| 摘要 |
PROBLEM TO BE SOLVED: To improve deep drawability by preventing fracture by evading the concentration of local strain caused by thickness difference which is present on a plate surface and ununiform material inflow at deep drawing due to strength ratioαof a high strength material (t1×TS1) to a low strength material (t2×TS2);α=[t1×TS1]/[t2×TS2]>1, in deep drawing of a different-thickness different-strength press forming material (material to be worked). SOLUTION: When deep-drawing the material 1 to be worked ( for example, a different-thickness different-strength tailored blank ), a counter punch 7 opposing to a punch 6 is incorporated in the die cavity, the region of the material 1 to be worked which is in the range within the die cavity which is brought into contact with a punch head is held with the punch 6 and the opposite counter punch 7, by forming the material in a holding part (67) in the state where inplane displacement and movement is restrained with the punch head by frictional force which is obtained corresponding to the output of counter punch force, the deep drawing is performed while making the material on the high strength side and the material on the low strength side in a blank holder part (511) flow in uniformly. COPYRIGHT: (C)2006,JPO&NCIPI
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