold 54 is a matrix or mold of multi-core or segmented reusable steel comprising an upper core 58 to which the solidified device remains removably attached at the end of the molding process, a bottom or face core 60 having a centrally located load orifice 62 provided through it to load or fill the die or mold 54 from below and a segmented ring of four side cores 64 associated with respective pistons 66, the side cores 64 give the die or mold 54 its segmented character. The die or mold 54 is put into operation hydraulically, with respect to the pistons 66 of the side cores 64 and with respect to the lifting of the core 552, 58 and any molding of light metal attached (not shown) up and away from the remaining cores. The molding apparatus or installation includes a hydraulic controller for the die or mold 67 and a hydraulic controller 69 of the melting apparatus or installation 10. The upper core 58 is associated with release means (not shown) for releasing the artifact therefrom. at the end of the molding process. The heating arrangement 56 comprises six induction windings which respectively form induction coils, operable independently from each other, to obtain a desired temperature profile in the die or mold 54. Thus, the molding apparatus or installation 50 also includes a central processing unit (CPU) 70 to verify heating of the heating arrangement 56 for having the desired temperature profile and also to provide feedback control to respective power supplies 82 and 84 (Figure 3) therefor. The molding apparatus or installation 50 also includes rails (not shown) on which the wheels 38 of the metal transfer assembly 20 that are part of the fusion apparatus or facility 10 can run. Thus, the melting apparatus 10 is movable alternately in relation to the array array 52 between a loading position (as shown in Figure 2) wherein the charge of the melting apparatus 10 with a precursor of the molten charge takes place and a filling position (see Figures 4 and 5) wherein the transfer of a molten charge from the melting apparatus 10 to the matrix 54 of the mold array 52 takes place.

Referring now to Figure 3 of the Figures, the reference numeral 80 generally refers to a molding installation according to the invention. The molding installation 80 comprises two molding apparatus or installations 50 each comprising a fusion apparatus 10 for the induction melting of a light metal charge and a matrix or mold arrangement 52 in which it is carried out in the molding of the artifact. The molding installation 80 also includes a fusing induction heating power supply 82, for example 100 kilowatts, to separately supply energy to each of the two fusion apparatuses 10, an induction heating power supply of the matrix 80, also for example 100 kilowatts, for separately supplying power to matrix or mold arrays 52, a cooling tower (not shown) to provide the cooling fluid and a gas supply control unit 58 for supplying gases of purge to the fusion apparatus 10 and also to the matrix or mold arrangements 52. It will be appreciated that the molding installation 80 allows two artifacts to be molded simultaneously using molding cycles that are off base, the fusion apparatus 10 share the common induction heating power supply 82 and the matrix or mold arrangements 52 share the source of the heating induction by common induction 841. The molding of the artifacts then takes place in respective molding cycles that are sufficiently out of phase to allow such sharing. It will thus be appreciated that the molding installation 80 can be placed in the frame in an almost continuous manner, in which the molding apparatus or installations 50 can be used in an alternating base, one has its fusion apparatus 10 in its filling position and is used for molding while the other has its fusion apparatus or installation in its loading position and is loaded with a light metal precursor and is ready to be moved alternately to its filling position, as soon as the process of molding in the other molding apparatus or installation 50 is accomplished. Referring now to Figures 4 and 5 of the Figures, the use of the molding apparatus or interaction 50 described above is illustrated with reference to the molding of a light metal artifact in the form of a rim wheel. magnesium alloy 90, using a precursor in the form of a preformed slab or ingot 92 of a magnesium-aluminum-zinc alloy known in the art as AZ91. The yew or ingot 92 is placed on the piston arrangement 24, with the associated fusion apparatus 10 in its loading position. The cylinder or sleeve 14 is placed on the shingle or ingot 92, such that the lower end of the cylinder or sleeve 14 is sealingly engaged with the slit on the upper barrel 37 of the metal transfer assembly 20.

