歯車転造機構の研究(第1報)

Abstract

There are two contact phases in roll forming process. One is the conjugate action between the roller tooth and the blank tooth. The other is the non-conjugate action between the tip edge of roller tooth and the fillet surface or the bottom land of blank tooth. In the reports of this type published to date the operations are classified as the rough and the finish rolling because of the amount of material that must be moved by the rolling. But in this report the operations are classified by the above contact phases, and the experimental consideration is done to get the effect of phases on the pitch error and the profile error for the module m 3, spur and helical gears. The following results are obtained: If the gear blank meshes with dies holding conjugate action during rolling, the accumlated error after rolling is 5 to 20 μm, and the profile error is 13 to 20 μm, where the material used is JIS S 20 C steel, the tooth depth of pre-gashed blank is 6.0 to 7.0 mm in range. But in the same condition the material and the pre-gashing depth the non-conjugate action at the fillet surface of the blank tooth may be inserted into the process, the accumlated error after rolling becomes 10 to 20 μm, the profile error becomes lower grade 20 to 30 μm. After rough rolling, the rolled gears are further processed by finish roll holding conjugate action. In this case the accumlated error held the same level, but the profile error is improved 15 to 20 μm, though 40 μm in rough rolling. Further, when the rough and finish combined rolling is applied to the high hardness metal JIS S 55 C steel, the profile error is improved higher grade 5 to 10 μm.