Feeder system

Abstract

This invention relates to a feeder system used in metal casting operations using a casting mold, and a feeder sleeve and a necking core used in the feeder system. A feeder system for metal casting is provided, comprising a feeder sleeve mounted on a necking core, the feeder sleeve having a first end and an opposite second end, a longitudinal axis extending between the first and second ends, and a continuous sidewall extending generally around the longitudinal axis between the first and second ends, the sidewall defining a cavity for receiving molten metal during casting, and the necking core defining an opening through the necking core for connecting the cavity to a casting, wherein the first end of the feeder sleeve includes a base mounted on the necking core, and the second end of the feeder sleeve includes a flat top portion and a curved or chamfered portion extending around the periphery of the top portion for connecting the sidewall to the top portion.

Description

Technical Field

[0001] The present invention relates to a feeder system used in metal casting operations using a casting mold, and a feeder sleeve and a necking sand core used 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. A casting mold is typically created by compacting a mixture of sand and binder around a first mold within a sand box, allowing the sand mixture to solidify and harden, and then removing the mold to leave one half of the mold cavity. This process is repeated with a second mold that defines a second half of the mold cavity, and the two halves of the mold (called the upper and lower mold boxes) are then assembled to form the complete mold that defines the full mold cavity. Although molds formed in this way can be used multiple times, they eventually fail or the mold shape may erode, at which point the mold is destroyed and the sand is recycled and repaired for reuse in new molds. However, with this type of mold, it is difficult to recycle the sand and separate it from the binder material at the end of its service life.

[0003] In another casting process known as vacuum mold casting or the "V-process," a mold is made using dry sand without any binder, and its shape is maintained by the force applied by a vacuum. In the V-process, the mold casting includes micropores to allow for vacuum suction. A first plastic film is pulled onto the mold casting and adhered to it via suction. A special sand box, also equipped with a suction system, is placed around the mold casting and filled with dry sand, which is then compacted. The top side of the sand box is covered by a second plastic sealing film, and suction is applied through the sand box, causing the first and second plastic films (at the bottom and top, respectively) to adhere to the molding sand, sealing the sand within the sand box. The vacuum through the mold is then closed and the mold released, while a vacuum is continuously applied through the sand box to keep the sand compacted and maintain the shape of the mold cavity left by the mold. The upper and lower mold boxes, formed in this way, are assembled to form a complete mold cavity, while suction is still applied to maintain the shape of the sand, and molten metal is poured into this cavity. Once the metal casting has cooled and solidified, the molding sand can be easily restored to its original loose state and recovered for future use by simply closing the vacuum.

[0004] In most metal casting processes, metal shrinks during solidification, resulting in shrinkage cavities, which in turn cause unacceptable defects in the final casting. This is a well-known problem in the foundry industry and is addressed by using feeder sleeves or risers integrally molded into the mold. Each feeder sleeve provides an additional (usually closed) volume or cavity communicating with the mold cavity so that molten metal can enter the feeder sleeve from the mold cavity during casting. During casting solidification, the molten metal in the feeder sleeve flows back into the mold cavity to compensate for the casting's shrinkage. After the casting solidifies and the molding sand is removed, unwanted residual metal in the feeder sleeve cavity remains attached to the casting and must be removed. To facilitate the removal of residual metal, in a design often referred to as a necking sleeve, the feeder sleeve cavity can be tapered toward its base (i.e., the end of the feeder sleeve closest to the mold cavity). When a sharp impact is applied to the residual metal, it separates at the weakest point, closer to the mold (a process often referred to as "knock-off"). A smaller coverage area on the casting is also desirable to allow the feeder sleeve to be positioned in areas where entry into the casting may be restricted by adjacent features.

[0005] Although feeder sleeves can be applied directly to the surface of the casting mold cavity, they are typically used in conjunction with necking cores. A conventional necking core is simply a plate or disc of refractory material (typically a resin-bonded core, ceramic core, or feeder sleeve material) with a hole penetrating it between the mold cavity and the feeder sleeve. The diameter of the hole through the necking core is designed to be smaller than the diameter of the feeder sleeve's internal cavity (which is not necessarily conical) to allow for knock-off near the casting surface. Recently developed necking cores (such as those described in Foseco PCT applications No. WO2016 / 034872, No. WO2017 / 025702, and No. WO2016 / 166497) can be in the form of a metal tubular structure with a hole penetrating it.

