| 摘要 |
PROBLEM TO BE SOLVED: To enable an excellent product to be cast by preventing the occurrence of swell, a shrinkage cavity and sand burning of a mold cavity part caused when casting cast iron and by putting the inside of the product cavity part into a proper pressure state.SOLUTION: In casting the cast iron, a hollow-shaped pressure absorbing part 6 having strength enabling the pressure absorbing part 6 to crack or dent while pressure in the inside of a mold cavity part becomes constant pressure or more due to increase pressure of molten metal 7, is provided in a feeder head part 5 of an upper die 4 or in an exterior vicinity to the feeder head part 5, or the empty-shaped pressure absorbing part 6 is provided outside the feeder head part 5, on the other side of a partition wall having strength enabling the partition wall to crack or dent when the increase pressure becomes constant pressure or more, and when pressure inside the mold cavity part exceeds the constant pressure due to the increase pressure of the molten metal 7, the pressure absorbing part 6 or the partition wall 8 cracks or dents, and absorbs the increase pressure by increasing the volume of the inside of the mold cavity part, so that the cast iron can be cast while the inside of the product cavity part 3 does not receive excessive pressure. |
