| 摘要 |
PROBLEM TO BE SOLVED: To provide a thickening processing method of a hole end part capable of thickening the end of a hole, while maintaining accurately an inner surface shape of the hole, and reducing waste of a material.SOLUTION: A prepared hole 11 is punched out through a metal plate 10, and the prepared hole 11 is burring-processed to form a rising part 12 on the periphery of the prepared hole. A guide rod 15 is inserted into the center of the rising part 12, and a ring-shaped punch 16 is lowered to crush the rising part 12, and to thereby form a thickened part 17 on the periphery of the prepared hole. The thickness of the thickened part 17 can be controlled by a height H of the rising part.SELECTED DRAWING: Figure 2 |