[0006] During the V-process, before the first plastic film is applied to the mold, the feeder is placed on a boss or pin on the mold. Typically, the feeder is placed on the mold as a pre-forming system, where a necked core is attached to the base of the feeder sleeve, for example, by adhesive. However, film bridges may sometimes form between adjacent feeder sleeves. Furthermore, any sharp edges at the top portion of the feeder sleeve may potentially tear the plastic film as it is pulled onto the mold and feeder sleeves.

[0007] This invention was made in consideration of these problems. Summary of the Invention

[0008] According to a first aspect of the invention, a feeder system for metal casting is provided, 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 and second ends, and a continuous sidewall extending substantially around the longitudinal axis between the first and second ends. The sidewall of the feeder sleeve defines a cavity for receiving molten metal during casting, and the necked sand core defines an opening through the necked sand core for connecting the cavity to a casting. The first end of the feeder sleeve includes a base portion mounted on the necked sand core. The second end of the feeder sleeve includes a flat top portion and a curved or chamfered portion extending around the periphery of the top portion for connecting the sidewall and the top portion of the feeder sleeve.

[0009] Conventional feeder sleeves tend to be square at the top, with an approximately 90° bend between the sleeve's sidewalls and top portion, resulting in a relatively sharp edge at the top of the sleeve. In the feeder system of the present invention, the curved or chamfered portion improves upon the sharp edge at the top of the conventional feeder sleeve and reduces the risk of tearing the plastic film when pulling it across the mold during V-process die formation. In embodiments where the feeder sleeve includes a chamfered portion, this is achieved by effectively creating two edges between the sleeve's sidewalls and top portion, each with a significantly smaller bend angle than 90°, which are not as sharp as a conventional single edge with a 90° bend angle. In embodiments where the feeder sleeve includes a curved portion, any hard edges between the sleeve's sidewalls and top portion are completely eliminated.

[0010] In some embodiments, the sidewalls of the feeder sleeve are cylindrical. The cross-sectional shape of the cylinder can be generally circular, elliptical, or oblong. In some embodiments, the diameter of the cylinder is generally constant from the first end to the second end. In other embodiments, the diameter of the feeder sleeve at the first end can be larger than the diameter at the second end, and vice versa. In some embodiments, the sidewalls of the feeder sleeve are generally cylindrical, with a truncated conical portion positioned toward the first end of the feeder sleeve, the truncated conical portion tapering toward the necked sand core.

[0011] In one embodiment, the base portion at the first end of the feeder sleeve extends substantially perpendicular to the longitudinal axis of the feeder sleeve (i.e., at an angle of approximately 90° relative to the longitudinal axis of the feeder sleeve). Alternatively, the base portion may be inclined at an angle relative to the longitudinal axis of the feeder sleeve such that a sidewall on one side of the feeder sleeve is shorter than a sidewall on the opposite side of the feeder sleeve. In one embodiment, the base portion extends with an inclination angle of at least 30°, 35°, 40°, 50°, 60°, 70°, 80°, or 85° relative to the longitudinal axis of the feeder sleeve. In another embodiment, the base portion extends with an inclination angle of no greater than 88°, 85°, 80°, 70°, 60°, 50°, 40°, or 35° relative to the longitudinal axis of the feeder sleeve. In yet another embodiment, the base portion extends with an inclination angle of 30° to 88°, 40° to 85°, or 50° to 80° relative to the longitudinal axis of the feeder sleeve. It is understood that the necked sand core, on which the feeder sleeve is mounted, will extend in the same direction as the base portion of the feeder sleeve or at the same angle of inclination as the base portion of the feeder sleeve. In cases where the feeder system is located on an angled portion of the casting, an inclined base portion and a necked sand core are desirable.