The induction coil 18 is connected to the barrel 35 of the metal transfer assembly 20, in such a way that the positioning of the cylinder or sleeve 14 and the shingle or ingot 92 in position acts to have them surrounded by the coil 18. The array arrangement 52 is prepared for molding by folding down the upper core 58 in such a way that it engages with the bottom or face core 60. Then the segments of the ring side core 64 are placed in position, using their pistons 66, to close the matrix . The purge gas in the form of an SFe / C02 aine flux gas mixture comprising 0.2% by volume of SFβ is fed to the matrix or mold 54 and the matrix or mold 54 is heated using the induction coil 64 by energy electric powered from the induction heating power supply 84 using a preselected frequency until the die or mold 54 obtains a required operating temperature and has a desired temperature profile. The heating rate can be altered by changing the power input of the power source 84 and / or by changing the frequency of the same., a higher frequency results in a higher heating rate and the turns or loops of coils 64 can be selectively operated with different supply bridges thereto, to obtain the temperature profile. The melting apparatus 10 is alternatively moved with the help of the wheels 38 on the rails (not shown) in the molding apparatus or installation 50, from the loading position where the loading of the cylinder or sleeve 14 with the yew or the ingot 92 of an AZ91 alloy precursor charge takes place, at a filling position where the melting apparatus or installation 10 is in alignment with the loading orifice 62 through the bottom or loading core 60 of the die or mold 54. The cylinder or sleeve 14 is sealingly coupled with the lower surface of the bottom or face core 60, by raising the barrel 37 hydraulically, which also seals the cylinder or sleeve 14 to the barrel 37. the cylinder or sleeve 14 is purged by a purge atmosphere of SF6 / C02. The yew or ingot 92 is sunk under the purge atmosphere introduced to the sleeve cylinder 14 by the gas supply 22, until a molten charge of AZ91 alloy is formed. Argon is then used to provide a cooling atmosphere for the cooling of the molten charge at the lower end of the sleeve cylinder 14 to form a secondary seal in the form of a more or less semi-solid portion or hold or solidified portion of the light metal (not shown). Once the desired operating temperature and temperature profile have been obtained in the die or mold 54 and the die or mold 54 has been locked under pressure with the help of the pistons 66 by means of the hydraulic controller 67, the gas supply the cylinder or sleeve 14 is cut off and the molten charge is transferred under pressure from the cylinder or sleeve 14 to the die or mold 54 by means of the piston arrangement, thereby filling the mold die 54 with the cast face. Before and during the injection of the molten face into the die or mold 54, the die or mold 54 is purged with the aforementioned SF6 / C02 alkaline bleed / flux gas by means of the gas supply control unit 86, such The gas also protects the molten surface from the molten face in both the sleeve 14 and when it enters the die or mold 54. The piston head 30 is sealingly locked against the periphery of the loading orifice 62 and partially enters the orifice. load 62 to increase the pressure on the molten charge of the die or mold 54. The die or mold 54 is allowed to cool and the melting apparatus or facility 10 is separated from the die or mold 54. Then the apparatus or installation Fusion 10 is alternately moved back to its loading position. Then, the die or mold 54 is opened by hydraulically separating the ring of side segments and core 64 from each other with the help of the pistons 66 and the upper core 58 with the solidified wheel 90 appended thereto, is lifted, using the controller 67 Then the wheel 90 is separated or released from the upper core 58 by allowing bolts directed below that form part of the release means (not shown) to push the wheel 90 downwards during the lifting of the upper core 58. The piston arrangement 24 is lowered and then the barrels of the assembly 20 are retracted, releasing the cylinder or sleeve 14 and the solidified portion or spreader (not shown) of the molten charge that formed the secondary seal for the cylinder or sleeve 14. Then the cylinder or sleeve used 14 is • discarded and a new cylinder or sleeve 14 is used for the molding of a new wheel 90. It will be appreciated that the waste of the used sleeve or cylinder 14 and the use of a new cylinder or sleeve 14 for molding a new wheel 90, allows the substantially uninterrupted molding of artifacts one after the other of shingles or ingots comprising different alloy compositions, taking only the molding of the same alloy composition, using the same molding cycle but naturally with different temperatures and temperature profiles if appropriate. In one embodiment of the invention, the melting apparatus or installation 10 allows the molding of alloy wheels comprising the following alloys one after the other, without fear of cross contamination: AM60B (aluminum-magnesium-manganese alloy), Galsi 12dv (aluminum-silicon alloy), AZ91 (magnesium-aluminum-manganese-zinc alloy) and Galsi7 (aluminum-silicone alloy). It is an advantage of the present invention that the size of the precursor for the fluid charge, for example the olingote 92, is matched to the volume of the molten metal charge required to load or fill the matrix or mold 54 to produce a single artifact, for example a single wheel 90. Thus, the waste of metal is reduced, if not eliminated, compared to the molding of light metal artifacts or wheels 90 according to the molding processes generally known by the art. , wherein substantially more light metal is melted than is required for a wheel. It is a further advantage of the invention that the fusion apparatus 10 and also the molding apparatus or installation 50 are not necessarily expected to be of a permanent construction, being movable from one production facility to another with ease, thus, the apparatus or molding facility 50 can be adjusted non-face-to-face closer to the end user of the artifacts to be molded, thereby reducing transportation costs and the like. It is a further advantage of the present invention that the molding apparatus or installation 50 does not require much space to be erected. For example, the molding apparatus or installation 50 as described above requires only a floor space of approximately 23 m2. The present process also offers other cost benefits such as the fact that the power source only has to be fed to the molding apparatus or facility 50 immediately before molding and can be turned off at the end of the molding of a single device, without affecting adversely affect the process or its efficiencies. In the case of a power interruption during the molding process using the molding or installation method and apparatus 50 of the present invention, it will be appreciated that the losses will not need to be greater than the loss of a molten charge in the cylinder or sleeve, which comprises the single yew or ingot 92, as compared to a typical foundry where the process is continuous and large quantities of metal have to be melted at any point in the given time, all of which may solidify in the case of an interruption of Energy. Certainly, the losses can in principle be completely avoided, by simply recasting the contents of the cylinder or sleeve 14 when the power source is restored. It is an additional advantage of the process according to the present invention that it does not require shifting in order to obtain optimal process conditions. Light metal precursors such as the yew or ingot 92 are fabricated to a required composition and metallography. Thus, precursors such as the yew or ingot 92 can be an inventory item. It will be appreciated that wheels 90 produced from an inventory of yews or ingots 92 will exhibit similar metallography and hence similar properties, so that quality control is improved. The fact that the process does not require a cycle or run cycles means that a particular number of yews or ingots 92, avoiding any power interruptions, must produce an equivalent number of wheels 90.

