Abstract
Laser welding systems have been installed in many assembly lines because of small welding distortions. Nonetheless, desires to produce earth-friendly automotive components such as fuel injectors with low volume of residual hydrocarbons in exhaust emissions require higher accuracy of microns or sub-microns order to maintain their function. For examples, circularity deviation of such an injector after welding is requested to be less than 1 micrometer.
Laser welding is a processing with small distortion, however, making the distortion smaller is critical to meet such a high level objective. In this paper, we consider the deformation mechanism by using numerical analyses and experiments, and propose a new method, twin beams method, to decrease the deviation of circularity. Twin beams, which is separated by 90 degrees, obtain a smaller deviation of circularity because of canceling expansion and shrinkage during the welding process. This method is brought into production facilities.
