| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a punching method for an element capable of punching the element preventing an endless ring from being damaged with high precision and reducing a cost/working hour required for deburring. SOLUTION: A die 12 placing a plate material 3 has a bending end edge 19 of a curved shape in a cross sectional view at a cutting edge of the position corresponding to a neck 7 and an undercut. The punch 13 to push down the plate material 3 to an element shape is constituted so that the cutting edge 21 corresponding to the bending end edge 19 of the die 12 is separated from the bending end edge 19 of the die 12 larger than a cutting edge 21 of the other part. The element 1 is punched by the die 12 and the punch 13, the end edge between the neck 7 and the undercut is formed with a shear cross section (d) along the plate thickness direction and a breaking face (e) connecting thereto, further, a burr (f) is formed to one side face of the element 1 in non-contact with the endless ring through the breaking face (e).</p> |