[0012] In embodiments, the necked core is a conventional plate-shaped or disc-shaped necked core. Alternatively, the necked core may include a flat base defining a hole through the core and an annular raised sidewall extending around the outer periphery of the base. In embodiments, the raised sidewall has a lower surface and an upper surface opposite to the lower surface, the lower surface being attached to or integrally formed with the flat base, wherein an inner edge and an oppositely disposed outer edge extend between the upper and lower surfaces. In embodiments, the height of the raised sidewall is at least 1%, 2%, 5%, 10%, or 15% of the maximum height of the feeder sleeve, wherein the height of the raised sidewall is measured from the lower surface to the upper surface, and the maximum height of the feeder sleeve is measured from a first end to a second end. In embodiments, the height of the raised sidewall is not greater than 15%, 10%, 5%, 2%, or 1% of the maximum height of the feeder sleeve. In embodiments, the height of the raised sidewall is 1%-15%, 2%-10%, or 5-10% of the maximum height of the feeder sleeve. It should be understood that in embodiments where the base portion of the feeder sleeve is inclined relative to the longitudinal axis, the maximum height of the feeder sleeve is the maximum distance between the first end and the second end, i.e., at the position where the height of the sidewall of the feeder sleeve is the maximum.

[0013] Providing a necked core with raised sidewalls allows the feeder system to be applied to the mold as a two-part component when needed. In this two-part application, the necked core is first positioned on the mold, then a first plastic film is pulled onto both the mold and the necked core, and then the feeder sleeve is assembled with the necked core on the plastic film. This prevents the plastic film from bridging between the feeder sleeves, as the film is not pulled onto the sleeves themselves. During casting, the plastic film between the necked core and the feeder sleeve is easily burned off by the molten metal without interfering with the casting process.

[0014] In an embodiment, the necked core also includes a ridge or boss projecting from the upper surface of the raised sidewall in a direction away from the flat base. This boss allows the feeder sleeve to be properly aligned and securely mounted on the necked core during the assembly of the feeder system. In an embodiment, the boss extends completely or partially around the outer periphery of the inner edge of the raised sidewall. The boss may extend around at least 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the outer periphery of the inner edge. The boss may extend around no more than 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of the outer periphery of the inner edge. In an embodiment, the boss extends around approximately 25%–100% or 25%–50% of the outer periphery of the inner edge.

[0015] It should be understood that the first end of the feeder sleeve is suitably configured to be mounted onto the necked core during assembly of the feeder system. For example, in embodiments where the necked core includes raised sidewalls and bosses extending around the inner edges of the raised sidewalls, the sidewalls of the feeder sleeve may have a thickness corresponding to the remaining width of the upper surface of the raised sidewalls excluding the width of the bosses, such that the sidewalls of the feeder sleeve fit snugly against the bosses. Alternatively, the sidewall at the first end of the feeder sleeve may include a cutout or groove configured to receive the bosses on the necked core.

[0016] In one embodiment, the flat top portion is centered at the second end. Preferably, the top portion extends perpendicular to the longitudinal axis of the feeder sleeve.

[0017] Typically, the shape of the top portion can correspond to the cross-sectional shape of the sidewall of the feeder sleeve. For example, in embodiments where the sidewall of the feeder sleeve has a generally circular cross-sectional shape, the top portion can be generally circular; or in embodiments where the sidewall has a generally oblong cross-sectional shape, the top portion can be generally oblong. In embodiments, the top portion has a minimum diameter of at least 25%, 30%, 40%, 50%, 60%, 70%, 80%, or 85% of the minimum diameter of the sidewall of the feeder sleeve. In embodiments, the top portion has a minimum diameter not greater than 90%, 85%, 80%, 70%, 60%, 50%, 40%, or 30% of the minimum diameter of the sidewall. In embodiments, the top portion has a minimum diameter of 25%-90%, 30%-80%, or 40%-70% of the minimum diameter of the sidewall of the feeder sleeve.

