| 摘要 |
PROBLEM TO BE SOLVED: To provide a tubular structure body of high robustness.SOLUTION: A tubular structure body 10 includes a plurality of tubular partial structure bodies 11-14 arranged in continuous manner, and each partial structure body includes polygonal upper end parts 11a-14a, lower end parts 11b-14b of the same shape as the upper end parts, and side parts 11c-14-c extending between them. The first end part is skewed against the second end part by a specified angle, and a partial side part 21 is provided between each side of the first end parts and each side of corresponding second end parts. At each partial side part, a valley fold line 23 is formed on a diagonal line, and a mountain fold line 22 is formed on both sides of each partial side part. Angles between the mountain fold line of each partial side part and a flat surface where the first end part is positioned and a flat surface where a second end part is positioned is &thetas;-&thetas;, being identical. The angle &thetas;at the partial structure body positioned at one end part of the tubular structure body is smaller than the angles &thetas;-&thetas;at the other partial structure bodies while the angle &thetas; for all the partial structure bodies is 20°-60°. |
