APPARATUS FOR AUTOMATIC CONTROL OF WELDING HEAD POSITION Russian patent published in 2002 - IPC

FIELD: automatization of welding processes, possibly gas-shield welding and welding under flux layer at dressing edges and angular seams. SUBSTANCE: apparatus includes first line for controlling position of welding head having connected in series: shunt 2 of welding circuit; pickup 3 for detecting welding current value; band filter 4 tuned for frequency of electrode oscillation; synchronous detector 5; low frequency filter 6. Second input of synchronous detector 5 is connected with output of pickup 7 for detecting scanning phase whose inlet is connected with oscillator 8. Amplifier 10 and drive unit 11 for crosswise moving head relative to butt are connected in series. Second line for controlling position of welding head includes connected in series: pickup 12 for measuring welding voltage; Schmidt trigger 13; analog switch 14 whose control inlet is connected with outlet of pickup 7 for detecting scanning phase. Two outputs of analog switch 14 are connected with respective inlets of first 15 and second 16 delay-action first-order links whose outlets are connected with respective inlets of comparator 17 for comparing analog signals. Outlet of comparator 17 is connected through smoothing filter 18 with second amplifier 19 whose outlet is connected to drive unit 20 for normal correction relative to butt. EFFECT: enhanced quality of welded joint at welding by short circuiting. 2 dwg