| 摘要 |
PURPOSE:To make mass production of forming dies with high accuracy by working preliminarily the outside circumferential surface of the forming die then rolling the die with a roll provided with the shape corresponding to the final shape. CONSTITUTION:The circumferential groove 2 of a forming die 1 for oil seals is preliminarily worked by machining. A roll 14 having the circumferential end of angle elements (alpha, beta, theta) and curvature element (R) which are the same as the final shape of the die 1 is brought into press contact with the groove 2 of the die 1, and is rotated by a shaft 13 to apply surface finishing and shape finishing to the groove. Since the hardness of the die 1 is 20-30 deg. HRC, the hardness of the roll 14 is made about 60 deg. HRC. |
