| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a focal position control device of a laser welding machine, which sequentially detects the laser reflection light from a welding part and automatically adjusts the focal point based on the light strength. SOLUTION: The device comprises a movable stage 18 for driving a laser torch 12 in an optical axial direction, a converting means which receives the reflection laser light reflected at a work 13 and converts it to an electric signal, and a focal point measuring control part 20. The focal point measuring control part 20 measures the strength of the reflected laser light by the electric signal, and when the measured result exceeds a predetermined threshold, the control part 20 controls the movable stage 18 based on a predetermined adjustment algorithm to make the laser light strength smaller than the predetermined threshold.</p> |
