CASTING FILTER

Abstract

Casting filter, in particular for filtering and/or purifying a metal melt, having a cell structure for passing through a metal melt and having a supporting structure for reinforcing the cell structure, the cell structure and/or the supporting structure being produced at least in sections from a ceramic material, the cell structure being formed by a plurality of cells which are delimited from one another by cell walls, wherein at least one of the cells has a constant cross-sectional shape along a flow orientation, wherein at least one of the cell walls has a wall thickness of less than 1 mm, and wherein the supporting structure is formed by at least one supporting wall which extends at least in sections between adjacent cells and whose wall thickness is greater, at least in sections, than the wall thickness of a cell wall.

Claims

1. A casting filter for filtering and/or purifying a metal melt, comprising: a cell structure for passing through a metal melt; and a supporting structure for reinforcing the cell structure, wherein. the cell structure and/or the supporting structure are produced, at least in sections, from a ceramic material, the cell structure comprises a plurality of cells which are delimited from one another by cell walls, at least one of the plurality of cells has a constant cross-sectional shape along a flow orientation, at least one of the cell walls has a wall thickness of less than 1 mm, and the supporting structure is formed by at least one supporting wall which extends at least in sections between adjacent cells and whose wall thickness is greater, at least in sections, than the wall thickness of a cell wall.

2. The casting according to claim 1, wherein the at least one of the cell walls has a wall thickness of less than 0.75 mm.

3. The casting filter according to claim 1, wherein two or more cells have an identical shape.

4. The casting filter according to claim 1, wherein at least one of the plurality of cells has a hexagonal cross-sectional shape.

5. The casting filter of claim 1, wherein the cell structure and/or at least one of the plurality of cells and/or cell walls has a height extending in the flow orientation of less than 6 mm.

6. The casting filter of claim 1, wherein the supporting structure has a plurality of supporting walls, which run at an angle to one another and/or from an edge region of the cell structure into an inner region of the cell structure and/or converge towards one another in an inner region of the cell structure.

7. The casting filter of claim 1, wherein the supporting wall has a wall thickness of less than 0.8 mm.

8. The casting filter of claim 1, wherein a wall height of the supporting wall is, at least in sections, greater than a wall height of at least one of the cell wall.

9. The casting filter of claim 1, wherein the cell structure is enclosed, at least in sections, by a frame structure having a stepped design, which is arranged in the flow orientation in a stepped manner and/or which has an outer circumferential size which decreases stepwise or narrows in a flow direction and/or which has at least one step running along a frame outer circumference.

10. The casting filter according to claim 9, wherein the frame structure comprises at least one frame wall with a maximum wall thickness of less than 2 mm.

11. The casting filter according to claim 10, wherein the frame structure and/or the at least one frame wall has a wall section which protrudes from an end plane of the cell structure and/or protrudes in the flow orientation, in or against a flow direction, relative to at least one of the cells and/or cell walls and/or protrudes by more than 1 mm.

12. The casting filter of claim 1, wherein one or more of the cell structure, the supporting structure, and the frame structure are produced at least in sections by 3-D printing, and/or formed in one piece.

13. The casting filter of claim 1, wherein one or more of the cell structure, the supporting structure, and the frame structure are produced, at least in sections, from one or more an oxide ceramic, a non-oxide ceramic, a composite ceramic, and an aluminum-based ceramic material.

14. (canceled)

15. A process for producing a metal component, comprising passing a metal melt through the casting filter according to claim 1; and then solidifying the metal melt within a casting mold.

16. A method for producing the casting filter of claim 1, comprising 3-D screen printing, layer-by-layer, one or more the filter structure, the cell structure, the supporting structure, and the frame structure.

17. The casting filter of claim 1, wherein the cell structure is bounded by boundary cells and the shape of at least one of the boundary cells differs from the shape of an inner cell.

18. The casting filter of claim 4, wherein the hexagonal cross-sectional shape extends transversely to the flow orientation and/or the hexagonal cross-sectional shape is an equilateral hexagonal cross-sectional shape.

19. The casting filter of claim 1, wherein the supporting structure subdivides the cell structure into a plurality of cell structure portions in a cake-like manner.

20. The casting filter of claim 1, wherein the cell structure is enclosed, at least in sections, by a frame structure with a plurality of steps which are formed on the frame outer circumference.

21. The casting filter of claim 1, wherein the at least one supporting wall has a wall section which projects with respect to the cell structure from a terminal plane cell structure and/or projects in the flow orientation, in or against a flow direction, with respect to at least one of the cells and/or cell walls and/or projects by more than 1 mm.

