METAL MOLD FOR MOLDING HELICAL GEAR AND HELICAL GEAR MOLDING EQUIPMENT

PROBLEM TO BE SOLVED: To provide a metal mold for molding a helical gear which can prevent inclination of a segment die and improve accuracy of a tooth form, and helical gear molding equipment.SOLUTION: Since a concave guide surface 42 of die holding surface 41 in a holding ring 40 is so made as to be a concave inclined plane and a convex guide surface 33 of a held surface 32 in a segment die 30 is so made as to be a convex inclined plane, the segment die 30 is guided by mutual engagement of the concave inclined surface and the convex inclined plane.EFFECT: Rattling does not occur between the die holding surface 41 of the holding ring 40 and the held surface 32 of the segment die 30, the segment die 30 is not inclined even if a reaction force based on a torsional angle of a tooth form acts on the segment die 30 when molding a helical gear, and as a result, accuracy of the tooth form can be improved.SELECTED DRAWING: Figure 2 【課題】セグメントダイスの傾きを防止し、歯形の精度を高めることができるヘリカルギヤの成形金型及び成形装置を提供する。【解決手段】保持リング４０におけるダイス保持面４１の凹ガイド面４２を凹斜面とし、セグメントダイス３０における被保持面３２の凸ガイド面３３を凸斜面としたので、凹斜面と凸斜面とが互いに係合することでセグメントダイス３０がガイドされる。【効果】保持リング４０のダイス保持面４１とセグメントダイス３０の被保持面３２との間にガタつきが生じず、ヘリカルギヤ成形時に歯形のねじれ角に基づく反力がセグメントダイス３０に作用しても、セグメントダイス３０が傾くことが無いため、結果、歯形の精度を高めることができる。【選択図】図２