| 摘要 |
<p>PURPOSE:To obtain a hollow pipe having strength in a structure and strength to bending, and being lightweight. CONSTITUTION:Pipe walls 11, 12, 13 of a hollow pipe are formed into corrugate shapes in relation to the circumferential direction of the pipe, and spirally continued along the pipe shaft direction in relation to the circumferential direction, and ribs in the radial direction are spirally and integrally formed on the inner surfaces of the pipe walls along the pipe shaft direction. Hollow small diameter cores 21, 22, 23 are integrally formed with the ribs along the center shaft of the pipe, the ribs 31, 32, 33 are radially provided at least in three directions at equal angles in relation to the circumferential direction. Moreover, the ribs are integrated on corrugated angled parts on the pipe wall inner surface.</p> |