[0018] In an embodiment, the top portion of the feeder sleeve includes an opening extending through the top portion. This opening may be located at the center of the top portion. Alternatively, the opening may be offset from the center of the top portion. The shape of the opening in the top portion may correspond to the shape of the top portion. For example, if the top portion is circular, the opening may also be circular, or if the top portion is oblong, the opening may also be oblong. However, the shape of the opening does not necessarily have to correspond to the shape of the top portion (e.g., if the top portion is oblong, the opening may be circular). The area of ​​the opening relative to the top portion can be of any size. In an embodiment, the opening has a minimum diameter of at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% of the minimum diameter of the top portion. In an embodiment, the opening has a minimum diameter not greater than 95%, 90%, 80%, 70%, 60%, 50%, 40%, or 30% of the minimum diameter of the top portion. In embodiments, the minimum diameter of the hole is 20%-100% or 40%-90% of the minimum diameter of the top portion. Preferably, the diameter of the hole is smaller than the diameter of the top portion, such that for manufacturing purposes, there is a certain amount of top portion surrounding the entire periphery of the hole. However, it should be understood that in some embodiments, the minimum diameter of the hole may be 100% of the minimum diameter of the top portion, such that the top portion is entirely composed of the hole.

[0019] In embodiments where the second end of the feeder sleeve includes a chamfered portion, the chamfered portion may extend from the sidewall at an angle of at least 10°, 20°, 30°, 40°, 50°, or 60° relative to the longitudinal axis of the feeder sleeve. The chamfered portion may extend from the sidewall at an angle not greater than 70°, 60°, 50°, 40°, 30°, or 20° relative to the longitudinal axis of the feeder sleeve. In embodiments, the chamfered portion extends from the sidewall at an angle of 10%-70°, 20%-60°, or 30%-50° relative to the longitudinal axis of the feeder sleeve. The chamfered portion may extend over a minimum distance measured between the sidewall and the top portion, which is at least 10%, 20%, 30%, 50%, 75%, 100%, or 125% of the minimum diameter of the sidewall. The chamfered portion may extend to a minimum distance not exceeding 150%, 125%, 100%, 75%, 50%, 30%, or 20% of the minimum diameter of the sidewall. In embodiments, the chamfered portion extends to a minimum distance of 10%-150%, 20%-100%, or 20-50% of the minimum diameter of the sidewall.

[0020] In embodiments where the second end of the feeder sleeve includes a bent portion, the radius of curvature of the bent portion can be at least 2 mm, 5 mm, 10 mm, 20 mm, 30 mm, 50 mm, 75 mm, or 90 mm. The radius of curvature of the bent portion can be no greater than 100 mm, 90 mm, 75 mm, 50 mm, 30 mm, 20 mm, 10 mm, or 5 mm. In embodiments, the radius of curvature of the bent portion is 2-100 mm, 5-75 mm, or 10-50 mm. It should be understood that the precise radius of curvature will depend on the overall dimensions of the feeder sleeve, and if the feeder is exceptionally large, the precise radius of curvature can be greater than these values.

[0021] In an embodiment, the feeder sleeve may include two or more components assembled together by any suitable mechanism (e.g., adhesive, tongue and groove, etc.). One of the components may include a top portion and a bent or chamfered portion, while the other component may include the base portion of the feeder sleeve.

[0022] According to a second aspect of the invention, a feeder system for metal casting is provided, 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 and second ends, and a continuous sidewall extending substantially around the longitudinal axis between the first and second ends. The sidewall of the feeder sleeve defines a cavity for receiving molten metal during casting. The first end of the feeder sleeve includes a base portion mounted on the necked sand core. The necked sand core includes a flat base defining a hole through the necked sand core and an annular raised sidewall extending around the outer periphery of the flat base. The raised sidewall has a lower surface and an upper surface opposite to the lower surface, the lower surface being connected to or integrally formed with the flat base. The necked sand core also includes a ridge or boss projecting from the upper surface of the raised sidewall in a direction away from the flat base, the ridge or boss being configured to engage with the base portion of the feeder sleeve.

[0023] As discussed above regarding the first aspect, providing a necked core with raised sidewalls allows the feeder sleeve to be assembled onto the necked core after the first plastic film has been pulled onto the mold casting, thereby preventing plastic film bridging between adjacent feeder sleeves.

[0024] In one embodiment, the second end of the feeder sleeve includes a flat top portion and a curved or chamfered portion extending around the periphery of the top portion, the curved or chamfered portion serving to connect the sidewall and the top portion of the feeder sleeve. Alternatively, the second end of the feeder sleeve may consist only of a flat top portion directly connected to the sidewall at a 90° angle.

