Feeder system

Abstract

The invention relates to a feeder system for use in a metal casting operation utilizing a casting mold, and to a feeder sleeve for use in a feeder system. A feeder system for a metal casting is provided, the feeder system including a feeder sleeve mounted on a necked down core, the feeder sleeve having a first end and an opposite second end, a longitudinal axis extending between the first end and the second end, and a continuous sidewall extending generally about the longitudinal axis between the first end and the second end, the sidewall defining a cavity for receiving molten metal during casting, and the necked down core defining an aperture therethrough for connecting the cavity to the casting, wherein the first end of the feeder sleeve is mounted on the necked down core, and the feeder sleeve includes at least one protrusion extending from an outer surface of the sidewall at the second end of the feeder sleeve.

Description

Technical Field

[0001] The present invention relates to a feeder system for use in metal casting operations utilizing casting molds, and to a feeder sleeve for use in the feeder system. Background Technology

[0002] In a typical casting process, molten metal is poured into a pre-formed mold cavity that defines the shape of the casting. However, the metal shrinks as it solidifies, resulting in shrinkage cavities, which in turn lead to unacceptable defects in the final casting. This is a well-known problem in the casting industry and is addressed by using feeder sleeves or risers integrated into the mold. Each feeder sleeve provides an additional (usually closed) volume or cavity communicating with the mold cavity, allowing molten metal to enter the feeder sleeve from the mold cavity during casting. During the solidification of the casting, the molten metal within the feeder sleeve flows back into the mold cavity to compensate for the casting's shrinkage.

[0003] Molding practices are well-known and are described, for example, in Chapters 12 and 13 of the Foseco Ferrous Foundryman's Handbook (ISBN 075064284 X).

[0004] For large castings, foundry operators may need to walk on the top surface of the mold to perform tasks such as applying coatings to the outside of the mold. After the mold is formed, the feeder sleeve may protrude above the mold material. If a foundry operator accidentally steps on a protruding feeder sleeve, the feeder sleeve may sink into the mold through the feeder recess and protrude into the casting cavity, or fall completely out of the feeder recess and into the casting cavity. If the displacement of the feeder sleeve is not noticed before pouring the molten metal, or if a mold replacement is required (both of which are expensive and detrimental to productivity), this can cause serious defects in the casting.

[0005] This invention was designed with these problems in mind. Summary of the Invention

[0006] According to a first aspect of the invention, a feeder system for metal castings is provided, the feeder system comprising a feeder sleeve mounted on a breaker core. The feeder sleeve has a first end and an opposite second end, a longitudinal axis extending between the first and second ends, and a continuous sidewall extending substantially around the longitudinal axis between the first and second ends. The sidewall defines a cavity for receiving molten metal during casting, and the breaker core defines an opening therethrough for connecting the cavity to the casting. The first end of the feeder sleeve is mounted on the breaker core. The feeder sleeve includes at least one protrusion extending from the outer surface of the sidewall at the second end of the feeder sleeve.

[0007] In use, the necked core will come into contact with the casting cavity. The necked core on which the feeder sleeve is mounted can be of any type, including disc-shaped necked cores made of resin-bonded sand or ceramic materials, or foldable metal necked cores (e.g., those described in Foseco's PCT application WO 2016 / 166497). It should be understood that the first end of the feeder sleeve will be suitably configured for mounting on the selected type of necked core, and the necked core can be attached to the feeder sleeve by any suitable method (e.g., adhesive, friction fit, locking mechanism, etc.).

[0008] During casting, the feeder sleeve will be oriented such that the first end (attached to the necked core) is at the bottom and the second end is at the top. If the feeder sleeve is accidentally stepped on after the mold is formed, at least one protrusion at the top of the feeder sleeve (i.e., at the second end) abuts against the mold material surrounding the sidewall and thus resists downward movement, thereby preventing the feeder sleeve from sinking through the mold and falling into the casting cavity.

