CASTING METHOD OF HOLLOW CAM SHIFT

摘要

PURPOSE: A casting method of a hollow cam shift is provided to easily discharge a gas generated during casting by manufacturing a hollow part core with a glass tube on the outer circumferential surface of which spiral grooves are formed, and easily manufacture a hollow cam shaft by removing desanding process. CONSTITUTION: The casting method of a hollow cam shift comprises a first process of forming core print parts(5,7) at both fronts on the cam shaft casting surface of a lower mold(1), and arranging a glass tube core having a certain diameter forming the hollow part of a cam shaft on the casting surface of the lower mold(1) so that both ends of the glass tube core are installed and assembled at both sides of the core prints(5,7); a second process of uniting the lower mold(1) and an upper mold(15) into dowel grooves formed along the edge of the lower mold(1) through dowel pins(17) formed along the edge of the lower surface of the upper mold in the state that the glass tube core(9) is assembled into the lower mold(1) in the first process; a third process of performing gravity casting injection by injecting molten cast iron(21) from the upper part of the upper mold(15) through a sprue after the second process; and a fourth process of obtaining a cam shaft casting by rotating and pulling out the glass tube core(9) forming the hollow part of the cam shaft from one side of the glass tube core(9) so as to strip the glass tube core(9) after desanding and removing the upper and lower molds(15,1).