Method for casting a melt of a metal material, and casting device designed for carrying out the method

Abstract

The invention relates to a method and a device for casting a melt 4 of a metallic material by means of a furnace 2 of a low pressure casting device, which furnace 2 has a receiving space 3 and a riser tube protruding into said receiving space 3. By pressurizing the receiving space 3 with compressed air, the melt 4 in the riser tube 12 of the furnace 2 is pressed into a mold cavity 10 of a mold 7, wherein simultaneously, a magnetic field acting against the conveying direction 23 of the melt 4 is applied to the melt 4 of the metallic material by means of a magnetic element 16 arranged in the region of the riser tube 12.

Claims

1. A method for casting a melt of a metallic material by a furnace of a low pressure casting device or counter pressure casting device, which has a receiving space, a riser tube protruding into the receiving space, and first and second electrodes arranged in the riser tube on two opposing sides thereof, the first electrode and the second electrode being shorted with one another by a current bridge, the method comprising: pressurizing the receiving space with compressed air, so that the melt in the riser tube of the furnace is pressed into a mold cavity of a mold, wherein simultaneously, a magnetic field acting against a conveying direction of the melt is applied to the melt of the metallic material by a magnetic element arranged in the region of the riser tube.

2. The method according to claim 1, wherein the magnetic field is generated by an electromagnet.

3. The method according to claim 1, wherein the metallic material comprises aluminum or an aluminum alloy.

4. The method according to claim 1, wherein a magnetic force acts upon the melt against the conveying direction in a flow connection element, wherein a current is induced in the melt by movement of the melt in the flow connection element and by the magnetic force acting on the melt, which current causes a magnetic field in the melt.

5. The method according to claim 1, wherein the current bridge is formed of a material which has a higher electric conductivity than the material of the melt.

6. The method according to claim 1, wherein the first electrode and the second electrode in the riser tube are used to measure an induction voltage occurring in the melt and/or an induction current, wherein, based on the measured induction voltage and/or induction current, a flow speed of the melt is calculated.

7. The method according to claim 1, wherein the magnetic field in the magnetic element and/or currents in the first electrode and the second electrode is/are applied in a pulsed manner.

8. The method according to claim 7, wherein at least one capacitor is provided for application, in a pulsed manner, of the magnetic field in the magnetic element and/or of the currents in the first electrode and the second electrode.

9. A casting device for low-pressure or counter-pressure casting of a melt of a metallic material, the casting device comprising: a furnace for receiving the melt, the furnace including: an inlet through which compressed air is introduced into the furnace to pressurize the furnace, and a riser tube for transferring the melt into a mold cavity of a mold; first and second electrodes arranged in the riser tube on two opposing sides thereof, the first and second electrodes being shorted with one another by a current bridge; and a magnetic element arranged in the region of the riser tube to apply a magnetic field to the melt against a conveying direction of the melt.

10. The casting device according to claim 9, wherein the magnetic element is formed as an electromagnet, which has a coil that, at least in some regions, surrounds the riser tube.

11. The casting device according to claim 9, wherein multiple mold cavities are formed in the mold, which mold cavities are each coupled with a runner via a gate, wherein a magnetic element is arranged in one or multiple ones of the gates.

12. The casting device according to claim 9, wherein the riser tube has a rectangular cross-section, and wherein the first electrode and the second electrode are arranged in two opposing sides of the cross-section.

13. The casting device according to claim 9, wherein the furnace has at least two riser tubes for transferring the melt into the mold cavity.

14. The casting device according to claim 9, wherein the furnace further includes a second riser tube for transferring the melt into a second mold cavity of a second mold.

15. The casting device according to claim 9, wherein the current bridge is formed of a material which has a higher electric conductivity than the material of the melt.

16. A method for casting a melt of a metallic material by a furnace of a low pressure casting device or counter pressure casting device, which has a receiving space, a riser tube protruding into the receiving space, and first and second electrodes arranged in the riser tube on two opposing sides thereof, the method comprising: pressurizing the receiving space with compressed air, so that the melt in the riser tube of the furnace is pressed into a mold cavity of a mold, and, simultaneously, utilizing a magnetic element arranged in the region of the riser tube to apply a magnetic field to the melt against a conveying direction of the melt; via the first electrode and the second electrode in the riser tube, measuring an induction voltage occurring in the melt and/or an induction current; and calculating a flow speed of the melt based on the measured induction voltage and/or induction current.