[0009] Preferably, at least one protrusion extends from the outer surface of the sidewall in a direction perpendicular to the longitudinal axis of the feeder sleeve.

[0010] In this embodiment, the sidewalls of the feeder sleeve are cylindrical. The cross-sectional shape of the cylindrical body can typically be circular, oval, or elliptical. In this embodiment, the diameter of the cylindrical body is typically constant from the first end to the second end. Alternatively, the diameter at the first end of the feeder sleeve can be larger than the diameter at the second end, and vice versa. In this embodiment, the sidewalls of the feeder sleeve are typically cylindrical and have a truncated conical portion located towards the first end of the feeder sleeve, which tapers gradually toward the necked core.

[0011] In one embodiment, the top (i.e., the second end) of the feeder sleeve is open or includes a hole through it. In such an embodiment, molten metal can be poured directly into the casting cavity through the feeder, and the feeder system may include a filter for filtering the molten metal before it enters the casting cavity. Preferably, the hole is centrally located. In an alternative embodiment, the top of the feeder sleeve is closed.

[0012] In one embodiment, at least one protrusion is integrally formed with the sidewall. In such an embodiment, the feeder sleeve (including one or more protrusions) can be formed using a one-piece molding process. Alternatively or additionally, at least one protrusion is attached to a separate part of the feeder sleeve by any suitable means (e.g., adhesive, rivet, press fit, etc.). In such an embodiment, the protrusion can be made of the same material as the feeder sleeve (e.g., resin-bonded sand) or of a different material (e.g., metal or plastic).

[0013] In one embodiment, at least one protrusion extends outward from the sidewall (i.e., perpendicular to the longitudinal axis of the feeder sleeve) to a distance of at least 5%, 10%, 20%, or 30% of the maximum diameter of the feeder sleeve. In another embodiment, at least one protrusion extends outward from the sidewall to a distance not exceeding 35%, 30%, 25%, 20%, 15%, or 10% of the maximum diameter of the feeder sleeve. In yet another embodiment, at least one protrusion extends outward to a distance of 5% to 35%, 5% to 20%, or 5% to 15% of the maximum diameter of the feeder sleeve. It should be understood that the maximum diameter of the feeder sleeve does not include at least one protrusion and is measured from the outer surface of the sidewall on one side of the sleeve to the outer surface of the sidewall on the opposite side of the sleeve at the second end where at least one protrusion of the feeder sleeve is located.

[0014] In one embodiment, at least one protrusion extends from the second end of the feeder sleeve toward the first end at least 4%, 5%, 10%, 15%, or 20% of the maximum height of the feeder sleeve (measured in the direction of the longitudinal axis). In another embodiment, at least one protrusion extends from the second end of the feeder sleeve toward the first end at no more than 25%, 20%, 15%, 10%, or 5% of the maximum height of the feeder sleeve. Preferably, at least one protrusion extends from the second end toward the first end at 4% to 25%, 4% to 15%, or 5% to 10% of the maximum height of the feeder sleeve. It should be understood that the maximum height of the feeder sleeve is measured from the second end to the first end of the feeder sleeve, excluding the necked core.

[0015] At least one protrusion may take the form of a plurality of discrete protrusions spaced apart around the periphery of the second end of the feeder sleeve. Alternatively, the at least one protrusion may take the form of an annular collar or edge extending around the entire periphery of the second end of the feeder sleeve. It should be understood that any of the embodiments mentioned above may be freely combined with a plurality of discrete protrusions or annular collars / edges.

[0016] In embodiments where at least one protrusion is a plurality of discrete, spaced-apart protrusions, the at least one protrusion may include at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 spaced-apart protrusions. In embodiments, the at least one protrusion includes 2 to 10 spaced-apart protrusions. Preferably, the at least one protrusion includes 3 or 4 spaced-apart protrusions. Providing more than 4 spaced-apart protrusions increases the resistance of the feeder sleeve to downward movement by increasing the area against the mold material, but reduces the number of sleeves that can be manufactured in a single molding process within a given timeframe. Providing 3 or 4 spaced-apart protrusions offers an optimal balance between sufficient resistance to downward movement and good production efficiency.

