| 摘要 |
<p>A press-forming method in which a multi-shaft press device that actuates a plurality of shafts independently is employed to draw the bottom of a recess formed in a base material by pressing out the bottom of the recess into a hollow shaft. The press-forming method is provided with a first step in which the base material is set in a concave mold; and a second step in which a first tool presses the end face of a side wall, which defines the recess in the base material and forms a cylindrical shape, in the axial direction of the first tool at a first speed (Vi), while a second tool simultaneously molds the bottom of the base material by pressing out the bottom of the base material in the axial direction of the second tool at a second speed (Vb). At the second step, the ratio (Vb/Vi) of the second speed (Vb) to the first speed (Vi) is controlled to be within the range of 0.7 to 1.5.</p> |
