| 摘要 |
PROBLEM TO BE SOLVED: To form a product having large projection area by forming the cross sectional shape as a round shape and providing a runner whose cross sectional area is gradually reduced on the way to a sprue. SOLUTION: The cross sectional area of the round runner part 2 is set so as to be gradually reduced as approaching to the sprue part 5. Further, the runner part near the sprue part 5 is formed as a fan-shape runner part 4 so that the arc part of the fan becomes the sprue part 5, and this cross sectional area is gradually reduced as coming to the sprue part 5. When the large and thin casting product 1 is formed by using this die, since the projection area of the runner part 2 is reduced in the way from a feeder head 3 to the sprue part 5, the molten metal power which tends to open the die at the forming time, is reduced. Further, since the cross section of the runner part 2 is round, the area where the molten metal is brought into contact with the die, becomes the minimum, and as a result, since the heat loss of the molten metal is reduced and the solidification of the molten metal can be delayed, the filling of the molten metal in the die is smoothly executed. |
