Die apparatus and control method

A die apparatus comprising:

• an upper die including a stripper plate and a blanking punch;
• and
• a lower die, wherein
• the die apparatus is configured to
• perform a blanking or stamping operation that is sequentially carried
• out on a sheet by using the blanking punch to blank or stamp out an iron core, the die apparatus
• further including:
• a tip end part blanking punch provided at the upper die and configured to blank a tip end part of the sheet through a punch holding unit, wherein
• the punch holding unit includes:
• a punch plate which holds the tip end part blanking punch such that the tip end part blanking punch is movable with the punch plate;
• a punch plate moving mechanism configured to lower the punch plate into a lowered state such that the punch plate is separated from the upper die when the tip end part of the sheet is blanked, and to raise the punch plate in a raised state such that the punch plate is closer to the upper die than when the punch plate is in the lowered state;
• and
• an actuating mechanism which operates the punch plate moving mechanism during the blanking or stamping operation of the upper die only when the tip end part of the sheet is blanked, and wherein
• when the tip end part blanking punch reaches a bottom dead center, an end of the tip end part blanking punch is protruded downward from a lower surface of the stripper plate,
• whereas when the sheet is blanked or stamped by the blanking punch after the tip end part of the sheet is blanked, the end of the tip end part blanking punch is held above the lower surface of the stripper plate.