22. The method of claim 15, wherein the metal component is an aluminum rim.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In the following, the invention is described as an example with reference to the attached figures. It is shown, schematically in each case:

[0052] FIG. 1 is a perspective view of an inventive casting filter according to an embodiment;

[0053] FIG. 2 is a top view of the casting filter of FIG. 1;

[0054] FIG. 3 is a detailed view of the casting filter according to FIG. 2;

[0055] FIG. 4 is a top view of an inventive casting filter according to an embodiment;

[0056] FIG. 5 is a side view of an inventive casting filter according to an embodiment;

[0057] FIG. 6 is a side view of a casting filter according to another embodiment;

[0058] FIG. 7 is a side view of an inventive casting filter according to an even further embodiment; and

[0059] FIG. 8 is a perspective view of an inventive casting filter according to another embodiment.

DETAILED DESCRIPTION

[0060] FIGS. 1 to 3 show a casting filter 10 according to a first embodiment of the invention. FIG. 1 shows a perspective view from one side of the inflow side. The upper side shown in FIG. 1 can thus be a inflow side from which a metal melt flows into the casting filter 10. A top view of the pouring filter 10 is shown in FIG. 2 and FIG. 3 shows a detailed view of the section marked A in FIG. 2.

[0061] The casting filter 10 has a cell structure 12 by passing through a metal melt and a supporting structure 14 to reinforce the cell structure 12. The cell structure 12 and also the supporting structure 14 can be made at least in sections from a ceramic material, in particular completely from a ceramic material. Preferably, the entire casting filter 10 can be made of a ceramic material. Furthermore, the entire casting filter 10 can be made in one piece, in particular it can consist of a single material.

[0062] The cell structure 12 is formed by a plurality of cells 16, which are delimited to each other by cell walls 18. Cells 16 form flow channels through which a molten metal can flow along a flow orientation marked with the reference sign 20. The flow orientation 20 runs along a longitudinal axis of the casting filter 10.

[0063] Cells 16 have a constant cross-sectional shape along the flow orientation 20. In the present embodiment, cells 16 have a hexagonal cross-sectional shape which remains unchanged along flow orientation 20. The respective cells 16 thus have an inflow and an outflow opening with identical cross-sectional shape.

[0064] Details of the cell structure 12 and the supporting structure 14 are shown in FIG. 3. The cell walls 18 have a wall thickness 22, which may be less than 1 mm, in particular approx. 0.3 mm. Furthermore, the supporting structure 14 may be formed by at least one supporting wall 24 which runs at least in sections between adjacent cells 16 and whose wall thickness 26 is at least in sections greater than the wall thickness 22 of a cell wall 18. The wall thickness 26 of a supporting wall may be 0.625 mm, for example. In the embodiment shown in FIGS. 1 to 3, a total of three supporting walls 24 are provided which divide the cell structure 12 into three approximately equally sized cake-shaped cell structure sections.

[0065] It can also be seen from FIGS. 1 to 3 that a majority of the cells 16 have the same shape. Only in a boundary area of the cell structure 12 boundary cells are formed, whose shape differs from that of the inner cells 16.

[0066] In FIGS. 1 to 3 a central portion 28 is hidden. In this central portion 28, different geometric configurations can be provided. For example, the supporting walls 24 in central portion 28 can merge into each other and cells 16 can be arranged in a repeating pattern up to central area 28. It is also possible to provide a supporting structure for a hold-down device in central portion 28, which is not explained in detail here.

[0067] In FIG. 3 further dimensions of cell structure 12 are designated. In particular, a length of a cell wall 18 is designated with the reference sign 30 and the distance between two opposite cells 18 of a cell 16 is designated with 32. The length 30 of a cell wall can be 1.5 mm, for example, and the distance 32 between two opposite cell walls 18 can be 2.6 mm, for example. The height of the cell structure 12 or the cell walls 18, which extends in flow orientation 20, can be 4.2 mm, for example. The height of the supporting walls 24 can be identical to the height of the cell walls 18, and it is also possible that the height of the supporting walls 24 deviates from the height of the cell walls 18.

[0068] In the embodiment shown in FIGS. 1 to 3, the supporting walls 24 run linearly through the cell structure 12. The supporting walls 24 partly border adjacent cells 16 with hexagonal cross-sectional shape. Likewise, the course of the linear supporting walls 24 according to FIGS. 1 to 3 causes cells 16 with a hexagonal cross-sectional shape to be divided by a wall section of the supporting wall 24 into two cells of equal size, each with a trapezoidal cross-sectional shape.

[0069] FIG. 4 shows a top view of a casting filter 10 according to another version of the invention. The embodiment according to FIG. 4 differs from the embodiment according to FIGS. 1 to 3 only in the design of the supporting structure 14. In the embodiment according to FIG. 4, the supporting structure 14 is also formed by a total of three supporting walls 24, although these do not run linearly through the cell structure 12, but have wall sections running at an angle to each other. By means of these wall sections running at an angle to one another, the respective supporting wall 24 can reproduce the hexagonal cross-sectional shape of the respective adjacent cells 16 or limit the respective cells 16 in a corresponding manner, without individual cells with hexagonal cross-sectional shape being divided by the supporting wall 24 into two cells with trapezoidal cross-sectional shape. This embodiment according to FIG. 4 allows a more uniform cell design.

