| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a hollow engine valve capable of simplifying a producing step and achieving improvement in accuracy of processing.SOLUTION: A method for producing a hollow engine valve 1 including a valve body 10 where a hollow hole 10c is formed over a valve umbrella part 10a and a hollow shaft part 10b, wherein a solid round bar 11 that is to be a raw material for the valve body 10 is formed into a half-finished product 12 by performing hot-forging process once, the half-finished product 12 is formed into a half-finished product 13 by performing rotary swaging to the half-finished product 12, the half-finished product 13 is formed into the valve body 10 by subjecting necking to the half-finished product 13, and an axis end sealing member 20 is connected to an end of the hollow shaft part 10b in the valve body 10, is provided. |
