| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a failure of remaining foreign matter in a workpiece when air is blown in from openings at the end parts of the workpiece by preventing air from being sucked to the inside of the work through the openings at the end parts of the workpiece. SOLUTION: In this method, by blowing air from openings 14, 15 of the end parts of a workpiece 10 into the workpiece 10 having the shape of a pipe and plural outer peripheral openings 20 formed along axial direction, the air is discharged from the outer peripheral openings 20 to remove foreign matter in the workpiece 10. The outer peripheral openings 20a, 20b among the outer peripheral openings 20 in which air is sucked from the outside of the workpiece 10 to the inside thereof when air is blown in from the opening 14 of the end part of the workpiece 10 are closed, and in this state, air is blown in from the end part opening 14 and is discharged from the outer peripheral openings 20 that are not closed. |
