Hybrid mold with improved heat transfer

Abstract

Hybrid mold (10) with improved heat transfer for casting a sand-cast aluminum part (11) of a vehicle, the hybrid cooling comprising: a base (12) comprising an outer wall (14) having a first side (16) and a second side (18) opposite the first side (16), both the first side (16) and the second side (18) extending from a first longitudinal end (20) to an opposite second longitudinal end (22) and along a first lateral end (24) and a second lateral end (26) opposite the first lateral end (24), the outer wall (14) being closed to define a hollow portion (30), the base (12) further comprising a heat transfer fluid in a liquid phase disposed in the hollow portion (30), the heat transfer fluid having a boiling point between 320°C and 400°C at 1 bar for improved heat transfer during casting; and a plurality of crankcase elements (34), each element being disposed on the first side (16) and extending from the first lateral end (24) to the second lateral end (26) of the outer wall (14), each element being parallel to and spaced from a respective adjacent element and defining an open recess (36) extending between adjacent elements from the first lateral end (24) to the second lateral end (26), at least one crankcase element (234) having an internal cavity (240) formed therein and in fluid communication with the hollow portion of the body, the internal cavity (234) containing a heat transfer fluid to enhance heat transfer, wherein the inner cavity (234) of the at least one crankcase element (234) is formed by an outer wall (214) having an inner surface, the inner surface having a surface roughness to increase the surface area for improved heat transfer, wherein the second side of the base (12) comprises a plurality of ribs formed transversely from the first lateral end (24) to the second lateral end (26), each rib being spaced from a respective adjacent rib (440) to define an open portion extending between adjacent ribs (440) from the first lateral end (24) to the second lateral end (26) to enhance heat transfer.

Description

Technical FieldThe present disclosure relates to ingot molds for casting an aluminum sand casting, and more particularly to hybrid ingot molds with improved heat transfer for casting an aluminum sand casting engine block of a vehicle.IntroductionChills are used in casting for cooling during solidification of an aluminum sand casting, such as an aluminum engine block. The chills are placed on the sand casting to aid in heat transfer. In conventional chills, an aluminum sand casting may still have undesirable porosity and dendritic arm spacings from aluminum casting.US 2022 / 0 241 847 A1 discloses a mold package for producing a cast component, such as an engine block. The mold package includes a profiled cooling mold and a mold core assembly disposed thereon that defines a plurality of bulkhead walls of the engine block. The profiled cooling mold has a first cooling mold section which carries a second cooling mold section and a plurality of third cooling mold sections, the second cooling mold section being a semi-cylindrical element. The third cooling form portions are disposed adjacent to the bulkhead walls of the engine block.EP 0 283 622 B1 describes an improvement of methods for handling molten materials at high temperatures. The improvement consists in using a polyorganosiloxane fluid as a cooling medium instead of water. This avoids the risk of damascene infections which may occur when water comes into contact with molten materials.DESCRIPTION OF THE INVENTIONThus, while current ingot molds serve their purpose, there is a need for a new and improved hybrid ingot mold with improved heat transfer for casting aluminum sand castings.This object is achieved by the subject matter according to claim 1.According to an aspect of the present disclosure, a hybrid mold with improved heat transfer is provided for casting a sand cast aluminum part of a vehicle. The hybrid mold includes a base having an outer wall having a first side and a second side opposite the first side. Each of the first side and the second sides extends from a first longitudinal end to an opposite second longitudinal end and along a first lateral end and a second lateral end opposite the first lateral end. In this aspect, the outer wall is closed to define a hollow portion.In addition, the base includes a liquid phase heat transfer fluid disposed within