PURPOSE: To improve the product quality and prolong a die service life by forming dummy projections on the outside of a projection forming a hollow grooved shape on the outermost part of a forming projection of a male die.
CONSTITUTION: Dummy projections 40, 40 having a nearly equal shape to that of projections 11a are formed on the farther outside of the outermost projections 11a, 11a forming a hollow grooved shape on a forming projection 12 of a male die 1. A thickness t1 of the projections 40 is set to be equal to or thicker than a thickness t2 of other projections 11. A gap l1 between the projections 40 and 11a is positively held to be a similar distance to a gap l2 between adjacent projections 11 to ensure a flowing amount of a material to be formed into the peripheral part of the projections 11a. At the time of pouring the material from a container into a forming projection 12, an extruding pressure of the material is loaded on the projections 40 and does directly not act to the projections 11a, 11a for a hollow grooved shape. The product quality is improved and the die service life is prolonged because deflection of the projections 11a is completely prevented.
OKUBO KUNIO
MORITA TADAAKI
SUDO MASAMI
INABA NOBUO
