| 摘要 |
PURPOSE:To detect the length of a consumable electrode projecting from a torch with a simple mechanism in the stage of sensing by applying two kinds of voltages superposedly to the electrode, and obtaining the spot position information on the work according to the conducting state between the electrode and the work. CONSTITUTION:A prescribed voltage is applied from a voltage applying means 203 to a consumable electrode 209. Either of an electric power source 205 for welding or a high voltage power source 206 for detection is selectively connected via a selection switch 204 to this means 203. The power source 206 is connected to the work W via an electric current sensor 207. The sensor 207 detects the change in the current in accordance with the discharging of the electrode 209 and applies a signal to a controlling box 400. In the stage of sensing, the box 400 changes over a selection switch 204 to the detecting power source 206 side to move a torch 109 closer to the welding device. The conducting state of this time is detected with the sensor 207, whereby the spot position information on the work W is obtained. This is converted to an electrode length, in accordance with this, the means 201 is controlled. |
