| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem as the expensive forming cost for obtaining a bottomed cylindrical shaft product with steps 320, having the complicated shape, such as a shaft hole 321, an upper small diameter part 322, a flange part 323, a large diameter part 324 and a lower small diameter part 325, shown in the figure 1, because the complicated process requires the transferring works and the product can not be formed in one process. SOLUTION: In a die-forging method, in which a forging blank is plastically fluidized by pressurizing in a forging die and formed into a prescribed shape, a forging process for forging by hitting a punch or pressing the die to the forging blank while retreating under state of loading back pressure by abutting a die pin on the one end surface of the forging blank, is applied and plural die pins are arranged in the same axis and also, these die pins vary their relative positions during forging process.
|
