| 摘要 |
PROBLEM TO BE SOLVED: To prevent electrolyte from being leaked and improve reliability in operation by a method wherein each of inner lid and an upper lid is provided with a groove and a rib-like projection so as to be fitted to each other. SOLUTION: An inner lid 3 having a continuous groove 4 at a position enclosing a circumference of a safety valve 5 in a lead acid battery and an upper lid 1 having a rib-like projection 2 continuous in compliance with the shape of the groove are fitted to each other at the groove 4 and the projection 2. With such an arrangement as above, even if a path of a clearance between the upper lid 1 and the inner lid 3 is elongated and then electrolyte is leaked out of the safety valve 5, its leakage out of the battery is hardly produced. In addition, it is preferable that the rib-like projection 2 is in an annular form. Further, it is preferable that a clearance between the projection 2 and the groove 4 is 0.3mm or more. If the clearance is narrower than this value, the electrolyte rises up through the clearance due to a phenomenon of capillary action and then the electrolyte flows out of the battery. |