[0025] The invention also relates to a feeder sleeve and necking core used in a feeder system according to embodiments of the first and second aspects.

[0026] According to a third aspect of the invention, a feeder sleeve for 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 sand core, and the second end of the feeder sleeve including a flat top portion and a curved or chamfered portion extending around the periphery of the top portion, the curved or chamfered portion being used to connect the sidewall of the feeder sleeve to the top portion.

[0027] According to a fourth aspect of the invention, a necked sand core for metal casting is provided, the necked sand core including a flat base defining a hole through the necked sand core and an annular raised sidewall extending around the outer periphery of the flat base, the raised sidewall including a lower surface attached to or integrally formed with the flat base and an upper surface opposite to the lower surface, the necked sand core also including a ridge or boss projecting from the upper surface of the raised sidewall in a direction away from the flat base, the ridge or boss being configured to engage with a base portion of a feeder sleeve.

[0028] The features described above regarding the embodiments of the first aspect can also be applied to the embodiments of the second, third, and fourth aspects. Unless any technical incompatibility exists, all combinations of aspects of the invention should be considered. Attached Figure Description

[0029] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0030] Figures 1 to 3 This is a schematic diagram of a feeder system according to an embodiment of the present invention;

[0031] Figure 4 yes Figures 1 to 3 A cross-sectional view of the feeder system shown.

[0032] Figures 5 to 7 These are schematic diagrams of feeder systems according to different embodiments of the present invention;

[0033] Figure 8 yes Figures 5 to 7 A cross-sectional view of the feeder system shown.

[0034] Figure 9 This is a schematic diagram of a feeder system according to another embodiment of the present invention;

[0035] Figure 10 yes Figure 9 A plan view of the feeder system shown.

[0036] Figure 11 This is a schematic diagram of an embodiment of a necked sand core used in conjunction with an embodiment of the feeder system of the present invention; and

[0037] Figure 12 This is a schematic diagram of another embodiment of a necked sand core used in conjunction with an embodiment of the feeder system of the present invention. Detailed Implementation

[0038] Reference Figures 1 to 4The diagram illustrates a feeder system 100 comprising a feeder sleeve 10 mounted on a necked sand core 11, the feeder sleeve 10 having a first end 12 and an opposite second end 13, wherein a longitudinal axis A extends between the first end 12 and the second end 13. A continuous sidewall 14 extends generally in a cylindrical shape around the longitudinal axis A, thereby defining a cavity therein for receiving molten metal. The diameter D1 of the sidewall 14 is constant from the first end 12 to the second end 13 of the feeder sleeve 10.

[0039] The second end 13 of the feeder sleeve 10 includes a centrally located, flat top portion 16 extending perpendicularly to the longitudinal axis A. The second end 13 also includes a curved portion 15 connecting the sidewall 14 of the feeder sleeve and the top portion 16. The radius of curvature of the curved portion 15 is 28.5 mm. The top portion 16 is circular and has a centrally located hole 17 extending through it, the cross-section of which is also generally circular. The diameter D2 of the top portion 16 is 50% of the diameter D1 of the sidewall of the feeder sleeve, and the diameter D3 of the hole 17 is smaller than the diameter D2 of the top portion 16, such that a portion of the top portion 16 extends around the entire periphery of the hole 17.

[0040] The first end 12 of the feeder sleeve 10 is mounted on the necked sand core 11 and is inclined at an angle α of 70° relative to the longitudinal axis, such that the sidewall 14 is shorter on one side of the feeder sleeve 10 than on the opposite side. The necked sand core 11 includes a flat base 110 and a raised sidewall 111 extending around the outer periphery of the flat base 110. Figure 4 (Best shown in the diagram). The flat base 110 is generally circular and includes a centrally located hole 112 extending through the base. The raised sidewall 111 has a lower surface 113 that communicates with and is integrally formed with the flat base 110 and an upper surface 114 opposite to the flat base 110, wherein an inner edge 115 and an oppositely disposed outer edge 116 extend between the lower surface 113 and the upper surface 114. The height H2 of the raised sidewall 111, measured from the lower surface 113 to the upper surface 114, is 6.25% of the maximum height H1 of the feeder sleeve 10 at the point where the height of the sidewall 14 is maximum, measured from the first end 12 to the second end 13.

