The Study To Actualize The Abaxial-Gyral-Focus In Laser Welding

With its advantage that the high speed, the great depth, the little transform of workpiece, equipments is simple, can weld the hard-melt material, easy to control etc. the laser welding is widely used in modern industry of every variety process. In the laser welding, laser beam was focused on surface of the workpiece through laser head. Well-focused laser beam was the key to get high quality welding seam.Because of the quite small diameter of focus, the focus tends to deviate from the seam during welding, which lead to mismatch on welds. However, the conventional laser head was used only for fixation-spot focusing. In this case, the study on new type focus head and improvement on the focusing characteristics of laser are of great significance for promoting the wider use of laser welding and development of metallurgy manufacturing industry.In order to resolve this problem, based on the techniques and principle of laser welding, some factors that affect the welding quality were analyzed. Investigation and survey on focusing characteristics of laser at home and abroad had been viewed. The characteristics of Abaxial-Gyral-Focus welding technique had been demonstrated. Through optical design and mechanical design, a focusing head with rotary focuses had been developed. And devise tow types of scheme. By using the focus head, different radii of the abaxial rotary focuses can be obtained.To prevent the splashing and metal vapor pollution on lens or paraboloid mirror, a gas protection device had been added in the focusing head. At the same time, they can effectively control the plasma to diminish the absorption and refraction of laser power on plasma and increase the efficiency of the laser power.