| 摘要 |
PURPOSE:To form threads with high accuracy by working a thread rolling part to above the diameter which has added a rolling lower diameter and an expected carburizing layer thickness, performing carburizing and quenching to a crank shaft, and thereafter, removing a carbonized layer of said part, and executing thread rolling. CONSTITUTION:In a method for threading to a part of a crank shaft, etc. for which carburizing and quenching are required, by means of rolling, a part to be worked 2 of a shaft 1 is worked preliminarily to above the diameter which has added a rolling lower diameter and an expected carburized layer thickness, and the carburizing and quenching are performed to the shaft 1. Subsequently, the carburized layer of the part to be worked 2 is ground or cut, worked to the rolling lower diameter of the part 2, and thereafter, the part 2 is brought to threading by means of rolling. In this way, the crank shaft having high accuracy can be manufactured by a simple working process. |
