Ford Motor Company Limited

William M Justusson

Allen D Ackerman

Conrad G Perkey

Robert A Martin

A method is disclosed for making ductile iron castings having thin walls. Molten grey iron (preferably 3.5-4.2%C, 1.5-2.4% Si, and no greater than 0.65% carbide formers) is introduced to a mold assembly and nodularized/inoculated in such assembly prior to passing into the mold cavity of the assembly. The treated molten iron is fed into the mold cavity and into one extremity of a thin space thereof (0.2 inches thick or less and a length of at least 12 times the thickness). The treated molten metal is additionally mixed by vortical or turbulent flow immediately downstream of the treatment chamber as it is being conveyed to the mold cavity. While continuing to feed the treated molten iron to fill the mold cavity, a reservoir of the treated molten iron is created at a midstation of the thin space. The reservoir acts to conserve the heat of the molten metal and thus feed hotter molten metal to the remainder of the thin space and other connected cavity portions. The reservoir space also serves to define an integral functional part of the casting when solidified.

Method of making thin-walled ductile iron castings

A thin-walled exhaust gas manifold casting structure for an internal combustion engine is disclosed. The manifold is comprised of nodular iron and has walls defining a plurality of inlet ducts interconnecting with a shallow elliptical outlet duct, the walls having a generally uniform thickness in the range of 0.12-0.15 inches. An integrally cast rib extends across at least a plurality of inlet ducts to reduce thermal flexing in service. The rib, subsequent to casting, is bored to define a hollow cylinder having ports communicating with most of the inlet ducts for carrying a secondary air supply. The inlet ducts are also arranged to achieve compactness in the overall envelope of the manifold by (a) restricting the dimension between the inlet duct openings and the outlet duct opening to less than the major axis of the elliptical outlet opening, (b) interconnecting the inlet ducts with the singular outlet duct along generally one side thereof, and (c) limiting the included angle between the plane containing the inlet openings and the plane containing the outlet opening to about 50.degree..

Growing community of inventors

Farmington Hills, MI, United States of America

William M Justusson