| 摘要 |
PURPOSE:To prevent defective casting due to gas when casting molten metal in a metal mold at a low pressure, by reducing the internal pressure of the metal mold by inserting a pipe into another gas purging pipe at the upper of the metal mold and by spouting high-pressure air up. CONSTITUTION:On the lid of ladle 1, the metal mold consisting of mold cope 5 and drag 4 is arranged, ans stock 3 having the hollow part communicating with the casting space 9 in the metal mold is steeped in molten metal 2 in foundry ladle 1. The internal pressure of foundry ladle 1 is increased to cast molten metal 2 in casting space 9 via stock 3. In this case, pipe 11 for squeeze air is provided in gas purging pipe 10, provided to the metal mold, with its tip opening part 12 up. During the casting, squeeze air is sent to pipe 11 and spouted from the tip opening part. Then, the air in pipe 10 is at a negative pressure and the air in space 9 and gas produced from a coating mold layer are sucked and discharged from pipe 10, so that defective casting of a product due to the gas can be prevented. |
