METHOD AND DEVICE FOR DIAGNOSTICS AND QUALITY CONTROL OF LASER WELDING Russian patent published in 2005 - IPC

FIELD: laser welding equipment.

SUBSTANCE: as welding tool laser beam is used. Number of welding point, current position, seam length or melting space are identified by counting signals of welding process presence and comparing these to supporting time counts. Number of welded seam is identified on basis of welding stop signal or open seam edge signal or closed seam edge signal appropriately for welding technology. Number of welded product is identified on basis of number of welded seams and/or lengths thereof. Probability of occurrence of non-solidity defects or reasons of decrease of laser equipment nodes resource are determined for current welding technology on basis of equality or exceeding of sixth threshold value by total signal I_t. exceeding of edges of welded parts is determined by threshold amplitude selection of signals I_i of welded parts, tracked appropriately for current welding technology from front and sides of joint trajectory. Actual or possible from pre-threshold comparison reasons of defect are identified on basis of appearance of signals of threshold or pre-threshold unacceptable excesses of edges, deviations from joint, space width, decreases of laser emission intensiveness levels, amplitude, length, frequency of intensiveness signals of laser charge, increase of welding speed or unacceptable changes of laser spot diameter. Actual or pre-threshold based possible reasons of overheating and exhausts are identified on basis of appearance of signals of threshold or pre-threshold levels of unacceptable excesses of intensiveness of laser emission, amplitude, length, frequency of signals of laser charge, decrease of welding speed and unacceptable changes of laser spot diameter. Appropriately for current welding technology signals of unacceptable signal states and their actual or possible reasons are recorded for corrections of welding process in real time scale or re-welding of defect portion or stopping process in case of long disruption of optimal welding process and signals for automatic control of laser welding process are formed by adaptive amplitude change, laser charge length, welding speed, pulses frequency and laser emission focusing. Device is provided with laser block with laser beam intensiveness indicator, laser charge current indicator, positioned in power source block, and electronic synchronization block. Operation block is electrically connected by input and output to infrared converter through electronic

synchronization block, which is connected to input and output of control block, laser charge current indicator and laser beam intensiveness indicator. Infrared converter is made with possible orientation by areas of surfaces adjacent areas tracking areas, positioned along drive of relative movement of laser beam along joint, in front and on the sides of joint trajectory or relatively to beam axis for controlling approaches to seam edge, to ending of seam of solid metal of closed edge and to ending of seam of edge of closed edge, vicinity of surface of heat track of formed welding tub, vicinity of surface of laser spot focusing, vicinity of heat tracks of controlled laser block surfaces for diagnosing their abnormal modes of operation and deviations.

EFFECT: higher quality, lower costs, higher speed of operation, higher personnel safety, higher efficiency.

2 cl, 1 dwg