| 摘要 |
PURPOSE:To obtain optimum welding current by detecting the substantial pressurization of power feed terminals and changing over selectively the welding current value conforming to the conditions of a spotting position on a timer side in accordance with the detected output. CONSTITUTION:Groups A, B, C, D consisting of the plural 1st spot welding guns are respectively different in the conditions for the spotting position such as the thickness and quality of materials to be welded. The timer 16 is disposed with start switches 9a, 9b, 9c, 9d for making change-over operation in accordance with the groups A, B, C, D and is connected with a phase change-over control part 10 for controlling the phase change-over. The welding conditions conforming to the spotting position of the group A are selected by the operation of the start switch 9a of the timer 16 when the current conduction of the 1st spot gun of the group A is detected by a sensor 8. The optimum conditions are successively selected to the groups B, C, D as well and the respectively optimum welding currents are obtd. |