[0041] The necked core 11 also includes a boss 117 projecting from the inner edge of the upper surface 114 of the raised sidewall 111. The boss 117 extends approximately 25% of the outer periphery of the inner edge 115. The base of the sidewall 14 of the feeder sleeve 10 has a thickness T1 such that the base of the sidewall 14 abuts against the boss 117, the thickness T1 corresponding to the remaining area of ​​the upper surface 114 of the raised sidewall 111 excluding the boss 117.

[0042] Reference Figures 5 to 8This illustrates another embodiment of a feeder system 200 according to the invention. The feeder system 200 includes a feeder sleeve 20 mounted on a necked sand core 21. The feeder sleeve 20 has a first end 22 and an opposite second end 23, wherein a longitudinal axis B extends between the first end 22 and the second end 23. A continuous sidewall 24 extends generally about the longitudinal axis B and is generally cylindrical, thereby defining a cavity therein for receiving molten metal. The diameter of the sidewall 24 at the second end 23 of the feeder sleeve 20 is slightly smaller than the diameter at the first end 22, such that the sidewall 24 has a minimum diameter D4 at the second end 23 of the feeder sleeve.

[0043] The second end 23 of the feeder sleeve 20 includes a centrally located, flat top portion 26 extending perpendicularly to the longitudinal axis B. The second end 23 also includes a chamfered portion 25 connecting the sidewall 24 of the feeder sleeve and the top portion 26. The chamfered portion 25 is inclined at an angle β of 50° relative to the longitudinal axis B and extends a distance W1 equal to 24% of the minimum diameter D4 of the sidewall 24. The top portion 26 is circular and has a centrally located hole 27 extending through it, the hole also having a generally circular cross-section. The diameter D5 of the top portion 26 is 63% of the minimum diameter D4 of the sidewall of the feeder sleeve, and the diameter D6 of the hole 27 is smaller than the diameter D5 of the top portion 26, such that a portion of the top portion 26 extends around the entire periphery of the hole 27.

[0044] The first end 22 of the feeder sleeve 20 is mounted on the necked sand core 21. The first end 22 of the feeder sleeve 20 extends perpendicular to the longitudinal axis B so that the sidewalls 24 have a uniform height. The necked sand core 21 includes a flat base 210 and raised sidewalls 211 extending around the outer periphery of the flat base 210. Figure 8 (Best shown in the diagram). The flat base 210 is generally circular and includes a centrally located hole 212 extending through the base. The raised sidewall 211 has a lower surface 213 that communicates with and is integrally formed with the flat base 210 and an upper surface 214 opposite to the flat base 210, wherein an inner edge 215 and an oppositely disposed outer edge 216 extend between the lower surface 213 and the upper surface 214. The height H4 of the raised sidewall 211, measured from the lower surface 213 to the upper surface 214, is 6% of the height H3 of the feeder sleeve 20, measured from the first end 22 to the second end 23.

[0045] The necked core 21 also includes a boss 217 projecting from the inner edge of the upper surface 214 of the raised sidewall 211. The boss 217 extends around the entire outer periphery of the inner edge 215. The base of the sidewall 24 of the feeder sleeve 20 has a thickness T2 such that the base of the sidewall 24 abuts against the boss 217, and this thickness T2 corresponds to the remaining area of ​​the upper surface 214 of the raised sidewall 211 excluding the boss 217.

[0046] Reference Figures 9 to 10 This illustrates another embodiment of a feeder system 300 according to the invention. The feeder system 300 includes a feeder sleeve 30 mounted on a necked sand core 31. The feeder sleeve 30 has a first end 32 and an opposite second end 33, wherein a longitudinal axis (not shown) extends between the first end 32 and the second end 33. Continuous sidewalls 34 extend generally around the longitudinal axis in an elongated oval cross-sectional shape, thereby defining a cavity therein for receiving molten metal.

