HELICAL GEAR AND HELICAL GEAR MANUFACTURING METHOD

To provide a helical gear which is configured from a hard raw material such as iron or the like, and has a tooth having a large torsion angle or a large module value, and a helical gear manufacturing method for manufacturing said helical gear.SOLUTION: A helical gear 1, which has a gear part 10 and in which fiber flow parallel to a cross section of a tooth, which is cut in a direction perpendicular to a right angle of the tooth, is formed on the gear part 10, is molded in such a manner that a processed material is pushed into a metal mold at normal temperature by a forward extrusion system. A helical gear manufacturing method has: a spur gear molding process in which a spur gear is molded by a front stage metal mold by pushing the processed material into the front stage metal mold; and a gear molding process in which the helical gear 1 is molded by a rear stage metal mold by pushing the spur gear, which has been molded by the front stage metal mold, into the rear stage metal mold by a pushing component while holding and twisting the processed material around an axis of the spur gear by a twisting component.SELECTED DRAWING: Figure 1 【課題】鉄等の硬い素材により構成され、ねじれ角が大きな歯や、モジュールの値が大きな歯を有するはすば歯車、及び、当該はすば歯車を製造するはすば歯車の製造方法を提供すること。【解決手段】歯車部１０を有し、歯車部１０には、歯直角に対して直角な方向で切った歯の断面に平行なファイバーフローが形成されている、前方押し出し方式で常温の被加工材が金型に押込まれて成形されたはすば歯車１である。また、被加工材を前段金型に押込むことにより前段金型によって平歯車を成形する平歯車成形工程と、平歯車の軸心を中心に被加工材を捻り部材により保持して捻りながら、前段金型によって成形された平歯車を押込み部材により後段金型に押込むことにより、後段金型によってはすば歯車１を成形するはすば歯車成形工程と、を有するはすば歯車の製造方法である。【選択図】図１