| 摘要 |
PROBLEM TO BE SOLVED: To provide a blanking die which can improve the working accuracy of blanking by preventing the warping of the blanked product and the sag, fracture, etc. of the sheared surface, and further to provide a method for manufacturing a blanked product using the same blanking die. SOLUTION: In the die 3 for blanking a workpiece W in cooperation with a punch 2, a cutting edge 31 is provided at the edge portion of a through-hole 30 into which the punch 2 is inserted. The cutting edge 31 has a cutting tip 32 which is formed at the edge portion of the opening of the through-hole to shear the workpiece, and a cutting surface 33 composed of a first tapered surface 33a which is tilted so as to reduce its diameter with the distance from the cutting tip 32 toward the inside of the through-hole 30, and so as to gradually make its tilting angleθ1 andθ2 furthermore acute with the distance toward the inside of the through-hole 30, and so as to be connected to the edge portion of the opening of the through-hole 30, and a second tapered surface 33b having a tilting angle acuter than the tilting angle of the first tapered surface 33a. COPYRIGHT: (C)2008,JPO&INPIT
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