[0047] The first end 32 of the feeder sleeve 30 is mounted on the necked sand core 31. The first end 32 of the feeder sleeve 30 extends perpendicular to the longitudinal axis, such that the sidewalls 34 have a uniform height. The necked sand core 31 includes a flat base (not shown) and raised sidewalls 311 extending around the outer periphery of the flat base. The flat base is generally oblong and includes a centrally located hole (not shown) extending through the base.

[0048] The second end 33 of the feeder sleeve 30 includes a centrally located, flat top portion 36 extending perpendicular to the longitudinal axis. The second end 33 also includes a curved portion 35 connecting the sidewall 34 of the feeder sleeve 30 and the top portion 36. The top portion 36 is oblong and has a centrally located hole 37 extending through the top portion, the hole also having an oblong cross-section.

[0049] like Figure 10 As shown, the sidewall 34 has a minimum diameter D7 between the long sides of the oblong cross-section and a maximum diameter D8 between the short sides of the oblong cross-section. The top portion 36 of the oblong also has a minimum diameter D9 between the long sides and a maximum diameter D8 between the short sides. 10 The minimum diameter D9 of the top portion 36 is approximately 40% of the minimum diameter D7 of the sidewall 34. The diameter of the hole 37 is smaller than the diameter of the top portion 36, such that a portion of the top portion 36 extends around the entire periphery of the hole 37.

[0050] Reference Figure 11This illustration shows an embodiment of a necked core 400 used in a feeder system according to an embodiment of the present invention. The necked core 400 includes a flat base 410 and a raised sidewall 411 extending around the outer periphery of the flat base 410. The flat base 410 is generally circular and includes a centrally located hole 412 extending through the base. The raised sidewall 411 has a lower surface (not shown) communicating with and integrally formed with the flat base 410 and an upper surface 414 opposite to the flat base 410, wherein an inner edge 415 and an oppositely disposed outer edge 416 extend between the lower surface 413 and the upper surface 414. The necked core 400 also includes a boss 417 projecting from the inner edge side of the upper surface 414 of the raised sidewall 411. The boss 417 extends about 25% of the outer periphery of the inner edge 215.

[0051] Reference Figure 12 This illustrates another embodiment of a necked core 500 used in a feeder system according to an embodiment of the present invention. The necked core 500 includes components with... Figure 11 The necked core 400 shown has essentially the same features as the one described, except that the planar base 510 is oblong instead of circular and the boss 517 extends around the entire periphery of the inner edge side of the upper surface 514. The cross-section of the hole 512 extending through the flat base 510 is also oblong.

Claims

1. A vacuum process mold comprising a feeder system for metal casting, said feeder system including 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 about the longitudinal axis between the first end and the second end, the sidewall defining a cavity for receiving molten metal during casting. The necking core defines an opening through which the cavity is connected to the casting. in, The first end of the feeder sleeve includes a base portion mounted on the necked sand core; and The second end of the feeder sleeve includes a flat top portion and a curved portion extending around the periphery of the top portion, the curved portion being used to connect the sidewall and the top portion, wherein the feeder system is mounted on the vacuum process mold via the necked sand core.

2. The vacuum process mold according to claim 1, wherein, The sidewall of the feeder sleeve is cylindrical, and the cross-sectional shape of the cylinder is circular, elliptical, or oblong.

3. The vacuum process mold according to claim 1 or 2, wherein, The base portion and the necked sand core extend at an angle of 2°-100° relative to the longitudinal axis of the feeder sleeve.

4. The vacuum process mold according to claim 1 or 2, wherein, The base portion and the necked sand core extend perpendicular to the longitudinal axis of the feeder sleeve.

5. The vacuum process mold according to claim 1, wherein, The necked core includes a flat base and raised sidewalls extending around the outer periphery of the flat base.

6. The vacuum process mold according to claim 5, wherein, The height of the raised sidewall is 1% - 15% of the height of the feeder sleeve.

7. The vacuum process mold according to claim 5 or 6, wherein, The necked core further includes a boss protruding from the upper surface of the raised sidewall.

8. The vacuum process mold according to claim 7, wherein, The boss protrudes partially or completely around the outer periphery of the inner edge of the raised sidewall.