[0017] In some embodiments, each of the spaced-apart protrusions extends about 5%, 10%, 15%, 20%, or 25% of the circumference of the second end of the feeder sleeve. In some embodiments, each of the spaced-apart protrusions extends about 3%, 5%, 10%, 15%, or 20% of the circumference of the second end of the feeder sleeve. Preferably, each of the spaced-apart protrusions extends about 3% to 25%, 3% to 20%, or 5% to 15% of the circumference of the second end of the feeder sleeve.

[0018] In some embodiments, the spaced-apart protrusions are evenly distributed around the periphery of the second end of the feeder sleeve, such that the centers of each protrusion are equidistant from each other. For example, the distance between the centers of the protrusions may be at least 5%, 10%, 20%, 30%, 40%, or 50% of the circumference of the edge, or not more than 50%, 40%, 30%, 20%, 10%, or 5% of the circumference of the edge. In other embodiments, the spaced-apart protrusions are unevenly distributed around the periphery of the second end of the feeder sleeve, such that some of the protrusions are closer together and some are further apart. Preferably, the protrusions are symmetrically arranged around the periphery of the second end and have at least one plane of symmetry.

[0019] In embodiments, the spaced-apart protrusions have a semi-circular, quarter-circular, wedge-shaped, or square cross-section. In embodiments with a semi-circular or quarter-circular cross-section, the protrusions may be hemispherical or quarter-spherical. Preferably, each of the protrusions has the same cross-sectional shape and the same dimensions. In embodiments, the protrusions may be discrete protrusions forming, for example, a scalloped arrangement, in a continuous series.

[0020] Preferably, each of the spaced-apart protrusions has the same shape and size. However, in some embodiments, the protrusions may vary in shape or size.

[0021] In embodiments where at least one protrusion is an annular collar or edge, the edge may extend continuously around the periphery of the second end, or may include one or more breaks. In one embodiment, the annular edge is circular. In other embodiments, when viewed in a plan view along the longitudinal axis of the feeder sleeve, the annular edge is shaped like a polygon with at least three sides. The polygon may have at least 3, 4, 5, 6, 7, 8, 9, or 10 sides. In one embodiment, the polygon has 3 to 10 sides. The corners of the polygonal edge can effectively function as spaced-out protrusions. Preferably, the polygon has four sides, and the edge is typically square.

[0022] In this embodiment, the corners of the polygon are rounded. The radius of curvature of the rounded corners can be equal to the maximum distance the corners of the polygon protrude outward from the outer surface of the sidewall. In this embodiment, the radius of curvature of the rounded corners can be at least 10%, 25%, 50%, 75%, 90%, or 100% of the maximum distance the corners of the polygon protrude outward from the outer surface of the sidewall, or not more than 90%, 75%, 50%, 25%, or 10%. In this embodiment, the radius of curvature of the rounded corners is 10% to 100%, 25% to 100%, or 50% to 100% of the maximum distance the corners of the polygon protrude outward from the outer surface of the sidewall. The side edges can be square or rounded.

[0023] It should be understood that in embodiments where the annular edge is polygonal, the corners of the polygon will protrude outward from the outer surface of the sidewall by a greater distance than the sides of the polygon.

[0024] In a particular embodiment, the sidewall is cylindrical (having a generally circular cross-section and a generally constant diameter from the first end to the second end of the feeder sleeve), and at least one protrusion is a square edge. The corners of the square edge may be rounded. Thus, the edge does not necessarily have four 90° corners, but it can still be described as a square based on having four edges of equal length oriented at 90° to the adjacent sides.

[0025] The invention also relates to a feeder sleeve for use in a feeder system according to an embodiment of the first aspect.

