| 摘要 |
The present invention relates to a method of forming a key portion on a sheet metal member, the key portion being useful in coupling of a shaft to a member such as a pulley used in an automobile. According to the method of the invention, an inner metal part of a cylindrical portion of the sheet metal member is pressed in the axial direction so that the inner metal part is removed away and a predetermined place of the inner metal part remains, the remaining metal part being used as the key portion. Pressing the inner metal part in the axial direction of the cylindrical portion can be conducted by a pressing process in which a pressing die is moved in the axial direction of the cylindrical portion. A key portion can be easily formed on the cylindrical portion, and an inner flange can be formed together with the key portion. Therefore, a member having a cylindrical portion which has a key portion and an inner flange can be provided without using a casting process, as a lightweight sheet metal member which is tough and economical. |
