| 摘要 |
PURPOSE:To increase the hardness of a tooth frank and a surface of tooth simultaneously by cooling rapidly a gear material of low hardness, which is cooled gradually at the specified temperature for high frequency contour hardening after gear cutting the low hardness material. CONSTITUTION:A form of a gear is gear cut, using a gear material in a heat treatment state and a low hardness material, which is sperior to gear cuttability. After all tooth part of the gear is heated with high frequency by low power to the austenited temperature, it is carried out by a short time rapid cooling, such as water cooling. Thus, all tooth parts are quenched with high frequency to be a hardened layer B, and a tooth frank part is highly hardened to secure the static intensity of the gear and a low cycle time intensity. Consequently, at the time that a rapidly cooled gear has a residual heat, the tooth part of the gear is quenched with high frequency by high power to form a contour hardened layer A along the tooth form and secure the fatigue strength and sperior durability of the gear. |
