| 摘要 |
PROBLEM TO BE SOLVED: To enhance a degree of adhesion of a polar column and a bushing by forming a melting area interface between a bushing and a polar column base material in an almost W shape when a terminal of the polar column connected to a plate group is welded to a lead bushing formed in a cover of a battery jar. SOLUTION: An electrode plate group where positive and negative electrode plates and separators are alternately superposed on each other is housed in a battery jar compose of plural cell chambers, and a polar column 4 is connected to the plate group. A lead bushing 2 is formed in a battery cover to cover the battery jar by insert molding, and this bushing 2 is inserted into the polar column 4, and wedding is performed. At this time, a tip part of the polar column 4 is formed in a shell shape so that an outside diameter of the polar column 4 opposed to an upper end part of the bushing 2 becomes about 75 to 85% to an inside diameter of a bushing upper end part, and the tip part of the polar column 4 is projected from an upper end of the bushing 2 so that a clearance 6 exists on its periphery. When the polar column 4 and the bushing 2 are welded together in this condition, an interface of a melting area 8 is formed in an almost W shape, and a degree of adhesion of the polar column 4 and the bushing 2 can be enhanced. |
