| 摘要 |
PURPOSE:To extend the life of a spot welding robot and to improve welding quality by keeping the error of the robot from the normal in the pressurizing direction of the spot gun of said robot within a small range and to maintain the torque of the robot arm arising from the normal error at a specified value or below. CONSTITUTION:Materials 11 to be welded are spot-welded on a lower electrode 10 by a spot gun 1 attached to the arm 4 of a welding robot 3. Torque arises in the robot 3 when the gun 1 shifts from the normal direction Z by theta. The torque is detected by torque detectors 12, 13 provided in the juncture between the arms 4 and 5. The detected values are compared with the set values of level setters 17, 18 in comparators 19, 20 of a control device 16 and when the normal error exceeds a prescribed value, a signal is emitted to a robot control panel 21 to emit an alarm by an alarm 22 and to stop automatically the welding operation, thereby preventing the damage of the robot and the deterioration in the quality of the weld zone. |
