摘要 |
PROBLEM TO BE SOLVED: To enhance fireproof performance by enhancing supporting performance of a fireproof board. SOLUTION: A fastening bolt 38 is fastened into a female screw portion 42A, which is inserted into a through-hole 48 of the fireproof board 34, through an attachment hole 62 of a second holding portion 44B. Thus, the fireproof board 34 is held in the state of being sandwiched between the first and second holding portions 42B and 44B. The first and second holding portions 42B and 44B are brought into surface contact with the fireproof board 34; and an area of the contact with the fireproof board 34 is increased for a reduction in stress acting on a portion-to-be-held of the fireproof board 34. This inhibits the portion-to-be-held of the fireproof board 34 from being broken or damaged. COPYRIGHT: (C)2011,JPO&INPIT |