| 摘要 |
PURPOSE:To eliminate waviness on the tooth trace of a tooth and to roll a helix gear having good accuracy with a short die by providing a grade of a specific length in the central part of a flat die in a longitudinal direction from the gnawing end thereby providing a relief part thereto. CONSTITUTION:When a work is rolled by a die 50, rolling at both ends of the work is completed in the central parts 5b-6b of the die and only the effective width (width 7b-8b or below) of the work is finish rolled by the central and succeeding parts in the longitudinal direction of the die. Both ends hardly contact each other on account of chamfering 52 in the stage of finishing and therefore the inferiority owing to a difference in the shape of both ends is eiliminated. Since the width contact is gradually decreased by the chamfering 52 of the end faces provided with the grades 5b, 6b, 7b, 8b from the finished tooth part toward the relief tooth part, the fluctuation in load is decreased and the waviness on the tooth trace of the tooth is improved. |