Claims (16)

1. CLAIMS 1. A process for molding a metal device by forming a molten metal charge from a metal precursor, loading a matrix or mold with the molten charge to fill the matrix or mold sufficiently to form a single artifact. of metal and causing or allowing the charge to solidify the matrix or mold to form the artifact, includes the step of selecting the size of the molten charge to match or match the capacity of the matrix or mold in such a way that the load of the matrix or mold consumes substantially all the molten charge, the process is characterized because, in combination: the load of the matrix or mold is a hollow cylinder or sleeve by means of a telescopic piston arrangement that raises the cylinder or sleeve in coupling with the die or mold and in communication with a loading orifice to the die or mold and a central piston of the piston arrangement enters the cylinder or sleeve and slides up into the in the sealing coupling with the same before the load, while a peripheral piston of the piston arrangement, which surrounds the central piston, drives the cylinder or sleeve upwards in sealing engagement with the mold or matrix around the orifice of the piston. load of the matrix or mold.
2. 2. The process according to claim 1, characterized in that the formation of the molten charge is a precursor thereof which is a metal slab or ingot or a compact of metal particles.
3. 3. The process according to claim 1 or 2, characterized in that it includes heating the metal of the molten charge, after the formation of the molten charge, to raise the temperature of the molten charge, before filling the matrix or mold. with the melted charge at the elevated temperature.
4. 4. The process according to any of claims 1-3, characterized in that the charging is carried out by injection molding at an intermediate pressure in the range of 50 Kpa-30 mPa.
5. The process according to any of the preceding claims, characterized in that it includes the step of purging the environment in which the molten charge is formed with a purge gas, before and during the formation of the molten charge.
6. The process according to any of the preceding claims, characterized in that it includes, as the metal, a metal selected from the group consisting of aluminum, magnesium, lithium, zinc and alloys thereof.
7. The process according to claim 6, characterized in that it includes, as the metal, a light metal selected from the group consisting of magnesium, aluminum and alloys thereof.
8. 8. The process according to claim 7, characterized in that the molding is of a light metal device in the form of a wheel of a motorized vehicle.
9. 9. The process according to any of the preceding claims, characterized in that the molding is a metal artifact in which part of the solidified artifact that is farthest from the surface of the artifact is spaced from the nearest part of the surface of the artifact. artifact for a space of 0.75 - 15mm, the artifact has a mass of 0.25 - 30 kg.
10. 10. A molding apparatus or installation for molding a metal artefact in a die or mold, the molding apparatus or installation includes a die or mold and a melting apparatus that includes a container for containing a precursor of a molten metal charge. , a heating arrangement for heating the precursor in the container to form a molten metal charge and a molten metal transfer assembly for transferring a molten metal charge from the container to the matrix or mold, the container and the matrix or mold have capabilities such that they are matched to be of equal volume such that charging the die or mold of the container to fill the die or mold with a load sufficient to fill a single metal device consumes substantially all of the metal charge melt the container and leave the container empty, the apparatus or installation is characterized in that, in combination: the container is a hollow cylinder or sleeve, the molten metal transfer assembly is a telescopic piston arrangement for raising the cylinder or sleeve in engagement with the die or mold and in communication with a loading hole in the die or mold and the piston arrangement has a central piston to enter the cylinder or sleeve and to slide up therein in sealing engagement with it, the piston arrangement has a peripheral piston that surrounds the central piston to urge the cylinder or sleeve upward in sealing engagement with the die or mold around the loading orifice of the die or mold.
11. The apparatus or installation according to claim 10, characterized in that the heating arrangement is mounted on the molten metal transfer assembly.
12. 12. The apparatus or installation according to claim 10 or 11, characterized in that the fusion apparatus is movable alternately in relation to the die or mold between a loading position wherein the charge of the fusion apparatus takes place and a position of filling wherein the transfer of a molten charge from the melting apparatus to the die or mold takes place.
13. The apparatus or installation according to any of claims 10-12, characterized in that it includes a supply of inert gas to supply inert gas to the container, to allow the formation of the molten charge to take place under an inert atmosphere.
14. The apparatus or installation according to any of the inclusive claims 10-13, characterized in that the container has a hollow cylindrical interior.
15. 15. The apparatus or installation according to claim 10, characterized in that the central piston has a piston head provided with a sealing surface for sealingly engaging the periphery of the loading orifice of the die or mold. The apparatus or installation according to any of claims 10-15 inclusive, characterized in that the heating arrangement includes at least one induction coil surrounding the container