[0026] According to a second aspect of the invention, a feeder sleeve for use in a metal casting is provided, the feeder sleeve including a first end and an opposite second end, a longitudinal axis extending between the first end and the second end, and a continuous sidewall extending generally around the longitudinal axis between the first end and the second end, the sidewall defining a cavity for receiving molten metal during casting, the first end of the feeder sleeve being configured for mounting on a necked core, and the feeder sleeve including at least one protrusion extending perpendicularly to the longitudinal axis from the outer surface of the sidewall at the second end of the feeder sleeve.

[0027] The above comments on the first aspect also apply to the second aspect. Attached Figure Description

[0028] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0029] Figure 1 and Figure 2 This is a schematic diagram of a feeder system according to an embodiment of the present invention;

[0030] Figure 3 yes Figure 1 and Figure 2 The plan view of the feeder system shown in the figure;

[0031] Figure 4 It shows Figure 1 and Figure 2 The diagram shows various variations of the embodiments.

[0032] Figure 5 This is a schematic diagram of a feeder system according to another embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of a feeder system according to another embodiment of the present invention; and

[0034] Figure 7 yes Figure 6 The plan view of the feeder system is shown in the figure. Detailed Implementation

[0035] refer to Figure 1The diagram illustrates a feeder system 100 including a feeder sleeve 10 mounted on a necked core 11. The feeder sleeve 10 has a first end 12 and an opposite second end 13, with a longitudinal axis A extending between the first end 12 and the second end 13. A continuous sidewall 14 extends in a generally cylindrical shape around the longitudinal axis A, thereby defining a cavity therein for receiving molten metal. The first end 12 of the feeder sleeve 10 is mounted on the necked core 11. The necked core 11 is a conventional disc core, defining an opening (not shown) through which the feeder sleeve cavity is connected to the casting.

[0036] In the depicted embodiment, the feeder sleeve 10 includes four discrete protrusions 15 extending outward from the outer surface of the sidewall 14 at a second end 13 of the feeder sleeve 10. Figure 2 As shown, the height H2 of each protrusion is 10% of the maximum height H1 of the feeder sleeve 10 (measured in the direction of the longitudinal axis A). Figure 3 As shown, the cross-sectional shape of each protrusion (as seen in the plan view along longitudinal axis A) is semicircular. The top edge of each protrusion 15 is flat and abuts the second end 13 of the feeder sleeve 10, while the bottom of each protrusion 15 is rounded. Each protrusion 15 extends from the outer surface of the sidewall 14 to a distance D2, which is 8% of the maximum diameter D1 of the cylindrical sidewall 14. Each protrusion 15 extends around the perimeter of the sidewall to a width W1, which is 5% of the circumference of the cylindrical sidewall 14. The protrusions 15 are evenly spaced around the circumference of the sidewall 14, with a width W2 between adjacent protrusions that is 20% of the circumference of the sidewall 14. In total, the coverage of the circumference of the sidewall 14 by the protrusions 15 is 20%, of which 80% of the circumference is unprotruded.

[0037] like Figure 4 As shown, the feeder sleeve 10 does not need to include four discrete protrusions 15, and can include any suitable number, such as 2, 3, 5, 6, 7, 8, 9 or 10 protrusions 15.

[0038] refer to Figure 5 This illustrates another embodiment of a feeder system 200 including a feeder sleeve 20 mounted on a necked sand core 21. The feeder system 200 and... Figure 1 The feeder system 100 shown is substantially the same, except that at least one protrusion is in the form of a circular edge 25 extending around the entire periphery of the second end 23 of the feeder sleeve 20. The side edges 27 of the edge 25 are square, rather than rounded.

[0039] refer to Figure 6Another embodiment of the feeder system 300 is shown, wherein at least one protrusion is in the form of a square edge 35. The corners 38 of the square edge 35 are rounded. Figure 7 As shown, the minimum distance D3 from the outer surface of the sidewall 34 protruding from the edge 35 of the square to the center of each side of the square and the maximum distance D4 at each corner of the square are shown. D3 is 10% of the maximum diameter D1 of the sidewall 34, and D4 is 35% of the maximum diameter D1 of the sidewall 34. The distance D4 between the sidewall 34 and the corner 38 corresponds to the radius of curvature of the rounded corner.

