| 摘要 |
PURPOSE:To prevent a sub-standard product due to a deviation of wall thickness and a damage of a metallic die due to a deviated load by dividing an upper punch to an outer punch and an inner punch and arranging the inner punch so that it is protruded beyond the outer punch and is movable free by backward and forward through a spring more than the outer punch so as it is protruding beyond the outer punch. CONSTITUTION:In case a blank material 1 is inclined and set above a lower punch 2, when the upper punch 4 is lowered, an inner punch 6 first pushes the blank material 1. Accordingly, the inner punch 6 corrects the posture of the material 1 by the pressing force of an urethane spring 9 at the rear end and a stroke difference of the extruded portion and an outer punch 5. Then by pressing the bottom part of the blank material against the lower punch 2 with the inner punch 6, the outer punch 5 is lowered for extrusion. Subsequently, an aperture end of the material 1 is extruded. And in the extrusion-molding, an external wall of the cup only is molded by an outer punch 5, and the punch 6 is held by an urethane spring 9 having no sufficient power for molding and it does not contribute for the molding.
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