Alloy casting apparatus

Patent metadata

Field	Value
Publication number	US-9427803-B2
Application number	US-66180305-A
Country	US
Kind code	B2
Filing date	Sep 1, 2005
Priority date	Sep 1, 2004
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

Apparatus for gravity flow and feeding of alloy in a casting operation has a supply vessel for holding a supply of alloy, a furnace in which the vessel is contained and in which the vessel is heatable to maintain the supply of alloy at suitable casting temperature, and a die mounted laterally outwardly from the vessel in relation to the furnace. A conduit provides communication between the vessel and the die. The apparatus further includes means for reversibly tilting an assembly including the furnace, the vessel and the die about a substantially horizontal axis to enable or prevent the flow of the alloy from the vessel to a die cavity defined by the die.

First claim

The invention claimed is:

1. A casting apparatus which enables gravity flow and feeding of alloy in a casting operation, the apparatus comprising:
a supply vessel for holding a supply of alloy,
a furnace in which the vessel is contained and in which the vessel is heatable to maintain the supply of alloy at a suitable casting temperature,
a permanent mould located outside of the vessel and the furnace mounted laterally outwardly from the vessel and the furnace, the mould having dies defining a die cavity,
a conduit providing communication between the vessel and the mould, the conduit having a main part of its length which extends through and outwardly from the furnace and slopes downwardly relative to the vessel, and
a drive element operable to reversibly tilt an assembly including the furnace, the vessel and the mould about a substantially horizontal axis to enable or prevent the flow of the alloy through the conduit from the vessel to the die cavity defined by the dies under a pressure head of alloy in the supply vessel, and throughout a range of tilting of the assembly, from a first, non-casting position the assembly occupies on completion of one cycle and before commencement of the next cycle and in which the flow of alloy from the vessel to the die cavity is prevented, to a second, casting position enabling flow from the vessel to the die cavity, to generate the pressure and produce a casting, the mould having a lower die by which alloy is able to be received upwardly into the die cavity by flowing upwardly from the conduit and by which the mould is mounted in relation to the furnace, and an upper die which is moveable relative to the lower die and the furnace for opening and closing the mould, the mould being provided with an arrangement connectable to a source of supply of protective cover gas and enabling the flow of protective cover gas to the die cavity for protecting a surface of molten alloy, at a second end of the conduit, said arrangement including a chamber into which the protective gas is receivable, said arrangement having a plurality of outlets by which the chamber communicates with the die cavity, said arrangement being operable to provide protective cover gas at a positive pressure to the mould for flow into the die cavity on solidification of alloy therein and just prior to tilting of the assembly from the second, casting position to the first, non-casting position whereby, as molten alloy retracts from the mould as the pressure head is reduced, the positive pressure of protective cover gas and a resultant reduction in pressure at the second end of the conduit enabling protective cover gas to flow into the second end of the conduit for protecting the surface of molten alloy in the second end of the conduit, when the mould is open,
wherein the main part of the conduit slopes at an angle of from about 5° to 15° from a top horizontal surface of the vessel.

2. The apparatus of claim 1 , wherein the drive element operable to reversibly tilt the assembly is operable for tilting the assembly to a third, storage position which is beyond the first, non-casting position in a direction away from the casting position and in which alloy in the conduit is able to drain into the vessel.

3. The apparatus of claim 2 , wherein the drive element to tilt the assembly is operable for tilting the assembly away from the third, storage position, through and beyond the second, casting position to a fourth, alloy emptying position.

4. The apparatus of claim 1 , wherein the vessel is able to hold a volume of molten alloy which is substantially larger than the volume of alloy consumed in a casting cycle.

5. The apparatus of claim 1 , wherein the conduit has a first end at the vessel at a location which is below the level of alloy in the vessel when the assembly is in the first, non-casting position, whereby a pressure head of molten alloy above that location is able to be maintained during pivoting of the assembly from the first, non-casting position to the second, casting position and whereby the pressure head of alloy increases as the assembly tilts from the first, non-casting to the second, casting position.