[0070] FIGS. 1, 2 and 4 also show that the cell structure 12 is enclosed by a frame structure 34. The frame structure 34 has a circular outer circumferential shape and a circular inner circumferential shape. Other outer circumferential and inner circumferential geometries are also possible, such as polygonal inner circumferential and outer circumferential geometries.

[0071] The frame structure 34 limits a flow area for a molten metal. The frame structure 34 can have a frame wall with a maximum wall thickness of about 1.5 mm. It is possible that the frame structure 34 has a constant wall thickness along the flow orientation 20 or a changing wall thickness, especially by the formation of steps 36.

[0072] Different designs with respect to the shape of the frame structure 34 or the frame wall of the frame structure 34 are shown in the side views according to FIGS. 5 to 7. FIG. 5 shows a side view of a casting filter 10 according to the invention with a frame structure 34, which is free of steps on its outer circumference. According to FIG. 6, a frame structure 34 is provided, which is formed in a stepped like manner in a flow orientation 20 or has an outer circumference that decreases stepwise in flow direction 40. For this purpose, a step 36 running along an outer circumference of the frame is provided. By means of such a step 36, the casting filter 10 can be supported positively within a gating system of a casting mold, so that an overall higher operational safety can be achieved. According to FIG. 7, a number of steps 36 are provided, which further improves the support safety.

[0073] FIG. 8 shows a further design of a pouring filter 10. The upper side shown in FIG. 8 is an outflow side of the pouring filter 10. Hatched in FIG. 8 is the cell structure 12 or an end level of the cell structure 12. Furthermore, the supporting walls 24 of the frame structure 14 are shown schematically.

[0074] It can be seen from FIG. 8 that the supporting walls 24 of the supporting structure 14 project from the end plane of the cell structure 12. Accordingly, the supporting walls 24 have a wall section 37 which protrudes from cell structure 12, in particular from the cell plane hatched in FIG. 8. In particular, the projecting wall section 37 may have a height of approx. 1.3 mm.

[0075] The projecting design of the supporting walls 24 can also be provided for the frame structure 34. Thus, it can also be seen from FIG. 8 that the frame structure 34 has a frame wall section 38 which protrudes in the flow direction from the end plane of the cell structure 12 hatched in FIG. 8. The height of the projecting wall section of the frame structure 34 can also be approximately 1.3 mm. The flow direction is shown in FIG. 8 with the arrow designated by reference sign 40.

[0076] With a design according to FIG. 8 on the one hand a sufficient mechanical stability of the casting filter 10 can be ensured without the cell structure 12 having to have an excessive height in flow orientation 20, which would have a negative effect on the flow resistance. A casting filter 10 of this type thus has favorable filter and cleaning properties with high operational reliability.

[0077] A casting filter 10 according to the embodiments in FIGS. 1 to 8 can be manufactured in a particularly preferred way by 3D screen printing. In this way, variations along the longitudinal axis or along the flow orientation 20 can be realized in a particularly advantageous manner without incurring excessive costs. In a suitable manner, a casting filter 10 can be produced from an oxide ceramic, especially from an aluminum-based ceramic material. Such a ceramic material can be formed as aluminum oxide, aluminum nitride or aluminum titanate, for example. By using an aluminum-based ceramic material, an undesirable influence of foreign atoms can be avoided when casting an aluminum melt, for example for the production of automobile rims. In this way, the casting quality can be improved.

[0078] The forms of execution described above and the general concepts described in the introduction to the description can be combined or varied at will. For example, a casting filter according to FIG. 8 can also be designed with steps 36 according to the designs in FIG. 6 or 7, although this is not shown in detail. Likewise, a casting filter 10 can be designed according to the design in FIGS. 1 to 3 or according to the design in FIG. 4 with projecting wall sections according to FIG. 8, although this is not shown in detail.

[0079] A casting filter 10 according to the invention is particularly advantageous for casting an aluminum melt or for casting other metal melts, for example a melt of steel. In particular, a casting filter 10 is suitable for the casting of aluminum rims or other aluminum components for use in the automotive industry.

[0080] The process described above for the production of a casting filter or the process that can be carried out with an apparatus for the production of a casting filter is the Exentis 3D Mass Customization method.

LIST OF REFERENCE SIGNS

[0081] 10 casting filter

[0082] 12 cell structure

[0083] 14 supporting structure

[0084] 16 cells

[0085] 18 cell wall

[0086] 20 flow orientation

[0087] 22 wall thickness of a cell wall

[0088] 24 supporting wall

[0089] 26 wall thickness of a supporting wall

[0090] 28 central portion

[0091] 30 length of a cell wall

[0092] 32 distance between opposite cell walls

[0093] 34 frame structure

[0094] 36 step

[0095] 37 protruding wall section

[0096] 38 protruding wall section

[0097] 40 flow direction