the hollow portion. In this aspect, the heat transfer fluid has a boiling point between 320° Celsius (° C.) and 400° C. at 1 bar for improved heat transfer during casting.The mold further includes a plurality of crankcase elements. Each member is disposed on the first side and extends from the first lateral end to the second lateral end of the outer wall. Moreover, each member is parallel to and spaced from a respective adjacent member that defines an open recess between adjacent members from the first lateral end to the second lateral end.In one embodiment, the outer wall is gray cast iron (Fe) with 2.8 to 3.3 weight percent (wt %) carbon (C), 1.2 to 1.7 wt % silicon (Si), 0.8 to 1.2 wt % manganese (Mn), less than 0.15 wt % phosphorus (P), and less than 0.12 wt % sulfur (S). In another embodiment, the outer wall has a thickness between 5 millimeters (mm) and 50 mm. In this embodiment, the outer wall is gray cast iron with 2.9 to 3.2 weight percent (wt %) carbon (C), 1.3 to 1.6 wt % silicon (Si), 0.9 to 1.1 wt % manganese (Mn), less than 0.15 wt % phosphorus (P) and less than 0.12 wt % sulfur (S).In another embodiment, at least one crankcase member includes an interior cavity formed therein and in fluid communication with the hollow portion of the housing. The inner cavity contains a heat transfer fluid to improve heat transfer. In another embodiment, the interior cavity of the at least one crankcase member is formed by the outer wall having an inner surface. The inner surface has a surface roughness to increase the surface area for improved heat transfer.In another embodiment, the second side of the base includes a plurality of ribs extending from the first lateral end toward the second lateral end. In this embodiment, each fin is spaced from the respective adjacent fin to define an open area that extends between adjacent fins from the first lateral end to the second lateral end to improve heat transfer.In another embodiment, the heat transfer fluid is a liquid phase silicon-based heat transfer fluid. In another embodiment, the heat transfer fluid is a silicon-based heat transfer fluid that includes polydimethylsiloxane.According to another aspect of the present disclosure, a hybrid mold with improved heat transfer is provided for casting an aluminum sand casting engine block of a vehicle. The hybrid mold includes a base having an outer wall having a first side and a second side opposite the first side. Each of the first side and the second sides extends from a first longitudinal end to an opposite second longitudinal end and along a first lateral end and a second lateral end opposite the first lateral end. The outer wall is closed to form a hollow portion.The base further comprises a silicon-based heat transfer fluid in a liquid phase disposed in the hollow portion. The heat transfer fluid has a boiling point between 320° Celsius (° C.) and 400° C. at 1 bar for improved heat transfer during casting. The outer wall consists of grey cast iron with 2.8 to 3.3 wt.% C, 1.2 to 1.7 wt.% Si, 0.8 to 1.2 wt.% Mn, less than 0.15 wt.% P and less than 0.12 wt.% S.In this aspect, the mold further includes a plurality of crankcase members. Each member is disposed on the first side and extends from the first lateral end to the second lateral end of the outer wall. Each member is parallel to and spaced from a respective adjacent member defining an open recess extending between adjacent members from the first lateral end to the second lateral end.In one embodiment, the outer wall has a thickness between 5 millimeters (mm) and 50 mm. In this embodiment, the outer wall is gray cast iron with 2.9 to 3.2 weight percent (wt %) carbon (C), 1.3 to 1.6 wt % silicon (Si), 0.9 to 1.1 wt % manganese (Mn), less than 0.15 wt % phosphorus (P) and less than 0.12 wt % sulfur (S).In another embodiment, at least one crankcase member includes an interior cavity formed therein that is in fluid communication with the hollow portion of the housing. The inner cavity contains a heat transfer fluid to improve heat transfer. In one embodiment, the interior cavity of the at least one crankcase member is formed by the outer wall having an inner surface. The inner surface has a surface roughness to increase the surface area for improved heat transfer.In yet another embodiment, the second side of the base includes a plurality of ribs extending from the first lateral end toward the second lateral end. Each fin is spaced