| 摘要 |
PURPOSE:To prevent entering of molten metal into the gap of a gas vent groove by forming the gas vent with shape memory alloy so as to plug the gas vent groove by deforming the alloy at the time of pouring the molten metal. CONSTITUTION:The gas vent 4 formed of the shape memory alloy is arranged to the gas vent groove 3 provided at an upper die 1a under the condition of inserting the gas vent 4 from upper side. When the gas vent 4 is heated with the molten metal as the poured molten metal runs into cavity 2, the tip part of the gas vent 4 at the cavity 2 side in contact with the molten metal, is suddenly deformed so as to become the preset outer diameter size (c) to plug the gas vent groove 3. By this method, the entering of molten metal into the gas vent groove 3 can be prevented hence reducing casting defect. |
