APPARATUS FOR AUTOMATIC CONTROL OF POSITION OF WELDING HEAD Russian patent published in 2003 - IPC

FIELD: automatization of welding processes. SUBSTANCE: apparatus for automatic control of position of welding head having electrode includes first, second and third lines for controlling position of welding head. First line includes connected in series: power source of electric current arc; welding circuit shunt; welding current pickup; band filter tuned for oscillation frequency of electrode; first synchronous detector; first low-frequency filter; scanning phase pickup; oscillator; connected in series adder; first amplifier and drive unit for moving welding head across butt. Second inlet of first synchronous detector is connected with outlet of scanning phase pickup whose inlet is connected with oscillator connected with welding head. Second line includes connected in series: welding voltage pickup; Schmitt trigger; analog switch whose control inlet is connected with outlet of scanning phase pickup; first and second lag networks of first order; comparator of analog signals and smoothing filter. Two outlets of analog switch are connected with respective inlets of first and second lag networks of first order whose outlets are connected with respective inlets of analog signal comparator. Outlet of said comparator is connected with inlet of smoothing filter. Outlet of said filter is connected with first inlet of adder. Third line includes connected in series: band filter tuned for tripled frequency of head oscillations; second synchronous detector; second low- frequency filter; first amplifier with variable gain; frequency tripler. Outlet of first amplifier with variable gain is connected with second inlet of adder. Second inlet of second synchronous detector is connected with outlet of frequency tripler whose inlet is connected with outlet of scanning phase pickup. Apparatus also includes circuit for controlling gain of amplifiers including connected in series; band filter tuned for doubled frequency of electrode oscillations; rectifier; third filter of low frequency; inverter and second amplifier with variable gain. Outlet of third low-frequency filter is connected with control inlet of first amplifier with variable gain and with inlet of inverter. Outlet of inverter is connected with control inlet of second amplifier with variable gain whose inlet is connected with outlet of first low-frequency filter. Outlet of second amplifier with variable gain is connected with third inlet of adder. Inlet of third line for controlling position of welding head and inlet of circuit for controlling gain of amplifiers are connected with outlet of welding current pickup. EFFECT: enhanced quality of welded joint. 1 dwg