from the respective adjacent fin to define an open area that extends between adjacent fins from the first lateral end to the second lateral end to improve heat transfer. In another embodiment, the heat transfer fluid is a silicone-based heat transfer fluid comprising polydimethylsiloxane.According to yet another aspect of the present disclosure, a hybrid mold with improved heat transfer is provided for casting an aluminum sand casting engine block of a vehicle. In this aspect, the hybrid mold includes a base having an outer wall having a first side and a second side opposite the first side. Each of the first and second sides extends from a first longitudinal end to an opposite second longitudinal end and along a first lateral end and a second lateral end opposite the first lateral end.In this aspect, the outer wall is closed to define a hollow portion. The base further comprises a liquid phase heat transfer fluid disposed within the hollow portion. The heat transfer fluid has a boiling point between 320°C and 400°C at 1 bar for improved heat transfer during casting. The heat transfer fluid is a silicone-based heat transfer fluid comprising polydimethylsiloxane.The mold further comprises a plurality of crankcase members, each member disposed on the first side and extending from the first lateral end to the second lateral end of the outer wall, each member parallel to and spaced from a respective adjacent member and defining an open recess extending between adjacent members from the first lateral end to the second lateral end.In one embodiment, the outer wall is gray cast (Fe) with 2.8 to 3.3 wt % C, 1.2 to 1.7 wt % Si, 0.8 to 1.2 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S. In another embodiment, the outer wall has a thickness between 30 mm and 50 mm, and the outer wall is gray cast with 2.9 to 3.2 wt % C, 1.3 to 1.6 wt % Si, 0.9 to 1.1 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S.In another embodiment, at least one crankcase member includes an interior cavity formed therein and in fluid communication with the hollow portion of the housing. In addition, the interior cavity contains a heat transfer fluid for improved heat transfer.In yet another embodiment, the interior cavity of the at least one crankcase member is formed by an outer wall having an inner surface. The inner surface has a surface roughness to increase the surface area for improved heat transfer. In another embodiment, the second side of the base includes a plurality of ribs extending from the first lateral end to the second lateral end. Moreover, each fin is spaced from a respective adjacent fin to define an open portion that extends between adjacent fins from the first lateral end to the second lateral end to improve heat transfer.Further areas of applicability will become apparent from the description herein. It should be understood that the specification and specific examples are intended to be illustrative only and not to limit the scope of the present disclosure.Brief Description of the DrawingsThe drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. FIG. 1 is a perspective view of a hybrid mold with improved heat transfer in accordance with an embodiment of the present disclosure. FIG. 2 is an end cross-sectional view of the hybrid mold of FIG. 1 taken along lines 2- 2. FIG. 3 is a side cross-sectional view of a conceptual image of the hybrid mold of FIG. 1 having a hollow portion with heat transfer fluid according to an embodiment of the present disclosure. FIG. 4 is a side cross-sectional view of a conceptual image of the hybrid mold of FIG. 1 having an internal cavity with heat transfer fluid in accordance with another embodiment. FIG. 5A is a side cross-sectional view of a conceptual image of the hybrid mold in FIG. 1 having an inner surface with a surface roughness according to another embodiment. FIG. 5B is an enlarged view of the inner surface in circle 5B of FIG. 5A. FIG. 6 is a side cross-sectional view of a conceptual image of the hybrid mold of FIG. 1 with fins formed transversely thereto for improved heat transfer according to another embodiment.Detailed DescriptionThe following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or use.Aspects of the present disclosure provide a hybrid mold having improved heat transfer capability for casting a sand cast aluminum part of a vehicle. The hybrid mold comprises a heat transfer fluid (preferably silicon-based) disposed in a