CASTING DEVICE USING CONSUMABLE PATTERN

PURPOSE:To improve running of molten metal in a product part by constituting patterns with a first pattern composed of a material, which gas produced quantity is little at the time of losing this, and a second pattern composed of a material, which gas produced quantity is comparatively much at the time of losing this, and arranging a pressure adjusting means of a backup material layer. CONSTITUTION:A sprue part 7a and a running part 7b in a consumable pattern P, i.e., the first pattern for forming casting design part 7 except the product part is formed with the material, which gas produced quantity is little, and the second pattern for forming the product part is formed with the material, which gas produced quantity is much and difficult to carburization. At first, in the casting design part, improvement to the running of molten metal and prevention to blow-back of the molten metal, and in the product part, prevention to the carburization, can be obtd. at the same time. In the casting design part, the carburization is developed, but after casting, this part is rejected. At the time of pouring the molten metal into the first pattern, pressure reduced degree around the first pattern is adjusted to comparatively low with a pressure adjusting means. By this method, mold collapse or burning of the backup material layer around the first pattern, are prevented. Further, at the time of pouring the molten metal into the second pattern, the pressure reduced degree is adjusted to comparatively high, and running of molten metal in the product part is improved.