| 摘要 |
PURPOSE:To eliminate the thermal effect of welding to the inner portion of a cell and to enable welding of high mechanical strength by performing resistance welding with a constant power welding source so as to keep the heat generated in the welded portion constant. CONSTITUTION:One end portion of a lead plate 3 made of stainless steel is placed on the negative electrode terminal plate 2 of a flat type lithium cell 1, and a pair of welding electrodes 4a, 4b made of chromium copper separated by a distance [t] to each other are contacted onto the said end portion with a pressure, and the said end portion is welded to the electrode plate 2 with a constant power welding source so as to keep the heat generated in the welded portion constant. Electric circuits of whole device including an example of constant power source are shown in the figure. The electric power is inputted to a power transistor section 6 to convert to a 2-phase AC power, and applied between the paired welding electrodes 4a, 4b after reconverted to DC through a step-up transformer 7 and a rectifier circuit 8. Thereby the lead member can be resistance welded to the terminal plate of the cell with high mechanical strength and the thermal effect to the inner portion of the cell can be minimized. |
