| 摘要 |
PURPOSE:To manufacture easily a damper case without wasting a material, by performing drawing and pressing which continues spinning work and coining work. CONSTITUTION:A damper case 1 is provided like a long pipe by spinning work, and a bottom part 2 is provided in a closed state. Coining work is performed by utilizing residual heat of the spinning work. As for the coining work, a mandrel 3 whose tip part is provided in a prescribed shape is inserted into the damper case 1 through a coining forming machine, and the inside bottom part of the case 1 is compressed between the mandrel 3 and a die 4 and is formed to a bottom face 5 of a prescribed shape. Also, the outside circumferential face of the bottom part 2 is drawn and formed by placing the inside mandrel 3 by a drawing coining punch 6 consisting of ceramics or a sintered hard metal. |
