| 摘要 |
<p>PURPOSE:To set pouring timing and pouring speed as desired by providing a molten meterial blow hole to the bottom wall of a crucible and selecting the timing of applying gas pressing or pulling force of molten material blow and the magnitude of the pressure. CONSTITUTION:When the material 33 in a melting furnace 1 is melted and reaches an adequate temperature, arc discharge is stopped and the inside of the melting chamber 1 is boosted. This pressure causes the molten material 33 to be blown through a molten material blow hole 17 and be poured into the molding cavity 23 through a sprue 22. At this time, the molten material 33 is pressed under the pressure lower than the inside of the melting chamber 1 from the sprue 22 side and while its boiling is being suppressed, it is blown out at a correct speed and flows smoothly deep into the molding cavity 23, thus it correctly solidifies from the innermost end side toward the sprue 22. If the pouring temperature and pouring speed are maintained in a correct range by arbitrarily selecting the timing of applying these differential pressures and the magnitude of the differential pressures, the material is cast precisely to the correct shape even in the thin and broad portions of the product.</p> |
