| 摘要 |
PURPOSE:To detect and warn a fact that a slag bath depth is too small, and to eliminate a judgment error for throwing in a slag by detecting a temperature variation of an atmosphere of the upper part of a slag bath in an electroslag welding, by a pyroelectric infrared sensor, and comparing it with a reference voltage. CONSTITUTION:A copper patch is placed on both sides of a gap between materials to be welded 1, 2, and a bottom part, and a slag is thrown in. A welding wire 6 is fed in from a non-consumable nozzle 7, a slag 5 is melted by a DC constant-voltage current, and its bottom part molten metal 4 is coagulated 3 successively and welded. In that case, the molten slag 5 is coagulated partially on the surface of the copper patch, and depth of the slag bath 5 becomes shallow gradually. At that time, a splash 19 of the slag and an arc 20 are generated. These phenomena are caught by a voltage variation of a pyroelectric type sensor 10, and in case when it exceeds a reference voltage, a warning lamp 12 is lighted. It will suffice that a worker throws in an additional slag by a frequency of this warning, and the throwing-in time is decided more exactly than a conventional decision by a visual observation. |
