| 摘要 |
PURPOSE:To obtain a beam member having an exceedingly high rigidity by molding the top edge parts so as to be depressed gradually towards the terminal edge close to the right and left edges and installing a starting-up rib between the bottom parts. CONSTITUTION:A flat steel plate is roll-molded into wave form on the section so that the top edge pats 1a and the bottom parts 1b are formed alternately over the whole length. Then, each top edge part 1a is press-molded so as to be gradually depressed towards the terminal edge close to the right and left edges. In said depressed molding, a strarting-up rib 4 is formed between the bottom part 1b. Said beam member is an installation member 2 and fixed through spot welding or arc welding by the application onto a door inner panel or pillars. Therefore, no joint part exists on the body, and since the door panel is reinforced by the starting-up rib, the strength of the door panel can be improved markedly. |