17. A method for casting a melt of a metallic material by a furnace of a low pressure casting device or counter pressure casting device, which has a receiving space, a riser tube protruding into the receiving space, and first and second electrodes arranged in the riser tube on two opposing sides thereof, the method comprising: pressurizing the receiving space with compressed air, so that the melt in the riser tube of the furnace is pressed into a mold cavity of a mold, and, simultaneously, utilizing a magnetic element arranged in the region of the riser tube to apply a magnetic field to the melt against a conveying direction of the melt; and wherein the magnetic field in the magnetic element and/or a current in the first and second electrodes is/are applied in a pulsed manner.

18. A casting device for low-pressure or counter-pressure casting of a melt of a metallic material, the casting device comprising: a furnace for receiving the melt, the furnace including: an inlet through which compressed air is introduced into the furnace to pressurize the furnace, and a riser tube for transferring the melt into a mold cavity of a mold; first and second electrodes arranged in the riser tube on two opposing sides thereof; a magnetic element arranged in the region of the riser tube to apply a magnetic field to the melt against a conveying direction of the melt; and a capacitor coupled to the magnetic element or to the first and second electrodes configured for applying, in a pulsed manner, the magnetic field in the magnetic element and/or a current in the first and second electrodes.

19. The casting device according to claim 18, wherein the magnetic element is formed as an electromagnet including a coil that surrounds at least a portion of the riser tube.

20. The casting device according to claim 18, wherein the riser tube has a rectangular cross-section, and wherein the first electrode and the second electrode are arranged in two opposing sides of the cross-section.

Description

(1) These show in a respectively very simplified schematic representation:

(2) FIG. 1 a first exemplary embodiment of a casting device in the form of a low pressure ingot mold device or counter pressure ingot mold device;

(3) FIG. 2 a further exemplary embodiment of a casting device in the form of a low pressure ingot mold device or counter pressure ingot mold device;

(4) FIG. 3 a first exemplary embodiment of a gravity casting device;

(5) FIG. 4 a further exemplary embodiment of a gravity casting device;

(6) FIG. 5 an exemplary embodiment of a continuous casting device;

(7) FIG. 6 an exemplary embodiment of a casting device with multiple mold cavities;

(8) FIG. 7 a first exemplary embodiment of a cross-section of a flow connection element or gate;

(9) FIG. 8 a second exemplary embodiment of a cross-section of a flow connection element or gate;

(10) FIG. 9 a third exemplary embodiment of a cross-section of a flow connection element or gate;

(11) FIG. 10 a fourth exemplary embodiment of a cross-section of a flow connection element or gate;

(12) FIG. 11 a fifth exemplary embodiment of a cross-section of a flow connection element or gate;

(13) FIG. 12 an exemplary embodiment of electrodes arranged one after the other;

(14) FIG. 13 an exemplary embodiment of circumferential electrodes arranged one after the other;

(15) FIG. 14 a further exemplary embodiment of a casting device in the form of a low pressure ingot mold device or counter pressure ingot mold device.

(16) First of all, it is to be noted that in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclosures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position.

(17) FIG. 1 shows a schematic representation of a first exemplary embodiment of a casting device 1. The casting device 1 in this exemplary embodiment is formed as a low pressure ingot mold casting device or as a counter pressure ingot mold casting device.

(18) The casting device 1 comprises a furnace 2 in which a receiving space 3 for receiving melt 4 is formed. In particular, it can be provided that crucibles 5 are arranged in the furnace 2, in which crucibles 5 the melt 4 is received. The crucible 5 can be formed of a ceramic material, which exhibits a high temperature resistance. The furnace 2 can serve, in particular, for keeping the melt 4 at a high temperature level, so that it remains in a molten state.

(19) Moreover, a platen 6 is formed, which forms an upper delimitation of the furnace 2. The platen 6 can be formed either as a distinct component or as an integral component of the furnace 2. Above the platen 6, a mold 7 is arranged which has a lower mold part 8 and an upper mold part 9. The two mold parts 8, 9 form a mold cavity 10, which serves for receiving the melt 4 and for shaping the cast workpiece.

(20) The mold 7 can, for example, be formed in the form of an ingot mold, which is suitable for casting multiple thousand workpieces.

