| 摘要 |
<p>Provided is a C crimping device capable of bending both edges of a sheet in a width direction in order to secure the roundness without affecting the performance of a steel pipe, including an upper forming unit having a pair of C-forming portions having a curved surface at a position corresponding to both edges of the sheet in the width direction, and a center forming portion disposed between the C-forming portions and having a protruding curved surface facing the bottom surface; and a lower forming unit having a curved surface corresponding to the shape of the C-shaping portions and the center shaping portion.</p> |
