| 摘要 |
PURPOSE:To form tapers in different directions to the teeth of a work and to roll crown teeth by constituting the finishing tooth group of flat dies in such a way that the trace helix angles of the 1st tooth group and the 2nd tooth group thereof are opposite to each other. CONSTITUTION:Flat dies 3a, 3b consist both of a chamfer tooth group KU, a finishing tooth group S1 and a relief tooth group N1 and the group S1 is constituted of the 1st tooth group S1- I and the 2nd toogh group S1-II. The tooth T1 of the group S1- I in this stage is provided with the trace helix angle larger by some angle beta than the trace helix angle of the work. On the other hand, the tooth T2 of the group S1-II is provided with the trace helix angle smaller by some angle beta than the trace helix angle of the work. A pair of the flat dies 3a, 3b having the same constitution are disposed to face each other with the work 4 in-between and are moved in the opposite directions. Therefore the tooth T1 forms a tooth face 3c to the work 4 and the tooth T2 a tooth face 3d thereto. |
