| 摘要 |
PROBLEM TO BE SOLVED: To form a sound weld zone by continuously emitting a laser beam timewise, constantly changing the output while the average output is maintained in a range capable of through welding, and thereby repeating forced exhaust of the zinc vapor through suppression of zinc vapor generation and change in the size of a molten pool and a key hole. SOLUTION: Change in output for the purpose of exhausting zinc vapor by changing the size of a molten pool and a key hole is so controlled that the maximum and the minimum output is 25% or more of the average output and that the number of times in repeating the change is not less than ten times per second. In addition, scattering of spatter is suppressed by eliminating the continuous state of zero output, and also a welding width is maintained in a range that enables the strength to be fully obtained. Further, the use of a continuously generating YAG laser is desirable that is excited by a flash lamp. By continuously changing a current supplied to the flash lamp, a continuously changing laser output pattern can be obtained. |
