Page 1 - Laserline-Case-Study-Faster-brazing-in-the-roof-joint
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Faster Brazing in the Roof Joint
Task Result
Since the mid-90s brazing has been used in automotive Both the brazing speed and the joint quality were
manufacturing. The advantages of brazing are most increased using the Laserline diode laser. By working in
apparent when it is used in class A show surfaces. Low the focus of the top hat laser beam, a better distribution of
warpage, a stiff joint ready for the paint shop, and almost the power density into the boundaries of the joining
no post-processing make it a unique process. Compared partners was achieved. With the diode laser, edge notches
to laser welding or spot welding, laser brazing improves were reduced by 75 percent and maximum process speed
the aesthetics of a joint so dramatically that the usual increased to 4.4 m/min. Volkswagen decided to replace all
plastic strip needed to cover it can be omitted. The YAG lasers used in the Touran production line with 6 kW
brazing process was first made possible by fiber-coupled, diode lasers. Today, Volkswagen Group uses numerous
lamp-pumped Nd:YAG lasers. In 2001 the diode laser diode lasers from 3 to 6 kW worldwide.
made its debut as a brazing tool in the manufacturing of
the tailgate of the Audi A3. Typical process speeds were
initially 2.4 m/min. To increase production figures,
Volkswagen set a goal of improving brazing speed without
compromising quality.
Process
At the VW Touran production line in Wolfsburg, a process
comparison was conducted between a 4 kW YAG laser
and Laserline’s 6 kW diode laser. While the existing YAG Material: Zinc coated steel sheets
laser used a defocused beam, the new diode laser was Task: Increased process speed for laser brazing
set up with the beam in the focus position and a 3.2 mm of roof joints
diameter focus. The trial examined the quality of the joint Laser: LDF 6000-100
at higher process speeds as well as the process stability in Optics: Tactile brazing head with CuSi3 filler wire
series production.
Brazing speed: 4.4 m/min
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