| 摘要 |
PURPOSE:To prevent invasion of water through a shelf mounting part and to reinforce a box body, by a method wherein a step part is formed on the inner peripheral part of a box body having an opening at the upper part, a form for supporting a shelf is placed on the step part, and a shelf plate is placed on the form body. CONSTITUTION:A box body 2 made of synthetic resin such as FRP is formed such that a lower body 5 formed in the shape of a container with a bottom and having an opening at its upper part and a cylindrical upper body 7 having an opening part 1 at its upper part are joined together by means of flanges. A step part 3 is formed on the inner peripheral part of the lower body 5, the peripheral part of the form body 4 for supporting a shelf is placed on the step part 3, and a shelf 17 is placed on the form body 4. This prevents invasion of water through the mounting part of the form body for supporting the shelf and permits reinforcing of the box body 2. |
