Method for avoiding interference of welding equipment, and device for controlling welding equipment

A method for avoiding interference of welding equipment, when the welding equipment including an articulated robot having a pair of welding electrodes capable of changing a distance between tip ends thereof is pulled out of a workpiece, for avoiding the interference between the pair of welding electrodes and the workpiece, the method comprising:

• with a workpiece cross-section as a reference, the workpiece cross-section being cut along a plane including an electrode straight line and a pull-out straight line, the electrode straight line connecting the tip ends of the pair of the welding electrodes separated from each other, the pull-out straight line intersecting with the electrode straight line and extending in a direction of pulling out the welding equipment from the workpiece,
• a reference parallel line creation step of creating a pair of parallel lines that are respectively in contact with outer edges of the workpiece cross-section without traversing the workpiece cross-section and that are located on an extension plane of the workpiece cross-section;
• a first determination step of comparing a width between the pair of parallel lines that have been created in the reference parallel line creation step with a maximum separation threshold of the welding electrodes, the maximum separation threshold of the welding electrodes being a value obtained by subtracting a minimum clearance necessary when the pair of welding electrodes are pulled out of the workpiece from a maximum distance between the tip ends, and determining whether the maximum separation threshold is larger than the width between the parallel lines;
• a pull-out direction determination step of determining a direction of the parallel lines as a pull-out direction, in a case where the maximum separation threshold is larger than the width between the parallel lines in the first determination step;
• and
• a control step of controlling the articulated robot to move the pair of welding electrodes in the pull-out direction determined in the pull-out direction determination step to pull the pair of welding electrodes out of the workpiece.