Cmi International, Inc.

John W Kuhn

Richard J Wylie

Thomas E Prucha

Karl D Voss

Gary F Ruff

Jerome D VanAelst

A decomposable casting core (56a, 56b) is formed in-situ with a sleeve-like liner member (64) and the assembly mounted within the mold cavity (24) of a cylinder block casting mold (22) for lining piston cylinder chambers (62a, 62b) of a cylinder block (26) cast within the mold (22). The liner member (64) is formed with an inner annular recess (80) which receives a corresponding annular projection (76) of the core (56a, 56b) for preventing the liner (64) from sliding axially on the core (56a, 56b) during casting.

Casting core and method for cast-in-place attachment of a cylinder liner

A method for metallurgically bonding cylinder liners (12, 12') within a cylinder block 14 of an internal combustion engine. The liners (12, 12') are cleaned (16) and their outer surfaces coated (18) with a low melting point cooling material (20) such as molten zinc forming a metallurgical bond therebetween. The coating (20) is allowed to solidify forming an outer oxidized layer (24) on the coating (20). The oxidized layer (24) is subsequently removed to expose an unoxidized outer surface (26) of the coating (20). The coated liners (12, 12') are then disposed within a casting mold and molten aluminum-based cylinder block material (36) is poured into the mold and about the coated liners (12, 12'). The molten cylinder block material (36) remelts the coating (20) on the liners (12, 12') and causes the coating to further alloy with the cylinder block material (36), whereupon cooling the cylinder liners (12, 12') are metallurgically bonded to the cylinder block (14).

Method for metallurgically bonding cylinder liners to a cylinder block

A method of eliminating solidification shrinkage porosity defects in cast metal articles includes disposing an expanded polystyrene chill (36) within a preformed mold cavity (26) and thereafter introducing molten metal into the cavity (26) and vaporizing the chill member (36), whereby the heat of vaporization rapidly cools a localized region of the molten metal adjacent the chill member and accelerates solidification thereof enabling remote still-molten metal to feed solidification shrinkage in this region and prevent the formation of porosity defects that would otherwise result.

Method of eliminating shrinkage porosity defects in the formation of

A method for metallurgically bonding cast-in-place cylinder liners 12 to a cylinder block 38 includes first coating the outer surface of the liners 12 with a low melting point molten metal material 14 and allowing it to solidify. The coated liners 12 are then positioned within a cylinder block casting mold 22 and molten cylinder block metal introduced into the mold 22. At a time prior to the cylinder block metal contacting and surrounding the coated liners 12, induction heating coils 28 are activated to premelt the coating material 14. The molten cylinder block metal then contacts and mixes with the molten coating metal 14 to form a metallurgical bond between the liners 12 and cylinder block 38 upon solidification.

Method for metallurgically bonding cast-in-place cylinder liners to a

A casting core (42) for forming a water jacket chamber (28) within a cylinder block (22) includes a bonded sand continuous wall portion (48) for forming a water passage (30) encircling a plurality of the cylinders (24) and through which water is circulated for cooling the perimeter of the cylinders (24). The casting core (42) also includes a bridging portion (46) that extends cross-wise in the wall (48) for forming a thin water passage bypass (32) extending through the thin web of cylinder block material (26) separating the adjacent cylinders (24) for providing cooling between the piston cylinders (24). The bridging portion (46) comprises a metal support element (64) covered by a sleeve of woven refractory material (66). A method is also provided for producing a cylinder block having such a casting core (42).

Casting core and method for forming a water jacket chamber within a cast

A countergravity low-pressure casting apparatus (10) includes a feedback control system (98) which continuously measures the actual pressure of metal being pumped into a mold (12) and controls the voltage applied to an electromagnetic pump (66) to conform the actual metal pressure with the ideal metal pressure versus casting cycle time fill schedule (96).

Apparatus and method for controlling the countergravity casting of

A permanent metal mold (12) has a casting cavity (18) within which variable thickness molten metal articles (20) are cast. Portions (26) of the casting cavity walls (16) are formed oversized and lined with sand (44) to conform with the external size and shape of certain thick (46) and thin (48) sections of the cast article (20). The thickness of the sand liner (44) is reversely correlated to the thick (46) and thin (48) sections of the article (20) to cause these sections (46, 48) to cool at different rates in order to achieve an approximately equalized cooling time of these sections (46, 48). Other portions (50, 52) of the casting cavity walls (16) are formed bare of the sand liner (44) and conform with the external size and shape of other corresponding sections (54, 56) of the cast article (20). These bare metal portions (50, 52) can either be heated or cooled or both during casting in order to precisely control the cooling rates of these other sections (54, 56) of the cast article (20) and thus precisely control their resultant physical properties.

Mold and method for making variable thickness cast articles

A countergravity casting apparatus (10) includes a mold (12) supported above a furnace (14) containing a supply of molten metal to be cast into the mold (12). An electromagnetic pump (66) is accommodated in a casting chamber (46) of the furnace (14) and pumps the metal against gravity from the furnace (14) into the mold (12). The casting chamber (46) is enclosed by an insulating cover (40) and defines an air space over the metal in the chamber (46). A lance (64) extends through the cover (40) and delivers inert gas into the air space and purges it of outside atmospheric gases that would otherwise contaminate the metal in the chamber (46).

Method and apparatus for countergravity casting molten metal

A sleeve of woven heat resistant material is axially compressed (22) to enlarge its cross-sectional area and perimeter. A support element (24) is disposed within the sleeve (22) to support it in its enlarged perimeter condition (26). The sleeve-covered support element (18) is then disposed in a cavity (14) of a casting mold (12) and molten metal (36) is cast into the cavity (14) and around the sleeve-covered support element (18). The molten metal (36) is allowed to solidify to form a cast article (16). The support element (24) is then withdrawn from within the sleeve (22), leaving the sleeve (22) within and adhered to the walls of the passageway (20) of the article in the expanded perimeter condition (26). A tension force A is applied to the sleeve (22) forcing it to stretch into a smaller cross-sectional area and perimeter (28) and causing the sleeve (22) to detach from the casting (16) for easy removal.

Method for forming cored passageways within cast metal articles

A method for eliminating porosity defects in aluminum cylinder blocks (22) having cast-in-place metallurgically bonded cylinder liners (12) includes coating the liners (12) with a low melting point molten metal such as zinc and thereafter removing a virtually entire outer layer of pure Zn, which would otherwise melt during casting and invade the block metal, leaving behind shrinkage defects in the resultant cylinder block (22).

Method of eliminating porosity defects within aluminum cylinder blocks

A counter-gravity metal casting apparatus (10) comprises a reservoir (14) having a casting chamber (46) therein. An electro-magnetic pump (66) is accommodated in the chamber (b 46) and is responsive to input voltage for pumping molten metal from the chamber (46) into an above-situated distribution vessel (78) and mold (12). The chamber 46) is enclosed by cover (40) and supplied with inert gas (60) for purging the space (62) above the metal or outside atmospheric contaminated gases. A feed back controller (98) is also provided for continuously measuring the actual pressure of the pumped metal of the casting cycle and then controlling the output of the pump (66) to conform the actual metal pressure with an ideal reference metal pressure versus casting cycle time schedule.

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Bristol, IN, United States of America

John W Kuhn