CASTING METHOD OF ALUMINUM CYLINDER BLOCK

PURPOSE: A casting method of an aluminum cylinder block is provided to improve fusion between cast iron liners and the aluminum cylinder block by injecting a small amount of molten metal into the liners in advance to preheat the liners with heat of the molten metal before casting the cylinder block in a mold. CONSTITUTION: The casting method of an aluminum cylinder block comprises a first process of integrally forming liner supporting cores on the upper surface of a head face core, and inserting cast iron liners through the liner supporting cores so that the cast iron liners are mounted on the upper surface of the head face core; a second process of assembling water jacket cores onto the outer side of the liners mounted on the upper surface of the head face core in the first process through core prints; a third process of assembling the head face core, liners and water jacket cores integrally assembled in the second process into runner parts of a lower mold through the head face core; a fourth process of front, rear, left and right side molds(15,17,19) are assembled into dowel grooves a plurality of which are formed along the edge of the lower mold as covering the liners and water jacket cores through dowel pins of the lower part after the third process; a fifth process of assembling an upper mold at the upper part of the front, rear, left and right side molds(15,17,19) installed in the fourth process, assembling a liner preheating molten metal injection cup corresponding to the upper part of the liners on the upper mold, and installing a molten metal injection cup for the mother body of the cylinder block corresponding to a down sprue of the upper mold; a sixth process of preheating the liners by injecting a small amount of molten aluminum through the liner preheating molten metal injection cup assembled in the fifth process; and a seventh process of casting the cylinder block along with the liners preheated in the sixth process by injecting the molten aluminum through the molten metal injection cup for the mother body of the cylinder block after the sixth process.