(21) As an alternative to this, it is also conceivable that the mold 7 is formed as an expendable mold, for example made from a sand material, and therefore serves only for casting a single workpiece.

(22) Moreover, a flow connection element 11 is formed, which serves for directing the melt 4 from the crucible 5 into the mold cavity 10. In the present exemplary embodiment, the flow connection element 11 is formed as a riser tube 12, which protrudes into the receiving space 3 of the furnace 2 and penetrates the platen 6. The lower mold part 8 can directly follow the riser tube 12 and have a gate 13 into which the riser tube 12 opens. Additionally, a very simplified representation shows a supporting structure 14 which can be coupled with the upper mold part 9 and can serve for moving the upper mold part 9 relative to the lower mold part 8.

(23) The furnace 2 further has a compressed air supply opening 15 through which compressed air can be introduced into the receiving space 3 of the furnace 2. By pressurizing the receiving space 3 of the furnace 2 with compressed air, the melt 4 in the riser tube 12 is pressed into the mold cavity 10.

(24) The surface of the electrodes 20, 21 can be integrated into the inner jacket surface 19 of the flow connection element 11 or of the gate 13. Thus, the electrodes 20, 21 can lie flush with the inner jacket surface 19 of the flow connection element 11 or of the gate 13.

(25) In a further embodiment variant, it can also be provided that the electrodes 20, 21 are placed on the inner jacket surface 19 of the flow connection element 11 or of the gate 13. In such an exemplary embodiment, the electrodes 20, 21 protrude inwardly with respect to the inner jacket surface 19 of the flow connection element 11 or of the gate 13.

(26) Moreover, a magnetic element 16 is formed which, in the present exemplary embodiment, is arranged in the region of the flow connection element 11. The magnetic element 16 in the present exemplary embodiment is formed as an electromagnet 17 which has a coil 18. Here, the coil 18 is formed such that the flow cross-section of the flow connection element 11 is enclosed annularly by the coil 18. In particular, it can be provided here, as it can be seen in FIG. 1, that the coil 18 is arranged within the furnace 2 and surrounds the riser tube 12. As an alternative to this, it can also be provided that the coil 18 is integrated into the riser tube 12. Of course, a permanent magnet can also be provided instead of the coil 18.

(27) In the sectional view I-I, it can be seen that, in the region of the magnetic element 16, a first electrode 20 and a second electrode 21 are arranged on an inner jacket surface 19 of the riser tube 12, which electrodes are formed to subject the melt 4 being transported in the riser tube 12 to current. By means of the magnetic element 16, a magnetic force 22 can be exerted onto the magnetic element 4 being led in the flow connection element 11. Here, the magnetic force 22 can act in a conveying direction 23 or also against the conveying direction 23.

(28) In particular, it is conceivable that the magnetic force 22 acts as a conveyance support for conveying the melt 4 from the crucible 5 into the mold cavity 10.

(29) FIG. 2 shows another exemplary embodiment of a low pressure ingot mold casting device and/or counter pressure ingot mold casting device.

(30) FIG. 2 shows a further and possibly independent embodiment of the low pressure ingot mold casting device and/or counter pressure ingot mold casting device, wherein again, equal reference numbers and/or component designations are used for equal parts as before in FIG. 1. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIG. 1 preceding it.

(31) As it can be seen in FIG. 2, it can be provided that the magnetic element 16 is integrated into the platen 6 and surrounds the riser tube 12 in this region.

(32) FIG. 3 shows a further and possibly independent embodiment of the casting device 1, wherein again, equal reference numbers and/or component designations are used for equal parts as before in FIGS. 1 and 2. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIGS. 1 and 2 preceding it.

(33) As it can be seen in FIG. 3, it can be provided that the casting device 1 is formed as a device for gravity casting, wherein, in the present exemplary embodiment, the mold 7 is formed as an expendable mold of sand. Here, the mold cavity 10 is flow-connected with a runner 24 via the gate 13, into which runner 24 a sprue 25 opens. Here, the melt 4 is poured into the sprue 25 by means of the crucible 5, and reaches the mold cavity 10 via the runner 24 and the gate 13. Here, feeders 26 serve for de-aerating the mold cavity 11 and/or as a reservoir during the solidification of the melt.

