| 摘要 |
PURPOSE:To decide the optimum shape of a neck-down core of a feeder head by finding a thickness of the neck-down core from the equation of heat conduction, related to molten metal, near both the side faces of the neck-down core and its opening diame ter from the rule of Chvorinov, respectively. CONSTITUTION:The neck-down core 5, forming the neck-down between the feeder head part 1 and the casting part 2 is made and arranged by using a sand mold at the lower end of the feeder sleeve 3, which fills up the feeder head 1 formed in the casting sands 7. At the time of making the neck-down core 5 having the above- mentioned opening part, at first, this model is imaged, and the equation of heat conduc tion on the molten metal near the both side faces is used and is calculated by substitut ing an initial condition and a boundary condition, to find the data on the change as passing time for the molten metal. Based on this data, the thickness of the above- mentioned neck-down core 5 is decided. Further by the rule of Chvorinov, the data on the solidifying proceeding velocity of the molten metal is found. By analysis of a coinciding point as passing time for both data, the inside diameter 6 of the above- mentioned core 5, of which the opening part does not clog by solidifying the molten metal is decided. |
