Manufacturing crankshaft for engine e.g. gasoline engine, by positioning single core within cavity of mold having first half and second half forming exterior shape of crankshaft, and introducing molten metal into cavity to form crankshaft

摘要

The method comprises positioning a single core within a cavity of a mold having a first half and a second half forming an exterior shape of a crankshaft, where the exterior shape of the crankshaft includes pin bearing journals (28) and main bearing journals (26), introducing a molten metal into the cavity to form the crankshaft, where the molten metal flows into the cavity and around the single core to form a hollow section (32) extending through the pin and main bearing journals. The method further comprises forming the single core as a unitary piece to have a shape. The method comprises positioning a single core within a cavity of a mold having a first half and a second half forming an exterior shape of a crankshaft, where the exterior shape of the crankshaft includes pin bearing journals (28) and main bearing journals (26), and introducing a molten metal into the cavity to form the crankshaft, where the molten metal flows into the cavity and around the single core to simultaneously form a hollow section (32) extending through the pin bearing journals and the main bearing journals. The method further comprises forming the single core as a unitary piece to have a shape that passes through the pin bearing journals and the main bearing journals. The single core: includes a part of material forming a planar shape and a non-planar three dimensional shape and having a cross section defining a non-circular cross sectional shape; is symmetrical about a longitudinal center of the core; and defines a non-linear path relative to a longitudinal axis (24) of the crankshaft for the hollow sections extending through the pin bearing journals or the main bearing journals. The non-circular cross sectional shape of the single core includes an elliptical shape. A non-linear path comprises a path that is angled relative to the longitudinal axis to direct the hollow portion of a region of the crankshaft with high voltage straight away. The single core further includes a connecting portion having a surface that defines a portion of main bearing journals and/or the pin bearing journals, or counterweights (30).