JPS5570477A - Control method of wire position in automatic narrow gap welding - Google Patents

Abstract

PURPOSE: To perform the captioned welding which is even over the entire length of the weld line and causes less defects by converting the video signal of the arc generated at the wire end part to image information and inputting this to an electronic computer thereby calculating the position in the groove width direction of the wire end part.

CONSTITUTION: In automatic narrow gap welding, the image of the arc 14 generated at the end part of a wire 13 is picked up with an image pickup unit 11. Based on the video signal outputted by the unit 11, drive units 9, 10 are controlled in real time by an electronic computer. Next, the position or oscillating angle in the groove width direction of the wire 13 is so automatically controlled as to be positioned to the normal position leaving the specified spacing from the groove edge 23 of base metals 1 through controlling of the units 9, 10. Hence, even if any fluctuations in the distance between the groove edge and the wire end part owing to winding habit of the wire which is difficult to predict prior to welding or thermal deformation of the base metals occur during progression of welding operation, the end part of the wire may be corrected accurately to the normal position and the even welding virtually free from defects such as over- or under-penetration and blowholes accomplished over the entire length of the weld line.

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