| 摘要 |
PURPOSE:To automatically control the distance between a tip and an object to be welded, by controlling a torch position based on the welding current, electrode delivery speed and a voltage between the tip and the object to be welded, in a gas shield wear electrode type arc welding. CONSTITUTION:In a torch 1, shield gas blows from a nozzle 4 at the external circumference of a tip 3 and a wire 6 is fed in a speed (v), and a distance between an object 12 to be welded and the tip 3 is adjusted with an upper and lower transfer device 11. The speed (v) is detected at a rotation detector 15, a voltage V between the tip 3 and the object 12 is detected at a voltage detector 18, and a welding current I is detected at a current detector 20 and they are inputted to an electronic computer 17 respectively via A/D converters 16, 19 and 21. The computer 17 is provided with a setter 22 to set the distance LO between the tip and the object to be welded which should be kept constant, and obtains the sum of the wire projecting length Ex and the arc length L. The power supply 25 is controlled so that the difference between the sum and the LO comes to zero via a converter 24 to drive the device 11. |
