| 摘要 |
PURPOSE:To reduce casting defects by quickly eliminating the cumbustion gas of a pattern generated at casting time by providing in parallel along the pattern the gas vent pipe equipped with a vent part at the upper and lower parts of the sublimation pattern in a casting sand. CONSTITUTION:A sublimation pattern 4 and gas vent pipes 5, 5 are arranged in the casting sand 3 inside the metal frame 2 of the mold 1 for casting the sublimation pattern. The sublimation pattern 4 made of a foamed synthetic resin is composed of the plural product models 9 provided in the right and left lines centering around a gate pattern 7 and runner pattern 8 and the gate pattern upper part 7 is projected inside the pouring basin 10 of a refractory material. The gas vent pipe 5 is provided in parallel vertically along the lining direction of the model at the upper and lower parts of the product model 9 of each line and one end thereof is communicated to the open air. via an exhaust pipe 12. The generated gas diffused in the casting sand at the time when a molten metal is poured is removed from the cast sand via the exhaust pipe 12 of the degassing pipe 5 from the vent part. The generation of casting defects can thus be prevented with no gas remaining in the casting sand 3 or cast cavity. |