Claims

1. A feeder system for metal castings, the feeder system comprising a feeder sleeve mounted on a necked sand core, The feeder sleeve has a first end and an opposite second end, a longitudinal axis extending between the first end and the second end, and a continuous sidewall extending generally around the longitudinal axis between the first end and the second end, the sidewall defining a cavity for receiving molten metal during casting. The necked core defines an opening therethrough for connecting the cavity to the casting. The first end of the feeder sleeve is mounted on the necked sand core, and The feeder sleeve includes a plurality of discrete protrusions extending from the outer surface of the sidewall at the second end of the feeder sleeve; and The protrusion extends outward from the sidewall at the second end of the feeder sleeve to a distance of 5% to 35% of the maximum diameter of the sidewall.

2. The feeder system of claim 1, wherein at least one of the plurality of discrete protrusions extends in a direction perpendicular to the longitudinal axis of the feeder sleeve.

3. The feeder system according to claim 1 or claim 2, wherein the sidewall of the feeder sleeve is cylindrical and has a generally circular cross-section.

4. The feeder system according to claim 1 or claim 2, wherein the second end of the feeder sleeve defines an opening therethrough.

5. The feeder system according to claim 1 or claim 2, wherein at least one of the plurality of discrete protrusions is integrally formed with the sidewall.

6. The feeder system according to claim 1 or claim 2, wherein at least one of the plurality of discrete protrusions extends from the second end toward the first end along a maximum height of 4% to 25% of the feeder sleeve, the maximum height being measured in the direction of the longitudinal axis.

7. The feeder system of claim 1, wherein at least one of the plurality of discrete protrusions comprises at least 2, 3, 4, 5, 6, 7, 8, 9 or 10 discrete protrusions.

8. The feeder system of claim 7, wherein at least one of the plurality of discrete protrusions comprises three or four discrete protrusions.

9. The feeder system of claim 1, wherein each protrusion extends 3% to 25% of the circumference of the sidewall at the second end of the feeder sleeve.

10. The feeder system of claim 1, wherein the distance between the centers of adjacent protrusions is 5% to 50% of the circumference of the sidewall at the second end of the feeder sleeve.

11. The feeder system of claim 1, wherein at least one of the plurality of discrete protrusions has a cross-section that is semi-circular, quarter-circular, wedge-shaped, or square.

12. The feeder system of claim 1, wherein the protrusion is arranged in a scalloped configuration around the periphery of the second end of the feeder sleeve.

13. The feeder system of claim 1, wherein at least one of the plurality of discrete protrusions is an annular edge extending around the entire periphery of the second end of the feeder sleeve.

14. The feeder system of claim 13, wherein the annular edge is circular.

15. The feeder system of claim 13, wherein the annular edge has a polygonal cross-section, the polygon having at least three sides.

16. The feeder system of claim 15, wherein the annular edge has a square cross-section.

17. The feeder system of claim 15 or claim 16, wherein the corners of the polygon are rounded.

18. The feeder system of claim 17, wherein the radius of curvature of the corner is 10% to 100% of the maximum distance the corner of the polygon protrudes outward from the outer surface of the sidewall.

19. A feeder sleeve for use in a feeder system according to any one of the preceding claims, the feeder sleeve having a first end and an opposite second end, a longitudinal axis extending between the first end and the second end, and a continuous sidewall extending substantially around the longitudinal axis between the first end and the second end, the sidewall defining a cavity for receiving molten metal during casting. The first end of the feeder sleeve is configured for mounting on the necked sand core, and The feeder sleeve includes a plurality of discrete protrusions extending perpendicularly to the longitudinal axis from the outer surface of the sidewall at the second end of the feeder sleeve; and The protrusion extends outward from the sidewall at the second end of the feeder sleeve to a distance of 5% to 35% of the maximum diameter of the sidewall.

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