9. The vacuum process mold according to claim 1 or 2, wherein, The minimum diameter of the top portion is 25% - 90% of the minimum diameter of the sidewall of the feeder sleeve.

10. The vacuum process mold according to claim 1 or 2, wherein, The top portion includes an opening that extends through the top portion.

11. The vacuum process mold according to claim 10, wherein, The minimum diameter of the opening extending through the top portion is 20% - 100% of the minimum diameter of the top portion.

12. The vacuum process mold according to claim 1 or 2, wherein, The radius of curvature of the curved portion is 2 mm - 100 mm.

13. The vacuum process mold according to claim 1 or 2, wherein, The sidewall of the feeder sleeve includes two or more components assembled together, wherein one of the components includes the top portion and the curved portion, and wherein the other component includes the base portion.

14. A vacuum process mold, the vacuum process mold comprising a feeder system for metal casting, 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 about the longitudinal axis between the first end and the second end, the sidewall defining a cavity for receiving molten metal during casting. in, The first end of the feeder sleeve includes a base portion mounted on the necked sand core; and The necked core includes: A flat base, which defines a hole penetrating the base, and An annular, raised sidewall extending around the outer periphery of the flat base, the raised sidewall having a lower surface attached to or integrally formed with the flat base and an upper surface opposite to the lower surface, and A ridge or boss protrudes from the upper surface of the raised sidewall in a direction away from the flat base, the ridge or boss being configured to engage with the base portion of the feeder sleeve, wherein the feeder system is mounted on the vacuum process mold via a necked sand core.

15. The vacuum process mold according to claim 14, wherein, The height of the protruding sidewall is 1% to 15% of the height of the feeder sleeve.

16. The vacuum process mold according to claim 14 or 15, wherein, The ridge or boss protrudes partially or completely around the outer periphery of the inner edge of the raised sidewall.

17. The vacuum process mold according to any one of claims 14 to 15, wherein, The second end of the feeder sleeve includes a flat top portion and a chamfered portion extending around the periphery of the top portion, the chamfered portion serving to connect the sidewall and the top portion.

18. A vacuum process mold, the vacuum process mold comprising a feeder system for metal casting, 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 between the first end and the second end around the longitudinal axis, the sidewall defining a cavity for receiving molten metal during casting. The defined opening extending through the necked sand core is used to connect the cavity to the casting. in, The first end of the feeder sleeve includes a base portion mounted on the necked sand core. The second end of the feeder sleeve includes a flat top portion and a chamfered portion extending around the periphery of the top portion, the chamfered portion serving to connect the sidewall and the top portion. The sidewall of the feeder sleeve includes two or more components assembled together, one of the components including the top portion and the chamfered portion, and the other component including the base portion, wherein the feeder system is mounted on a vacuum process mold via a necked sand core.

19. The vacuum process mold according to claim 18, wherein, The chamfered portion extends at an angle of 10°-70° relative to the longitudinal axis of the feeder system.

20. The vacuum process mold according to any one of claims 18 to 19, wherein, The width of the chamfered portion, measured between the sidewall and the top portion, is 10% - 150% of the minimum diameter of the sidewall.

21. The vacuum process mold according to any one of claims 18 to 19, wherein, The sidewall of the feeder sleeve is cylindrical, and the cross-sectional shape of the cylinder is circular, elliptical, or oblong.

22. The vacuum process mold according to any one of claims 18 to 19, wherein, The base portion and the necked sand core extend at an angle of 2° to 100° relative to the longitudinal axis of the feeder sleeve.

23. The vacuum process mold according to any one of claims 18 to 19, wherein, The base portion and the necked sand core extend perpendicular to the longitudinal axis of the feeder sleeve.

24. The vacuum process mold according to any one of claims 18 to 19, wherein, The minimum diameter of the top portion is 25% - 90% of the minimum diameter of the sidewall of the feeder sleeve.

25. The vacuum process mold according to any one of claims 18 to 19, wherein, The top portion includes an opening that extends through the top portion.

26. The vacuum process mold according to claim 25, wherein, The minimum diameter of the opening extending through the top portion is 20% - 100% of the minimum diameter of the top portion.

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