| 摘要 |
PURPOSE:To improve the leakage resistance of an enclosed type cell by specifying the flatness of the cylindrical upper end face of a closed end cylindrical metallic case within the specific limits. CONSTITUTION:With regard to the flatness of the cylindrical upper end face of a closed end cylindrical metallic case 1, when the upper end face is put between the two geometrical planes parallel to each other and the distance between these two planes is minimum, the distance between the two planes must be <=0.03mm.. The electrolyte usually leaks out through the gap between a gasket 3 and an end sealing lid 2. In this case, if the flatness of the cylindrical upper end face of the metallic case 1 is large, the pressing force against the gasket 3 and the end sealing lid 2 is uneven depending on locations, and the electrolyte leaks out through spots of lower pressures. On the other hand, if the flatness is small, the leakage is prevented. In this way, the leakage resistance can be improved. |