hollow portion thereof. The heat transfer fluid is in a liquid phase to provide improved heat transfer during part solidification.FIGS. 1 and 2 show a hybrid mold 10 with improved heat transfer for casting a sand cast aluminum engine block 11 of a vehicle according to an embodiment of the present disclosure. As shown, the hybrid mold 10 includes a base 12 having an outer wall 14.As shown in FIGS. 1-2, each of the first side 16 and the second side 18 extends from a first longitudinal end 20 to a second longitudinal end 22. In addition, each of the first side 16 and the second side 18 extends along a first lateral end 24 and a second lateral end 26 opposite the first lateral end 24. As seen in FIG. 2, the outer wall 14 is closed to define a hollow portion 30.Referring to FIG. 2, the base 12 further includes a liquid phase heat transfer fluid 32 disposed within the hollow portion 30. In this aspect, the heat transfer fluid 32 has a boiling point between 320° Celsius (° C.) and 400° C. at 1 bar for improved heat transfer during casting. Preferably, the heat transfer fluid 32 is a liquid phase silicon-based heat transfer fluid.More specifically, the heat transfer fluid 32 may be a silicon-based heat transfer fluid including polydimethylsiloxane.As shown in FIGS. 1-2, the mold 10 further includes a plurality of crankcase members 34. each member 34 is disposed on the first side 16 and extends from the first lateral end 24 to the second lateral end 26 of the outer wall 14. As shown, the open recess 36 extends from the first lateral end 24 to the second lateral end 26.In one embodiment, the outer wall 14 is gray cast iron (Fe) having 2.8 to 3.3 weight percent (wt %) carbon (C), 1.2 to 1.7 wt % silicon (Si), 0.8 to 1.2 wt % manganese (Mn), less than 0.15 wt % phosphorus (P), and less than 0.12 wt % sulfur (S).Preferably, the outer wall 14 may have a thickness between 30 millimeters (mm) and 50 mm. In this embodiment, the outer wall is gray cast iron containing 2.9 to 3.2 weight percent (wt %) C, 1.3 to 1.6 wt % Si, 0.9 to 1.1 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S.In addition, the outer wall 14 may have a thickness of more than 50 mm. In this embodiment, the outer wall is made of gray cast iron containing 2.8 to 3.1 wt% C, 1.2 to 1.5 wt% Si, 1.0 to 1.2 wt% Mn, less than 0.15 wt% P, and less than 0.12 wt% S.Additionally, the outer wall 14 may have a thickness of less than 30 mm. In this embodiment, the outer wall is made of gray cast iron containing 3.0 to 3.3 wt% C, 1.4 to 1.7 wt% Si, 0.8 to 1.0 wt% Mn, less than 0.15 wt% P, and less than 0.12 wt% S.FIG. 3 shows a conceptual image of the hybrid mold 10 shown in FIGS. 1-2, in accordance with an embodiment of the present disclosure. The hybrid mold 110 of FIG. 3 includes the same or similar components as the hybrid mold 10 of FIGS. 1-2. For example, the bottom 112, the outer wall 114, the first side 116, the second side 118, the first longitudinal end 120, the second longitudinal end 122, the hollow portion 130, and the heat transfer fluid 132 shown in FIG. 3 correspond to the bottom 12, the outer wall 14, the first side 16, the second side 18, the first longitudinal end 20, the second longitudinal end 22, the hollow portion 30, and the heat transfer fluid 32 shown in FIGS. 1-2, respectively.As shown in FIG. 3, the base 112 of the mold 110 includes the heat transfer fluid 132 in a liquid phase disposed in the hollow portion 130. In this embodiment, the heat transfer fluid 132 has a boiling point between 320° Celsius (° C.) and 400° C. at 1 bar for improved heat transfer during casting. More preferably, the boiling point of the heat transfer fluid is between 340° C. and 360° C. Even more preferably, the boiling point of the heat transfer fluid may be one of 330° C., 340° C., 350° C., 360° C., 370° C., 380° C. and 390° C. In this embodiment, the heat transfer fluid is a liquid phase silicon-based heat transfer fluid. In particular, the heat transfer fluid may be a silicon-based heat transfer fluid including polydimethylsiloxane.In this embodiment, portions of the outer wall 114 may have a thickness of greater than 50 mm and may be composed of gray cast iron (Fe) comprising 2.8 to 3.1 wt % C, 1.2 to 1.5 wt % Si, 1.0 to 1.2 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S. In addition, other portions of the outer wall 114 may have a thickness between 30 mm and 50 mm. As such, the outer wall 114 is gray cast iron with 