| 摘要 |
PURPOSE:To perform correct centering, to prevent deformation of die due to working pressure and to perform ironing at high accuracy in ironing a cylindrical work, by fitting an annular die to outer periphery of a punch and die. CONSTITUTION:A cylindrical work A drawn by a separate press is set on a blank holder 14 to cover the upper end of a punch 13. When the ram of the press is lowered, a knock-out member 6 comes into contact with the cylindrical work A and pushes down to fit it to the punch 13. Just before completion of pushing down, a cylindrical part 20 of the second die 19 starts to fit to the first die 18. When the cylindrical work A is pushed down until it completely fits to the punch 13, a die 5 goes down ironing the outer peripheral wall of the cylindrical work A. By this ironing, the thickness of outer peripheral wall of the cylindrical work A is reduced, and finished to a specified outer diameter which is smaller than an original diameter. At the same time, the degree of drawing becomes greater and attains a specified drawing height. |
