Patent ID: 8291740
Filing Date: 2012-10-23
Classification: B21D,B21J

Abstract:
1. A hot forming die which is configured to press-form a heated steel plate and to cool the heated steel plate by ejecting a cooling medium onto the heated steel plate when the heated steel plate is held on the die, the hot forming die comprising: a main supply path configured to facilitate the cooling medium to pass there through; a plurality of branch supply paths extending from the main supply path and including ejection ports which open at a forming surface of the die, and which are configured to eject the cooling medium; and at least one nozzle member fixed on a part of an ejection port side of each of the branch supply paths and configured to restrict a passage amount of the cooling medium via a passage hole which facilitates the cooling medium to pass there through, wherein the at least one nozzle member is arranged in the branch supply path, and an end face on the ejection port side of the at least one nozzle member is located far from the forming surface of the die, wherein the end face on the ejection port side of the at least one nozzle member and the forming surface of the die is distanced by at least 0.05 mm and at most 50 mm, and wherein a cross-sectional area of a passage hole in the at least one nozzle member is smaller than the cross-sectional area of the branch supply.