(34) The magnetic element 16 and/or the electrodes 20, 21 can be integrated directly into the mold 7 in such an exemplary embodiment. It is conceivable, for instance, that the magnetic element 16 and the electrodes 20, 21 are arranged in the region of the runner 24. As it can also be seen in FIG. 3, it can be provided that the magnetic element 16 and the electrodes 20, 21 are arranged in the region of the gate 13.

(35) The arrangement described above of the magnetic element 16 and/or the electrodes 20, 21 can be seen as an alternative variant. Moreover, it is also conceivable that a magnetic element 16 and electrodes 20, 21 are arranged both in the region of the runner 24 and in the region of the gate 13.

(36) In the present exemplary embodiment, it can be provided that the magnetic element 16 and/or the electrodes 20, 21 are embedded into the sand of the mold 7, such that they can be removed from the mold 7 upon destruction of the same and can be made available for use in further molds 7.

(37) FIG. 4 shows a further exemplary embodiment of gravity casting device, wherein, in this exemplary embodiment, the mold 7 and the flow connection element 11, in particular the runner 24, are formed as separate components. Here, the magnetic element 16 and/or the electrodes 20, 21 can be arranged in the region of the runner 24. In such an exemplary embodiment, one and the same runner 24 can be used for different molds 7, wherein the magnetic element 16 and/or the electrodes 20, 21 do not have to be separately integrated into each mold 7.

(38) FIG. 5 shows a further and possibly independent embodiment of the casting device 1, wherein again, equal reference numbers and/or component designations are used for equal parts as before in FIGS. 1 to 4. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIGS. 1 through 4 preceding it.

(39) In this exemplary embodiment, the casting device 1 has multiple mold cavities 10. Here, the individual mold cavities 10 are each flow-connected with the runner 24 via the gate 13. Here, it can be provided that, in the region of each of the gates 13, a magnetic element 16 and/or an electrode 20, 21 is arranged.

(40) The filling of each of the mold cavities 10 can be controlled individually by means of the individual magnetic elements 16 and/or the electrodes 20, 21.

(41) FIG. 6 shows a further and possibly independent embodiment of the casting device 1, wherein again, equal reference numbers and/or component designations are used for equal parts as before in FIGS. 1 to 5. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIGS. 1 through 5 preceding it.

(42) In this exemplary embodiment of the FIG. 6, the casting device 1 is formed as a continuous casting device. Here, the melt 4 is directed into the mold 7, which is formed as an ingot mold, via the flow connection element 11, which, in this case, is formed as a casting tube. The melt 4 solidifies in the mold 7 at least in an edge region and thus, can be directed through the mold 7 in a continuous manner. As it can be seen in FIG. 6, it can be provided that the magnetic element 16 and/or the electrodes 20, 21 are integrated into the mold 7, in particular into the ingot mold. Moreover, it is also conceivable, as an alternative or an addition, that the magnetic element 16 and the electrodes 20, 21 are integrated into the flow connection element 11 and/or are arranged in the region of the flow connection element 11.

(43) In FIGS. 7 to 11, different exemplary embodiments of cross-sections of flow connection elements 11 and/or of arrangements of the magnetic elements 16 and the electrodes 20, 21 are shown, wherein again, equal reference numbers and/or component designations are used for equal parts as in the respective preceding figures. Each of these exemplary embodiments of a possible flow cross-section is applicable to each of the exemplary embodiments of casting devices 1 as described in FIGS. 1 to 6.

(44) In the exemplary embodiment according to FIG. 7, the flow connection element 11 has a rectangular cross-section, wherein the electrodes 20, 21 are arranged on two opposing sides. On each of the two other opposing sides of the flow connection element 11, a magnetic element 16 is arranged offset to the aforementioned by 90°. Here, the cross-section of the flow connection element 11 is not surrounded by the magnetic element 16.

(45) FIG. 8 shows a further exemplary embodiment of the cross-section of the flow connection element 11. As it can be seen in FIG. 8, it can be provided that the flow connection element 11 has a rectangular cross-section and the electrodes 20, 21 are arranged on opposing sides of said cross-section. Here, the flow connection element 11 can be enclosed by the magnetic element 16. Here, the magnetic element 16 can have an annular cross-section.

(46) In a further exemplary embodiment not depicted, it is also conceivable, analogously to FIG. 8, that the magnetic element 16 does not have an annular cross-section but rather a rectangular cross-section that is adapted to the flow connection element 11.

