| 摘要 |
PURPOSE:To ensure and reinforce the welding between a battery case and a cover and improve the property of sealing by fitting the battery case to the cover so that the tip of the aperture section of the battery case can be protruded from the upper end on the external surface section of the cover and starting welding in the state. CONSTITUTION:First of all, a negative electrode, separator, separation paper, positive electrode, etc. are inserted in a battery case and then the battery case 4 and a cover 5 are fit together so that the tip of the aperture section of the battery case 4 can be protruded from the upper end on the external surface section of the body section 6 of the cover 5. Besides, they are heated by heating means, such as a plasma arc in this state and are welded. Thus, the section protruded from the upper end of the cover 5 of the battery case 4 is melted first and covers the upper end on the external surface section of the body section 6 of the cover 5. The welding between the battery case 4 and cover 5 advances in this state. Furthermore, since the tip of the aperture section of the battery case 4 is melted first and covers the upper end on the external surface section of the body section 6 of the cover 5, imbedding welding is possible by the melting pool of the previously melted battery case even when there is a slight gap between the battery case 4 and the cover 5. |
