Patent Number: 8,796,582

Title: Laser welding apparatus and method

Abstract: A laser welding apparatus includes a laser welding unit including a first lens adapted to focus a laser beam; a second lens adapted to diffuse the laser beam to the first lens; and a third lens adapted to guide the laser beam to the second lens. The relative positions of the first lens, the second lens, and the third lens, are adjusted to adjust a diffusion angle and a beam width of the laser beam entering the first lens. The laser welding apparatus performs: actuating the laser welding unit to travel at a predetermined speed along a predetermined trajectory; directing the laser beam at a first welding spot; adjusting the focal length to focus the laser beam at the first welding spot; holding the laser focal spot size substantially constant; and directing the laser beam at a second welding spot after completion of welding for the first welding spot.

Inventors: Kawai; Hitoshi (Atsugi, JP), Hamaguchi; Yuji (Isehara, JP), Sakurai; Tatsuya (Yokohama, JP)

Assignee: Nissan Motor Co., Ltd.

International Classification: B23K 26/00 (20140101); G02B 7/02 (20060101)

Expiration Date: 8/05/12018