(47) In the exemplary embodiment according to FIG. 9, both the flow connection element 11 and the magnetic element 16 have a circular cross-section. Here, the magnetic element 16 is arranged so as to surround the flow connection element 11. In this exemplary embodiment, the two electrodes 20, 21 are arranged diametrically opposed on the inner jacket surface 19 of the flow connection element 11.

(48) In the further exemplary embodiment according to FIG. 10, the flow connection element 11 is formed in the form of a channel which has no closed cross-section. Here, the magnetic element 16 can also be formed to surround the flow connection element 11.

(49) In a further exemplary embodiment according to FIG. 11, the flow connection element 11 is also formed as a channel as the magnetic element 16 does not surround the flow connection element 11, but rather, analogously to FIG. 7, two magnetic elements 16 positioned opposite one another are formed.

(50) In a further exemplary embodiment according to FIG. 12, the electrodes 20, 21 in the flow connection element 11 are not arranged opposite each other but rather are arranged one after the other when viewed in the conveying direction 23. Here, it can be provided that the electrodes 20, 21 are arranged on one side of the flow connection element 11.

(51) FIG. 13 shows a further exemplary embodiment of the arrangement of the electrodes 20, 21, wherein, in this exemplary embodiment, the electrodes 20, 21 are, analogously to FIG. 12, also arranged one after the other and/or spaced from one another when viewed in the conveying direction 23. In this exemplary embodiment, the electrodes 20, 21 are respectively formed, for example, in the form of circumferential or at least partly circumferential electrode rings.

(52) In a further exemplary embodiment not depicted, it is also conceivable that the electrodes 20, 21 are formed, for example in the form of rods, for example made from carbon, which rods are stuck through the flow cross-section. Electrodes formed in such a way can also, for example, be formed to be axially spaced from one another.

(53) In particular, it can be provided that the electrodes 20, 21 and the electromagnet 17 are subjected to alternating current, wherein the alternating current applied to the electrodes 20, 21 and the alternating current applied to the electromagnet 17 are phase-shifted relative to one another or can be actively phase-shifted such that a magnetic force 22 acts on the melt 4 exclusively in the desired direction.

(54) FIG. 14 shows a further and possibly independent embodiment of the low pressure ingot mold casting device and/or counter pressure ingot mold casting device, wherein again, equal reference numbers and/or component designations are used for equal parts as before in FIG. 1. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIG. 1 preceding it.

(55) As it can be seen in FIG. 14, it can be provided that the first electrode 20 and the second electrode 21 are shorted with one another by means of a current bridge 27. Such a current bridge may, of course, be applied in any and all of the described embodiments of the electrodes 20, 21.

(56) Of course, all exemplary embodiments described above allow the use of either a coil 18 or also a permanent magnet.

(57) The exemplary embodiments show possible embodiment variants, and it should be noted in this respect that the invention is not restricted to these particular illustrated embodiment variants of it, but that rather also various combinations of the individual embodiment variants are possible and that this possibility of variation owing to the teaching for technical action provided by the present invention lies within the ability of the person skilled in the art in this technical field.

(58) The scope of protection is determined by the claims. However, the description and the drawings are to be adduced for construing the claims. Individual features or feature combinations from the different exemplary embodiments shown and described may represent independent inventive solutions. The object underlying the independent inventive solutions may be gathered from the description.

(59) All indications regarding ranges of values in the present description are to be understood such that these also comprise random and all partial ranges from it, for example, the indication 1 to 10 is to be understood such that it comprises all partial ranges based on the lower limit 1 and the upper limit 10, i.e. all partial ranges start with a lower limit of 1 or larger and end with an upper limit of 10 or less, for example 1 through 1.7, or 3.2 through 8.1, or 5.5 through 10.

(60) Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size.

LIST OF REFERENCE NUMBERS

(61) 1 casting device 2 furnace 3 receiving space 4 melt 5 crucible 6 platen 7 mold 8 lower mold part 9 upper mold part 10 mold cavity 11 flow connection element 12 riser tube 13 gate 14 supporting structure 15 compressed air supply opening 16 magnetic element 17 electromagnet 18 coil 19 inner jacket surface 20 first electrode 21 second electrode 22 magnetic force 23 conveying direction 24 runner 25 sprue 26 feeder 27 current bridge