| 摘要 |
PURPOSE:To reduce weight of a grid by forming an expanded grid for lead- acid battery which width and thickness of small bone are gradually reduced toward lower main bone from upper main bone. CONSTITUTION:The thickness of a roll sheet 7 comprising lead-calcium alloy is gradually reduced from position A forming an upper main bone 2 and a lug 3 to position B forming a lower main bone 4. Zigzag rifts having reduced spaces corresponding to thickness are formed, then expanded to make an expanded grid 1 for a lead-acid battery. Width W1 and W2, and thickness T1 and T2 of small bones 5 and 6 are gradually reduced toward lower main bones 4 from upper main bones 2, the ratio of cross section S1 of 5 and cross section S2 of 6, S2/S1, is specified to 0.25-0.5. Therefore, weight of the grid 1 is reduced, current density of small bones 5 and 6 is uniformed. |