2.9 to 3.2 wt % C, 1.3 to 1.6 wt % Si, 0.9 to 1.1 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S.FIG. 4 shows a conceptual image of the hybrid mold 10 shown in FIGS. 1-2, in accordance with another embodiment of the present disclosure. The hybrid mold 210 of FIG. 4 includes the same or similar components as the hybrid mold of FIGS. 1-2. For example, the base 212, the outer wall 214, the first side 216, the second side 218, the first longitudinal end 220, the second longitudinal end 222, the hollow portion 230, and the heat transfer fluid 232 illustrated in FIG. 3 correspond to the base 12, the outer wall 14, the first side 16, the second side 18, the first longitudinal end 20, the second longitudinal end 22, the hollow portion 30, and the heat transfer fluid 32 illustrated in FIGS. 1-2, respectively.As shown in FIG. 4, at least one crankcase member 234 (all crankcase members are shown) includes an interior cavity 240 formed therein and in fluid communication with the hollow portion 230 of the base 212. Like the hollow portion 230, the interior cavity 240 also contains a heat transfer fluid 232 for increased heat transfer. Preferably, the heat transfer fluid 232 is a liquid phase silicon-based heat transfer fluid. More specifically, the heat transfer fluid 232 may be a silicon-based heat transfer fluid including polydimethylsiloxane.In this embodiment, a portion of the outer wall 214 may be less than 30 mm thick and may be made of gray cast iron (Fe) comprising 3.0 to 3.3 wt % C, 1.4 to 1.7 wt % Si, 0.8 to 1.0 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S. Moreover, other portions of the outer wall 214 may have a thickness between 30 mm and 50 mm. Thus, the outer wall 214 is gray cast iron with 2.9 to 3.2 wt % C, 1.3 to 1.6 wt % Si, 0.9 to 1.1 wt % Mn, less than 0.15 wt % P and less than 0.12 wt % S.FIG. 5A shows a conceptual image of the hybrid mold 10 shown in FIGS. 1-2, in accordance with another embodiment of the present disclosure. The hybrid mold 310 of FIG. 5A includes the same or similar components as the hybrid mold 10 of FIGS. 1-2. For example, the base 3 12, the outer wall 314, the first side 316, the second side 318, the first longitudinal end 320, the second longitudinal end 322, the hollow portion 330, and the heat transfer fluid 332 illustrated in FIG. 3 correspond to the base 12, the outer wall 14, the first side 16, the second side 18, the first longitudinal end 20, the second longitudinal end 22, the hollow portion 30, and the heat transfer fluid 32 illustrated in FIGS. 1-2, respectively.As shown in FIG. 5A, the interior cavity 340 of the at least one crankcase member is formed by the outer wall 314 having an inner surface 342. As shown in FIGS. 5A-5B, the inner surface 342 has a surface roughness to increase the surface area for improved heat transfer. Preferably, but not necessarily, the inner surface 342 includes peaks 344 and valleys 346 defining an open area 348 between the respective peaks 344 for further improving heat transfer. The inner surface 342 may be provided with other formations to increase the surface area and thereby improve heat transfer without departing from the scope or spirit of the present disclosure.In this embodiment, a portion of the outer wall 314 may be less than 30 mm thick and may be gray cast iron (Fe) comprising 3.0 to 3.3 wt % C, 1.4 to 1.7 wt % Si, 0.8 to 1.0 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S. Thus, the outer wall is gray cast iron with 2.9 to 3.2 wt % C, 1.3 to 1.6 wt % Si, 0.9 to 1.1 wt % Mn, less than 0.15 wt % P and less than 0.12 wt % S.FIG. 6 shows a conceptual image of the hybrid mold 10 shown in FIGS. 1-2, in accordance with another embodiment of the present disclosure. The hybrid mold 410 of FIG. 6 includes the same or similar components of the hybrid mold 10 of FIGS. 1-2. For example, the base 412, the outer wall 414, the first side 416, the second side 418, the first longitudinal end 420, the second longitudinal end 422, the hollow portion 430, and the heat transfer fluid 432 illustrated in FIG. 3 correspond to the base 12, the outer wall 14, the first side 16, the second side 18, the first longitudinal end 20, the second longitudinal end 22, the hollow portion 30, and the heat transfer fluid 32 illustrated in FIGS. 1-2, respectively.As shown in FIG. 6, the second side 418 of the base 412 includes a plurality of ribs 440 that extend from the first lateral end toward the second