6. The apparatus of claim 5 , wherein with the assembly in the second, casting position, the pressure head is at a maximum, with the level of alloy in the vessel sufficiently above the highest point in the die cavity to ensure complete die cavity fill.

7. The apparatus of claim 5 , wherein, from the location for the first end of the conduit, the conduit passes away from the vessel, and laterally through a wall of the furnace and outwardly to a second end at the mould, and wherein the conduit communicates with the mould in a manner enabling alloy to flow upwardly in, and fill, the die cavity under the pressure head of alloy established in the vessel when the assembly is in the second, casting position.

8. The apparatus of claim 7 , wherein the conduit communicates with the die cavity at a location which, with the assembly in the first, non-casting position is directly below the die cavity.

9. The apparatus of claim 1 , wherein a first part of the conduit within the furnace is heatable by the furnace, thereby reducing the risk of excessive cooling of the alloy in the flowing to the die, and a second part of the conduit between the furnace and the mould is protected from excessive cooling.

10. The apparatus of claim 9 , wherein the conduit is of a refractory thermal insulating material.

11. The apparatus of claim 9 , wherein the second part of the conduit is heatable by an electric resistance coil around the second part.

12. The apparatus of claim 9 , wherein the second part of the conduit is provided with an insulation sleeve.

13. The apparatus of claim 1 , wherein the relative lengths of the main part remote from the vessel has a shorter part which extends upwardly to the lower die.

14. The apparatus of claim 13 , wherein the relative lengths of the main and shorter parts, and the angle at which the main part slopes downwardly from the horizontal, are such that an angle of pivoting of from 15° to 30° is necessary to enable the assembly to pivot between the first, non-casting and second, casting positions.

15. The apparatus of claim 1 , wherein the vessel includes a trough which is U-shape in cross-sections perpendicular to the pivot axis, the conduit extends from one of the opposite side walls defined by the U-shape, and the pivot axis is offset from the center of the vessel towards the other one of the walls.

16. The apparatus of claim 15 , wherein the vessel has a cover which enables maintenance of a protective atmosphere over the surface of the alloy.

17. The apparatus of claim 15 , wherein the vessel has a transverse baffle or partition which divides the interior of the vessel into two chambers or sections, the conduit extends from a first chamber or section of the two chambers or sections, and the vessel is adapted for fresh alloy to be supplied to the second chamber or section.

18. The apparatus of claim 17 , wherein the baffle enables fresh alloy supplied to the second chamber or section to flow through to the first chamber or section from which the conduit extends, while preventing solid lumps of alloy present in the second chamber or section from impeding alloy flowing from the first chamber or section to the conduit during a casting operation.

19. The apparatus of claim 1 , wherein the protective cover gas is able to flow into the die cavity along one or more channels formed in one or more of the dies at a parting plane.

20

Assignees

• Carrig John Francis
• De Looze Geoffrey
• Nguyen Thang Tran
• Alguine Vladimir Nikolai
• Commw Scient Ind Res Org

Inventors

• Carrig John Francis
• De Looze Geoffrey
• Nguyen Thang Tran
• Alguine Vladimir Nikolai

Classifications

• B22D41/04

  tiltable · CPC title

• B22D23/006 Primary

  Casting by filling the mould through rotation of the mould together with a molten metal holding recipient, about a common axis · CPC title

• B22D21/04

  Casting aluminium or magnesium {(no material; see B22D21/007)} · CPC title

• B22D37/00

  Controlling or regulating the pouring of molten metal from a casting melt-holding vessel ({B22D11/18,} B22D39/00, B22D41/00 take precedence) · CPC title

• B22D23/00 Primary

  Casting processes not provided for in groups B22D1/00 - B22D21/00 (making metallic powder by casting B22F9/08; alumino-thermic welding B23K23/00; remelting metals C22B9/16) · CPC title