Hollow drive shaft using upsetting method and manufacturing method therefor

A method of manufacturing a hollow drive shaft using an upsetting method, the method comprising:

• (A) inserting both ends of a workpiece cut to a predetermined length into a heating unit and heating both ends of the workpiece to a predetermined temperature;
• (B) inserting both ends of the heated workpiece into a forming die and then pressing both ends of the heated workpiece with a mandrel in order to perform an upsetting process so that an outer diameter at both ends of the workpiece is greater than an outer diameter of a middle part of the workpiece;
• (C) performing, after completing the performing of the upsetting process, a CNC machining process of performing turning machining on both ends of the workpiece, which has been subjected to the upsetting process, to a predetermined dimension and shape by using a computer numerical control (CNC) lathe;
• (D) performing, by using a form rolling machine, a rolling process to form splines at both ends of the workpiece that has been subjected to the CNC machining process;
• and
• (E) performing a high-frequency heat treatment process of heating, by using a high-frequency heat treatment device, the workpiece, which has been subjected to the rolling process, to a predetermined temperature, cooling and quenching the workpiece, heating again, by using the high-frequency heat treatment device, the quenched workpiece to a predetermined temperature, and then cooling and tempering the workpiece.