| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a cost by reducing ancillary parts of an invert panel, and improving moldability. SOLUTION: In this invert panel 10 arranged in the lowest bottom part of a pipeline 101, a rib 21 continuously extending in the lengthwise direction is integrally molded on the reverse of a long size panel body 10A.</p> |
