PRESSING DIE AND PRESSING METHOD

摘要

PROBLEM TO BE SOLVED: To manufacture a green compact non-uniform in thickness but uniform in density using a dry-type uni-axial press by providing an elastic punch formed of an elastic material deformable by the pressing pressure to be applied in contact with a raw powder material between the punch and the raw powder material. SOLUTION: A surface in contact with a portion corresponding to a thinnest portion of a green compact is a first reference surface CC. A surface in contact with a portion corresponding to a thickest portion of the green compact is a second reference surface DD. The length h1 of a perpendicular on the first reference surface CC from an arbitrary point on a forming surface of an elastic punch is equal to the filling height of a raw powder material corresponding to the thinnest portion of the green compact subtracted from the filling height of the raw powder material at the point. The length h2 of a perpendicular to the second reference surface DD from an arbitrary point on a rear surface of an elastic punch is equal to the optimum pre-stroke at the point subtracted from the optimum pre-stroke corresponding to the thickest portion of the green compact.