lateral end. In this embodiment, each fin 440 is spaced from a respective adjacent fin 440 to define an open portion 442 that extends between adjacent fins 440 from the first lateral end to the second lateral end to improve heat transfer.In this embodiment, a portion of the outer wall 414 is less than 30 mm thick and is made of gray cast iron (Fe) with 3.0 to 3.3 wt % C, 1.4 to 1.7 wt % Si, 0.8 to 1.0 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S. In addition, another portion of the outer wall 414 may have a thickness between 30 mm and 50 mm. The outer wall is gray cast iron with 2.9 to 3.2 wt % C, 1.3 to 1.6 wt % Si, 0.9 to 1.1 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S. Moreover, other portions of the outer wall 414 may have a thickness of more than 50 mm and consist of gray cast iron (Fe) comprising 2.8 to 3.1 wt % C, 1.2 to 1.5 wt % Si, 1.0 to 1.2 wt % Mn, less than 0.15 wt % P, and less than 0.12 wt % S.It should be appreciated that the hybrid mold may be used for various cast parts of aluminum sand casting of a vehicle, such as a gearbox block, a differential block, or other suitable vehicle part, without sacrificing the spirit or scope of the present disclosure.The description of the present disclosure is merely exemplary in nature, and variations that do not depart from the gist of the present disclosure are intended to fall within the scope of the present disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure.

Claims

A hybrid improved heat transfer chill (10) for casting a sand cast aluminum part (11) of a vehicle, the hybrid cooling comprising: a base (12) comprising an outer wall (14) having a first side (16) and a second side (18) opposite the first side (16), wherein both the first side (16) and the second side (18) extend from a first longitudinal end (20) to an opposite second longitudinal end (22) and along a first lateral end (24) and a second lateral end (26) opposite the first lateral end (24), the outer wall (14) being closed to define a hollow portion (30), the base (12) further comprising a liquid phase heat transfer fluid disposed within the hollow portion (30), wherein the heat transfer fluid has a boiling point between 320°C and 400°C at 1 bar for improved heat transfer during casting; and a plurality of crankcase members (34), each member disposed on the first side (16) and extending from the first lateral end (24) to the second lateral end (26) of the outer wall (14), each member being parallel to and spaced from a respective adjacent member and defining an open recess (36) extending between adjacent members from the first lateral end (24) to the second lateral end (26), at least one crankcase member (234) having an interior cavity (240) formed therein and in fluid communication with the hollow portion of the body, the interior cavity (234) containing a heat transfer fluid to increase heat transfer, wherein the interior cavity (234) of the at least one crankcase member (234) is formed by an outer wall (214) having an inner surface, the inner surface having a surface roughness to increase the surface area for improved heat transfer, wherein the second side of the base (12) comprises a plurality of ribs formed transversely from the first lateral end (24) to the second lateral end (26), each rib being spaced from a respective adjacent rib (440) to define an open portion extending between adjacent ribs (440) from the first lateral end (24) to the second lateral end (26) to improve heat transfer.The mold (10) of claim 1, wherein the outer wall (14) is comprised of gray cast iron (Fe) comprising 2.8 to 3.3 weight percent, weight %, carbon (C), 1.2 to 1.7 weight % silicon (Si), 0.8 to 1.2 weight % manganese (Mn), less than 0.15 weight % phosphorus (P), and less than 0.12 weight % sulfur (S).The mold (10) of claim 1, wherein the outer wall (14) has a thickness between 5 millimeters (mm) and 50 mm, and wherein the outer wall (14) is comprised of gray cast iron comprising 2.9 to 3.2 weight percent, wt%, carbon (C), 1.3 to 1.6 wt% silicon (Si), 0.9 to 1.1 wt% manganese (Mn), less than 0.15 wt% phosphorus (P), and less than 0.12 wt% sulfur (S).The mold (10) of claim 1, wherein the heat transfer fluid is a liquid phase silicon-based heat transfer fluid.The mold (10) of claim 1, wherein the heat transfer fluid is a silicone-based heat transfer fluid comprising polydimethylsiloxane.

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