| 摘要 |
PURPOSE:To perform low pressure casting with high working efficiency by connecting two molds alternately to a stalk sprue, charging molten metal into the mold through the sprue and allowing solidification and product removal to take place in the other mold while charging molten metal into one mold. CONSTITUTION:One metal mold 40 is connected to a stalk sprue 17 and compressed air is blown through a pressure piping 16 onto the surface of the molten metal in a crucible 12 in a furnace 10 to charge the molten metal into the mold 40. Upon lapse of a prescribed time, a discharge valve is opened to drop the pressure in the furnace 10 slightly and to lower the molten metal level in a stalk 14. Thereafter the upward and downward moving mechanism of a lower plate 20 is operated to move the two metal molds upward together with the plate 20 to disconnect the mold 40 from the sprue 18. In this position, cylinders 46a, 46b are driven to slide the mold 40 and to connect the other metal mold 38 to the sprue 18 in the same manner as mentioned above. In the stage of charging the molten metal into the mold 38 under pressure, the mold 40 is subjected to solidifying, knocking-out, etc. |
